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Sample records for cultivated limbal stem

  1. Unilateral partial limbal stem cell deficiency: contralateral versus ipsilateral autologous cultivated limbal epithelial transplantation.

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    Vazirani, Jayesh; Basu, Sayan; Kenia, Hemal; Ali, Md Hasnat; Kacham, Santhosh; Mariappan, Indumathi; Sangwan, Virender

    2014-03-01

    To report the outcomes of autologous cultivated limbal epithelial transplantation using the healthy part of the affected eye or the fellow eye as a source of limbal stem cells in patients with unilateral, partial limbal stem cell deficiency (LSCD). Retrospective, nonrandomized, interventional case series. setting: L. V. Prasad Eye Institute, Hyderabad, India. study population: Patients with unilateral, partial LSCD who underwent autologous cultivated limbal epithelial transplantation between 2001 and 2011. intervention: The limbal biopsy was taken either from the healthy part of the limbus of the same eye (ipsilateral group) or from the healthy fellow eye (contralateral group). Cells were cultivated using a xeno-free explant culture technique, and cultivated cells were transplanted onto the affected surface. primary outcome measure: Success of cultivated limbal epithelial transplantation, defined as a completely epithelialized, avascular, and clinically stable corneal surface. Seventy eyes of 70 patients were studied. The mean follow up was 17.5 ± 7 months. In 34 eyes the limbal biopsy was taken from the ipsilateral eye and in the remaining 36 eyes from the contralateral eye. Clinical success was achieved in 70.59% of eyes in the ipsilateral group and 75% of eyes in the contralateral group (P = .79). Limbal transplant survival rates at the final follow-up visit were 65.1% ± 0.09% in the ipsilateral group and 53.6% ± 0.12% in the contralateral group (P = .74). Ocular surface restoration in partial LSCD is possible with cell-based therapy. Outcomes are similar irrespective of whether the limbal biopsy is taken from the healthy part of the ipsilateral eye or the contralateral eye. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Early Results of Autologous Cultivated Limbal Stem Cell Transplantation in Total Limbal Stem Cell Deficiency

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    Mohammad Ali Javadi

    2008-12-01

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    PURPOSE: To report the early results of transplantation of autologous limbal stem cells cultivated on amniotic membrane (AM in patients with total unilateral limbal stem cell deficiency (LSCD. METHODS: Four eyes of 4 patients with total unilateral LSCD confirmed with impression cytology underwent transplantation of autologous limbal stem cell cultivated on AM. At each follow up visit, a complete eye examination with special attention to recurrence or regression of vascularization, corneal opacification, and epithelial defect healing was performed. Digital imaging was performed at each follow up visit. Impression cytology was repeated in all cases after surgery. RESULTS: The patients were followed for 5-13 months. Visual acuity improved in all cases. Decrease in corneal opacification and vascularization was obvious in 3 cases with coverage of the cornea with corneal epithelium. Sectoral conjunctivalization was evident in these 3 cases, however the corneas were ready for transplantation. The procedure failed in one case with total corneal conjunctivalization. CONCLUSION: Transplantation of autologous stem cells cultivated on AM seems to be an effective way for total LSCD. More definite judgment needs longer follow up together with long-term results of corneal transplantation in these patients.

  1. Limbal Stem Cell-Sparing Corneoscleroplasty with Peripheral Intralamellar Tuck: A New Surgical Technique for Keratoglobus

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    Elias Jarade

    2017-04-01

    Full Text Available Purpose: To describe the technique of limbal stem cell-sparing corneoscleroplasty for the management of advanced keratoglobus. Methods: A patient with bilateral advanced keratoglobus, with best-corrected visual acuity of 20/400 in the right eye and 20/200 in the left eye, underwent limbal stem cell-sparing corneoscleroplasty of the right eye. Initially, a 360-degree limbal incision with 200-μm depth was created, followed by a sublimbal tunnel dissection into the sclera, in order to conserve stem cells. Next, a limbus-to-limbus lamellar keratectomy at 200-μm depth was performed. Meanwhile, a donor corneoscleral button with preserved endothelium of the central 8 mm was fashioned. Prior to suturing the donor corneoscleral graft using a modified suturing technique to cover its scleral component, a full-thickness trephination of 8-mm diameter was completed in the central host cornea. Results: Reepithelialization occurred within the first week. No episodes of rejection, intraocular pressure spikes, or epithelial breakdown were observed postoperatively. At the 6-month follow-up, the patient had 20/70 best-corrected vision and a smooth cornea with regular astigmatism on topography. Conclusion: Limbal stem cell-sparing corneoscleroplasty is a single-step technique for restoring the structural integrity of the cornea in advanced keratoglobus while preserving the host limbal stem cells.

  2. Human pluripotent stem cell-derived limbal epithelial stem cells on bioengineered matrices for corneal reconstruction.

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    Mikhailova, Alexandra; Ilmarinen, Tanja; Ratnayake, Anjula; Petrovski, Goran; Uusitalo, Hannu; Skottman, Heli; Rafat, Mehrdad

    2016-05-01

    Corneal epithelium is renewed by limbal epithelial stem cells (LESCs), a type of tissue-specific stem cells located in the limbal palisades of Vogt at the corneo-scleral junction. Acute trauma or inflammatory disorders of the ocular surface can destroy these stem cells, leading to limbal stem cell deficiency (LSCD) - a painful and vision-threatening condition. Treating these disorders is often challenging and complex, especially in bilateral cases with extensive damage. Human pluripotent stem cells (hPSCs) provide new opportunities for corneal reconstruction using cell-based therapy. Here, we investigated the use of hPSC-derived LESC-like cells on bioengineered collagen matrices in serum-free conditions, aiming for clinical applications to reconstruct the corneal epithelium and partially replace the damaged stroma. Differentiation of hPSCs towards LESC-like cells was directed using small-molecule induction followed by maturation in corneal epithelium culture medium. After four to five weeks of culture, differentiated cells were seeded onto bioengineered matrices fabricated as transparent membranes of uniform thickness, using medical-grade porcine collagen type I and a hybrid cross-linking technology. The bioengineered matrices were fully transparent, with high water content and swelling capacity, and parallel lamellar microstructure. Cell proliferation of hPSC-LESCs was significantly higher on bioengineered matrices than on collagen-coated control wells after two weeks of culture, and LESC markers p63 and cytokeratin 15, along with proliferation marker Ki67 were expressed even after 30 days in culture. Overall, hPSC-LESCs retained their capacity to self-renew and proliferate, but were also able to terminally differentiate upon stimulation, as suggested by protein expression of cytokeratins 3 and 12. We propose the use of bioengineered collagen matrices as carriers for the clinically-relevant hPSC-derived LESC-like cells, as a novel tissue engineering approach for

  3. Spatial distribution of niche and stem cells in ex vivo human limbal cultures.

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    Mariappan, Indumathi; Kacham, Santhosh; Purushotham, Jyothi; Maddileti, Savitri; Siamwala, Jamila; Sangwan, Virender Singh

    2014-11-01

    Stem cells at the limbus mediate corneal epithelial regeneration and regulate normal tissue homeostasis. Ex vivo cultured limbal epithelial transplantations are being widely practiced in the treatment of limbal stem cell deficiency. In this report, we examined whether the limbal niche cells that nurture and regulate epithelial stem cells coexist in ex vivo limbal cultures. We also compared the inherent differences between explant and suspension culture systems in terms of spatial distribution of niche cells and their effect on epithelial stem cell proliferation, migration, and differentiation in vitro. We report that the stem cell content of both culture systems was similar, explaining the comparable clinical outcomes reported using these two methods. We also showed that the niche cells get expanded in culture and the nestin-positive cells migrate at the leading edges to direct epithelial cell migration in suspension cultures, whereas they are limited to the intact niche in explant cultures. We provide evidence that C/EBPδ-positive, p15-positive, and quiescent, label-retaining, early activated stem cells migrate at the leading edges to regulate epithelial cell proliferation in explant cultures, and this position effect is lost in early suspension cultures. However, in confluent suspension cultures, the stem cells and niche cells interact with each another, migrate in spiraling patterns, and self-organize to form three-dimensional niche-like compartments resembling the limbal crypts and thereby reestablish the position effect. These 3D-sphere clusters are enriched with nestin-, vimentin-, S100-, and p27-positive niche cells and p15-, p21-, p63α-, C/EBPδ-, ABCG2-, and Pax6-positive quiescent epithelial stem cells.

  4. Proteomic analysis as a means to approach limbal stem cell biology in a search for stem cell markers.

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    Honoré, Bent; Vorum, Henrik

    2014-04-01

    The cornea consists of three main layers: an outer surface epithelium, the stroma, and the endothelium. A clear cornea is necessary for optimal vision and is maintained and repaired from limbal epithelial stem cells located in the limbus between the cornea and the sclera. Diseases and injury may result in deficiency of the stem cells impairing their ability to renew the corneal epithelium. Patients with limbal stem cell deficiency experience chronic pain and ultimately blindness. Attempts to treat the disease are based on replacement of the stem cells by transplantation or by culturing the stem cells. We here review the proteomic techniques that so far have been used to approach characterization of limbal stem cells and markers to identify them. It is apparent that the field is in a rather inchoate state due to the scarcity and relative inaccessibility of the stem cells. However, the importance of revealing limbal stem cell biology and identifying stem cell biomarkers calls for greater use of emerging methodology. Strategies for future studies are discussed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. System for tracking transplanted limbal epithelial stem cells in the treatment of corneal stem cell deficiency (Conference Presentation)

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    Boadi, Joseph; Matcher, Stephen; MacNeil, Sheila; Sangwan, Virender S.

    2016-04-01

    The prevailing hypothesis for the existence and healing of the avascular corneal epithelium is that this layer of cells are continually produced by stem cells in the limbus and transported onto the cornea to mature into corneal epithelium. In the event that the cornea is damaged and the limbal stem cell population is severely reduced, this condition known as Limbal Stem Cell Deficiency and can lead to blindness. There are numerous treatments but most have high long term failure rates. Most treatment methods include the transplantation of limbal stem cells into damaged limbus with hope of repopulating the region and regenerating at healthy corneal epithelium. Optical Coherence Tomography (OCT) is well known for its high resolution in vivo images. A bespoke OCT has been built to investigate the trajectories of these limbal stem cells after transplantation to see whether if they do repopulate the damaged limbus or not. In the experimentation magneto-labelling was used to track the limbal stem cells. For the magneto-labelling a mixture of limbal stem cells and cornea epithelium are cultured with super paramagnetic iron (Fe3O4) nanoparticles (20-30nm in size) for 24hours, to allow for uptake. The cells are then transplanted onto the denuded cornea. The transplanted cell mixture with the encapsulated magnetic nanoparticles is actuated with an external magnetic field 0.08T leading to a phase modulation on the signal. A Phase sensitive Magneto-motive OCT is used to locate the transplanted cells. The location of the cells with embed SPIOs were located both in 2D and 3D.

  6. Short-term uvb-irradiation leads to putative limbal stem cell damage and niche cell-mediated upregulation of macrophage recruiting cytokines

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    Maria Notara

    2015-11-01

    Full Text Available Ultraviolet light B (UVB-irradiation is linked to various ocular pathologies such as limbal stem cell defects in pterygium. Despite the large circumstantial evidence linking UVB irradiation and limbal epithelial stem cell damage, the precise molecular responses of limbal stem cells to UVB irradiation are unclear. Here the effect of UVB irradiation on the putative stem cell phenotype, limbal niche cells and the subsequent effects on corneal (lymphangiogenic privilege were investigated. Primary human limbal epithelial stem cells and fibroblasts were irradiated with 0.02 J/cm2 of UVB, a low dose corresponding to 3 min of solar irradiation. UVB irradiation caused significant reduction of limbal epithelial and limbal fibroblast proliferation for 24 h, but apoptosis of limbal epithelial stem cells only. Moreover, UVB induced stem-like character loss of limbal epithelial cells, as their colony forming efficiency and putative stem cell marker expression significantly decreased. Interestingly, limbal epithelial cells co-cultured with UVB-irradiated limbal fibroblasts also exhibited loss of stem cell character and decrease of colony forming efficiency. Conditioned media from limbal epithelial cells inhibited lymphatic endothelial cell proliferation and tube network complexity; however this effect diminished following UVB irradiation. In contrast, pro-inflammatory and macrophage-recruiting cytokines such as TNFα, IFNγ and MCP1 were significantly upregulated following cell irradiation of limbal fibroblasts. These data demonstrate the key role of the limbal stem cell niche in response to UVB and subsequent (lymphangiogenic and inflammatory events. These data suggest that the known pro(lymphangiogenic effect of UVB irradiation in pterygium is not linked to a direct up-regulation of pro-angiogenic cytokines, but rather to indirect macrophage-recruiting cytokines being upregulated after UVB irradiation.

  7. Comparative analysis of different feeder layers with 3T3 fibroblasts for culturing rabbits limbal stem cells

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    Hui-Xian Wang

    2017-07-01

    Full Text Available AIM: To explore the possibility of human umbilical cord mesenchymal stem cells (hUCMSCs, human umbilical vein endothelial cells (hUVECs, human dental pulp stem cells (hDPSCs and human periodontal ligament stem cells (hPDLSCs serving as feeder cells in co-culture systems for the cultivation of limbal stem cells. METHODS: Different feeder layers were cultured in Dulbecco’s modified Eagle’s medium (DMEM/F12 and were treated with mitomycin C. Rabbits limbal stem cells (LSCs were co-cultured on hUCMSCs, hUVECs, hDPSCs, hPDLSCs and NIH-3T3, and then comparative analysis were made between each group to see their respective colony-forming efficiency (CFE assay and immunofluorescence (IPO13,CK3/12. RESULTS: The efficiency of the four type cells in supporting the LSCs morphology and its cellular differentiation was similar to that of NIH-3T3 fibroblasts as demonstrated by the immunostaining properties analysis, with each group exhibiting a similar strong expression pattern of IPO13, but lacking CK3 and CK12 expression in terms of immunostaining. But hUCMSCs, hDPSCs and hPDLSCs feeder layers were superior in promoting colony formation potential of cells when compared to hUVECs and feeder-cell-free culture. CONCLUSION: hUCMSCs, hDPSCs and hPDLSCs can be a suitable alternative to conventional mouse NIH-3T3 feeder cells, so that risk of zoonotic infection can be diminished.

  8. Impression cytology and in vivo confocal microscopy in corneas with total limbal stem cell deficiency

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    Aline Lütz de Araújo

    2013-10-01

    Full Text Available PURPOSES: To describe corneal changes seen on in vivo confocal microscopy in patients with total limbal stem cell deficiency and to correlate them with cytological findings. METHODS: A prospective case series including 13 eyes (8 patients with total limbal deficiency was carried out. Stem cell deficiency was diagnosed clinically and by corneal impression cytology. Confocal images of the central cornea were taken with the Heidelberg Retina Tomograph II, Rostock Corneal Module (Heidelberg Engineering, Heidelberg, Germany. RESULTS: Impression cytology of the cornea revealed conjunctival epithelial cells and goblet cells in all cases. In vivo confocal microscopy showed disruption of normal layers of the corneal epithelium in all eyes. Confocal images showed cells with characteristics of conjunctival epithelium at the cornea in 76.9% of the total. These findings on confocal microscopy were compatible to limbal stem cell deficiency. Additionally, goblet cells, squamous metaplasia, inflammatory cells and dendritic cells were observed. The sub-basal nerve plexus was not identified in any of the corneas. Corneal neovessels were observed at the epithelium and stroma. All cases showed diffuse hyper-reflective images of the stroma corresponding to opacity of the tissue. CONCLUSIONS: Limbal stem cell deficiency had been confirmed by impression cytology in all cases, and 76.9% of the cases could also be diagnosed by in vivo confocal microscopy through the conjunctival epithelial cell visualization on the corneal surface. Frequent confocal microscopy findings were abnormal cells at the cornea (conjunctival epithelial, goblet and inflammatory cells, corneal neovessels and diffuse hyper-reflection of the stroma.

  9. Limbal Stem Cell Transplantation for Gelatinous Drop-like Corneal Dystrophy

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    Hossein Movahedan

    2013-01-01

    Full Text Available Purpose: To report the outcomes of allograft limbal stem cell transplantation for recurrent gelatinous drop-like corneal dystrophy (GDLD. Methods: In this non-comparative interventional case series, 4 eyes of 3 consecutive patients with recurrent GDLD underwent allograft limbal stem cell transplantation. Two eyes underwent concomitant penetrating keratoplasty while the other two underwent simultaneous superficial keratectomy. Main outcome measures were best spectacle corrected visual acuity, intraocular pressure and corneal clarity. Results: Patient age ranged from 28 to 63 years. Mean follow-up after surgery was 23±10 (median, 22; range, 12-36 months. Mean visual acuity improved from 2.70±0.61 logMAR preoperatively to 1.05±0.06 logMAR at final postoperative visit (P=0.066. Intraocular pressure was normal in all eyes at baseline and remained within normal limits at all postoperative visits. All corneas remained smooth and clear during the follow-up period with no episode of rejection or recurrence. All patients maintained ambulatory vision until final follow-up. Conclusion: The present study provides further evidence that limbal stem cell transplantation may be an effective therapeutic alternative in patients with GDLD.

  10. Clinical observation of pterygium excision combined with limbal stem cell transplantation and drug therapy

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    Hai-Jia Xu

    2013-09-01

    Full Text Available AIM: To investigate the effect of pterygium excision combined with autologous limbal stem cell transplantation and drug treatment after the operation.METHODS: A total of 980 eyes of 760 cases underwent pterygium excision, the conjunctival graft with stem cells was interrupted sutured in the limbal sclera planting beds and bulbar conjunctiva. One hundred and sixty-two eyes which relapse again were divided into 2 groups, group A: 1g/L mitomycin C+norfloxacin eye drops for 1-3 months; Group B: dexamethasone eye drops and diclofenac sodium eye drops for 1-3 months or more.RESULTS: One hundred and sixty-two eyes which relapse again were divided into the A and B groups use different medication treatment, Group A: 67 eyes(81.7%were curd, 12 eyes(14.6%relapse again, 3 eyes(3.7%recurrence. Group B: 35 eyes(43.8%were cured, 29 eyes(36.3%relapse again, 16 eyes(20.0%recurrence. The recurrence rate of group A was significantly lower than that of group B(PCONCLUSION: Pterygium excision combined with limbal stem cell transplantation without rejection, safe and effective, with low recurrence rate, postoperative eye drops is particularly important, which could effectively inhibit and reduce the recurrence rate and significantly improve the therapeutic effect.

  11. Culture of Oral Mucosal Epithelial Cells for the Purpose of Treating Limbal Stem Cell Deficiency

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    Tor Paaske Utheim

    2016-03-01

    Full Text Available The cornea is critical for normal vision as it allows allowing light transmission to the retina. The corneal epithelium is renewed by limbal epithelial cells (LEC, which are located in the periphery of the cornea, the limbus. Damage or disease involving LEC may lead to various clinical presentations of limbal stem cell deficiency (LSCD. Both severe pain and blindness may result. Transplantation of cultured autologous oral mucosal epithelial cell sheet (CAOMECS represents the first use of a cultured non-limbal autologous cell type to treat this disease. Among non-limbal cell types, CAOMECS and conjunctival epithelial cells are the only laboratory cultured cell sources that have been explored in humans. Thus far, the expression of p63 is the only predictor of clinical outcome following transplantation to correct LSCD. The optimal culture method and substrate for CAOMECS is not established. The present review focuses on cell culture methods, with particular emphasis on substrates. Most culture protocols for CAOMECS used amniotic membrane as a substrate and included the xenogeneic components fetal bovine serum and murine 3T3 fibroblasts. However, it has been demonstrated that tissue-engineered epithelial cell sheet grafts can be successfully fabricated using temperature-responsive culture surfaces and autologous serum. In the studies using different substrates for culture of CAOMECS, the quantitative expression of p63 was generally poorly reported; thus, more research is warranted with quantification of phenotypic data. Further research is required to develop a culture system for CAOMECS that mimics the natural environment of oral/limbal/corneal epithelial cells without the need for undefined foreign materials such as serum and feeder cells.

  12. Culture of Oral Mucosal Epithelial Cells for the Purpose of Treating Limbal Stem Cell Deficiency.

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    Utheim, Tor Paaske; Utheim, Øygunn Aass; Khan, Qalb-E-Saleem; Sehic, Amer

    2016-03-01

    The cornea is critical for normal vision as it allows allowing light transmission to the retina. The corneal epithelium is renewed by limbal epithelial cells (LEC), which are located in the periphery of the cornea, the limbus. Damage or disease involving LEC may lead to various clinical presentations of limbal stem cell deficiency (LSCD). Both severe pain and blindness may result. Transplantation of cultured autologous oral mucosal epithelial cell sheet (CAOMECS) represents the first use of a cultured non-limbal autologous cell type to treat this disease. Among non-limbal cell types, CAOMECS and conjunctival epithelial cells are the only laboratory cultured cell sources that have been explored in humans. Thus far, the expression of p63 is the only predictor of clinical outcome following transplantation to correct LSCD. The optimal culture method and substrate for CAOMECS is not established. The present review focuses on cell culture methods, with particular emphasis on substrates. Most culture protocols for CAOMECS used amniotic membrane as a substrate and included the xenogeneic components fetal bovine serum and murine 3T3 fibroblasts. However, it has been demonstrated that tissue-engineered epithelial cell sheet grafts can be successfully fabricated using temperature-responsive culture surfaces and autologous serum. In the studies using different substrates for culture of CAOMECS, the quantitative expression of p63 was generally poorly reported; thus, more research is warranted with quantification of phenotypic data. Further research is required to develop a culture system for CAOMECS that mimics the natural environment of oral/limbal/corneal epithelial cells without the need for undefined foreign materials such as serum and feeder cells.

  13. Optimal isolation and xeno-free culture conditions for limbal stem cell function.

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    Stasi, Kalliopi; Goings, DaVida; Huang, Jiayan; Herman, Lindsay; Pinto, Filipa; Addis, Russell C; Klein, Dahlia; Massaro-Giordano, Giacomina; Gearhart, John D

    2014-01-20

    To preserve limbal stem cell (LSC) function in vitro with xenobiotic-free culture conditions. Limbal epithelial cells were isolated from 139 donors using 15 variations of three dissociation solutions. All culture conditions were compared to the baseline condition of murine 3T3-J3 feeders with xenobiotic (Xeno) keratinocyte growth medium at 20% O2. Five Xeno and Xeno-free media with increasing concentrations of calcium and epidermal growth factor (EGF) were evaluated at 5%, 14%, and 20% O2. Human MRC-5, dermal (fetal, neonatal, or adult), and limbal stromal fibroblasts were compared. Statistical analysis was performed on the number of maximum serial weekly passages, percentage of aborted colonies, colony-forming efficiency (CFE), p63α(bright) cells, and RT-PCR ratio of p63α/K12. Immunocytochemistry and RT-PCR for p63α, ABCG2, Bmi1, C/EBPδ , K12, and MUC1 were performed to evaluate phenotype. Dispase/TrypLE was the isolation method that consistently showed the best yield, viability, and CFE. On 3T3-J2 feeders, Xeno-free medium with calcium 0.1 mM and EGF 10 ng/mL at 20% O2 supported more passages with equivalent percentage of aborted colonies, p63α(bright) cells, and p63α/K12 RT-PCR ratio compared to baseline Xeno-media. With this Xeno-free medium, MRC-5 feeders showed the best performance, followed by fetal, neonatal, adult HDF, and limbal fibroblasts. MRC-5 feeders supported serial passages with sustained high expression of progenitor cell markers at levels as robust as the baseline condition without significant difference between 20% and 5% O2. The LSC function can be maintained in vitro under appropriate Xeno-free conditions.

  14. Chemical injury treated with autologous limbal epithelial stem cell transplantation and subconjunctival bevacizumab

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    Cavallini GM

    2014-08-01

    Full Text Available Gian Maria Cavallini,1 Graziella Pellegrini,2 Veronica Volante,1 Pietro Ducange,1 Michele De Maria,1 Giulio Torlai,1 Caterina Benatti,1 Matteo Forlini1 1Institute of Ophthalmology, 2Centre for Regenerative Medicine “Stefano Ferrari”, University of Modena e Reggio Emilia, Modena, Italy Background: Limbal stem cell (LSC deficiency leads to corneal opacity due to a conjunctivalization of the corneal surface. LSC transplantation, which can be followed by corneal keratoplasty, is an effective procedure to restore corneal transparency; however, a common cause of failure of this procedure is neovascularization (NV.Methods: A 59-year-old man with a 21-year history of a corneal chemical burn caused by phosphoric acid in his left eye was examined. He presented with unilateral total LSC deficiency with severe conjunctivalization and a corrected distance visual acuity that was limited to hand motion.Results: We reported the short-term in vivo efficacy of subconjunctival bevacizumab for progressive corneal NV in a patient with LSC deficiency that underwent LSC transplantation. Four months after autologous LSC transplantation and 1 month after the second subconjunctival bevacizumab injection, the patient’s corrected distance visual acuity was 1/10.Conclusion: Subconjunctival injection of bevacizumab can reduce the corneal NV, reducing conjunctival inflammation and supporting restoration of a stable ocular surface that is able to counteract graft failure, with no toxicity for the transplanted LSC. Keywords: stem cells, bevacizumab, limbal stem cell deficiency, transplantation

  15. Preservation of Ocular Epithelial Limbal Stem Cells: The New Frontier in Regenerative Medicine.

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    Lužnik, Zala; Bertolin, Marina; Breda, Claudia; Ferrari, Barbara; Barbaro, Vanessa; Schollmayer, Petra; Ferrari, Stefano

    2016-01-01

    Significant advances have been made in the field of ocular regenerative medicine. Promising stem cell-based therapeutic strategies have been translated into the clinical practice over the last few decades. These new stem cell-based therapies offer the possibility of permanently restoring corneal epithelium in patients with severe disabling and blinding ocular surface disease. The European Union has already classified stem cell-based therapies as "medicinal products". Therefore, manipulation is strictly regulated according to the defined conditions of good manufacturing practice, with the production of stem cell therapeutics at only accredited production sites authorized by the national regulatory agencies. In this regard, as first medical products are licensed for commercial use in Europe enabling a more widespread access to a stem cell-based therapy, the need for safe, validated and reproducible techniques for ex vivo cultured tissue preservation and distribution are coming to the forefront of research. However, these provide various new challenges for biobanking industry such as the retention of viability, good functionality of stem cells and sterility issues. This chapter provides an overview of the current advances in the field of corneal/limbal epithelial stem cell culture preservation techniques using either hypothermic storage or cryopreservation methods, that were used in different culturing steps (from stem cell isolation to the ex vivo epithelial graft preparation), with the reported impact on the post-thawing product recovery.

  16. Culture of human limbal epithelial stem cells on tenon's fibroblast feeder-layers: a translational approach.

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    Scafetta, Gaia; Siciliano, Camilla; Frati, Giacomo; De Falco, Elena

    2015-01-01

    The coculture technique is the standard method to expand ex vivo limbal stem cells (LSCs) by using inactivated embryonic murine feeder layers (3T3). Although alternative techniques such as amniotic membranes or scaffolds have been proposed, feeder layers are still considered to be the best method, due to their ability to preserve some critical properties of LSCs such as cell growth and viability, stemness phenotype, and clonogenic potential. Furthermore, clinical applications of LSCs cultured on 3T3 have taken place. Nevertheless, for an improved Good Manufacturing Practice (GMP) compliance, the use of human feeder-layers as well as a fine standardization of the process is strictly encouraged. Here, we describe a translational approach in accordance with GMP regulations to culture LSCs onto human Tenon's fibroblasts (TFs). In this chapter, based on our experience we identify and analyze issues that often are encountered by researchers and discuss solutions to common problems.

  17. Effects of flow-induced shear stress on limbal epithelial stem cell growth and enrichment.

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    Yun Gyeong Kang

    Full Text Available The roles of limbal epithelial stem cells (LESCs are widely recognized, but for these cells to be utilized in basic research and potential clinical applications, researchers must be able to efficiently isolate them and subsequently maintain their stemness in vitro. We aimed to develop a biomimetic environment for LESCs involving cells from their in vivo niche and the principle of flow-induced shear stress, and to subsequently demonstrate the potential of this novel paradigm. LESCs, together with neighboring cells, were isolated from the minced limbal tissues of rabbits. At days 8 and 9 of culture, the cells were exposed to a steady flow or intermittent flow for 2 h per day in a custom-designed bioreactor. The responses of LESCs and epithelial cells were assessed at days 12 and 14. LESCs and epithelial cells responded to both types of flow. Proliferation of LESCs, as assessed using a BrdU assay, was increased to a greater extent under steady flow conditions. Holoclones were found under intermittent flow, indicating that differentiation into transient amplifying cells had occurred. Immunofluorescent staining of Bmi-1 suggested that steady flow has a positive effect on the maintenance of stemness. This finding was confirmed by real-time PCR. Notch-1 and p63 were more sensitive to intermittent flow, but this effect was transient. K3 and K12 expression, indicative of differentiation of LESCs into epithelial cells, was induced by flow and lasted longer under intermittent flow conditions. In summary, culture of LESCs in a bioreactor under a steady flow paradigm, rather than one of intermittent flow, is beneficial for both increasing proliferation and maintaining stemness. Conversely, intermittent flow appears to induce differentiation of LESCs. This novel experimental method introduces micro-mechanical stimuli to traditional culture techniques, and has potential for regulating the proliferation and differentiation of LESCs in vitro, thereby

  18. Short-term outcome of Boston Type 1 keratoprosthesis for bilateral limbal stem cell deficiency

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    Sayan Basu

    2012-01-01

    Full Text Available This study reports the short-term functional and anatomical outcome of Boston Type 1 keratoprosthesis (Boston Kpro implantation for bilateral limbal stem cell deficiency (LCSD. Retrospective analysis was done on eight eyes of eight patients who underwent Boston Kpro implantation between July 2009 and October 2009. The best corrected visual acuity (BCVA and slit-lamp biomicroscopy findings were assessed at 1, 3 and 6 months postoperatively. All eight eyes retained the prosthesis. BCVA of 20/40 or better was achieved in 8, 6, and 5 eyes at 1, 3, and 6 months, respectively, postoperatively. One patient each developed epithelial defect, sterile stromal melt and fungal keratitis in the late postoperative period associated with antecedent loss of the soft contact lens from the eye. Boston Kpro has good short-term visual and anatomical outcome in patients with bilateral LSCD, provided compliance with postoperative care can be ensured.

  19. Concise review: transplantation of cultured oral mucosal epithelial cells for treating limbal stem cell deficiency-current status and future perspectives.

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    Utheim, Tor Paaske

    2015-06-01

    A number of diseases and external factors can deplete limbal stem cells, causing pain and visual loss. Ten years have passed since the first transplantation of cultured oral mucosal epithelial cells in humans, representing the first autologous cell-based therapy for severe bilateral limbal stem cell deficiency. Its steady increase in popularity since then can be attributed to the accumulating evidence of its efficacy in reverting limbal stem cell deficiency. In this review, the focus is on clinical, and to a lesser degree laboratory, features of cultured oral mucosal epithelial transplants over the past 10 years. Comparisons with other available technologies are made. Avenues for research to stimulate further improvements in clinical results and allow worldwide distribution of limbal stem cell therapy based on oral mucosal cells are discussed. These include storage and transportation of cultured oral mucosal epithelial sheets and in vivo culture of oral mucosal epithelial cells.

  20. ES micro-environment enhances stemness and inhibits apoptosis in human limbal stem cells via the maintenance of telomerase activity.

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    Zhiping Liu

    Full Text Available Our previous work had found that telomerase rejuvenated in the cytoplasm of corneal epithelial cells cultured in embryonic stem cell-conditioned medium, the functional properties of stem-like corneal epithelial cells can be enhanced by co-culturing with embryonic stem cells (ESCs via activation of the integrinβ1-FAK-PI3K/Akt signaling pathway. The goal of this study was to explore the potential molecular mechanisms of the ES micro-environment that enhance the stem cell-like phenotype and inhibit apoptosis in human limbal stem cells (LSC. The LSC were cultured in different media, either CnT-20 medium or CnT-20 +20% ES culture supernatant (ESC-CM. We observed that LSC cultured in ESC-CM had an increased proliferative capacity, greater serial passage capacity, higher colony-forming efficiency (CFE and higher levels of stem cell-associated marker than those cultured in CnT-20. Compared with CnT-20, ESC-CM enhanced the undifferentiated status and inhibited apoptosis in the LSC by promoting the maintenance of telomerase activity, which could reduce the generation of reactive oxygen species (ROS, maintain the membrane potential (Δψm at higher levels and reduce the expression of the p21 protein. Our findings indicated that ESC-CM system induced LSC to maintain a stem cell phenotype and inhibit the process of apoptosis. These effects might partially be achieved via the telomerase-p21-mitochondrial axis and the activation of the FAK/Wnt signaling pathways. This study may have high impact and clinic implication on the expansion of LSC in regenerative medicine, especially for ocular surface reconstruction.

  1. Efficacy of cultivated corneal epithelial stem cells for ocular surface reconstruction

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    Prabhasawat P

    2012-09-01

    Full Text Available Pinnita Prabhasawat,1 Pattama Ekpo,2 Mongkol Uiprasertkul,3 Suksri Chotikavanich,1 Nattaporn Tesavibul11Department of Ophthalmology, 2Department of Immunology, 3Department of Pathology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, ThailandPurpose: To investigate the clinical outcomes of cultivated corneal limbal epithelial transplantation (CLET using human amniotic membrane for corneal limbal stem-cell deficiency.Methods: Prospective, noncomparative case series. Eighteen patients (19 eyes with severe ocular surface diseases were chosen to undergo CLET using human amniotic membrane. Twelve eyes received auto-CLET, and seven eyes received allo-CLET. Clinical outcomes of corneal surface epithelialization, conjunctivalization, inflammation, visual acuity, graft status, and complications were observed.Results: Corneal epithelium cultivated on amniotic membrane (two to four layers was positive for molecular markers p63, ABCG2, CK3, and CK12. The mean patient age was 44.7 ± 15.2 years. A successful clinical outcome, defined as corneal epithelialization without central conjunctivalization or severe inflammation, was obtained in 14 (73.7% of 19 eyes (mean follow-up 26.1 ± 13.5 months; range 6–47. A histopathologic success, defined as absence of goblet cells at the central cornea, was achieved in 12 (63.2% eyes. Clinical failures occurred in five (26.3% of 19 eyes, and histopathologic failures occurred in seven (36.8% of 19 eyes. Survival analysis at 1 year showed that the clinical success rate was 77.9% and the pathological success rate was 72.3%. Fourteen of 19 (73.7% eyes had visual acuity improvements after CLET. Six cases underwent penetrating keratoplasty; five of these grafts remained clear after 20.4 ± 6.9 months (range, 12–31 of follow-up. Complications included infectious keratitis (three cases and recurrent symblepharon (one case. All complicated cases had lid abnormalities. Factors affecting the final clinical

  2. Combined HLA matched limbal stem cells allograft with amniotic membrane transplantation as a prophylactic surgical procedure to prevent corneal graft rejection after penetrating keratoplasty: case report

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    Paolo Capozzi

    2014-09-01

    Full Text Available Purpose. To determine if the use of combined HLA matched limbal stem cells allograft with amniotic membrane transplantation (AMT is a safe and effective prophylactic surgical procedure to prevent corneal graft after penetrating keratoplasty (PK. Methods. We report the case of a 17 years old patient with a history of congenital glaucoma, trabeculectomy and multiple corneal graft rejections, presenting total limbal cell deficiency. To reduce the possibility of graft rejection in the left eye after a new PK, a two step procedure was performed. At first the patient underwent a combined HLA matched limbal stem cells allograft (LAT and AMT and then, 10 months later, a new PK. Results. During 12 months of follow-up, the corneal graft remained stable and smooth, with no sign of graft rejection. Conclusions. In our patient, the prophylactic use of LAT from HLA-matched donors and AMT before PK, may result in a better prognosis of corneal graft survival.

  3. Corneal Differentiation Following HSC70 and HSP72 Expression in Air-Exposed Limbal Stem Cells Cultured on Denuded Amniotic Membrane

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    Parvaneh Mohammadi

    2010-01-01

    Full Text Available Objective: The aim of this study is to create an ex vivo model to examine the expressionof two heat shock protein 70 (HSP70 family members, heat shock protein 72 (HSP72and heat shock constitute protein 70 (HSC70, at the mRNA and protein levels in differentiatingcorneal cells from air exposed limbal stem cells.Materials and Methods: Limbal biopsies were cultured as explants on a cellular amnioticmembrane for 14 days. The cells were then exposed to air for 16 extra additional days.The proposed expression of limbal stem cell markers (p63, ABCG2, corneal markers(K3/12, connexin 43, as well as HSP72 and HSC70 were analyzed by reverse transcription-polymerase chain reaction (RT-PCR at the mRNA level, and by immunocytochemistryand flowcytometry at the protein level both pre and post air exposure. Fresh limbal andcorneal tissues were used as control group.Results: Air exposure decreased expression of p63 and increased expression of K3/K12 indicating an increase in the number of corneal cells. Our data showed that HSP72and HSC70 were expressed at the mRNA level before and after air exposure while theirexpression significantly increased post air exposure at the protein level.Conclusion: We assume HSC70 expression may be related to early and terminal stagesof differentiation in cultured limbal stem cells. In addition, limbal stem cells were protectedduring normal development against oxidative stress thru increased HSP72 expression.These findings may have broader implications in development of therapeutic strategiesfor treating wound healing disorders by induction of HSPs.

  4. Plasma polymer-coated contact lenses for the culture and transfer of corneal epithelial cells in the treatment of limbal stem cell deficiency.

    Science.gov (United States)

    Brown, Karl David; Low, Suet; Mariappan, Indumathi; Abberton, Keren Maree; Short, Robert; Zhang, Hong; Maddileti, Savitri; Sangwan, Virender; Steele, David; Daniell, Mark

    2014-02-01

    Extensive damage to the limbal region of the cornea leads to a severe form of corneal blindness termed as limbal stem cell deficiency (LSCD). Whereas most cases of corneal opacity can be treated with full thickness corneal transplants, LSCD requires stem cell transplantation for successful ocular surface reconstruction. Current treatments for LSCD using limbal stem cell transplantation involve the use of murine NIH 3T3 cells and human amniotic membranes as culture substrates, which pose the threat of transmission of animal-derived pathogens and donor tissue-derived cryptic infections. In this study, we aimed to produce surface modified therapeutic contact lenses for the culture and delivery of corneal epithelial cells for the treatment of LSCD. This approach avoids the possibility of suture-related complications and is completely synthetic. We used plasma polymerization to deposit acid functional groups onto the lenses at various concentrations. Each surface was tested for its suitability to promote corneal epithelial cell adhesion, proliferation, retention of stem cells, and differentiation and found that acid-based chemistries promoted better cell adhesion and proliferation. We also found that the lenses coated with a higher percentage of acid functional groups resulted in a higher number of cells transferred onto the corneal wound bed in rabbit models of LSCD. Immunohistochemistry of the recipient cornea confirmed the presence of autologous, transplanted 5-bromo-2'-deoxyuridine (BrdU)-labeled cells. Hematoxylin staining has also revealed the presence of a stratified epithelium at 26 days post-transplantation. This study provides the first evidence for in vivo transfer and survival of cells transplanted from a contact lens to the wounded corneal surface. It also proposes the possibility of using plasma polymer-coated contact lenses with high acid functional groups as substrates for the culture and transfer of limbal cells in the treatment of LSCD.

  5. Limbal Stromal Tissue Specific Stem Cells and Their Differentiation Potential to Corneal Epithelial Cells.

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    Katikireddy, Kishore Reddy; Jurkunas, Ula V

    2016-01-01

    From the derivation of the first human embryonic stem (hES) cell line to the development of induced pluripotent stem (iPS) cells; it has become evident that tissue specific stem cells are able to differentiate into a specific somatic cell types. The understanding of key processes such as the signaling pathways and the role of the microenvironment in epidermal/epithelial development has provided important clues for the derivation of specific epithelial cell types.Various differentiation protocols/methods were used to attain specific epithelial cell types. Here, we describe in detail the procedure to follow for isolation of tissue specific stem cells, mimicking their microenvironment to attain stem cell characteristics, and their potential differentiation to corneal epithelial cells.

  6. Lineage tracing in the adult mouse corneal epithelium supports the limbal epithelial stem cell hypothesis with intermittent periods of stem cell quiescence

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    Natalie J. Dorà

    2015-11-01

    Full Text Available The limbal epithelial stem cell (LESC hypothesis proposes that LESCs in the corneal limbus maintain the corneal epithelium both during normal homeostasis and wound repair. The alternative corneal epithelial stem cell (CESC hypothesis proposes that LESCs are only involved in wound repair and CESCs in the corneal epithelium itself maintain the corneal epithelium during normal homeostasis. We used tamoxifen-inducible, CreER-loxP lineage tracing to distinguish between these hypotheses. Clones of labelled cells were induced in adult CAGG-CreER;R26R-LacZ reporter mice and their distributions analysed after different chase periods. Short-lived clones, derived from labelled transient amplifying cells, were shed during the chase period and long-lived clones, derived from stem cells, expanded. At 6 weeks, labelled clones appeared at the periphery, extended centripetally as radial stripes and a few reached the centre by 14 weeks. Stripe numbers depended on the age of tamoxifen treatment. Stripes varied in length, some were discontinuous, few reached the centre and almost half had one end at the limbus. Similar stripes extended across the cornea in CAGG-CreER;R26R-mT/mG reporter mice. The distributions of labelled clones are inconsistent with the CESC hypothesis and support the LESC hypothesis if LESCs cycle between phases of activity and quiescence, each lasting several weeks.

  7. Generation of corneal epithelial cells from induced pluripotent stem cells derived from human dermal fibroblast and corneal limbal epithelium.

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    Ryuhei Hayashi

    Full Text Available Induced pluripotent stem (iPS cells can be established from somatic cells. However, there is currently no established strategy to generate corneal epithelial cells from iPS cells. In this study, we investigated whether corneal epithelial cells could be differentiated from iPS cells. We tested 2 distinct sources: human adult dermal fibroblast (HDF-derived iPS cells (253G1 and human adult corneal limbal epithelial cells (HLEC-derived iPS cells (L1B41. We first established iPS cells from HLEC by introducing the Yamanaka 4 factors. Corneal epithelial cells were successfully induced from the iPS cells by the stromal cell-derived inducing activity (SDIA differentiation method, as Pax6(+/K12(+ corneal epithelial colonies were observed after prolonged differentiation culture (12 weeks or later in both the L1B41 and 253G1 iPS cells following retinal pigment epithelial and lens cell induction. Interestingly, the corneal epithelial differentiation efficiency was higher in L1B41 than in 253G1. DNA methylation analysis revealed that a small proportion of differentially methylated regions still existed between L1B41 and 253G1 iPS cells even though no significant difference in methylation status was detected in the specific corneal epithelium-related genes such as K12, K3, and Pax6. The present study is the first to demonstrate a strategy for corneal epithelial cell differentiation from human iPS cells, and further suggests that the epigenomic status is associated with the propensity of iPS cells to differentiate into corneal epithelial cells.

  8. Optimization of optical and mechanical properties of real architecture for 3-dimensional tissue equivalents: Towards treatment of limbal epithelial stem cell deficiency.

    Science.gov (United States)

    Massie, Isobel; Kureshi, Alvena K; Schrader, Stefan; Shortt, Alex J; Daniels, Julie T

    2015-09-01

    Limbal epithelial stem cell (LESC) deficiency can cause blindness. Transplantation of cultured human limbal epithelial cells (hLE) on human amniotic membrane (HAM) can restore vision but clinical graft manufacture can be unreliable. We have developed a reliable and robust tissue equivalent (TE) alternative to HAM, Real Architecture for 3D Tissue (RAFT). Here, we aimed to optimize the optical and mechanical properties of RAFT TE for treatment of LESC deficiency in clinical application. The RAFT TE protocol is tunable; varying collagen concentration and volume produces differing RAFT TEs. These were compared with HAM samples taken from locations proximal and distal to the placental disc. Outcomes assessed were transparency, thickness, light transmission, tensile strength, ease of handling, degradation rates and suitability as substrate for hLE culture. Proximal HAM samples were thicker and stronger with poorer optical properties than distal HAM samples. RAFT TEs produced using higher amounts of collagen were thicker and stronger with poorer optical properties than those produced using lower amounts of collagen. The 'optimal' RAFT TE was thin, transparent but still handleable and was produced using 0.6ml of 3mg/ml collagen. Degradation rates of the 'optimal' RAFT TE and HAM were similar. hLE achieved confluency on 'optimal' RAFT TEs at comparable rates to HAM and cells expressed high levels of putative stem cell marker p63α. These findings support the use of RAFT TE for hLE transplantation towards treatment of LESC deficiency.

  9. In vitro passage and line establishment of human limbal stem cells%人角膜缘干细胞体外传代及建系

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    李舒梅; 罗晓婷; 文道源; 曾祥云; 陈水亲; 黄勤; 胡利群

    2007-01-01

    膜缘干细胞经体外培养33代并逐代冻存后初步建立了人角膜缘干细胞系,人角膜缘干细胞更适合在含有羊膜细胞外基质为底物的培养基中生长.%BACKGROUND: The investigation of culturing, passaging and establishing human limbal stem cells can strengthen the recognition of the stem cells and provide the enough cellular reserve for the basic and clinical research of limbal stem cell transplantation.OBJECTIVE: To explore a method of pessaging and establishing cell line of human limbal stem cells cultured in vitro.DESIGN: Randomized controlled observation.SETTING: Gannan Medical College.MATERIALS: The experiment was performed at Scientific Center of Gannan Medical College and the National Key Laboratory of Ophthalmology Hospital Affiliated to Sun Yat-Sen University from June 2003 to April 2004. Fresh human limbus corneae were isolated from two healthy donors. Procedures were performed according to the informed consent of the donors. Main reagents contained RPMI-1640 (Sigma R8755, containing L-glutamine) and 200 g/L fetal calf serum (FCS) (Gibco 16140-071). DMEM medium, chondroitin sulfatase and human epidermal growth factor (hEGF) were purchased from Sigma Co. USA; HEPES and DMSO were bought from Gibco, USA; 100% glycerinum was purchased from Yunjia Huangpu Pharmaceutical Product Limited Company, PRC; glutaraldehyde was bought from E.Merk, Germany; Alcohol, chlorhydric acid, acetone and methyl aldehyde were purchased from Beijing Chemical Agent Company, PRC; 0.25% parenzyme was bought from Shanghai Xinhua Pharmaceutical Factory, PRC.Above-mentioned reagents were analytical pure grade.METHODS: After digestion, human limbal tissues in limbal basilar part with an abundant pigment were cultured in the culture flask containing RPMI-1640 and 200 g/L FCS and in culture dish containing amniotic extracellular matrix (AECM) as the cultural supporter. Primary and passage cells were observed under light microscope and scanning electron

  10. Coculture of autologous limbal and conjunctival epithelial cells to treat severe ocular surface disorders: Long-term survival analysis

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    Sandhya V Subramaniam

    2013-01-01

    Full Text Available Background: Cultivated limbal epithelium for reconstruction of corneal surface is a well-established procedure; however, it is not adequate for damage which also extensively involves the conjunctiva. In severe cases of ocular surface damage that warrant additional conjunctival transplantation apart from cultivated limbal stem cell transplantation, we describe the long-term survival of a novel method of cocultivating autologous limbal and conjunctival epithelium on a single substrate. Materials and Methods: Forty eyes of 39 patients with severe limbal stem cell deficiency and conjunctival scarring or symblepharon underwent transplantation of autologous cocultivated epithelium on human amniotic membrane. A ring barrier was used to segregate the central limbal and peripheral conjunctival epithelia in vitro. Patients were followed up at regular intervals to assess stability of the ocular surface, defined by absence of conjunctivalization into the central 4 mm of the cornea and absence of diffuse fluorescein staining. Penetrating keratoplasty (PKP was subsequently performed, where indicated, in patients with surface stability. Results: The cumulative survival probability was 60% at 1 year and 45% at 4 years by Kaplan-Meier analysis (mean follow-up duration: 33 ± 29 months, range: 1-87 months. Best-corrected visual acuity improved to greater than 20/200 in 38% eyes at the last follow-up, compared with 5% eyes before surgery. Immunohistochemistry in five of the corneal buttons excised for PKP showed an epithelial phenotype similar to cornea in all five. Conclusions: Synchronous use of cultured limbal and conjunctival epithelium offers a feasible alternative and a simpler one-step surgical approach to treat severe ocular surface disorders involving limbus and conjunctiva.

  11. Moving epithelia: Tracking the fate of mammalian limbal epithelial stem cells.

    Science.gov (United States)

    Di Girolamo, Nick

    2015-09-01

    Lineage tracing allows the destiny of a stem cell (SC) and its progeny to be followed through time. In order to track their long-term fate, SC must be permanently marked to discern their distribution, division, displacement and differentiation. This information is essential for unravelling the mysteries that govern their replenishing activity while they remain anchored within their niche microenvironment. Modern-day lineage tracing uses inducible genetic recombination to illuminate cells within embryonic, newborn and adult tissues, and the advent of powerful high-resolution microscopy has enabled the behaviour of labelled cells to be monitored in real-time in a living organism. The simple structural organization of the mammalian cornea, including its accessibility and transparency, renders it the ideal tissue to study SC fate using lineage tracing assisted by non-invasive intravital microscopy. Despite more than a century of research devoted to understanding how this tissue is maintained and repaired, many limitations and controversies continue to plague the field, including uncertainties about the specificity of current SC markers, the number of SC within the cornea, their mode of division, their location, and importantly the signals that dictate cell migration. This communication will highlight historical discoveries as well as recent developments in the corneal SC field; more specifically how the progeny of these cells are mobilised to replenish this dynamic tissue during steady-state, disease and transplantation. Also discussed is how insights gleaned from animal studies can be used to advance our knowledge of the fundamental mechanisms that govern modelling and remodelling of the human cornea in health and disease.

  12. Adenoviral Gene Therapy for Diabetic Keratopathy: Effects on Wound Healing and Stem Cell Marker Expression in Human Organ-cultured Corneas and Limbal Epithelial Cells.

    Science.gov (United States)

    Kramerov, Andrei A; Saghizadeh, Mehrnoosh; Ljubimov, Alexander V

    2016-04-07

    The goal of this protocol is to describe molecular alterations in human diabetic corneas and demonstrate how they can be alleviated by adenoviral gene therapy in organ-cultured corneas. The diabetic corneal disease is a complication of diabetes with frequent abnormalities of corneal nerves and epithelial wound healing. We have also documented significantly altered expression of several putative epithelial stem cell markers in human diabetic corneas. To alleviate these changes, adenoviral gene therapy was successfully implemented using the upregulation of c-met proto-oncogene expression and/or the downregulation of proteinases matrix metalloproteinase-10 (MMP-10) and cathepsin F. This therapy accelerated wound healing in diabetic corneas even when only the limbal stem cell compartment was transduced. The best results were obtained with combined treatment. For possible patient transplantation of normalized stem cells, an example is also presented of the optimization of gene transduction in stem cell-enriched cultures using polycationic enhancers. This approach may be useful not only for the selected genes but also for the other mediators of corneal epithelial wound healing and stem cell function.

  13. Laser scanning confocal microscopy-assisted obtain of limbal tissue for the ex vivo culture of human limbal epithelial stem cells and identification%共焦显微镜引导下取材行人角膜缘上皮干细胞的体外培养及鉴定

    Institute of Scientific and Technical Information of China (English)

    杜连心; 余晓菲; 许中中; 张红敏; 杜晓峰; 王丽娅

    2011-01-01

    Background Human limbal allograft transplantation or limbal autograft transplantation are the primary approaches to the severe corneal-blindness,but their application in clinic were limited because of the defects of donor material.With the development of tissue engineering technology,transplantation of in vitro cultured limbal epithelial stem cells is being an advanced management.Objective The aim of this work was to expand human limbal epithelial stem cells ex vivo under the guidance of confocal microscope and to lay the foundation for fabricating ex vivo cultured cell sheets.Methods Ten eyes of ten patients were examined with the Heidelberg Retina Tomography Ⅲ Rostock Cornea Module(HRT3-RCM)to elucidate the structure of the human corneoscleral limbus and to correlate limbal epithelial dimensions.According to the analysis of the images of limbal epithelia,the limbal tissues provided by Eye Bank of Henan Eye Institute were cut into suitable explants.Then,this study was conducted to expand limbal epithelial stem cells ex vivo on denuded amniotic membrane.The phenotypes of primary cultured cells were evaluated by morphology and immunofluorescent staining with antibodies for limbal epithelial stem cell markers (p63,cytokeratinl9)and differentiation markers(keratin 3,involucrin).This experimental procedure was approved by the Ethic Committee of Henan Provincial People's Hospital.The written informed consent was obtained from subjects before initiation of any examination.Results The palisade morphology of human limbus was imaged clearly on the laser scanning in vivo confocal microscopy and many hyperreflective cells were observed in palisade basal cells.The cell-island phenomenon was seen in the basement membrane under the laser scanning in vivo confocal microscopy.The oblique sections of limbus showed many papilla-like epithelial columns below the superficial limbal epithelia.Throughout the experiment duration,the epithelial cells grew well with the migration rates

  14. An important role for adenine, cholera toxin, hydrocortisone and triiodothyronine in the proliferation, self-renewal and differentiation of limbal stem cells in vitro.

    Science.gov (United States)

    Yu, Min; Bojic, Sanja; Figueiredo, Gustavo S; Rooney, Paul; de Havilland, Julian; Dickinson, Anne; Figueiredo, Francisco C; Lako, Majlinda

    2016-11-01

    The cornea is a self-renewing tissue located at the front of the eye. Its transparency is essential for allowing light to focus onto the retina for visual perception. The continuous renewal of corneal epithelium is supported by limbal stem cells (LSCs) which are located in the border region between conjunctiva and cornea known as the limbus. Ex vivo expansion of LSCs has been successfully applied in the last two decades to treat patients with limbal stem cell deficiency (LSCD). Various methods have been used for their expansion, yet the most widely used culture media contains a number of ingredients derived from animal sources which may compromise the safety profile of human LSC transplantation. In this study we sought to understand the role of these components namely adenine, cholera toxin, hydrocortisone and triiodothyronine with the aim of re-defining a safe and GMP compatible minimal media for the ex vivo expansion of LSCs on human amniotic membrane. Our data suggest that all four components play a critical role in maintaining LSC proliferation and promoting LSC self-renewal. However removal of adenine and triiodothyronine had a more profound impact and led to LSC differentiation and loss of viability respectively, suggesting their essential role for ex vivo expansion of LSCs. Replacement of each of the components with GMP-grade reagents resulted in equal growth to non-GMP grade media, however an enhanced differentiation of LSCs was observed, suggesting that additional combinations of GMP grade reagents need to be tested to achieve similar or better level of LSC maintenance in the same manner as the traditional LSC media.

  15. Variations in the technique for autologous limbal transplantation.

    Science.gov (United States)

    Mataix, B; Alcántara, A; Caro, M; Montero, J; Ponte, B; Rodríguez de la Rúa, E

    2016-10-01

    To present the results on the use of a single block limbal autograft, combined with amniotic membrane transplantation and sectoral sequential postoperative epitheliectomy of the conjunctiva in 2 patients with unilateral total limbal stem cell deficiency. A single block limbal autograft combined with amniotic membrane transplantation may be sufficient to restore a stable corneal surface, but sometimes sequential sectoral conjunctival epitheliectomy may be required to treat anomalous epithelial remnants. Copyright © 2016 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

  16. Living related conjunctival limbal allograft and amniotic membrane transplantation for limbal stem cell deficiency in chemically injured eyes%活体异体结膜缘和羊膜移植治疗化学性眼外伤造成的角膜缘干细胞缺失

    Institute of Scientific and Technical Information of China (English)

    Mehdi Hosseini Tehrani; Asoo Ali Mahmoudi; Hassan Hashemi; Syed Jafar Oskouee; Javad Amuzadeh; Mohammad Taher Rajabi; Masoomeh Taherzadeh; Hamideh Shenazandi

    2008-01-01

    目的:评价利用活体异体结膜缘和羊膜移植治疗化学性眼外伤造成的角膜缘干细胞缺失的临床效果.方法:从2005-07/2007-12,本研究包括了9名男性化学性眼外伤患者(10眼).所有患者接受了亲属活体异体结膜缘和羊膜移植,2例眼接受了睑缝术.用环孢菌素和泼尼松龙进行全身性免疫抑制.结果:在3例眼中观察到完全角膜上皮化(30%),其中1例在术后1.5mo出现免疫排斥,角膜溶解引起穿孔,加大全身性免疫抑制剂量来控制病情.3例眼中植片无法在角膜表面重新形成上皮,被定为原发性失败.其余4眼有部分上皮形成,但上皮细胞无法完全覆盖角膜表面.术前最佳矫正视力从手动到1m处数指,术后最佳矫正视力从光感到20/80.有5眼视力得到改进,不需其他治疗.手术失败的主要原因为干眼症和持续性炎症.结论:对于能控制泪量和眼部炎症的病例,亲属活体异体角膜缘和羊膜移植是治疗化学性眼外伤造成的角膜缘干细胞缺失最佳方法之一.%AIM: To evaluate the clinical success of living related conjunctival limbal and amniotic membrane transplantation for treatment of chemical injury induced limbal stem cell deficiency.METHODS: From July 2005 to December 2007, 10 eyes of 9 male patients with chemical injury induced limbal stem cell deficiency were included in the study. All subjects underwent living related conjunctival limbal and amniotic membrane transplantation. Blepharorrhaphy was performed in two cases. Systemic immunosuppression with cyclosporine and prednisolone was initiated.RESULTS: Complete corneal epithelialization was observed in 3 eyes (30%). In one of the patients immunologic rejection and corneal melting led to perforation 1.5 months after surgery. The increasing dose of systemic immunosuppression was used to control it. Three eyes were described as primary failure because graft could not re-epithelialize the corneal surface. The remained four

  17. Parasitism of Lepidopterous Stem Borers in Cultivated and Natural Habitats

    Science.gov (United States)

    Mailafiya, Duna Madu; Le Ru, Bruno Pierre; Kairu, Eunice Waitherero; Dupas, Stéphane; Calatayud, Paul-André

    2011-01-01

    Plant infestation, stem borer density, parasitism, and parasitoid abundance were assessed during two years in two host plants, Zea mays (L.) (Cyperales: Poaceae) and Sorghum bicolor (L.) (Cyperales: Poaceae), in cultivated habitats. The four major host plants (Cyperus spp., Panicum spp., Pennisetum spp., and Sorghum spp.) found in natural habitats were also assessed, and both the cultivated and natural habitat species occurred in four agroecological zones in Kenya. Across habitats, plant infestation (23.2%), stem borer density (2.2 per plant), and larval parasitism (15.0%) were highest in maize in cultivated habitats. Pupal parasitism was not higher than 4.7% in both habitats, and did not vary with locality during each season or with host plant between each season. Cotesia sesamiae (Cameron) and C. flavipes Cameron (Hymenoptera: Braconidae) were the key parasitoids in cultivated habitats (both species accounted for 76.4% of parasitized stem borers in cereal crops), but not in natural habitats (the two Cotesia species accounted for 14.5% of parasitized stem borers in wild host plants). No single parasitoid species exerted high parasitism rates on stem borer populations in wild host plants. Low stem borer densities across seasons in natural habitats indicate that cereal stem borer pests do not necessarily survive the non-cropping season feeding actively in wild host plants. Although natural habitats provided refuges for some parasitoid species, stem borer parasitism was generally low in wild host plants. Overall, because parasitoids contribute little in reducing cereal stem borer pest populations in cultivated habitats, there is need to further enhance their effectiveness in the field to regulate these pests. PMID:21526933

  18. Parasitism of lepidopterous stem borers in cultivated and natural habitats.

    Science.gov (United States)

    Mailafiya, Duna Madu; Le Ru, Bruno Pierre; Kairu, Eunice Waitherero; Dupas, Stéphane; Calatayud, Paul-André

    2011-01-01

    Plant infestation, stem borer density, parasitism, and parasitoid abundance were assessed during two years in two host plants, Zea mays (L.) (Cyperales: Poaceae) and Sorghum bicolor (L.) (Cyperales: Poaceae), in cultivated habitats. The four major host plants (Cyperus spp., Panicum spp., Pennisetum spp., and Sorghum spp.) found in natural habitats were also assessed, and both the cultivated and natural habitat species occurred in four agroecological zones in Kenya. Across habitats, plant infestation (23.2%), stem borer density (2.2 per plant), and larval parasitism (15.0%) were highest in maize in cultivated habitats. Pupal parasitism was not higher than 4.7% in both habitats, and did not vary with locality during each season or with host plant between each season. Cotesia sesamiae (Cameron) and C. flavipes Cameron (Hymenoptera: Braconidae) were the key parasitoids in cultivated habitats (both species accounted for 76.4% of parasitized stem borers in cereal crops), but not in natural habitats (the two Cotesia species accounted for 14.5% of parasitized stem borers in wild host plants). No single parasitoid species exerted high parasitism rates on stem borer populations in wild host plants. Low stem borer densities across seasons in natural habitats indicate that cereal stem borer pests do not necessarily survive the non-cropping season feeding actively in wild host plants. Although natural habitats provided refuges for some parasitoid species, stem borer parasitism was generally low in wild host plants. Overall, because parasitoids contribute little in reducing cereal stem borer pest populations in cultivated habitats, there is need to further enhance their effectiveness in the field to regulate these pests.

  19. Long-Term Cultures of Human Cornea Limbal Explants Form 3D Structures Ex Vivo - Implications for Tissue Engineering and Clinical Applications.

    Science.gov (United States)

    Szabó, Dóra Júlia; Noer, Agate; Nagymihály, Richárd; Josifovska, Natasha; Andjelic, Sofija; Veréb, Zoltán; Facskó, Andrea; Moe, Morten C; Petrovski, Goran

    2015-01-01

    Long-term cultures of cornea limbal epithelial stem cells (LESCs) were developed and characterized for future tissue engineering and clinical applications. The limbal tissue explants were cultivated and expanded for more than 3 months in medium containing serum as the only growth supplement and without use of scaffolds. Viable 3D cell outgrowth from the explants was observed within 4 weeks of cultivation. The outgrowing cells were examined by immunofluorescent staining for putative markers of stemness (ABCG2, CK15, CK19 and Vimentin), proliferation (p63α, Ki-67), limbal basal epithelial cells (CK8/18) and differentiated cornea epithelial cells (CK3 and CK12). Morphological and immunostaining analyses revealed that long-term culturing can form stratified 3D tissue layers with a clear extracellular matrix deposition and organization (collagen I, IV and V). The LESCs showed robust expression of p63α, ABCG2, and their surface marker fingerprint (CD117/c-kit, CXCR4, CD146/MCAM, CD166/ALCAM) changed over time compared to short-term LESC cultures. Overall, we provide a model for generating stem cell-rich, long-standing 3D cultures from LESCs which can be used for further research purposes and clinical transplantation.

  20. Meta-analysis of limbal stem cell transplantation and amniotic membrane transplantation for pterygium%角膜缘干细胞移植与羊膜移植治疗翼状胬肉的Meta分析

    Institute of Scientific and Technical Information of China (English)

    于晓明; 吴欣怡

    2013-01-01

    Objective To evaluate the clinical effect of limbal stem cell transplantation and amniotic membrane transplantation in the treatment of pterygium by evidence based medicine. Methods Clinical data of effect in limbal stem cell transplantation and amniotic membrane transplantation were collected from computer literature searching, which was carried out in PubMed, EMBASE, Wanfang and VIP database etc, also performed searching based on www. baidu. com and www. google. com. Meta analysis that recommended by Cochrane Collaboration was done for the data obtained that 3 126 eyes that met with the eleven criteria of enrollment were included in this study. Publication bias was assessed by using a funnel plot. Results The results of meta-analysis showed that 35 RCTs evaluated the pterygium recurrent rate after grafting including 3 126 eyes, the incidence rate including 1 108 eyes, and the mean time of corneal epithelium wound healing including 900 eyes. In comparison with the amniotic membrane transplantation group, the recurrent rates of pterygium (P < 0.000 01) and the total complication rate (P = 0.01) were lower in the limbal stem cell transplantation group. Moreover , the mean time of corneal epithelium wound healing was shorter in the limbal stem cell transplantation group. Conclusion Corneal limbal stem cell autograft is an effective way to reduce the recurrent rate of pterygium and the incidence of symblepharon and to accelerate the healing of corneal wound comparing with amniotic membrane transplantation.%目的 以循证医学证据评价角膜缘干细胞移植和羊膜移植治疗翼状胬肉的临床疗效.方法 通过计算机检索Pubmed数据库、EMBASE、万方数据库、中国期刊全文数据库和维普数据库,并结合文献追溯的方法,收集关于角膜缘干细胞移植和羊膜移植治疗翼状胬肉临床疗效的随机前瞻性对照试验(RCT),并按Cochrane协作网推荐的方法对符合纳入标准的35个研究,共3 126只眼进

  1. Y-27632, a ROCK Inhibitor, Promoted Limbal Epithelial Cell Proliferation and Corneal Wound Healing.

    Directory of Open Access Journals (Sweden)

    Chi-Chin Sun

    Full Text Available Transplantation of ex vivo cultured limbal epithelial cells is proven effective in restoring limbal stem cell deficiency. The present study aimed to investigate the promoting effect of Y-27632 on limbal epithelial cell proliferation. Limbal explants isolated from human donor eyes were expanded three weeks on culture dishes and outgrowth of epithelial cells was subsequently subcultured for in vitro experiments. In the presence of Y-27632, the ex vivo limbal outgrowth was accelerated, particularly the cells with epithelial cell-like morphology. Y-27632 dose-dependently promoted the proliferation of in vitro cultured human limbal epithelial cells as examined by phase contrast microscopy and luminescent cell-viability assay 30 hours after the treatment. The colony forming efficacy determined 7 days after the treatment was enhanced by Y-27632 also in a dose-dependent manner. The number of p63- or Ki67-positive cells was dose-dependently increased in Y-27632-treated cultures as detected by immunofluorescent staining and western blotanalysis. Cell cycle analysis by flow cytometric method revealed an increase in S-phase proliferating cells. The epithelial woundclosure rate was shown to be faster in experimental group received topical treatment withY-27632 than the sham control using a rat corneal wounding model. These resultsdemonstrate that Y-27632 can promote both the ex vivo and in vitro proliferation oflimbal epithelial cell proliferation. The in vivo enhanced epithelial wound healingfurther implies that the Y-27632 may act as a new strategy for treating limbal stem cell deficiency.

  2. Minor ipsilateral simple limbal epithelial transplantation (mini-SLET) for pterygium treatment

    Science.gov (United States)

    Hernández-Bogantes, Erick; Amescua, Guillermo; Navas, Alejandro; Garfias, Yonathan; Ramirez-Miranda, Arturo; Lichtinger, Alejandro; Graue-Hernández, Enrique O

    2015-01-01

    We describe a novel surgical technique for pterygium removal taking advantage of the properties of amniotic membrane and limbal epithelial stem cells. A total of 10 eyes underwent pterygium excision with amniotic membrane coverage of the bare sclera and placement of pieces of limbal epithelium in a linear fashion in the affected limbal area covered by a second amniotic membrane using fibrin glue. After up to 8 months of follow-up, there were no signs of early recurrence or sight-threatening complications. The minor ipsilateral simple limbal epithelial transplantation technique for the treatment of pterygium requires less tissue than the conventional conjunctival autograft, leaving healthy conjunctiva if needed for another procedure in the future and offers the advantages of epithelial stem cells, which in the long term may reduce the rate of recurrence significantly. PMID:26130669

  3. Limbal stem cell transplantation combined with mitomycin treatment of recurrent pterygium%自体角膜缘干细胞移植联合丝裂霉素治疗复发性翼状胬肉疗效观察

    Institute of Scientific and Technical Information of China (English)

    梁艳丽

    2014-01-01

    目的:观察自体角膜缘干细胞移植联合丝裂霉素治疗复发性翼状胬肉手术疗效。方法对22只眼复发性翼状胬肉进行自体角膜缘干细胞移植联合丝裂霉素治疗。结果22例随访6~12月,平均16.5月。无1例复发,未发现睑球粘连者。结论自体角膜缘干细胞移植联合丝裂霉素治疗复发性翼状胬肉,方法简单,取材方便,无排斥反应,是治疗翼状胬肉的有效方法。%Objective to observe the limbal stem cell transplantation combined with mitomycin treatment of recurrent pterygium surgery. Methods 22 eyes with recurrent pterygium autologous limbal stem cell transplantation combined with mitomycin c treatment. Results 22 cases followed up for 6 to 12 months, an average of 16.5 months. no recurrence was not found symblepharon. Conclusion limbal stem cell transplantation combined with mitomycin treatment of recurrent pterygium, simple, easily obtained, no rejection is an effective method of treatment of pterygium.

  4. Expansion of mesenchymal stem cells using a microcarrier-based cultivation system: growth and metabolism

    NARCIS (Netherlands)

    Schop, D.; Janssen, F.W.; Borgart, E.; Bruijn, de J.D.; Dijkhuizen-Radersma, van R.

    2008-01-01

    For the continuous and fast expansion of mesenchymal stem cells (MSCs), microcarriers have gained increasing interest. The aim of this study was to evaluate the growth and metabolism profiles of MSCs, expanded in a microcarrier-based cultivation system. We investigated various cultivation conditions

  5. Factors affecting stem borer parasitoid species diversity and parasitism in cultivated and natural habitats.

    Science.gov (United States)

    Mailafiya, Duna Madu; Le Ru, Bruno Pierre; Kairu, Eunice Waitherero; Calatayud, Paul-André; Dupas, Stéphane

    2010-02-01

    The effects of biotic and abiotic factors on stem borer parasitoid diversity, abundance, and parasitism were studied in cultivated and natural habitats in four agroecological zones in Kenya. Comparing habitat types, we found partial support for the "natural enemy" hypothesis, whereby, across all localities, parasitoid diversity was higher in more diverse host plant communities in natural habitats, whereas parasitoid abundance was higher in cultivated habitats. For both habitats, parasitoid richness was mainly influenced by stem borer density and/or its interaction with stem borer richness, whereas parasitoid abundance was mainly affected by stem borer abundance. Parasitoid richness was higher in localities (with bimodal rainfall distribution) with increased spatial and temporal availability of host plants that harbored the borers. Across seasons, parasitoid richness was lower in both cultivated and natural habitats in the driest locality, Mtito Andei. Overall, parasitoid diversity was low in Suam and Mtito Andei, where maize cultivation was practiced on a commercial scale and intense grazing activities persist across seasons, respectively. Across localities, habitats, and seasons, stem borer parasitism was positively correlated with parasitoid richness and abundance. Furthermore, the interaction of rainfall and altitude influenced the presence and absence of parasitoids, and consequently, stem borer parasitism. Parasitism was positively and negatively correlated with temperature in cultivated and natural habitats, respectively. Overall, natural habitats seem to serve as important refugia for sustaining parasitoid diversity, which in turn can affect stem borer parasitism in the cereal cropping system.

  6. Presence of bilateral limbal dermoids and choroidal osteomas in a family with inherited limbal dermoids.

    Science.gov (United States)

    Magli, A; De Marco, R; Capasso, L

    1999-06-01

    We report a case of bilateral limbal dermoids and bilateral choroidal osteomas in a 14-year-old girl with no extraocular anomalies. Histopathological examination of a limbal lesion confirmed the clinical diagnosis of dermoid. Computerized tomography and ultrasonography were compatible with a diagnosis of choroidal osteoma. Limbal dermoids were present in the patient's mother, in a brother with Down syndrome, and in an aunt with no choroidal osteoma. The present pedigree is compatible with autosomal dominant inheritance of bilateral limbal dermoids. The same gene may be involved in the pathogenesis of ocular choristomas in same patients.

  7. An investigation of donor and culture parameters which influence epithelial outgrowths from cultured human cadaveric limbal explants.

    Science.gov (United States)

    Baylis, Oliver; Rooney, Paul; Figueiredo, Francisco; Lako, Majlinda; Ahmad, Sajjad

    2013-05-01

    Limbal stem cell deficiency is a blinding disease which affects the cornea at the front of the eye. The definitive cure involves replacing the corneal epithelial (limbal) stem cells, for example by transplanting cultured limbal epithelial cells. One method of performing cultures is to grow a sheet of epithelial cells from a limbal explant on human amniotic membrane. The growth of limbal tissue can be variable. The aim of this study is to investigate how different donor and culture factors influence the ex vivo growth of cadaveric limbal explants. Limbal explant cultures were established from 10 different cadaveric organ cultured corneo-scleral discs. The growth rate and the time taken for growth to be established were determined. Statistical analysis was performed to assess correlation between these factors and donor variables including donor age, sex, time from donor death to enucleation, time from enucleation to organ culture storage and duration in organ culture. Growth curves consistently showed a lag phase followed by a steeper linear growth phase. Donor age, time between death and enucleation, and time between enucleation and organ culture were not correlated to the lag time or the growth rate. Time in organ culture had a significant correlation with the duration of lag time (P = 0.003), but no relationship with the linear growth rate. This study shows that an important factor correlating with growth variation is the duration of corneo-scleral tissue in organ culture. Interestingly, donor age was not correlated with limbal explant growth. Copyright © 2012 Wiley Periodicals, Inc.

  8. Growth and metabolism of mesenchymal stem cells cultivated on microcarriers

    NARCIS (Netherlands)

    Schop, Deborah

    2010-01-01

    Mesenchymal stem cells, MSCs, are a great potential source for clinical applications in the field of tissue regeneration. Although MSCs can be isolated from several tissues of the human body, e.g. the bone marrow, the tissues does not contain clinically relevant amounts of MSCs for cell therapeutic

  9. Improved Method for Ex Ovo-Cultivation of Developing Chicken Embryos for Human Stem Cell Xenografts

    Directory of Open Access Journals (Sweden)

    Timo Schomann

    2013-01-01

    Full Text Available The characterization of human stem cells for the usability in regenerative medicine is particularly based on investigations regarding their differentiation potential in vivo. In this regard, the chicken embryo model represents an ideal model organism. However, the access to the chicken embryo is only achievable by windowing the eggshell resulting in limited visibility and accessibility in subsequent experiments. On the contrary, ex ovo-culture systems avoid such negative side effects. Here, we present an improved ex ovo-cultivation method enabling the embryos to survive 13 days in vitro. Optimized cultivation of chicken embryos resulted in a normal development regarding their size and weight. Our ex ovo-approach closely resembles the development of chicken embryos in ovo, as demonstrated by properly developed nervous system, bones, and cartilage at expected time points. Finally, we investigated the usability of our method for trans-species transplantation of adult stem cells by injecting human neural crest-derived stem cells into late Hamburger and Hamilton stages (HH26–HH28/E5—E6 of ex ovo-incubated embryos. We demonstrated the integration of human cells allowing experimentally easy investigation of the differentiation potential in the proper developmental context. Taken together, this ex ovo-method supports the prolonged cultivation of properly developing chicken embryos enabling integration studies of xenografted mammalian stem cells at late developmental stages.

  10. Transplante de membrana amniótica canina criopreservada para cicatrização de córnea com deficiência de células límbicas em coelhos Transplantation of cryopreserved canine amniotic membrane for cicatrisation in cornea with limbal stem cells deficiency in rabbits

    Directory of Open Access Journals (Sweden)

    D.N. Cremonini

    2007-12-01

    Full Text Available Avaliaram-se as alterações relacionadas à deficiência das células límbicas precursoras do epitélio corneano de coelhos e o efeito da membrana amniótica sobre sua cicatrização. A lesão, induzida com n-heptanol associado à peritomia conjuntival em 360°, foi recoberta com membrana amniótica canina, suturada à episclera perilímbica, criopreservada em meio para congelação de embrião ou em meio próprio, ambos com glicerol a 50% e mantida a -80°C. O grupo-controle não foi tratado com a membrana. As avaliações histológicas foram realizadas ao sétimo, 15º e 30º dias. Todos desenvolveram deficiência de células germinativas do limbo, denominada conjuntivalização, com presença de neovascularização, inflamação e defeitos epiteliais recorrentes, caracterizada na histopatologia pela presença de neovasos, edema, leucócitos e células caliciformes. O transplante de membrana amniótica não foi eficiente para o tratamento desta deficiência, entretanto auxiliou o processo de cicatrização da córnea.Changes related to limbal stem cells deficiency in corneal epithelium in rabbits, as well as the results of amniotic membrane transplant on the cicatrisation were evaluated. The ulcer was induced with n-heptanol associated to 360° conjunctival peritomy; the corneal surface was covered with canine amniotic membrane, sutured to perilimbal episclera, cryopreserved in embryo solution or own medium, both with 50% glycerol and stored at -80°C. The control group was not treated with membrane. Histological evaluations were performed at seven, 15, and 30 days. All of them developed limbal stem cells deficiency, named conjunctivalization, with neovascularization, inflammation and recurrent epithelial defects, observed in histopathology by the occurrence of neovascularization, edema, leukocytes and goblet cells. Thus amniotic membrane transplantation was not efficient in the treatment of limbal stem cells deficiency, however it helped in

  11. Cultivation and differentiation change nuclear localization of chromosome centromeres in human mesenchymal stem cells.

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    Yana I Voldgorn

    Full Text Available Chromosome arrangement in the interphase nucleus is not accidental. Strong evidences support that nuclear localization is an important mechanism of epigenetic regulation of gene expression. The purpose of this research was to identify differences in the localization of centromeres of chromosomes 6, 12, 18 and X in human mesenchymal stem cells depending on differentiation and cultivating time. We analyzed centromere positions in more than 4000 nuclei in 19 mesenchymal stem cell cultures before and after prolonged cultivation and after differentiation into osteogenic and adipogenic directions. We found a centromere reposition of HSAX at late passages and after differentiation in osteogenic direction as well as of HSA12 and HSA18 after adipogenic differentiation. The observed changes of the nuclear structure are new nuclear characteristics of the studied cells which may reflect regulatory changes of gene expression during the studied processes.

  12. Cultivation and differentiation change nuclear localization of chromosome centromeres in human mesenchymal stem cells.

    Science.gov (United States)

    Voldgorn, Yana I; Adilgereeva, Elmira P; Nekrasov, Evgeny D; Lavrov, Alexander V

    2015-01-01

    Chromosome arrangement in the interphase nucleus is not accidental. Strong evidences support that nuclear localization is an important mechanism of epigenetic regulation of gene expression. The purpose of this research was to identify differences in the localization of centromeres of chromosomes 6, 12, 18 and X in human mesenchymal stem cells depending on differentiation and cultivating time. We analyzed centromere positions in more than 4000 nuclei in 19 mesenchymal stem cell cultures before and after prolonged cultivation and after differentiation into osteogenic and adipogenic directions. We found a centromere reposition of HSAX at late passages and after differentiation in osteogenic direction as well as of HSA12 and HSA18 after adipogenic differentiation. The observed changes of the nuclear structure are new nuclear characteristics of the studied cells which may reflect regulatory changes of gene expression during the studied processes.

  13. The potential of dental stem cells differentiating into neurogenic cell lineage after cultivation in different modes in vitro.

    Science.gov (United States)

    Yang, Chao; Sun, Liang; Li, Xinghan; Xie, Li; Yu, Mei; Feng, Lian; Jiang, Zongting; Guo, Weihua; Tian, Weidong

    2014-10-01

    Trauma or degenerative diseases of the central nervous system (CNS) cause the loss of neurons or glial cells. Stem cell transplantation has become a vital strategy for CNS regeneration. It is necessary to effectively induce nonneurogenic stem cells to differentiate into neurogenic cell lineages because of the limited source of neurogenic stem cells, relatively difficult cultivation, and ethical issues. Previous studies have found that dental stem cells can be used for transplantation therapy. The aim of this study was to explore a better inductive mode and time point for dental stem cells to differentiate into neural-like cells and evaluate a better candidate cell. In this study, dental follicle stem cells (DFSCs), dental papilla stem cells (DPSCs), and stem cells from apical papilla (SCAPs) were cultivated in five different modes. The proliferation ability, morphology, and expression of neural marker genes were analyzed. Results showed that DFSCs showed a higher proliferation potential. The proliferation was decreased after cultivation in chemical inductive medium as cultivation modes 3 and 5. The cells could present neural-like cell morphology after cultivation with human epidermal growth factor (EGF) and fibroblast growth factor-basic (bFGF) as cultivation modes 4 and 5. The vast majority of DFSCs gene expression levels in mode 4 on the third day was upregulated significantly. In conclusion, our data suggested that different dental stem cells exhibited different neural differentiation potentials. DFSCs might be the better candidate cell type. Furthermore, cultivation mode 4 and timing of the third day may promote differentiation into neurogenic cell lineages more effectively before transplantation to treat neurological diseases.

  14. Impact of irrigation on larval density of stem-infesting pests of cultivated sunflower in Kansas.

    Science.gov (United States)

    Charlet, Laurence D; Aiken, Robert M; Meyer, Ron F; Gebre-Amlak, Assefa

    2007-10-01

    The guild of stem-infesting insect pests of cultivated sunflower, Helianthus annuus L., within the central Plains is a concern to producers, chiefly due to losses caused by plant lodging from the sunflower stem weevil, Cylindrocopturus adspersus (LeConte) (Coleoptera: Curculionidae), and Dectes texanus texanus LeConte (Coleoptera: Cerambycidae). The incidence of a root boring moth, Pelochrista womonana (Kearfott) (Lepidoptera: Tortricidae), also has increased. Experiments were conducted in Kansas during 2000-2001 to investigate the effect of irrigation timing and intensity on densities of C. adspersus, D. texanus, and P. womonana larvae within cultivated sunflower stalks. Supplemental soil moisture provided by irrigation during the growing season increased both seed yield and oil content, and it reduced insect densities of the sunflower stem weevil and P. womonana in the sunflower stalk. Results showed that ensuring adequate moisture during the growing season can assist in reducing stem-infesting insect densities, revealing an additional advantage of crop irrigation beyond improved sunflower productivity.

  15. Porcine EPCs downregulate stem cell markers and upregulate endothelial maturation markers during in vitro cultivation.

    Science.gov (United States)

    Avci-Adali, Meltem; Nolte, Andrea; Simon, Perikles; Ziemer, Gerhard; Wendel, Hans P

    2009-10-01

    In recent years, interest in endothelial progenitor cells (EPCs) in the field of tissue engineering and regenerative medicine has increased tremendously. However, each clinical stem cell application requires prior validation through animal experiments. This study investigates the isolation and characterization of porcine EPCs from peripheral blood and the change of their cell surface marker expression during in vitro cultivation. RT-PCR demonstrated that the EPCs express stem cell markers CD34 and CD133, which decrease with in vitro cultivation time. Throughout the cultivation process EPCs did not express monocytic (CD14) or haematopoietic marker (CD45). Surprisingly, the CD31 and VE-cadherin expression in EPCs was significantly higher than in endothelial cells (ECs). In contrast, the VEGFR2 and E-selectin expression was significantly lower than in ECs, but increased during the expansion process. This study clarifies the characteristic properties of porcine EPCs during cell culture and may help to improve the impact of EPC-based therapies in porcine animal studies.

  16. Ultra-structural morphology of long-term cultivated white adipose tissue-derived stem cells.

    Science.gov (United States)

    Varga, Ivan; Miko, Michal; Oravcová, Lenka; Bačkayová, Tatiana; Koller, Ján; Danišovič, Ľuboš

    2015-12-01

    White adipose tissue was long perceived as a passive lipid storage depot but it is now considered as an active and important endocrine organ. It also harbours not only adipocytes and vascular cells but also a wide array of immunologically active cells, including macrophages and lymphocytes, which may induce obesity-related inflammation. Recently, adipose tissue has been reported as a source of adult mesenchymal stem cells with wide use in regenerative medicine and tissue engineering. Their relatively non-complicated procurement and collection (often performed as liposuction during aesthetic surgery) and grand plasticity support this idea even more. We focused our research on exploring the issues of isolation and long-term cultivation of mesenchymal stem cells obtained from adipose tissue. Ultra-structural morphology of the cells cultivated in vitro has been studied and analysed in several cultivation time periods and following serial passages--up to 30 passages. In the first passages they had ultra-structural characteristics of cells with high proteosynthetic activity. Within the cytoplasm, big number of small lipid droplets and between them, sparsely placed, small and inconspicuous, electron-dense, lamellar bodies, which resembled myelin figures were observed. The cells from the later passages contained high number of lamellar electron-dense structures, which filled out almost the entire cytoplasm. In between, mitochondria were often found. These bodies were sometimes small and resembled myelin figures, but several of them reached huge dimensions (more than 1 µm) and their lamellar structure was not distinguishable. We did not have an answer to the question about their function, but they probably represented the evidence of active metabolism of lipids present in the cytoplasm of these cells or represented residual bodies, which arise after the breakdown of cellular organelles, notably mitochondria during long-term cultivation.

  17. Autologous method for ex vivo expansion of human limbal epithelial progenitor cells based on plasma rich in growth factors technology.

    Science.gov (United States)

    Riestra, A C; Vazquez, N; Chacon, M; Berisa, S; Sanchez-Avila, R M; Orive, G; Anitua, E; Meana, A; Merayo-Lloves, J

    2017-04-01

    Develop an autologous culture method for ex vivo expansion of human limbal epithelial progenitor cells (LEPCs) using Plasma Rich in Growth Factors (PRGF) as a growth supplement and as a scaffold for the culture of LEPCs. LEPCs were cultivated in different media supplemented with 10% fetal bovine serum (FBS) or 10% PRGF. The outgrowths, total number of cells, colony forming efficiency (CFE), morphology and immunocytochemistry against p63- α and cytokeratins 3 and 12 (CK3-CK12) were analyzed. PRGF was also used to elaborate a fibrin membrane. The effects of the scaffold on the preservation of stemness and the phenotypic characterization of LEPCs were investigated through analysis of CK3-CK12, ABCG-2 and p63. LEPCs cultivated with PRGF showed a significantly higher growth area than FBS cultures. Moreover, the number of cells were also higher in PRGF than FBS, while displaying a better morphology overall. CFE was found to be also higher in PRGF groups compared to FBS, and the p63-α expression also differed between groups. LEPCs cultivated on PRGF membranes appeared as a confluent monolayer of cells and still retained p63 and ABCG-2 expression, being negative for CK3-CK12. PRGF can be used in corneal tissue engineering, supplementing the culture media, even in a basal media without any other additives, as well as providing a scaffold for the culture. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. The effect of culture medium and carrier on explant culture of human limbal epithelium: A comparison of ultrastructure, keratin profile and gene expression.

    Science.gov (United States)

    Pathak, Meeta; Olstad, O K; Drolsum, Liv; Moe, Morten C; Smorodinova, Natalia; Kalasova, Sarka; Jirsova, Katerina; Nicolaissen, Bjørn; Noer, Agate

    2016-12-01

    Patients with limbal stem cell deficiency (LSCD) often experience pain and photophobia due to recurrent epithelial defects and chronic inflammation of the cornea. Successfully restoring a healthy corneal surface in these patients by transplantation of ex vivo expanded human limbal epithelial cells (LECs) may alleviate these symptoms and significantly improve their quality of life. The clinical outcome of transplantation is known to be influenced by the quality of transplanted cells. Presently, several different protocols for cultivation and transplantation of LECs are in use. However, no consensus on an optimal protocol exists. The aim of this study was to examine the effect of culture medium and carrier on the morphology, staining of selected keratins and global gene expression in ex vivo cultured LECs. Limbal biopsies from cadaveric donors were cultured for three weeks on human amniotic membrane (HAM) or on tissue culture coated plastic (PL) in either a complex medium (COM), containing recombinant growth factors, hormones, cholera toxin and fetal bovine serum, or in medium supplemented only with human serum (HS). The expanded LECs were examined by light microscopy (LM), transmission electron microscopy (TEM), immunohistochemistry (IHC) for keratins K3, K7, K8, K12, K13, K14, K15 and K19, as well as microarray and qRT-PCR analysis. The cultured LECs exhibited similar morphology and keratin staining on LM, TEM and IHC examination, regardless of the culture condition. The epithelium was multilayered, with cuboidal basal cells and flattened superficial cells. Cells were attached to each other by desmosomes. Adhesion complexes were observed between basal cells and the underlying carrier in LECs cultured on HAM, but not in LECs cultured on PL. GeneChip Human Gene 2.0 ST microarray (Affymetrix) analysis revealed that 18,653 transcripts were ≥2 fold up or downregulated (p ≤ 0.05). Cells cultured in the same medium (COM or HS) showed more similarities in gene

  19. Efficient animal-serum free 3D cultivation method for adult human neural crest-derived stem cell therapeutics

    Directory of Open Access Journals (Sweden)

    JFW Greiner

    2011-12-01

    Full Text Available Due to their broad differentiation potential and their persistence into adulthood, human neural crest-derived stem cells (NCSCs harbour great potential for autologous cellular therapies, which include the treatment of neurodegenerative diseases and replacement of complex tissues containing various cell types, as in the case of musculoskeletal injuries. The use of serum-free approaches often results in insufficient proliferation of stem cells and foetal calf serum implicates the use of xenogenic medium components. Thus, there is much need for alternative cultivation strategies. In this study we describe for the first time a novel, human blood plasma based semi-solid medium for cultivation of human NCSCs. We cultivated human neural crest-derived inferior turbinate stem cells (ITSCs within a blood plasma matrix, where they revealed higher proliferation rates compared to a standard serum-free approach. Three-dimensionality of the matrix was investigated using helium ion microscopy. ITSCs grew within the matrix as revealed by laser scanning microscopy. Genetic stability and maintenance of stemness characteristics were assured in 3D cultivated ITSCs, as demonstrated by unchanged expression profile and the capability for self-renewal. ITSCs pre-cultivated in the 3D matrix differentiated efficiently into ectodermal and mesodermal cell types, particularly including osteogenic cell types. Furthermore, ITSCs cultivated as described here could be easily infected with lentiviruses directly in substrate for potential tracing or gene therapeutic approaches. Taken together, the use of human blood plasma as an additive for a completely defined medium points towards a personalisable and autologous cultivation of human neural crest-derived stem cells under clinical grade conditions.

  20. Scalable cultivation of human pluripotent stem cells on chemically-defined surfaces

    Science.gov (United States)

    Hsiung, Michael Chi-Wei

    Human stem cells (SCs) are classified as self-renewing cells possessing great ability in therapeutic applications due of their ability to differentiate along any major cell lineage in the human body. Despite their restorative potential, widespread use of SCs is hampered by strenuous control issues. Along with the need for strict xeno-free environments to sustain growth in culture, current methods for growing human pluripotent stem cells (hPSCs) rely on platforms which impede large-scale cultivation and therapeutic delivery. Hence, any progress towards development of large-scale culture systems is severely hindered. In a concentrated effort to develop a scheme that can serve as a model precursor for large scale SC propagation in clinical use, we have explored methods for cultivating hPSCs on completely defined surfaces. We discuss novel approaches with the potential to go beyond the limitations presented by current methods. In particular, we studied the cultivation of human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs) on surface which underwent synthetic or chemical modification. Current methods for hPSCs rely on animal-based extracellular matrices (ECMs) such as mouse embryonic fibroblasts (MEFs) or feeders and murine sacoma cell-derived substrates to facilitate their growth. While these layers or coatings can be used to maximize the output of hPSC production, they cannot be considered for clinical use because they risk introducing foreign pathogens into culture. We have identified and developed conditions for a completely defined xeno-free substrate used for culturing hPSCs. By utilizing coupling chemistry, we can functionalize ester groups on a given surface and conjugate synthetic peptides containing the arginine-glycine-aspartic acid (RGD) motif, known for their role in cell adhesion. This method offers advantages over traditional hPSC culture by keeping the modified substrata free of xenogenic response and can be scaled up in

  1. Effects of aging on the biological characteristics of cultured limbal stem cells on the corneal stroma as a carrier in vitro%增龄对角膜基质载体培养的角膜缘干细胞生物学特性的影响

    Institute of Scientific and Technical Information of China (English)

    梁星; 马蕾; 于花

    2009-01-01

    目的 观察增龄对新西兰兔角膜缘干细胞在同种异体角膜基质上生长、增殖的影响.方法 用酶消化法将不同年龄新西兰兔角膜缘组织制成细胞悬液培养,以相同的细胞密度种植于不同年龄的新西兰兔的角膜基质上,观察角膜缘干细胞在角膜幕质上的生长情况.原位杂交检测ABCG2、ANp63的表达,IPP5.1软件分析图像,流式细胞术测细胞周期,运用SPSS13.0软件对析因设计资料进行方差分析.结果 角膜缘干细胞供体年龄各水平差异有统汁学意义,相同时间内角膜基质培养的青年兔角膜缘干细胞在角膜基质单位面积卜的牛长总而积均较中年和老年高,增殖期细胞所占比例大;而角膜基质供体年龄各水平差异与角膜缘干细胞和角膜基质的交互作用均无统计学意义.结论 在同种异体角膜基质载体上培养的角膜缘干细胞的增殖能力随着年龄的增加而降低.%Objective To investigate the effects of aging on the growth and proliferation of cultured limbai stem cells(LSCs)from New Zealand rabbits in aliogeneic corneal stroma.Methods Limbal epithelium harvested from New Zealand rabbits of different ages were enzymatically cleft into single cell suspension and cultured,and limbal stem cells were seeded at a same cell density in the corneal stroma of different age of New Zealand white rabbits.The growth status of LSCs seeded in the corneal stroma was observed while identification was performed using in situ hybridization,image was analyzed in IPP5.1 software,cell cycle was examined by flow cytometry,and the experimental data was analysed by ANOVA of factorial design.Results The difference in the level of LSCs donor age has statistical significance,as the total growth area of LSCs in unit area of corneal stroma and the ratio of proliferating cells were the highest in the young rabbits compared with the middle-aged and elder rabbits;the difference in the level of corneal stroma donor

  2. TISSEEL纤维蛋白胶在翼状胬肉切除联合自体结膜角膜缘干细胞移植的应用%Application of TISSEEL fibrin glue in pterygium excision combined with autogrifts conjunctival limbal stem cell

    Institute of Scientific and Technical Information of China (English)

    牟洁

    2016-01-01

    Objective:the clinical applications TISSEEL fibrin glue (Tisseel fibrin glue)in pterygium excision combined with autogrifts conjunctival limbal stem cell.Methods:In Oct 2014 to July 2015,the nine cases (9 eyes)had nasal pterygium were collected for clinical applications in our depart-ment,all using TISSEEL fibrin glue,underwent pterygium excision combined with autogrifts conjunctival limbal stem cell.Postoperative five patients were wear soft contact lens fort 3-5 days,four cases no wear.Results:Patients were followed up 6 mo,8 cases had no recurrence,1case recurrence,re-currence rate 11.1%.Conclusion:TISSEEL fibrin glue is applied pterygium excision is safe and effective and convenient,and can shorten the operation time,less discomfort for the patient,less postoperative inflammation,rapid recovery,low recurrence rate.%目的:探讨TISSEEL纤维蛋白胶(Tisseel fibrin glue)在翼状胬肉切除联合自体结膜角膜缘干细胞移植术的应用情况。方法:收集(2014-04/2015-03)我院眼科门诊翼状胬肉患者9例共9眼,全部使用TISSEEL纤维蛋白胶,均行翼状胬肉切除联合自体结膜角膜缘干细胞移植术,其中5例术后配戴治疗型软性角膜接触镜3-5天,4例无戴。结果:观察手术时间、术后结膜植片贴附情况,球结膜充血及结膜下出血,以及患者术眼不适症状。术后随访6个月,8例无复发。1例复发。结论:TISSEEL纤维蛋白胶应用于翼状胬肉切除是安全有效又方便的,并可缩短手术时间,减轻术后眼部不适感,术后炎症反应轻,恢复快,复发率低。

  3. Embryoid Body-Explant Outgrowth Cultivation from Induced Pluripotent Stem Cells in an Automated Closed Platform

    Science.gov (United States)

    Tone, Hiroshi; Yoshioka, Saeko; Akiyama, Hirokazu; Nishimura, Akira; Ichimura, Masaki; Nakatani, Masaru; Kiyono, Tohru

    2016-01-01

    Automation of cell culture would facilitate stable cell expansion with consistent quality. In the present study, feasibility of an automated closed-cell culture system “P 4C S” for an embryoid body- (EB-) explant outgrowth culture was investigated as a model case for explant culture. After placing the induced pluripotent stem cell- (iPSC-) derived EBs into the system, the EBs successfully adhered to the culture surface and the cell outgrowth was clearly observed surrounding the adherent EBs. After confirming the outgrowth, we carried out subculture manipulation, in which the detached cells were simply dispersed by shaking the culture flask, leading to uniform cell distribution. This enabled continuous stable cell expansion, resulting in a cell yield of 3.1 × 107. There was no evidence of bacterial contamination throughout the cell culture experiments. We herewith developed the automated cultivation platform for EB-explant outgrowth cells. PMID:27648449

  4. Total flavonoid content and antioxidant activity in leaves and stems extract of cultivated and wild tabat barito (Ficus deltoidea Jack)

    Science.gov (United States)

    Manurung, Hetty; Kustiawan, Wawan; Kusuma, Irawan W.; Marjenah

    2017-02-01

    Tabat barito (Ficus deltoidea Jack) is a name given by Dayak Tribe who lived in Borneo-Kalimantan and it is belongs to the moraceae. Almost all of the parts of F. deltoidea plant is widely used as a medicinal property. The total flavonoid content (TFC) and antioxidant activity from cultivated and wild F. deltoidea leaves and stems extract were assessed. Total flavonoid content was estimated by using Aluminium chloride colorimetric method and expressed as catechin equivalents (mg CE g-1 extract) and the antioxidant activity by the DPPH (2,2-diphenyl-1-picryl hydrazyl) method. The content of total flavonoid of leaves and stems (430.77 and 371.80 µg CE mg-1 extract) of cultivated F. deltoidea were higher than in the wild leaves and stems (114.82 and 66.67 µg CE mg-1 extract). The IC50 of leaves extract of cultivated and wild F. deltoidea, based on the DPPH assay, has a strong antioxidant activity (34.19 and 39.31 µg mL-1 extract) as compared to stems extract. These results showed that the cultivated F. deltoidea are suitable source for medicinal properties and the leaves could be exploited as source of natural antioxidants.

  5. Microfluidic devices for stem-cell cultivation, differentiation and toxicity testing

    Science.gov (United States)

    Becker, Holger; Hansen-Hagge, Thomas; Kurtz, Andreas; Mrowka, Ralf; Wölfl, Stefan; Gärtner, Claudia

    2017-02-01

    The development of new drugs is time-consuming, extremely expensive and often promising drug candidates fail in late stages of the development process due to the lack of suitable tools to either predict toxicological effects or to test drug candidates in physiologically relevant environments prior to clinical tests. We therefore try to develop diagnostic multiorgan microfluidic chips based on patient specific induced pluripotent stem cell (iPS) technology to explore liver dependent toxic effects of drugs on individual human tissues such as liver or kidney cells. Based initially on standardized microfluidic modules for cell culture, we have developed integrated microfluidic devices which contain different chambers for cell/tissue cultivation. The devices are manufactured using injection molding of thermoplastic polymers such as polystyrene or cyclo-olefin polymer. In the project, suitable surface modification methods of the used materials had to be explored. We have been able to successfully demonstrate the seeding, cultivation and further differentiation of modified iPS, as shown by the use of differentiation markers, thus providing a suitable platform for toxicity testing and potential tissue-tissue interactions.

  6. 分期实施异体角膜缘干细胞移植与穿透性角膜移植术治疗严重化学伤%A staged penetrating keratoplasty following limbal stem cells allograft in severe chemical injury leading to successful restoration of the ocular surface anatomy

    Institute of Scientific and Technical Information of China (English)

    Ali Hassan Alashwal; Raja Azmi Mohd Noor; Mohtar Ibrahim

    2008-01-01

    A 62-year-old man presented with severe bilateral ocular surface chemical injury and history of failed penetrating keratoplasty of right eye in 1996. Visual acuity was hand movement in right eye and light perception in left eye. Staged procedures of limbal stem cells allograft followed by penetrating keratoplasty have been done and resulted in good ocular surface restoration and rehabilitation of vision in right eye.%有1位于1996年实施右眼穿透性角膜移植术失败的双眼严重眼表化学伤的患者,62岁,右眼视力手动,左眼视力光感,于2006-09-16/2007-02-07分别对右眼实施了异体角膜缘干细胞移植术和穿透性角膜移植术,经过术后5mo的药物治疗观察,最终获得了右眼最佳矫正视力为6/30,角膜移植片透明,眼表得以重建,并未发现明显排斥迹象的良好效果.

  7. Mechanism of embryonic stem cells microenvironment enhancing stemness and inhibiting apoptosis of human limbal stem cells%胚胎干细胞微环境增强人角膜缘干细胞的干性和抑制凋亡的机制

    Institute of Scientific and Technical Information of China (English)

    刘志平; 沙翔垠; 王智崇; 李朝阳; 刘颖; 周瑾

    2015-01-01

    均有统计学意义(均P<0.01);ESCCM培养组第2代细胞中干细胞标志物蛋白及TERT蛋白表达量均明显高于CnT-20培养组,差异均有统计学意义(均P<0.01).siRNA-TERT转染组细胞端粒酶活性为(4.83±0.67)%,明显低于siRNA-F转染组的(46.71±1.22)%,差异有统计学意义(t=52.116,P=0.000).ESC-CM培养组培养液中添加了FAK抑制剂和GSK3β抑制剂以及转染TERT-siRNA后,细胞中pFAK、pAkt、pGSK3β的表达明显减弱,而p21的表达增强.ESC-CM培养组第2代LSCs及siRNA-F转染组细胞的线粒体膜电位明显高于CnT-20培养组和siRNA-TERT 转染组,差异均有统计学意义(均P<0.01);ESC-CM培养组原代和第2代细胞中及siRNA-F转染组细胞中ROS表达比例均明显低于CnT-20培养组及siRNA-TERT转染组,差异均有统计学意义(均P<0.01). 结论 ESC-CM培养体系可促进LSCs干性的维持,抑制细胞凋亡,其机制可能与端粒酶-p21-线粒体通路及FAK/Wnt 信号通路的激活有关.%Background The fate of adult stem cells is associated with its surrounding microenviroment.Our previous work found that embryonic stem cells (ESCs) micro-environment enhance the stemness of human limbal stem cells (LSCs),but its mechanism has not been elucidated.Objective This study was to explore the molecular mechanism of ESC micro-environment enhancing the stemness and inhibiting the apoptosis of LSCs.Methods Human LSCs were cultured by explant culture method with CnT-20 medium and CnT-20+20% ES culture supernatant (ESC-CM),respectively.Colony formation assay was used to analyze the proliferation ability of cells.Telomerase reverse transcriptase (TERT) siRNA (19-25nt siRNA) or siRNA (sc-37007) was transfected into the cells of ESCCM group.Apoptosis and mitochondrial membrane potential were assayed by flow cytometry,and the expressions of telomerase and reactive oxygen species (ROS) in TERT siRNA-or siRNA-F-transfected cells by immunofluorescence and flow cytomery.RT-PCR,immunofluorescence staining and

  8. Ex-vivo Potential of Cadaveric and Fresh Limbal Tissues to Regenerate Cultured Epithelium

    Directory of Open Access Journals (Sweden)

    Vemuganti Geeta

    2004-01-01

    Full Text Available Purpose: To evaluate and compare the ex-vivo growth potential and formation of cultured corneal epithelium from residual corneo-limbal rings obtained from the operating room after penetrating keratoplasty, and fresh limbal tissues from patients undergoing routine cataract surgery. Methods: With the approval of the Institutional Review Board and informed consent from patients, 1-2mm of limbal tissues from 15 patients and 31 tissues from the cadaveric limbal ring preserved in MK medium (16 tissues and Optisol (15 tissues were used for the study. Donor data included age, time lapse between death and collection, collection and preservation and preservation and culture. Tiny bits of the limbal tissue were explanted on the de-epithelialised human amniotic membrane prepared following standard guidelines, and cultured using Human Corneal Epithelial cell medium. Radial growth from the explant was observed and measured by phase contrast microscopy over 2-4 weeks. After adequate confluent growth, whole mount preparation of the membrane was made and stained with haematoxylin and eosin. Part of the membrane was fixed in formalin and processed for routine histologic examination. The sections were stained with haematoxylin and eosin. Results: Forty-six tissues were evaluated from 42 eyes (15 from patients, 31 from cadaveric eyes with a mean age of 55.3 years ± 21.23 years (range 18 years - 110 years. The growth pattern observed was similar in all the positive cases with clusters of cells budding from the explant over 24- 72 hours, and subsequent formation of a monolayer over the next 2-3 weeks. The stained whole mount preparation showed a radial growth of cells around explants with diameter ranging from 5 to 16mm. Histologic evaluation of the membrane confirmed the growth of 2-3 cell-layered epithelium over the amniotic membrane. Cultivated epithelium around explant cell cultures was observed in 100% (15/15 of limbal tissue obtained from patients, as against

  9. A comparative study on rabbit bone mesenchymal stem cells and human amniotic epithelial cells transplantation for rabbit limbal stem cell deficiency%兔骨髓间充质干细胞及人羊膜上皮细胞移植治疗兔角膜缘干细胞缺损的研究

    Institute of Scientific and Technical Information of China (English)

    卢建民; 吕秀丽; 马翔

    2011-01-01

    Background Limbal stem cell deficiency usually leads to blindness, and traditional therapy is limited. Recent research demonstrated that bone mesenchymal stem cells ( BMSCs ) and human amniotic epithelial cells(AECs) could differentiate into many kinds of cells including corneal epithelial cells, but the outcome and effect of these cells on corneal stem cell deficiency are still unclear. Objective This study aimed to observe and compare the effects of rabbit BMSCs and human AECs transplantation for rabbit limbal stem cell deficiency. Methods Eighteen clean New Zealand rabbits were randomly divided into the amniotic stroma(AS) group, rabbit BMSCs group and human AECs group with 6 rabbits for each group. Limbal stem cell deficiency models were established by putting a piece of filter paper that had been soaked in a NaOH solution at the corneal center. Rabbit BMSCs were isolated and purified by density gradient centrifugation combined with the attachment culture method, and human AECs were collected by a sequential trypsin digestion technique,and the third generation rabbit BMSCs and the first generation human AECs were identified with RT-PCR. After that,cells were inoculated onto the denuded AS and grafted to the corneal surface of the experimental animals. Twenty-eight days after cell transplantation, the therapeutic effects were evaluated based on the corneal neovascularization and opacity scores. Corneal histopathological examination and immunohistochemistry were performed to evaluate and compare the effectiveness among AS,rabbit BMSCs and human AECs on corneal stem cell deficiency. The procedure complied with the Regulations for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission. Results The third generation of rabbit BMSCs grew well after 12 hours, and the first generation of human AECs formed a membrane-like monolayer after 48 hours of incubation on AS. Immunohistochemistry staining showed that, 28 days after

  10. Preliminary Evidence that the Limbal Ring Influences Facial Attractiveness

    Directory of Open Access Journals (Sweden)

    Darren Peshek

    2011-04-01

    Full Text Available The limbal ring of the eye appears as a dark annulus where the iris meets the sclera. Both width and opacity of the limbal ring are influenced by iris pigmentation and optical properties of the region. With age the limbal ring becomes less prominent, making it a probabilistic indicator of youth and health. This raises the question: Are judgments of facial attractiveness sensitive to this signal in a potentially adaptive way? Here we show that the answer is yes. For male and female observers, both male and female faces with a dark and distinct limbal ring are rated as more attractive than otherwise identical faces with no limbal ring. This result is observed not just for upright faces but also for inverted faces, suggesting that the limbal ring is processed primarily as a local feature rather than as a configural feature in the analysis of facial beauty. We also discuss directions for future research that can clarify the role of the limbal ring in the visual perception of facial attractiveness.

  11. Enhanced differentiation of embryonic stem cells using co-cultivation with hepatocytes.

    Science.gov (United States)

    Moore, Rebecca N; Dasgupta, Anouska; Rajaei, Nayyereh; Yarmush, Martin L; Toner, Mehmet; Larue, Lionel; Moghe, Prabhas V

    2008-12-15

    We examined the effects of co-cultivated hepatocytes on the hepatospecific differentiation of murine embryonic stem (ES) cells. Utilizing an established mouse ES cell line expressing high or low levels of E-cadherin, that we have previously shown to be responsive to hepatotrophic growth factor stimulation (Dasgupta et al., 2005. Biotechnol Bioeng 92(3):257-266), we compared co-cultures of cadherin-expressing ES (CE-ES) cells with cultured rat hepatocytes, allowing for either paracrine interactions (indirect co-cultures) or both juxtacrine and paracrine interactions (direct co-cultures, random and patterned). Hepatospecific differentiation of ES cells was evaluated in terms of hepatic-like cuboidal morphology, heightened gene expression of late maturation marker, glucose-6-phosphatase in relation to early marker, alpha-fetoprotein (AFP), and the intracellular localization of albumin. Hepatocytes co-cultured with growth factor primed CE-ES cells markedly enhanced ES cell differentiation toward the hepatic lineage, an effect that was reversed through E-cadherin blockage and inhibited in control ES cells with reduced cadherin expression. Comparison of single ES cell cultures versus co-cultures show that direct contact co-cultures of hepatocytes and CE-ES cells maximally promoted ES cell commitment towards hepatodifferentiation, suggesting cooperative effects of cadherin-based juxtacrine and paracrine interactions. In contrast, E-cadherin deficient mouse ES (CD-ES) cells co-cultured with hepatocytes failed to show increased G6P expression, confirming the role of E-cadherin expression. To establish whether albumin expression in CE-ES cells was spatially regulated by co-cultured hepatocytes, we co-cultivated CE-ES cells around micropatterned, pre-differentiated rat hepatocytes. Albumin localization was enhanced "globally" within CE-ES cell colonies and was inhibited through E-cadherin antibody blockage in all but an interfacial band of ES cells. Thus, stem cell based

  12. Chronic inflammatory cells and damaged limbal cells in pterygium

    African Journals Online (AJOL)

    EB

    2013-09-03

    Sep 3, 2013 ... Background: Chronic inflammation in pterygium occurrence has not been explained. ... Methods: Chronic inflammatory changes and damaged limbal basal epithelial cells were assessed in 59 samples. ..... Acute and chronic.

  13. In vivo osteoinductive effect and in vitro isolation and cultivation bone marrow mesenchymal stem cells.

    Science.gov (United States)

    Redzić, Amira; Smajilagić, Amer; Aljicević, Mufida; Berberović, Ljubomir

    2010-12-01

    Bone marrow contains cell type termed mesenchymal stem cells (MSC), first recognized in bone marrow by a German pathologist, Julius Cohnheim in 1867. That MSCs have potential to differentiate in vitro in to the various cells lines as osteoblast, chondroblast, myoblast and adipoblast cells lines. Aims of our study were to show in vivo capacity of bone marrow MSC to produce bone in surgically created non critical size mandible defects New Zeland Rabbits, and then in second part of study to isolate in vitro MSC from bone marrow, as potential cell transplantation model in bone regeneration. In vivo study showed new bone detected on 3D CT reconstruction day 30, on all 3 animals non critical size defects, treated with bone marrow MSC exposed to the human Bone Morphogenetic Protein 7 (rhBMP-7). Average values of bone mineral density (BMD), was 530 mg/cm3, on MSC treated animals, and 553 mg/cm3 on control group of 3 animals where non critical size defects were treated with iliac crest autologue bone graft. Activity of the Alkaline Phosphatase enzyme were measurement on 0.5, 14, 21, 30 day and increased activity were detected day 14 on animals treated with bone marrow MSCs compared with day 30 on iliac crest treated animals. That results indicates strong osteoinduction activity of the experimental bone marrow MSCs models exposed to the rhBMP-7 factor Comparing ALP activity, that model showed superiorly results than control group. That result initiates us in opinion that MSCs alone should be alternative for the autolologue bone transplantation and in vitro study we isolated singles MSCs from the bone marrow of rat's tibia and femora and cultivated according to the method of Maniatopoulos et all. The small initial colonies of fibroblast like cells were photo-documented after 2 days of primary culture. Such isolated and cultivated MSCs in future studies will be exposed to the growth factors to differentiate in osteoblast and indicate their clinically potential as alternative

  14. Transforming ocular surface stem cell research into successful clinical practice

    Directory of Open Access Journals (Sweden)

    Virender S Sangwan

    2014-01-01

    Full Text Available It has only been a quarter of a century since the discovery of adult stem cells at the human corneo-scleral limbus. These limbal stem cells are responsible for generating a constant and unending supply of corneal epithelial cells throughout life, thus maintaining a stable and uniformly refractive corneal surface. Establishing this hitherto unknown association between ocular surface disease and limbal dysfunction helped usher in therapeutic approaches that successfully addressed blinding conditions such as ocular burns, which were previously considered incurable. Subsequent advances in ocular surface biology through basic science research have translated into innovations that have made the surgical technique of limbal stem cell transplantation simpler and more predictable. This review recapitulates the basic biology of the limbus and the rationale and principles of limbal stem cell transplantation in ocular surface disease. An evidence-based algorithm is presented, which is tailored to clinical considerations such as laterality of affliction, severity of limbal damage and concurrent need for other procedures. Additionally, novel findings in the form of factors influencing the survival and function of limbal stem cells after transplantation and the possibility of substituting limbal cells with epithelial stem cells of other lineages is also discussed. Finally this review focuses on the future directions in which both basic science and clinical research in this field is headed.

  15. Response of human limbal epithelial cells to wounding on 3D RAFT tissue equivalents: effect of airlifting and human limbal fibroblasts.

    Science.gov (United States)

    Massie, Isobel; Levis, Hannah J; Daniels, Julie T

    2014-10-01

    Limbal epithelial stem cell deficiency can cause blindness but may be treated by human limbal epithelial cell (hLE) transplantation, normally on human amniotic membrane. Clinical outcomes using amnion can be unreliable and so we have developed an alternative tissue equivalent (TE), RAFT (Real Architecture for 3D Tissue), which supports hLE expansion, and stratification when airlifted. Human limbal fibroblasts (hLF) may be incorporated into RAFT TEs, where they support overlying hLE and improve phenotype. However, the impact of neither airlifting nor hLF on hLE function has been investigated. hLE on RAFT TEs (±hLF and airlifting) were wounded using heptanol and re-epithelialisation (fluorescein diacetate staining), and percentage putative stem cell marker p63α and proliferative marker Ki67 expression (wholemount immunohistochemistry), measured. Airlifted, hLF- RAFT TEs were unable to close the wound and p63α expression was 7 ± 0.2% after wounding. Conversely, non-airlifted, hLF- RAFT TEs closed the wound within 9 days and p63α expression was higher at 22 ± 5% (p < 0.01). hLE on both hLF- and hLF+ RAFT TEs (non-airlifted) closed the wound and p63α expression was 26 ± 8% and 36 ± 3% respectively (ns). Ki67 expression by hLE increased from 1.3 ± 0.5% before wounding to 7.89 ± 2.53% post-wounding for hLF- RAFT TEs (p < 0.01), and 0.8 ± 0.08% to 17.68 ± 10.88% for hLF+ RAFT TEs (p < 0.05), suggesting that re-epithelialisation was a result of proliferation. These data suggest that neither airlifting nor hLF are necessarily required to maintain a functional epithelium on RAFT TEs, thus simplifying and shortening the production process. This is important when working towards clinical application of regenerative medicine products.

  16. Limbal and corneal calcification in patients with chronic renal failure.

    Science.gov (United States)

    Klaassen-Broekema, N; van Bijsterveld, O P

    1993-09-01

    In patients with chronic renal failure on regular dialysis treatment, limboconjunctival degenerations and calcifications are commonly observed. In this study three groups of patients were followed over a period of 6 years. The first group consisted of 47 patients with renal failure, the second group of 17 patients with renal failure and hyperparathyroidism not controlled by drugs, and the third group seven patients with primary hyperparathyroidism without renal failure. The aim of this study was to determine the progression of the limboconjunctival changes over time. The hypothesis that an increase in serum calcium and phosphorus concentrations, as a result of tertiary hyperparathyroidism, could possibly add a corneal component to the limbal calcification was also tested. All patients with renal failure (in as much as the degenerative limbal features were not obscured by deposits of lime salts), had a type II white limbus girdle of Vogt. This limbal degeneration was observed in only 45% of controls. In all 47 patients with renal failure conjunctival calcification was observed; 26 of them also had limbal calcification. After 6 years 41 patients had developed limbal calcification. This progression was statistically significant. In 15 out of 17 patients with tertiary hyperparathyroidism a band-shaped keratopathy developed in addition to the limboconjunctival calcification.

  17. Limbal dermoid in Nager acrofacial dysostosis: A rare case report

    Directory of Open Access Journals (Sweden)

    Rohit Malik

    2014-01-01

    Full Text Available Nager syndrome, also called preaxial acrofacial dysostosis, comprises two groups of defects involving the limbs and craniofacial region, respectively. This syndrome is rare and only 70 cases have been reported in the literature. The exact cause of this syndrome is unknown, but there is indication that it is genetically based. Ocular manifestations of this syndrome include widely separated downward slanting eyes, absence of eyelashes, ptosis of upper eyelids and colobomas on the inner aspect of lower eyelids. We report limbal dermoid in a patient with Nager syndrome. We did not find such an association of "Limbal dermoid in Nager acrofacial dysostosis syndrome" on PubMed using Nager acrofacial dysostosis, limbal dermoid and ocular manifestations as the keywords.

  18. Production Process for Stem Cell Based Therapeutic Implants: Expansion of the Production Cell Line and Cultivation of Encapsulated Cells

    Science.gov (United States)

    Weber, C.; Pohl, S.; Poertner, R.; Pino-Grace, Pablo; Freimark, D.; Wallrapp, C.; Geigle, P.; Czermak, P.

    Cell based therapy promises the treatment of many diseases like diabetes mellitus, Parkinson disease or stroke. Microencapsulation of the cells protects them against host-vs-graft reactions and thus enables the usage of allogenic cell lines for the manufacturing of cell therapeutic implants. The production process of such implants consists mainly of the three steps expansion of the cells, encapsulation of the cells, and cultivation of the encapsulated cells in order to increase their vitality and thus quality. This chapter deals with the development of fixed-bed bioreactor-based cultivation procedures used in the first and third step of production. The bioreactor system for the expansion of the stem cell line (hMSC-TERT) is based on non-porous glass spheres, which support cell growth and harvesting with high yield and vitality. The cultivation process for the spherical cell based implants leads to an increase of vitality and additionally enables the application of a medium-based differentiation protocol.

  19. PHOTOCHEMICAL TISSUE BONDING TECHNIQUE FOR REPAIRING LIMBAL STEM CELL DEFICIENCY%光化学组织黏合技术在修复角膜缘干细胞缺失中的应用

    Institute of Scientific and Technical Information of China (English)

    顾钏; 王莹; 姚敏; 方勇

    2011-01-01

    Objective To investigate the feasibility of photochemical tissue bonding (PTB) technique in repairinglimbal stem cell (LSC) deficiency and the effect on cornea wound healing. Methods LSCs were isolated from limbus of New Zealand rabbits by tissue block culture method, and then the LSCs of 2nd passage were cultured on de-epithelialized human amniotic membrane (HAM) for 3 weeks to prepare the HAM/LSC grafts. The LSC deficiency models of the left eyes were established by 0.5 mol/L NaOH in 24 New Zealand female rabbits, aged 3-4 months and weighing 1.5-2.0 kg. HAM/LSC grafts were used to repair the cornea wounds by sutures (suture group, n=12) or by PTB technique (PTB group, n=12). The gross was observed including the corneal transparency, erythema, and new blood vessel formation after surgery. At 3 and 28 days, the inflammatory cytokine of interleukin lβ (IL-1β), IL-6, and tumor necrosis factor a (TNF-α) were assayed by ELISA method; and the amount of new blood vessels were quantified by immunohistochemistry staining at 28 days. Results All animals survived to the end of the experiment. At 3 days, there was no obvious difference in the corneal transparency between 2 groups; at 28 days, the corneal transparency of PTB group was higher than that of suture group, and new blood vessels decreased. HE staining showed that mass inflammatory cells infiltrated between graft and cornea basal layer at 3 days, and no new blood vessel formed, inflammatory cells infiltration significantly decreased at 28 days in PTB group; the amount of new blood vessels was (2.0 ± 0.8)/HP in PTB group and was (6.3 ± 1.3)/HP in suture group, showing significant difference ((=7.966, P=0.002). At 28 days, the concentrations of inflammatory cytokine of IL-1β, IL-6, and TNF-a in suture group were significantly higher than those in PTB group (P 0.05). Conclusion PTB technique can be used to fix HAM/LSC grafts, which can decrease inflammatory cell infiltration and new vessel formation, and improve

  20. Derivation of neurons with functional properties from adult limbal epithelium: implications in autologous cell therapy for photoreceptor degeneration.

    Science.gov (United States)

    Zhao, Xing; Das, Ani V; Bhattacharya, Sumitra; Thoreson, Wallace B; Sierra, Jorge Rodriguez; Mallya, Kavita B; Ahmad, Iqbal

    2008-04-01

    The limbal epithelium (LE), a circular and narrow epithelium that separates cornea from conjunctiva, harbors stem cells/progenitors in its basal layer that regenerate cornea. We have previously demonstrated that cells in the basal LE, when removed from their niche and cultured in reduced bond morphogenetic protein signaling, acquire properties of neural progenitors. Here, we demonstrate that LE-derived neural progenitors generate neurons with functional properties and can be directly differentiated along rod photoreceptor lineage in vitro and in vivo. These observations posit the LE as a potential source of neural progenitors for autologous cell therapy to treat photoreceptor degeneration in age-related macular degeneration and retinitis pigmentosa.

  1. Features of Microsystems for Cultivation and Characterization of Stem Cells with the Aim of Regenerative Therapy

    Directory of Open Access Journals (Sweden)

    Kihoon Ahn

    2016-01-01

    Full Text Available Stem cells have infinite potential for regenerative therapy thanks to their advantageous ability which is differentiable to requisite cell types for recovery and self-renewal. The microsystem has been proved to be more helpful to stem cell studies compared to the traditional methods, relying on its advantageous feature of mimicking in vivo cellular environments as well as other profitable features such as minimum sample consumption for analysis and multiprocedures. A wide variety of microsystems were developed for stem cell studies; however, regenerative therapy-targeted applications of microtechnology should be more emphasized and gain more attractions since the regenerative therapy is one of ultimate goals of biologists and bioengineers. In this review, we introduce stem cell researches harnessing well-known microtechniques (microwell, micropattern, and microfluidic channel in view point of physical principles and how these systems and principles have been implemented appropriately for characterizing stem cells and finding possible regenerative therapies. Biologists may gain information on the principles of microsystems to apply them to find solutions for their current challenges, and engineers may understand limitations of the conventional microsystems and find new chances for further developing practical microsystems. Through the well combination of engineers and biologists, the regenerative therapy-targeted stem cell researches harnessing microtechnology will find better suitable treatments for human disorders.

  2. Resistance among cultivated sunflower germplasm to stem-infesting pests in the central Great Plains.

    Science.gov (United States)

    Charlet, Laurence D; Aiken, Robert M; Miller, Jerry F; Seiler, Gerald J

    2009-06-01

    A 7-yr field study evaluated 61 oilseed sunflower, Helianthus annuus L., accessions and 31 interspecific crosses for resistance to attack by naturally occurring populations of three stem-infesting pests, the sunflower stem weevil, Cylindrocopturus adspersus (LeConte) (Coleoptera: Curculionidae); a longhorned beetle, Dectes texanus LeConte (Coleoptera: Cerambycidae); and a root boring moth, Pelochrista womonana (Kearfott) (Lepidoptera: Tortricidae), at two locations in the central Great Plains. Germplasm with potential sources of resistance to attack from all three stem-infesting species were revealed. Accessions PI 650558, PI 386230, and PI 431516 were consistent in averaging low densities of stem weevil larvae per stalk among lines tested, and PI 497939 exceeded 25 weevil larvae per stalk in only 1 yr of 5 yr of trials. Several interspecific crosses also had consistently low densities of C. adspersus larvae per stalk. Populations of both D. texanus and P. womonana were variable over years, but differences among the lines tested were evident in many trials, revealing potential for developing resistant germplasm. Four accessions (PI 386230, PI 431542, PI 650497, and PI 650558) had low larval densities of C. adspersus and P. womonana in addition to reduced percentage infestation by D. texanus. Results showed potential for developing resistant genotypes for these pests. The prospect of adding host plant resistance as an integrated pest management (IPM) tactic would provide another tool for reducing economic losses from stem-infesting insect pests of sunflower in the central Great Plains.

  3. Isolation, cultivation and identification of brain glioma stem cells by magnetic bead sorting

    Institute of Scientific and Technical Information of China (English)

    Xiuping Zhou; Chao Zheng; Qiong Shi; Xiang Li; Zhigang Shen; Rutong Yu

    2012-01-01

    This study describes a detailed process for obtaining brain glioma stem cells from freshly dissected human brain glioma samples using an immunomagnetic bead technique combined with serum-free media pressure screening. Furthermore, the proliferation, differentiation and self-renewal biological features of brain glioma stem cells were identified. Results showed that a small number of CD133 positive tumor cells isolated from brain glioma samples survived as a cell suspension in serum-free media and proliferated. Subcultured CD133 positive cells maintained a potent self-renewal and proliferative ability, and expressed the stem cell-specific markers CD133 and nestin. After incubation with fetal bovine serum, the number of glial fibrillary acidic protein and microtubule associated protein 2 positive cells increased significantly, indicating that the cultured brain glioma stem cells can differentiate into astrocytes and neurons. Western blot analysis showed that tumor suppressor phosphatase and tensin homolog was highly expressed in tumor spheres compared with the differentiated tumor cells. These experimental findings indicate that the immunomagnetic beads technique is a useful method to obtain brain glioma stem cells from human brain tumors.

  4. Human embryonic stem cell cultivation: historical perspective and evolution of xeno-free culture systems.

    Science.gov (United States)

    Desai, Nina; Rambhia, Pooja; Gishto, Arsela

    2015-02-22

    Human embryonic stem cells (hESC) have emerged as attractive candidates for cell-based therapies that are capable of restoring lost cell and tissue function. These unique cells are able to self-renew indefinitely and have the capacity to differentiate in to all three germ layers (ectoderm, endoderm and mesoderm). Harnessing the power of these pluripotent stem cells could potentially offer new therapeutic treatment options for a variety of medical conditions. Since the initial derivation of hESC lines in 1998, tremendous headway has been made in better understanding stem cell biology and culture requirements for maintenance of pluripotency. The approval of the first clinical trials of hESC cells for treatment of spinal cord injury and macular degeneration in 2010 marked the beginning of a new era in regenerative medicine. Yet it was clearly recognized that the clinical utility of hESC transplantation was still limited by several challenges. One of the most immediate issues has been the exposure of stem cells to animal pathogens, during hESC derivation and during in vitro propagation. Initial culture protocols used co-culture with inactivated mouse fibroblast feeder (MEF) or human feeder layers with fetal bovine serum or alternatively serum replacement proteins to support stem cell proliferation. Most hESC lines currently in use have been exposed to animal products, thus carrying the risk of xeno-transmitted infections and immune reaction. This mini review provides a historic perspective on human embryonic stem cell culture and the evolution of new culture models. We highlight the challenges and advances being made towards the development of xeno-free culture systems suitable for therapeutic applications.

  5. Five willow varieties cultivated across diverse field environments reveal stem density variation associated with high tension wood abundance.

    Science.gov (United States)

    Berthod, Nicolas; Brereton, Nicholas J B; Pitre, Frédéric E; Labrecque, Michel

    2015-01-01

    Sustainable and inexpensive production of biomass is necessary to make biofuel production feasible, but represents a challenge. Five short rotation coppice willow cultivars, selected for high biomass yield, were cultivated on sites at four diverse regions of Quebec in contrasting environments. Wood composition and anatomical traits were characterized. Tree height and stem diameter were measured to evaluate growth performance of the cultivars according to the diverse pedoclimatic conditions. Each cultivar showed very specific responses to its environment. While no significant variation in lignin content was observed between sites, there was variation between cultivars. Surprisingly, the pattern of substantial genotype variability in stem density was maintained across all sites. However, wood anatomy did differ between sites in a cultivar (producing high and low density wood), suggesting a probable response to an abiotic stress. Furthermore, twice as many cellulose-rich G-fibers, comprising over 50% of secondary xylem, were also found in the high density wood, a finding with potential to bring higher value to the lignocellulosic bioethanol industry.

  6. In Vivo Osteoinductive Effect and In Vitro Isolation and Cultivation Bone Marrow Mesenchymal Stem Cells

    OpenAIRE

    Redžić, Amira; Smajilagić, Amer; Aljičević, Mufida; Berberović, Ljubomir

    2010-01-01

    Bone marrow contains cell type termed Mesenchymal Stem Cells (MSC), first recognized in bone marrow by a German pathologist, Julius Cohnheim in 1867. That MSCs have potential to differentiate in vitro in to the various cells lines as osteoblast, chondroblast, myoblast and adipoblast cells lines. Aims of our study were to show in vivo capacity of bone marrow MSC to produce bone in surgically created non critical size mandible defects New Zeeland Rabbits, and then in second part of study to iso...

  7. In vitro cultivation and differentiation of fetal liver stem cells from mice

    Institute of Scientific and Technical Information of China (English)

    Ren Qing FENG; Li Ying DU; Zhen Quan GUO

    2005-01-01

    During embryonic development, pluripotent endoderm tissue in the developing foregut may adopt pancreatic fate or hepatic fate depending on the activation of key developmental regulators. Transdifferentiation occurs between hepatocytes and pancreatic cells under specific conditions. Hepatocytes and pancreatic cells have the common endodermal progenitor cells. In this study we isolated hepatic stem/progenitor cells from embryonic day (ED) 12-14 Kun-Ming mice with fluorescence-activated cell sorting (FACS). The cells were cultured under specific conditions. The cultured cells deploy dithizone staining and immunocytochemical staining at the 15th, 30th and 40th day after isolation. The results indicated the presence of insulin-producing cells. When the insulin-producing cells were transplanted into alloxaninduced diabetic mice, the nonfasting blood glucose level was reduced. These results suggested that fetal liver stem/progenitor cells could be converted into insulin-producing cells under specific culture conditions. Fetal liver stem/progenitor cells could become the potential source of insulin-producing cells for successful cell transplantation therapy strategies of diabetes.

  8. Experimental study on the culture and transplantation of limbal epithelium cells of rabbit%兔角膜缘上皮细胞培养与移植的实验研究

    Institute of Scientific and Technical Information of China (English)

    罗廷浩

    2012-01-01

    OBJECTIVE To study the treatment of autotransplantation on rabbit limbal stem cells lack by cultured limbal epithelium cells cultured on gelatin. METHODS Limbal epithelium cells had been cultured on gelatin in DMEM/HamF12 medium for one week, and cultured limbal epithelium cell had been marked with 'HTDR for one day, then limbal epithelium cells and gelatin were transplanted on the limbal and scleral of the rabbit model with lack of corneal stem cells by autotransplantation. The corneal changes were observed by a slillamp every day, the corneal pathological changes and 3HTDR content were examined. RESULTS Rabbit limbal epithelium cells continued to proliferate, differentiate and form multiple cell layers on gelatin. After autotransplantation with cultured epithelium cells and gelatin the rabbit epithelium showed corneal phenotype and progressive decrease of vascularity and stromal infiltration in the limbal and peripheral zone. Pathological examination verified that the limbal and peripheral corneal epithelium was composed of multilayer cells; the neu-vascularization was reduced and stromal inflammatory cells were decreased. The limbal content 3HTDR by isotope radioisotope was examined four weeks after operation. CONCLUSIONS Transplantation with cultured limbal epithelium cells could restore the composition of corneal epithelial cell, decrease neo-vascularization, maintain the function of limbal cellular barrier and provide better condition for later keratoplasty.%目的 观察以明胶为裁体培养的角膜缘上皮细胞移植治疗兔角膜缘干细胞缺乏症的疗效.方法 切除实验兔角膜缘组织并用NaOH处理制作角膜缘干细胞缺乏动物模型,切除的角膜缘上皮细胞在铺有明胶裁体的细胞培养板上培养5d后(角膜上皮细胞移植术前24 h)用3H胸腺嘧啶核苷标记,于模型动物上行角膜缘上皮细胞移植术,术后观察角膜修复情况,并做病理学检查及同位素检测.结果 1.细胞培养:兔角

  9. Cultivation and optimized tracing of rat bone marrow mesenchymal stem cells

    Directory of Open Access Journals (Sweden)

    Xiu-hua HE

    2011-02-01

    Full Text Available Objective To investigate labelling and tracing methods of bone marrow mesenchymal stem cells(MSCs of rat,and to optimize the trace labelling technique.Methods Rat MSCs were isolated and cultured in vitro.The surface antigens(CD29,CD34,CD45,CD90 of MSCs were identified by flow cytometry,and MSCs were labelled with BrdU,DAPI and GFP,respectively.The labelling efficiency of BrdU was aseessed with immunocytochemistry,and that of DAPI and GFP were observed under fluorescence microscope.The advantages and disadvantages of the three tracer techniques were analyzed.Results Flow cytometry showed that MSCs expressed CD29 and CD90 but not CD34 or CD45.The three kinds of markers showed no significant toxicity to the cells.The optimal dosage and timing of BrdU labeling were respectively 10 μmol/L and 48 hours.And that of DAPI labeling were 1μg/ml and 12 hours.The infected MSCs with lentivirus-GFP at MOI(multiplicity of infection = 8 for 12h expressed GFP with high efficiency(above 90%.Conclusion Comparison with the three tracing methods for MSCs,transfection with GFP gene is a stable,reliable,safe tracing method,and they are important in tracing adult stem cells.

  10. Controle genético das células-tronco humanas cultivadas Genetic control of cultivated human stem cells

    Directory of Open Access Journals (Sweden)

    Spencer L. M. Payão

    2009-05-01

    Full Text Available As células-tronco apresentam uma alta capacidade de autorregeneração, assim como, um potencial de diferenciação em uma variedade de tipos celulares. Estas células podem ser classificadas como embrionárias e adultas. Apesar de apresentar propriedades de células-tronco, as mesenquimais apresentam um certo grau de dificuldade no estabelecimento das culturas, podendo induzir a perda da expressão da enzima responsável pela imortalização ou enzima telomerase. A enzima telomerase é considerada um relógio biológico, um indicador que a senescência celular irá se instalar inevitavelmente. A questão mais atual e intrigante dos pesquisadores é se o suposto potencial de divisão, por um determinado período de tempo, das células-tronco cultivadas poderia levar ao acúmulo de alterações genéticas e epigenéticas, resultando em um processo neoplásico. Daí a importância do papel da citogenética humana no controle e monitoramento das células-tronco cultivadas que serão utilizadas na terapia em seres humanos. Alterações cromossômicas estruturais, tais como deleções, translocações e inversões, representam um mecanismo importante pelo qual as células cancerígenas desenvolvem-se gradualmente, uma vez que estas alterações cromossômicas podem levar a uma expressão anormal de muitos genes, podendo desencadear assim o processo neoplásico.Stem cells have a high capacity of self-regeneration, as well as a potential to differentiate into several cell types. These cells can be classified as embryonic or adult. In spite of having inherent properties of stem cells, mesenchymal cells show a certain degree of difficulty to establish cultures. This might induce a loss of the expression of the telomerase enzyme which is considered to be a biological clock or an indicator of the senescence of the cells. The most current and intriguing question for researchers is whether the presumed division potential of cultivated stem cells, over a

  11. Cultivating Diversity and Competency in STEM: Challenges and Remedies for Removing Virtual Barriers to Constructing Diverse Higher Education Communities of Success.

    Science.gov (United States)

    Whittaker, Joseph A; Montgomery, Beronda L

    2012-01-01

    The need to increase the number of college graduates in Science, Technology, Engineering, and Mathematics (STEM) disciplines is a national issue. As the demographics of the United States' population grow increasingly more diverse, the recognition that students of color are disproportionately under-represented among those individuals successful at completing STEM degrees requires exigent and sustained intervention. Although a range of efforts and funding have been committed to increasing the success of under-represented minority (URM) students at primarily white, or majority, institutions, widespread progress has been slow. Simultaneously, Historically Black Colleges and Universities and Minority Serving Institutions have demonstrated disproportionate successes in graduating URM students with STEM degrees and those that proceed to completing graduate-level degrees in the sciences. The differential successes of particular institutions with promoting the achievement of diverse individuals in obtaining academic STEM degrees suggest that with committed and strategic leadership, advancements in creating academic communities that promote the success of a diverse range of students in STEM can be achieved in part through assessing and mitigating environmental barriers that impede success at majority institutions. In this paper, we address issues related to the engagement of URM students in majority settings and describe some efforts that have shown success for promoting diversity in STEM and highlight continuing issues and factors associated with cultivating diversity in academic STEM disciplines at majority institutions. Recommended efforts include addressing academic assistance, professional and cultural socialization issues and institutional environmental factors that are associated with success or lack thereof for URMs in STEM.

  12. Five-Port Combined Limbal and Pars Plana Vitrectomy for Infectious Endophthalmitis

    Directory of Open Access Journals (Sweden)

    Kunyong  Xu

    2016-12-01

    Full Text Available Pars plana vitrectomy for acute infectious endophthalmitis can be challenging due to severe inflammation in the anterior chamber creating significant media opacity. We describe a surgical technique combining limbal based vitrectomy and pars plana vitrectomy to manage acute infectious endophthalmitis. Limbal based vitrectomy facilitates removal of anterior chamber fibrin and inflammatory membranes for safe and optimal posterior pars plana vitrectomy.

  13. Phacoemulsification after penetrating keratoplasty with autologous limbal transplant and amniotic membrane transplant in chemical burns

    Directory of Open Access Journals (Sweden)

    Arora Ritu

    2005-01-01

    Full Text Available We report a patient who had earlier penetrating keratoplasty with amniotic membrane transplant and autologous limbal cell transplant for chemical injury who underwent cataract surgery by phacoaspiration. A posterior limbal incision with corneal valve was made superotemporally with extreme caution to avoid damage to the limbal graft. Aspiration flow rates and vacuum were kept low to avoid any turbulence during surgery. A 6.0 mm optic diameter acrylic foldable intraocular lens was inserted in the bag. The patient achieved a best-corrected visual acuity of 6/12 at 10 months′ follow-up with a clear corneal graft. We conclude that caution during wound construction and phacoaspiration can help preserve corneal and limbal graft integrity in patients undergoing cataract surgery after corneal graft and limbal transplantation.

  14. Interleukin-10 Gene Transfer in Rat Limbal Transplantation.

    Science.gov (United States)

    Kaufmann, Claude; Mortimer, Lauren A; Brereton, Helen M; Irani, Yazad D; Parker, Douglas Ga; Anson, Donald S; Bachmann, Lucas M; Williams, Keryn A

    2017-09-19

    To evaluate the gene transfer of the interleukin (IL)-10 cytokine as a treatment modality for prolonging limbal allograft survival in a rat model. Adenoviral (AV) and lentiviral (LV) vectors were produced for ex vivo gene transfer into limbal graft tissue prior to orthotopic transplantation. Experimental groups comprised unmodified isografts, unmodified allografts, allografts transfected with a reporter gene, and allografts transfected with IL-10. The functional effects of the transgenes were determined by clinical assessment and by following donor cell survival in the recipient animal. Group comparisons were made using survival analysis and tested with the log-rank test. Differences in mean rejection times between groups were tested using the Wilcoxon rank-sum test. Isografts survived during the entire observation period of 56 days. Allografts underwent clinical rejection at a mean of 6.7 days (standard deviation 2.0) postoperatively, irrespective of the presence of transgenes (p < 0.001 for difference in rejection times). For both the AV and LV vector systems, Kaplan-Meier analysis showed a statistically significant difference with respect to time-to-graft failure when comparing allografts transfected with IL-10 with allografts transfected with reporter gene alone (p = 0.011 and p < 0.001, respectively). In the isografts, donor cells could be detected during the complete observation period. In all the allograft groups, however, donor cell detection declined after 1 week and was lost after 4 weeks. Under the conditions tested in the present model, both the AV and the LV vector systems were able to transfect limbal graft tissue ex vivo with biologically active IL-10, leading to delayed rejection compared to the controls.

  15. A case of endophthalmitis associated with limbal relaxing incision

    Directory of Open Access Journals (Sweden)

    Aravind Haripriya

    2012-01-01

    Full Text Available Limbal relaxing incisions (LRIs are considered a relatively safe procedure with rapid stabilization and absence of infectious complications. Do we need to readdress this last impression? We report a case of nocardia endophthalmitis associated with an exudate at the site of an LRI in a patient who underwent routine cataract surgery. This case, to the best of our knowledge, is the first report of its kind, stressing the need for a cautious approach to the adoption of this method of astigmatic correction.

  16. Reconstruction of the limbal vasculature after limbal-conjunctival autograft transplantation in pterygium surgery: an angiography study.

    Science.gov (United States)

    Kim, Yong Joon; Yoo, Seung Hoon; Chung, Jin Kwon

    2014-11-18

    We evaluated the angiographic features of the affected limbus in patients with pterygia and assessed limbal reconstruction outcomes after limbal-conjunctival autograft (LCA) transplantation in terms of vascular remodeling. We studied prospectively 31 eyes of 31 patients who underwent pterygium excision and LCA transplantation; 28 eyes of 28 normal participants served as controls. Anterior segment indocyanine green angiography (ICGA) was performed for each participant preoperatively and at 1 week, and 1 and 3 months postoperatively. The perioperative angiographic features of the pterygium were compared to those in normal eyes. The structural changes of the marginal corneal vascular arcades (MCAs) and LCA were quantitatively assessed postoperatively in terms of vascular density and lacunarity. Deteriorated MCAs that extended beyond the pterygium head were observed in the pterygium group. The pterygium had a dual blood supply from the conjunctival and episcleral circulations. In terms of limbal reconstruction, the engorged reperfusion vessels arose from the adjacent episcleral vessels along the limbus at 1 week postoperatively. The reconstructed MCAs had begun to appear at 1 month postoperatively and became apparent 3 months postoperatively in 26 (83.9%) of 31 eyes of the pterygium group, resulting in a successful clinical outcome. Higher vascular density and lower lacunarity were measured in the limbus and the graft at 3 months than at 1 month (P < 0.001 for all), which indicated fine reorganization of the reconstructed vessels. The pterygium had a dual blood supply, and the remodeling of the affected limbus and LCA continued up to 3 months postoperatively. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  17. Adipose-derived stem cells cultivated on electrospun l-lactide/glycolide copolymer fleece and gelatin hydrogels under flow conditions - aiming physiological reality in hypodermis tissue engineering.

    Science.gov (United States)

    Gugerell, Alfred; Neumann, Anne; Kober, Johanna; Tammaro, Loredana; Hoch, Eva; Schnabelrauch, Matthias; Kamolz, Lars; Kasper, Cornelia; Keck, Maike

    2015-02-01

    Generation of adipose tissue for burn patients that suffer from an irreversible loss of the hypodermis is still one of the most complex challenges in tissue engineering. Electrospun materials with their micro- and nanostructures are already well established for their use as extracellular matrix substitutes. Gelatin is widely used in tissue engineering to gain thickness and volume. Under conventional static cultivation methods the supply of nutrients and transport of toxic metabolites is controlled by diffusion and therefore highly dependent on size and porosity of the biomaterial. A widely used method in order to overcome these limitations is the medium perfusion of 3D biomaterial-cell-constructs. In this study we combined perfusion bioreactor cultivation techniques with electrospun poly(l-lactide-co-glycolide) (P(LLG)) and gelatin hydrogels together with adipose-derived stem cells (ASCs) for a new approach in soft tissue engineering. ASCs were seeded on P(LLG) scaffolds and in gelatin hydrogels and cultivated for 24 hours under static conditions. Thereafter, biomaterials were cultivated under static conditions or in a bioreactor system for three, nine or twelve days with a medium flow of 0.3ml/min. Viability, morphology and differentiation of cells was monitored. ASCs seeded on P(LLG) scaffolds had a physiological morphology and good viability and were able to migrate from one electrospun scaffold to another under flow conditions but not migrate through the mesh. Differentiated ASCs showed lipid droplet formations after 21 days. Cells in hydrogels were viable but showed rounded morphology. Under flow conditions, morphology of cells was more diffuse. ASCs could be cultivated on P(LLG) scaffolds and in gelatin hydrogels under flow conditions and showed good cell viability as well as the potential to differentiate. These results should be a next step to a physiological three-dimensional construct for soft tissue engineering and regeneration. Copyright © 2014

  18. A case of keratitis associated with limbal relaxing incision

    Directory of Open Access Journals (Sweden)

    Aravind Haripriya

    2016-01-01

    Full Text Available We report a case of keratitis associated with limbal relaxing incision (LRI. The patient presented with progressive loss of vision with best-corrected visual acuity 20/40. Immature cataract with 1.43D against the rule astigmatism was noted. Prophylactic topical antibiotic was administered before surgery. He underwent uneventful phacoemulsification with intraocular lens implantation with LRI. On the 33rd postoperative day (POD, he presented with infiltrate along LRI site with mild iritis. Corneal scraping was positive for Staphylococcus aureus. After the treatment with topical moxifloxacin and fortified cefazolin, the infiltrate started to resolve. On the 50th POD, the corneal infection was resolved with marked thinning at LRI site.

  19. A case of keratitis associated with limbal relaxing incision

    Science.gov (United States)

    Haripriya, Aravind; Smita, Anand

    2016-01-01

    We report a case of keratitis associated with limbal relaxing incision (LRI). The patient presented with progressive loss of vision with best-corrected visual acuity 20/40. Immature cataract with 1.43D against the rule astigmatism was noted. Prophylactic topical antibiotic was administered before surgery. He underwent uneventful phacoemulsification with intraocular lens implantation with LRI. On the 33rd postoperative day (POD), he presented with infiltrate along LRI site with mild iritis. Corneal scraping was positive for Staphylococcus aureus. After the treatment with topical moxifloxacin and fortified cefazolin, the infiltrate started to resolve. On the 50th POD, the corneal infection was resolved with marked thinning at LRI site. PMID:28112139

  20. 小鼠表皮干细胞的分离与培养%Isolation and Cultivation of Mouse Epidermal Stem Cells

    Institute of Scientific and Technical Information of China (English)

    王丽娟; 孙耀兰; 杨雪; 王友亮; 杨晓

    2011-01-01

    Objective: To isolate and culture the mouse epidermal stem cells and analyze its capability of clone formation for further studies.Methods: The neonate mice epidermal basal cells were digested by dispase and trypsin and then seeded directly and cultivated in culture flasks without any feeder cells.The epidermal stem cells were identified by K15 and α6-integrin staining and their clone formation abilities were evaluated when they were co-cultured with mouse embryonic fibrolasts feeder cells in a cell differentiation condition.Results: The clones of neonate mice epidermal stem cells were successfully formated after 2~3 day's cultivation characterized by low nucleo-cytoplasma ratio and tiny and round shape.Those cells could be specialized marked with K15 and α6-integrin after cell passage.Conclusion: The cultivation and passage of mouse epidermal stem cells can be achieved using this kind of method.%目的:探讨体外分离和培养小鼠表皮干细胞和分析表皮干细胞克隆形成能力的方法.方法:采用中性蛋白酶和胰酶消化新生小鼠表皮基底层细胞,将细胞直接接种在细胞瓶中,在无滋养层条件下培育;利用表皮干细胞标记物K15和α6整联蛋白进行免疫荧光鉴定;以小鼠胚胎成纤维细胞作为滋养层与成年小鼠角质细胞共培养,进而分析表皮干细胞的克隆形成能力.结果:新生小鼠表皮干细胞克隆在培养2~3 d后开始形成,细胞核质较小,细胞呈小而圆的形态特征;传代后的细胞可以被K15和α6整联蛋白特异性标记.结论:利用该方法能够实现对小鼠表皮干细胞的体外培养和传代.

  1. Influence of oxygen in the cultivation of human mesenchymal stem cells in simulated microgravity: an explorative study

    NARCIS (Netherlands)

    S. Versari; J. Klein-Nulend; J. van Loon; S. Bradamante

    2013-01-01

    Previous studies indicated that human Adipose Tissue-derived Mesenchymal Stem Cells (AT-MSCs) cultured in simulated microgravity (sim-μg) in standard laboratory incubators alter their proliferation and differentiation. Recent studies on the stem cell (SC) niches and the influence of oxygen on SC pro

  2. Isolation of mesenchymal stem cells from human bone and long-term cultivation under physiologic oxygen conditions.

    Science.gov (United States)

    Klepsch, Sebastian; Jamnig, Angelika; Trimmel, Daniela; Schimke, Magdalena; Kapferer, Werner; Brunauer, Regina; Singh, Sarvpreet; Reitinger, Stephan; Lepperdinger, Günter

    2013-01-01

    Bone-derived stroma cells contain a rare subpopulation, which exhibits enhanced stemness characteristics. Therefore, this particular cell type is often attributed the mesenchymal stem cell (MSC). Due to their high proliferation potential, multipotential differentiation capacity, and immunosuppressive properties, MSCs are now widely appreciated for cell therapeutic applications in a multitude of clinical aspects. In line with this, maintenance of MSC stemness during isolation and culture expansion is considered pivot. Here, we provide step-by-step protocols which allow selection for, and in vitro propagation of high quality MSC from human bone.

  3. [Genetic and physiological compatibility of different forms of stem eelworms. VI. The crossing of eelworms from cultivated plants and weeds].

    Science.gov (United States)

    Ladygina, N M

    1978-01-01

    The crossing of stem eelworms of onion and red clover with these from Cirsium setosum and Taraxacum officinale resulted in the fertilization of females, egglaying and embriogenesis. However, the hybrid eggs died, as a rule. Only in one experiment a large population developed up to F5 but few hybrids survived to F10. The studied stem eelworms of weeds are genetically non-compatible with Ditylenchus dipsaci of onion and red clover and are distinct species.

  4. Evaluation of a new disposable silicon limbal relaxing incision knife by experienced users

    Directory of Open Access Journals (Sweden)

    Parvu Valentin

    2009-12-01

    Full Text Available Abstract Background Previous research has suggested that the silicon BD Atomic Edge™ knife has superior performance characteristics when compared to a metal knife and performance similar to diamond knife when making various incisions. This study was designed to determine whether a silicon accurate depth knife has equivalent performance characteristics when compared to a diamond limbal relaxing incision (LRI knife and superior performance characteristics when compared to a steel accurate depth knife when creating limbal relaxing incision. Methods Sixty-five ophthalmic surgeons with limbal relaxing incision experience created limbal relaxing incisions in ex-vivo porcine eyes with silicon and steel accurate depth knives and diamond LRI knives. The ophthalmic surgeons rated multiple performance characteristics of the knives on Visual Analog Scales. Results The observed differences between the silicon knife and diamond knife were found to be insignificant. The mean ratio between the performance of the silicon knife and the diamond knife was shown to be greater than 90% (with 95% confidence. The silicon knife's mean performance was significantly higher than the performance of the steel knife for all characteristics. (p-value Conclusions For experienced users, the silicon accurate depth knife was found to be equivalent in performance to the diamond LRI knife and superior to the steel accurate depth knife when making limbal relaxing incisions in ex vivo porcine eyes. Disposable silicon LRI knives may be an alternative to diamond LRI knives.

  5. From Folklore to Molecular Pharmacophores: Cultivating STEM Students among Young, First-Generation Female Mexican-Americans

    Science.gov (United States)

    Gardea, Jessica; Rios, Laura; Pal, Rituraj; Gardea-Torresdey, Jorge L.; Narayan, Mahesh

    2011-01-01

    The Research and Engineering Apprenticeship Program of the Academy of Applied Science has funded several high school student summer internships to work within the Department of Chemistry at the University of Texas at El Paso. Over the last nine years, young Mexican-American scholars have been recruited into STEM-specific (science, technology,…

  6. The Preliminary Experimental Study of Induced Differentiation of Embryonic Stem Cells into Corneal Epithelial Cells

    Institute of Scientific and Technical Information of China (English)

    Ling Yu; Jian Ge; Zhichong Wang; Bing Huang; Keming Yu; Chongde Long; Xigu Chen

    2001-01-01

    Purpose:To study preliminarily induced differentiation of embryonic stem cells intocorneal epithelial cells in vitro.Methods: Murine embryonic stem cells were co-cultured with Rabbit limbal cornealepithelial cells in Transwell system to induce differentiation. Mophological andimmunohistochemical examination were implemented.Results: The induced cells from embryonic stem cells have an epithelial appearance.The cells formed a network and were confluent into film gradually after beingco-cultured with rabbit limbal corneal epithelial cells for 24 ~ 96 hours. The cells rangedmosaic structure and localized together with clear rim. Most of the cells showedpolygonal appearance. Transmission electron microscope showed lots of microvilli on thesurface of induced cells and tight junctions between them. These epithelial-like cellsexpressed the corneal epithelial cell specific marker cytokeratin3/cytokeratinl2.Conclusion: The potential mechanism of the differentiation of murine embryonic stemcells into corneal epithelial cells induced by limbal corneal epithelial cell-derivedinducing activity is to be further verified.

  7. In vitro cultivation of human fetal pancreatic ductal stem cells and their differentiation into insulin-producing cells

    Institute of Scientific and Technical Information of China (English)

    Zhong-Xiang Yao; Mao-Lin Qin; Jian-Jun Liu; Xing-Shu Chen; De-Shan Zhou

    2004-01-01

    AIM: To isolate, culture and identify the human fetal pancreatic ductal stem cells in vitro, and to observe the potency of these multipotential cells differentiation into insulin-producing cells.METHODS: The human fetal pancreas was digested by 1 g/L collagease type Ⅳ and then 2.5 g/L trypsin was used to isolate the pancreatic ducta stem cells, followed by culture in serum-free, glucose-free DMEM media with some additional chemical substrates in vitro (according to the different Stage). The cells were induced by glucose-free (control),5 mmol/L, 17.8 mmol/L and 25 mmol/L glucose, respectively.The cell types of differentiated cells were identified using immunocytochemical staining.RESULTS: The shape of human fetal pancreatic ductal stem cells culturedin vitro was firstly fusiform in the first 2 wk,and became monolayer and cobblestone pattern after another 3 to 4 wk. After induced and differentiated by the glucose of different concentrations for another 1 to 2 wk,the cells formed the pancreatic islet-like structures. The identification and potency of these cells were then identified by using the pancreatic ductal stem cell marker, cytokeratin-19 (CK-19), pancreatic β cell marker, insulin and pancreatic α cell marker, glucagons with immunocytochemical staining.At the end of the second week, 95.2% of the cells were positive for CK-19 immunoreactivity. Up to 22.7% of the cells induced by glucose were positive for insulin immunoreactivity, and less than 3.8% of the cells were positive for glucagon immunoreactivity in pancreatic isletlike structures. The positive ratio of immunoreactive staining was dependent on the concentration of glucose, and it was observed that the 17.8 mmol/L glucose stimulated effectively to produce insulin- and glucagons-producing cells.CONCLUSION: The human fetal pancreatic ductal stem cells are capable of proliferation in vitro. These cells have multidifferentiation potential and can be induced by glucose and differentiated into insulin

  8. Human mesenchymal stem cell expression program upon extended ex-vivo cultivation, as revealed by 2-DE-based quantitative proteomics.

    Directory of Open Access Journals (Sweden)

    Andreia Madeira

    Full Text Available Human mesenchymal stem cells (MSC have been on the focus of intense clinical-oriented research due to their multilineage differentiation potential and immunomodulatory properties. However, to reach the clinically meaningful cell numbers for cellular therapy and tissue engineering applications, MSC ex-vivo expansion is mandatory but sequential cell passaging results in loss of proliferative, clonogenic and differentiation potential. To get clues into the molecular mechanisms underlying cellular senescence resulting from extended ex-vivo cultivation of bone marrow (BM MSC, we explored a two-dimensional gel electrophoresis (2-DE based quantitative proteomics to compare the expression programs of Passage 3 cells (P3, commonly used in clinical studies with expanded MSC, and Passage 7 (P7 cells, which already demonstrated significant signs of culture-induced senescence. Proteins of the functional categories "Structural components and cellular cytoskeleton" and "Folding and stress response proteins" are less abundant in P7 cells, compared to P3, while proteins involved in "Energy metabolism", "Cell cycle regulation and aging" and "Apoptosis" are more abundant. The large number of multiple size and charge isoforms with an altered content that were identified in this study in P7 versus P3, namely the cytoskeleton components β-actin (7 forms and vimentin (24 forms, also emphasizes the importance of post-transcriptional modification upon long-term cultivation. The differential protein expression registered suggests that cellular senescence occurring during ex-vivo expansion of BM MSC is associated with the impairment of cytoskeleton remodeling and/or organization and the repair of damaged proteins resulting from cell exposure to culture stress. The genome-wide expression approach used in this study has proven useful for getting mechanistic insights into the observed decrease on the proliferative and clonogenic potential of P7 versus P3 cells and paves the

  9. Human mesenchymal stem cell expression program upon extended ex-vivo cultivation, as revealed by 2-DE-based quantitative proteomics.

    Science.gov (United States)

    Madeira, Andreia; da Silva, Cláudia L; dos Santos, Francisco; Camafeita, Emilio; Cabral, Joaquim M S; Sá-Correia, Isabel

    2012-01-01

    Human mesenchymal stem cells (MSC) have been on the focus of intense clinical-oriented research due to their multilineage differentiation potential and immunomodulatory properties. However, to reach the clinically meaningful cell numbers for cellular therapy and tissue engineering applications, MSC ex-vivo expansion is mandatory but sequential cell passaging results in loss of proliferative, clonogenic and differentiation potential. To get clues into the molecular mechanisms underlying cellular senescence resulting from extended ex-vivo cultivation of bone marrow (BM) MSC, we explored a two-dimensional gel electrophoresis (2-DE) based quantitative proteomics to compare the expression programs of Passage 3 cells (P3), commonly used in clinical studies with expanded MSC, and Passage 7 (P7) cells, which already demonstrated significant signs of culture-induced senescence. Proteins of the functional categories "Structural components and cellular cytoskeleton" and "Folding and stress response proteins" are less abundant in P7 cells, compared to P3, while proteins involved in "Energy metabolism", "Cell cycle regulation and aging" and "Apoptosis" are more abundant. The large number of multiple size and charge isoforms with an altered content that were identified in this study in P7 versus P3, namely the cytoskeleton components β-actin (7 forms) and vimentin (24 forms), also emphasizes the importance of post-transcriptional modification upon long-term cultivation. The differential protein expression registered suggests that cellular senescence occurring during ex-vivo expansion of BM MSC is associated with the impairment of cytoskeleton remodeling and/or organization and the repair of damaged proteins resulting from cell exposure to culture stress. The genome-wide expression approach used in this study has proven useful for getting mechanistic insights into the observed decrease on the proliferative and clonogenic potential of P7 versus P3 cells and paves the way to set

  10. [Dendrobium officinale stereoscopic cultivation method].

    Science.gov (United States)

    Si, Jin-Ping; Dong, Hong-Xiu; Liao, Xin-Yan; Zhu, Yu-Qiu; Li, Hui

    2014-12-01

    The study is aimed to make the most of available space of Dendrobium officinale cultivation facility, reveal the yield and functional components variation of stereoscopic cultivated D. officinale, and improve quality, yield and efficiency. The agronomic traits and yield variation of stereoscopic cultivated D. officinale were studied by operating field experiment. The content of polysaccharide and extractum were determined by using phenol-sulfuric acid method and 2010 edition of "Chinese Pharmacopoeia" Appendix X A. The results showed that the land utilization of stereoscopic cultivated D. officinale increased 2.74 times, the stems, leaves and their total fresh or dry weight in unit area of stereoscopic cultivated D. officinale were all heavier than those of the ground cultivated ones. There was no significant difference in polysaccharide content between stereoscopic cultivation and ground cultivation. But the extractum content and total content of polysaccharide and extractum were significantly higher than those of the ground cultivated ones. In additional, the polysaccharide content and total content of polysaccharide and extractum from the top two levels of stereoscopic culture matrix were significantly higher than that of the ones from the other levels and ground cultivation. Steroscopic cultivation can effectively improves the utilization of space and yield, while the total content of polysaccharides and extractum were significantly higher than that of the ground cultivated ones. The significant difference in Dendrobium polysaccharides among the plants from different height of stereo- scopic culture matrix may be associated with light factor.

  11. Monolayer cultivation of osteoprogenitors shortens duration of the embryonic stem cell test while reliably predicting developmental osteotoxicity.

    Science.gov (United States)

    zur Nieden, Nicole I; Davis, Lesley A; Rancourt, Derrick E

    2010-11-09

    Osteotoxic compounds administered during pregnancy can initiate skeletal congenital anomalies in the embryo. In vitro, developmental osteotoxicity of a compound can be predicted with the embryonic stem cell test (EST), the only in vitro embryotoxicity model identified to date that entirely abrogates the use of animals. Although the previously identified endpoint osteocalcin mRNA expression robustly predicts developmental osteotoxicity, it can only be assayed after 5 weeks of in vitro culture with existing embryoid body (EB)-based differentiation protocols. Therefore, the goal of this study was to characterize novel earlier endpoints of developmental osteotoxicity for the EST. The currently used EB-based differentiation protocol was modified so that a monolayer culture of pre-differentiated cells was inoculated. The expression profile of five bone-specific mRNAs, including osteocalcin, over the course of 30 differentiation days suggested an acceleration of pre-osteoblast specification in the monolayer over the EB-based protocol. Similarly, calcification was already visible after 14 days of culture in monolayer cultures. Employing image and absorption-based techniques to measure the degree of mineralization in these cells after compound treatment, the three compounds Penicillin G, 5-fluorouracil (5-FU) and all-trans retinoic acid (RA) were then tested after 14 days in monolayer cultures and compared to embryoid body-based differentiations at day 30. By modifying the culture the three test substances were classified correctly into non- or strong osteotoxic. Moreover, we were successful in shortening the assay duration from 30 to 14 days.

  12. In vitro cultivation of rat bone marrow mesenchymal stem cells and establishment of pEGFP/Ang-1 transfection method

    Institute of Scientific and Technical Information of China (English)

    Xiu-Qun Zhang; Long Wang; Shu-Li Zhao; Wei Xu

    2014-01-01

    Objective:To obtain the bone marrow mesenchymal stem cells (BMSCs), complete phenotypic identification and successfully transfect rat BMSCs by recombinant plasmid pEGFP/Ang-1. Methods:BMSCs were isolated from bone marrow using density gradient centrifugation method and adherence screening method, and purified. Then the recombinant plasmid pEGFP/Ang-1 was used to transfect BMSCs and the positive clones were obtained by the screen of G418 and observed under light microscopy inversely. Green fluorescent exhibited by protein was enhanced to measure the change time of the expression amount of Ang-1. Results: BMSCs cell lines were obtained successfully by adherence screening method and density gradient centrifugation. Ang-1 recombinant plasmid was transfected smoothly into rat BMSCs, which can express Ang-1 for 3 d and decreased after 7 d. Conclusions:Adherence screening method and density gradient centrifugation can be effective methods to obtain BMSCs with high purity and rapid proliferation. Besides, the expression of transfected recombinant plasmid pEGFP/Ang-1 in rat BMSCs is satisfactory.

  13. Comparison between Limbal and Pars Plana Approaches Using Microincision Vitrectomy for Removal of Congenital Cataracts with Primary Intraocular Lens Implantation

    Science.gov (United States)

    Liu, Xin; Zheng, Tianyu; Zhou, Xingtao; Lu, Yi; Zhou, Peng; Fan, Fan; Luo, Yi

    2016-01-01

    Purpose. To compare the surgical outcomes of limbal versus pars plana vitrectomy using the 23-gauge microincision system for removal of congenital cataracts with primary intraocular lens implantation. Methods. We retrospectively reviewed all eyes that underwent cataract removal through limbal or pars plana incision. Main outcome measures included visual outcomes and complications. Results. We included 40 eyes (26 patients) in the limbal group and 41 eyes (30 patients) in the pars plana group. The mean age was 46 months. There was no significant difference in best-corrected visual acuity between the two groups (P = 0.64). Significantly, more eyes had at least one intraoperative complication in the limbal group than in the pars plana group (P = 0.03) that were mainly distributed at 1.5–3 years of age (P = 0.01). The most common intraoperative complications were iris aspiration, iris prolapse, and iris injury. More eyes in the limbal group had postoperative complications and required additional intraocular surgery, but the difference was not significant (P = 0.19). Conclusions. The visual results were encouraging in both approaches. We recommend the pars plana approach for lower incidence of complications. The limbal approach should be reserved for children older than 3 years of age and caution should be exercised to minimize iris disturbance. PMID:27313872

  14. Limbal Fibroblasts Maintain Normal Phenotype in 3D RAFT Tissue Equivalents Suggesting Potential for Safe Clinical Use in Treatment of Ocular Surface Failure.

    Science.gov (United States)

    Massie, Isobel; Dale, Sarah B; Daniels, Julie T

    2015-06-01

    Limbal epithelial stem cell deficiency can cause blindness, but transplantation of these cells on a carrier such as human amniotic membrane can restore vision. Unfortunately, clinical graft manufacture using amnion can be inconsistent. Therefore, we have developed an alternative substrate, Real Architecture for 3D Tissue (RAFT), which supports human limbal epithelial cells (hLE) expansion. Epithelial organization is improved when human limbal fibroblasts (hLF) are incorporated into RAFT tissue equivalent (TE). However, hLF have the potential to transdifferentiate into a pro-scarring cell type, which would be incompatible with therapeutic transplantation. The aim of this work was to assess the scarring phenotype of hLF in RAFT TEs in hLE+ and hLE- RAFT TEs and in nonairlifted and airlifted RAFT TEs. Diseased fibroblasts (dFib) isolated from the fibrotic conjunctivae of ocular mucous membrane pemphigoid (Oc-MMP) patients were used as a pro-scarring positive control against which hLF were compared using surrogate scarring parameters: matrix metalloproteinase (MMP) activity, de novo collagen synthesis, α-smooth muscle actin (α-SMA) expression, and transforming growth factor-β (TGF-β) secretion. Normal hLF and dFib maintained different phenotypes in RAFT TE. MMP-2 and -9 activity, de novo collagen synthesis, and α-SMA expression were all increased in dFib cf. normal hLF RAFT TEs, although TGF-β1 secretion did not differ between normal hLF and dFib RAFT TEs. Normal hLF do not progress toward a scarring-like phenotype during culture in RAFT TEs and, therefore, may be safe to include in therapeutic RAFT TE, where they can support hLE, although in vivo work is required to confirm this. dFib RAFT TEs (used in this study as a positive control) may be useful toward the development of an ex vivo disease model of Oc-MMP.

  15. Evaluation of a new disposable silicon limbal relaxing incision knife by experienced users

    OpenAIRE

    Parvu Valentin; Dugue Geoffrey; Albanese John; Bajart Ann M; Lee Edwin

    2009-01-01

    Abstract Background Previous research has suggested that the silicon BD Atomic Edge™ knife has superior performance characteristics when compared to a metal knife and performance similar to diamond knife when making various incisions. This study was designed to determine whether a silicon accurate depth knife has equivalent performance characteristics when compared to a diamond limbal relaxing incision (LRI) knife and superior performance characteristics when compared to a steel accurate dept...

  16. Surgical procedure for limbal dermoid and palpebral coloboma-dermoid in English bulldog puppy

    Directory of Open Access Journals (Sweden)

    Božinović Stanko

    2009-01-01

    Full Text Available A dermoid is a malformation, a congenital choristoma, in fact an ectopic part of the skin. This malformation can be located on the eyelids (palpebral, on the palpebral or bulbar part of the conjunctive, on the third eyelid or on the cornea, the limbus edge of the eyelid. Ocular dermoids consist of a cornified squamous-stratified epithelium that can be pigmented to various degrees, located on irregular dermis in which there are hair follicles, sweat and fat glands, and, in rare cases, cartilage and bone can also be observed. Corneal dermoids can be classified into three types: limbal or epibulbar dermoid, a dermoid which covers the greater part or the entire cornea, a dermoid that covers the entire front segment of the eye. Coloboma presents a congenital malformation that is characterized by the absence of an eyelid and it can be located on the upper or on the lower lid. This paper presents the case of an English bulldog puppy in which a limbal dermoid and a palpebral coloboma-dermoid were observed at the same time. In this case, superficial keratectomy was selected for the treatment of the limbal dermoid, while the palpebral colobomadermoid was treated using excision with a plastic reconstruction procedure. A microscopic examination of sample tissue of the corneal demoid showed, on the surface, cornified squamous-stratified epithelium lying on the dermis. The dermis was observed to contain hair follicles, as well as sweat and fat glands.

  17. MMSC-LIKE LIMBAL CELLS COTRANSPLANTATION PROMOTES LOCAL IMMUNOCORRECTION AND CORNEAL GRAFT TRANSPARENT RETENTION IN HIGH RISK KERATOPLASTY

    Directory of Open Access Journals (Sweden)

    S. A. Borzenok

    2014-01-01

    Full Text Available Aim was to evaluate clinical results of donor corneal graft survival in high-risk recipients in co-transplantation of preserved allogenic limbal grafts. Materials and methods. Two types of penetrative keratoplasties were carried out in patients with corneal graft opacities and high risk of rejection (n = 69. Co-transplantation of donor cornea and allogenic MMSC-like limbal cells in the form of limbal transplants was carried out in the 1st group (n = 36; in the 2nd group (n = 33 only the cornea was transplanted. Results. Observation of the patients during one year after surgery showed that the rate of transparent cornea engraftment increased in the 1st group (86,1 against 69,7% in the 2nd group. The density of endothelial cells was also higher in the 1st group (85,9 against 76,2% in the 2nd group. At the same time, progressive decreasing of pro-inflammatory cytokines (IL-6, IFNγ, TNFα and increasing of anti-inflammatory cytokines (IL-10, IL-1RA, TGFβ along with higher level of HLA-G5 were revealed in the recipients’ tear fluid in the 1st group in comparison to the 2nd group. Conclusion. Simultaneous transplantation of preserved limbal grafts with corneal graft in high-risk keratoplasty favors the transparent cornea engraftment, obviously, this is due to immunoregulatory activity of the MMSC-like limbal cells. 

  18. Experimental study on cultivation and purification of bone marrow-derived mesenchymal stem cells and its co-culture with chitosan porous scaffolds in vitro

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    Feng YAN

    2014-12-01

    Full Text Available Background As commonly used scaffold material in tissue engineering, chitosan has many advantages, such as strong biodegradability, low antigenicity, good biocompatibility and no pyrogen reaction. This study aims to isolate, cultivate and purify Sprague-Dawley (SD rat bone marrow-derived mesenchymal stem cells (BMSCs, and to observe the growth of BMSCs when co-cultured with self-made chitosan porous scaffold in vitro and to test the biocompatibility of this tissue engineering scaffold, so as to lay the foundation for promoting nerve regeneration of transplant treatment.  Methods Three-week-old healthy male SD rats were used in this study, and BMSCs were isolated and purified through bone marrow adherent culture method. The surface markers of BMSCs at Passage 3 were detected and identified by flow cytometry (FCM and the BMSCs were three?dimensionally cultured in vitro on chitosan porous scaffolds produced by freeze-drying method. Ethanol alternative method was used to detect the chitosan scaffold porosity. Scanning electron microscope was used to explore the internal structure of the scaffold, measure the size of its aperture, and observe the morphology and development of the cells within the scaffold. Methyl thiazolyl tetrazolium (MTT method was used to determine the cells' proliferation.  Results The cultured BMSCs were uniform and similiar to fibrous arrangement, and mixed cells reduced obviously. The identification result of FCM showed the CD29 positive rate was 98.49% and CD45RA positive rate was only 0.85%. The chitosan scaffold had an interlinked, uniform similar three-dimensional porous structure and its aperture porosity was 90%. Some cells stretched out pseudopod and infiltrated into the porous structure of scaffold, even fusing with them. The BMSCs were seeded in the scaffold successfully. The chitosan scaffold had no obvious effect on BMSCs' proliferation. Conclusions Chitosan porous scaffolds have good structural character and

  19. Cytokeratin patterns in corneal, limbal, and conjunctival epithelium. An immunofluorescence study with PKK-1, 8.12, 8.60, and 4.62 anticytokeratin antibodies.

    Science.gov (United States)

    Ryder, M I; Weinreb, R N

    1990-11-01

    The authors examined immunofluorescently the specific cytokeratin staining patterns of corneal, limbal, and conjunctival epithelium with PKK-1, 8.12, 4.62, and 8.60 monoclonal anticytokeratin antibodies. Observations were made on unfixed frozen postmortem human tissue. The PKK-1 antibody stain was observed in all layers of corneal epithelium but only in suprabasal layers of limbal and conjunctival epithelium. By contrast, the 8.12 antibody stain was observed only in the superficial layer of corneal epithelium but through all layers of limbal and conjunctival epithelium. The 4.60 antibody stain was seen in focal areas of corneal and limbal epithelium and through all layers of conjunctival epithelium. The 8.60 antibody stain was not present in the three epithelia. These immunofluorescence studies showed unique cytokeratin patterns among layers in corneal, limbal, and conjunctival epithelium.

  20. Results of Limbal Conjunctival Autograft Transplantation in Primary and Recurrent Pterygium Surgery

    Directory of Open Access Journals (Sweden)

    Raşit Kılıç

    2014-12-01

    Full Text Available Objectives: To evaluate the results of limbal conjunctival autograft transplantation in cases with primary and recurrent pterygium. Materials and Methods: A total of 54 eyes of 49 patients who were operated for pterygium with limbal conjunctival autograft technique between April 2011-July 2013 with at least 6 months of follow-up were retrospectively assessed. All cases were distributed into 3 groups according to the postoperative therapy and the primary/recurrent nature of pterygium: Recurrent pterygium with postoperative topical cyclosporin A+hydroxypropylmethylcellulose treatment were included in group 1, primary pterygium with postoperative topical cyclosporin A+hydroxypropylmethylcellulose were included in group 2, and primary pterygium without either topical cyclosporin A or hydroxypropylmethylcellulose were included in group 3. Results: Eleven eyes of 9 patients were detected for group 1, 11 eyes of 11 patients for group 2, and 32 eyes of 29 patients were detected for group 3. Follow-up period was 17±9.1 months for group 1, 14.4±6.1 months for group 2, 13.2±7 months for group 3, and 14.2±7.3 months for all groups. Totally, two recurrences (3.7% were observed as one case for both group 1 (9.1% and group 3 (3.1% during the follow-up period. The recurrence rate between the three groups was not statistically significantly different (p=0.653. Conclusion: Limbal conjunctival autograft technique is an effective and safe technique in excision of primary and recurrent pterygium. (Turk J Ophthalmol 2014; 44: 449-53

  1. Rethinking immunological privilege: implications for corneal and limbal stem cell transplantation.

    Science.gov (United States)

    Williams, K A; Coster, D J

    1997-11-01

    Immunological privilege operates within the normal eye by multiple passive and active mechanisms, including antigen sequestration, maintenance of an immunosuppressive local environment and induction of apoptotic death in infiltrating cells of the immune system. Ocular privilege might have developed to protect the eye from the collateral damage associated with an inflammatory response to invading pathogens. Nevertheless, corneal grafts do undergo irreversible immunological rejection and, furthermore, corneal graft rejection is very similar at a histological level to the rejection processes that operate in vascularized organ grafts. Ocular privilege is thus relative. The question arises as to how corneal grafts are rejected in the face of so many mechanisms designed to prevent immune responses from operating inside the eye--a question that is still essentially unanswered.

  2. Clinical observation on fibrin glue technique in pterygium surgery performed with limbal autograft transplantation

    Directory of Open Access Journals (Sweden)

    Hui Liu

    2013-07-01

    Full Text Available AIM: To compare the efficiency and safety of fibrin glue to suture technique in pterygium surgery performed with limbal autograft.METHODS: A prospective randomized clinical trial was carried out in 60 eyes of 48 patients operated for primary nasal pterygium. Autologous limbal graft taken from the superotemporal limbus was used to cover the sclera after pterygium excision under local anesthesia with 2% lidocaine. In 22 cases(30 eyes, the transplant was attached to the sclera with a fibrin tissue adhesive(group 1and in 26 cases(30 eyeswith 10-0 Virgin silk sutures(group 2. Patients were followed up at least for 3 months. Time of operation, matching degree of graft and visual analogue scale(VASscore were mainly observed and recorded. RESULTS: Patient symptoms were significantly less and biomicroscopic findings were better in group 1. Pterygium recurrence was seen in 1 case of group 1, and 1 case of group 2. Average surgery time was shorter(PCONCLUSION: Using fibrin glue for graft fixation in pterygium surgery causes significantly less postoperative pain and shortens surgery time significantly.

  3. Isolation and cultivation of rat epidermal stem cells in basal layer *%大鼠表皮基底层干细胞体外分离与培养

    Institute of Scientific and Technical Information of China (English)

    邓先见; 姚波; 李力; 徐苗苗; 顾玮; 杨策; 蒋建新

    2013-01-01

    目的建立简单、可靠的大鼠表皮基底层干细胞体外分离培养方法。方法取新生大鼠背部皮肤,采用胰酶两步消化法获得单细胞悬液,Ⅳ型胶原差速贴壁法富集干细胞,将慢黏附细胞作为对照组细胞,均以角质形成细胞无血清培养基培养。以β1-整合素和角蛋白19(K19)双重荧光染色鉴定细胞表型,克隆形成实验检测细胞体外增殖能力。结果分离培养的细胞为多角形、呈铺路石样排列,倍增时间约为24 h ,细胞形态和生长规律符合基底层干细胞的特征。免疫荧光鉴定显示细胞共表达β1-整合素和K19,基底层干细胞克隆形成能力显著强于对照细胞。结论两步消化联合Ⅳ型胶原差速贴壁法获取基底层干细胞简易可行,培养的细胞活力好、表型可靠。%Objective To establish a simple and reliable method for isolation and cultivation of epidermal stem cells from neo-natal rat skin basal layer .Methods The single cells were dissociated with twice trypsinization form neonatal rat skin .Thereafter we purified the basal layer stem cells with differential velocity adherent technique with collagen Ⅳ ,and the slow adherent cells were cultured as negative control cells .Both basal layer stem cells and control cells were cultivated with keratinocyte serum-free medium (K-sfm) .Stem cells were identified with β1-integrin and Keratin 19 by co-immunofluorescence assay ,and colony forming assay was executed to evaluate the proliferation potential of stem cells .Results The polygonal cells grew like flagstones ,with doubling time of approximately 24 hours .Both the morphology and growth properties of cells were in accordance with the character of basal layer stem cells .Co-immunofluorescence identification showed the cells were positive for the expression of β1-integrin and Keratin 19 . Basal layer stem cells had stronger clone forming ability in vitro compare with control group

  4. γδ T Cells Are Necessary for Platelet and Neutrophil Accumulation in Limbal Vessels and Efficient Epithelial Repair after Corneal Abrasion

    OpenAIRE

    Li, Zhijie; Burns, Alan R.; Rumbaut, Rolando E.; Smith, C. Wayne

    2007-01-01

    Corneal epithelial abrasion in C57BL/6 mice induces an inflammatory response with peak accumulation of neutrophils in the corneal stroma within 12 hours. Platelets localize in the limbal vessels throughout the same time course as neutrophils and contribute to wound healing because antibody-dependent depletion of platelets retards epithelial division and wound closure. In the present study, T cells in the limbal epithelium were found to predominantly express the γδ T-cell receptor (TCR). Corne...

  5. The Sclerotic Scatter Limbal Arc Is More Easily Elicited under Mesopic Rather Than Photopic Conditions.

    Directory of Open Access Journals (Sweden)

    Eric Denion

    Full Text Available We aimed to determine the limbal lighting illuminance thresholds (LLITs required to trigger perception of sclerotic scatter at the opposite non-illuminated limbus (i.e. perception of a light limbal scleral arc under different levels of ambient lighting illuminance (ALI.Twenty healthy volunteers were enrolled. The iris shade (light or dark was graded by retrieving the median value of the pixels of a pre-determined zone of a gray-level iris photograph. Mean keratometry and central corneal pachymetry were recorded. Each subject was asked to lie down, and the ALI at eye level was set to mesopic values (10, 20, 40 lux, then photopic values (60, 80, 100, 150, 200 lux. For each ALI level, a light beam of gradually increasing illuminance was applied to the right temporal limbus until the LLIT was reached, i.e. the level required to produce the faint light arc that is characteristic of sclerotic scatter at the nasal limbus.After log-log transformation, a linear relationship between the logarithm of ALI and the logarithm of the LLIT was found (p<0.001, a 10% increase in ALI being associated with an average increase in the LLIT of 28.9%. Higher keratometry values were associated with higher LLIT values (p = 0.008 under low ALI levels, but the coefficient of the interaction was very small, representing a very limited effect. Iris shade and central corneal thickness values were not significantly associated with the LLIT. We also developed a censored linear model for ALI values ≤ 40 lux, showing a linear relationship between ALI and the LLIT, in which the LLIT value was 34.4 times greater than the ALI value.Sclerotic scatter is more easily elicited under mesopic conditions than under photopic conditions and requires the LLIT value to be much higher than the ALI value, i.e. it requires extreme contrast.

  6. A Newly Defined and Xeno-Free Culture Medium Supports Every-Other-Day Medium Replacement in the Generation and Long-Term Cultivation of Human Pluripotent Stem Cells.

    Science.gov (United States)

    Ahmadian Baghbaderani, Behnam; Tian, Xinghui; Scotty Cadet, Jean; Shah, Kevan; Walde, Amy; Tran, Huan; Kovarcik, Don Paul; Clarke, Diana; Fellner, Thomas

    2016-01-01

    Human pluripotent stem cells (hPSCs) present an unprecedented opportunity to advance human health by offering an alternative and renewable cell resource for cellular therapeutics and regenerative medicine. The present demand for high quality hPSCs for use in both research and clinical studies underscores the need to develop technologies that will simplify the cultivation process and control variability. Here we describe the development of a robust, defined and xeno-free hPSC medium that supports reliable propagation of hPSCs and generation of human induced pluripotent stem cells (hiPSCs) from multiple somatic cell types; long-term serial subculturing of hPSCs with every-other-day (EOD) medium replacement; and banking fully characterized hPSCs. The hPSCs cultured in this medium for over 40 passages are genetically stable, retain high expression levels of the pluripotency markers TRA-1-60, TRA-1-81, Oct-3/4 and SSEA-4, and readily differentiate into ectoderm, mesoderm and endoderm. Importantly, the medium plays an integral role in establishing a cGMP-compliant process for the manufacturing of hiPSCs that can be used for generation of clinically relevant cell types for cell replacement therapy applications.

  7. The study of isolation, cultivation and differentiation to chondrocytic type of adiposederived stem cells%大鼠脂肪干细胞的分离培养及向软骨表型分化的实验研究

    Institute of Scientific and Technical Information of China (English)

    冯晰旻; 李晶; 王勇; 付勤

    2011-01-01

    目的 探讨从大鼠的脂肪组织中分离、培养脂肪干细胞(ADSCs)并定向诱导分化为软骨细胞的可行性.方法 取Wistar雄性大鼠脂肪组织培养,传代.并用免疫荧光法检测传代ADSCs表面抗原CD29表达.取第3代ADSCs用含有TGF-β1的培养基定向诱导培养,行Ⅱ型胶原免疫组化染色进行检测鉴定.结果 显微镜下可见脂肪干细胞的形态特点.并经免疫荧光法进行检测证实.定向诱导ADSCs向软骨细胞分化,观察细胞形态变化,并通过Ⅱ型胶原免疫组化检测,证实向表达Ⅱ型胶原的软骨细胞表型分化的可行性.结论 证实大鼠脂肪组织中存在干细胞来源细胞.并且细胞在体外培养条件下生物学性状保持稳定.通过外源性转化生长因子TGF-β定向分化、诱导、培养可表现出软骨细胞的部分特性.证实脂肪干细胞具有向软骨细胞定向分化的能力.%Objective To investigate the methods of isolation, cultivation of adipose derived stem cells (ADSCs) from the rats'adipose tissue and the feasibility of inducting differentiation to chondrocyte.Methods The adipose tissue was obtained from the wistar's male rats, and it was isolated, cultivated, and subcultured. The expression of CD29 in the subcultured ADSCs was detected by immunofluorescence. The 3rd generation ADSCs was cultured in the medium contained TGF-β, and the presence was identified by type Ⅱ collagen immunohistochemistry. Results The character of ADSCs'morphology could be observed by microscope, and it can be identified by immunofluorescence. Through the course of inducting the ADSCs to chondrocyte, the feasibility of inducting ADSCs to chondrocyte showed that type Ⅱ collagen was expressed.Conclusion We demonstrated the presence of stem cells in the adipose tissue, and the stability of biological feature in vitro. The chondrocyte could be obtained from the adipose tissue through the committed differentiation, induction, cultivation by exogenous

  8. Isolation, cultivation and identification of human fetal neural stem cells in vitro%人胎脑神经干细胞的体外分离、培养与鉴定

    Institute of Scientific and Technical Information of China (English)

    方庆; 朱庆丰; 尹国才; 陈新生

    2012-01-01

    Objective To explore the methods of isolation, cultivation and differentiation of human fetal neural stem cells, and to observe the characteristics of proliferation and differentiation of neural stem cells in vitro. Methods The neural stem cells were isolated from human fetal hippocampus at embryonic age 14 weeks by induction of labor with water bag. A serum free medium containing basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF) was used to cultured and expanded neural stem cells. The cells were cultured, passed and differentiated. Cultured and differentiated cells were identified with immunofluorescence test. Results The human neural stem cells having the abilities of self-renew and multipotency were successfully isolated and cultured from human fetal brain with serum free medium. They were found to form typical neurospheres in suspension and express Nestin antigen. The cells could be amplified and passed continuously. Neural stem cells were induced to differentiate and express specific antigens of neuron and astrocyte in serum medium. Conclusion The neural stem cells isolated from human fetal brain have the abilities of self-replication, multipotency and amplification in vitro. It has useful appliacation in further basic and clinical research.%目的 探索人胎脑神经干细胞的体外分离培养条件,从而在体外大量增殖神经干细胞,并观察神经干细胞增殖和分化的特点.方法 采用含碱性成纤维细胞生长因子(bFGF)和表皮细胞生长因子(EGF)的无血清培养技术,从14周自愿水囊引产人胎脑海马皮质中分离出神经干细胞,并进行培养、传代、分化观察,应用免疫荧光细胞化学技术对培养的细胞及其分化的细胞进行鉴定.结果 从14周人胎脑皮质中成功分离出具有自我更新和多分化潜能的神经干细胞,在无血清培养时细胞呈悬浮状态生长,形成神经球,该细胞具有连续增殖能力,可传代培养,表达神

  9. Isolation, cultivation and identification of chicken embryonic stem cells%鸡胚胎干细胞的分离、培养和鉴定

    Institute of Scientific and Technical Information of China (English)

    安静; 杜立新

    2003-01-01

    SNL cells (permanent line of irradiated mouse fibroblast cells), primary mice embryonic fibroblasts (PMEF)cells and primary chicken embryonic fibroblasts (PCEF) cells were respectively used as the feeder cells for chicken embryonic stem cell culture. The isolated blastoderm cells from the stage X embryos of chicken were cultured in Dulercco' s Modified Eagle Medium (DMEM) supplemented with leukemia inhibitory factor (LIF, 1 000 IU/ml), basic fibroblast growth factor (bFGF 10 ng/ml) and stem cell factor (SCF, 5 ng/ml). The alkaline phosphatase (AKP) test, differentiation experiment in vitro and chimeric chicken production were carried out. The resuts showed that culture on feeder layer of PMEF yielded high quality CES cell colonies. The shape of typical CES clone showed as follows: nested aggregation (clone) with clear edge and round surface as well as close arrangement within the clone. Strong positive AKP reactive cells were observed. On the other hand, the fourth passage CES cells could differentiate into various cells in the absence of feeder layer cells and LIF in vitro. The third and fourth passage cells were injected into the subgerminal cavity of recipient embryos at stage X. The manipulated embryos were incubated until hatching. Of 269 Hailan embryos injected with CES cells of Shouguang Chickens, 8.2% (22/269) survived to hatching, 3 feather chimeras had been produced, which suggests that an effective culture systems were established and it could promote the growth of CES cells and maintain them in an undifferentiated state.

  10. Study of epithelial differentiation and protein expression of keratinocyte-mesenchyme stem cell co-cultivation on electrospun nylon/B. vulgaris extract composite scaffold.

    Science.gov (United States)

    Hosseinzadeh, Simzar; Soleimani, Masoud; Vossoughi, Manuchehr; Ranjbarvan, Parviz; Hamedi, Shokoh; Zamanlui, Soheila; Mahmoudifard, Matin

    2017-06-01

    Employing of the composite electrospun scaffold containing herbal extract in conjugation with co-culturing of cells can open up new window to the design of efficient biomaterials for skin tissue regeneration. Here, we introduce the synergistic effect of composite electrospun nanofibrous scaffold of nylon66 loaded with Beta vulgaris (B. vulgaris) (extract of beet roots, a plants whose widely used in Iranian folk medicine as wound healing medicine) and co-culture of mesenchymal stem-cells (MSCs)-human keratinocyte (H-keratino) differentiation towards epithelial lineage. In vitro biocompatibility was examined through MTT assay and epithelial differentiation checked by real-time PCR and immunocytochemistry (ICC) assay after co-culturing of MSCs and H-keratino on proposed scaffold. Significant enhancement in cell proliferation was detected after cell culturing on the composite type of electrospun scaffold containing B. vulgaris. Moreover, after 14days of co-culturing process, gene expression results revealed that both composite and non-composite nylon66 electrospun scaffold promote epithelial differentiation compared to mono-cell culturing of H-keratino in terms of several markers as Cytokeratin 10, Cytokeratin 14 and Involucrin and ICC of some dermal proteins like Cytokeratin 14 and Loricrin. To the best of our knowledge, findings of this study will introduce new way for the generation of novel biomaterials for the development of current skin tissue engineering. Copyright © 2017. Published by Elsevier B.V.

  11. Extracellular matrix gel is necessary for in vitro cultivation of insulin producing cells from human umbilical cord blood derived mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    GAO Feng; WU De-quan; HU Yan-hua; JIN Guang-xin

    2008-01-01

    Background Pancreatic islet cell transplantation is an effective approach to treat type 1 diabetes. However, this therapy is not widely used because of the severe shortage of transplantable donor islets. This study investigated whether mesenchymal stem cells (MSCs) derived from human umbilical cord blood (UCB) could be transdifferentiated into insulin producing cells in vitro and the role of extracellular matrix (ECM) gel in this procedure.Methods Human UCB samples were collected and MSCs were isolated. MSCs specific marker proteins were analyzed by a flow cytometer. The capacities of osteoblast and adipocyte to differentiate were tested. Differentiation into islet like cell was induced by a 15-day protocol with or without ECM gel. Pancreatic characteristics were evaluated with immunofluorescence, reverse transcription polymerase chain reaction (RT-PCR) and flow cytometry. Insulin content and release in response to glucose stimulation were detected with chemiluminescent immunoassay system.Results Sixteen MSCs were isolated from 42 term human UCB units (38%). Human UCB-MSCs expressed MSCs specific markers and could be induced in vitro into osteoblast and adipocyte. Islet like cell clusters appeared about 9 days after pancreatic differentiation in the inducing system with ECM gel. The insulin positive cells accounted for (25.2±3.4)% of the induced cells. The induced cells expressed islet related genes and hormones, but were not very responsive to glucose challenge. When MSCs were induced without ECM gel, clusters formation and secretion of functional islet proteins could not be observed.Conclusions Human UCB-MSCs can differentiate into islet like cells in vitro and ECM gel plays an important role in pancreatic endocrine cell maturation and formation of three dimensional structures.

  12. 人脐带间充质干细胞原代培养方法的改良%Improved primary cultivation of human umbilical cord mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    李小战; 马红; 许辉; 李淑; 李遇梅

    2014-01-01

    Objective:To improve the tissue mass primary culture protocol of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs),so as to explore their morphology,cell surface markers,osteogenic and adipogenic differentiation potential and observe biological properties.Methods:Human umbilical cords were obtained from healthy full-term delivered newborns.After stripping off blood vessels,the remaining connective tissues were cut into small fragments,and primary hUC-MSCs were separated by culture of traditional and improved tissue explants methods.The hUC-MSCs were tested with MTT method and the growth curves of them were drawn.Cell surface markers were detected by flow cytometry.After osteogenic and adipogenic differentiation,the potentiality of their differentiation was detected by chemistry staining.Results:After 3-4 days of incubation,flat or spindle-shaped fibroblast-like primary cells were presented,and cells reached 80% confluence after 5-6 days of incubation.Culture period was shortened by more than half.Flowing water-like or spiral growth morphology was presented after cell passage.MTT revealed high capability of proliferation.Flow cytometry analysis showed CD90 (+),CD105 (+),CD73 (+),CD166(+),CD44(+),CD29(+),positive rate of 95% or more ;CD45(-),HLA-DR(-),negative rate of not more than 2%.Its differentiation potential was proved by osteogenic and adipogenic differentiation,which was proved by chemistry staining.Conclusion:An improved primary culture method of hUCMSCs has been developed.Primary cells can be obtained from improved tissue explants method combined enzyme digestion technique.Primary cell culture time was shortened,and the efficiency of cell culture was improved.Cells isolated by the new method from the human umbilical cords had the following biological characteristics:adherent growth,high proliferation,mesenchymal stem cell phenotype,and multipotent differentiation.They could be used as the source of seed cells in scientific research and

  13. Evaluating alternative stem cell hypotheses for adultcorneal epithelial maintenance

    Institute of Scientific and Technical Information of China (English)

    John D West; Natalie J Dorà; Natalie J Dorà,

    2015-01-01

    In this review we evaluate evidence for three differenthypotheses that explain how the corneal epitheliumis maintained. The limbal epithelial stem cell (LESC)hypothesis is most widely accepted. This proposes thatstem cells in the basal layer of the limbal epithelium,at the periphery of the cornea, maintain themselvesand also produce transient (or transit) amplifying cells(TACs). TACs then move centripetally to the centre ofthe cornea in the basal layer of the corneal epitheliumand also replenish cells in the overlying suprabasallayers. The LESCs maintain the corneal epitheliumduring normal homeostasis and become more active torepair significant wounds. Second, the corneal epithelialstem cell (CESC) hypothesis postulates that, duringnormal homeostasis, stem cells distributed throughoutthe basal corneal epithelium, maintain the tissue.According to this hypothesis, LESCs are present in thelimbus but are only active during wound healing. We alsoconsider a third possibility, that the corneal epithelium ismaintained during normal homeostasis by proliferationof basal corneal epithelial cells without any input fromstem cells. After reviewing the published evidence,we conclude that the LESC and CESC hypotheses areconsistent with more of the evidence than the thirdhypothesis, so we do not consider this further. The LESCand CESC hypotheses each have difficulty accountingfor one main type of evidence so we evaluate the twokey lines of evidence that discriminate between them.Finally, we discuss how lineage-tracing experimentshave begun to resolve the debate in favour of theLESC hypothesis. Nevertheless, it also seems likely thatsome basal corneal epithelial cells can act as long-termprogenitors if limbal stem cell function is compromised.Thus, this aspect of the CESC hypothesis may have alasting impact on our understanding of corneal epithelialmaintenance, even if it is eventually shown that stemcells are restricted to the limbus as proposed by the

  14. Isolation and cultivation of keratinocyte stem-like cells from human skin dermis%人皮肤真皮组织中角朊干细胞样细胞的分离与培养*☆

    Institute of Scientific and Technical Information of China (English)

    池光范; 李美英; 赵贵芳; 邓继鸿; 刘晋宇; 李玉林

    2013-01-01

    s medium/nutrient mixture F12 (1:1) containing 1% N 2 , 2% B27, 20 μg/L epidermal growth factor, 40 μg/L basic fibroblast growth factor, and cultured at a low cel density. The isolated and cultivated cel s were analyzed by reverse transcription-polymerase chain reaction and immunofluorescence analysis. RESULTS AND CONCLUSION: The reverse transcription-polymerase chain reaction analysis showed that, the cel s isolated from dermis contained hair fol icle stem cel s expressing Lgr5 and Lirg1. The immunofluorescence analysis showed that, the cel s isolated from dermis expressed cytokeratin 8 and cytokeratin 14. After cultivated in serum-free media for 6 days, some cytokeratin 14 and integrin-α6 positive cel colonies appeared “paving stone” like morphology. The passage 1 cel s expressed keratinocyte stem cel markers, such as cytokeratin 14, CD29 and P63. The cel proliferation rate was declined with passage times and almost al cel s were terminal y differentiated at passage 3 or 4. Experimental findings indicate that, keratinocyte stem-like cel s expressing CD29, cytokeratin 14 and P63 can be successful y isolated from human skin dermis by directly cultured at a low density and in serum-free media.

  15. Isolation, cultivation, identify and cryopreservation of mesenchymal stem cells from rat adipose tissue in vitro%大鼠脂肪干细胞分离培养及细胞表型的研究

    Institute of Scientific and Technical Information of China (English)

    吕春燕; 陈高莉; 杨玲; 陈昌金; 袁慧; 杨雪梅

    2014-01-01

    Objective To search a method for isolation, cultivation, identification and cryopreservation of mesenchymal stem cells from rat adipose tissue in vitro. Method Three rats was anaesthetized and disinfected con-ventionally, their inguinal adipose tissue were taken and sheared to paste. The fragments were digested by collagenase typeⅠ, suspended by DMEM, and planted in culture dish. Then the cells were cultured in incubator culture. Their first medium change happen after 24~48 hours,then the change occur 2~3 days once again,after 5~7 days and 80%cell fu-sion, cells were digested by Trypsin and passaged by EDTA. Cell microscopy was used to morphological observation and the third generation was used to identify by flow cytometric cell cycle. Results Rats fat had a large amount of adipose-derived mesenchymal stem cells (ADMSCs). The shape of primary cultured ASCs was a star or much horn;af-ter passage of the ASCs relatively uniform shape,fusiform shape,spiral growth. The ASCs surface markers are identi-fied by flow cytometry and showed positive expression of CD44, CD106. Cryopreserved ASCs remains a good activity, high survival rate. Conclusion A simple and convenient method was successfully established to isolate, culture and store the adipose tissue derived mesenchymal stem cells, which provides the foundation for the future use of ADMSCs in the further research.%目的:分离、培养和冻存大鼠脂肪干细胞,并对其相关的细胞表型进行研究,为利用脂肪干细胞治疗梗阻性肾病肾纤维化等实验提供依据。方法取大鼠3只,经消毒麻醉,采集其腹股沟处脂肪组织分离培养其中的脂肪干细胞,用相差倒置显微镜观察细胞生长方式及形态变化。取第三代细胞用流式细胞仪作细胞免疫表型的鉴定。冻存复苏后再次检测干细胞生长情况及表型。结果大鼠脂肪组织中含有大量间充质干细胞,原代培养的ASCs呈小圆形或星形,经传代后的脂肪

  16. Classification of cultivated plants.

    NARCIS (Netherlands)

    Brandenburg, W.A.

    1986-01-01

    Agricultural practice demands principles for classification, starting from the basal entity in cultivated plants: the cultivar. In establishing biosystematic relationships between wild, weedy and cultivated plants, the species concept needs re-examination. Combining of botanic classification, based

  17. Robotics in Protected Cultivation

    NARCIS (Netherlands)

    Henten, van E.; Bac, C.W.; Hemming, J.; Edan, Y.

    2013-01-01

    This paper reviews robotics for protected cultivation systems. Based on a short description of the greenhouse crop production process, the current state in greenhouse mechanization and the challenges for robotics in protected cultivation are identified. Examples of current greenhouse robotics

  18. Long-term outcomes of limbal relaxing incisions during cataract surgery: aberrometric analysis

    Directory of Open Access Journals (Sweden)

    Monaco G

    2015-08-01

    Full Text Available Gaspare Monaco, Antonio ScialdoneDepartment of Ophthalmology, Ospedale Fatebenefratelli e Oftalmico, Milan, ItalyPurpose: To compare the final changes in corneal wavefront aberration by limbal relaxing incisions (LRIs after cataract surgery.Methods: This prospective cumulative interventional nonrandomized case study included cataract and astigmatic patients undergoing LRIs and phaco with intraocular lens implantation. LRIs were planned using Donnenfeld nomogram. The root mean square of corneal wave aberration for total Z(n,i(1≤n≤8, astigmatism Z(2,±1, coma Z(3–5–7,±1, trefoil Z(3–5–7,±2, spherical Z(4–6–8,0, and higher-order aberration (HOA Z(3≤n≤8 was examined before and 3 years after surgery (optical path difference-Scan II [OPD-Scan II]. Uncorrected distance visual acuity and best-corrected distance visual acuity (CDVA for distance, keratometric cylinder, and variations in average corneal power were also analyzed.Results: Sixty-four eyes of 48 patients were included in the study. Age ranged from 42 to 92 years (70.6±8.4 years. After LRIs, uncorrected distance visual acuity and best-corrected distance visual acuity improved statistically (P<0.01. The keratometric cylinder value decreased by 40.1%, but analysis of KP90 and KP135 polar values did not show any decrease that could be statistically confirmed (P=0.22 and P=0.24. No significant changes were detected in root mean square of total (P=0.61 and HOAs (P=0.13 aberrations. LRIs did not induce alteration in central corneal power confirming a 1:1 coupling ratio.Conclusion: LRIs determined a nonsignificant alteration of corneal HOA. Therefore, LRIs can be still considered a qualitatively viable mean in those cases where toric intraocular lenses are contraindicated or not available. Yet, the authors raise the question of nonpersonalized nomograms, as in the present study, LRIs did not reach the preset target cylinder. Keywords: astigmatism, ocular wavefront, intraocular

  19. Ocular Stem Cell Research from Basic Science to Clinical Application: A Report from Zhongshan Ophthalmic Center Ocular Stem Cell Symposium

    Directory of Open Access Journals (Sweden)

    Hong Ouyang

    2016-03-01

    Full Text Available Stem cells hold promise for treating a wide variety of diseases, including degenerative disorders of the eye. The eye is an ideal organ for stem cell therapy because of its relative immunological privilege, surgical accessibility, and its being a self-contained system. The eye also has many potential target diseases amenable to stem cell-based treatment, such as corneal limbal stem cell deficiency, glaucoma, age-related macular degeneration (AMD, and retinitis pigmentosa (RP. Among them, AMD and glaucoma are the two most common diseases, affecting over 200 million people worldwide. Recent results on the clinical trial of retinal pigment epithelial (RPE cells from human embryonic stem cells (hESCs and induced pluripotent stem cells (iPSCs in treating dry AMD and Stargardt’s disease in the US, Japan, England, and China have generated great excitement and hope. This marks the beginning of the ocular stem cell therapy era. The recent Zhongshan Ophthalmic Center Ocular Stem Cell Symposium discussed the potential applications of various stem cell types in stem cell-based therapies, drug discoveries and tissue engineering for treating ocular diseases.

  20. A new rat model of glaucoma induced by intracameral injection of silicone oil and electrocoagulation of limbal vessels

    Institute of Scientific and Technical Information of China (English)

    GUO Xue-qian; TIAN Bei; LIU Zhi-cheng; WEI Wen-bin; TAO Yong; SUN Shi-jie; ZHANG Yu

    2011-01-01

    Background A satisfied glaucoma model is absent now.The aim of this study was to evaluate the effect of a combination of intracameral injection of silicone oil and electrocoagulation of corneal limbal vessels and episcleral veins in the rats to establish glaucoma model.Methods Operation was performed in each of the left eyes of 90 adult male rats.Right eyes were used as controls.Measurement of intraocular pressure (IOP) was performed with an applanation tonometer (Tong-Pen).Retinal ganglion cells (RGCs) were retrogradely labeled by applying FluoroGold onto the bilateral superior colliculus.Results During the follow-up (24 weeks),the lOP of the study eyes was significantly higher (P<0.05) than the control eyes (at final examination,IOP of control eyes was (13.4±1.0) mmHg and lOP of study eyes was (16.1±1.8) mmHg).Correspondingly,at 24 weeks after operation,the RGCs density of the study eyes (2286.11±290.45/mm2) was significantly lower than the control eyes (2626.46±164.85/mm2,P<0.01).In the operated eyes,histological examination showed excavation of optic disc and increased neuroglial cells in the optic nerve,reduced thickness of retina and diminution of retinal ganglion cells,and atrophy of ciliary body and iris.Notably,the anterior chamber angle of the operated eye remained open.Conclusions A combination of intracameral injection of silicone oil and electrocoagulation of comeal limbal vessels and episcleral veins may establish a reliable glaucoma model for further research.

  1. Effects of different cultivation methods on stem apex yield and quality of sweetpotato for vegetable use under urban roof condition%屋顶种植条件下不同栽培方式对菜用甘薯茎尖产量及品质的影响

    Institute of Scientific and Technical Information of China (English)

    李欢; 贝嘉伟; 潘超; 赵伟东; 陆国权

    2016-01-01

    Summary Sweetpotato(Ipomoeabatatas)is an important upland crop in China,which plays an important role in feed and industrial raw materials.The root tuber has rich nutrition,and the aerial part of stems and leaves also has extremely high nutritive value.Recently,research on sweetpotato for vegetable use increased gradually.With the rapid development of urbanization process,the cultivated area decreased gradually,along with the decline in quantity and quality of agricultural products.However,the increased space of balcony and roof accelerated the development of balcony agriculture and urban roof agriculture.Meanwhile,new devices for planting become popular in daily life in cities.Sweetpotatoes grow faster in summer,and can solve the problem of leaf vegetables in short supply.Moreover,people can plant organic sweetpotato for vegetable use at home in a convenient and safe way. In this paper,three cultivation methods (soil cultivation,substrate cultivation and pipeline nutrient solution culture)and three cultivars (Pushu 53,Guangcaishu 5 and Fushu 18) of sweetpotato for vegetable use were selected for urban roof agriculture,to compare the impact of different cultivation methods on yield and quality of sweetpotato.In July 2014,stem cuttings from each of the three cultivars were planted under three cultivation methods in roof of Jixian Building in Zhejiang A & F University.Experiments were conducted in a randomized complete block design with three replications.Seedlings were examined and replanted in time after cutting to ensure a full stand of seedlings.Furthermore,control and prevention for pests should be conducted during the growth period,and sweetpotato tips (1 5 cm) were harvested after growth.The yield,water content,pigment content,soluble sugar content,soluble protein content,vitamin C content and nitrate content were determined in the lab. The results showed that the pipeline nutrient solution culture had significant advantages compared with soil cultivation or

  2. Adult stem cells: hopes and hypes of regenerative medicine.

    Science.gov (United States)

    Dulak, Józef; Szade, Krzysztof; Szade, Agata; Nowak, Witold; Józkowicz, Alicja

    2015-01-01

    Stem cells are self-renewing cells that can differentiate into specialized cell type(s). Pluripotent stem cells, i.e. embryonic stem cells (ESC) or induced pluripotent stem cells (iPSC) differentiate into cells of all three embryonic lineages. Multipotent stem cells, like hematopoietic stem cells (HSC), can develop into multiple specialized cells in a specific tissue. Unipotent cells differentiate only into one cell type, like e.g. satellite cells of skeletal muscle. There are many examples of successful clinical applications of stem cells. Over million patients worldwide have benefited from bone marrow transplantations performed for treatment of leukemias, anemias or immunodeficiencies. Skin stem cells are used to heal severe burns, while limbal stem cells can regenerate the damaged cornea. Pluripotent stem cells, especially the patient-specific iPSC, have a tremendous therapeutic potential, but their clinical application will require overcoming numerous drawbacks. Therefore, the use of adult stem cells, which are multipotent or unipotent, can be at present a more achievable strategy. Noteworthy, some studies ascribed particular adult stem cells as pluripotent. However, despite efforts, the postulated pluripotency of such events like "spore-like cells", "very small embryonic-like stem cells" or "multipotent adult progenitor cells" have not been confirmed in stringent independent studies. Also plasticity of the bone marrow-derived cells which were suggested to differentiate e.g. into cardiomyocytes, has not been positively verified, and their therapeutic effect, if observed, results rather from the paracrine activity. Here we discuss the examples of recent studies on adult stem cells in the light of current understanding of stem cell biology.

  3. Spirulina cultivation in China

    Science.gov (United States)

    Wu, Bo-Tang; Xiang, Wen-Zhou; Zeng, Cheng-Kui

    1998-03-01

    This paper reviews and discusses the development and many problems of Spirulina cultivation in China, points out the advantages and disadvantages of open photobioreactor system, and predicts that seawater Spirulina cultivation will be a new trend to be strengthened and emphasized due to its special physiological characteristics, easier management, lower fertilizer cost, and higher resistance to contaminants and rare pollution of chemicals.

  4. Reconstruction of damaged cornea by autologous transplantation of epidermal adult stem cells.

    Science.gov (United States)

    Yang, Xueyi; Moldovan, Nicanor I; Zhao, Qingmei; Mi, Shengli; Zhou, Zhenhui; Chen, Dan; Gao, Zhimin; Tong, Dewen; Dou, Zhongying

    2008-06-05

    It is crucial for the treatment of severe ocular surface diseases such as Stevens-Johnson syndrome (SJS) and ocular cicatricial pemphigoid (OCP) to find strategies that avoid the risks of allograft rejection and immunosuppression. Here, we report a new strategy for reconstructing the damaged corneal surface in a goat model of total limbal stem cell deficiency (LSCD) by autologous transplantation of epidermal adult stem cells (EpiASC). EpiASC derived from adult goat ear skin by explant culture were purified by selecting single cell-derived clones. These EpiASC were cultivated on denuded human amniotic membrane (HAM) and transplanted onto goat eyes with total LSCD. The characteristics of both EpiASC and reconstructed corneal epithelium were identified by histology and immunohistochemistry. The clinical characteristic of reconstructed corneal surface was observed by digital camera. Ten LSCD goats (10 eyes) were treated with EpiASC transplantation, leading to the restoration of corneal transparency and improvement of postoperative visual acuity to varying degrees in 80.00% (8/10) of the experimental eyes. The corneal epithelium of control groups either with HAM transplantation only or without any transplantation showed irregular surfaces, diffuse vascularization, and pannus on the entire cornea. The reconstructed corneal epithelium (RCE) expressed CK3, CK12, and PAX-6 and had the function of secreting glycocalyx-like material (AB-PAS positive). During the follow-up period, all corneal surfaces remained transparent and there were no serious complications. We also observed that the REC expressed CK1/10 weakly at six months after operation but not at 12 months after operation, suggesting that the REC was derived from grafted EpiASC. Our results showed that EpiASC repaired the damaged cornea of goats with total LSCD and demonstrated that EpiASC can be induced to differentiate into corneal epithelial cell types in vivo, which at least in part correlated with down

  5. Lisianthus cultivation using differentiated light transmission nets

    Directory of Open Access Journals (Sweden)

    Paulo Hercilio Viegas Rodrigues

    2016-08-01

    Full Text Available The Lisianthus stands out as one of the ten most cut flowers sold in the world. The use of meshes in a different light transmission is gaining more space in horticulture with promising results in greenhouse. The aim of this study was to evaluate the development of lisianthus grown in different light transmission meshes in blue, black, red and control treatments, which were transplanted 20 seedlings to cultivate Snow white with three replications, and therefore, 60 plants 240 plants per treatment in total. Agronomic characteristics such as plant height and length of the top pair of leaves were evaluated at 15, 38, 59, 82 and 105 days after transplanting. Other features such as early flowering, thick stem, distance between us and weight of the harvested stems were obtained at harvest stage. At the end of the evaluations, the treatment of red net was the most consistent with a significant difference in stem height and earliness in flowering.

  6. Amniotic membrane modulates innate immune response inhibiting PRRs expression and NF-κB nuclear translocation on limbal myofibroblasts.

    Science.gov (United States)

    Domínguez-López, Alfredo; Bautista-de Lucio, Victor Manuel; Serafín-López, Janet; Robles-Sánchez, Edson; Garfias, Yonathan

    2014-10-01

    Corneal damage observed in a viral infection such as herpetic stromal keratitis is mainly caused by proinflammatory molecules released by resident cells in the response to viral antigens. There are pattern recognition receptors like MDA5, RIG-1, and TLR3, that recognize viral dsRNA and after activation, the innate immune response is exacerbated inducing the synthesis and secretion of inflammatory cytokines through NF-κB activation. Amniotic membrane (AM) has demonstrated to reduce inflammation by several mechanisms, however the effect of AM on innate immune receptors such as MDA5, RIG-1, and TLR3 has not been reported. In this study, we have determined that the presence of AM significantly inhibited the synthesis and secretion of proinflammatory cytokines on human limbal myofibroblasts (HLM) stimulated with poly I:C. Similarly, the presence of AM reduced the protein expression of MDA5, RIG-1, and TLR3 on poly I:C stimulated HLM. Additionally, the presence of the AM significantly inhibited the NF-κB nuclear translocation when the HLM were poly I:C stimulated, and concomitantly, the AM was able to relocate cadherins affecting the myofibroblastic cellular morphology. These results suggest that AM generates an anti-inflammatory microenvironment, and specific inhibition of NFκB nuclear translocation on infected corneal tissue would reduce the inflammation undesirable effects, explaining in part the beneficial usefulness of transplanting AM on herpetic stromal keratitis.

  7. The three-dimensional organisation of the post-trabecular aqueous outflow pathway and limbal vasculature in the mouse.

    Science.gov (United States)

    van der Merwe, Elizabeth L; Kidson, Susan H

    2014-08-01

    The mouse eye has been used as a model for studies on the microanatomy of the outflow pathways but most of what is known comes from histological sections. These studies have focused mainly on the morphological features of the trabecular meshwork, Schlemm's canal and aqueous channels that link to the superficial episcleral vasculature. However, the anatomical architecture of the aqueous outflow vessels and their relationship to each other and to the general vascular circulation is not well understood. The aim of this study was to provide a detailed description of the microarchitecture of the aqueous outflow vessels and their relationship to the superficial limbal/episcleral vasculature throughout the entire limbus. The aqueous outflow vessels and blood and lymphatic vessels were imaged in PECAM-1 and LYVE-1 immunostained whole anterior segments of adult mice and three-dimensional (3-D) reconstructions of the optical sections were generated to reveal the aqueous, blood and lymphatic architecture. The arterial supply, venous drainage, organisation of perilimbal vasculature, collector channels/aqueous veins and the morphology of Schlemm's canal were revealed in their entirety and the relationships between these structures is described. Schlemm's canal was PECAM-1 positive but there was no affinity for the lymphatic marker LYVE-1. We show that Schlemm's canal is a continuous circular structure and more often seen as a single, broad, varicose vessel with short regions appearing as a plexus. Aqueous veins link Schlemm's canal to the superficial vasculature and there were no direct links seen between the canal and the lymphatic vessels.

  8. Stem Cells

    Science.gov (United States)

    Stem cells are cells with the potential to develop into many different types of cells in the body. ... the body. There are two main types of stem cells: embryonic stem cells and adult stem cells. Stem ...

  9. Corneal reconstruction by stem cells and bioengineering

    Directory of Open Access Journals (Sweden)

    Arjamaa O

    2012-09-01

    Full Text Available Olli ArjamaaDepartment of Biology, University of Turku, Turku, FinlandAbstract: Almost 300 million people are visually impaired worldwide due to various eye diseases such as cataracts, glaucoma, age-related macular degeneration, diabetic retinopathy, and corneal diseases. Notably, ten million people are blind because of severe ocular surface diseases and the majority of cases occur in developing countries. Blinding ocular surface diseases have, however, become treatable by grafting of surface layers, or by full-thickness transplantation of the cornea. As the demand for human corneal tissue for surface reconstruction and transplantation far exceeds the supply, methods are being developed to supplement tissue donation. Xenotransplantation of the cornea or cells from genetically modified pigs may become one of the solutions. Transplantation of limbal stem cells within tissue biopsies, to restore the transparency of the cornea is another remarkable method, which has shown its potential in several clinical studies. The combination of stem cell technology and engineering of biocompatible tissue equivalent, still at preclinical stage, has shown us how synthetic corneal tissue is able to guide cultured corneal stromal stem cells of human origin, to become native-like stroma, the most important layer of the cornea. These findings give hope for a large-quantity production of biomaterial for corneal reconstruction. As such, clinical ophthalmologists should become more familiar with the methods of laboratory science.Keywords: eye, grafting, keratoplasty, xenotransplantation, cell reservoir, biocompatible tissue equivalent

  10. Component analysis of cultivated ginseng, cultivated wild ginseng, and natural wild ginseng by structural parts using HPLC method

    Directory of Open Access Journals (Sweden)

    Young-Ju,Han

    2007-02-01

    Full Text Available Objectives : The aim of this experiments is to provide an objective differentiation of ginseng, Korean and Chinese cultivated wild ginseng, and natural wild ginseng through components analysis of different parts of ginseng. Methods : Comparative analyses of ginsenoside-, ginsenoside-, and ginsenosides and from the root, stem, and leaves of ginseng, Korean and Chinese cultivated wild ginseng, and natural wild ginseng were conducted using HPLC. Results : 1. For content comparison of leaves, ginseng showed highest content of ginsenoside than other samples. Natural wild ginseng showed relatively high content of ginsenosides and than other samples. 2. For content comparison of the stem, ginseng and 10 years old Chinese cultivated wild ginseng didn't contain ginsenoside . Natural wild ginseng showed higher content of ginsenosides and than other samples. 3. For content comparison of the root, ginsenoside was found only in 5 and 10 years old Korean cultivated wild ginseng. 4. Distribution of contents by the parts of ginseng was similar in ginseng and Chinese cultivated wild ginseng. Conclusions : Above experiment data can be an important indicator for the identification of ginseng, Korean and Chinese cultivated wild ginseng, and natural wild ginseng.

  11. Comparison of clinical outcomes between limbal relaxing incisions and toric intraocular lenses in eyes with astigmatic corneas

    Directory of Open Access Journals (Sweden)

    Giuliano de Oliveira Freitas

    2014-01-01

    Full Text Available Objective: To compare refractive and vectorial outcomes of limbal relaxing incisions (LRI versus toric intraocular lenses (IOL in the treatment of preexisting corneal astigmatism at the time of phacoemulsification. Methods: This longitudinal observational case series assessed 62 eyes of 31 consecutive cataract patients with preoperative corneal astigmatism between 0.75 and 2.50 diopters in both eyes. Patients were randomly assorted in two groups: one assigned to receive AcrySof Toric™ IOL in both eyes, and another one assigned to have AcrySof Natural™ IOL associated with LRI, also in both eyes. All patients were re-evaluated, postoperatively, at 1, 3 and 6 months, when refractive astigmatism analysis was performed using vectorial methods proposed by Thibos. Variability of outcomes within each group and between groups were assessed and compared. Results: Manifest refractive cylinder, in diopters (D, as means ± standard deviation, in the LRI group for 1-month, 3-month and 6-month re-evalutions were respectively -0.66 ± 0.30; -0.70 ± 0.21 and -0.74 ± 0.26 when compared to -0.58 ± 0.24; -0.63 ± 0.20, and -0.62 ± 0.17 in the toric IOL group. (p value ≥ 0.06. Vectorial analysis evidenced greater astigmatism reduction in the toric IOL group in the 6th postoperative month, when postoperative mean astigmatic power vector was 0.31 D, when compared to 0.37 D in the LRI group (p value = 0.00. Conclusions: A trend of slightly better refractive outcomes favoring toric IOL group was seen, although such a trend was not statistically significant. Vectorial analysis, however, suggests that the use of toric IOL may constitute a more advantageous approach in the treatment of pre-existing corneal astigmatism, simultaneously with phacoemulsification.

  12. Diversity of cultivated endophytic bacteria from sugarcane: genetic and biochemical characterization of Burkholderia cepacia complex isolates

    NARCIS (Netherlands)

    Mendes, R.; Pizzirani-Kleiner, A.A.; Araujo, W.L.; Raaijmakers, J.M.

    2007-01-01

    Bacteria were isolated from the rhizosphere and from inside the roots and stems of sugarcane plants grown in the field in Brazil. Endophytic bacteria were found in both the roots and the stems of sugarcane plants, with a significantly higher density in the roots. Many of the cultivated endophytic ba

  13. Diversity of cultivated endophytic bacteria from sugarcane: genetic and biochemical characterization of Burkholderia cepacia complex isolates

    NARCIS (Netherlands)

    Mendes, R.; Pizzirani-Kleiner, A.A.; Araujo, W.L.; Raaijmakers, J.M.

    2007-01-01

    Bacteria were isolated from the rhizosphere and from inside the roots and stems of sugarcane plants grown in the field in Brazil. Endophytic bacteria were found in both the roots and the stems of sugarcane plants, with a significantly higher density in the roots. Many of the cultivated endophytic

  14. Laser biomodulation on stem cells

    Science.gov (United States)

    Liu, Timon C.; Duan, Rui; Li, Yan; Li, Xue-Feng; Tan, Li-Ling; Liu, Songhao

    2001-08-01

    Stem cells are views from the perspectives of their function, evolution, development, and cause. Counterintuitively, most stem cells may arise late in development, to act principally in tissue renewal, thus ensuring an organisms long-term survival. Surprisingly, recent reports suggest that tissue-specific adult stem cells have the potential to contribute to replenishment of multiple adult tissues. Stem cells are currently in the news for two reasons: the successful cultivation of human embryonic stem cell lines and reports that adult stem cells can differentiate into developmentally unrelated cell types, such as nerve cells into blood cells. The spotlight on stem cells has revealed gaps in our knowledge that must be filled if we are to take advantage of their full potential for treating devastating degenerative diseases such as Parkinsons's disease and muscular dystrophy. We need to know more about the intrinsic controls that keep stem cells as stem cells or direct them along particular differentiation pathways. Such intrinsic regulators are, in turn, sensitive to the influences of the microenvironment, or niche, where stem cells normally reside. Both intrinsic and extrinsic signals regular stem cell fate and some of these signals have now been identified. Vacek et al and Wang et al have studied the effect of low intensity laser on the haemopoietic stem cells in vitro. There experiments show there is indeed the effect of low intensity laser on the haemopoietic stem cells in vitro, and the present effect is the promotion of haemopoietic stem cells proliferation. In other words, low intensity laser irradiation can act as an extrinsic signal regulating stem cell fate. In this paper, we study how low intensity laser can be used to regulate stem cell fate from the viewpoint of collective phototransduction.

  15. Potential Role of Induced Pluripotent Stem Cells (IPSCs for Cell-Based Therapy of the Ocular Surface

    Directory of Open Access Journals (Sweden)

    Ricardo P. Casaroli-Marano

    2015-02-01

    Full Text Available The integrity and normal function of the corneal epithelium are crucial for maintaining the cornea’s transparency and vision. The existence of a cell population with progenitor characteristics in the limbus maintains a dynamic of constant epithelial repair and renewal. Currently, cell-based therapies for bio replacement—cultured limbal epithelial transplantation (CLET and cultured oral mucosal epithelial transplantation (COMET—present very encouraging clinical results for treating limbal stem cell deficiency (LSCD and restoring vision. Another emerging therapeutic approach consists of obtaining and implementing human progenitor cells of different origins in association with tissue engineering methods. The development of cell-based therapies using stem cells, such as human adult mesenchymal or induced pluripotent stem cells (IPSCs, represent a significant breakthrough in the treatment of certain eye diseases, offering a more rational, less invasive, and better physiological treatment option in regenerative medicine for the ocular surface. This review will focus on the main concepts of cell-based therapies for the ocular surface and the future use of IPSCs to treat LSCD.

  16. Cultivating strategic thinking skills.

    Science.gov (United States)

    Shirey, Maria R

    2012-06-01

    This department highlights change management strategies that may be successful in strategically planning and executing organizational change initiatives. With the goal of presenting practical approaches helpful to nurse leaders advancing organizational change, content includes evidence-based projects, tools, and resources that mobilize and sustain organizational change initiatives. In this article, the author presents an overview of strategic leadership and offers approaches for cultivating strategic thinking skills.

  17. Cultivation of Marine Sponges.

    Science.gov (United States)

    Osinga; Tramper; Wijffels

    1999-11-01

    There is increasing interest in biotechnological production of marine sponge biomass owing to the discovery of many commercially important secondary metabolites in this group of animals. In this article, different approaches to producing sponge biomass are reviewed, and several factors that possibly influence culture success are evaluated. In situ sponge aquacultures, based on old methods for producing commercial bath sponges, are still the easiest and least expensive way to obtain sponge biomass in bulk. However, success of cultivation with this method strongly depends on the unpredictable and often suboptimal natural environment. Hence, a better-defined production system would be desirable. Some progress has been made with culturing sponges in semicontrolled systems, but these still use unfiltered natural seawater. Cultivation of sponges under completely controlled conditions has remained a problem. When designing an in vitro cultivation method, it is important to determine both qualitatively and quantitatively the nutritional demands of the species that is to be cultured. An adequate supply of food seems to be the key to successful sponge culture. Recently, some progress has been made with sponge cell cultures. The advantage of cell cultures is that they are completely controlled and can easily be manipulated for optimal production of the target metabolites. However, this technique is still in its infancy: a continuous cell line has yet to be established. Axenic cultures of sponge aggregates (primmorphs) may provide an alternative to cell culture. Some sponge metabolites are, in fact, produced by endosymbiotic bacteria or algae that live in the sponge tissue. Only a few of these endosymbionts have been cultivated so far. The biotechnology for the production of sponge metabolites needs further development. Research efforts should be continued to enable commercial exploitation of this valuable natural resource in the near future.

  18. Isolation,Cultivation and Identification of Bone Marrow Mesenchymal Stem Cells of Rats%大鼠骨髓间充质干细胞分离、培养及鉴定

    Institute of Scientific and Technical Information of China (English)

    王海峰; 陈文; 刘艳艳; 吴王泽

    2014-01-01

    目的:培养符合实验要求的大鼠骨髓间充质干细胞(bMSCs)并进行鉴定。方法采用全骨髓贴壁法培养大鼠 bMSCs,对细胞的形态及生长特性进行观察,并应用流式细胞术对细胞表面抗原 CD29、CD34、CD45、CD90表型进行鉴定。结果 bMSCs 呈贴壁生长,细胞状态良好,细胞形态以梭形为主,有时可见少量呈多角形,细胞平行排列生长或涡旋状生长;bMSCs 高表达干细胞表面抗原 CD29、CD90,而低表达造血干细胞表面抗原 CD34、CD45。结论全骨髓贴壁法培养 bMSCs 既简单又经济,通过多次传代可以达到细胞纯化的目的,对细胞的性状影响较小。%Objective To culture and identify the rat marrow mesenchymal stem cells(bMSCs)fitting the re-quirement of experimentation. Methods Whole bone marrow adherent culture method in vitro was used to culture the bMSCs of rats in vitro,the morphology and characteristics of the cells was observed,the phenotypes of CD29, CD34,CD45 and CD90 were identified by flow cytometry. Results bMSCs stuck wall growth in good condition, cells in a spindle primarily forms into fiber cell sample growth,sometimes visible small amounts of a polygonal cells,parallel arrangement growth or vortex shape growth. High expression of stem cell surface molecular(CD29 and CD90)and low expression of hematopoietic stem cell surface molecular(CD34 and CD45)were observed in the bM-SCs. Conclusion Whole bone marrow adherent culture method is simple and economical bMSCs culture method,the purified cells can be achieved through the passage,and the method has the little effect on cell trait.

  19. 毛囊细胞高效分离培养方法的建立%Establishment of High Performance Method for Isolation and Cultivation of Hair Follicle Stem Cells of Neonatal Rats

    Institute of Scientific and Technical Information of China (English)

    陈杏晔; 李凡; 刘爱军

    2014-01-01

    Objective To establish a simple , practical , highly-effective and stable method for the isolation and cultivation of rat hair follicle cells. Methods Under sterile condition, single hair follicle was taken out after the skin around the barbel of SD neonatal rats was sheared off. And then the hair follicles were digested with two-step method with Type Ⅰcollagenase and trypsin. The obtained cell suspension was planted into the culture plate which was covered with extracellular matrix, and then was cultivated with K-SFM culture medium containing fetal bovine serum with volume fraction of 1%. On the next day, K-SFM culture medium was replaced with serum-free culture medium. The remaining tissues were cut into pieces and spread out in the culture flask, and then were cultivated with HG-DMEM culture medium containing serum. Two kinds of cells were harvested and then were identified by immunofluorescence. The hair follicle epithelial cells were tested by flow cytometer. Results The hair follicle epithelial cells obtained through the above methods showed rapid adherence, and were round or polygon-like , with typical cobblestone-like morphology. The long spindle-shaped cells were seen around the tissues cultivated, having many protrusions on the surface of the cells, and they were interconnected into reticular structure. The expression of cytokeratin 15, cytokeratin 19 and β1 integrin in epithelial cells were positive. Most of the epithelial cells were in the G1 phase, accounting for 75.6%. The expression of laminin ( LN), fibronectin ( FN) and vimentin in the connective tissue sheath cells were also positive. Conclusion The cells harvested by modified two-step enzyme digestion method have confirmed as hair follicle cells and fibroblasts, and the obtained cells are of rapid adherence, good homogeneity, and active proliferation.%【目的】建立一种简单易行、高效稳定、细胞活性好的毛囊细胞分离培养方法。【方法】无菌条件下剪下SD乳

  20. Corneal stem cells and tissue engineering: Current advancesand future perspectives

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Major advances are currently being made in regenerativemedicine for cornea. Stem cell-based therapiesrepresent a novel strategy that may substituteconventional corneal transplantation, albeit there aremany challenges ahead given the singularities of eachcellular layer of the cornea. This review recapitulatesthe current data on corneal epithelial stem cells,corneal stromal stem cells and corneal endothelialcell progenitors. Corneal limbal autografts containingepithelial stem cells have been transplanted in humansfor more than 20 years with great successful rates,and researchers now focus on ex vivo cultures andother cell lineages to transplant to the ocular surface.A small population of cells in the corneal endotheliumwas recently reported to have self-renewal capacity,although they do not proliferate in vivo . Two mainobstacles have hindered endothelial cell transplantationto date culture protocols and cell delivery methods tothe posterior cornea in vivo . Human corneal stromalstem cells have been identified shortly after therecognition of precursors of endothelial cells. Stromalstem cells may have the potential to provide a directcell-based therapeutic approach when injected tocorneal scars. Furthermore, they exhibit the ability todeposit organized connective tissue in vitro and maybe useful in corneal stroma engineering in the future.Recent advances and future perspectives in the field arediscussed.

  1. [Karyotypes of the stem eelworms from wild-growing plants].

    Science.gov (United States)

    Barabashova, V N

    1979-01-01

    Unlike the stem eelworms of cultivated plants, which have n = 12, the stem eelworms of wild plants (Picris sp., Taraxacum officinale, Hieracium pratense, H. pilosella, Cirsium setosum and Falcaria vulgaris) possess high chromosomal numbers (from n = 19 in the first to n = 28 in the latter). Due to this the stem eelworms of wild plants must be separated from the collective species Ditylenchus dipsaci. Apparently these forms of stem eelworms are distinct species polyploid in their origin.

  2. Therapeutic potentials of human embryonic stem cells in Parkinson's disease

    National Research Council Canada - National Science Library

    Newman, Mary B; Bakay, Roy A E

    2008-01-01

    .... The isolation, differentiation, and long-term cultivation of human embryonic stem cells and the therapeutic research discovery made in relation to the beneficial properties of neurotrophic and neural...

  3. Feeding and Development of Emerald Ash Borer (Coleoptera: Buprestidae) on Cultivated Olive, Olea europaea.

    Science.gov (United States)

    Cipollini, Don; Rigsby, Chad M; Peterson, Donnie L

    2017-08-01

    We examined the suitability of cultivated olive, Olea europaea L., as a host for emerald ash borer, Agrilus planipennis Fairmaire. In a bioassay using cut stems from a field-grown olive tree (cv. 'Manzanilla') we found that 45% of larvae that had emerged from eggs used to inoculate stems, were recovered alive, many as larvae or prepupae, during periodic debarking of a subset of stems. Three intact stems that 19 larvae successfully entered were exposed to a simulated overwintering treatment. Four live adults emerged afterwards, and an additional pupa and several prepupae were discovered after debarking these stems. Cultivated olive joins white fringetree as one of the two species outside of the genus Fraxinus capable of supporting the development of emerald ash borer from neonate to adult. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. Use of a Toric Intraocular Lens and a Limbal-Relaxing Incision for the Management of Astigmatism in Combined Glaucoma and Cataract Surgery

    Science.gov (United States)

    Gibbons, Allister

    2016-01-01

    Purpose We report the surgical management of a patient with glaucoma undergoing cataract surgery with high preexisting astigmatism. A combination of techniques was employed for her astigmatism management. Methods A 76-year-old female with 5.5 dpt of corneal astigmatism underwent surgery in her left eye consisting of one-site trabeculectomy, phacoemulsification, toric intraocular lens implantation and a single inferior limbal-relaxing incision. Results Intraocular pressure control was achieved with no medication at 11 mm Hg; before the filtering procedure, the pressure was 16 mm Hg on two topical drugs. Astigmatism was reduced to 0.75 dpt, and both corrected and uncorrected visual acuity improved. Conclusions Astigmatism management can have a good outcome in combined procedures. We encourage surgeons to address astigmatism in the preoperative planning of patients undergoing glaucoma surgery associated with phacoemulsification. PMID:27293408

  5. Effect of Microgravity Rotating Culture System on Mesenchymal Stem Cells' Cultivation%微重力旋转培养系统对骨髓间充质干细胞分化增殖的影响

    Institute of Scientific and Technical Information of China (English)

    蒋淳; 霍建忠; 冯振洲; 陈峥嵘

    2005-01-01

    目的:观察模拟微重力旋转培养系统(RCCS)对骨髓间充质干细胞(mesenchymal stem cells,MSCs)体外培养的影响.方法:将兔MSCs与三维载体PGA相复合后,置于RCCS系统中进行培养,观察MSCs增殖能力和超微结构的变化.结果:经过RCCS系统培养,MSCs增殖能力明显增强,细胞形态较静置培养组更接近生理情况.结论:采用RCCS系统进行细胞/载体结合物的体外培养,增殖能力有明显增强,细胞的形态更接近生理状态,有助于培养出接近正常软骨生物学特性的工程化软骨.

  6. Co-cultivation of keratinocyte-human mesenchymal stem cell (hMSC) on sericin loaded electrospun nanofibrous composite scaffold (cationic gelatin/hyaluronan/chondroitin sulfate) stimulates epithelial differentiation in hMSCs: In vitro study.

    Science.gov (United States)

    Bhowmick, Sirsendu; Scharnweber, Dieter; Koul, Veena

    2016-05-01

    Fortifying the scaffold with bioactive molecules and glycosaminoglycans (GAGs), is an efficient way to design new generation tissue engineered biomaterials. In this study, we evaluated the synergistic effect of electrospun nanofibrous composite scaffold (cationic gelatin/hyaluronan/chondroitin sulfate) loaded with sericin and, contact co-culture of human mesenchymal stem cells (hMSCs)-keratinocytes on hMSCs' differentiation towards epithelial lineage. Cationic gelatin is prepared with one step novel synthesis process by grafting quaternary ammonium salts to the backbone of gelatin. Release kinetics studies showed that Fickian diffusion is the major release mechanism for both GAGs and sericin/gelatin. In vitro biocompatibility of the electrospun scaffold was evaluated in terms of LDH and DNA quantification assay on human foreskin fibroblast, human keratinocyte and hMSC. Significant proliferation (∼ 4-6 fold) was detected after culturing all three cell on the electrospun scaffold containing sericin. After 5 days of contact co-culture, results revealed that electrospun scaffold containing sericin promote epithelial differentiation of hMSC in terms of several protein markers (keratin 14, ΔNp63α and Pan-cytokeratin) and gene expression of some dermal proteins (keratin 14, ΔNp63α). Findings of this study will foster the progress of current skin tissue engineering scaffolds by understanding the skin regeneration and wound healing process.

  7. Glass bead cultivation of fungi

    DEFF Research Database (Denmark)

    Droce, Aida; Sørensen, Jens Laurids; Giese, H.

    2013-01-01

    Production of bioactive compounds and enzymes from filamentous fungi is highly dependent on cultivation conditions. Here we present an easy way to cultivate filamentous fungi on glass beads that allow complete control of nutrient supply. Secondary metabolite production in Fusarium graminearum...... and Fusarium solani cultivated on agar plates, in shaking liquid culture or on glass beads was compared. Agar plate culture and glass bead cultivation yielded comparable results while liquid culture had lower production of secondary metabolites. RNA extraction from glass beads and liquid cultures was easier...... to specific nutrient factors. •Fungal growth on glass beads eases and improves fungal RNA extraction....

  8. 土壤改良对平地栽参人参茎叶总皂苷含量的影响%Effects of Different Soil Improvement Treatment on Total Saponins Content in Stem and Leaf of Panax ginseng Cultivated in Farmland Soil

    Institute of Scientific and Technical Information of China (English)

    尹敏晶; 赵岩; 张连学

    2012-01-01

    Total saponin of ginseng {Panax ginseng C.A.Mey) stem and leaf was taken as an index to appraise and atudy the best proposal of soil improvement treatment. Effects of different combination of maize straw, stool of pig, stool of deer, antagonistic bacteria and spent mushroom substrate on total saponin content of ginseng stem and leaf were studied by using quadratic regression and orthogonal rotation as fundamental mathematic model. The Model Analysis showed that under the same cultivation conditions, the contribution of five substrates to ginseng saponin content ranking from the largest to the smallest was pig manure, deer dung, corn stalks, waste materials from fungal and antagonistic bacteria. Computer similated selection showed that when the application dosage of maize straw was 6.64 kg/m2, stool of pig was 3.24 kg/m2, stool of deer was 3.48 kg/m2, antagonistic bacteria was 6.87 g/m2, spent mushroom substrate was 7.02 kg/m2, the predictive value of total saponin of ginseng stem and leaf was 17.81%. In. Conclusion the assemblage of these cultivation factors could be recommended as a program of planting ginseng on farmland soil.%以人参(Panax ginseng C.A.Mey)茎叶总皂苷为评价指标,研究平地栽参不同土壤改良的最优方案.试验以二次回归正交旋转设计为基本数学模型,研究玉米秸秆、猪粪、鹿粪、拮抗菌、菌糠5种基质的不同组合对人参茎叶总皂苷含量的影响.模型解析发现,在相同的栽培条件下,5种基质对人参茎叶总皂苷含量的贡献从大到小为猪粪、鹿粪、玉米秸秆、菌糠、拮抗菌.计算机模拟寻优表明,玉米秸秆施用量6.64kg/m2,猪粪施用量3.24 kg/m2,鹿粪施用量3.48 kg/m2,拮抗菌施用量6.87 g/m2,菌糠施用量7.02 kg/m2条件下,人参茎叶总皂苷含量预测值为17.81%.综上这些栽培因素的组合可以作为平地栽培人参的推荐方案.

  9. Optimization of Isolation and Cultivation of Rat Bone Marrow Mesenchymal Stem Cells%大鼠骨髓间充质干细胞分离与培养条件的优化研究

    Institute of Scientific and Technical Information of China (English)

    晏丹; 舒赛男

    2008-01-01

    目的:建立和优化大鼠骨髓间充质干细胞(mesenchymal stem cells,MSCs)的分离培养条件,以获得群体均一、未分化状态保持良好的MSCs.方法:收集不同周龄大鼠骨髓细胞;以不同浓度Percoll密度梯度离心分离骨髓单个核细胞;以60%低糖DMEM40%MCDB201为基础培养基,培养24h去悬浮细胞;以不同接种密度传代培养;碱性磷酸酶染色和油红O染色考察MSCs向骨和脂肪组织分化的潜能.结果:采用57%Percoll液的分离效果优于70%Percoll液.6周龄(体重约180g)大鼠能在细胞分离的质和量上达到最佳效果.24h进行悬浮细胞去除、5×103/cm2接种密度传代培养,光镜和电镜显示MSCs增殖能力强,功能状态活跃,成脂成骨实验显示多向分化潜能保持良好.结论:优化大鼠周龄、分离液的密度、细胞培养条件及改进培养方法有助于获得多向分化潜能保持良好的均一的MSCs.

  10. Plant growth and cultivation.

    Science.gov (United States)

    Podar, Dorina

    2013-01-01

    There is a variety of methods used for growing plants indoor for laboratory research. In most cases plant research requires germination and growth of plants. Often, people have adapted plant cultivation protocols to the conditions and materials at hand in their own laboratory and growth facilities. Here I will provide a guide for growing some of the most frequently used plant species for research, i.e., Arabidopsis thaliana, barley (Hordeum vulgare) and rice (Oryza sativa). However, the methods presented can be used for other plant species as well, especially if they are related to the above-mentioned species. The presented methods include growing plants in soil, hydroponics, and in vitro on plates. This guide is intended as a starting point for those who are just beginning to work on any of the above-mentioned plant species. Methods presented are to be taken as suggestive and modification can be made according to the conditions existing in the host laboratory.

  11. Micrometeorological principles of protected cultivation

    Science.gov (United States)

    Protected cultivation is a broad term commonly used among producers of specialty crops. Techniques can range from complex fixed structures to field site selection, to straightforward cultural practices in the field. This introduction to the ASHS workshop "Protected cultivation for fruit crops" consi...

  12. "Logistic analysis of algae cultivation"

    NARCIS (Netherlands)

    Slegers, P.M.; Leduc, S.; Wijffels, R.H.; Straten, van G.; Boxtel, van A.J.B.

    2015-01-01

    Energy requirements for resource transport of algae cultivation are unknown. This work describes the quantitative analysis of energy requirements for water and CO2 transport. Algae cultivation models were combined with the quantitative logistic decision model ‘BeWhere’ for the regions Benelux

  13. Production of deuterated switchgrass by hydroponic cultivation.

    Science.gov (United States)

    Evans, Barbara R; Bali, Garima; Foston, Marcus; Ragauskas, Arthur J; O'Neill, Hugh M; Shah, Riddhi; McGaughey, Joseph; Reeves, David; Rempe, Caroline S; Davison, Brian H

    2015-07-01

    The bioenergy crop switchgrass was grown hydroponically from tiller cuttings in 50 % D 2 O to obtain biomass with 34 % deuterium substitution and physicochemical properties similar to those of H 2 O-grown switchgrass controls. Deuterium enrichment of biological materials can potentially enable expanded experimental use of small angle neutron scattering (SANS) to investigate molecular structural transitions of complex systems such as plant cell walls. Two key advances have been made that facilitate cultivation of switchgrass, an important forage and biofuel crop, for controlled isotopic enrichment: (1) perfusion system with individual chambers and (2) hydroponic growth from tiller cuttings. Plants were grown and maintained for several months with periodic harvest. Photosynthetic activity was monitored by measurement of CO2 in outflow from the growth chambers. Plant morphology and composition appeared normal compared to matched controls grown with H2O. Using this improved method, gram quantities of switchgrass leaves and stems were produced by continuous hydroponic cultivation using growth medium consisting of basal mineral salts in 50 % D2O. Deuterium incorporation was confirmed by detection of the O-D and C-D stretching peaks with FTIR and quantified by (1)H- and (2)H-NMR. This capability to produce deuterated lignocellulosic biomass under controlled conditions will enhance investigation of cell wall structure and its deconstruction by neutron scattering and NMR techniques.

  14. Bone marrow cells differentiation into organ cells using stem cell therapy.

    Science.gov (United States)

    Yang, Y-J; Li, X-L; Xue, Y; Zhang, C-X; Wang, Y; Hu, X; Dai, Q

    2016-07-01

    Bone marrow cells (BMC) are progenitors of bone, cartilage, skeletal tissue, the hematopoiesis-supporting stroma and adipocyte cells. BMCs have the potential to differentiate into neural cells, cardiac myocytes, liver hepatocytes, chondrocytes, renal, corneal, blood, and myogenic cells. The bone marrow cell cultures from stromal and mesenchymal cells are called multipotent adult progenitor cells (MAPCs). MAPCs can differentiate into mesenchymal cells, visceral mesoderm, neuroectoderm and endoderm in vitro. It has been shown that the stem cells derived from bone marrow cells (BMCs) can regenerate cardiac myocytes after myocardial infarction (MI). Adult bone marrow mesenchymal stem cells have the ability to regenerate neural cells. Neural stem/progenitor cells (NS/PC) are ideal for treating central nervous system (CNS) diseases, such as Alzheimer's, Parkinson's and Huntington disease. However, there are important ethical issues about the therapeutic use of stem cells. Neurons, cardiac myocytes, hepatocytes, renal cells, blood cells, chondrocytes and adipocytes regeneration from BMCs are very important in disease control. It is known that limbal epithelial stem cells in the cornea can repair the eye sight and remove symptoms of blindness. Stem cell therapy (SCT) is progressing well in animal models, but the use of SCT in human remains to be explored further.

  15. Cultivo primário de células epiteliais germinativas do limbo de olhos doadores Culture of limbal stem cells of donor eyes

    OpenAIRE

    Lima Fabiana Amorim de; D'Angelo Magaly; Miranda II Homero Augusto de; Felberg Sérgio; Nishiwaki-Dantas Maria Cristina; Dantas Paulo Elias Correa

    2003-01-01

    OBJETIVO: Padronizar cultivo primário de células epiteliais germinativas do limbo de olhos doadores do Banco de Olhos da Santa Casa de São Paulo. MÉTODOS: Por meio de biópsias de aproximadamente 4 mm² realizadas na região do limbo cirúrgico do anel córneo-escleral remanescente de olhos doadores, foram obtidos explantes, que passaram por métodos de dissociação para obtenção de células epiteliais germinativas do limbo, as quais foram semeadas em placas de cultivo celulare encubadasna estufa a 3...

  16. 人羊水间充质干细胞分离培养方法的优化%Optimization of the isolation and cultivation method of human amniotic fluid-derived mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    郭素红; 苑春华; 侯毅鞠; 刘会玲

    2011-01-01

    背景:目前关于人羊水间充质干细胞的体外分离培养方法不一,获得较多数量的间充质干细胞仍有困难.目的:分离80份羊水标本,比较不同的体外培养方法,优化筛选到一种合适的培养纯化条件,为人羊水间充质干细胞的基础研究和临床广泛应用奠定基础.方法:无菌条件下采集足月分娩和终止妊娠引产的羊水,分离羊水细胞,比较孕期、不同培养基、接种密度、首次换液时间对人羊水间充质干细胞原代培养过程的影响,通过细胞化学染色方法检测细胞代谢情况,观察人羊水间充质干细胞的生物学特性.结果与结论:相同培养条件下,采用AmnioMAXⅡcomplete羊水专用细胞培养基,以5×104/cm2 的密度接种,首次换液时间为6 d时,人羊水间充质干细胞原代培养成功率较高.孕期为14~20周的人羊水间充质干细胞培养成功率高于晚期妊娠(21~36周)及足月分娩(37~42周)的羊水.人羊水间充质干细胞强表达过碘酸-雪夫、酸性磷酸酶、酸性α-醋酸萘酚酯酶染色,弱表达中性粒细胞碱性磷酸酶,不表达过氧化酶、苏丹黑染色.提示,优化筛选到一种合适的人羊水间充质干细胞培养纯化条件.%BACKGROUND: There are different methods of in vitro isolating culture for human amniotic fluid-derived mesenchymal stem cells (AF-MSCs). To gain most AF-MSCs is still difficult.OBJECTIVE: We had isolated 80 cases AF, and compared different in vitro culture methods for optimization and bolted a better method to establish foundation of AF-MSCs in clinical widespread application.METHODS: Amniotic fluid was collected from full-term deliveries and artificial labors under aseptic condition. The amniotic fluid cells were isolated by centrifugation. The influences of different pregnancy ages, culture media, incubation densities and the time points of the first medium change on the growth of AF-MSCs were analyzed. The cell metabolism was

  17. Isolation and Cultivation of Anaerobes

    DEFF Research Database (Denmark)

    Aragao Börner, Rosa

    2016-01-01

    Anaerobic microorganisms play important roles in different biotechnological processes. Their complex metabolism and special cultivation requirements have led to less isolated representatives in comparison to their aerobic counterparts.In view of that, the isolation and cultivation of anaerobic...... microorganisms is still a promising venture, and conventional methodologies as well as considerations and modifications are presented here. An insight into new methodologies and devices as well as a discussion on future perspectives for the cultivation of anaerobes may open the prospects of the exploitation...

  18. Fruit protected cultivation in China

    Institute of Scientific and Technical Information of China (English)

    Gao Huajun; Wang Saoming; Wang Jiaxi

    2003-01-01

    Protected fruit cultivation in China has developed very quickly from the early 1990s, and now it is animportant branch in fruit cultivation. A brief review including fruit species, developing history, growing area, output, anddistribution in the whole country is made in the paper. Characteristics of the dominant kinds of greenhouse,environmental control methods, and standards of temperature, humidity, light and CO2 for different fruit species arepresented. Information on varieties, growing benefits, special management practices and other aspects of the main fruitspecies used for protected cultivation are also presented.

  19. Types of Stem Cells

    Science.gov (United States)

    ... Stem Cell Glossary Search Toggle Nav Types of Stem Cells Stem cells are the foundation from which all ... Learn About Stem Cells > Types of Stem Cells Stem cells Stem cells are the foundation for every organ ...

  20. 以小鼠骨髓间充质干细胞为饲养层分离培养胚胎干细胞的研究%The Study of Using Bone Marrow Mesenchymal Stem Cells of Mouse as Feeder Layer Cells in Cultivation of Embryonic Stem Cells

    Institute of Scientific and Technical Information of China (English)

    杨恕玲; 单守明; 何生虎

    2011-01-01

    为了探求一种更简单有效地分离培养昆明小鼠胚胎千细胞的饲养层培养体系,实验中收集3.5天的昆明小鼠胚胎,接种于小鼠骨髓问充质干细胞的饲养层培养体系,来分离培养胚胎干细胞.结果在骨髓间充质干细胞的饲养层培养体系上,获得了典型的ES细胞样集落,经碱性磷酸酶染色呈阳性,且具有分化的潜能.实验结果表明,小鼠骨髓间充质干细胞可以作为饲养层来分离培养ES细胞,并且能保持ES细胞的体外未分化状态.%In order to find the more simple method of prepartion for the layer feeder cells, the blastocytes of 3.5 days embryo of Kunming mouse cultured on bone marrow mesenchymal stem cells were used to isolate and culture the ES cells. The colonies of ES cells were harvested to passage. The growth of stem cells identified was observed, and their biological vitality was determined by alkaline phosphatase activity assay and cell differentiation examination. The blastocytes of 3.5 days embryo from Km mouse could be cultured on the mouse bone marrow mesenchymal stem cells to develop into ES ceils with maintenance of undifferentiated state in vitro.

  1. Formation and cultivation of medaka primordial germ cells.

    Science.gov (United States)

    Li, Zhendong; Li, Mingyou; Hong, Ni; Yi, Meisheng; Hong, Yunhan

    2014-07-01

    Primordial germ cell (PGC) formation is pivotal for fertility. Mammalian PGCs are epigenetically induced without the need for maternal factors and can also be derived in culture from pluripotent stem cells. In egg-laying animals such as Drosophila and zebrafish, PGCs are specified by maternal germ plasm factors without the need for inducing factors. In these organisms, PGC formation and cultivation in vitro from indeterminate embryonic cells have not been possible. Here, we report PGC formation and cultivation in vitro from blastomeres dissociated from midblastula embryos (MBEs) of the fish medaka (Oryzias latipes). PGCs were identified by using germ-cell-specific green fluorescent protein (GFP) expression from a transgene under the control of the vasa promoter. Embryo perturbation was exploited to study PGC formation in vivo, and dissociated MBE cells were cultivated under various conditions to study PGC formation in vitro. Perturbation of somatic development did not prevent PGC formation in live embryos. Dissociated MBE blastomeres formed PGCs in the absence of normal somatic structures and of known inducing factors. Most importantly, under culture conditions conducive to stem cell derivation, some dissociated MBE blastomeres produced GFP-positive PGC-like cells. These GFP-positive cells contained genuine PGCs, as they expressed PGC markers and migrated into the embryonic gonad to generate germline chimeras. Our data thus provide evidence for PGC preformation in medaka and demonstrate, for the first time, that PGC formation and derivation can be obtained in culture from early embryos of medaka as a lower vertebrate model.

  2. Much Improved Water Use Efficiency of Rice under Non-Flooded Mulching Cultivation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Water shortage is increasingly limiting the luxury use of water in rice cultivation. In this study, non-flooded mulching cultivation of rice only consumed a fraction of the water that was needed for traditional flooded cultivation and largely maintained the grain yield. We also investigated the growth and development of rice plants and examined grain yield formation when rice was subjected to non-flooded mulching cultivation. One indica hybrid rice combination was grown in a field experiment and three cultivation methods, traditional flooding (TF), non-flooded straw mulching cultivation (SM) and non-flooded plastic mulching cultivation (PM), were conducted during the whole season. Grain yield showed that there was no significant difference between SM and TF rice, but the grain yield of SM cultivation was significantly higher than that of PM. The tiller numbers were inhibited in the early stage under non-flooded mulching cultivation, but the situation was reversed at the later period. Both SM and PM rice reduced dry matter accumulation of shoot, but increased root dry weight,enhanced the remobilization of assimilates from stems to grains and increased the harvest index. During the middle and later grain filling period, mulched plants showed a faster decrease in chlorophyll concentrations, photosynthetic rates of flag leaves and root activity than TF rice, indicating that non-flooded mulching cultivation enhanced plant senescence. In comparison, SM treatment produced higher grain yield and, more dry matter accumulation and panicle numbers than the PM treatment. The overall results suggest that high yield of non-flooded mulching cultivation of rice can be achieved with much improved irrigational water use efficiency.

  3. Engineering considerations for process development in mammalian cell cultivation.

    Science.gov (United States)

    Zhang, Hu; Wang, Weixiang; Quan, Chunshan; Fan, Shengdi

    2010-01-01

    Mammalian cell cultivation plays a great role in producing protein therapeutics in the last decades. Many engineering parameters are considered for optimization during process development in mammalian cell cultivation, only shear and mixing are especially highlighted in this paper. It is believed that shear stress due to agitation has been over-estimated to damage cells, but shear may result in nonlethal physiological responses. There is no cell damage in the regions where bubbles form, break up and coalescence, but shear stress becomes significant in the wake of rising bubbles and causes great damage to cells in bubble burst regions. Mixing is not sufficient to provide homogeneous dissolved oxygen tension, pH, CO2 and nutrients in large-scale bioreactors, which can bring severe problems for cell growth, product formation and process control. Scale-down reactors have been developed to address mixing and shear problems for parallel operations. Engineering characterization in conventional and recently developed scale-down bioreactors has been briefly introduced. Process challenges for cultivation of industrial cell lines in high cell densities as well as cultivation of stem cells and other human cells for regenerative medicine, tissue engineering and gene therapy are prospected. Important techniques, such as micromanipulation and nanomanipulation (optical tweezers) for single cell analysis, computational fluid dynamics (CFD) for shear and mixing characterization, and miniaturized bioreactors, are being developed to address those challenges.

  4. Bioreactor cultivation of anatomically shaped human bone grafts.

    Science.gov (United States)

    Temple, Joshua P; Yeager, Keith; Bhumiratana, Sarindr; Vunjak-Novakovic, Gordana; Grayson, Warren L

    2014-01-01

    In this chapter, we describe a method for engineering bone grafts in vitro with the specific geometry of the temporomandibular joint (TMJ) condyle. The anatomical geometry of the bone grafts was segmented from computed tomography (CT) scans, converted to G-code, and used to machine decellularized trabecular bone scaffolds into the identical shape of the condyle. These scaffolds were seeded with human bone marrow-derived mesenchymal stem cells (MSCs) using spinner flasks and cultivated for up to 5 weeks in vitro using a custom-designed perfusion bioreactor system. The flow patterns through the complex geometry were modeled using the FloWorks module of SolidWorks to optimize bioreactor design. The perfused scaffolds exhibited significantly higher cellular content, better matrix production, and increased bone mineral deposition relative to non-perfused (static) controls after 5 weeks of in vitro cultivation. This technology is broadly applicable for creating patient-specific bone grafts of varying shapes and sizes.

  5. CUTTING BACK THE STEM: CULTIVATING LIBERAL ARTS IN OFFICER ACCESSIONS

    Science.gov (United States)

    2016-06-01

    waged in the mind. The future officer corps must use critical, divergent thinking in order to assess a strategic environment, appreciate its...is ill suited to the current complex security environment. Tactical and operational effects are vital, but at the strategic level, war is waged in...a ceiling of only 7,700 feet, a bomb load of just over 1,000 pounds, and top speed of 98 miles per hour.31 The B-9 and B-10 brought incremental

  6. Stem Cells

    Directory of Open Access Journals (Sweden)

    Madhukar Thakur

    2015-02-01

    Full Text Available Objective: The objective of this presentation is to create awareness of stem cell applications in the ISORBE community and to foster a strategy of how the ISORBE community can disseminate information and promote the use of radiolabeled stem cells in biomedical applications. Methods: The continued excitement in Stem Cells, in many branches of basic and applied biomedical science, stems from the remarkable ability of stem cells to divide and develop into different types of cells in the body. Often called as Magic Seeds, stem cells are produced in bone marrow and circulate in blood, albeit at a relatively low concentration. These virtues together with the ability of stem cells to grow in tissue culture have paved the way for their applications to generate new and healthy tissues and to replace diseased or injured human organs. Although possibilities of stem cell applications are many, much remains yet to be understood of these remarkable magic seeds. Conclusion: This presentation shall briefly cover the origin of stem cells, the pros and cons of their growth and division, their potential application, and shall outline some examples of the contributions of radiolabeled stem cells, in this rapidly growing branch of biomedical science

  7. Differentiation and molecular profiling of human embryonic stem cell-derived corneal epithelial cells.

    Science.gov (United States)

    Brzeszczynska, J; Samuel, K; Greenhough, S; Ramaesh, K; Dhillon, B; Hay, D C; Ross, J A

    2014-06-01

    It has been suggested that the isolation of scalable populations of limbal stem cells may lead to radical changes in ocular therapy. In particular, the derivation and transplantation of corneal stem cells from these populations may result in therapies providing clinical normality of the diseased or damaged cornea. Although feasible in theory, the lack of donor material in sufficient quantity and quality currently limits such a strategy. A potential scalable source of corneal cells could be derived from pluripotent stem cells (PSCs). We developed an in vitro and serum-free corneal differentiation model which displays significant promise. Our stepwise differentiation model was designed with reference to development and gave rise to cells which displayed similarities to epithelial progenitor cells which can be specified to cells displaying a corneal epithelial phenotype. We believe our approach is novel, provides a robust model of human development and in the future, may facilitate the generation of corneal epithelial cells that are suitable for clinical use. Additionally, we demonstrate that following continued cell culture, stem cell-derived corneal epithelial cells undergo transdifferentiation and exhibit squamous metaplasia and therefore, also offer an in vitro model of disease.

  8. Cultivation and uses of cucurbits

    Science.gov (United States)

    Cultivated cucurbits have spread through trade and exploration from their respective Old and New World centers of origin to the six arable continents and are important in local, regional and world trade. Cucumber (Cucumis sativus L.), melon (Cucumis melo L.), pumpkin, squash and gourd (Cucurbita spp...

  9. Cultivating archives: meanings and identities

    NARCIS (Netherlands)

    E. Ketelaar

    2012-01-01

    By cultivating archives through successive activations, people and communities define their identities. In these activations, the meanings of archives are constructed and reconstructed. Archives are not a static artifact imbued with the record creator’s voice alone, but a dynamic process involving a

  10. The Dynamics of Intensive Cultivation

    OpenAIRE

    Christian Bidard

    2008-01-01

    An increase in the demand for agricultural goods leads to the use of more intensive cultivation methods. Though Ricardo sees no difficulties in the intensification process, their existence is revealed by the possible occurrence of multiple equilibria. A general theory of intensive rent is based on a formal parallel with single-product systems without land.

  11. On the Cultivation of Intensive Reading Skills

    Institute of Scientific and Technical Information of China (English)

    杨雪琴

    2008-01-01

    This paper concerns the importance of the cultivation of reading skills,the characteristics of intensive reading and how to cultivate the intensive reading skills.Since the focus of this papre is how to cultivate the intensive reading skills,we make a systematic exposition from three points: word study,grammar patterns and text.

  12. Fungal cultivation on glass-beads

    DEFF Research Database (Denmark)

    Droce, Aida; Sørensen, Jens Laurids; Giese, Henriette

    Transcription of various bioactive compounds and enzymes are dependent on fungal cultivation method. In this study we cultivate Fusarium graminearum and Fusarium solani on glass-beads with liquid media in petri dishes as an easy and inexpensive cultivation method, that resembles in secondary...

  13. STEM Education.

    Science.gov (United States)

    Xie, Yu; Fang, Michael; Shauman, Kimberlee

    2015-08-01

    Improving science, technology, engineering, and mathematics (STEM) education, especially for traditionally disadvantaged groups, is widely recognized as pivotal to the U.S.'s long-term economic growth and security. In this article, we review and discuss current research on STEM education in the U.S., drawing on recent research in sociology and related fields. The reviewed literature shows that different social factors affect the two major components of STEM education attainment: (1) attainment of education in general, and (2) attainment of STEM education relative to non-STEM education conditional on educational attainment. Cognitive and social psychological characteristics matter for both major components, as do structural influences at the neighborhood, school, and broader cultural levels. However, while commonly used measures of socioeconomic status (SES) predict the attainment of general education, social psychological factors are more important influences on participation and achievement in STEM versus non-STEM education. Domestically, disparities by family SES, race, and gender persist in STEM education. Internationally, American students lag behind those in some countries with less economic resources. Explanations for group disparities within the U.S. and the mediocre international ranking of US student performance require more research, a task that is best accomplished through interdisciplinary approaches.

  14. Stem Cells

    DEFF Research Database (Denmark)

    Sommerlund, Julie

    2004-01-01

    '. This paper is about tech-noscience, and about the proliferation of connections and interdependencies created by it.More specifically, the paper is about stem cells. Biotechnology in general has the power to capture the imagination. Within the field of biotechnology nothing seems more provocative...... and tantalizing than stem cells, in research, in medicine, or as products....

  15. STEM Education

    Science.gov (United States)

    Xie, Yu; Fang, Michael; Shauman, Kimberlee

    2015-01-01

    Improving science, technology, engineering, and mathematics (STEM) education, especially for traditionally disadvantaged groups, is widely recognized as pivotal to the U.S.’s long-term economic growth and security. In this article, we review and discuss current research on STEM education in the U.S., drawing on recent research in sociology and related fields. The reviewed literature shows that different social factors affect the two major components of STEM education attainment: (1) attainment of education in general, and (2) attainment of STEM education relative to non-STEM education conditional on educational attainment. Cognitive and social psychological characteristics matter for both major components, as do structural influences at the neighborhood, school, and broader cultural levels. However, while commonly used measures of socioeconomic status (SES) predict the attainment of general education, social psychological factors are more important influences on participation and achievement in STEM versus non-STEM education. Domestically, disparities by family SES, race, and gender persist in STEM education. Internationally, American students lag behind those in some countries with less economic resources. Explanations for group disparities within the U.S. and the mediocre international ranking of US student performance require more research, a task that is best accomplished through interdisciplinary approaches. PMID:26778893

  16. Putative epidermal stem cell convert into corneal epithelium-like cell under corneal tissue in vitro

    Institute of Scientific and Technical Information of China (English)

    GAO Nan; CUI GuangHui; WANG ZhiChong; HUANG Bing; GE Jian; LU Rong; ZHANG KeFei; FAN ZhiGang; LU Li; PENG Zhan

    2007-01-01

    Rhesus putative epidermal stem cells are being investigated for their potential use in regenerative corneal epithelium-like cells, which may provide a practical source of autologous seed cells for the construction of bioengineered corneas. The goal of this study was to investigate the potential of epidermal stem cells for trans-differentiation into corneal epithelium-like cells. Rhesus putative epidermal stem cells were isolated by type IV collagen attachment method. Flow cytometry analysis, immunohistology and RT-PCR were conducted to identify the expression of specific markers (β1, α6 integrin, K15, K1/K10, K3/K12 and CD71) on the isolated rapid attaching cells. The isolated cells were cocultured with human corneal limbal stroma and corneal epithelial cells. After coculture, the expression of the same specific markers was evaluated in order to identify expression difference caused by the coculture conditions. K3/K12 expression was analyzed in coculture cells on day 2, 4, 6, 8 and 10. Putative epidermal stem cells in conditioned culture media were used as control. Putative epidermal stem cells were predominant in rapid attaching cells by type IV collagen attachment isolation. Before being cocultured, the rhesus putative epidermal stem cells expressed K15, α6 and β1 integrin, but no CD71, K1/K10 and K3/K12. After coculture, these cells expressed K3/K12 (a marker of corneal epithelial cells), K15 and β 1 integrin, but no K1/K10. Cells being not coculture converted into terminally differentiated cells expressing K1/K10. These results indicate that rhesus putative epidermal stem cells can trans-differentiate into corneal epithelium-like cells and, therefore, may have potential therapeutic application as autologous seed cells for the construction of bioengineered corneas.

  17. Putative epidermal stem cell convert into corneal epithelium-like cell under corneal tissue in vitro

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Rhesus putative epidermal stem cells are being investigated for their potential use in regenerative corneal epithelium-like cells, which may provide a practical source of autologous seed cells for the construction of bioengineered corneas. The goal of this study was to investigate the potential of epi-dermal stem cells for trans-differentiation into corneal epithelium-like cells. Rhesus putative epidermal stem cells were isolated by type IV collagen attachment method. Flow cytometry analysis, immuno-histology and RT-PCR were conducted to identify the expression of specific markers (β1, α6 integrin, K15, K1/K10, K3/K12 and CD71) on the isolated rapid attaching cells. The isolated cells were cocultured with human corneal limbal stroma and corneal epithelial cells. After coculture, the expression of the same specific markers was evaluated in order to identify expression difference caused by the coculture conditions. K3/K12 expression was analyzed in coculture cells on day 2, 4, 6, 8 and 10. Putative epi-dermal stem cells in conditioned culture media were used as control. Putative epidermal stem cells were predominant in rapid attaching cells by type IV collagen attachment isolation. Before being co-cultured, the rhesus putative epidermal stem cells expressed K15, α6 and β1 integrin, but no CD71, K1/K10 and K3/K12. After coculture, these cells expressed K3/K12 (a marker of corneal epithelial cells), K15 and β 1 integrin, but no K1/K10. Cells being not coculture converted into terminally differentiated cells expressing K1/K10. These results indicate that rhesus putative epidermal stem cells can trans-differentiate into corneal epithelium-like cells and, therefore, may have potential therapeutic application as autologous seed cells for the construction of bioengineered corneas.

  18. Alternative potassium source for the cultivation of ornamental sunflower

    Directory of Open Access Journals (Sweden)

    Sabrina Thereza dos Santos Torqueti

    2016-06-01

    Full Text Available ABSTRACT Brazil is dependent on importation of fertilizers, especially the potassics. Rocks and minerals that contain nutrients have a potential for use in agriculture as fertilizer, especially those of slow solubilization and that exhibit residual effect. In this context, the objective was to assess the feasibility of glauconite rock as potassium source for the cultivation of ornamental sunflower. The experiment was conducted under controlled conditions arranged in an entirely randomized design, in a 4x4 + 4 factorial scheme, with four replicates and one plant per plot. Four glauconite-based fertilizers were used as a potassium source: fine grained glauconite, fine grained organo-mineral glauconite, coarse grained glauconite and coarse grained organo-mineral glauconite, in four doses, as well as an additional treatment with four doses of KCl, the principal conventional source of the nutrient. The height of the flower stalks, the diameter of the stem and floral capitulum, the number of cultivation days and post-harvest durability were evaluated. The application of KCl yielded the production of flower stems with greater height and larger capitulum diameter in relation to the supply of glauconite. Among the glauconite based fertilizers, the fine grained organo-mineral product provided the best flower charateristics. The postharvest commercial durability of the flower stalks was higher in plants that received the glauconite and fine grained organo-mineral glauconite. The fine grained organo-mineral glauconite surpasses all other alternative sources of potassium in relation to the agronomic characteristics evaluated.

  19. Physiological and agronomical responses of Syrah grapevine under protected cultivation

    Directory of Open Access Journals (Sweden)

    Claudia Rita de Souza

    2015-01-01

    Full Text Available The performance of Syrah grapevine under protected cultivation with different plastic films was evaluated during 2012 and 2013 seasons in South of Minas Gerais State. Agronomical and physiological measurements were done on eight years old grapevines, grafted onto ‘1103 Paulsen’ rootstock cultivated under uncovered conditions, covered with transparent and with diffuse plastic films. Both plastic covers induced the highest shoot growth rate and specific leaf area. The diffuse plastic induced greater differences on leaf area, pruning weight and leaf chlorophyll content as compared to uncovered vines. Grapevines under diffuse plastic also had the lowest rates of photosynthesis, stomatal conductance and transpiration. Leaf starch, glucose and fructose contents were not affected by treatment, but leaf sucrose was reduced by transparent plastic. The leaf and stem water potential were higher under diffuse plastic. In 2013, grapevines under diffuse plastic showed the highest yields mainly due to decreased rot incidence and increased cluster weight. Furthermore, berries under diffuse plastic showed the highest anthocyanins concentration. The use of diffuse plastic induces more agronomical benefits to produce Syrah grape under protected cultivation.

  20. Learn About Stem Cells

    Science.gov (United States)

    ... Patient Handbook Stem Cell Glossary Search Toggle Nav Stem Cell Basics Stem cells are the foundation from which ... original cell’s DNA, cytoplasm and cell membrane. About stem cells Stem cells are the foundation of development in ...

  1. 培养的角膜缘上皮细胞增殖能力的动态研究%A dynamic study on proliferative ability of cultivated limbal epithelial cells

    Institute of Scientific and Technical Information of China (English)

    刘兴华; 朱美玲; 王明丽; 翟自敏

    2002-01-01

    目的探讨组织块培养角膜缘上皮细胞在不同时间以及第2、3代培养的角膜缘上皮细胞早期(6~8 d)的增殖能力.方法应用组织块培养法培养角膜缘上皮细胞,在d8、12、16、20、24用流式细胞仪检测其细胞周期,同时对组织块培养16 d的角膜缘上皮细胞进行传代,用同样方法检测第2、3代细胞出现汇合时(6~8 d)的细胞周期.结果组织块培养角膜缘上皮细胞增殖指数(Proliferative Index,PI)在高水平上呈下降趋势(分别为31.2%、20.1%、17.6%、15.6%、13.4%);2、3代培养细胞早期的增殖指数较高(分别为30.3%、26%).结论组织块培养的角膜缘上皮细胞增殖能力在8~24 d内在高水平上呈下降趋势,第2、3代培养的细胞在培养早期的增殖能力也较高,均适于进行细胞培养移植.

  2. Improving Former Shifted Cultivation Land Using Wetland Cultivation in Kapuas District, Central Kalimantan

    Directory of Open Access Journals (Sweden)

    Wahyudi Wahyudi

    2013-11-01

    Full Text Available Degraded forest area in Kalimantan could be caused by shifted cultivation activity that be conducted by local peoples in the surrounding forest areas. Efforts to improve the former shifted cultivation area (non productive land is developing the settled cultivation by use of irrigation system, better paddy seed, land processing, fertilizing, spraying pesticide, weeding, and better acces to the market. Local peoples, especially in Kalimantan, has been depended their food on the shifted cultivation pattern since the long time ago. This tradition could cause forest damage, forest fire, forest degradation, deforestation, and lose out of children education because they were following shifted cultivation activity although its space is very far from their home. This research was aimed to improve former shifted cultivation lands using wetland cultivation in order to improve land productivity and to support food security in the local community. This research was administratively located in Tanjung Rendan Village, Kapuas Hulu Sub-Ddistrict, Kapuas District, Central Kalimantan Province, Indonesia. Data of rice yield from settled cultivation and shifted cultivation were got from 15 households that was taking by random at 2010 to 2011. Homogeneity test, analysis of variants, and least significant different (LSD test using SPSS 15.0 for Windows. Result of this research showed that paddy yield at settled cultivation was significantly different and better than shifted cultivation at 0.05 level. LSD test also indicated that all paddy yields from settled cultivation were significantly different compare to shifted cultivation at the 0.05 level. The community in Tanjung Rendan Villages preferred settled cultivation than shifted cultivation, especially due to higher paddy production. Profit for settled cultivation was IDR10.95 million ha-1, meanwhile profit for shifted cultivation was just IDR 2.81 million ha-1 only. Settled cultivation pattern could to improve

  3. Effect of culture medium on propagation and phenotype of corneal stroma-derived stem cells.

    Science.gov (United States)

    Sidney, Laura E; Branch, Matthew J; Dua, Harminder S; Hopkinson, Andrew

    2015-12-01

    The limbal area of the corneal stroma has been identified as a source of mesenchymal-like stem cells, which have potential for exploitation as a cell therapy. However, the optimal culture conditions are disputed and few direct media comparisons have been performed. In this report, we evaluated several media types to identify the optimal for inducing an in vitro stem cell phenotype. Primary human corneal stroma-derived stem cells (CSSCs) were extracted from corneoscleral rims. Culture in seven different media types was compared: Dulbecco's modified Eagle's medium (DMEM) with 10% fetal bovine serum (FBS); M199 with 20% FBS; DMEM-F12 with 20% serum replacement, basic fibroblast growth factor and leukemia inhibitory factor (SCM); endothelial growth medium (EGM); semi-solid MethoCult; serum-free keratinocyte medium (K-SFM); and StemPro-34. Effects on proliferation, morphology, protein and messenger RNA expression were evaluated. All media supported proliferation of CSSCs with the exception of K-SFM and StemPro-34. Morphology differed between media: DMEM produced large cells, whereas EGM produced very small cells. Culture in M199 produced a typical mesenchymal stromal cell phenotype with high expression of CD105, CD90 and CD73 but not CD34. Culture in SCM produced a phenotype more reminiscent of a progenitor cell type with expression of CD34, ABCG2, SSEA-4 and PAX6. Culture medium can significantly influence CSSC phenotype. SCM produced a cell phenotype closest to that of a pluripotent stem cell, and we consider it to be the most appropriate for development as a clinical-grade medium for the production of CSSC phenotypes suitable for cell therapy. Copyright © 2015 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  4. Making Friends and Buying Robots: How to Leverage Collaborations and Collections to Support STEM Learning

    Science.gov (United States)

    Kvenild, Cassandra; Shepherd, Craig E.; Smith, Shannon M.; Thielk, Emma

    2017-01-01

    In a climate of increased interest in science, technology, engineering, and math (STEM), school libraries have unique opportunities to grow collections and cultivate partnerships in the sciences. At the federal level and in many states, STEM initiatives encourage hands-on exposure to technologies and open the door for student-led discovery of…

  5. Biodiversity in cultivated Panax notoginseng populations

    Institute of Scientific and Technical Information of China (English)

    Dong WANG; Deborah HONG; Hwee-ling KOH; Ying-jun ZHANG; Chong-ren YANG; Yan HONG

    2008-01-01

    Aim:Panax notoginseng is a cultivated ginseng species highly valued for its various pharmacological activities mostly associated with triterpenoid saponin glycosides. It would be of great interest to understand biodiversity in this gin-seng species after its long history of domestication. Methods: We collected 92 random sampled 3-year-old P notoginseng plants from 4 counties of Wenshan prefecture in Yunnan province, China and documented their morphological fea-tures of plant height, stem color, number of leaves/leaflets and dry weight of tap root. Their genetic diversity was evaluated by fluorescent amplified fragment length polymorphism (fAFLP) analysis. Results: Among the samples collected, variable morphological features were observed. For these 4 populations (Zhulijie, Shangliuhe, Bazai and Jinbuhuan) analyzed by fAFLP, percentage of polymor-phic bands among the total number of 582 discrete bands were 74.05%, 45.36%, 38.83% and 51.89% respectively. Mean genetic heterozygosity were 0.166, 0.093, 0.094 and 0.125. On the other hand, Nei genetic distances among populations were all <0.03. Further analysis of molecular variance (AMOVA) attributed most (93.5%) genetic diversity to within population variation. Principal coordi-nates analysis (PCA) did not group any population distinctively. Conclusion: This domesticated ginseng species still maintains a fair level of biodiversity and this conclusion is consistent with the local practice of non-selective collection of seeds for next season planting. There was no genetic drift in populations. Biodi-versity ofP notoginseng can be exploited to improve this important herb through breeding. Two possible strategies include inbreeding for pure lines and hybrid breeding with genetic divergent parents for hybrid vigor.

  6. Incisões relaxantes limbares durante a cirurgia de catarata: resultados após seguimento de um ano Limbal relaxing incisions during cataract surgery: one-year follow-up

    Directory of Open Access Journals (Sweden)

    João Carlos Arraes

    2006-06-01

    ções pós-operatórias significativas.PURPOSE: To evaluate astigmatism variation between preoperative, 1st and 12th postoperative month of patients who underwent cataract surgery with limbal relaxing incisions (LRI aiming to reduce the preoperative astigmatism. METHODS: Sixteen patients who underwent cataract surgery by the phacoemulsification technique with a 5.5 mm escleral incision, at the Altino Ventura Foudation, between April and July of 2002. The limbal relaxing incisions were performed according to Gills' modified nomogram (1D - 1 LRI of 6 mm; 1-2D - 2 LRI of 6 mm; 2-3D - 2 LRI of 8 mm. They were done in the most curved meridians, determined by preoperative corneal topography. RESULTS: Significant reduction in preoperative astigmatism was observed in the 1st postoperative month in 2 limbal relaxing incisions of the 6 mm group (57% topographic astigmatism and 87% refractional and in 2 limbal relaxing incisions of the 8 mm group (50% topographic astigmatism and 65% refractional, maintaining the reduction with no significant alteration until the 12th postoperative month. The 1 limbal relaxing incision of the 6 mm group did not yield significant astigmatism reduction, but there was no significant alteration until de 12th postoperative month. There were also no complications such as postoperative discomfort, glare, aniseiconia, diplopia, incision infection and corneal thinning or ectasia. CONCLUSION: Two limbal relaxing incisions of 8 and 6 mm aiming to correct preoperative astigmatism of 2 to 3D and 1 to 2D, respectively, were safe and effective with a stable effect in the first postoperative follow-up year. The 1 limbal relaxing incision of 6 mm aiming to reduce 1 diopter of preoperative astigmatism was not effective, but it did not induce any significant postoperative complications.

  7. Cataract surgery with small incision under the limbal conjunctiva%结膜下角膜缘潜行小切口手法白内障手术

    Institute of Scientific and Technical Information of China (English)

    王文战; 陈晓君; 张效房

    2011-01-01

    目的 探讨结膜下角膜缘潜行小切口手法白内障摘出人工晶状体植入术的效果和并发症.方法 于9~12点位间角膜缘的角膜与结膜结合处后方0.5 mm,以45°角斜向切开结膜角膜组织,达1/2角膜厚度,切口宽5.5~6.0 mm.向前在透明角膜内制作隧道,长约2.0 mm.穿刺进入前房.常规连续环形撕囊或截囊,然后借助注水圈匙手法娩核,囊袋内植入人工晶状体.观察1210例1293眼.术前术后测视力及角膜曲率,并做裂隙灯显微镜检查及A/B超检查.随访4~6周.结果 视力:手术前:光感~0.15,手术后:0.05~1.0.角膜曲率:手术前:K1=(43.99±1.83)D,K2=(43.83±2.06)D,手术后2周:K1=(45.08±2.30)D,K2=(44.07±2.86)D(u检验:P>0.5).意外撞伤致切口裂开并虹膜脱出6例6眼,占0.46%.角膜水肿及前房渗出均较轻微,无前房积血、人工晶状体移位或感染等并发症.手术时间一般为5~8 min.结论 结膜下角膜缘潜行小切口手法白内障摘出人工晶状体植入术操作简单,易于掌握,且手术时间短伤口愈合快,并发症少.%Objective To explore the effects and complications of manual cataract extraction and IOL implantation with small incision under the limbal conjunctiva.Methods Cornea conjunctiva tissue Was incised with 45°beveled direction,0.5 mm after the junction of limbus and conjunctiva from 9'clock to 12'clock,with depth of 1/2 cornea and width of 5.5~6.0 mm.The tunnel incision Was produced up to clear cornea with length of 2.0 mm and then punctured into the anterior chamber.After continuous curvilinear capsulotomy or capsulorhexis and manual expulsion the nuclear,IOL Was implanted.1293 eyes of 1210 pa-tients were observed,visual acuity,corneal curvature,slit lamp microscope examination and A/B ultrasonic inspection were recorded before and after surgery.The patients were followed up for 4 to 6 weeks.Results The visual acuity:light pemepfion to 0.15 preoperatively and 0.05 to 1.0 postoperatively

  8. Hybrid origins of cultivated potatoes.

    Science.gov (United States)

    Rodríguez, Flor; Ghislain, Marc; Clausen, Andrea M; Jansky, Shelley H; Spooner, David M

    2010-10-01

    Solanum section Petota is taxonomically difficult, partly because of interspecific hybridization at both the diploid and polyploid levels. The taxonomy of cultivated potatoes is particularly controversial. Using DNA sequence data of the waxy gene, we here infer relationships among the four species of cultivated potatoes accepted in the latest taxonomic treatment (S. ajanhuiri, S. curtilobum, S. juzepczukii and S. tuberosum, the latter divided into the Andigenum and Chilotanum Cultivar Groups). The data support prior ideas of hybrid origins of S. ajanhuiri from the S. tuberosum Andigenum Group (2x = S. stenotomum) × S. megistacrolobum; S. juzepczukii from the S. tuberosum Andigenum Group (2x = S. stenotomum) × S. acaule; and S. curtilobum from the S. tuberosum Andigenum Group (4x = S. tuberosum subsp. andigenum) × S. juzepczukii. For the tetraploid cultivar-groups of S. tuberosum, hybrid origins are suggested entirely within much more closely related species, except for two of three examined accessions of the S. tuberosum Chilotanum Group that appear to have hybridized with the wild species S. maglia. Hybrid origins of the crop/weed species S. sucrense are more difficult to support and S. vernei is not supported as a wild species progenitor of the S. tuberosum Andigenum Group.

  9. NETS FOR PEACH PROTECTED CULTIVATION

    Directory of Open Access Journals (Sweden)

    Evelia Schettini

    2012-06-01

    Full Text Available The aim of this paper was to investigate the radiometric properties of coloured nets used to protect a peach cultivation. The modifications of the solar spectral distribution, mainly in the R and FR wavelength band, influence plant photomorphogenesis by means of the phytochrome and cryptochrome. The phytochrome response is characterized in terms of radiation rate in the red wavelengths (R, 600-700 nm to that in the farred radiation (FR, 700-800 nm, i.e. the R/FR ratio. The effects of the blue radiation (B, 400-500 nm is investigated by the ratio between the blue radiation and the far-red radiation, i.e. the B/FR ratio. A BLUE net, a RED net, a YELLOW net, a PEARL net, a GREY net and a NEUTRAL net were tested in Bari (Italy, latitude 41° 05’ N. Peach trees were located in pots inside the greenhouses and in open field. The growth of the trees cultivated in open field was lower in comparison to the growth of the trees grown under the nets. The RED, PEARL, YELLOW and GREY nets increased the growth of the trees more than the other nets. The nets positively influenced the fruit characteristics, such as fruit weight and flesh firmness.

  10. Phacoemulsification and foldable IOL implantation with limbal tunnel incision%角膜缘隧道切口白内障超声乳化折叠式人工晶体植入术

    Institute of Scientific and Technical Information of China (English)

    吴勇; 黄振平; 曹春林; 薛春燕

    2001-01-01

    目的:评价角膜缘隧道切口的白内障超声乳化折叠式人工晶体植入术的效果。方法:对66例(72眼)老年性、并发性、外伤性白内障采用3.2 mm角膜缘隧道切口,行白内障超声乳化并植入折叠式人工晶体,观察手术前后视力、角膜曲率、角膜地形图的变化。结果:术后1天、1周、1个月的视力达0.5以上者分别占69.4%、80.6%和86.1%,术后1周平均散光为(1.85±0.89)D,比术前增加0.30 D(P0.05,角膜地形图显示已恢复术前状态。结论:角膜缘隧道切口的白内障超声乳化折叠式人工晶体植入术能简化手术步骤,术后视力恢复快,炎症反应轻,具有早期恢复至术前眼屈光状态的优势。%Objectives: To evaluate the efficacy of phacoemulsification and foldable IOL implantation with limbal tunnel incision. Methods: A 3.2mm limbal tunnel incision was made on 72 eyes of 66 patients with senile, complicated and traumatic cataract. Phacoemulsification and foldable IOL implantation was performed. Visual acuity, corneal curvature and corneal topography were measured after the surgery.  Results: One day, one week and one month after the surgery, visual acuity exceeded 0.5 in 69.4%, 80.6%,86.1% of the patients respectively. One week after the surgery, the mean astigmatism was (1.85±0.89)D(P0.05,corneal topography had recovered.  Conclusions: Phacoemulsification and foldable IOL implantation with limbal tunnel incision have comparatively simple, with less postoperative inflammation and faster recovery of visual acuity.

  11. Curbing stem cell tourism in South Africa.

    Science.gov (United States)

    Meissner-Roloff, Madelein; Pepper, Michael S

    2013-12-01

    Stem cells have received much attention globally due in part to the immense therapeutic potential they harbor. Unfortunately, malpractice and exploitation (financial and emotional) of vulnerable patients have also drawn attention to this field as a result of the detrimental consequences experienced by some individuals that have undergone unproven stem cell therapies. South Africa has had limited exposure to stem cells and their applications and, while any exploitation is detrimental to the field of stem cells, South Africa is particularly vulnerable in this regard. The current absence of adequate legislation and the inability to enforce existing legislation, coupled to the sea of misinformation available on the Internet could lead to an increase in illegitimate stem cell practices in South Africa. Circumstances are already precarious because of a lack of understanding of concepts involved in stem cell applications. What is more, credible and easily accessible information is not available to the public. This in turn cultivates fears born out of existing superstitions, cultural beliefs, rituals and practices. Certain cultural or religious concerns could potentially hinder the effective application of stem cell therapies in South Africa and novel ways of addressing these concerns are necessary. Understanding how scientific progress and its implementation will affect each individual and, consequently, the community, will be of cardinal importance to the success of the fields of stem cell therapy and regenerative medicine in South Africa. A failure to understand the ethical, cultural or moral ramifications when new scientific concepts are introduced could hinder the efficacy and speed of bringing discoveries to the patient. Neglecting proper procedure for establishing the field would lead to long delays in gaining public support in South Africa. Understanding the dangers of stem cell tourism - where vulnerable patients are subjected to unproven stem cell therapies that

  12. Curbing stem cell tourism in South Africa

    Directory of Open Access Journals (Sweden)

    Madelein Meissner-Roloff

    2013-12-01

    Full Text Available Stem cells have received much attention globally due in part to the immense therapeutic potential they harbor. Unfortunately, malpractice and exploitation (financial and emotional of vulnerable patients have also drawn attention to this field as a result of the detrimental consequences experienced by some individuals that have undergone unproven stem cell therapies. South Africa has had limited exposure to stem cells and their applications and, while any exploitation is detrimental to the field of stem cells, South Africa is particularly vulnerable in this regard. The current absence of adequate legislation and the inability to enforce existing legislation, coupled to the sea of misinformation available on the Internet could lead to an increase in illegitimate stem cell practices in South Africa. Circumstances are already precarious because of a lack of understanding of concepts involved in stem cell applications. What is more, credible and easily accessible information is not available to the public. This in turn cultivates fears born out of existing superstitions, cultural beliefs, rituals and practices. Certain cultural or religious concerns could potentially hinder the effective application of stem cell therapies in South Africa and novel ways of addressing these concerns are necessary. Understanding how scientific progress and its implementation will affect each individual and, consequently, the community, will be of cardinal importance to the success of the fields of stem cell therapy and regenerative medicine in South Africa. A failure to understand the ethical, cultural or moral ramifications when new scientific concepts are introduced could hinder the efficacy and speed of bringing discoveries to the patient. Neglecting proper procedure for establishing the field would lead to long delays in gaining public support in South Africa. Understanding the dangers of stem cell tourism – where vulnerable patients are subjected to unproven stem

  13. Community Characteristics of Early Recovery Vegetation on Abandoned Lands of Shifting Cultivation in Bawangling of Hainan Island, South China

    Institute of Scientific and Technical Information of China (English)

    Yi DING; Run-Guo ZANG

    2005-01-01

    Shifting cultivation is a major form of agricultural practice in most parts of tropical regions worldwide. In places where the bush fallow period is excessively shortened or the period of cultivation is extended for too long, the rate of vegetation recovery and biodiversity on abandoned lands of shifting cultivation would decline. The recovery of the secondary plant communities could even be inhibited for a prolonged period because of grass occupancy. Because of the vital significance of the early recovery communities to secondary succession, we studied the community characteristics of early recovery vegetation on abandoned lands of shifting cultivation in Bawangling of Hainan Island. Measurements were made of the community composition and structure of early recovery vegetation. The sprouting abilities of different functional groups and different species in the same functional group, and the effect of the grass functional group on the composition and quantitative characteristics of tree and shrub functional groups were analyzed. Results indicated that only a few families, genera, or species apparently dominated in the early recovery vegetation on the abandoned lands of shifting cultivation and that deciduous species occurred with a rather high percentage in this early recovery community compared with the natural secondary or old growth forests. Smallsized individuals dominated the woody community. The abundance and basal area of sprouting stems for species in the tree functional group were greater than those of seeder stems, whereas the abundance and basal area of resprouters and seeders for species in the shrub functional group did not differ. The total abundance of stems for the community, stem abundances for species in tree or shrub functional groups, and for seeder or resprouter stems were all negatively correlated with coverage of the grass functional group. The mean sprouting ability in the tree functional group was greater than in the shrub functional group

  14. Comparative study on influence of fetal bovine serum and serum of adult rat on cultivation of newborn rat neural cells

    Directory of Open Access Journals (Sweden)

    Sukach A. N.

    2014-09-01

    Full Text Available Aim. To study the influence of fetal bovine serum and serum of adult rats on behavior of newborn rat isolated neural cells during their cultivation in vitro. Methods. The isolation of neural cells from neonatal rat brain. The determination of the dynamics of cellular monolayer formation. Immunocytochemical staining of cells for β-tubulin III, nestin and vimentin. Results. It has been determined that the addition of serum of adult rats to the cultivation medium creates more favorable conditions for survival, attachment and spread of differentiated, and proliferation of the stem/progenitor neural cells of newborn rats during cultivation in vitro compared with the fetal bovine serum. Conclusions. Using the serum of adult rats is preferable for the cultivation of isolated neural cells of newborn rats compared with the fetal bovine serum.

  15. Cultivation, identification and directional differentiation potency of human anmiotic fluid-derived multipotential stem cells%羊水来源多潜能干细胞的培养鉴定及其定向分化能力研究

    Institute of Scientific and Technical Information of China (English)

    顾潇; 张建芳; 郭倩; 吴珊珊; 陈必良

    2011-01-01

    目的 建立人羊水来源多潜能干细胞的体外培养体系,探讨其生物学特性和定向分化能力.方法 取人孕中期羊水标本进行原代培养,采用贴壁法分离获得干细胞.以流式细胞仪检测细胞表面抗原的表达,并使用特定培养基诱导羊水多潜能干细胞向成骨细胞、脂肪细胞、神经细胞分化.结果 体外培养的羊水干细胞呈纺锤形,增长迅速,细胞表达Oct-4、SSEA-4、CD29、CD44、CD105、CD117,但不表达造血干细胞表面标志CD45、CD133.羊水干细胞在体外诱导可以分化出成骨细胞、脂肪细胞和神经细胞.结论 分离获得的干细胞体外增殖能力强,可表达多潜能干细胞和胚胎干细胞的标志基因,符合多潜能干细胞的特点.在适宜的培养条件下,羊水多潜能干细胞具有向成骨细胞、脂肪细胞、神经细胞分化的能力.%Objective To establish a procedure for culturing amniotic fluid-derived multipotential stem cells in vitro, and study their biological characteristics and differentiation potency. Methods Amniotic fluid-derived stem cells were isolated from second-trimester arnniotuc fluid by adherence. The phenotypes of amniotic fluid-derived stem cells were detected by flow cytometry. The amniotic fluidderived stem cells were induced to differentiate into osteoblasts, adipocytes and neurocytes by specific culture medium. Results The stem cells were successfully isolated from 8 of 10 second-trimester amniotic fluid samples. The amniotic fluid-derived stem cells were spindle in shape and proliferated rapidly. Primary cultured cells grew slowly, and then the growth became rapid following passaging. The chromosome karyotype of the 20th passage was normal, remaining to be 46, XX or 46, XY. These cells shared immunophenotype of both multipotential stem cell and embryonic stem cell markers, as they were positive for Oct-4, SSEA-4, CD29, CD44, CD105 and CD117 expressions, and negative for CD45 and CD133 expressions

  16. Cultivation and Differentiation of Encapsulated hMSC-TERT in a Disposable Small-Scale Syringe-Like Fixed Bed Reactor

    DEFF Research Database (Denmark)

    Weber, Christian; Pohl, Sebastian; Pörtner, Ralf

    2007-01-01

    The use of commercially available plastic syringes is introduced as disposable small-scale fixed bed bioreactors for the cultivation of implantable therapeutic cell systems on the basis of an alginate-encapsulated human mesenchymal stem cell line. The system introduced is fitted with a noninvasiv...... the fixed bed reactor an interesting option for GMP processes. The cultivation of the encapsulated cells in the fixed bed bioreactor system offered vitalities and adipogenic differentiation similar to well-mixed suspension cultures....

  17. Modern, sustainable, protected greenhouse cultivation in Algeria

    NARCIS (Netherlands)

    Os, van E.A.; Speetjens, S.L.; Ruijs, M.N.A.; Bruins, M.A.; Sapounas, A.

    2012-01-01

    The goal of the project was to analyse the structure and technology level of protected cultivation in Algeria, which were followed by recommendations for improvements (technical, cultivation and economic aspects) of existing and newly built greenhouses. Further, in discussion with Dutch and Algerian

  18. My Understanding on Cultivation of Autonomous Learning

    Institute of Scientific and Technical Information of China (English)

    张金玉

    2007-01-01

    Autonomous learning has been popular in western education system for some time, this article aims to analyze the connotation and the necessity of cultivating learner autonomy, and then offer some strategies about the cultivation of learner autonomy from a chinese perspective.

  19. Modern, sustainable, protected greenhouse cultivation in Algeria

    NARCIS (Netherlands)

    Os, van E.A.; Speetjens, S.L.; Ruijs, M.N.A.; Bruins, M.A.; Sapounas, A.

    2012-01-01

    The goal of the project was to analyse the structure and technology level of protected cultivation in Algeria, which were followed by recommendations for improvements (technical, cultivation and economic aspects) of existing and newly built greenhouses. Further, in discussion with Dutch and Algerian

  20. Why STEM?

    Science.gov (United States)

    Mitts, Charles R.

    2016-01-01

    The International Technology and Engineering Educators Association (ITEEA) defines STEM as a new transdisciplinary subject in schools that integrates the disciplines of science, technology, engineering, and mathematics into a single course of study. There are three major problems with this definition: There is no consensus in support of the ITEEA…

  1. Stem cells.

    Science.gov (United States)

    Redi, Carlo Alberto; Monti, Manuela; Merico, Valeria; Neri, Tui; Zanoni, Mario; Zuccotti, Maurizio; Garagna, Silvia

    2007-01-01

    The application of stem cells to regenerative medicine is one of the actual hot topics in biomedicine. This research could help the cure of a number of diseases that are affecting a large share of the population. Some good results in cell replacement have already been obtained (infarcted heart, diabetes, Parkinson disease), apart from those of more traditional applications like severe burns and blood tumors. We are now facing crucial questions in stem cell biology. One of the key questions is how a cell begins to proliferate or differentiate. Genome reprogramming, both following nuclear transfer and cytoplast action, will likely highlight some of the molecular mechanisms of cell differentiation and dedifferentiation. In turn, these clues should be useful to the production of populations of reprogrammed cells that could develop into tissues or, in the future, into proper organs. We will overview what stem cells are, what roles they play in normal developmental processes and how stem cells could have the potential to treat diseases.

  2. Surface modification of closed plastic bags for adherent cell cultivation

    Science.gov (United States)

    Lachmann, K.; Dohse, A.; Thomas, M.; Pohl, S.; Meyring, W.; Dittmar, K. E. J.; Lindenmeier, W.; Klages, C.-P.

    2011-07-01

    In modern medicine human mesenchymal stem cells are becoming increasingly important. However, a successful cultivation of this type of cells is only possible under very specific conditions. Of great importance, for instance, are the absence of contaminants such as foreign microbiological organisms, i.e., sterility, and the chemical functionalization of the ground on which the cells are grown. As cultivation of these cells makes high demands, a new procedure for cell cultivation has been developed in which closed plastic bags are used. For adherent cell growth chemical functional groups have to be introduced on the inner surface of the plastic bag. This can be achieved by a new, atmospheric-pressure plasma-based method presented in this paper. The method which was developed jointly by the Fraunhofer IST and the Helmholtz HZI can be implemented in automated equipment as is also shown in this contribution. Plasma process gases used include helium or helium-based gas mixtures (He + N2 + H2) and vapors of suitable film-forming agents or precursors such as APTMS, DACH, and TMOS in helium. The effect of plasma treatment is investigated by FTIR-ATR spectroscopy as well as surface tension determination based on contact angle measurements and XPS. Plasma treatment in nominally pure helium increases the surface tension of the polymer foil due to the presence of oxygen traces in the gas and oxygen diffusing through the gas-permeable foil, respectively, reacting with surface radical centers formed during contact with the discharge. Primary amino groups are obtained on the inner surface by treatment in mixtures with nitrogen and hydrogen albeit their amount is comparably small due to diffusion of oxygen through the gas-permeable bag, interfering with the plasma-amination process. Surface modifications introducing amino groups on the inner surface turned out to be most efficient in the promotion of cell growth.

  3. Mesenchymal stem cell ingrowth and differentiation on coralline hydroxyapatite scaffolds

    DEFF Research Database (Denmark)

    Mygind, Tina; Stiehler, Maik; Baatrup, Anette

    2007-01-01

    Culture of osteogenic cells on a porous scaffold could offer a new solution to bone grafting using autologous human mesenchymal stem cells (hMSC) from the patient. We compared coralline hydroxyapatite scaffolds with pore sizes of 200 and 500 microm for expansion and differentiation of hMSCs. We......MSC in a particular direction. We found that dynamic spinner flask cultivation of hMSC/scaffold constructs resulted in increased proliferation, differentiation and distribution of cells in scaffolds. Therefore, spinner flask cultivation is an easy-to-use inexpensive system for cultivating hMSCs on small...... cultivated the hMSC statically or in spinner flasks for 1, 7, 14 and 21 days and found that the 200-microm pore scaffolds exhibited a faster rate of osteogenic differentiation than did the 500-microm pore scaffolds as shown by an alkaline phosphatase activity assay and real-time reverse transcriptase...

  4. Advancing gut microbiome research using cultivation

    DEFF Research Database (Denmark)

    Sommer, Morten OA

    2015-01-01

    Culture-independent approaches have driven the field of microbiome research and illuminated intricate relationships between the gut microbiota and human health. However, definitively associating phenotypes to specific strains or elucidating physiological interactions is challenging for metagenomic...... approaches. Recently a number of new approaches to gut microbiota cultivation have emerged through the integration of high-throughput phylogenetic mapping and new simplified cultivation methods. These methodologies are described along with their potential use within microbiome research. Deployment of novel...... cultivation approaches should enable improved studies of xenobiotic tolerance and modification phenotypes and allow a drastic expansion of the gut microbiota reference genome catalogues. Furthermore, the new cultivation methods should facilitate systematic studies of the causal relationship between...

  5. How to Cultivate the Student's Cultural Awareness

    Institute of Scientific and Technical Information of China (English)

    tian xiu ying

    2008-01-01

    Language and culture are inseparable and cultural awareness must be integrated with language teaching. How to cultivate the learners' cultural awareness is an important issue that we have to carry out in teaching practice in China.

  6. Cultivating Citizen Scientists in the Undergraduate Science Classroom

    Science.gov (United States)

    Egger, A. E.

    2007-12-01

    Several studies indicate a strong correlation between the number of college science courses and science literacy. It is not surprising, then, that the majority of participants in citizen science projects are college graduates who enrolled in at least two science courses. If one goal of citizen science projects is to increase civic science literacy, research suggests that most are preaching to the choir. Attracting a wider audience to citizen science is, therefore, a key challenge. One way to address this challenge is to attract students to enroll and succeed in science courses in college, even if they do not pursue a major in the science, technology, engineering, and mathematics (STEM) disciplines. In fact, only 20% of students receive a degree in STEM, yet virtually all undergraduates are required to take at least one science course. Introductory science courses are therefore critical to cultivating citizen scientists, as they include a large proportion of non- STEM majors. Indeed, a major thrust of recent undergraduate STEM educational reform has been the promotion of 'science for all'. The science for all concept goes beyond recruiting students into the STEM disciplines to promoting a level of scientific literacy necessary to make informed decisions. A clear implication of this inclusive attitude is the need to redesign introductory science courses to make them accessible and explicitly related to scientific literacy. This does not mean dumbing down courses; on the contrary, it means engaging students in real scientific investigations and incorporating explicit teaching about the process of science, thus fostering a lifelong appreciation for (and, hopefully, participation in) science. Unfortunately, many students enter college with minimal understanding of the process of science. And when they arrive in their introductory classes, science is presented to them as a system of facts to be memorized - comparable to memorizing a poem in a foreign language without

  7. Prospect of Tea Cultivation & Processing in Pakistan

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    HistoryIn 1958, a farmer brought some tea seeds and plants from Bangladesh (then east Pakistan), and successfully cultivated them in district Mansehra. At that time, Pakistan was self-sufficient in tea that was produced in East Pakistan. After the separation (in 1971) of East Pakistan, Pakistan diverted attention to initial work on tea production. The Pakistan Agricultural Research Council (PARC) took over the charge of tea cultivation in 1976-77 and launched a project in 1980.

  8. Cultivating the social-emotional imagination in gifted education: insights from educational neuroscience.

    Science.gov (United States)

    Gotlieb, Rebecca; Hyde, Elizabeth; Immordino-Yang, Mary Helen; Kaufman, Scott Barry

    2016-08-01

    Evidence from education, psychology, and neuroscience suggests that investing in the development of the social-emotional imagination is essential to cultivating giftedness in adolescents. Nurturing these capacities may be especially effective for promoting giftedness in students who are likely to lose interest and ambition over time. Giftedness is frequently equated with high general intelligence as measured by IQ tests, but this narrow conceptualization does not adequately capture students' abilities to utilize their talents strategically to fully realize their future possible selves. The brain's default mode network is thought to play an important role in supporting imaginative thinking about the self and others across time. Because this network's functioning is temporarily attenuated when individuals engage in task- and action-oriented focus (mindsets thought to engage the brain's executive attention network), we suggest that consistently focusing students on tasks requiring immediate action could undermine long-term cultivation of giftedness. We argue that giftedness-especially in science, technology, engineering, and mathematics (STEM)-can be cultivated by encouraging adolescents' intellectual curiosity and supporting their ability to connect schoolwork to a larger purpose. Improving STEM and gifted education may depend upon a shift from knowledge transmission and regimented evaluation to creative exploration, intentional reflectiveness, and mindful switching between task focus and imagining.

  9. Feasibility Study on Soilless Cultivation of Organic Ginseng

    Institute of Scientific and Technical Information of China (English)

    Yuji JIN; Hongyan ZHAO; Xiangguo LI; Renzhe PIAO

    2015-01-01

    Based on the present situation and problems concerning ginseng cultivation as well as soilless cultivation features,we analyze the growth indicators and input-output ratio of different ginseng cultivation patterns,and conform that the soilless cultivation technology for organic ginseng is feasible. And this technology provides theoretical basis and technological feasibility for the sustainable development of ginseng industry.

  10. Ocular Surface Reconstruction: Recent Innovations

    Directory of Open Access Journals (Sweden)

    Madhavan HN

    2009-01-01

    protocol of LSCD patients. Autologous limbal transplantation Despite its success, its utility is limited. the requirement for a sizable limbal donation; up to 30-40% must be harvested from the contralateral donor eye and its harvest may theoretically harm the structural integrity, cause subclinical LSCD or cryptogenic changes in the donor eye. Ex vivo expansion and cultivation techniques for autologous limbal stem cells are being actively investigated. , the use of human AM for ocular surface regeneration (OSR and as a growth support substrate for ex vivo expansion of autologous corneal equivalent epithelial cells and their successful OSR in animal cornea model, as well as human, was reported. The conventional cultivation methods for corneal epithelial tissues for clinical transplantation applications involve utilization of xenobiotic materials such as fetal bovine serum (FBS and murine-derived feeder cells. FBS-free culture systems have been developed to reduce the risk of zoonotic infection, but these have the disadvantage of reduced efficacy for cell propagation. it must be emphasized that AMT is not a substitution for LSCT and AMT should not be performed when true LSCD exists because AM only provides a supportive matrix for the limbal stem cells to migrate, proliferate and restore the corneal surface. There are several disadvantages of AMT and LSCT technique. This delicate procedure requires technical skill for the preparation of AM with attached corneal epithelial cells and surgical dexterity to manipulate the AM onto the ocular surface.A rabbit model for transplantation of cultivated corneal limbal stem cells onto corneal stem cell deficient animals was developed & its results are very encouraging for similar studies in human corneal surface reconstruction. Our investigations indicated that Ex vivo cultivation of human corneal limbal stem cells (HCLSC occurred with ease in the thermoresponsive biodegradable gel - “Mebiol Gel”. The growth rate within Mebiol Gel

  11. Differential Expression of Stem Cell Markers in Ocular Surface Squamous Neoplasia

    Science.gov (United States)

    Mishra, Dilip Kumar; Veena, Uppala; Kaliki, Swathi; Kethiri, Abhinav Reddy; Sangwan, Virender S.; Ali, Mohammed Hasnat; Naik, Milind N.; Singh, Vivek

    2016-01-01

    Ocular Surface Squamous Neoplasm (OSSN) is the neoplasia arising from the conjunctiva, cornea and limbus. OSSN ranges from mild, moderate, severe dysplasia, carcinoma in situ (CIS) to squamous cell carcinoma (SCC). Recent findings on cancer stem cells theory indicate that population of stem-like cell as in neoplasia determines its heterogeneity and complexity leading to varying tumor development of metastatic behavior and recurrence. Cancer stem cell markers are not much explored in the cases of OSSN. In the present study, we aim to evaluate the expression of stem cells using stem cell markers mainly p63, ABCG2, c-KIT (CD117) and CD44 in OSSN tissue, which could have prognostic significance. The present study tries for the first time to explore expression of these stem markers in the cases of OSSN. These cases are subdivided into two groups. One group comprises of carcinoma in situ (n = 6) and the second group comprises of invasive carcinoma (n = 6). The mean age at presentation was 52 years; with 53 years for CIS group and 52 years for SCC group. From each group section from the paraffin block were taken for the IHC staining of p63, c-Kit, ABCG2 and CD44. Our experiments show high expression of P63 and CD44 in the cases of CIN and SCC. Both CIS and SCC displayed positive staining with p63, with more than 80% cells staining positive. However minimal expression of c-kit in both CIN and SCC. But surprisingly we got high expression of ABCG2 in cases of carcinoma in situ as compared to that of invasive squamous cell carcinoma. More than 50% of cells showed CD44 positivity in both CIS and SCC groups. Our results show for the first time that these four stem cells especially the limbal epithelium stem cells play a vital role in the genesis of OSSN but we need to explore more cases before establishing its clinical and biological significance. PMID:27584160

  12. A study on Heavy Metal Contents in Cultivated Wild Ginseng from Korea and China

    Directory of Open Access Journals (Sweden)

    Jong-Yoon,Kim

    2007-02-01

    Full Text Available Objectives : Heavy metal contents in cultivated wild ginseng from Korea and China were evaluated for the safety purpose. Methods : Arsenic(As, cadmium(Cd, lead(Pb, mercury(Hg, copper(Cu, chromium(Cr, and selenium(Se from the root, stem, and leaves of the Korean cultivated wild ginseng and the root of the Chinese cultivated wild ginseng were analyzed for the existence of heavy metal contents. Results : Most of heavy metals weren't detected in all the samples. Copper and lead were found in very minute volume and didn't reach the toxic concentration level of 10mg/kg. Samples used in the test were grown in non-contaminated areas, free from heavy metal contamination. Conclusions : Based on above results, cultivated wild ginseng from Korea and China are relatively safe from the heavy metal exposure. But for more rigorous quality control, an epidemiological survey using the samples from more diverse areas should be conducted.

  13. Limbal autograft transplantation in a dog with alkali-induced ulceration Transplante de limbo autógeno em cão com úlcera por álcali

    Directory of Open Access Journals (Sweden)

    Fábio Luiz da Cunha Brito

    2010-08-01

    Full Text Available A case of a 3-month-old female mongrel dog with a history of apathy and previous contact with an alkaline (sodium hydroxide is reported. The dog was reluctant to open the right eye. Ophthalmic examination revealed blepharospasm, photophobia, epiphora, discrete chemosis, conjunctival hyperemia, and diffuse corneal edema involving the limbus. The fluorescein test was positive and the result of the Schirmer tear test was 32mm min-1. On the basis of these findings the diagnosis was alkali-induced ulceration and limbal autograft transplantation was performed. Corneal vascularization was observed by the third postoperative day, with intensification in vessel number and caliber on subsequent days and small areas of corneal transparency. The present results show that limbal autograft transplantation is a feasible procedure for the therapeutic management of alkali-induced corneal ulcers.Descreve-se um caso de um animal da espécie canina, fêmea, sem raça definida, de três meses de idade, com histórico de apatia, contato prévio com produto alcalino (hidróxido de sódio e relutância em abrir o olho direito. Ao exame oftálmico, foram observados blefarospasmo, fotofobia, epífora, quemose discreta, hiperemia conjuntival, e edema corneal difuso com comprometimento do limbo. Foram realizados o teste da fluoresceína positivo e o Teste Lacrimal de Schirmer 32mm min-1. Com base nos achados, firmou-se o diagnóstico de úlcera por álcali e realizou-se transplante autógeno do limbo. No pós-operatório, observou-se vascularização corneal a partir do terceiro dia e sua intensificação, em número e calibre, nos dias subseqüentes. Também foram observadas mínimas áreas de transparência corneal. Os resultados obtidos permitem admitir que o transplante autógeno de limbo é procedimento factível para o manejo da terapia de úlceras de córnea por álcali.

  14. Differentiation of embryonic stem cells into corneal epithelium

    Institute of Scientific and Technical Information of China (English)

    WANG Zhichong; LIU Jingbo; GE Jian; HUANG Bing; GAO Qianying; LIU Bingqian; WANG Linghua; YU Ling; FAN Zhigang; LU Xiaoming

    2005-01-01

    Our project was to determine whether embryonic stem (ES) cells could be induced to differentiate into corneal epithelia by superficial corneoscleral limbal stroma. To achieve this goal, ES-GFP cell line D3 was pre-induced by retinoic acid (RA). The pre-induced cells were seeded on deepithelialized superficial corneoscleral slices (SCSS) to form a monolayer, and divided into three groups. Group 1 was cultured and passaged in vitro for direct detection. Group 2 was exposed to air-liquid interfaces for 10 days and implanted into the subcutaneous layer of nude mice for 2 weeks for further induction in vivo. Group 3 was cultured in vitro without any inducing factors for control. There were no teratomas found in nude mice which were implanted with differentiated ES cells after two weeks. The differentiated cells showed an appearance of epithelia both in vitro and in vivo. Expression of CK3, P63 and PCNA was detected by immunohistochemical staining in the differentiated cells in group 1 and 2. Microvillis and zonula occludens were observed on the surface of the differentiated cells under an electron microscope. In the control group, ES cells differentiated freely without any inducing factors. Most cells were shed and formed a neuronal dendrite-like structure, and a minority of cells appeared polymorphic. These results demonstrate that ES cells can differentiate into corneal epithelia on the surface of SCSS under the controlled condition. Differentiated ES cells could be used as epithelial seeding cells for the reconstruction of ocular surface and corneal tissue engineering in the future.

  15. Anticipatory Life Cycle Analysis of In Vitro Biomass Cultivation for Cultured Meat Production in the United States.

    Science.gov (United States)

    Mattick, Carolyn S; Landis, Amy E; Allenby, Braden R; Genovese, Nicholas J

    2015-10-06

    Cultured, or in vitro, meat consists of edible biomass grown from animal stem cells in a factory, or carnery. In the coming decades, in vitro biomass cultivation could enable the production of meat without the need to raise livestock. Using an anticipatory life cycle analysis framework, the study described herein examines the environmental implications of this emerging technology and compares the results with published impacts of beef, pork, poultry, and another speculative analysis of cultured biomass. While uncertainty ranges are large, the findings suggest that in vitro biomass cultivation could require smaller quantities of agricultural inputs and land than livestock; however, those benefits could come at the expense of more intensive energy use as biological functions such as digestion and nutrient circulation are replaced by industrial equivalents. From this perspective, large-scale cultivation of in vitro meat and other bioengineered products could represent a new phase of industrialization with inherently complex and challenging trade-offs.

  16. Black truffle cultivation: a global reality

    Directory of Open Access Journals (Sweden)

    Santiago Reyna

    2014-08-01

    Full Text Available Aim of study: In recent decades the cultivation of the black truffle Tuber melanosporum has expanded across all the Mediterranean-climate regions, but also to other regions outside the European standard for the species. We aim to describe the current extent of T. melanosporum cultivation.Area of study: Tuber melanosporum plantations in Europe, the Mediterranean basin, Australia, New Zealand, China, America and South Africa.Material and Methods: The socioeconomic impact of T. melanosporum cultivation, the way in which the current situation has been achieved and the knowledge needed for its progress are reviewed.Research highlights: T. melanosporum has been successfully cultivated in several countries outside its natural area, but many practices are still empirical and thus yields cannot be guaranteed. The recent advances in molecular techniques and genome science are helping to overcome some of the difficulties traditionally constraining truffle research. The role of truffles as a transitional element between agricultural and forestry activities makes its cultivation a paradigm of sustainable rural development.Keywords: Tuber melanosporum; Europe; Australia; New Zealand; Chile; USA.

  17. Prospects for Sorghum cultivation in Poland

    Directory of Open Access Journals (Sweden)

    Roman Prażak

    2016-06-01

    Full Text Available The article presents the origin and cultivation history of sorghum (Sorghum spp., its biology, requirements, cultivation techniques, and utilization. Sorghum is a cereal of the Poaceae. It is one of the most important crop plants grown in warmer parts of the world. Sorghum comes from Africa and therefore has very high heat requirements. In comparison with other crop plants, it is characterized by more efficient nutrient and water utilization. Sorghum grain is used to produce porridge, flour, syrup, sugar, ethanol, vegetable oil, starch, wax, paints, and animal fodder (the grain and entire plant. Sorghum straw is used to produce fibres, paper, and building materials. Sorghum has high energy value and can be an excellent source of renewable energy. It is easy to cultivate, with low soil and nutrient requirements. Due to its content of allelopathic compounds, it inhibits weed growth and has a phytosanitary effect. It is also resistant to disease and pests. It is a short-day plant, and in Polish climate conditions, it does not form sufficiently mature seeds, but produces a very high yield of green matter that can be used for fodder. Cultivation of sorghum during periodic water shortages may be an alternative solution for obtaining fodder when maize cultivation is unreliable.

  18. Alternative substrates for higher mushrooms mycelia cultivation

    Directory of Open Access Journals (Sweden)

    TETIANA KRUPODOROVA

    2015-12-01

    Full Text Available Cultivation of 29 species of higher mushroom mycelia on alternative substrates – wastes of Ukrainian oil-fat industry, has been investigated. The amount of mushroom mycelia obtaining on 12 investigated substrates varied significantly, from 1.0 g/L to 22.9 g/L on the 14th day of cultivation. The superficial cultivation adopted in this study allows for easy to choose appropriate medium (substrate for mycelia production. Alternative substrates (compared to glucose-peptone-yeast medium were selected for all studied species, from soybean cake – most suitable for the mycelial growth of 24 species, to walnut cake − suitable only for 2 species. The utilization of substrates has been evaluated by biological efficiency. The best index of biological efficiency varied from 19.0% to 41.6% depending on the mushroom species. It was established high biological efficiency of mycelia cultivation on substrates: wheat seed cake – Pleurotus djamor, Lyophyllum shimeji, Crinipellis schevczenkovi, Phellinus igniarius, Spongipellis litschaueri; oat seed cake – Ganoderma applanatum and G. lucidum; soybean cake – Hohenbuehelia myxotricha, Trametes versicolor, Morchella esculenta, Cordyceps sinensis, C. militaris, and Agrocybe aegerita; rape seed cake – Auriporia aurea; camelina seed cake – Fomes fomentarius. The cultivation of these species are perspective as a biotechnological process of agricultural wastes converted into mycelia, which could be used in different forms of products with therapeutic action: powder or tablets nutraceuticals or ingredients for functional foods.

  19. Green tide: indoor marihuana cultivation and its impact on Ontario

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    This paper discusses the apparent proliferation of marihuana grow-ops in Ontario over the last five years. Estimated revenues from indoor marihuana were detailed, as well as estimates of quantities of marihuana produced, forecasted trends and annual and weekly historical trends. The potential economic impact of this criminal activity was examined, with particular reference to increased police activities. The potential for fire and other human health risks included: exposure to mould associated with hydroponic cultivation and growth chemicals and higher concentrations of carbon dioxide and carbon monoxide. The socio-economic impact of grow ops were examined, with detailed estimates of law enforcement costs, insurance costs and costs to the justice system. Societal costs, such as environmental hazards, violence associated with organized crime, and the perceived threat to Ontario's children and communities were also outlined. Costs stemming from hydro theft were cited, including hydro repair and administration. Details of the bypass systems installed for hydro theft were also provided. It was concluded that it was unlikely that grow ops will be entirely eradicated. Measures that may limit the scope of grow ops included: developing avenues to increase effectiveness and efficiency of law enforcement approaches to grow ops, enhancing lines of communication and sharing of intelligence between police and other key stakeholders such as insurance companies, real estate agencies and banks and educating persons in the justice system on the issue of grow ops so that sentencing more accurately reflects the crime. It was recommended that lenient sentencing for marihuana possession and cultivation be re-examined. 70 refs., 12 tabs, 38 figs.

  20. Phenylhydrazines in the cultivated mushroom (Agaricus bisporus)

    DEFF Research Database (Denmark)

    Andersson, H. C.; Gry, Jørn

    2004-01-01

    In 1991, the Nordic Working Group on Food Toxicology and Risk Evaluation (NNT) reviewed the available data on phenylhydrazines naturally occurring in the cultivated mushroom. It was concluded that the mushroom may contain about 500 mg of the hydrazine derivatives per kg fresh weight. The hydrazine...... derivatives as well as extracts of the cultivated mushroom were mutagenic to a variable degree in most of the reported short-term tests. The raw mushroom and several of the hydrazines induced tumours when administered to Swiss mice as reported by American scientists. However, reservations were expressed...... as to the design of the studies. Based on this review, and due to the concern expressed, a Nordic project (coordinated by Jørn Gry, Danish Veterinary and Food Administration) was initiated dealing with toxicological and chemical studies on the cultivated mushroom and its phenylhydrazine derivatives in order...

  1. Application of photobioreactors to cultivation of microalgae

    Institute of Scientific and Technical Information of China (English)

    陈雷; 王光玉

    2003-01-01

    An overview of photobioreactors now in use for production of microalgae world wide is presented, andthe application of photobioreactors to the cultivation of microalgae is discussed in detail. It is pointed out thathigh cell density and industrial production of microalgae can be achieved using many kinds of closed photobiore-actors including fermentor, tubular and flat plate photobioreactors, and the cultivation of Spirulina, Chlorella,Dunaliella tertiolecta and Porphyridium cruentrim by photobioreactors can achieve higher and steadier produc-tivity than the cultivation of microalgae by an open air system. More and more researches indicate that tubularand flat plate photobioreactors are the development trend for photobioreactors with bubbles and air lift stirrers,and high bright light-emitting diodes are the most economic light source with great potential for future develop-ment of photobioreactors. Photobioreactors can also be used for the production of high-value metabolite ( EPA orDHA) using some microalgae species for energy development and environment protection.

  2. Zeolites as possible biofortifiers in Maitake cultivation

    Directory of Open Access Journals (Sweden)

    Vunduk Jovana

    2014-01-01

    Full Text Available The levels of Ni, Cu and Mg in Grifola frondosa (also known as Maitake mushroom fruit body produced on zeolite Minazel Plus (MG-supplemented substrate were measured with inductively coupled plasma optical emission spectrometry (ICP-OES. Two different concentrations of MG were added to the substrate for mushroom cultivation. Levels of selected metals were measured in cultivated dry carpophores. The content of Ni increased in fruit bodies produced on supplemented substrate, while in case of Cu, a pronounced decrease was observed. When two different concentrations of MG were implemented, the Mg level showed both positive and negative trend, depending on the applied concentration of zeolite. MG in a concentration of 1% showed the strongest influence on the observed elements in the cultivated fruiting body of Maitake mushroom. [Projekat Ministarstva nauke Republike Srbije, br. 46010

  3. Cultivation of EFL Learners’Intercultural Competence

    Institute of Scientific and Technical Information of China (English)

    夏晨

    2012-01-01

      Nowadays, educators from home and abroad believe that learning a foreign language means learning a great deal of the foreign civilization and culture. And the utmost goal of language teaching is to cultivate EFL learners’communicative competence, but not merely the linguistic knowledge. Thus, teaching a foreign language is more than teaching new words, expressions and grammar rules, but should also incorporate the target culture elements into language knowledge. In order to improve EFL learners’English proficiency, teachers must make efforts to cultivate EFL learners’intercultural competence and promote their sensibility and adaptability to the differences between Chinese culture and the Western culture. Only by doing so, can EFL learners communicate with native speakers appropriately and smoothly. This pa-per proposes some effective teaching techniques and methods that can be applied in English classroom to cultivate Chinese EFL learners’in-tercultural competence.

  4. Biofilm-based algal cultivation systems.

    Science.gov (United States)

    Gross, Martin; Jarboe, Darren; Wen, Zhiyou

    2015-07-01

    Biofilm-based algal cultivation has received increased attention as a potential platform for algal production and other applications such as wastewater treatment. Algal biofilm cultivation systems represent an alternative to the suspension-based systems that have yet to become economically viable. One major advantage of algal biofilm systems is that algae can be simply harvested through scraping and thus avoid the expensive harvesting procedures used in suspension-based harvesting such as flocculation and centrifugation. In recent years, an assortment of algal biofilm systems have been developed with various design configurations and biomass production capacities. This review summarizes the state of the art of different algal biofilm systems in terms of their design and operation. Perspectives for future research needs are also discussed to provide guidance for further development of these unique cultivation systems.

  5. Multiple outcomes of cultivation in the Sahel

    DEFF Research Database (Denmark)

    Rasmussen, Laura Vang; Reenberg, Anette

    2015-01-01

    A default assumption about the Sahel is that farmers consider food provision for the family as the sole reason for cultivation. The degree to which this ‘cultivation for food’ assumption has been embedded in the scientific literature on land use changes is signified by the fact that hardly any...... of agriculture in the Global North, the study explores agricultural transitions in two villages in Burkina Faso. The analysis reveals that several household types exist, and one cannot assume that food provision is and always has been the main cultivation outcome. On the contrary, it was found that households...... argues that researchers and policy-makers must face the reality of new agricultural transitional pathways in the Global South....

  6. Long term cultivation of larger benthic Foraminifera

    Science.gov (United States)

    Wöger, Julia; Eder, Wolfgang; Kinoshita, Shunichi; Antonino, Briguglio; Carles, Ferrandes-Cañadell; Hohenegger, Johann

    2015-04-01

    Benthic Foraminifera are used in a variety of applications employing numerous different methods, i.e. ecological monitoring, studying the effects of ocean acidification, reconstructing palaeo-bathymetry or investigating palaeo-salinity and palaeo-temperature to name only a few. To refine our understanding of ecological influences on larger benthic foraminiferal biology and to review inferences from field observations, culture experiments have become an indispensable tool. While culture experiments on smaller benthic foraminifera have become increasingly frequent in the past century, reports of the cultivation of symbiont bearing larger Foraminifera are rare. Generally, cultivation experiments can be divided into two groups: Culturing of populations and cultivation of single specimens allowing individual investigation. The latter differ form the former by several restrictions resulting from the need to limit individual motility without abridging microenvironmental conditions in the Foraminiferans artificial habitat, necessary to enable the individual to development as unfettered as possible. In this study we present first experiences and preliminary results of the long-term cultivation of larger benthic Foraminifera conducted at the 'Tropical Biosphere Research Station Sesoko Island, University of the Ryukyus', Japan, trying to reproduce natural conditions as closely as possible. Individuals of three species of larger benthic Foraminifera (Heterostegina depressa, Palaeonummulites venosus and Operculina complanata) have been cultured since April 2014. At the time of the general assembly the cultivation experiments will have been going on for more than one year, with the aim to investigate growth rates, longevities and reproduction strategies for comparison with results statistically inferred from application of the of the 'natural laboratory' method. The most important factor influencing foraminiferal health and development was found to be light intensity and light

  7. In vitro cultivation of Maritrema novaezealandensis (Microphallidae)

    DEFF Research Database (Denmark)

    Fredensborg, Brian Lund; Poulin, R

    2005-01-01

    and Halicarcinus whitei, were incubated in either: (1) 0.85% saline solution, (2) the commercial cell culture medium, NCTC-109, (3) NCTC-109 supplemented with 20%, or (4) NCTC-109 supplemented with 40% chicken serum. Furthermore, excysted metacercariae were cultured for 5 days in each of the three media: NCTC-109...... cultured in media with a supplement of chicken serum and reached a maximum after 2 days of cultivation. Growth, however, did not occur after the first day of cultivation in any of the three media....

  8. Phenylhydrazines in the cultivated mushroom (Agaricus bisporus)

    DEFF Research Database (Denmark)

    Andersson, H. C.; Gry, Jørn

    2004-01-01

    to provide data for the evaluation of whether the consumption of the cultivated mushroom constitutes a human risk. The present report summarises the Nordic seminar which had the aim to present Nordic studies and to promote exchange of information between chemists and toxicologists in the field of Agaricus...... bisporus research. American, English and Czech researchers gave an up-to-date overview on the cultivated mushroom and its hydrazines and reviewed their ongoing research. Finally, Nordic researchers summarised their chemical and toxicological studies on behalf of the Nordic Project Group on Phenylhydrazines...

  9. HLA-matched living-related conjunctival limbal allograft for bilateral ocular surface disorders: long-term results Transplante alogênico inter vivo de limbo conjuntival com pareamento HLA em doenças bilaterais da superfície ocular: resultados em longo prazo

    Directory of Open Access Journals (Sweden)

    Caio Scocco

    2008-12-01

    Full Text Available PURPOSE: To evaluate the long-term outcome of HLA-matched lr-CLAL for bilateral ocular surface disorders. METHODS: A retrospective, non-comparative interventional case series study of 39 eyes of 32 patients with bilateral surface disorders and clinical diagnosis of limbal stem cell deficiency who underwent HLA-matched lr-CLAL. Visual acuity (VA, ambulatory vision (> 20/200 and ocular surface stability were evaluated as main outcomes. Donor limbus was obtained from a sibling or a parent of the patient, after an appropriate Class I and II HLA match. RESULTS: One year after surgery, VA improved in 46.2%, ambulatory vision was achieved in 48.7% and a stable corneal surface was achieved in 84.6% of the eyes. At the final follow-up (mean, 48.7 ± 30.6 months, 66.6% of the eyes that had gained VA one year after surgery maintained an improved VA (p=0.28, 94.7% of eyes that had achieved ambulatory vision one year after surgery maintained 20/200 or better (pOBJETIVO: Avaliar os resultados em longo prazo do transplante alogênico inter vivo de limbo conjuntival para doenças bilaterais da superfície ocular com compatibilidade HLA doador-receptor. MÉTODOS: Estudo retrospectivo, não comparativo e intervencionista de 39 olhos de 32 pacientes submetidos a transplante alogênico de limbo com compatibilidade HLA e diagnóstico de deficiência límbica. Foram analisados como desfechos principais acuidade visual, visão ambulatorial (> 20/200 e estabilidade da superfície ocular. Limbo doador foi obtido de parentes do paciente após estudo de compatibilidade HLA classe I e II. RESULTADOS: Com um ano de pós-operatório, a acuidade visual melhorou em 46,2%, visão ambulatorial foi atingida em 48,7% e estabilidade da superfície corneana em 84,6% dos pacientes. Ao final do seguimento (média, 48,7 ± 30,6 meses, 66,6% dos olhos que haviam ganho acuidade visual um ano após a cirurgia mantiveram esta melhora (p=0,28, 94,7% dos olhos que haviam alcançado vis

  10. Interactive 3D computer model of the human corneolimbal region

    DEFF Research Database (Denmark)

    Molvaer, Rikke Kongshaug; Andreasen, Arne; Heegaard, Steffen;

    2013-01-01

    in the superior limbal region and one LEC, six LCs and 12 FSPs in the inferior limbal region. Only few LECs, LCs and FSPs were localized nasally and temporally. CONCLUSION: Interactive 3D models are a powerful tool that may help to shed more light on the existence and spatial localization of the different stem......PURPOSE: This study aims to clarify the existence of and to map the localization of different proposed stem cell niches in the corneal limbal region. MATERIALS AND METHODS: One human eye was cut into 2200 consecutive sections. Every other section was stained with haematoxylin and eosin, digitized...... in the limbal region: limbal epithelial crypts (LECs), limbal crypts (LCs) and focal stromal projections (FSPs). In all, eight LECs, 25 LCs and 105 FSPs were identified in the limbal region. The LECs, LCs and FSPs were predominantly located in the superior limbal region with seven LECs, 19 LCs and 93 FSPs...

  11. [Cultivation of pathogenic free-living amoebae].

    Science.gov (United States)

    Peng, Heng; Zhu, Huai-Min

    2009-08-01

    The isolation and culture of pathogenic free-living amoebae are useful in the diagnosis and research. This review focuses on the methods of isolation and cultivation of pathogenic free-living amoebae, including sample treatment, culture conditions, passage culture, pathogen detection, and maintenance.

  12. Cultivation of oyster mushrooms on cassava waste

    NARCIS (Netherlands)

    Sonnenberg, A.S.M.; Baars, J.J.P.; Obodai, M.; Asagbra, A.

    2015-01-01

    Cassava is a major food crop for approximately 700 million people, especially in African countries. A large quantity of waste is produced during processing of cassava, mainly consisting of tuber peels. Although previous research has shown that these peels can be an ingredient for substrate to cultiv

  13. Cultivating adjunct faculty: strategies beyond orientation.

    Science.gov (United States)

    Santisteban, Lisette; Egues, Aida L

    2014-01-01

    Schools of nursing across the country are using adjunct faculty to meet clinical, didactic, and online instructional needs of their nursing programs. While adjunct faculty are vital to the alleviation of the nursing shortage and the shortage of nursing faculty, and to the preparation of the current and future nursing workforce, little is known about cultivating adjunct faculty as nurse educators. To investigate the cultivation of adjunct nursing faculty, the authors engaged in a comprehensive review of the extant literature of primary databases and reports from accredited nursing programs and professional nursing organizations. Scant literature exists that seeks to identify issues associated with developing adjunct nursing faculty as educators, including role transition needs, and useful approaches to orientation, mentorship, or retention. Working toward cultivation of adjunct faculty includes innovative support measures beyond simple orientation. Orientation should be comprehensive, and move to mentorship as a key component that helps establish a sustainable nurse educator career for adjunct nursing faculty. It is incumbent upon schools of nursing to cultivate their adjunct faculty, and this article includes creative approaches to doing so, with recommendations for nursing education, nursing practice, and nursing research settings. While adjunct faculty may successfully meet some of the challenges faced by nursing programs, they themselves face many challenges that may hinder their success as nurse educators. © 2014 Wiley Periodicals, Inc.

  14. Isolation and cultivation of Walsby's square archaeon

    NARCIS (Netherlands)

    Bolhuis, H; Poele, EMT; Rodriguez-Valera, F

    2004-01-01

    In 1980, A. E. Walsby described a square halophilic archaeon. This archaeon is of specific interest because of its unique shape and its abundance in hypersaline ecosystems, which suggests an important ecophysiological role. Ever since its discovery, the isolation and cultivation of 'Walsby's square

  15. Hatchery cultivation of the common cockle (

    NARCIS (Netherlands)

    Pronker, A.E.; Peene, F.; Donner, S.; Wijnhoven, S.; Geijsen, P.; Bossier, P.; Nevejan, N.M.

    2015-01-01

    This study describes for the first time the cultivation of Cerastoderma edule on a commercial scale. A protocol to grow F2 generation cockles was developed, which led to fine-tuning experiments for broodstock conditioning and spat growth.Broodstock animals were conditioned with die

  16. Cultivating Technological Innovation in the Mind

    Directory of Open Access Journals (Sweden)

    PROF ANYATA BENEDICT U.(Ph.D

    2015-11-01

    Full Text Available Cultivating innovation in the mind is imperative to successfully move technology to the next level. Technology is growing rapidly in developed countries and has almost reached its peak. Developing countries and continents like Africa on the other hand are now seen as a breeding ground to explore in technological innovation. Researchers and entrepreneurs are shifting base to Africa where they can achieve maximum profit resulting from under development of the continent. Reefs, city and web are used to explain the best way to cultivate innovation. The city and web are such engines of new innovation because both environments are powerfully suited for the creation, diffusion and adoption of good ideas. The seven keys of cultivating innovation include tropical humidity, illiteracy, poor power surge of electronic use for research, good concept of the liquid networks, slow hunches, serendipity, acceptance of error in cultivating innovation, Exaptation, coffee breaks, application of programming interface and the use of quadrant as a tool. These keys are recommended to be put to use by every individual who has the mindset of driving technological innovation to the next level.

  17. Cultivation Theory and Research: A Conceptual Critique.

    Science.gov (United States)

    Potter, W. James

    1993-01-01

    Presents a critical analysis of how cultivation (long-term formation of perceptions and beliefs about the world as a result of exposure to media) has been conceptualized in theory and research. Analyses the construct of television exposure. Suggests revisions for conceptualizing the existing theory and extending it. (RS)

  18. A study on isolation,cultivation and biological characterisitics of human adipose derived mesenchymal stem cells in vitro%人脂肪间充质干细胞分离培养及其生物学特性的实验研究

    Institute of Scientific and Technical Information of China (English)

    匡世军; 郑有华; 张志光

    2010-01-01

    目的 探索人脂肪间充质干细胞(adipose tissue-derived mesenchymal stem cells,ADMSCs)分离培养的方法 及体外扩增的条件,观察ADMSCs的生物学特性.方法 以腹部手术患者皮下脂防组织为材料,采用Ⅰ型胶原酶消化法及贴壁法分离培养ADMSCs,在含10%胎牛血清的低糖DMEM培养基中贴壁培养,倒置显微镜观察,流式细胞仪检测细胞表面标记CD29、CD44、CD105、CD31、CD34、CD106的表达,透射电镜及扫描电镜下观察ADMSCs超微结构,流式细胞仪测定细胞周期.结果 原代和传代细胞呈梭形外观,生长增殖能力良好.CD29、CD44、CD105均呈阳性表达,阳性率分别为95.3%、98.6%和86.5%;而CD31、CD34、CD106阳性率分别为3.5%、2.6%、1.3%.透射电镜观察显示ADMSCs表现出早期幼稚细胞形态的特点,流式细胞仪检测显示84.8%的细胞处于G0/G1期.结论 酶消化法能有效地从人脂肪组织分离培养人ADSCs,细胞生长稳定,增殖能力活跃,为今后ADMSCs的分离培养提供了更简单有效的方法 .%Objective To explore a practical method for effective isolation and culture of human adipose derived mesenchymal stem cells (ADMSCs) and observe its biological characteristics.Methods Subcutaneous adipose tissue were collected. Primary ADMSCs were isolated subsequently by the method of stirring type Ⅰ collagenase digestion and adhering to culture flask. The morphological changes of ADMSCs were observed under an inserted microscope. The expressions of CD29, CD44, CD105,CD31, CD34, and CD106 were detected by flow cytometry (FCM). Ultrastructure of ADMSCs were observed via electron microscopy. Cell cycle was analyzed by flow cytometry. Results ADSCs in both primary and passage culture were fusiform shapes, and stable in growth with active proliferation. The cells were in latency for 2 days, converted into growth period on day 3 and entered the stable phase on day 5. FCM results indicated that the positive rates of CD29, CD44, CD

  19. Deforestation and cultivation mobilize mercury from topsoil.

    Science.gov (United States)

    Gamby, Rebecca L; Hammerschmidt, Chad R; Costello, David M; Lamborg, Carl H; Runkle, James R

    2015-11-01

    Terrestrial biomass and soils are a primary global reservoir of mercury (Hg) derived from natural and anthropogenic sources; however, relatively little is known about the fate and stability of Hg in the surface soil reservoir and its susceptibility to change as a result of deforestation and cultivation. In southwest Ohio, we measured Hg concentrations in soils of deciduous old- and new-growth forests, as well as fallow grassland and agricultural soils that had once been forested to examine how, over decadal to century time scales, man-made deforestation and cultivation influence Hg mobility from temperate surface soils. Mercury concentrations in surficial soils were significantly greater in the old-growth than new-growth forest, and both forest soils had greater Hg concentrations than cultivated and fallow fields. Differences in Hg:lead ratios between old-growth forest and agricultural topsoils suggest that about half of the Hg lost from deforested and cultivated Ohio soils may have been volatilized and the other half eroded. The estimated mobilization potential of Hg as a result of deforestation was 4.1 mg m(-2), which was proportional to mobilization potentials measured at multiple locations in the Amazon relative to concentrations in forested surface soils. Based on this relationship and an estimate of the global average of Hg concentrations in forested soils, we approximate that about 550 M mol of Hg has been mobilized globally from soil as a result of deforestation during the past two centuries. This estimate is comparable to, if not greater than, the amount of anthropogenic Hg hypothesized by others to have been sequestered by the soil reservoir since Industrialization. Our results suggest that deforestation and soil cultivation are significant anthropogenic processes that exacerbate Hg mobilization from soil and its cycling in the environment. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Cultivation and Biological Characterization of Chicken Primordial Germ Cells

    Directory of Open Access Journals (Sweden)

    Meng Ji

    2016-01-01

    Full Text Available The purpose of this work was to investigate the isolation, culture process of chicken gonadal primordial germ cells (PGCs and study their biological characterization. PGCs were harvested from 5.5-day-old chicken embryonic genital ridges and explanted onto chicken embryonic fibroblasts (CEFs. The results showed that the primary cultivation of chicken PGCs on their own gonadal stroma cells were better than CEFs at first two days for reproduction. The conditioned media supported the growth and colony formation of PGCs for a prolonged time in vitro and maintained a normal diploid karyotype, which were positively stained by alkaline phosphatase (AKP, periodic acid Schiff (PAS and reacted with anti-SSEA-1, SSEA-3, Oct4, Blimp1 and Sox2. Real-time PCR showed that they expressed the stage specific genes CVH, Blimp1 and Dazl, the stem cell specific genes Sox2, Pouv and Nanog. They also formed the embryoid bodies (EBs. These results suggested that the chicken PGCs cultured in vitro not only had strong self-renewal ability, but also had the potential capability of multi-lineage differentiation.

  1. 家兔角膜缘干细胞缺失病理模型的制作%Preparation of pathological model of rabbit total corneal limbal stem cell deficiency

    Institute of Scientific and Technical Information of China (English)

    屈雷; 杨学义; 王馨; 赵明; 窦忠英

    2004-01-01

    根据角膜缘干细胞定位于角膜缘上皮基底层,为角膜上皮增殖分化的源泉并保持角膜上皮完整性的理论.将20只家兔随机分为4组,每组5只,分别将角膜缘上皮全周或半周板层手术切除,或用1 mol/L NaOH直接擦除等方法破坏角膜缘干细胞,探索制作角膜缘干细胞完全缺失病理模型的有效途径.结果表明,处理后4周,全周角膜缘上皮板层手术切除,中央角膜上皮层用1 mol/L NaOH擦除的5只试验家兔角膜表面全部血管化、结膜化,未发生睑球粘连,角膜基质胶原纤维完整未见溃疡、穿孔等病变,细胞印迹学检查为结膜表型,可作为实验性角膜缘干细胞移植的病理模型;全周角膜缘上皮板层手术切除,中央角膜上皮用生理盐水擦除的5只试验家兔,有2只为结膜表型,另3只为角膜表型,观察期内结果不稳定;半周角膜缘上皮板层手术切除,中央角膜上皮层用生理盐水擦除的5只试验家兔,角膜表面透明,全部为角膜表型;直接用1 mol/L NaOH擦除角膜缘和中央角膜上皮的试验家兔,有4只角膜基质胶原纤维断裂、溶解,并伴有严重的溃疡、穿孔、睑球粘连等病变,不能用于移植试验,另1只角膜表面透明,未见结膜和新生血管长入,细胞印迹学检查为角膜表型.

  2. The Impact of Epigenetics on Mesenchymal Stem Cell Biology.

    Science.gov (United States)

    Ozkul, Yusuf; Galderisi, Umberto

    2016-11-01

    Changes in epigenetic marks are known to be important regulatory factors in stem cell fate determination and differentiation. In the past years, the investigation of the epigenetic regulation of stem cell biology has largely focused on embryonic stem cells (ESCs). Contrarily, less is known about the epigenetic control of gene expression during differentiation of adult stem cells (AdSCs). Among AdSCs, mesenchymal stem cells (MSCs) are the most investigated stem cell population because of their enormous potential for therapeutic applications in regenerative medicine and tissue engineering. In this review, we analyze the main studies addressing the epigenetic changes in MSC landscape during in vitro cultivation and replicative senescence, as well as follow osteocyte, chondrocyte, and adipocyte differentiation. In these studies, histone acetylation, DNA methylation, and miRNA expression are among the most investigated phenomena. We describe also epigenetic changes that are associated with in vitro MSC trans-differentiation. Although at the at initial stage, the epigenetics of MSCs promise to have profound implications for stem cell basic and applied research. J. Cell. Physiol. 231: 2393-2401, 2016. © 2016 Wiley Periodicals, Inc.

  3. Stem cell culture engineering - process scale up and beyond.

    Science.gov (United States)

    Sharma, Shikha; Raju, Ravali; Sui, Siguang; Hu, Wei-Shou

    2011-11-01

    Advances in stem cell research and recent work on clinical trials employing stem cells have heightened the prospect of stem cell applications in regenerative medicine. The eventual clinical application of stem cells will require transforming cell production from laboratory practices to robust processes. Most stem cell applications will require extensive ex vivo handling of cells, from isolation, cultivation, and directed differentiation to product cell separation, cell derivation, and final formulation. Some applications require large quantities of cells in each defined batch for clinical use in multiple patients; others may be for autologous use and require only small-scale operations. All share a common requirement: the production must be robust and generate cell products of consistent quality. Unlike the established manufacturing process of recombinant protein biologics, stem cell applications will likely see greater variability in their cell source and more fluctuations in product quality. Nevertheless, in devising stem cell-based bioprocesses, much insight could be gained from the manufacturing of biological materials, including recombinant proteins and anti-viral vaccines. The key to process robustness is thus not only the control of traditional process chemical and physical variables, but also the sustenance of cells in the desired potency or differentiation state through controlling non-traditional variables, such as signaling pathway modulators. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Phytoextraction of weathered p,p'-DDE by zucchini (Cucurbita pepo) and cucumber (Cucumis sativus) under different cultivation conditions.

    Science.gov (United States)

    Wang, Xiaoping; White, Jason C; Gent, Martin P N; Iannucci-Berger, William; Eitzer, Brian D; Mattina, MaryJane Incorvia

    2004-01-01

    Previous studies have shown that zucchini (Cucurbita pepo) and cucumber (Cucumis sativus) under field conditions are good and poor accumulators, respectively, of persistent organic pollutants from soil. Here, each species was grown under three cultivation regimes: dense (five plants in 5 kg soil): nondense (one plant in 80 kg soil): and field conditions (two to three plants in approximately 789 kg soil). p,p'-DDE and inorganic element content in roots, stems, leaves, and fruit were determined. In addition. rhizosphere, near-root, and unvegetated soil fractions were analyzed for concentrations of 11 low-molecular-weight organic acids (LMWOA) and 14 water-extractable inorganic elements. Under field conditions, zucchini phytoextracted 1.3% of the weathered p,p'-DDE with 98% of the contaminant in the aerial tissues. Conversely, cucumber removed 0.09% of the p,p'-DDE under field conditions with 83% in the aerial tissues. Under dense cultivation, cucumber produced a fine and fibrous root system not observed in our previous experiments and phytoextracted 0.78% of the contaminant, whereas zucchini removed only 0.59% under similar conditions. However. cucumber roots translocated only 5.7% of the pollutant to the shoot system, while in zucchini 48% of the p,p'-DDE in the plant was present in the aerial tissue. For each species, the concentrations of LMWOA in soil increased with increasing impact by the root system both within a given cultivation regime (i.e., rhizosphere > near-root > unvegetated) and across cultivation regimes (i.e., dense > nondense > field conditions). Under dense cultivation, the rhizosphere concentrations of LMWOAs were significantly greater for cucumber than for zucchini; no species differences were evident in the other two cultivation regimes. To enable direct comparison across cultivation regimes, total in planta p,p'-DDE and inorganic elements were mass normalized or multiplied by the ratio of plant mass to soil mass. For cucumber, differences in

  5. The Origin of Flooded Rice Cultivation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Rice cultivation has long been considered to have originated from seeding of annual types of wild ricesomewhere in subtropics, tropics or in the Yangtze River basin. That idea, however, contains a fatally weak point, when we consider the tremendous difficulty for primitive human to seed any cereal crop in the warm and humid climate, where weed thrives all year round. Instead of the accepted theory, we have to see a reality that vegetative propagation of edible plants is a dominant form of agriculture in such regions. The possibility is discussed that Job's tears and rice, two cereal crops unique to the region, might have been developed via vegetative propagation to obtain materials for medicine or herb tea in backyard gardens prior to cereal production. This idea is supported by the fact that rice in temperate regions is still perennial in its growth habit and that such backyard gardens with transplanted taro can still be seen from Yunnan Province of China to Laos. Thanks to detailed survey of wild rice throughout China for 1970-1980, it is now confirmed that a set of clones of wild rice exist in shallow swamps in Jiangxi Province, an area with severe winter cold. In early summer ancient farmers may have divided the sprouting buds and spread them by transplanting into flooded shallow marsh. Such way of propagation might have faster improved less productive rice through a better genetic potential for response to human interference than quick fixation in seed propagation, because vegetative parts are heterogeneous. Obviously, such a primitive manner of rice cultivation did include the essential parts of rice farming, i.e., nursery bed, transplanting in flooded field of shallow marsh like. Transfer from the primitive nursery to true nursery by seed may have later allowed rice cultivation to be extended to northern regions. In thus devised flooded cultivation there were a series of unique advantages, i.e.; continuous cropping of rice in a same plot, no soil erosion

  6. The Origin of Flooded Rice Cultivation

    Directory of Open Access Journals (Sweden)

    Hiroshi IKEHASHI

    2007-09-01

    Full Text Available Rice cultivation has long been considered to have originated from seeding of annual types of wild rice somewhere in subtropics, tropics or in the Yangtze River basin. That idea, however, contains a fatally weak point, when we consider the tremendous difficulty for primitive human to seed any cereal crop in the warm and humid climate, where weed thrives all year round. Instead of the accepted theory, we have to see a reality that vegetative propagation of edible plants is a dominant form of agriculture in such regions. The possibility is discussed that Job's tears and rice, two cereal crops unique to the region, might have been developed via vegetative propagation to obtain materials for medicine or herb tea in backyard gardens prior to cereal production. This idea is supported by the fact that rice in temperate regions is still perennial in its growth habit and that such backyard gardens with transplanted taro can still be seen from Yunnan Province of China to Laos. Thanks to detailed survey of wild rice throughout China for 1970–1980, it is now confirmed that a set of clones of wild rice exist in shallow swamps in Jiangxi Province, an area with severe winter cold. In early summer ancient farmers may have divided the sprouting buds and spread them by transplanting into flooded shallow marsh. Such way of propagation might have faster improved less productive rice through a better genetic potential for response to human interference than quick fixation in seed propagation, because vegetative parts are heterogeneous. Obviously, such a primitive manner of rice cultivation did include the essential parts of rice farming, i.e., nursery bed, transplanting in flooded field of shallow marsh like. Transfer from the primitive nursery to true nursery by seed may have later allowed rice cultivation to be extended to northern regions. In thus devised flooded cultivation there were a series of unique advantages, i.e.; continuous cropping of rice in a same

  7. An annotated history of the principles of cultivated plant classification.

    NARCIS (Netherlands)

    Hetterscheid, W.L.A.; Berg, van den R.G.; Brandenburg, W.A.

    1996-01-01

    Important episodes in the history of the classification of cultivated plants are highlighted and commented upon in the light of recent developments in the systematics of cultivated plants. It is shown that throughout history, a division between classifying cultivated plants and plants as found in na

  8. Diversity and biological control of Sclerotium rolfsii, causal agent of stem rot of groundnut

    NARCIS (Netherlands)

    Lê, N.C.

    2011-01-01

    Groundnut (Arachis hypogaea L.) is an economically important legume crop in Vietnam and many other countries worldwide. Stem rot disease, caused by the soil-borne fungus Sclerotium rolfsii Sacc., is a major yield limiting factor in groundnut cultivation. Current control methods

  9. Tracking adult stem cells.

    Science.gov (United States)

    Snippert, Hugo J; Clevers, Hans

    2011-02-01

    The maintenance of stem-cell-driven tissue homeostasis requires a balance between the generation and loss of cell mass. Adult stem cells have a close relationship with the surrounding tissue--known as their niche--and thus, stem-cell studies should preferably be performed in a physiological context, rather than outside their natural environment. The mouse is an attractive model in which to study adult mammalian stem cells, as numerous experimental systems and genetic tools are available. In this review, we describe strategies commonly used to identify and functionally characterize adult stem cells in mice and discuss their potential, limitations and interpretations, as well as how they have informed our understanding of adult stem-cell biology. An accurate interpretation of physiologically relevant stem-cell assays is crucial to identify adult stem cells and elucidate how they self-renew and give rise to differentiated progeny.

  10. Stem Cell Information: Glossary

    Science.gov (United States)

    ... Tips Info Center Research Topics Federal Policy Glossary Stem Cell Information General Information Clinical Trials Funding Information Current ... here Home » Glossary Back to top Glossary Adult stem cell Astrocyte Blastocoel Blastocyst Bone marrow stromal cells Bone ...

  11. Stem Cell Transplant

    Science.gov (United States)

    ... transplant is a procedure that infuses healthy blood stem cells into your body to replace your damaged or ... A bone marrow transplant is also called a stem cell transplant. A bone marrow transplant may be necessary ...

  12. First results of investigations into causes of diseases of cultivated chamomile (Matricaria recutita L. in Germany

    Directory of Open Access Journals (Sweden)

    Gärber, Ute

    2016-07-01

    Full Text Available Diseases on cultivated chamomile have occurred in Germany since 2007, which have severely been affecting the crop yields. The causes of damage are very complex and have not been identified yet. Additionally to the damage in the stems caused by larvae, fungal pathogens are of relevance. Tests of the Julius Kühn-Institute first revealed that a new, not yet identified fungus is pathogenic to chamomile. Symptoms observed in infection tests like chlorosis, browning and black coloration of stems and leaflets were identical to those in the field. The fungus sporulated on diseased plant parts under the conditions of climatic chamber (20 °C to 22 °C and 12 hours of light, 122 μmol from 17 days after inoculation (dai and could be reisolated on agar plates. The identification, biology and epidemiology of the fungus as well as the specific harmful effect and interaction with other harmful factors, especially animal pests, are being studied presently in a project funded by the Agency for Renewable Resources (Fachagentur Nachwachsende Rohstoffe, FNR. The goal is to develop sustainable plant protection concepts based on the knowledge about the pathogens to enable a stable cultivation of chamomile in Germany.

  13. Antioxidant and antimicrobial phenolic compounds from extracts of cultivated and wild-grown Tunisian Ruta chalepensis

    Directory of Open Access Journals (Sweden)

    Ines Ouerghemmi

    2017-04-01

    Full Text Available The antioxidant and antibacterial activities of phenolic compounds from cultivated and wild Tunisian Ruta chalepensis L. leaves, stems, and flowers were assessed. The leaves and the flowers exhibited high but similar total polyphenol, flavonoid, and tannin content. Moreover, two organs showed strong, although not significantly different, total antioxidant activity, 2,2-diphenyl-1-picrylhydrazyl scavenging ability, and reducing power. Investigation of the phenolic composition showed that vanillic acid and coumarin were the major compounds in the two organs, with higher percentages in the cultivated organs than in the spontaneous organs. Furthermore, R. chalepensis extracts showed marked antibacterial properties against human pathogen strains, and the activity was organ- and origin-dependent. Spontaneous stems had the strongest activity against Pseudomonas aeruginosa. From these results, it was concluded that domestication of Ruta did not significantly affect its chemical composition and consequently the possibility of using R. chalpensis organs as a potential source of natural antioxidants and as an antimicrobial agent in the food industry.

  14. Cultivation of microalgae in industrial wastewaters

    DEFF Research Database (Denmark)

    van Wagenen, Jonathan Myerson

    Microalgae production for the purpose of clearing wastewater has been researched for at least half a century. Such systems have a dual benefit: first, they prevent nutrients from entering water bodies and causing eutrophication; second, they transform sunlight and carbon dioxide into a biomass...... to a growing body of knowledge with the aim to make algae cultivation viable for the production of sustainable products. Specific contributions include: improvement in the methods of screening the growth potential of different microalgae species; identification of an industrial wastewater that allows good...... is that there are many potential combinations which must empirically screened. Tens of thousands of microalgae species have been identified so far and there are numerous waste-streams that potentially could be of interest. A screening system was developed using the microplate as cultivation vessel and measurement...

  15. The Cultivation of Good Personalities In University

    Institute of Scientific and Technical Information of China (English)

    刘群

    2008-01-01

    This is a thesis on quality education of Chinese college students in the new century.She proves the significance of cultivation of persorlalities.It takes four kinds of personalities as examples.They are confidence,do-it-yourself spirit,down-to-earth spirit and cooperative personality.It declares their importance,meaning and cultivated approaches.It adopts the experience of social people,experiment of phycology and research of other universities.There are three purposes of this thesis.The first one is to give a guide to enrich their own campus life.The second is to improve the qualitv education of college.It is also answering the call of development of the society.

  16. Tracking adult stem cells

    NARCIS (Netherlands)

    Snippert, H.J.G.; Clevers, H.

    2011-01-01

    The maintenance of stem-cell-driven tissue homeostasis requires a balance between the generation and loss of cell mass. Adult stem cells have a close relationship with the surrounding tissue--known as their niche--and thus, stem-cell studies should preferably be performed in a physiological context,

  17. Fungi colonizing various organs of thyme Thymus vulgaris L. cultivated in the region of Lublin

    Directory of Open Access Journals (Sweden)

    Zofia Machowicz-Stefaniak

    2013-12-01

    Full Text Available In 1998-2001, the healthiness of thyme cultivated in the region of Lublin was examined. Surveys were made on the one-year-old plantations of thyme at a stage of 6-week-old seedlings and just before the first harvest of the crop, as well as on the two-year-old plantations in spring and before the last harvest. The percentage of the plants showing fungal disease symptoms and the index of infection with fungi were determined. The fungi were isolated from superficially disinfected plant fragments namely from roots, bases of stem and leaves, separately, using mineral culture medium. PDA and SNA media were used to culture Fusarium spp., malt-agar and Czapek-Dox ones to culture Penicillium spp. and malt-agar, oat-agar and cherry-agar ones to culture Phoma spp. The percentage of plant infected with the fungi ranged within 12.18 and 23.05, in case of the one-year-old plantations, and within 29.91 and 43.65 in the two-year-old ones, whereas values of the index of infection ranged within 11.56 and 24.69 and within 20.75 and 43,28, respectively. Necroses were observed on roots and base of stems on one-year-old and two-year-old plantations, but in the last period of vegetation of thyme close to harvest. very often stems and leaves showed symptoms of a complete necrosis. It was found that base of stems and roots of thyme in the first and the second year of cultivation were colonized by a complex of pathogenic fungi:Fusarium spp., Rhizoctonia solani, Thielaviopsis basicola were obtained from the major part of diseased plants. Among the Fusarium species colonizing bases of stems F.culmorum, F.avenaceum, F.equiseti and F.oxysporum dominated, but from roots of thyme most often F.oxysporum, F.equiseti and F.culmorum were isolated. From stems, and particularly from leaves of thyme showing dark spots, commonly Alternaria alternata was obtained. On the other hand, shoots and leaves, but rarely roots of thyme, were colonized by various species of Phoma, particularly

  18. Eucheuma and Kappaphycus : taxonomy and cultivation

    OpenAIRE

    Trono, Jr., C. Gavino

    1992-01-01

    The Genera Eucheuma, Kappaphycus and Hypnea are three important genera of carrageenophytes which are abundant in the Philippines and in the tropical Asia and Western Pacific. The most useful species for the source of kappa carageenan is K. alvarezii called E. "cottonii" of commerce. E. denticulatum called E. "spinosum" of commerce is also the most useful species for the sources of iota carrageenan.The different methods of Eucheuma cultivation were tried in the past from very simple bottom cul...

  19. Cultivation of alfalfa (medicago sativa L).

    Science.gov (United States)

    Rashmi, R; Sarkar, M; Vikramaditya

    1997-10-01

    Madicago sativa Linn, commonly known as 'Alfalfa', is a tonic plant rich in proteins, minerals, enzymes and vitamins, Bulk quantity of the whole plant is required in the pharmaceutical industries especially in homoecopathic pharmacies, Hence, there is a great need to cultivate this plant for sustained supply of the drug. Use of good and adequate phosphatecontaining farm yard manure, timely irrigation and appropriate spacing between plants results in good yield.

  20. Human Colon Cancer Cells Cultivated in Space

    Science.gov (United States)

    1995-01-01

    Within five days, bioreactor cultivated human colon cancer cells (shown) grown in Microgravity on the STS-70 mission in 1995, had grown 30 times the volume of the control specimens on Earth. The samples grown in space had a higher level of cellular organization and specialization. Because they more closely resemble tumors found in the body, microgravity grown cell cultures are ideal for research purposes.

  1. Morphology and rheology in filamentous cultivations.

    Science.gov (United States)

    Wucherpfennig, T; Kiep, K A; Driouch, H; Wittmann, C; Krull, R

    2010-01-01

    Because of their metabolic diversity, high production capacity, secretion efficiency, and capability of carrying out posttranslational modifications, filamentous fungi are widely exploited as efficient cell factories in the production of metabolites, bioactive substances, and native or heterologous proteins, respectively. There is, however, a complex relationship between the morphology of these microorganisms, transport phenomena, the viscosity of the cultivation broth, and related productivity. The morphological characteristics vary between freely dispersed mycelia and distinct pellets of aggregated biomass, every growth form having a distinct influence on broth rheology. Hence, the advantages and disadvantages for mycelial or pellet cultivation have to be balanced out carefully. Because of the still inadequate understanding of the morphogenesis of filamentous microorganisms, fungal morphology is often a bottleneck of productivity in industrial production. To obtain an optimized production process, it is of great importance to gain a better understanding of the molecular and cell biology of these microorganisms as well as the relevant approaches in biochemical engineering. In this chapter, morphology and growth of filamentous fungi are described, with special attention given to specific problems as they arise from fungal growth forms; growth and mass transfer in fungal biopellets are discussed as an example. To emphasize the importance of the flow behavior of filamentous cultivation broths, an introduction to rheology is also given, reviewing important rheological models and recent studies concerning rheological parameters. Furthermore, current knowledge on morphology and productivity in relation to the environom is outlined in the last section of this review. Copyright 2010 Elsevier Inc. All rights reserved.

  2. Cultivation of Pleurotus ostreatus on weed plants.

    Science.gov (United States)

    Das, Nirmalendu; Mukherjee, Mina

    2007-10-01

    Oyster mushroom, Pleurotus ostreatus (Jacq.:Fr.) Kumm. ITCC 3308 (collected from Indian Type Culture Collection, IARI, New Delhi, India, 110012) was grown on dry weed plants, Leonotis sp, Sida acuta, Parthenium argentatum, Ageratum conyzoides, Cassia sophera, Tephrosia purpurea and Lantana camara. Leonotis sp. was the best substrate in fruit body production of P. ostreatus when it was mixed with rice straw (1:1, wet wt/wet wt) for mushroom cultivation. The fruiting time for P. ostreatus was also less on Leonotis sp. than on any other weed substrates tested in the present investigation. T. purpurea was the least suited weed for oyster mushroom cultivation. The main problem of oyster mushroom cultivation on weed substrates was found to be low yield in the second flush that could be overcome by blending weed plants with rice straw. The protein contents of the fruit bodies obtained from Cassia sophera, Parthenium argentatum and Leonotis sp. were not only better than rice straw but also from the rice straw supplemented weeds.

  3. Use of waste material in cultivation substrates

    Directory of Open Access Journals (Sweden)

    Petr Salaš

    2004-01-01

    Full Text Available Gardeners' practical experience and experimental work prove the affirmation that the used substrate is a very important base for the production of quality nursery products. It is important to emphasis the complexity and synergy of all factors influencing the ecosystem and there mutual relations. Physical, chemical and biological properties do not separately affect the growth and development of plants. In addition, the relations are not statical but differ in relation with other factors changes. This article is dealing with the possibility to use waste material from timber processing in cultivation substrates. The large scale use of such substrates would enable people to reach a relative independence from peat substrates, of which the global reserve is gradually decreasing.Our research activities focus on the use of bark. The basic problems of a bark substrate are easy dehydration and unbalanced nutrition of trees and shrubs. The suggested and experimented cultivation technology solves these problems. It is based on the cultivation of woody species in bark substrates, using modern irrigation systems, slow release fertilisers (Silvamix Forte and special soil conditioners (TerraCottem. This technology was tested on the following species of trees and shrubs: Malus and Buxus.

  4. Short-term and long-term clinostat and vibration-induced biochemical changes in dwarf marigold stems

    Science.gov (United States)

    Siegel, S. M.; Siegel, B. Z.

    1983-01-01

    Stems of 21-day dwarf marigold plants cultivated on the clinostat were compared with plants cultivated on vertical axis rotators ('vibrational controls') and stationary controls for long-term changes in cell wall composition. Stems of 21-day plants grown under stationary conditions and subsequently exposed to the clinostat for 24 hours were also analyzed. Among the long-term markers, calcium, lignin, and protein-bound hemicellulose (possibly cell wall glycoprotein) clearly differentiated the effects of vibration from those of the clinostat. Short-term differential responses included rate of ethylene production, nastic movement and peroxidase activity of the cell wall, but not of the protoplast.

  5. Mesenchymal stem cell subpopulations: phenotype, property and therapeutic potential.

    Science.gov (United States)

    Mo, Miaohua; Wang, Shan; Zhou, Ying; Li, Hong; Wu, Yaojiong

    2016-09-01

    Mesenchymal stem cells (MSC) are capable of differentiating into cells of multiple cell lineages and have potent paracrine effects. Due to their easy preparation and low immunogenicity, MSC have emerged as an extremely promising therapeutic agent in regenerative medicine for diverse diseases. However, MSC are heterogeneous with respect to phenotype and function in current isolation and cultivation regimes, which often lead to incomparable experimental results. In addition, there may be specific stem cell subpopulations with definite differentiation capacity toward certain lineages in addition to stem cells with multi-differentiation potential. Recent studies have identified several subsets of MSC which exhibit distinct features and biological activities, and enhanced therapeutic potentials for certain diseases. In this review, we give an overview of these subsets for their phenotypic, biological and functional properties.

  6. Detoxification of phytotoxic compounds by TiO2 photocatalysis in a recycling hydroponic cultivation system of asparagus.

    Science.gov (United States)

    Sunada, Kayano; Ding, Xin Geng; Utami, Melia Sandya; Kawashima, Yoko; Miyama, Yoko; Hashimoto, Kazuhito

    2008-06-25

    TiO 2 photocatalytic decomposition and detoxification of phytotoxic compounds released by the roots of asparagus ( Asparagus officinalis L.) were investigated from the viewpoint of conservation-oriented cultivation. The phytotoxically active fraction was extracted either from dried asparagus roots or from the recycled nutrient solution of an asparagus hydroponic cultivation system. We found that the phytotoxic activity gradually decreased in the fraction with TiO 2 powder under irradiation with ultraviolet (UV) light at an intensity of 1.0 mW/cm (2). The growth of asparagus plants under actual cultivation conditions was also investigated by comparing asparagus grown in a hydroponic system where recycled waste nutrient solution was photocatalytically treated with solar light and a system with untreated recycled waste nutrient solution. The results showed, as measured by growth indices such as stem length and stem thickness, that asparagus growth in the photocatalytically treated system was superior to the untreated one. Furthermore, the yield of asparagus spears was 1.6-fold greater in the photocatalytically treated system, demonstrating the detoxification effect on the phytotoxic compounds and also the killing effect on pathogenic microorganisms.

  7. Lung Cancer Stem Cells

    Directory of Open Access Journals (Sweden)

    Sharon R. Pine

    2008-01-01

    Full Text Available Lung cancer remains a major cause of cancer-related lethality because of high incidence and recurrence in spite of significant advances in staging and therapies. Recent data indicates that stem cells situated throughout the airways may initiate cancer formation. These putative stem cells maintain protumorigenic characteristics including high proliferative capacity, multipotent differentiation, drug resistance and long lifespan relative to other cells. Stem cell signaling and differentiation pathways are maintained within distinct cancer types, and destabilization of this machinery may participate in maintenance of cancer stem cells. Characterization of lung cancer stem cells is an area of active research and is critical for developing novel therapies. This review summarizes the current knowledge on stem cell signaling pathways and cell markers used to identify the lung cancer stem cells.

  8. Plant stem cell niches.

    Science.gov (United States)

    Aichinger, Ernst; Kornet, Noortje; Friedrich, Thomas; Laux, Thomas

    2012-01-01

    Multicellular organisms possess pluripotent stem cells to form new organs, replenish the daily loss of cells, or regenerate organs after injury. Stem cells are maintained in specific environments, the stem cell niches, that provide signals to block differentiation. In plants, stem cell niches are situated in the shoot, root, and vascular meristems-self-perpetuating units of organ formation. Plants' lifelong activity-which, as in the case of trees, can extend over more than a thousand years-requires that a robust regulatory network keep the balance between pluripotent stem cells and differentiating descendants. In this review, we focus on current models in plant stem cell research elaborated during the past two decades, mainly in the model plant Arabidopsis thaliana. We address the roles of mobile signals on transcriptional modules involved in balancing cell fates. In addition, we discuss shared features of and differences between the distinct stem cell niches of Arabidopsis.

  9. Interaction of adult human neural crest-derived stem cells with a nanoporous titanium surface is sufficient to induce their osteogenic differentiation

    Directory of Open Access Journals (Sweden)

    Matthias Schürmann

    2014-07-01

    Full Text Available Osteogenic differentiation of various adult stem cell populations such as neural crest-derived stem cells is of great interest in the context of bone regeneration. Ideally, exogenous differentiation should mimic an endogenous differentiation process, which is partly mediated by topological cues. To elucidate the osteoinductive potential of porous substrates with different pore diameters (30 nm, 100 nm, human neural crest-derived stem cells isolated from the inferior nasal turbinate were cultivated on the surface of nanoporous titanium covered membranes without additional chemical or biological osteoinductive cues. As controls, flat titanium without any topological features and osteogenic medium was used. Cultivation of human neural crest-derived stem cells on 30 nm pores resulted in osteogenic differentiation as demonstrated by alkaline phosphatase activity after seven days as well as by calcium deposition after 3 weeks of cultivation. In contrast, cultivation on flat titanium and on membranes equipped with 100 nm pores was not sufficient to induce osteogenic differentiation. Moreover, we demonstrate an increase of osteogenic transcripts including Osterix, Osteocalcin and up-regulation of Integrin β1 and α2 in the 30 nm pore approach only. Thus, transplantation of stem cells pre-cultivated on nanostructured implants might improve the clinical outcome by support of the graft adherence and acceleration of the regeneration process.

  10. Preparing Students for Middle School Through After-School STEM Activities

    Science.gov (United States)

    Moreno, Nancy P.; Tharp, Barbara Z.; Vogt, Gregory; Newell, Alana D.; Burnett, Christopher A.

    2016-09-01

    The middle school years are a crucial time for cultivating students' interest in and preparedness for future STEM careers. However, not all middle school children are provided opportunities to engage, learn and achieve in STEM subject areas. Engineering, in particular, is neglected in these grades because it usually is not part of science or mathematics curricula. This study investigates the effectiveness of an engineering-integrated STEM curriculum designed for use in an after-school environment. The inquiry-based activities comprising the unit, Think Like an Astronaut, were intended to introduce students to STEM careers—specifically engineering and aerospace engineering—and enhance their skills and knowledge applicable related to typical middle school science objectives. Results of a field test with a diverse population of 5th grade students in nine schools revealed that Think Like an Astronaut lessons are appropriate for an after-school environment, and may potentially help increase students' STEM-related content knowledge and skills.

  11. Preparing Students for Middle School Through After-School STEM Activities

    Science.gov (United States)

    Moreno, Nancy P.; Tharp, Barbara Z.; Vogt, Gregory; Newell, Alana D.; Burnett, Christopher A.

    2016-12-01

    The middle school years are a crucial time for cultivating students' interest in and preparedness for future STEM careers. However, not all middle school children are provided opportunities to engage, learn and achieve in STEM subject areas. Engineering, in particular, is neglected in these grades because it usually is not part of science or mathematics curricula. This study investigates the effectiveness of an engineering-integrated STEM curriculum designed for use in an after-school environment. The inquiry-based activities comprising the unit, Think Like an Astronaut, were intended to introduce students to STEM careers—specifically engineering and aerospace engineering—and enhance their skills and knowledge applicable related to typical middle school science objectives. Results of a field test with a diverse population of 5th grade students in nine schools revealed that Think Like an Astronaut lessons are appropriate for an after-school environment, and may potentially help increase students' STEM-related content knowledge and skills.

  12. Microfluidic devices for cell cultivation and proliferation

    OpenAIRE

    Tehranirokh, Masoomeh; Kouzani, Abbas Z.; Francis, Paul S.; Kanwar, Jagat R.

    2013-01-01

    Microfluidic technology provides precise, controlled-environment, cost-effective, compact, integrated, and high-throughput microsystems that are promising substitutes for conventional biological laboratory methods. In recent years, microfluidic cell culture devices have been used for applications such as tissue engineering, diagnostics, drug screening, immunology, cancer studies, stem cell proliferation and differentiation, and neurite guidance. Microfluidic technology allows dynamic cell cul...

  13. Cultivation of different strains of king oyster mushroom (Pleurotus eryngii) on saw dust and rice straw in Bangladesh

    Science.gov (United States)

    Moonmoon, Mahbuba; Uddin, Md. Nazim; Ahmed, Saleh; Shelly, Nasrat Jahan; Khan, Md. Asaduzzaman

    2010-01-01

    Pleurotus eryngii is a popular mushroom due to its excellent consistency of cap and stem, culinary qualities and longer shelf life. In Bangladesh, where Pleurotus mushrooms are very popular, P. eryngii may take position among the consumers, but currently this mushroom is not cultivated in large scale there. In this study, 3 strains of P. eryngii such as Pe-1 (native to Bangladesh), Pe-2 (germplasm collected from China) and Pe-3 (germplasm collected from Japan) were cultivated on saw dust and rice straw and their growth and yield parameters were investigated. Pe-1 on saw dust showed the highest biological yield and efficiency (73.5%) than other strains. Also, the mycelium run rate and number of fruiting bodies were higher in Pe-1 than other two strains. The quality of mushroom strains was near about similar. On saw dust, the yield and efficiency were better than those cultivated on rice straw, however, on straw; the mushroom fruiting bodies were larger in size. This study shows the prospects of P. eryngii cultivation in Bangladesh and suggests further study in controlled environment for higher yield and production. PMID:23961095

  14. Clinical application of fibrin glue for attaching limbal-conjunctival autograft after pterygium blunt dissection%翼状胬肉钝性剥离联合纤维蛋白胶固定自体角膜缘干细胞移植术的临床应用

    Institute of Scientific and Technical Information of China (English)

    韩文杰; 崔波; 宋艳玲; 徐教伦

    2012-01-01

    目的 观察翼状胬肉钝性剥离联合纤维蛋白胶固定自体角膜缘干细胞移植术治疗翼状胬肉的临床效果,评价纤维蛋白胶固定球结膜移植片的有效性和安全性.方法 对原发性鼻侧翼状胬肉患者(20只眼)行翼状胬肉钝性剥离联合纤维蛋白胶固定自体角膜缘干细胞移植术,术中钝性剥离翼状胬肉头部,并采用纤维蛋白胶固定球结膜移植片,术后随访6个月.结果 所有患者的球结膜移植片均成功固定于巩膜表面,并全部成活;平均手术时间(20.5±3.6)min;术后患者的疼痛、异物感、流泪等刺激症状轻微;随访期间所有病例均无复发.结论 翼状胬肉钝性剥离联合纤维蛋白胶固定自体角膜缘干细胞移植术是一种安全、有效、较为理想的手术方式,手术时间短,术后患者刺激症状轻微.%OBJECTIVE To observe the effect of clinical application of fibrin glue for attaching limbal-con-junctival autograft after pterygium blunt dissection,and assess the efficiency and safety of using a fibrin glue to adhere the limbal-conjunctival autograft. METHODS Twenty patients (20 eyes) with primary nasal pterygium were subjected to limbal-conjunctival autografts surgery. The pterygium was blunt dissected and the autograft was fixed to the bare sclera using the fibrin glue. The follow-up period was 6 months. RESULTS All limbal-conjunctival autografts in this group were successfully fixed and intact during the 6 months. The time of surgery was 20.5±3.6 minutes. Sbjective symptoms of pain, foreign body sensation and watering were mild. There were no cases of recurrence of the pterygium. CONCLUSIONS The method of application of fibrin glue for attaching limbal-conjunctival autograft after pterygium blunt dissection was safe and effective. This technique could reduce the time of surgery and avoid the sensation of irritation.

  15. Uranium uptake by hydroponically cultivated crop plants

    Energy Technology Data Exchange (ETDEWEB)

    Soudek, Petr; Petrova, Sarka [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Rozvojova 263, 162 05 Prague 6 (Czech Republic); Benesova, Dagmar [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Rozvojova 263, 162 05 Prague 6 (Czech Republic); Faculty of Environment Technology, Institute of Chemical Technology, Technicka 5, 166 28 Prague 6 (Czech Republic); Dvorakova, Marcela [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Rozvojova 263, 162 05 Prague 6 (Czech Republic); Vanek, Tomas, E-mail: vanek@ueb.cas.cz [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Rozvojova 263, 162 05 Prague 6 (Czech Republic)

    2011-06-15

    Hydroponicaly cultivated plants were grown on medium containing uranium. The appropriate concentrations of uranium for the experiments were selected on the basis of a standard ecotoxicity test. The most sensitive plant species was determined to be Lactuca sativa with an EC{sub 50} value about 0.1 mM. Cucumis sativa represented the most resistant plant to uranium (EC{sub 50} = 0.71 mM). Therefore, we used the uranium in a concentration range from 0.1 to 1 mM. Twenty different plant species were tested in hydroponic solution supplemented by 0.1 mM or 0.5 mM uranium concentration. The uranium accumulation of these plants varied from 0.16 mg/g DW to 0.011 mg/g DW. The highest uranium uptake was determined for Zea mays and the lowest for Arabidopsis thaliana. The amount of accumulated uranium was strongly influenced by uranium concentration in the cultivation medium. Autoradiography showed that uranium is mainly localized in the root system of the plants tested. Additional experiments demonstrated the possibility of influencing the uranium uptake from the cultivation medium by amendments. Tartaric acid was able to increase uranium uptake by Brassica oleracea and Sinapis alba up to 2.8 times or 1.9 times, respectively. Phosphate deficiency increased uranium uptake up to 4.5 times or 3.9 times, respectively, by Brassica oleracea and S. alba. In the case of deficiency of iron or presence of cadmium ions we did not find any increase in uranium accumulation. - Highlights: > The uranium accumulation in twenty different plant species varied from 0.160 to 0.011 mg/g DW. > Uranium is mainly localized in the root system. > Tartaric acid was able to increase uranium uptake by Brassica oleracea and Sinapis alba. > The phosphates deficiency increase the uranium uptake.

  16. Expression Patterns of Cancer-Testis Antigens in Human Embryonic Stem Cells and Their Cell Derivatives Indicate Lineage Tracks

    OpenAIRE

    Nadya Lifantseva; Anna Koltsova; Tatyana Krylova; Tatyana Yakovleva; Galina Poljanskaya; Olga Gordeeva

    2011-01-01

    Pluripotent stem cells can differentiate into various lineages but undergo genetic and epigenetic changes during long-term cultivation and, therefore, require regular monitoring. The expression patterns of cancer-testis antigens (CTAs) MAGE-A2, -A3, -A4, -A6, -A8, -B2, and GAGE were examined in undifferentiated human embryonic stem (hES) cells, their differentiated derivatives, teratocarcinoma (hEC) cells, and cancer cell lines of neuroectodermal and mesodermal origin. Undifferentiated hES ce...

  17. Keratinocyte Growth Factor-2 on the Proliferation of Corneal Epithelial Stem Cells in Rabbit Alkali Burned Cornea

    Institute of Scientific and Technical Information of China (English)

    Liu; Yongping; Shuqi; Huang; Jianxian; Lin; Wenxin; Zhang

    2007-01-01

    epithelium than in the controls. The P63 positive cells in the alkali burned epithelium were found not only in the limbal area but also in the central cornea. In addition, the number of stem cells in each group came to the maximum on the 14th day. For example, on the 7th day after alkali injury, it was 40.3±2.1 NPC in the non-limbal area of 50 μg/ml KGF-2-treated group; whereas, it was 84.8±2.7 NPC on the 14th day(P= 0.000).Conclusions: From the daily evaluation of the corneal surface as well as the microscopic examinations at the end of the three periods of observation, we concluded that KGF-2 provided a beneficial effect in the treatment of alkali burns of the cornea.Furthermore, the results of epithelial stem cell analysis demonstrated that KGF-2 accelerated the corneal epithelial healing by markedly stimulating epithelial stem cells proliferation and making them migrate to the central cornea.

  18. Origin, dispersal, cultivation and variation of rice.

    Science.gov (United States)

    Khush, G S

    1997-09-01

    There are two cultivated and twenty-one wild species of genus Oryza. O. sativa, the Asian cultivated rice is grown all over the world. The African cultivated rice, O. glaberrima is grown on a small scale in West Africa. The genus Oryza probably originated about 130 million years ago in Gondwanaland and different species got distributed into different continents with the breakup of Gondwanaland. The cultivated species originated from a common ancestor with AA genome. Perennial and annual ancestors of O. sativa are O. rufipogon and O. nivara and those of O. glaberrima are O. longistaminata, O. breviligulata and O. glaberrima probably domesticated in Niger river delta. Varieties of O. sativa are classified into six groups on the basis of genetic affinity. Widely known indica rices correspond to group I and japonicas to group VI. The so called javanica rices also belong to group VI and are designated as tropical japonicas in contrast to temperate japonicas grown in temperate climate. Indica and japonica rices had a polyphyletic origin. Indicas were probably domesticated in the foothills of Himalayas in Eastern India and japonicas somewhere in South China. The indica rices dispersed throughout the tropics and subtropics from India. The japonica rices moved northward from South China and became the temperate ecotype. They also moved southward to Southeast Asia and from there to West Africa and Brazil and became tropical ecotype. Rice is now grown between 55 degrees N and 36 degrees S latitudes. It is grown under diverse growing conditions such as irrigated, rainfed lowland, rainfed upland and floodprone ecosystems. Human selection and adaptation to diverse environments has resulted in numerous cultivars. It is estimated that about 120,000 varieties of rice exist in the world. After the establishment of International Rice Research Institute in 1960, rice varietal improvement was intensified and high yielding varieties were developed. These varieties are now planted to 70

  19. Cultivating nursing leadership for our envisioned future.

    Science.gov (United States)

    Galuska, Lee A

    2012-01-01

    Nurses have been called upon to lead and partner in the transformation of health care. Leadership is a component of the scope of nursing practice; however, the optimal approach to development of leadership competency has not been established. A metasynthesis of qualitative studies on leadership development was conducted to enhance an understanding of conditions that nurses reported to support or hinder their development as leaders. Noblit and Hare's approach was used for the metasynthesis process. Three overarching themes emerged. Opportunity structure, the relationship factor, and organizational culture are essential factors contributing to the successful cultivation of leadership competencies in nurses.

  20. Contact-free single-cell cultivation by negative dielectrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, Magnus S; Uhlig, Katja [Fraunhofer Institute for Biomedical Engineering (IBMT), Am Muehlenberg 13, 14476 Potsdam (Germany); Schnelle, Thomas [Zimmermann and Partner, European Patent Attorneys, Oranienburger Strasse 90, 10178 Berlin (Germany); Mueller, Torsten [JPK Instruments AG, Aufgang C, Haus 2, Bouchestrasse 12, 12435 Berlin (Germany)], E-mail: magnus.jaeger@ibmt.fraunhofer.de

    2008-09-07

    In parallel to recent progress of high-content analysis in cell biology, negative dielectrophoresis (nDEP) has continuously evolved as a potent tool for contact-free manipulation and investigation of single cells. As such, it can be especially beneficial for the handling of rare and valuable cells, e.g. in stem cell research, immunology and autologous therapy. Current nDEP applications are mainly based on flow-through systems where a small volume or single cells are pumped through microfluidic channels and analysed in seconds to minutes. Such short-term electric field exposures were repeatedly shown to be physiologically harmless. Conditions, however, might change in longer experiments when damages may accumulate. Therefore, we focus on potential limits to long-term nDEP application, with yeast serving as a model organism. Cells are reported to be successfully cultivated over several hours while suspended contact-freely in cell medium by nDEP. From comparisons of the cell division in nDEP structures under different electric conditions, conclusions are drawn with respect to which parameters govern the possible stress on the cells and how to avoid it. Firstly, the observed frequency dependence hints at an influence of the membrane polarization. Secondly, the inhibition of proliferation at high voltages is found to be overcome by external cooling of the microchips. This implies thermal effects on the cells. The warming is further examined by infrared (IR) thermometry. Despite its inherent drawbacks, IR provides a quick and easy method of determining the temperature of microfluidic systems without interfering local probes or reporter substances.

  1. [Effects of substrate-aeration cultivation pattern on tomato growth].

    Science.gov (United States)

    Zhao, Xu; Li, Tian-Lai; Sun, Zhou-Ping

    2010-01-01

    Aeroponics can increase the fruit yield of tomato plant, but its cost is very high. In this paper, tomato seedlings were planted with three cultures, i. e., whole perlite culture (CK), perlite-aeration culture (T1), and aeroponics (T2), and a comparative study was made on the seedlings growth. Compared with CK, T1 improved the gas environment in root zone significantly, with the CO2 and O2 concentrations in root zone being 0.2 and 1.17 times higher, and increased the plant height and stem diameter after 60 days of transplanting by 5.1% and 8.4%, respectively. The plant net photosynthetic rate of T1 was significantly higher than that of CK, with the maximum value after transplanting 45 days increased by 13%. T1 also increased the root activity and ion absorbing ability significantly, with the root activity after transplanting 45 days being 1.23 times of CK, and the root K, Ca, and Mg contents after transplanting 60 days increased by 31%, 37%, and 27%, respectively. The fruit yield of T1 was 1.16 times of CK. No significant differences in these indices were observed between T1 and T2, and less difference in the fruit soluble sugar and organic acid contents as well as the sugar-acid ratio was found among CK, T1, and T2. It was suggested that perlite-aeration cultivation pattern was an easy and feasible way to markedly improve the fruit yield of tomato plant.

  2. Functional state modelling approach validation for yeast and bacteria cultivations

    Science.gov (United States)

    Roeva, Olympia; Pencheva, Tania

    2014-01-01

    In this paper, the functional state modelling approach is validated for modelling of the cultivation of two different microorganisms: yeast (Saccharomyces cerevisiae) and bacteria (Escherichia coli). Based on the available experimental data for these fed-batch cultivation processes, three different functional states are distinguished, namely primary product synthesis state, mixed oxidative state and secondary product synthesis state. Parameter identification procedures for different local models are performed using genetic algorithms. The simulation results show high degree of adequacy of the models describing these functional states for both S. cerevisiae and E. coli cultivations. Thus, the local models are validated for the cultivation of both microorganisms. This fact is a strong structure model verification of the functional state modelling theory not only for a set of yeast cultivations, but also for bacteria cultivation. As such, the obtained results demonstrate the efficiency and efficacy of the functional state modelling approach. PMID:26740778

  3. Functional state modelling approach validation for yeast and bacteria cultivations.

    Science.gov (United States)

    Roeva, Olympia; Pencheva, Tania

    2014-09-03

    In this paper, the functional state modelling approach is validated for modelling of the cultivation of two different microorganisms: yeast (Saccharomyces cerevisiae) and bacteria (Escherichia coli). Based on the available experimental data for these fed-batch cultivation processes, three different functional states are distinguished, namely primary product synthesis state, mixed oxidative state and secondary product synthesis state. Parameter identification procedures for different local models are performed using genetic algorithms. The simulation results show high degree of adequacy of the models describing these functional states for both S. cerevisiae and E. coli cultivations. Thus, the local models are validated for the cultivation of both microorganisms. This fact is a strong structure model verification of the functional state modelling theory not only for a set of yeast cultivations, but also for bacteria cultivation. As such, the obtained results demonstrate the efficiency and efficacy of the functional state modelling approach.

  4. Many facets of stem cells

    Institute of Scientific and Technical Information of China (English)

    Jiarui Wu

    2011-01-01

    @@ Research area on stem cells is one of frontiers in biology.The collection of five research articles in this issue aims to cover timely developments in stem cell biology, ranging from generating and identifying stem cell line to manipulating stem cells, and from basic mechanism analysis to applied medical potential.These papers reflect the various research tasks in stem cell biology.

  5. Optimisation of cultivation parameters in photobioreactors for microalgae cultivation using the A-stat technique

    NARCIS (Netherlands)

    Barbosa, M.J.; Hoogakker, J.; Wijffels, R.H.

    2003-01-01

    Light availability inside the reactor is often the bottleneck in microalgal cultivation and for this reason much attention is being given to light limited growth kinetics of microalgae, aiming at the increase of productivity in photobioreactors. Steady-state culture characteristics are commonly used

  6. Global Collaborative STEM Education

    Science.gov (United States)

    Meabh Kelly, Susan; Smith, Walter

    2016-04-01

    Global Collaborative STEM Education, as the name suggests, simultaneously supports two sets of knowledge and skills. The first set is STEM -- science, technology, engineering and math. The other set of content knowledge and skills is that of global collaboration. Successful global partnerships require awareness of one's own culture, the biases embedded within that culture, as well as developing awareness of the collaborators' culture. Workforce skills fostered include open-mindedness, perseverance when faced with obstacles, and resourceful use of technological "bridges" to facilitate and sustain communication. In respect for the 2016 GIFT Workshop focus, Global Collaborative STEM Education projects dedicated to astronomy research will be presented. The projects represent different benchmarks within the Global Collaborative STEM Education continuum, culminating in an astronomy research experience that fully reflects how the global STEM workforce collaborates. To facilitate wider engagement in Global Collaborative STEM Education, project summaries, classroom resources and contact information for established international collaborative astronomy research projects will be disseminated.

  7. Cultivation of Autonomous Learning Ability of Students Learning College English

    Institute of Scientific and Technical Information of China (English)

    Yang Ruping; Qiu Shifeng

    2014-01-01

    As the mode of college English teaching is gradually transformed from the teacher-centered into the student-centered teaching mode, the cultivation of college English autonomous learning ability has become increasingly important. This paper, starting from the theory of autonomous learning, makes an analysis of current situation of college English teaching and points out the necessity of this ability-cultivation for English learning. In the end, it puts forward several strategies of cultivating the ability of college English autonomous learning.

  8. Soil covering in organic cultivation of onion cultivars

    OpenAIRE

    Leonardo Barreto Tavella; Regina Lúcia Felix Ferreira; Sebastião Elviro de Araújo Neto; Antônio Jussie da Silva Solino; Eliana Mara Napoli Corrêa de Paula da Silva; Maísa Pinto Bravin

    2015-01-01

    The soil preparation in horticulture, including organic, is characterized by intense soil tillage, which increases energy costs and unbalanced the environment. The organic system in onion cultivation has shown satisfactory results, however the soil covering use tends to improve the cultivation environment and may result in higher yields. The objective of this work was to evaluate the performance of onion cultivars in organic cultivation under different soil coverages. The experiment was co...

  9. STEM CELLS AND PROTEOMICS

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yong-ming; GUO Tian-nan; HUANG Shi-ang

    2006-01-01

    The distinctive features of proteomics are large-scale and high throughput. The key techniques of proteomics are two-dimensional gel electrophoresis, mass spectrometry and bioinformatics. Stem cell can differentiate into all kinds of cells, tissues and organs. There are many proteins and cytokines involved in the process of differentiation. Applying proteomics techniques to the research of the complex process of stem cell differentiation is of great importance to study the mechanism and applications of stem cell differentiation.

  10. Improving the shallot and hot pepper cultivation system in the coastal plain of Northern Java

    OpenAIRE

    Putter, de, H.; Witono, A.

    2013-01-01

    This report aims to improve cultivation and to enhance farmers' income in the Brebes region of Northern Java. First, a brief description of vegetable cultivation in the Brebes region is given. Also profits of vegetable cultivation are discussed and bottlenecks in the current cultivation system. In shallot and hot pepper cultivation a main constraint is the alternating change in land use. With rice cultivation the land is levelled and flooded and with vegetable cultivation raised beds are made...

  11. Recent progress in microbial cultivation techniques.

    Science.gov (United States)

    Park, Enoch Y

    2004-01-01

    Recent advances in the improvement of microbial cultivation are reviewed, with emphasis on biochemical engineering techniques as a means of obtaining high production rate of bioproduct. Possible uses of high cell density culture include their use in food industry as well as in the production of new medicines and in biotechnology. Concentration of microorganisms using a hollow fiber membrane or centrifuge, and increase in cell density by controlling the pH, dissolved oxygen, or carbon source concentrations of the culture broth with control algorithms are discussed. In a culture of filamentous microorganisms the mycelial morphology is hard to define and it is difficult to quantify its amount, and this is one of the bottlenecks hampering the improvement of production rate. Specific features of mycelial cultivation in the presence of highly pulpy mycelia and entangled-pellets are scrutinized by visual inspection through a microscope that is linked to a computer, and using software that can characterize the mycelial morphology. Image analysis technology for analyzing the mycelial image captured by a digital camera is a potential tool for morphological analysis, including analysis of the morphological development of filamentous microorganisms.

  12. Exposure of human nasal epithelial cells to formaldehyde does not lead to DNA damage in lymphocytes after co-cultivation.

    Science.gov (United States)

    Neuss, Simone; Moepps, Barbara; Speit, Günter

    2010-07-01

    We performed in vitro co-cultivation experiments with primary human nasal epithelial cells (HNEC) and isolated lymphocytes to investigate whether reactive formaldehyde (FA) can be passed on from nasal epithelial cells (site of first contact) to lymphocytes located in close proximity and induce DNA damage in these cells. A modified comet assay was used as a sensitive method for the detection of FA-induced DNA-protein cross links (DPX) because DPX are the most relevant type of FA-induced DNA damage. Our results clearly indicate that co-cultivation of lymphocytes with HNEC exposed to FA for 1 h causes a concentration-related induction of DPX in lymphocytes when co-cultivation takes place in the exposure medium. However, when the exposure medium is changed after FA treatment of HNEC and before lymphocytes are added, no induction of DPX is measured in lymphocytes even after exposure of HNEC to high FA concentrations (300 microM) and extended co-cultivation (4 h). Direct measurement of FA in the cell culture medium by a sensitive fluorescent detection kit indicated that FA is actually not released even from highly exposed cells into the cell culture medium. These results suggest that FA that has entered nasal epithelial cells is not released and does not damage other cells in close proximity to the epithelial cells. If these results also apply to the in vivo situation, FA would only be genotoxic towards directly exposed cells (site of first contact) and there should be no significant delivery of inhaled FA to other cells and distant sites. Our results do not support a recently proposed hypothetic mechanism for FA-induced leukaemia by damaging circulating haematopoietic stem cells or haematopoietic progenitor cells in nasal passages, which then travel to the bone marrow and become initiated leukaemic stem cells.

  13. Cancer stem cell metabolism

    National Research Council Canada - National Science Library

    Peiris-Pagès, Maria; Martinez-Outschoorn, Ubaldo E; Pestell, Richard G; Sotgia, Federica; Lisanti, Michael P

    2016-01-01

    .... Cancer stem cells also seem to adapt their metabolism to microenvironmental changes by conveniently shifting energy production from one pathway to another, or by acquiring intermediate metabolic phenotypes...

  14. The Effect of Cultivated Wild Ginseng Extract on Preadipocyte Proliferation

    Directory of Open Access Journals (Sweden)

    Byoung-Woo Kim

    2007-12-01

    Full Text Available Objectives : The purpose of this study is to investigate the effects of cultivated wild ginseng extract on primary cultured preadipocyte and adipocytes. Methods : Diminish preadipocyte proliferation does primary role to reduce obesity. So, preadipocytes and adipocytes were performed on cell cultures with using Sprague-Dawley rats and treated with 0.01-1mg/㎖ cultivated wild ginseng extract. Result : At all concentrations, cultivated wild ginseng extract wasn't show the suppress proliferation of preadipocytes significantly and failed to show effects on decomposition of adipocytes except high dosage. Conclusion : Based on these findings, cultivated wild ginseng is not a suitable choice for the treatment of localized obesity.

  15. Cultivation of Intercultural Business Communication Competence in Business English Teaching

    Institute of Scientific and Technical Information of China (English)

    李鹏

    2013-01-01

    Different countries communicate more and more frequently as the development of economic globalization. In business fields, culture becomes into the lever and lubricant influencing those business activities. Thus, cultivating talents with intercultural communication competence is the final purpose of business English teaching. This paper has analyzed the reasons for the lacking of cultivating of intercultural communication competence in business English teaching by using the theories like the relationship between culture and language and communication competence, and then it suggested some ways to cultivate such kind of competence. In these ways, it is hoped that will cultivate more talents with excellent quality of intercultural communication competence and suitable for this age of economic globalization.

  16. Domestication of a Mesoamerican cultivated fruit tree, Spondias purpurea.

    Science.gov (United States)

    Miller, Allison; Schaal, Barbara

    2005-09-01

    Contemporary patterns of genetic variation in crops reflect historical processes associated with domestication, such as the geographic origin(s) of cultivated populations. Although significant progress has been made in identifying several global centers of domestication, few studies have addressed the issue of multiple origins of cultivated plant populations from different geographic regions within a domestication center. This study investigates the domestication history of jocote (Spondias purpurea), a Mesoamerican cultivated fruit tree. Sequences of the chloroplast spacer trnG-trnS were obtained for cultivated and wild S. purpurea trees, two sympatric taxa (Spondias mombin var. mombin and Spondias radlkoferi), and two outgroups (S. mombin var. globosa and Spondias testudinus). A phylogeographic approach was used and statistically significant associations of clades and geographical location were tested with a nested clade analysis. The sequences confirm that wild populations of S. purpurea are the likely progenitors of cultivated jocote trees. This study provides phylogeographic evidence of multiple domestications of this Mesoamerican cultivated fruit tree. Haplotypes detected in S. purpurea trees form two clusters, each of which includes alleles recovered in both cultivated and wild populations from distinct geographic regions. Cultivated S. purpurea populations have fewer unique trnG-trnS alleles than wild populations; however, five haplotypes were absent in the wild. The presence of unique alleles in cultivation may reflect contemporary extinction of the tropical dry forests of Mesoamerica. These data indicate that some agricultural habitats may be functioning as reservoirs of genetic variation in S. purpurea.

  17. [Arbuscular mycorrhiza of cultivated and wild Pinellia ternata].

    Science.gov (United States)

    Cheng, Litao; Guo, Qiaosheng; Liu, Zuoyi

    2010-02-01

    To study the arbuscular mycorrhiza and arbuscular mycorrhizal fungi associated with cultivated and wild Pinellia ternata in Guizhou province. Wild and cultivated P. ternata roots were observed through staining and microscopic examination, the arbuscular mycorrhizal fungi spores were isolated through wet thieving according to Gerdemann & Nicolson (1963), the spores were identified following the description of Schenck & Pérez (1988), and some previous publications. The typical arbuscular mycorrhiza (AM) structure was showed according to a research of wild and cultivated P. ternata. In the survey of AM fungi species in the rhizosphere of wild and cultivated P. ternata, 3 genera and 21 species were found, 3 genera and 7 species were identified. 5 species of them belong to Glomus, 1 species belongs to Scutellospora, 1 species belongs to Gigaspora, including Glomus mosseae, G. intraradices, G. melanosporum, G. deserticola, G. aggregatum, Scutellospora castanea, Gigaspora albida, and one of them was a new record, i.e., Scutellospora castanea which was the dominant species in Bijie. The diversity of AM fungi between wild and cultivated Pinellia ternata was showed on this survey, the fungi associated with wild ones are different form the cultivated ones, such as Gigaspora albida only occurs in cultivated ones, Glomus melanosporum only occurs in wild ones, while Glomus mosseae and Glomus intraradices occur in both wild and cultivated ones, and there were specialization species in Bijie, all these can provide new though for solving degradation problem of cultivated Pinellia ternata.

  18. Cultivation of native seaweed Gracilaria domingensis (Rhodophyta in Southern Brazil

    Directory of Open Access Journals (Sweden)

    José Pedrassoli Salles

    2010-06-01

    Full Text Available The aim of this work was to study the cultivation of Gracilaria domingensis in a mussel farming urbanized area in Santa Catarina, Brazil. Relative growth rate was the parameter used to evaluate the cuttings attachment methods on the cultivation rope, cuttings density, cultivation period and cystocarpic versus unfertile thalli performance. The cultivation was feasible only when protected by net cages due to herbivory. The tie-tie attachment method presented the best results. No differences were observed when comparing the cuttings densities and reproductive phase. Future studies should evaluate the cost-effectiveness of producing the species in net cages and its potential as biofilter.

  19. Modern Methods for Isolation, Purification, and Cultivation of Soil Cyanobacteria.

    Science.gov (United States)

    Temraleeva, A D; Dronova, S A; Moskalenko, S V; Didovich, S V

    2016-07-01

    Up-to-date methods for isolation of cyanobacteria from soil samples, removal of accompanying microflora, obtaining axenic strains, and -conditions and media for subsequnt cultivation are reviewed. Char acterization of soil as a specific habitat for cyanobacteria is provided. Comparative analysis of pH and ele- mental composition of the liquid phase of most soil types with the media for cultivating cyanobacteria is car- ried out. The functional role of the major components required for the cultivation of cyanobacteria is de- scribed. The problems associated with isolation, purification, and cultivation of soil cyanobacteria, as well as the relevant solutions, are discussed.

  20. Mesenchymal stem cell ingrowth and differentiation on coralline hydroxyapatite scaffolds.

    Science.gov (United States)

    Mygind, Tina; Stiehler, Maik; Baatrup, Anette; Li, Haisheng; Zou, Xuenong; Flyvbjerg, Allan; Kassem, Moustapha; Bünger, Cody

    2007-02-01

    Culture of osteogenic cells on a porous scaffold could offer a new solution to bone grafting using autologous human mesenchymal stem cells (hMSC) from the patient. We compared coralline hydroxyapatite scaffolds with pore sizes of 200 and 500 microm for expansion and differentiation of hMSCs. We cultivated the hMSC statically or in spinner flasks for 1, 7, 14 and 21 days and found that the 200-microm pore scaffolds exhibited a faster rate of osteogenic differentiation than did the 500-microm pore scaffolds as shown by an alkaline phosphatase activity assay and real-time reverse transcriptase polymerase chain reaction for 10 osteogenic markers. The 500-microm scaffolds had increased proliferation rates and accommodated a higher number of cells (shown by DNA content, scanning electron microscopy and fluorescence microscopy). Thus the porosity of a 3D microporous biomaterial may be used to steer hMSC in a particular direction. We found that dynamic spinner flask cultivation of hMSC/scaffold constructs resulted in increased proliferation, differentiation and distribution of cells in scaffolds. Therefore, spinner flask cultivation is an easy-to-use inexpensive system for cultivating hMSCs on small to intermediate size 3D scaffolds.

  1. Corneal surface reconstruction - a short review

    Directory of Open Access Journals (Sweden)

    Madhavan H N

    2009-01-01

    . Cells or tissues can be embedded in a liquid Mebiol gel solution at lower than 20°C and cultured three dimensionally in a hydrogel state at 37°C. The sol-gel transition temperature can be controlled by altering chemical composition of thermo-reversible gelation polymer (TGP. Mebiol Gel prevents the growth of the fibroblasts and it is not toxic to cells. In our earlier study, continuous culture cell lines 18 and we demonstrated that Mebiol Gel supported the growth of corneal limbal epithelial cells and these cells expressed both limbal and corneal phenotype, suggesting that limbal epithelial cells cultivated in Mebiol Gel would be a promising material for corneal surface tissue engineering. With this in view, we developed a novel method of cultivation of human limbal cells in a synthetic scaffold made of a thermo reversible polymer, that allows the limbal epithelial cells to survive, proliferate and differentiate into corneal epithelial cells and demonstrated the effectiveness of this polymer for corneal tissue engineering using an experimentally induced limbal deficiency in a rabbit model. In this report, the detailed procedure of the animal model and the results are discussed. We evaluated the efficacy of autologous expanded corneal epithelial cell transplants derived from harvested limbal biopsy cultured on a thermo-reversible polymer (Mebiol Gel for the management of unilateral limbal stem cell disease (LSCD.Corneal limbal biopsies from 12 rabbits were cultured on Mebiol Gel at 37°C. Cells were harvested from the dishes after 3 weeks by reducing temperature to 4°C. Autologous transplantation was undertaken to reconstruct the experimentally induced limbal stem cell deficiency in the rabbit eyes. The corneas of both eyes of all rabbits were harvested later for histological and RT-PCR studies. Reparative surgery was a total success in 7 (58.3%; score, 8-10, partial success in 2 (16.7%; score, 6-7 and failure in 3 (25%; score, <5. Histological and RT-PCR study

  2. Stem Cell Transplants (For Teens)

    Science.gov (United States)

    ... Can I Help Someone Who's Being Bullied? Volunteering Stem Cell Transplants KidsHealth > For Teens > Stem Cell Transplants Print ... Does it Take to Recover? Coping What Are Stem Cells? As you probably remember from biology class, every ...

  3. The Cultivation of Wisdom in the Classroom

    Directory of Open Access Journals (Sweden)

    Juliane Reams

    2015-03-01

    Full Text Available This article focuses on a research project that was designed to inquire into the cultivation of wisdom in the classroom in the context of a newly implemented school subject called Glück (English: happiness. Glück was introduced in order to make a difference in traditional mainstream schooling as a reaction to school curricula that emphasize data and knowledge transfer. It is different and new because it embraces the kind of learning that includes the senses, the mind, body, spirit and the guts. Its multidimensional approach makes an attempt to validate a renunciation of the reductionistic perspective of traditional and contemporary schooling. How it is implemented served as a transformational process through a set of experiential exercises, group discussions, contemplative practices, teamwork etc. It is my aim to give an insight into what I understood as an alternative learning arena embedded in a traditional schooling system and the implications for further development beyond the transfer of data and information in adolescents. Zooming in on Glück, I aim to provide some perspectives on how key experiences and the reflection upon them can lead to the cultivation of wisdom. The understanding of cultivating wisdom I have gained from this study is that it is a dynamic process where the creation of new structures of meaning making emerge through the interaction with others, with oneself and the reflection upon one’s own interior processes that can help unfold, know how to use and refine tacit knowledge. Part of this process is actively discovering and transforming complex information in order to embody it and make it one’s own. Due to the assumption that traditional schooling mostly puts an emphasis on conveying informational knowledge (Hart, 2009; Sternberg, 2001 (to the more or less attentive students and another assumption that wisdom is often seen in connection to age, this article makes an attempt to give an alternative perspective. In

  4. Constructing skin-equivalents using hair follicle stem cells

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective: To establish the method of constructing skin-equivalents (SE) using hair follicle stem cells(HFSC).Methods: K19 positive cells derived from hair were cultivated using serum-free medium KGM and seeded on dermal equivalents (DE).After the culture between the air-liquid interface for 14 days, SE were harvested and used for evaluation. Results: K19 positive cells chosen as HFSC were located in bulge of out root sheet in hair follicle. Cultivated HFSC could build a fully developed, multi-layered epidermis on the basis of DE, resembling the skin structure. Conclusion: HFSC located in out root sheet can differentiate into keratinocyte in vitro and be used for SE construction.

  5. Vernalization response of Phleum pratense and its relationships to stem lignification and floral transition

    DEFF Research Database (Denmark)

    Seppänen, Mervi M; Pakarinen, Kirsi; Jokela, Venla

    2010-01-01

    Background Timothy is a long-day grass species well adapted for cultivation in northern latitudes. It produces elongating tillers not only in spring growth but also later in summer. As the quantity and quality of harvested biomass is dictated by canopy architecture and the proportion of stem-form...

  6. Investigating Preservice STEM Teacher Conceptions of STEM Education

    Science.gov (United States)

    Radloff, Jeff; Guzey, Selcen

    2016-10-01

    Surrounding the national emphasis on improving STEM education, effective STEM educators are required. Connected, yet often overlooked, is the need for effective preservice STEM teaching instruction for incoming educators. At a basic level, preservice STEM teacher education should include STEM content, pedagogy, and conceptualization. However, the literature suggests no leading conception of STEM education, and little is known about how preservice STEM teachers are conceptualizing STEM education. In order to explore preservice STEM teacher conceptions of STEM education, preservice teachers at a large, Midwestern research university were given an open-ended survey eliciting both textual and visual responses. Here, we report and discuss the results of employing this instrument in relation with the current STEM conceptualization literature.

  7. Immunology of Stem Cells and Cancer Stem Cells

    Institute of Scientific and Technical Information of China (English)

    Xiao-Feng Yang

    2007-01-01

    The capacity of pluri-potent stem cells to repair the tissues in which stem cells reside holds great promise in development of novel cell replacement therapeutics for treating chronic and degenerative diseases. However,numerous reports show that stem cell therapy, even in an autologous setting, triggers lymphocyte infiltration and inflammation. Therefore, an important question to be answered is how the host immune system responds to engrafted autologous stem cells or allogeneous stem cells. In this brief review, we summarize the progress in several related areas in this field, including some of our data, in four sections: (1) immunogenicity of stem cells; (2)strategies to inhibit immune rejection to allograft stem cells; (3) immune responses to cancer stem cells; and (4)mesenchymal stem cells in immune regulation. Improvement of our understanding on these and other aspects of immune system-stem cell interplay would greatly facilitate the development of stem cell-based therapeutics for regenerative purposes.

  8. Stem cells in urology.

    Science.gov (United States)

    Aboushwareb, Tamer; Atala, Anthony

    2008-11-01

    The shortage of donors for organ transplantation has stimulated research on stem cells as a potential resource for cell-based therapy in all human tissues. Stem cells have been used for regenerative medicine applications in many organ systems, including the genitourinary system. The potential applications for stem cell therapy have, however, been restricted by the ethical issues associated with embryonic stem cell research. Instead, scientists have explored other cell sources, including progenitor and stem cells derived from adult tissues and stem cells derived from the amniotic fluid and placenta. In addition, novel techniques for generating stem cells in the laboratory are being developed. These techniques include somatic cell nuclear transfer, in which the nucleus of an adult somatic cell is placed into an oocyte, and reprogramming of adult cells to induce stem-cell-like behavior. Such techniques are now being used in tissue engineering applications, and some of the most successful experiments have been in the field of urology. Techniques to regenerate bladder tissue have reached the clinic, and exciting progress is being made in other areas, such as regeneration of the kidney and urethra. Cell therapy as a treatment for incontinence and infertility might soon become a reality. Physicians should be optimistic that regenerative medicine and tissue engineering will one day provide mainstream treatment options for urologic disorders.

  9. Making STEM Connections

    Science.gov (United States)

    Stump, Sheryl L.; Bryan, Joel A.; McConnell, Tom J.

    2016-01-01

    Integrated approaches to education in science, technology, engineering, and mathematics (STEM), especially those set in the context of real-world situations, can motivate and deepen students' learning of the STEM subjects (National Academy of Engineering and National Research Council 2014). This article describes two integrated investigations used…

  10. Teaching STEM by Design

    Science.gov (United States)

    Billiar, Kristen; Hubelbank, Jeanne; Oliva, Thomas; Camesano, Terri

    2014-01-01

    Developing innovative science, technology, engineering and mathematics (STEM) curricula that elicit student excitement for learning is a continuous challenge for K-12 STEM teachers. Generating these lessons while meeting conflicting pedagogical objectives and constraints of time, content, and cost from various parties is truly a challenging task…

  11. Stem cells in dermatology.

    Science.gov (United States)

    Ogliari, Karolyn Sassi; Marinowic, Daniel; Brum, Dario Eduardo; Loth, Fabrizio

    2014-01-01

    Preclinical and clinical research have shown that stem cell therapy could be a promising therapeutic option for many diseases in which current medical treatments do not achieve satisfying results or cure. This article describes stem cells sources and their therapeutic applications in dermatology today.

  12. Dazlin' pluripotent stem cells

    NARCIS (Netherlands)

    Welling, M.A.

    2014-01-01

    Pluripotent embryonic stem cells (ESCs) can be isolated from the inner cell mass (ICM) of blastocyst embryos and differentiate into all three germ layers in vitro. However, despite their similar origin, mouse embryonic stem cells represent a more naïve ICM-like pluripotent state whereas human embryo

  13. Aneuploidy in stem cells

    NARCIS (Netherlands)

    Garcia-Martinez, Jorge; Bakker, Bjorn; Schukken, Klaske M; Simon, Judith E; Foijer, Floris

    2016-01-01

    Stem cells hold enormous promise for regenerative medicine as well as for engineering of model systems to study diseases and develop new drugs. The discovery of protocols that allow for generating induced pluripotent stem cells (IPSCs) from somatic cells has brought this promise steps closer to real

  14. USE OF ARTIFICIAL LIGHT IN MUSHROOM CULTIVATION

    Directory of Open Access Journals (Sweden)

    N. L. Poyedinok

    2013-12-01

    Full Text Available Artificial light is used in greenhouses to increase productivity and quality of agricultural and ornamental plants. Despite the awareness of the fact that light also plays important role in the life of nonhotosynthetic organisms, such as fungi, its using in their biotechnology cultivation is currently limited. Science has quite a large amount information about the influence of artificial light of different nature on morphogenesis, metabolic processes and productivity of more than 100 species of fungi, many of which are valuable producers of biologically active compounds. Themechanisms of photoreactions of various fungi, which is an integral part of a purposeful photoregulation their activity in biotechnological processes are described. The analysis of the researches and of the experience of their practical application allows predicting potential of using artificial light in mushroom growing industry, as well as in creating highly productive, environmentally clean technologies of targeted synthesis of the final product.

  15. Cultivating character: the art of living.

    Science.gov (United States)

    Paulson, Steve; Barrett, Lisa Feldman; Kitcher, Philip; Tiberius, Valerie

    2016-11-01

    Nearly everyone agrees that knowledge is gained through diligent study and investigation, but there is far greater ambiguity when it comes to the meaning of wisdom and how it is acquired. What is wisdom, and how can it be attained? Is there an empirical relationship between wisdom and the cultivation of character, as Aristotle and others have argued? Are the development of virtue and the fulfillment of our innate potential prerequisites to living the good life? Steven Paulson, moderator and executive producer of To the Best of our Knowledge, led a discussion with philosopher Philip Kitcher, philosopher Valerie Tiberius, and psychologist Lisa Feldman Barrett on role of wisdom in the interplay between positive emotions, virtues, and character. © 2016 New York Academy of Sciences.

  16. Microalgae: cultivation techniques and wastewater phycoremediation.

    Science.gov (United States)

    Pacheco, Marcondes M; Hoeltz, Michele; Moraes, Maria S A; Schneider, Rosana C S

    2015-01-01

    Generation of liquid and gaseous effluents is associated with almost all anthropogenic activities. The discharge of these effluents into the environment without treatment has reduced the availability and quality of natural resources, representing a serious threat to the balance of different ecosystems and human health. Universal access to water and global warming are topics of intense concern and are listed as priorities in the vast majority of global scientific, social and political guidelines. Conventional techniques to treat liquid and gaseous effluents pose economic and/or environmental limitations that prevent their use in certain applications. The technique of phycoremediation, which uses microalgae, macroalgae, and cyanobacteria for the removal or biotransformation of pollutants, is an emerging technology that has been highlighted due to its economic viability and environmental sustainability. This literature review discusses different techniques of microalgae cultivation and their use in the phycoremediation of contaminants in wastewater.

  17. Breeding and Cultivation Technique of Ditian 6

    Institute of Scientific and Technical Information of China (English)

    Jianbin YAN; Linsheng SHAO; Junhua WANG; Yonggang CHENG; Ruigang WANG; Xu PANG; Haiying LIANG; Xuebiao ZHANG; Peimin ZHANG

    2016-01-01

    Ditian 6 is super sweet corn hybrid. Its parents are inbred line 201-2 and 769 respectively. It was certificated by Variety Certification Committee of Shanxi Province in 2013. Ditian 6 participated in regional trials of Shanxi Province in 2010 and 2011. The average fresh ear yield is 14257. 5 kg / ha. Its growth period is 81 d,belonging to the early variety. It has obvious advantages if it is early cultivated. The kernel is yellow,and the quality reaches a high level. In the early or late market,it has significant economic benefits. The variety has strong resistance to disease and adversity,with wide adaptability,high and stable yield. It can be planted in the areas where accumulated temperature is above 2300℃.

  18. Isolation, cultivation and transfection of human keratinocytes.

    Science.gov (United States)

    Zare, Sona; Zarei, Mohammad Ali; Ghadimi, Tayyeb; Fathi, Fardin; Jalili, Ali; Hakhamaneshi, Mohammad Saeed

    2014-04-01

    Human keratinocytes could be used in the repair of damaged skin, in tissue engineering applications, gene therapy and recently, the generation of iPS cells. We isolated human keratinocytes from foreskin and subsequently cultured them on fibronectin, collagen type I, gelatin and laminin-coated dishes that contained three different types of serum-free medium (epilife, KSM or CnT). We developed improved conditions for efficient transfection of these human keratinocytes by testing three common transfection methods and a GFP plasmid vector. The isolated cells showed typical keratinocyte morphology and expressed the epithelial cell specific antigen, cytokeratin 14. Collagen type 1, epilife medium and lipofectamin 2000 gave the best results for isolation and transfection of human keratinocytes. Our protocol can be used as a reproducible, simple and efficient method for isolation, cultivation and genetic manipulation of human keratinocytes, which may be useful in cell and gene therapy applications.

  19. A Space Flight Cultivation Protocol for Arabidopsis

    Science.gov (United States)

    Levine, H. G.

    2008-06-01

    A tube-based method is presented for the cultivation and manipulation of Arabidopsis thaliana during space flight experimentation. Seeds were germinated on rock-wool plugs and subsequently transferred into modified polypropylene conical tubes (cut to 5 cm lengths) at 7 days after planting. Each tube contained four side-situated slits through which capillary mat strips were woven. An additional capillary mat wick extended from below the tube up through the bottom to the mid-interior portion. The incorporation of Fibrous Ion Exchange Resin Substrate provided nutrients. The tubes were transferred to plant compartments containing a horticulture foam matrix that received water inputs. Vigorous seedling development through to seed production was achieved. Dispersed seeds frequently germinated on top of the foam substrate, yielding a 2nd generation of seedlings. The methods used herein could be applied to other plant species to be flown in space.

  20. Expanding STEM Education | Poster

    Science.gov (United States)

    Editor’s note: This article is written as a reflection on experiential STEM education by a student who completed her Werner H. Kirsten internship in June 2015. Here, she advocates for incorporating hands-on experience into STEM curricula. If the only way for high school students to learn science, technology, engineering, and mathematics (STEM) is through textbooks, then count me out. But how then do you get students to learn STEM outside of the classroom? The focus of this article is to advocate for high school STEM education through experiential learning. Tom Freston, one of the founders and the chief executive officer (CEO) of MTV Productions, said in an interview in Men’s Journal that “innovation is taking two things that already exist and...

  1. Words as cultivators of others minds

    Directory of Open Access Journals (Sweden)

    Theresa S S Schilhab

    2015-11-01

    Full Text Available The embodied-grounded view of cognition and language holds that sensorimotor experiences in the form of ‘re-enactments’ or ‘simulations’ are significant to the individual’s development of concepts and competent language use. However, a typical objection to the explanatory force of this view is that, in everyday life, we engage in linguistic exchanges about much more than might be directly accessible to our senses. For instance, when knowledge-sharing occurs as part of deep conversations between a teacher and student, language is the salient tool by which to obtain understanding, through the unfolding of explanations. Here, the acquisition of knowledge is realised through language, and the constitution of knowledge seems entirely linguistic.In this paper, based on a review of selected studies within contemporary embodied cognitive science, I propose that such linguistic exchanges, though occurring independently of direct experience, are in fact disguised forms of embodied cognition, leading to the reconciliation of the opposing views. I suggest that, in conversation, interlocutors use Words as Cultivators (WAC of other minds as a direct result of their embodied-grounded origin, rendering WAC a radical interpretation of the Words as social Tools (WAT proposal. The WAC hypothesis endorses the view of language as dynamic, continuously integrating with, and negotiating, cognitive processes in the individual. One such dynamic feature results from the ‘linguification process’, a term by which I refer to the socially produced mapping of a word to its referent which, mediated by the interlocutor, turns words into cultivators of others minds. In support of the linguification process hypothesis and WAC, I review relevant embodied-grounded research, and selected studies of instructed fear conditioning and guided imagery.

  2. High-power LEDs for plant cultivation

    Science.gov (United States)

    Tamulaitis, Gintautas; Duchovskis, Pavelas; Bliznikas, Zenius; Breive, Kestutis; Ulinskaite, Raimonda; Brazaityte, Ausra; Novickovas, Algirdas; Zukauskas, Arturas; Shur, Michael S.

    2004-10-01

    We report on high-power solid-state lighting facility for cultivation of greenhouse vegetables and on the results of the study of control of photosynthetic activity and growth morphology of radish and lettuce imposed by variation of the spectral composition of illumination. Experimental lighting modules (useful area of 0.22 m2) were designed based on 4 types of high-power light-emitting diodes (LEDs) with emission peaked in red at the wavelengths of 660 nm and 640 nm (predominantly absorbed by chlorophyll a and b for photosynthesis, respectively), in blue at 455 nm (phototropic function), and in far-red at 735 nm (important for photomorphology). Morphological characteristics, chlorophyll and phytohormone concentrations in radish and lettuce grown in phytotron chambers under lighting with different spectral composition of the LED-based illuminator and under illumination by high pressure sodium lamps with an equivalent photosynthetic photon flux density were compared. A well-balanced solid-state lighting was found to enhance production of green mass and to ensure healthy morphogenesis of plants compared to those grown using conventional lighting. We observed that the plant morphology and concentrations of morphologically active phytohormones is strongly affected by the spectral composition of light in the red region. Commercial application of the LED-based illumination for large-scale plant cultivation is discussed. This technology is favorable from the point of view of energy consumption, controllable growth, and food safety but is hindered by high cost of the LEDs. Large scale manufacturing of high-power red AlInGaP-based LEDs emitting at 650 nm and a further decrease of the photon price for the LEDs emitting in the vicinity of the absorption peak of chlorophylls have to be achieved to promote horticulture applications.

  3. Sheep manure vermicompost supplemented with a native diazotrophic bacteria and mycorrhizas for maize cultivation.

    Science.gov (United States)

    Gutiérrez-Miceli, F A; Moguel-Zamudio, B; Abud-Archila, M; Gutiérrez-Oliva, V F; Dendooven, L

    2008-10-01

    An orthogonal experimental design L9 (3(4)) with 10 repetitions was used to investigate the effect of Glomus claroideum (0, 1 or 2g(-1) plant), G. fasciculatum (0, 1 or 2g plant(-1)), native diazotrophic bacteria (0, 10(3) and 10(5) UFC ml(-1)) and sheep manure vermicompost (0%, 5% and 10% v/v) on maize plant growth, N and P in leaves and mycorrhization percent. Vermicompost explained most of the variation found for leaf number, wet weight, stem height, and diameter. Both mycorrhizas increased the plant wet weight but G. fasciculatum the most. Mycorrhization increased the P content, but not the N content. Mycorrhizal colonization increased when diazotrophic bacteria and vermicompost were added. It was found that weight of maize plants cultivated in peat moss amended with vermicompost increased when supplemented with G. fasciculatum and diazotrophic bacteria.

  4. Environmental life cycle assessment of Ethiopian rose cultivation

    NARCIS (Netherlands)

    Sahle, A.H.; Potting, J.

    2013-01-01

    A life cycle assessment (LCA) was conducted for Ethiopian rose cultivation. The LCA covered the cradle-togate production of all inputs to Ethiopian rose cultivation up to, and including transport to the Ethiopian airport. Primary data were collected about materials and resources used as inputs to, a

  5. Awareness of Cultural Differences and Cultivation of Intercultural Communicative Competence

    Institute of Scientific and Technical Information of China (English)

    肖攀

    2014-01-01

    <正>Ⅰ.Introduction The aim of foreign language teaching is not only to make students get familiar with the knowledge of Western countries,but also to cultivate the students’competence in intercultural communication,this paper will list some cultural differences between China and Western counrties,then present some personal opinions on how to cultivate students’competence in

  6. Micrometeorological principles of protected cultivation for fruit crops

    Science.gov (United States)

    Protected cultivation is a broad term commonly used among producers of specialty crops. Techniques can range from complex fixed structures to field site selection, to straightforward cultural practices in the field. This introduction to the ASHS workshop "Protected cultivation for fruit crops" consi...

  7. Moral Self-Cultivation East and West: A Critique

    Science.gov (United States)

    Slote, Michael

    2016-01-01

    Moral Self-Cultivation plays an important, even a central role, in the Confucian philosophical tradition, but philosophers in the West, most notably Aristotle and Kant, also hold that moral self-cultivation or self-shaping is possible and morally imperative. This paper argues that these traditions are psychologically unrealistic in what they say…

  8. Cultivating Discontinuity: Pentecostal Pedagogies of Yielding and Control

    Science.gov (United States)

    Brahinsky, Josh

    2013-01-01

    Exploring missionary study at an Assemblies of God Bible college through ethnography and training manuals demonstrates systematic pedagogies that cultivate sensory capabilities encouraging yielding, opening to rupture, and constraint. Ritual theory and the Anthropology of Christianity shift analytic scales to include "cultivation," a…

  9. Adolescents and Ambivalence toward Marriage: A Cultivation Analysis.

    Science.gov (United States)

    Signorielli, Nancy

    1991-01-01

    Using cultivation theory, the portrayal of marriage on prime-time television was examined, and the relationship between television viewing and ambivalence about marriage and family was explored for over 3,200 high school seniors. It was evident that television may cultivate important ideas about marriage, interpersonal relationships, and family.…

  10. Examining Cultivation from a Psychological Perspective: Component Subprocesses.

    Science.gov (United States)

    Potter, W. James

    1991-01-01

    Attempts to elaborate the cultivation hypothesis by examining some proposed subprocesses, especially learning and construction with first- and second-order measures. Examines the relationship between first- and second-order measures. Argues that cultivation theory needs to be extended. (SR)

  11. Environmental life cycle assessment of Ethiopian rose cultivation

    NARCIS (Netherlands)

    Sahle, A.H.; Potting, J.

    2013-01-01

    A life cycle assessment (LCA) was conducted for Ethiopian rose cultivation. The LCA covered the cradle-togate production of all inputs to Ethiopian rose cultivation up to, and including transport to the Ethiopian airport. Primary data were collected about materials and resources used as inputs to,

  12. Towards Personalized Regenerative Cell Therapy: Mesenchymal Stem Cells Derived from Human Induced Pluripotent Stem Cells.

    Science.gov (United States)

    Lin, Lin; Bolund, Lars; Luo, Yonglun

    2016-01-01

    Mesenchymal stem cells (MSCs) are adult stem cells with the capacity of self-renewal and multilineage differentiation, and can be isolated from several adult tissues. However, isolating MSCs from adult tissues for cell therapy is hampered by the invasive procedure, the rarity of the cells and their attenuated proliferation capacity when cultivated and expanded in vitro. Human MSCs derived from induced pluripotent stem cells (iPSC-MSCs) have now evolved as a promising alternative cell source for MSCs and regenerative medicine. Several groups, including ours, have reported successful derivation of functional iPSC-MSCs and applied these cells in MSC-based therapeutic testing. Still, the current experience and understanding of iPSC-MSCs with respect to production methods, safety and efficacy are primitive. In this review, we highlight the methodological progress in iPSC-MSC research, describing the importance of choosing the right sources of iPSCs, iPSC reprogramming methods, iPSC culture systems, embryoid body intermediates, pathway inhibitors, basal medium, serum, growth factors and culture surface coating. We also highlight some progress in the application of iPSC-MSCs in direct cell therapy, tissue engineering and gene therapy.

  13. The Cultivation of Cultural Awareness in English Teaching

    Institute of Scientific and Technical Information of China (English)

    王宁

    2015-01-01

    As the development of the information age,the cultivation of intercultural communicative competence has been extremely important. Thus foreign language teaching lays stress on the cultivation of language comprehensive application ability. Culture awareness is an important part of language comprehensive application ability. The cultivating of students’ cultural awareness is beneficial to improve their humanistic quality,broaden their international view,strengthen their patriotism spirit and sense of national mission,and achieve their all-round development. The paper will discuss the current situation of cultural awareness cultivation in English teaching. In view of the problems and its causes existing in the cultural awareness cultivation,three count measures have been proposed.

  14. Functional State Modelling of Cultivation Processes: Dissolved Oxygen Limitation State

    Directory of Open Access Journals (Sweden)

    Olympia Roeva

    2015-04-01

    Full Text Available A new functional state, namely dissolved oxygen limitation state for both bacteria Escherichia coli and yeast Saccharomyces cerevisiae fed-batch cultivation processes is presented in this study. Functional state modelling approach is applied to cultivation processes in order to overcome the main disadvantages of using global process model, namely complex model structure and a big number of model parameters. Alongwith the newly introduced dissolved oxygen limitation state, second acetate production state and first acetate production state are recognized during the fed-batch cultivation of E. coli, while mixed oxidative state and first ethanol production state are recognized during the fed-batch cultivation of S. cerevisiae. For all mentioned above functional states both structural and parameter identification is here performed based on experimental data of E. coli and S. cerevisiae fed-batch cultivations.

  15. Protein hydrolysate as a component of salinized soil in the cultivation of Ageratum houstonianum Mill. (Asteraceae

    Directory of Open Access Journals (Sweden)

    Renata Matraszek

    2015-10-01

    Full Text Available The aim of the present study was to evaluate the possibility of using a protein hydrolysate, Hemozym N-K 4.5-6, as a component of salinized soil in the cultivation of flossflower (Ageratum houstonianum Mill., Asteraceae. The experiment was focused on the yield and decorative value of A. houstonianum, grown under different concentrations of NaCl and/or Hemozym. Ageratum houstonianum plants were grown in the soil under different NaCl salinity (EC: 0.28 – as control or 3.25 dS m−1 – salt stress or/and Hemozym dose (0, 0.07 or 0.14 ml kg−1. The results of the experiment imply that A. houstonianum is sensitive to salinity. The application of Hemozym to both unsalinized and salinized soils caused an increase in the yield of the plant organs (roots, stems, leaves, and inflorescence, the number of leaves, and the chlorophyll content without significant changes in the carotenoids. Moreover, an increase in the number and size of first-order inflorescences (heads as well as more intensive flower color were observed. Thus, it can be stated that the protein hydrolysate studied can be a beneficial component of both salinized and unsalinized soils in the cultivation of A. houstonianum.

  16. [On plant stem cells and animal stem cells].

    Science.gov (United States)

    You, Yun; Jiang, Chao; Huang, Lu-Qi

    2014-01-01

    A comparison of plant and animal stem cells can highlight core aspects of stem-cell biology. In both kingdoms, stem cells are defined by their clonogenic properties and are maintained by intercellular signals. The signaling molecules are different in plants and animals stem cell niches, but the roles of argonaute and polycomb group proteins suggest that there are some molecular similarities.

  17. Assessing the harms of cannabis cultivation in Belgium.

    Science.gov (United States)

    Paoli, Letizia; Decorte, Tom; Kersten, Loes

    2015-03-01

    Since the 1990s, a shift from the importation of foreign cannabis to domestic cultivation has taken place in Belgium, as it has in many other countries. This shift has prompted Belgian policy-making bodies to prioritize the repression of cannabis cultivation. Against this background, the article aims to systematically map and assess for the first time ever the harms associated with cannabis cultivation, covering the whole spectrum of growers. This study is based on a web survey primarily targeting small-scale growers (N=1293) and on three interconnected sets of qualitative data on large-scale growers and traffickers (34 closed criminal proceedings, interviews with 32 criminal justice experts, and with 17 large-scale cannabis growers and three traffickers). The study relied on Greenfield and Paoli's (2013) harm assessment framework to identify the harms associated with cannabis cultivation and to assess the incidence, severity and causes of such harms. Cannabis cultivation has become endemic in Belgium. Despite that, it generates, for Belgium, limited harms of medium-low or medium priority. Large-scale growers tend to produce more harms than the small-scale ones. Virtually all the harms associated with cannabis cultivation are the result of the current criminalizing policies. Given the spread of cannabis cultivation and Belgium's position in Europe, reducing the supply of cannabis does not appear to be a realistic policy objective. Given the limited harms generated, there is scarce scientific justification to prioritize cannabis cultivation in Belgian law enforcement strategies. As most harms are generated by large-scale growers, it is this category of cultivator, if any, which should be the focus of law enforcement repression. Given the policy origin of most harms, policy-makers should seek to develop policies likely to reduce such harms. At the same time, further research is needed to comparatively assess the harms associated with cannabis cultivation (and

  18. Isolation, cultivation and characterization of CD133+ stem cells from human glioblastoma

    Directory of Open Access Journals (Sweden)

    Lorena Favaro Pavon

    2012-06-01

    Full Text Available Objective: To establish the method of isolation and culture ofhuman glioblastoma neurospheres, and the purification of theirstem cells, followed by the process of obtaining tumor subspheres,immunophenotypically characterizing this clonogenic set. Methods:Through the processing of glioblastoma samples (n=3, the followingstrategy of action was adopted: (i establish primary culture ofglioblastoma; (ii isolation and culture of tumor neurospheres; (iiipurify cells that initiate tumors (CD133+ by magnetic separationsystem (MACS; (iv obtain tumor subspheres; (v study theexpression of the markers nestin, CD133, and GFAP. Results: Thestudy successfully described the process of isolation and culture ofglioblastoma subspheres, which consist of a number of clonogeniccells immunophenotypically characterized as neural, which areable to initiate tumor formation. Conclusion: These findings maycontribute to a better understanding of the process of gliomagenesis.

  19. A study on the comparison of antioxidant effects among cultivated ginseng, and cultivated wild ginseng extracts -Using the measurement of superoxide and hydroxy radical scavenging activities-

    Directory of Open Access Journals (Sweden)

    Tae Jin, Rhim

    2009-06-01

    Full Text Available Objectives : The objective of this study was to compare the antioxidant effects among cultivated wild ginseng and ginseng extracts. Methods : In vitro antioxidant activities were examined by superoxide and hydroxyl radical scavenging activities of ginseng and cultivated wild ginseng extracts. Results : 1. In the superoxide radical scavenging activities of ginseng and cultivated wild ginseng extracts, antioxidant activities of cultivated wild ginseng extracts was showed higher than cultivated ginseng in the concentration of 0.25 and 0.50㎎/㎖. 2. In the hydroxyl radical scavenging activities of ginseng and cultivated wild ginseng extracts, antioxidant activities of cultivated wild ginseng extracts was showed higher than cultivated ginseng in the concentration of 1.0, 2.5, and 5.0㎎/㎖. Conclusions : In summary, the results of this study demonstrate that cultivated wild ginseng extracts had higher antioxidant activities to cultivated ginseng.

  20. Nerve growth factor (NGF)-conjugated electrospun nanostructures with topographical cues for neuronal differentiation of mesenchymal stem cells.

    Science.gov (United States)

    Cho, Young Il; Choi, Ji Suk; Jeong, Seo Young; Yoo, Hyuk Sang

    2010-12-01

    Mesenchymal stem cells (MSCs) were cultivated on the surface of nerve growth factor (NGF)-conjugated aligned nanofibrous meshes for neuronal differentiation. Amine-terminated poly(ethylene glycol) was conjugated to poly(ε-caprolactone) to prepare amine-functionalized block copolymers. The synthesized polymer was electrospun in a rotating drum to prepare aligned nanofibrous meshes. A nerve growth factor was chemically immobilized on the surface-exposed amine groups of the electrospun nanofibrous meshes in the aqueous phase. In vitro release profiles of the nerve growth factor were investigated for NGF-immobilized nanofibrous meshes. The conjugated nerve growth factor was not released for 7 days, while the growth factor physically adsorbed on the nanofibrous meshes showed an initial burst release. MSCs were cultivated on the NGF-conjugated nanofibrous meshes for 5 days, and total RNA was extracted from the cultivated cells. mRNA was extracted from cells for measuring expression levels of neuronal differentiation markers, including nestin, tubulin βIII and map2, in the cultivated stem cells. The conjugation of NGF significantly increased the expression levels of the marker proteins for neuron cells while physically adsorbed NGFs on nanofibrous meshes showed low expression of these marker genes. Furthermore, alignments of nanofibrous meshes clearly increased the expression levels of neuronal makers while the nanofibrous mesh without the topographical cue did not affect neuronal differentiation of the cultivated stem cells. Confocal microscopy revealed that the stem cells on the NGF-conjugated aligned nanofibrous meshes showed intense staining with antibodies against neuronal makers as well as elongated morphology compared to other groups. Thus, the NGF-conjugated nanofibrous meshes with topographical cues significantly increased the neuronal differentiation of mesenchymal stem cells in comparison to NGF-adsorbed nanofibrous meshes.

  1. Fish stem cell cultures.

    Science.gov (United States)

    Hong, Ni; Li, Zhendong; Hong, Yunhan

    2011-04-13

    Stem cells have the potential for self-renewal and differentiation. First stem cell cultures were derived 30 years ago from early developing mouse embryos. These are pluripotent embryonic stem (ES) cells. Efforts towards ES cell derivation have been attempted in other mammalian and non-mammalian species. Work with stem cell culture in fish started 20 years ago. Laboratory fish species, in particular zebrafish and medaka, have been the focus of research towards stem cell cultures. Medaka is the second organism that generated ES cells and the first that gave rise to a spermatogonial stem cell line capable of test-tube sperm production. Most recently, the first haploid stem cells capable of producing whole animals have also been generated from medaka. ES-like cells have been reported also in zebrafish and several marine species. Attempts for germline transmission of ES cell cultures and gene targeting have been reported in zebrafish. Recent years have witnessed the progress in markers and procedures for ES cell characterization. These include the identification of fish homologs/paralogs of mammalian pluripotency genes and parameters for optimal chimera formation. In addition, fish germ cell cultures and transplantation have attracted considerable interest for germline transmission and surrogate production. Haploid ES cell nuclear transfer has proven in medaka the feasibility of semi-cloning as a novel assisted reproductive technology. In this special issue on "Fish Stem Cells and Nuclear Transfer", we will focus our review on medaka to illustrate the current status and perspective of fish stem cells in research and application. We will also mention semi-cloning as a new development to conventional nuclear transfer.

  2. Fish Stem Cell Cultures

    Directory of Open Access Journals (Sweden)

    Ni Hong, Zhendong Li, Yunhan Hong

    2011-01-01

    Full Text Available Stem cells have the potential for self-renewal and differentiation. First stem cell cultures were derived 30 years ago from early developing mouse embryos. These are pluripotent embryonic stem (ES cells. Efforts towards ES cell derivation have been attempted in other mammalian and non-mammalian species. Work with stem cell culture in fish started 20 years ago. Laboratory fish species, in particular zebrafish and medaka, have been the focus of research towards stem cell cultures. Medaka is the second organism that generated ES cells and the first that gave rise to a spermatogonial stem cell line capable of test-tube sperm production. Most recently, the first haploid stem cells capable of producing whole animals have also been generated from medaka. ES-like cells have been reported also in zebrafish and several marine species. Attempts for germline transmission of ES cell cultures and gene targeting have been reported in zebrafish. Recent years have witnessed the progress in markers and procedures for ES cell characterization. These include the identification of fish homologs/paralogs of mammalian pluripotency genes and parameters for optimal chimera formation. In addition, fish germ cell cultures and transplantation have attracted considerable interest for germline transmission and surrogate production. Haploid ES cell nuclear transfer has proven in medaka the feasibility of semi-cloning as a novel assisted reproductive technology. In this special issue on “Fish Stem Cells and Nuclear Transfer”, we will focus our review on medaka to illustrate the current status and perspective of fish stem cells in research and application. We will also mention semi-cloning as a new development to conventional nuclear transfer.

  3. The novel steroidal alkaloids dendrogenin A and B promote proliferation of adult neural stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Khalifa, Shaden A.M., E-mail: shaden.khalifa@ki.se [Department of Neuroscience, Karolinska Institute, Stockholm (Sweden); Medina, Philippe de [Affichem, Toulouse (France); INSERM UMR 1037, Team “Sterol Metabolism and Therapeutic Innovations in Oncology”, Cancer Research Center of Toulouse, F-31052 Toulouse (France); Erlandsson, Anna [Department of Public Health and Caring Sciences, Uppsala University, Uppsala (Sweden); El-Seedi, Hesham R. [Department of Medicinal Chemistry, Biomedical Centre, Uppsala University, Uppsala (Sweden); Silvente-Poirot, Sandrine [INSERM UMR 1037, Team “Sterol Metabolism and Therapeutic Innovations in Oncology”, Cancer Research Center of Toulouse, F-31052 Toulouse (France); University of Toulouse III, Toulouse (France); Institut Claudius Regaud, Toulouse (France); Poirot, Marc, E-mail: marc.poirot@inserm.fr [INSERM UMR 1037, Team “Sterol Metabolism and Therapeutic Innovations in Oncology”, Cancer Research Center of Toulouse, F-31052 Toulouse (France); University of Toulouse III, Toulouse (France); Institut Claudius Regaud, Toulouse (France)

    2014-04-11

    Highlights: • Dendrogenin A and B are new aminoalkyl oxysterols. • Dendrogenins stimulated neural stem cells proliferation. • Dendrogenins induce neuronal outgrowth from neurospheres. • Dendrogenins provide new therapeutic options for neurodegenerative disorders. - Abstract: Dendrogenin A (DDA) and dendrogenin B (DDB) are new aminoalkyl oxysterols which display re-differentiation of tumor cells of neuronal origin at nanomolar concentrations. We analyzed the influence of dendrogenins on adult mice neural stem cell proliferation, sphere formation and differentiation. DDA and DDB were found to have potent proliferative effects in neural stem cells. Additionally, they induce neuronal outgrowth from neurospheres during in vitro cultivation. Taken together, our results demonstrate a novel role for dendrogenins A and B in neural stem cell proliferation and differentiation which further increases their likely importance to compensate for neuronal cell loss in the brain.

  4. Dental pulp stem cells

    DEFF Research Database (Denmark)

    Ashri, N. Y.; Ajlan, S. A.; Aldahmash, Abdullah M.

    2015-01-01

    Inflammatory periodontal disease is a major cause of loss of tooth-supporting structures. Novel approaches for regeneration of periodontal apparatus is an area of intensive research. Periodontal tissue engineering implies the use of appropriate regenerative cells, delivered through a suitable...... scaffold, and guided through signaling molecules. Dental pulp stem cells have been used in an increasing number of studies in dental tissue engineering. Those cells show mesenchymal (stromal) stem cell-like properties including self-renewal and multilineage differentiation potentials, aside from...... an updated review on dental pulp stem cells and their applications in periodontal regeneration, in combination with different scaffolds and growth factors....

  5. Cardiac stem cell niches

    Directory of Open Access Journals (Sweden)

    Annarosa Leri

    2014-11-01

    Full Text Available The critical role that stem cell niches have in cardiac homeostasis and myocardial repair following injury is the focus of this review. Cardiac niches represent specialized microdomains where the quiescent and activated state of resident stem cells is regulated. Alterations in niche function with aging and cardiac diseases result in abnormal sites of cardiomyogenesis and inadequate myocyte formation. The relevance of Notch1 signaling, gap-junction formation, HIF-1α and metabolic state in the regulation of stem cell growth and differentiation within the cardiac niches are discussed.

  6. Application of Reduced Corn Cultivation Technology in Agro-Ecosystem of Cazin Municipality

    OpenAIRE

    Mirsad Veladžić; Fatima Muhamedagić; Emdžad Galijašević

    2011-01-01

    Intensive corn cultivation is predominant in current agriculture of the Una-Sana Canton. One of the corn cultivation methods in agro-ecosystem is reduced cultivation. The paper presents the experiment of “Osmak žuti” (eight-row yellow) corn cultivation on two control sites with application of reduced and intensive cultivation in Cazin municipality. The objectives of this research were to examine the possibility of application of reduced corn cultivation; analyze statistical variation elements...

  7. Nanomechanics of human adipose-derived stem cells

    DEFF Research Database (Denmark)

    Jungmann, Pia M; Mehlhorn, Alexander T; Schmal, Hagen

    2012-01-01

    OBJECTIVES: Human adipose-derived stem cells (ASCs) show gene expression of chondrogenic markers after three-dimensional cultivation. However, hypertrophy and osteogenic transdifferentiation are still limiting clinical applications. The aim of this study was to investigate the impact of small...... stem cells by single-cell elasticity measurements using atomic force microscopy. Results were matched with single-cell size measurements (diameter and volume) and quantitative real time-polymerase chain reaction for osteogenic and hypertrophic (alkaline phosphatase [ALP], collagen type X) as well...... a significantly lower deformability than chondrocytes (Young's modulus: 294.4 vs. 225.1 Pa; ANOVA: pstem cell elasticity to chondrocyte values (221.7 Pa). All other chondrogenic differentiated ASCs presented intermediate elasticity (BMP-2 stimulation: 269.1 Pa...

  8. Determination of the material properties of the different cultivator shares

    Directory of Open Access Journals (Sweden)

    Ebubekir ALTUNTAŞ

    2013-06-01

    Full Text Available In this study, chemical analysis, pulling, hardness test results and spectral analysis of the different cultivator shares of cultivator producers in Amasya and Çorum provinces were evaluated and test results were compared with relevant Turkish Standards. For experiments, the cultivator shares were choosen randomly from A,B, C and D cultivator producers and classified. Chemical analysis revealed SAE 1030, C60, C30 tempered stell types and C10 carburizing steel materials respectively for A, B, C and D cultivator shares. Spectral analysis indicated that cultivator were mainly included medium-carbon steels. All cultivar shares failed to meet recommended Rockwell hardness value of 49 HRC. While the highest hardness was observed in A-1 and C-1 narrow shares with 39.1 HRC, the lowest value was seen in D-2 duck-foot share with 72.88 HRB. According to pulling tests, cultivator shares were found to be complying with relevant reference values indicated in standards.

  9. Plant Stem Cells

    National Research Council Canada - National Science Library

    Greb, Thomas; Lohmann, Jan U

    2016-01-01

    .... While the promise of organ regeneration and the end of cancer have captured our imagination, it has gone almost unnoticed that plant stem cells represent the ultimate origin of much of the food we...

  10. Innovation and STEM Schools

    Science.gov (United States)

    Roberts, Julia Link

    2015-01-01

    How do schools with a focus on science, technology, engineering, and mathematics (STEM) fit in with state goals to increase innovation and to boost the economy? This article briefly discusses how educators can encourage creativity and innovation.

  11. Stem Cell Basics

    Science.gov (United States)

    ... why are they important? Stem cells have the remarkable potential to develop into many different cell types ... of Health, U.S. Department of Health and Human Services, 2016 [cited October 9, 2017 ] Available at < //stemcells. ...

  12. Engineering Stem Cell Organoids

    National Research Council Canada - National Science Library

    Yin, Xiaolei; Mead, Benjamin E; Safaee, Helia; Langer, Robert; Karp, Jeffrey M; Levy, Oren

    2016-01-01

    .... Herein, we discuss basic approaches to generate stem cell-based organoids, their advantages and limitations, and how bioengineering strategies can be used to steer the cell composition and their 3D...

  13. Induced pluripotent stem cells

    Institute of Scientific and Technical Information of China (English)

    Siddhartha Bhowmik; LI Yong

    2011-01-01

    Induced pluripotent stem (iPS) cells are a recent development which has brought a promise of great therapeutic values. The previous technique of somatic cell nuclear transfer (SCNT) has been ineffective in humans. Recent discoveries show that human fibroblasts can be reprogrammed by a transient over expression of a small number of genes; they can undergo induced pluripotency. iPS were first produced in 2006. By 2008, work was underway to remove the potential oncogenes from their structure. In 2009, protein iPS (piPS) cells were discovered. Surface markers and reporter genes play an important role in stem cell research. Clinical applications include generation of self renewing stem cells, tissue replacement and many more. Stem cell therapy has the ability to dramatically change the treatment of human diseases.

  14. What are Stem Cells?

    Directory of Open Access Journals (Sweden)

    Ahmadshah Farhat

    2014-05-01

    Full Text Available   Stem cells are undifferentiated self regenerating multi potential cells. There are three types of stem cells categories by the ability to form after cells and correlated with the body’s development process. Totipotent: these stem cells can form an entire organism such as fertilized egg. Ploripotent: ploripotent cells are those that can form any cell in the body but cannot form an entire organism such as developing embryo’s totipotent cells become ploripotent  Multipotent: Multi potent stem cells are those that can only form specific cells in the body such as blood cells based. Based on the sources of stem cells we have three types of these cells: Autologous: Sources of the patient own cells are (Autologous either the cells from patient own body or his or her cord blood. For this type of transplant the physician now usually collects the periphery rather than morrow because the procedure is easier on like a bane morrow harvest it take place outside of an operating room, and the patient does not to be under general unsetting . Allogenic: Sources of stem cells from another donore are primarily relatives (familial allogenic or completely unrelated donors. Xenogenic: In these stem cells from different species are transplanted e .g striatal porcine fetal mesan cephalic (FVM xenotransplants for Parkinson’s disease. On sites of isolation such as embryo, umbilical cord and other body tissues stem cells are named embnyonic, cord blood, and adult stem cells. The scope of results and clinical application of stem cells are such as: Neurodegenerative conditions (MS,ALS, Parkinson’s, Stroke, Ocular disorders- Glaucoma, retinitis Pigmentosa (RP, Auto Immune Conditions (Lupus, MS,R. arthritis, Diabetes, etc, Viral Conditions (Hepatitis C and AIDS, Heart Disease, Adrenal Disorders, Injury(Nerve, Brain, etc, Anti aging (hair, skin, weight control, overall well being/preventive, Emotional disorders, Organ / Tissue Cancers, Blood cancers, Blood diseases

  15. Advanced continuous cultivation methods for systems microbiology.

    Science.gov (United States)

    Adamberg, Kaarel; Valgepea, Kaspar; Vilu, Raivo

    2015-09-01

    Increasing the throughput of systems biology-based experimental characterization of in silico-designed strains has great potential for accelerating the development of cell factories. For this, analysis of metabolism in the steady state is essential as only this enables the unequivocal definition of the physiological state of cells, which is needed for the complete description and in silico reconstruction of their phenotypes. In this review, we show that for a systems microbiology approach, high-resolution characterization of metabolism in the steady state--growth space analysis (GSA)--can be achieved by using advanced continuous cultivation methods termed changestats. In changestats, an environmental parameter is continuously changed at a constant rate within one experiment whilst maintaining cells in the physiological steady state similar to chemostats. This increases the resolution and throughput of GSA compared with chemostats, and, moreover, enables following of the dynamics of metabolism and detection of metabolic switch-points and optimal growth conditions. We also describe the concept, challenge and necessary criteria of the systematic analysis of steady-state metabolism. Finally, we propose that such systematic characterization of the steady-state growth space of cells using changestats has value not only for fundamental studies of metabolism, but also for systems biology-based metabolic engineering of cell factories.

  16. The organic fertilization in the onion cultivation

    Directory of Open Access Journals (Sweden)

    Roberto Llorente Villa

    2016-02-01

    Full Text Available The present work was developed in the UBPC “The Coast”, belonging to the Miscellaneous Crops Enterprise of Campechuela municipality, Granma province, during the period from November to March of the year 2010 – 2011. It was carried out in a reddish brown fersialitic soil, according with the new genetic classification of the soils of Cuba MINAGRI, (2000, with the objective of studying and evaluating the influence of different organic fertilizers in the growth, development and yield in the cultivation of onion, variety Texas Early Grain. For this reason it was necessary to work on blocks with 4 treatments and 4 replies. The treatments applied were: treatment 1 (vermicompost, treatment 2 (cow dung, treatment 3 (cachaça and treatment 4 (control, those were applied in a solid way. The growth variables that were evaluated were number of leaves, height of the plant, equatorial diameter, polar diameter and fresh weight of the bulb. The yield was also evaluated in t.ha-1 per treatment. High yields are achieved with the application of organic fertilizer, among 27 and 30 t.ha-1, this is an alternative for the sustainable production of this product which is highly demanded by the population.

  17. Skeletal (stromal) stem cells

    DEFF Research Database (Denmark)

    Abdallah, Basem M; Kermani, Abbas Jafari; Zaher, Walid

    2015-01-01

    Skeletal (marrow stromal) stem cells (BMSCs) are a group of multipotent cells that reside in the bone marrow stroma and can differentiate into osteoblasts, chondrocytes and adipocytes. Studying signaling pathways that regulate BMSC differentiation into osteoblastic cells is a strategy....../preadipocyte factor 1 (Dlk1/Pref-1), the Wnt co-receptor Lrp5 and intracellular kinases. This article is part of a Special Issue entitled: Stem Cells and Bone....

  18. Changes in shifting cultivation systems on small Pacific islands

    DEFF Research Database (Denmark)

    Mertz, Ole; Birch-Thomsen, Torben; Elberling, Bo;

    2012-01-01

    The limited information on change in shifting cultivation systems of small islands of the Pacific stands in contrast to increasing evidence of this farming system's demise in other parts of the tropics. Here, we assess changes in agricultural activities during the past 40 years of Bellona Island......, Solomon Islands, where shifting cultivation is still maintained in the traditional way. Fallow length has increased despite population growth due to redistribution of the cultivated area, migration-induced extensification and changes in crops. Productivity of the farming system remains high although...

  19. [Theory and practice of bionic cultivation of traditional Chinese medicine].

    Science.gov (United States)

    Liu, Dahui; Huang, Luqi; Guo, Lanping; Shao, Aijuan; Chen, Meilan

    2009-03-01

    The bionic cultivation of medicinal plant is an ecological cultivation pattern, which is adopting ecological engineering and modern agricultural techniques to simulate the natural ecosystem of wild medicinal plant community, and has been given greater attention on the agriculture of traditional Chinese medicine (TCM). It is also the cross subject that combines Chinese traditional medicine, agronomy, horticulture, ecology, agricultural engineering and management. Moreover, it has significant technology advantages of promoting the sustainable utilization of medicinal plant resources, improving the ecological environment and harmonizing man and nature. So it's important to develop the bionic cultivation of TCM.

  20. A CASE OF LIMBAL MALIGNANT MELANOMA

    Directory of Open Access Journals (Sweden)

    Hansa H

    2015-05-01

    Full Text Available Conjunctival malignant melanoma is a rare pigmented tumor occurring during fifth and sixth decade typically involving limbus with high recurrence rate . A 65 yr male presented with complaints of slowly growing dark colored swelling in his left eye since 2 months . No systemic complaints . A black mass was seen on limbus with lobulated appearance . On USG ocular coats were normal . UBM shows 8*5 mm mass . Excision of mass was done and biopsy confirmed diagnosis . Mass excision was supplemented with cryotherapy . Now patient i s cosmetically and visually satisfied .

  1. The influence of cultivation method on the flowering of Salvia horminum L. 'Oxford Blue'

    Directory of Open Access Journals (Sweden)

    Elżbieta Pogroszewska

    2012-12-01

    Full Text Available Salvia horminum L. 'Oxford Blue' was grown from transplants or it was direct seeded. Four sowing dates were applied: 15 March or 30 March - in a greenhouse, in order to obtain transplants, 13 April, 27 April and 11 May - sown directly into the ground. Three plant densities were applied: 25 plants×m2, 16 plants×m2, 12 plants×m2. It was found that Horminum sage can be grown from transplants or direct seeded. The cultivation from transplants is more advantageous due to the earlier flowering of plants, by about two weeks, and a better quality of inflorescences evaluated in terms of their length and size of bracteoles. Direct sowing of Horminum sage at two-week intervals from the 2nd decade of April till the 2nd decade of May ensures that by the end of August mature inflorescence stems are obtained, ready for cutting. A delay in the date of sowing results in the development of significantly shorter inflorescence stems, irrespective of the plant density. Plant density does not affect significantly the length of the period of inflorescence formation and the date of flowering, but a larger spacing is favourable to plants growing big, what results in a larger fresh weight of the above-ground portion. Sage grown from transplants responses to favourable climatic conditions by the development of bigger inflorescences.

  2. Cultivation of mammalian cells using a single-use pneumatic bioreactor system.

    Science.gov (United States)

    Obom, Kristina M; Cummings, Patrick J; Ciafardoni, Janelle A; Hashimura, Yasunori; Giroux, Daniel

    2014-10-10

    Recent advances in mammalian, insect, and stem cell cultivation and scale-up have created tremendous opportunities for new therapeutics and personalized medicine innovations. However, translating these advances into therapeutic applications will require in vitro systems that allow for robust, flexible, and cost effective bioreactor systems. There are several bioreactor systems currently utilized in research and commercial settings; however, many of these systems are not optimal for establishing, expanding, and monitoring the growth of different cell types. The culture parameters most challenging to control in these systems include, minimizing hydrodynamic shear, preventing nutrient gradient formation, establishing uniform culture medium aeration, preventing microbial contamination, and monitoring and adjusting culture conditions in real-time. Using a pneumatic single-use bioreactor system, we demonstrate the assembly and operation of this novel bioreactor for mammalian cells grown on micro-carriers. This bioreactor system eliminates many of the challenges associated with currently available systems by minimizing hydrodynamic shear and nutrient gradient formation, and allowing for uniform culture medium aeration. Moreover, the bioreactor's software allows for remote real-time monitoring and adjusting of the bioreactor run parameters. This bioreactor system also has tremendous potential for scale-up of adherent and suspension mammalian cells for production of a variety therapeutic proteins, monoclonal antibodies, stem cells, biosimilars, and vaccines.

  3. Antagonistic interactions between endophytic cultivable bacterial communities isolated from the medicinal plant Echinacea purpurea.

    Science.gov (United States)

    Maida, Isabel; Chiellini, Carolina; Mengoni, Alessio; Bosi, Emanuele; Firenzuoli, Fabio; Fondi, Marco; Fani, Renato

    2016-09-01

    In this work we have studied the antagonistic interactions existing among cultivable bacteria isolated from three ecological niches (rhizospheric soil, roots and stem/leaves) of the traditional natural medicinal plant Echinacea purpurea. The three compartments harboured different taxonomic assemblages of strains, which were previously reported to display different antibiotic resistance patterns, suggesting the presence of differential selective pressure due to antagonistic molecules in the three compartments. Antagonistic interactions were assayed by the cross-streak method and interpreted using a network-based analysis. In particular 'within-niche inhibition' and 'cross-niche inhibition' were evaluated among isolates associated with each compartment as well as between isolates retrieved from the three different compartments respectively. Data obtained indicated that bacteria isolated from the stem/leaves compartment were much more sensitive to the antagonistic activity than bacteria from roots and rhizospheric soil. Moreover, both the taxonomical position and the ecological niche might influence the antagonistic ability/sensitivity of different strains. Antagonism could play a significant role in contributing to the differentiation and structuring of plant-associated bacterial communities. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  4. Developments in techniques for the isolation, enrichment, main culture conditions and identification of spermatogonial stem cells

    OpenAIRE

    He, Yanan; Chen, Xiaoli; Zhu, Huabin; Wang, Dong

    2015-01-01

    The in vitro culture system of spermatogonial stem cells (SSCs) provides a basis for studies on spermatogenesis, and also contributes to the development of new methods for the preservation of livestock and animal genetic modification. In vitro culture systems have mainly been established for mouse SSCs, but are lacking for farm animals. We reviewed and analyzed the current progress in SSC techniques such as isolation, purification, cultivation and identification. Based on the published studie...

  5. Derivation of the human embryonic stem cell line RCe012-A (RC-8)

    OpenAIRE

    P.A. De Sousa; B.J. Tye; Bruce, K.; P. Dand; RUSSELL, G.; Collins, D. M.; Greenshields, A.; H. Bradburn; J.M. Downie; M. Bateman; A. Courtney

    2016-01-01

    The human embryonic stem cell line RCe012-A (RC-8) was derived from a frozen and thawed day 5 embryo cultivated to the blastocyst stage. The embryo was voluntarily donated as unsuitable and surplus to fertility requirements following ethics committee approved informed consent under licence from the UK Human Fertilisation and Embryology Authority. The cell line shows normal pluripotency marker expression and differentiation to the three germ layers in vitro. It has a normal 46XX female karyoty...

  6. High-density polymer microarrays: identifying synthetic polymers that control human embryonic stem cell growth.

    Science.gov (United States)

    Hansen, Anne; Mjoseng, Heidi K; Zhang, Rong; Kalloudis, Michail; Koutsos, Vasileios; de Sousa, Paul A; Bradley, Mark

    2014-06-01

    The fabrication of high-density polymer microarray is described, allowing the simultaneous and efficient evaluation of more than 7000 different polymers in a single-cellular-based screen. These high-density polymer arrays are applied in the search for synthetic substrates for hESCs culture. Up-scaling of the identified hit polymers enables long-term cellular cultivation and promoted successful stem-cell maintenance. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Immunohistochemical markers for corneal stem cells in the early developing human eye

    DEFF Research Database (Denmark)

    Lyngholm, Mikkel; Høyer, Poul E; Vorum, Henrik;

    2008-01-01

    markers and potential markers for LSCs and early transient amplifying cells in human adults. In this study, we describe the development of the ectodermally derived LSCs and the mesodermally derived niche cells from the time at which the cornea is defined (week 6) until the formation of the early limbal...... niche (week 14) in human embryos and fetuses. The expression of SOD2 and CK15 was investigated together with other recently identified limbal proteins. Previously suggested LSC and differentiation markers (PAX6, aquaporin-1 and nestin) were also investigated. Both SOD2 and CK15 were present...

  8. On Cultivating Students' Motivation in Second Language Acquisition

    Institute of Scientific and Technical Information of China (English)

    沈小平

    2009-01-01

    This paper attempts to explore the cultivation of motivation in second language acquisition based on shedding new light on the definition, the importance, and the classification of learners' motivation in second language acquisition.

  9. Microalgal cultivation with biogas slurry for biofuel production.

    Science.gov (United States)

    Zhu, Liandong; Yan, Cheng; Li, Zhaohua

    2016-11-01

    Microalgal growth requires a substantial amount of chemical fertilizers. An alternative to the utilization of fertilizer is to apply biogas slurry produced through anaerobic digestion to cultivate microalgae for the production of biofuels. Plenty of studies have suggested that anaerobic digestate containing high nutrient contents is a potentially feasible nutrient source to culture microalgae. However, current literature indicates a lack of review available regarding microalgal cultivation with biogas slurry for the production of biofuels. To help fill this gap, this review highlights the integration of digestate nutrient management with microalgal production. It first unveils the current status of microalgal production, providing basic background to the topic. Subsequently, microalgal cultivation technologies using biogas slurry are discussed in detail. A scale-up scheme for simultaneous biogas upgrade and digestate application through microalgal cultivation is then proposed. Afterwards, several uncertainties that might affect this practice are explored. Finally, concluding remarks are put forward.

  10. Bionic optimization research of soil cultivating component design

    Institute of Scientific and Technical Information of China (English)

    GUO ZhiJun; ZHOU ZhiLi; ZHANG Yi; LI ZhongLi

    2009-01-01

    The basic biomechanical laws that apply to the clawed toes of animals with powerful digging abilities and the optimal bionic design of curved soil cultivating components with an analogous contour were researched in a novel way. First, the curvature and profile of the inside contour line of a field mouse's clawed toe were analyzed. The finite element method (FEM) was then used to simulate the working process in order to study the changing characteristics of the working resistance of bionic soil-engaging surfaces and the stress field of the processed soil. A straight-line cultivating component was used for comparative analysis. In accordance with the simulation results, a series of soil cultivating components of varying design were manufactured. An indoor soil bin experiment was carried out to measure their working resistance and validate the results of the FEM analysis. The results of this research would have important values in the optimization design of cultivating components for energy and cost savings.

  11. Nitrous oxide emissions from rapeseed cultivation in Germany

    Science.gov (United States)

    Fuß, Roland; Andres, Monique; Hegewald, Hannes; Kesenheimer, Katharina; Koebke, Sarah; Räbiger, Thomas; Suárez Quiñones, Teresa; Walter, Katja; Stichnothe, Heinz; Flessa, Heinz

    2016-04-01

    About 12 % of Germany's agricultural area is used for rapeseed cultivation and two third of the harvest is converted to biodiesel. Due to requirements of the EU Renewables Directive the greenhouse gas (GHG) balance of rapeseed cultivation must be reported and sustainability criteria and GHG savings compared to fossil fuel must be achieved and certified. Current certified methodology estimates N2O field emissions from rapeseed cultivation using the IPCC Tier 1 approach based on a global emission factor (N2O emission per unit nitrogen fertilizer input) of 1 %, which is not specific for the crop. We present results from three years of measurements (2013 - 2015) on five field trials in Germany, which combined with data from a meta-analysis suggest that GHG emission factors of German rapeseed cultivation are lower than thought previously. Furthermore, results suggest that substitution of mineral fertilizers with organic fertilizers is a valid mitigation option since it avoids GHG emissions during production of mineral fertilizers.

  12. Cultivation of Pleurotus ostreatus and other edible mushrooms.

    Science.gov (United States)

    Sánchez, Carmen

    2010-02-01

    Pleurotus ostreatus is the second most cultivated edible mushroom worldwide after Agaricus bisporus. It has economic and ecological values and medicinal properties. Mushroom culture has moved toward diversification with the production of other mushrooms. Edible mushrooms are able to colonize and degrade a large variety of lignocellulosic substrates and other wastes which are produced primarily through the activities of the agricultural, forest, and food-processing industries. Particularly, P. ostreatus requires a shorter growth time in comparison to other edible mushrooms. The substrate used for their cultivation does not require sterilization, only pasteurization, which is less expensive. Growing oyster mushrooms convert a high percentage of the substrate to fruiting bodies, increasing profitability. P. ostreatus demands few environmental controls, and their fruiting bodies are not often attacked by diseases and pests, and they can be cultivated in a simple and cheap way. All this makes P. ostreatus cultivation an excellent alternative for production of mushrooms when compared to other mushrooms.

  13. Mini Review: Innovation technology cultivation of durio in East Kalimantan

    Directory of Open Access Journals (Sweden)

    AFRILIA TRI WIDYAWATI

    2017-03-01

    Full Text Available Abstract. Widyawati AT, Nurbani. 2017. . Pros Sem Nas Masy Biodiv Indon 3: 132-137. Durian is native of the region where the climate is tropical wet, especially in Indonesia, Malaysia and Thailand. Durian plant species most widely known and cultivated in Indonesia is Durio zibethinus Murr. Improve the quality of fruit production in sufficient quantity to do with the increase in population as well as increasing fruit crop cultivation technology do. In addition to ensuring that products are safe to eat fruit cultivation technology needs to be done in an environmentally responsible in accordance with the SOP (Standard Operating Procedure and the concept of cultivation of GAP (Good Agriculture Practice.

  14. Cultivation of Agaricus bisporus on some compost formulas and ...

    African Journals Online (AJOL)

    SERVER

    2007-10-04

    Oct 4, 2007 ... the basidiomycete fungus Agaricus bisporus are pro- duced in large ... selective and pathogen free substrate (Randle and. Hayes, 1972 ..... Development of mushroom cultivation techniques in Eastern Black Sea Region of.

  15. Genetic analysis of wild and cultivated germplasm of pigeonpea ...

    African Journals Online (AJOL)

    Ezedom Theresa

    Lens sp. (Sharma et al., 1995; Ahmad et al., 1996),. Phaseolus sp. (Beebe et al., 2000; Chiorato et al., 2007), ..... cultivated ICP 7543 and ICP 14144 revealed the highest ... Akkaya MS, Shoemaker RC, Specht JE, Bhagwat AA, Cregan PB.

  16. Cultivation, isolation and characterization of bacteriocin from fresh ...

    African Journals Online (AJOL)

    Cultivation, isolation and characterization of bacteriocin from fresh cow milk and meat samples obtained from Lapai Market in Niger State Nigeria. ... effective against predominant food spoilers (Saccharomyces, Pseudomonas, Klebsiella and ...

  17. Cultivation of live food organisms - status and scope in India

    Digital Repository Service at National Institute of Oceanography (India)

    Sumitra-Vijayaraghavan

    In the hatchery production of cultivable shell-fishes and fin-fishes, a reliable and continuous supply of live food of appropriate size is of importance. The organisms cultured as live feed presently in India are the microalgae, turbellarians...

  18. Valve stem and packing assembly

    Energy Technology Data Exchange (ETDEWEB)

    Wordin, J.J.

    1990-12-31

    A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele`s pivot. The Schiele`s pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele`s pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele`s pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents overtightening of the retaining nut and the resulting excessive friction between stem and stem packing.

  19. QUALITY EVALUATION OF STEVIA REBAUDIANA CULTIVATED IN FARMERS FIELD

    Directory of Open Access Journals (Sweden)

    Chauhan Nirpendra

    2011-05-01

    Full Text Available Among the potential industrial crops Stevia rebaudiana introduce in newly develop state Uttarakand for cultivated as well as quality evaluations of farmers produced and its comparative assessment with other parts of northern areas. Stevia rebaudiana is a natural, non-caloric, sweet-tasting plant used globally for its sweeter properties. Stevia rebaudiana cultivated in different region of north India, stevioside vary 6.0- 9.5%, rebaudioside vary ranging 1.60-3.90 % within different location.

  20. Cultivating the Grapevine: An Analysis of Rumor Principles and Concepts

    Science.gov (United States)

    2015-12-01

    NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited CULTIVATING THE...REPORT TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE CULTIVATING THE GRAPEVINE: AN ANALYSIS OF RUMOR PRINCIPLES AND CONCEPTS 5...Specifically, this study draws from a review of current and historical literature on rumor theory to distill a set of principles to guide the successful

  1. Impact of Olive Cultivation on Biodiversity in Messenia, Greece

    OpenAIRE

    Kjellström, Felicia

    2014-01-01

    The biggest threat and cause to loss of biodiversity have been found to be the intensification of agriculture under the 20th century. Messenia is one of the oldest olive cultivation areas in Greece and the landscape is dominated by olive groves characterized by extensive tillage, which causes serious erosion and might be a threat to plant diversity. Organic olive cultivation is an alternative that aims to preserve and support biodiversity. In this study the plant composition in the edge zones...

  2. Cultivation of Pleurotus on agricultural substrates in Cuba

    OpenAIRE

    R. C. Bermúdez; García, N.; Gross, P.; Serrano, M

    2001-01-01

    Pleurotus ostreatus f. sp. florida (P-184) was cultivated on several agricultural substrates, such as coffee pulp, cocoa shells, and coconut shells. These substrates were processed by solar drying, stored, pasteurized, and used for mushroom cultivation. The highest biological efficiencies were recorded on coffee pulp from Coffea arabica (168.5-179.4%), followed by coconut shells (90.0%), and cocoa shells (84.5%; particle size: > 4 mm).

  3. Nutrient Recovery of Starch Processing Waste to Cordyceps militaris: Solid State Cultivation and Submerged Liquid Cultivation.

    Science.gov (United States)

    Lee, Joonyeob; Cho, Kyungjin; Shin, Seung Gu; Bae, Hyokwan; Koo, Taewoan; Han, Gyuseong; Hwang, Seokhwan

    2016-09-01

    This study demonstrated the potential for managing starch processing waste (SPW) by bioconversion to Cordyceps militaris mycelia using solid state cultivation (SSC) and submerged liquid cultivation (SLC). The growth characteristics of C. militaris mycelium were accessed and compared for SSC and SLC systems on SPW under various conditions of initial SPW concentration, pH, and operating temperature. To quantify the mycelial biomass in SLC, original primer sets targeting the 18S rRNA gene of C. militaris were developed. In SSC, a maximum mycelial growth rate (543.1 mm(2)/day) was predicted to occur at 25.6 g SPW/L, pH 5.5, and 23.8 °C. In SLC, a maximum mycelial growth rate (1918.6 mg/L/day) was predicted to occur at 35.5 g SPW/L, pH 5.5, and 22.0 °C. Temperature was suggested as the most significant factor in both systems. The higher optimum substrate concentration observed for SLC than for SSC was likely due to difference in mycelial morphology and mixing effect.

  4. Continuous cultivation of photosynthetic microorganisms: Approaches, applications and future trends.

    Science.gov (United States)

    Fernandes, Bruno D; Mota, Andre; Teixeira, Jose A; Vicente, Antonio A

    2015-11-01

    The possibility of using photosynthetic microorganisms, such as cyanobacteria and microalgae, for converting light and carbon dioxide into valuable biochemical products has raised the need for new cost-efficient processes ensuring a constant product quality. Food, feed, biofuels, cosmetics and pharmaceutics are among the sectors that can profit from the application of photosynthetic microorganisms. Biomass growth in a photobioreactor is a complex process influenced by multiple parameters, such as photosynthetic light capture and attenuation, nutrient uptake, photobioreactor hydrodynamics and gas-liquid mass transfer. In order to optimize productivity while keeping a standard product quality, a permanent control of the main cultivation parameters is necessary, where the continuous cultivation has shown to be the best option. However it is of utmost importance to recognize the singularity of continuous cultivation of cyanobacteria and microalgae due to their dependence on light availability and intensity. In this sense, this review provides comprehensive information on recent breakthroughs and possible future trends regarding technological and process improvements in continuous cultivation systems of microalgae and cyanobacteria, that will directly affect cost-effectiveness and product quality standardization. An overview of the various applications, techniques and equipment (with special emphasis on photobioreactors) in continuous cultivation of microalgae and cyanobacteria are presented. Additionally, mathematical modeling, feasibility, economics as well as the applicability of continuous cultivation into large-scale operation, are discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Feasibility of attached cultivation for polysaccharides production by Porphyridium cruentum.

    Science.gov (United States)

    Lutzu, Giovanni Antonio; Zhang, Lanlan; Zhang, Zhaohui; Liu, Tianzhong

    2017-01-01

    Porphyridium cruentum is one of the most valued microalgae species able to produce both pigments and exopolysaccharides. Conventional liquid suspended cultivation in ponds and photobioreactors show its disadvantages in lower cultivation efficiency and higher stirring power consumption due to the high viscosity of the medium by the accumulation of polysaccharides. In this work, a new method of culture (called attached cultivation) based on the growth of microalgae using a supporting surface was successfully applied to the cultivation of P. cruentum and the effect of the main influential parameters on its growth rate and polysaccharides production has been investigated. Higher values of these factors resulted in a faster growth rate and, in particular, optimum values of 6.98 g m(-2) for initial biomass density, 100 µmol m(-2) s(-1) for light intensity, continuous illumination, 2.0 % for CO2 concentration, and 0.1 v v(-1) min(-1) for aeration rate produced the best polysaccharide production of 42 % dry weight. The nutrition profile of P. cruentum obtained in attached and suspended cultivations was similar. Overall these results demonstrate that the attached cultivation is a promising technique which greatly improves the growth rate of P. cruentum as well as its production of polysaccharides and, therefore, it is worth enhancing to be exploited for commercial application.

  6. Attached cultivation for improving the biomass productivity of Spirulina platensis.

    Science.gov (United States)

    Zhang, Lanlan; Chen, Lin; Wang, Junfeng; Chen, Yu; Gao, Xin; Zhang, Zhaohui; Liu, Tianzhong

    2015-04-01

    To improve cultivation efficiency for microalgae Spirulina platensis is related to increase its potential use as food source and as an effective alternative for CO2 fixation. The present work attempted to establish a technique, namely attached cultivation, for S. platensis. Laboratory experiments were made firstly to investigate optimal conditions on attached cultivation. The optimal conditions were found: 25 g m(-2) for initial inoculum density using electrostatic flocking cloth as substrata, light intensity lower than 200 μmol m(-2) s(-1), CO2 enriched air flow (0.5%) at a superficial aeration rate of 0.0056 m s(-1) in a NaHCO3-free Zarrouk medium. An outdoor attached cultivation bench-scale bioreactor was built and a 10d culture of S. platensis was carried out with daily harvesting. A high footprint areal biomass productivity of 60 g m(-2) d(-1) was obtained. The nutrition of S. platensis with attached cultivation is identical to that with conventional liquid cultivation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Application of Remote Sensing Techniques for Mapping Shifting Cultivation

    Directory of Open Access Journals (Sweden)

    N.Vijaya Kumari

    2017-01-01

    Full Text Available Shifting cultivation is an ancient and primitive method of cultivation, also referred to as ‘slash and burn’ or ‘rotational bush fallow agricultural system’. The practice mainly involves removal of the forests by primitive slash and burn technique followed by mixed cropping for short period before abandoning the site. Tribals all over India are known to follow the practice of shifting cultivation with some regional variations. The present study has been undertaken to estimate the spatial distribution of podu cultivation in Srikakulam district of Andhra Pradesh by using remote sensing techniques. Results of the present study indicate that an estimated area of 10,491.857 acres of the forest area is under shifting cultivation in Srikakulam district. Shifting cultivation has caused a great deal of environmental degradation. Remote sensing techniques with repetitive coverage and synoptic view provide database for assessing environment degrading practices. Mapping of shifting areas is important not only from ecological point of view but also for management purposes.

  8. [Ethical problems raised by new reproductive biotechnologies and stem cells].

    Science.gov (United States)

    Le Douarin, Nicole M

    2015-01-01

    Research about the hormonal mechanisms controlling reproduction in mammals has soared during the first half of the 20th century. It has produced a series of discoveries with important outcomes, not only scientific, but also impacting the ways of life. Besides the advent of the contraceptive pill, it has permitted to isolate and cultivate in vitro the female gamete, to fertilize it, thus obtaining a zygote that continues to develop until the blastocyst stage outside the maternal organism. The embryo, transferred into a foster-mother, develops normally until term: the first "test-tube baby" was born in this way in 1978. But the only fact of being able to cultivate the human egg in vitro was to open other possibilities and allow further biological advances: embryonic stem cells (ES cells) obtained from blastocysts and, more recently, from induced Pluripotent Stem cells (iPS), which can potentially be derived from all types of differentiated cell types obtained from adult individuals. From then on, the advent of a new medicine could be anticipated, regenerative because able to replace deficient or absent cells within the organism. As each of these steps was reached, scientists have encountered vigorous opposition from the people: the new potentials disturbed the conceptions that man had of his relationship to nature, in particular in two sensitive domains: sexuality and reproduction. The progress of science has however been accepted by most as soon as it was understood that humanity could anticipate advantages from these advances.

  9. [The application of stem cells for research and treatment of neurological disorders].

    Science.gov (United States)

    Sveinsson, Olafur A; Gudjonsson, Thorarinn; Petersen, Petur Henry

    2008-02-01

    It has long been a common view that neurons in the human central nervous system were not capable of self renewal. But in the mid-1990s scientists discovered that certain areas of the human brain do have the ability generate new neurons, at least under certain circumstances. It was subsecuently confirmed that the human central nervous system contains stem cells similar to the cells which originally give rise to the central nervous sysem during fetal development. The possible use of stem cells in the treatment of various neurological disorders, holds great promise. However, much research needs to be carried out before stem cell therapy can be moved from the bench to the bedside. Now researchers are pursuing two fundamental strategies to exploit the possible application of stem cells. One is to cultivate stem cells in vitro and to design the right differentiation profile of cells suitable for implantation. The other strategy relies on studying endogenous signals that could stimulate the patient s own stem cells and repair mechanisms. Here we give an overview of neural stem cells and their possible future use in the treatment of neural diseases such as Parkinson s disease, motor neuron disease and spinal cord injury.

  10. Telomere Attrition Occurs during Ex Vivo Expansion of Human Dental Pulp Stem Cells

    Directory of Open Access Journals (Sweden)

    Jaroslav Mokry

    2010-01-01

    Full Text Available We provide a detailed characteristic of stem cells isolated and expanded from the human dental pulp. Dental pulp stem cells express mesenchymal cell markers STRO-1, vimentin, CD29, CD44, CD73, CD90, CD166, and stem cell markers Sox2, nestin, and nucleostemin. They are multipotent as shown by their osteogenic and chondrogenic potential. We measured relative telomere length in 11 dental pulp stem cell lines at different passages by quantitative real-time PCR. Despite their large proliferative capacity, stable viability, phenotype, and genotype over prolonged cultivation, human dental pulp stem cells suffer from progressive telomere shortening over time they replicate in vitro. Relative telomere length (T/S was inversely correlated with cumulative doubling time. Our findings indicate that excessive ex vivo expansion of adult stem cells should be reduced at minimum to avoid detrimental effects on telomere maintenance and measurement of telomere length should become a standard when certificating the status and replicative age of stem cells prior therapeutic applications.

  11. Rat hair follicle stem cells differentiate and promote recovery following spinal cord injury

    Institute of Scientific and Technical Information of China (English)

    Nowruz Najafzadeh; Maliheh Nobakht; Bagher Pourheydar; Mohammad Ghasem Golmohammadi

    2013-01-01

    Emerging studies of treating spinal cord injury (SCI) with adult stem cells led us to evaluate the effects of transplantation of hair fol icle stem cells in rats with a compression-induced spinal cord lesion. Here, we proposed a hypothesis that rat hair fol icle stem celltransplantation can promote the recovery of injured spinal cord. Compression-induced spinal cord injury was induced in Wistar rats in this study. The bulge area of the rat vibrissa fol icles was isolated, cultivated and characterized with nestin as a stem cellmarker. 5-Bromo-2′-deoxyuridine (BrdU) labeled bulge stem cells were transplanted into rats with spinal cord injury. Immunohistochemical staining results showed that some of the grafted cells could survive and differentiate into oligodendrocytes (receptor-interacting protein positive cells) and neuronal-like cells (βIII-tubulin positive cells) at 3 weeks after transplantation. In addition, recovery of hind limb locomotor function in spinal cord injury rats at 8 weeks fol owing celltransplantation was assessed using the Basso, Beattie and Bresnahan (BBB) locomotor rating scale. The results demon-strate that the grafted hair fol icle stem cells can survive for a long time period in vivo and differentiate into neuronal- and glial-like cells. These results suggest that hair fol icle stem cells can promote the recovery of spinal cord injury.

  12. Bioremediation efficiency of the largest scale artificial Porphyra yezoensis cultivation in the open sea in China.

    Science.gov (United States)

    Wu, Hailong; Huo, Yuanzi; Zhang, Jianheng; Liu, Yuanyuan; Zhao, Yating; He, Peimin

    2015-06-15

    The bioremediation efficiency of China's largest scale Porphyra yezoensis cultivation for removing dissolved nutrients and controlling harmful algae was studied in the radial sandbanks waters of Jiangsu Province in the year 2012-2013. Mean nutrient concentration values in the P. yezoensis cultivation area were significantly lower than those in the non-cultivation area, especially during the cultivation season (popen sea.

  13. Improving the shallot and hot pepper cultivation system in the coastal plain of Northern Java

    NARCIS (Netherlands)

    Putter, de H.; Witono, A.

    2013-01-01

    This report aims to improve cultivation and to enhance farmers' income in the Brebes region of Northern Java. First, a brief description of vegetable cultivation in the Brebes region is given. Also profits of vegetable cultivation are discussed and bottlenecks in the current cultivation system. In

  14. Genotypic diversity among rhizospheric bacteria of three legumes assessed by cultivation-dependent and cultivation-independent techniques.

    Science.gov (United States)

    Pongsilp, Neelawan; Nimnoi, Pongrawee; Lumyong, Saisamorn

    2012-02-01

    The genotypic diversity of rhizospheric bacteria of 3 legumes including Vigna radiata, Arachis hypogaea and Acacia mangium was compared by using cultivation-dependent and cultivation-independent methods. For cultivation-dependent method, Random amplified polymorphic DNA (RAPD) profiles revealed that the bacterial genetic diversity of V. radiata and A. mangium rhizospheres was higher than that of A. hypogaea rhizosphere. For cultivation-independent method, Denaturing gradient gel electrophoresis (DGGE) profiles of PCR-amplified 16S rRNA genes revealed the difference in bacterial community and diversity of rhizospheres collected from 3 legumes. The ribotype richness which indicates species diversity, was highest in V. radiata rhizosphere, followed by A. hypogaea and A. mangium rhizospheres, respectively. Three kinds of media were used to cultivate different target groups of bacteria. The result indicates that the communities of cultivable bacteria in 3 rhizospheres recovered from nutrient agar (NA) medium were mostly different from each other, while Bradyrhizobium selective medium (BJSM) and nitrogen-free medium shaped the communities of cultivable bacteria. Nine isolates grown on BJSM were identified by 16S rRNA gene sequence analysis. These isolates were very closely related (with 96% to 99% identities) to either one of the three groups including Cupriavidus-Ralstonia group, Bacillus group and Bradyrhizobium-Bosea-Afipia group. The rhizospheres were also examined for their enzymatic patterns. Of 19 enzymes tested, 3 rhizospheres were distinguishable by the presence or the absence of leucine acrylamidase and acid phosphatase. The selected cultivable bacteria recovered from NA varied in their abilities to produce indole-acetic acid and ammnonia. The resistance to 10 antibiotics was indistinguishable among bacteria isolated from different rhizospheres.

  15. A novel rat fibrosarcoma cell line from transformed bone marrow-derived mesenchymal stem cells with maintained in vitro and in vivo stemness properties.

    Science.gov (United States)

    Wang, Meng-Yu; Nestvold, Janne; Rekdal, Øystein; Kvalheim, Gunnar; Fodstad, Øystein

    2017-03-15

    Increasing evidence suggests a possible relationship between mesenchymal stem cells (MSCs) and sarcoma. MSCs are hypothesized to be the cells initiating sarcomagenesis, and cancer stem cells (CSCs) sharing features of MSCs have been identified in sarcomas. Here, we report on the characteristics of a bone marrow-derived rat mesenchymal stem cell line that spontaneously transformed in long-term culture. The rat transformed mesenchymal stem cells (rTMSCs) produced soft-tissue fibrosarcomas in immunocompromised mice and immunocompetent rats. In vitro, the rTMSCs displayed increased proliferation capacity compared to the untransformed cell line. The transformed MSCs maintained the mesenchymal phenotype by expression of the stem cell marker CD 90 and the lack of hematopoietic and endothelial markers. Cytogenetic analysis detected trisomy 6 in the rTMSCs. Side population (SP) isolation and tumorsphere cultivation of the transformed cells confirmed the presence of CSCs among the rTMSCs. Importantly, the rTMSCs retained their differentiation capacity towards osteogenic and adipogenic lineages. This transformed MSC-based cell line may be valuable in examining the balance in a mixed cell population between cancer stem cell properties and the ability to differentiate to specific non-transformed cell populations. Moreover, it may also be a useful tool to evaluate the efficacy of novel targeted immunotherapies in vivo. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. A native-like corneal construct using donor corneal stroma for tissue engineering.

    Directory of Open Access Journals (Sweden)

    Jing Lin

    Full Text Available Tissue engineering holds great promise for corneal transplantation to treat blinding diseases. This study was to explore the use of natural corneal stroma as an optimal substrate to construct a native like corneal equivalent. Human corneal epithelium was cultivated from donor limbal explants on corneal stromal discs prepared by FDA approved Horizon Epikeratome system. The morphology, phenotype, regenerative capacity and transplantation potential were evaluated by hematoxylin eosin and immunofluorescent staining, a wound healing model, and the xeno-transplantation of the corneal constructs to nude mice. An optically transparent and stratified epithelium was rapidly generated on donor corneal stromal substrate and displayed native-like morphology and structure. The cells were polygonal in the basal layer and became flattened in superficial layers. The epithelium displayed a phenotype similar to human corneal epithelium in vivo. The differentiation markers, keratin 3, involucrin and connexin 43, were expressed in full or superficial layers. Interestingly, certain basal cells were immunopositive to antibodies against limbal stem/progenitor cell markers ABCG2 and p63, which are usually negative in corneal epithelium in vivo. It suggests that this bioengineered corneal epithelium shared some characteristics of human limbal epithelium in vivo. This engineered epithelium was able to regenerate in 4 days following from a 4mm-diameter wound created by a filter paper soaked with 1 N NaOH. This corneal construct survived well after xeno-transplantation to the back of a nude mouse. The transplanted epithelium remained multilayer and became thicker with a phenotype similar to human corneal epithelium. Our findings demonstrate that natural corneal stroma is an optimal substrate for tissue bioengineering, and a native-like corneal construct has been created with epithelium containing limbal stem cells. This construct may have great potential for clinical use in

  17. PTEN, Stem Cells, and Cancer Stem Cells*S⃞

    OpenAIRE

    Hill, Reginald; Wu, Hong

    2009-01-01

    Like normal stem cells, “cancer stem cells” have the capacity for indefinite proliferation and generation of new cancerous tissues through self-renewal and differentiation. Among the major intracellular signaling pathways, WNT, SHH, and NOTCH are known to be important in regulating normal stem cell activities, and their alterations are associated with tumorigenesis. It has become clear recently that PTEN (phosphatase and tensin homologue) is also critical for stem cell...

  18. Melanoma stem cells.

    Science.gov (United States)

    Roesch, Alexander

    2015-02-01

    The cancer stem cell concept significantly broadens our understanding of melanoma biology. However, this concept should be regarded as an integral part of a holistic cancer model that also includes the genetic evolution of tumor cells and the variability of cell phenotypes within a dynamic tumor microenvironment. The biologic complexity and methodological difficulties in identifying cancer stem cells and their biomarkers are currently impeding the direct translation of experimental findings into clinical practice. Nevertheless, it is these methodological shortcomings that provide a new perspective on the phenotypic heterogeneity and plasticity of melanoma with important consequences for future therapies. The development of new combination treatment strategies, particularly with regard to overcoming treatment resistance, could significantly benefit from targeted elimination of cell subpopulations with cancer stem cell properties. © 2015 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

  19. Aneuploidy in stem cells

    Institute of Scientific and Technical Information of China (English)

    Jorge; Garcia-Martinez; Bjorn; Bakker; Klaske; M; Schukken; Judith; E; Simon; Floris; Foijer

    2016-01-01

    Stem cells hold enormous promise for regenerative medicine as well as for engineering of model systems to study diseases and develop new drugs. The discovery of protocols that allow for generating induced pluripotent stem cells(IPSCs) from somatic cells has brought this promise steps closer to reality. However,as somatic cells might have accumulated various chromosomal abnormalities,including aneuploidies throughout their lives,the resulting IPSCs might no longer carry the perfect blueprint for the tissue to be generated,or worse,become at risk of adopting a malignant fate. In this review,we discuss the contribution of aneuploidy to healthy tissues and how aneuploidy can lead to disease. Furthermore,we review the differences between how somatic cells and stem cells respond to aneuploidy.

  20. Stem Properties of Autobacteria

    Directory of Open Access Journals (Sweden)

    Boris A. Berdichevskyy

    2014-03-01

    Full Text Available This paper discusses the stem properties of the autobacteria as part of the activation syndrome and persistence of the endogenous microflora in the adaptation process of the macroorganism to stress, as well as the ability of the bacteria to stimulate the cells of the macroorganism to manifest stem properties. The essence of this syndrome involves testing the tissue with the autobacteria of their "host" body to identify the foci of cellular insolvency with the subsequent inclusion of the autostrains in the implementation phase of the catabolic and anabolic inflammations. Considering the genetic tropism of the microbes to the organ-specific tissue of the area affected, the existence of the stem properties of the autobacteria is assumed to be realized in the process of reparative regeneration. The great clinical significance of further study of this phenomenon is not excluded.

  1. Alternative method for vegetables cultivation in Benin

    Directory of Open Access Journals (Sweden)

    Lucia Recchia

    2013-09-01

    Full Text Available In the developing countries populations, which are already vulnerable and food insecure, are likely to be the most seriously affected by the effects of climate change, e.g. yield decreases and price increases for the most important agricultural crops. The IPCC’s Fourth Assessment Report for Africa describes a trend of warming at a rate faster than the global average and increasing aridity: in many parts of Africa, it seems that warmer climates and changes in precipitation will destabilise agricultural production and aggravates food security. The present work concerns the vegetables cultivation in the Parakou region in Benin, where agriculture employs approximately 70% of the active population and contributes to 36% of the Gross Domestic Product and 88% of export earnings. However, the agricultural sector has been regarded as unproductive with low adaptation capacities because of structural factors (e.g. high level of poverty among rural populations, weak mechanization and intensification of production modes, but also because of natural constraints (e.g. poor management of water and soils, leading to soil degradation. Considering the aridity, the low carbon content and the reduced level of nutrients available in the soil, the use of an hydroponic module has been hypothesised. In this way sufficient yields of the crops may be assured and no agricultural machines will be needed for the tillage operations. In addition, the nutrients can be added to the growing solution using residual materials as poultry manure, ashes and green wastes. In order to verify if some construction or maintenance problems can occur and if a growing solution can be easily obtained using agricultural wastes, some tests have been carried out. Moreover laboratory analyses have been done for different solutions that may be adopted with different shares of water, poultry manure, ashes and green wastes. The tests have indicated that the hydroponic module could be used in Benin

  2. Canine Adipose Derived Mesenchymal Stem Cells Transcriptome Composition Alterations: A Step towards Standardizing Therapeutic

    Directory of Open Access Journals (Sweden)

    Nina Krešić

    2017-01-01

    Full Text Available Although canine adipose derived stem cells (cASCs morphology characteristics and differentiation ability are well documented, transcriptome alterations of undifferentiated cASCs during ex vivo cultivation remain unknown. Here we demonstrate, for the first time, the transcriptome composition of isolated cASCs in undifferentiated state originating from six donors. Transcriptome changes were monitored during ex vivo cultivation between passage 3 (P3 and P5, which are mostly used in therapy. Influence of donors’ age in given passage number on transcriptome composition was also investigated. Cultivation from P3 to P5 resulted in 16 differentially expressed genes with cooverexpression of pluripotency and self-renewal transcription factors genes SOX2 and POU5F1 dominant in old donors’ cells. Furthermore, cASCs demonstrated upregulation of IL-6 in young and old donors’ cells. In addition, ex vivo cultivation of cASCs revealed well-known morphological alterations accompanied with decrease in expression of CD90 and CD44 markers in P4 and higher monitored by flow cytometry and successful osteo- and chondrodifferentiation but inefficient adipodifferentiation in P3. Our results revealed the impact of ex vivo cultivation on nature of cells. Correlation of transcriptome changes with secretome composition is needed and its further impact on therapeutic potential of cASCs remains to be evaluated in clinical trials.

  3. Stem cell therapy for diabetes

    Directory of Open Access Journals (Sweden)

    K O Lee

    2012-01-01

    Full Text Available Stem cell therapy holds immense promise for the treatment of patients with diabetes mellitus. Research on the ability of human embryonic stem cells to differentiate into islet cells has defined the developmental stages and transcription factors involved in this process. However, the clinical applications of human embryonic stem cells are limited by ethical concerns, as well as the potential for teratoma formation. As a consequence, alternative forms of stem cell therapies, such as induced pluripotent stem cells, umbilical cord stem cells and bone marrow-derived mesenchymal stem cells, have become an area of intense study. Recent advances in stem cell therapy may turn this into a realistic treatment for diabetes in the near future.

  4. Stem cells and healthy aging.

    Science.gov (United States)

    Goodell, Margaret A; Rando, Thomas A

    2015-12-04

    Research into stem cells and aging aims to understand how stem cells maintain tissue health, what mechanisms ultimately lead to decline in stem cell function with age, and how the regenerative capacity of somatic stem cells can be enhanced to promote healthy aging. Here, we explore the effects of aging on stem cells in different tissues. Recent research has focused on the ways that genetic mutations, epigenetic changes, and the extrinsic environmental milieu influence stem cell functionality over time. We describe each of these three factors, the ways in which they interact, and how these interactions decrease stem cell health over time. We are optimistic that a better understanding of these changes will uncover potential strategies to enhance stem cell function and increase tissue resiliency into old age.

  5. The Stem Cell Conundrum

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ At the beginning of this year, Kelly Reynolds,a US-national diagnosed with amyotrophic lateral sclerosis (ALS), became the one of the latest overseas patient to undergo stem cell treatment at the Nanshan Hospital in Shenzhen.Confined to a wheelchair and with limited use of his hands,the 39-year old received four fetal stem cell injections over a three-week period. So far,the results have been positive and Reynolds, acording to his personal blog page, is upbeat about the long-term benefits.

  6. Human mesenchymal stem cells

    DEFF Research Database (Denmark)

    Abdallah, Basem; Kassem, Moustapha

    2008-01-01

    Mesenchymal stem cells (MSC) are a group of clonogenic cells present among the bone marrow stroma and capable of multilineage differentiation into mesoderm-type cells such as osteoblasts, adipocytes and chondrocytes. Due to their ease of isolation and their differentiation potential, MSC are being...... introduced into clinical medicine in variety of applications and through different ways of administration. Here, we discuss approaches for isolation, characterization and directing differentiation of human mesenchymal stem cells (hMSC). An update of the current clinical use of the cells is also provided....

  7. STEM on the radio

    Science.gov (United States)

    Showstack, Randy

    2011-10-01

    Looking for an Internet radio station focusing on programing about science, technology, engineering, and math (STEM)? The U.S. National Science Foundation (NSF) announced on 26 September the launch of Science360 Radio, which it says is the first Internet radio stream dedicated to STEM programing. Science360 includes more than 100 radio shows and podcasts that are available on the Web as well as on iPhone and Android devices. The shows originate from a variety of sources, including NSF, other U.S. government agencies, science organizations, universities, and media outlets. For more information, see http://science360.gov/files/.

  8. Stem Cell Organoid Engineering

    Science.gov (United States)

    Yin, Xiaolei; Mead, Benjamin E.; Safaee, Helia; Langer, Robert; Karp, Jeffrey M.; Levy, Oren

    2016-01-01

    Organoid systems leverage the self-organizing properties of stem cells to create diverse multi-cellular tissue proxies. Most organoid models only represent single or partial components of a tissue, and it is often difficult to control the cell type, organization, and cell-cell/cell-matrix interactions within these systems. Herein, we discuss basic approaches to generate stem cell-based organoids, their advantages and limitations, and how bioengineering strategies can be used to steer the cell composition and their 3D organization within organoids to further enhance their utility in research and therapies. PMID:26748754

  9. STEM--Beyond the Acronym

    Science.gov (United States)

    Vasquez, Jo Anne

    2015-01-01

    When most educators think of STEM education, they think of fully integrated projects seamlessly combining all four disciplines--science, technology, engineering, and mathematics. Although such transdisciplinary STEM units are ideal, writes Vasquez, they are not the only way to give students valuable STEM experiences. She gives examples of two…

  10. Stem cells and genetic diseases

    Directory of Open Access Journals (Sweden)

    Irshad S.

    2012-09-01

    Full Text Available In this review, we have discussed a role of stem cells in the treatment of genetic diseases including cochlear and retinal regeneration. The most perceptive use of stem cells at the genetic diseases is cellular repair of tissues affected by a genetic mutation when stem cells without such mutation are transplanted to restore normal tissue function.

  11. Stem cell organization in Arabidopsis

    NARCIS (Netherlands)

    Wendrich, J.R.

    2016-01-01

    Growth of plant tissues and organs depends on continuous production of new cells, by niches of stem cells. Stem cells typically divide to give rise to one differentiating daughter and one non-differentiating daughter. This constant process of self-renewal ensures that the niches of stem cells or mer

  12. Stem Cell Transplants (For Parents)

    Science.gov (United States)

    ... Teaching Kids to Be Smart About Social Media Stem Cell Transplants KidsHealth > For Parents > Stem Cell Transplants Print A A A What's in this ... Recovery Coping en español Trasplantes de células madre Stem cells are cells in the body that have the ...

  13. Information on Stem Cell Research

    Science.gov (United States)

    ... Home » Current Research » Focus on Research Focus on Stem Cell Research Stem cells possess the unique ability to differentiate into many ... they also retain the ability to produce more stem cells, a process termed self-renewal. There are multiple ...

  14. Enhancing the Urea-N Use Efficiency in Maize (Zea mays Cultivation on Acid Soils Amended with Zeolite and TSP

    Directory of Open Access Journals (Sweden)

    Osumanu H. Ahmed

    2008-01-01

    Full Text Available Ammonia loss significantly reduces the urea-N use efficiency in crop production. Efforts to reduce this problem are mostly laboratory oriented. This paper reports the effects of urea amended with triple superphosphate (TSP and zeolite (Clinoptilolite on soil pH, nitrate, exchangeable ammonium, dry matter production, N uptake, fresh cob production, and urea-N uptake efficiency in maize (Zea mays cultivation on an acid soil in actual field conditions. Urea-amended TSP and zeolite treatments and urea only (urea without additives did not have long-term effect on soil pH and accumulation of soil exchangeable ammonium and nitrate. Treatments with higher amounts of TSP and zeolite significantly increased the dry matter (stem and leaf production of Swan (test crop. All the treatments had no significant effect on urea-N concentration in the leaf and stem of the test crop. In terms of urea-N uptake in the leaf and stem tissues of Swan, only the treatment with the highest amount of TSP and zeolite significantly increased urea-N uptake in the leaf of the test crop. Irrespective of treatment, fresh cob production was statistically not different. However, all the treatments with additives improved urea-N uptake efficiency compared to urea without additives or amendment. This suggests that urea amended with TSP and zeolite has a potential of reducing ammonia loss from surface-applied urea.

  15. Enhancing the urea-N use efficiency in maize (Zea mays) cultivation on acid soils amended with zeolite and TSP.

    Science.gov (United States)

    Ahmed, Osumanu H; Hussin, Aminuddin; Ahmad, Husni M H; Rahim, Anuar A; Majid, Nik Muhamad Abd

    2008-04-20

    Ammonia loss significantly reduces the urea-N use efficiency in crop production. Efforts to reduce this problem are mostly laboratory oriented. This paper reports the effects of urea amended with triple superphosphate (TSP) and zeolite (Clinoptilolite) on soil pH, nitrate, exchangeable ammonium, dry matter production, N uptake, fresh cob production, and urea-N uptake efficiency in maize (Zea mays) cultivation on an acid soil in actual field conditions. Urea-amended TSP and zeolite treatments and urea only (urea without additives) did not have long-term effect on soil pH and accumulation of soil exchangeable ammonium and nitrate. Treatments with higher amounts of TSP and zeolite significantly increased the dry matter (stem and leaf) production of Swan (test crop). All the treatments had no significant effect on urea-N concentration in the leaf and stem of the test crop. In terms of urea-N uptake in the leaf and stem tissues of Swan, only the treatment with the highest amount of TSP and zeolite significantly increased urea-N uptake in the leaf of the test crop. Irrespective of treatment, fresh cob production was statistically not different. However, all the treatments with additives improved urea-N uptake efficiency compared to urea without additives or amendment. This suggests that urea amended with TSP and zeolite has a potential of reducing ammonia loss from surface-applied urea.

  16. Reprogramming triggers endogenous L1 and Alu retrotransposition in human induced pluripotent stem cells.

    Science.gov (United States)

    Klawitter, Sabine; Fuchs, Nina V; Upton, Kyle R; Muñoz-Lopez, Martin; Shukla, Ruchi; Wang, Jichang; Garcia-Cañadas, Marta; Lopez-Ruiz, Cesar; Gerhardt, Daniel J; Sebe, Attila; Grabundzija, Ivana; Merkert, Sylvia; Gerdes, Patricia; Pulgarin, J Andres; Bock, Anja; Held, Ulrike; Witthuhn, Anett; Haase, Alexandra; Sarkadi, Balázs; Löwer, Johannes; Wolvetang, Ernst J; Martin, Ulrich; Ivics, Zoltán; Izsvák, Zsuzsanna; Garcia-Perez, Jose L; Faulkner, Geoffrey J; Schumann, Gerald G

    2016-01-08

    Human induced pluripotent stem cells (hiPSCs) are capable of unlimited proliferation and can differentiate in vitro to generate derivatives of the three primary germ layers. Genetic and epigenetic abnormalities have been reported by Wissing and colleagues to occur during hiPSC derivation, including mobilization of engineered LINE-1 (L1) retrotransposons. However, incidence and functional impact of endogenous retrotransposition in hiPSCs are yet to be established. Here we apply retrotransposon capture sequencing to eight hiPSC lines and three human embryonic stem cell (hESC) lines, revealing endogenous L1, Alu and SINE-VNTR-Alu (SVA) mobilization during reprogramming and pluripotent stem cell cultivation. Surprisingly, 4/7 de novo L1 insertions are full length and 6/11 retrotransposition events occurred in protein-coding genes expressed in pluripotent stem cells. We further demonstrate that an intronic L1 insertion in the CADPS2 gene is acquired during hiPSC cultivation and disrupts CADPS2 expression. These experiments elucidate endogenous retrotransposition, and its potential consequences, in hiPSCs and hESCs.

  17. On Moral Cultivation%论道德教化

    Institute of Scientific and Technical Information of China (English)

    肖会舜

    2015-01-01

    教化不仅在于使人成其为人,更在于使人超越其个体性成为普遍性的精神存在,从而获得真实的自由。通过追溯中西方语境中的教化概念,明晰教化的实质,对传统道德教化与现代性道德教化进行批判性分析,为寻求适应现代伦理精神的道德教化奠定基础。%Cultivation is to make us real human beings and to make people surpass the individuality and become a universal spiritual existence .Therefore ,human beings can get real freedom .Through tracing the concepts of cultivation in both Chinese and Western contexts ,this paper clarifies the nature of cultivation and makes a critical analysis of the traditional and modern moral cultivation to seek a basis for the moral cultivation that suits modern ethical spirit .

  18. Genetic resources in the cultivated flora of the Apuseni Mountains

    Directory of Open Access Journals (Sweden)

    Attila T. SZABO

    1982-08-01

    Full Text Available In order to detect genetic resources formed during specific relations between plant life and human activity in a sample territory situated in the North-Eastern border of the Apuseni Mountains (Transylvania, Romania 416 cultivated plant species were identified and reliable ethnobotanical material was collected. The influence of different geographical regions of the world on the flora of the territory was characterized by an influence index. The influence index "I" of the American, African and Australian species on the spontaneous flora of the sample territory was very low, (I1 = 2,01, but on the cultivated flora it was very high (I2 = 58,48, reflecting the strong impact of foreign floras and agricultures. The cultivated flora of the territory was characterized according to following descriptors: geographical origin, life form, main traditional usage, main place of cultivation, frequency of cultivation, degree of domestication, ethnobotanical knowledge related to different species, local variability, territorial dynamics (related to genetic erosion or sedimentation and territorial distribution.

  19. Cultivation of freshwater microalgae in biodiesel wash water.

    Science.gov (United States)

    Sassi, Patrícia Giulianna Petraglia; Calixto, Clediana Dantas; da Silva Santana, Jordana Kaline; Sassi, Roberto; Costa Sassi, Cristiane Francisca; Abrahão, Raphael

    2017-06-21

    Biodiesel wash water is a contaminating industrial effluent that must be treated prior to disposal. The use of this effluent as a low-cost alternative cultivation medium for microalgae could represent a viable supplementary treatment. We cultivated 11 microalgae species with potential use for biodiesel production to assess their growth capacities in biodiesel industrial washing waters. Only Monoraphidium contortum, Ankistrodesmus sp., Chlorococcum sp., and one unidentified Chlorophyceae species grew effectively in that effluent. M. contortum showed the highest growth capacity and had the second highest fatty acid content (267.9 mg g(-1) of DW), predominantly producing palmitic (20.9%), 7,10,13-hexadecatrienoic (14%), oleic (16.2%), linoleic (10.5%), and linolenic acids (23.2%). In the second phase of the experiment, the microalgae were cultivated in biodiesel wash water at 75% of its initial concentration as well as in WC (control) medium. After 21 days of cultivation, 25.8 and 7.2% of the effluent nitrate and phosphate were removed, respectively, and the chemical oxygen demand was diminished by 31.2%. These results suggest the possibility of cultivating biodiesel producing microalgae in industrial wash water effluents.

  20. Cultivating Microalgae in Domestic Wastewater for Biodiesel Production

    Directory of Open Access Journals (Sweden)

    Soha S.M. MOSTAFA

    2012-02-01

    Full Text Available The objective of this study was to evaluate the growth of nine species of microalgae (green and blue green microalgae on domestic waste water samples obtained from Zenein Waste Water Treatment Plant (ZWWTP, Giza governorate, Egypt. The species were cultivated in different kind of waste water; before treatment; after sterilization; with nutrients with sterilization and with nutrients without sterilization. The experiment was conducted in triplicate and cultures were incubated at 25�1�C under continuous shaking (150 rpm and illumination (2000 Lux for 15 days. pH, electric conductivity (EC, optical density (OD , dry weight (DW, were done at the time of incubation and at the end of experiment, in addition to determine the percentage of lipid and biodiesel. The data revealed that, domestic waste water with nutrient media (T3 was promising for cultivation of five algal species when compared with conventional media, Moreover, domestic waste water after sterilization (T2 was selected media for cultivation of Oscillatoria sp and Phormedium sp. However, T1 media (waste water without treatment was the promising media for cultivation of Nostoc humifusum. The biodiesel produced from algal species cultivated in waste water media ranged from 3.8 to 11.80% when compared with the conventional method (3.90 to 12.52%. The results of this study suggest that growing algae in nutrient rich media offers a new option of applying algal process in ZWWTP to mange the nutrient load for growth and valuable biodiesel feedstock production.

  1. Cultivating Microalgae in Domestic Wastewater for Biodiesel Production

    Directory of Open Access Journals (Sweden)

    Soha S.M. MOSTAFA

    2012-02-01

    Full Text Available The objective of this study was to evaluate the growth of nine species of microalgae (green and blue green microalgae on domestic waste water samples obtained from Zenein Waste Water Treatment Plant (ZWWTP, Giza governorate, Egypt. The species were cultivated in different kind of waste water; before treatment; after sterilization; with nutrients with sterilization and with nutrients without sterilization. The experiment was conducted in triplicate and cultures were incubated at 251C under continuous shaking (150 rpm and illumination (2000 Lux for 15 days. pH, electric conductivity (EC, optical density (OD , dry weight (DW, were done at the time of incubation and at the end of experiment, in addition to determine the percentage of lipid and biodiesel. The data revealed that, domestic waste water with nutrient media (T3 was promising for cultivation of five algal species when compared with conventional media, Moreover, domestic waste water after sterilization (T2 was selected media for cultivation of Oscillatoria sp and Phormedium sp. However, T1 media (waste water without treatment was the promising media for cultivation of Nostoc humifusum. The biodiesel produced from algal species cultivated in waste water media ranged from 3.8 to 11.80% when compared with the conventional method (3.90 to 12.52%. The results of this study suggest that growing algae in nutrient rich media offers a new option of applying algal process in ZWWTP to mange the nutrient load for growth and valuable biodiesel feedstock production.

  2. PHYSIOLOGICAL STRAIN AMONG WOMEN POTATO CULTIVATORS IN WEST BENGAL, INDIA.

    Science.gov (United States)

    Pal, Amitava; De, Sujaya; Sengupta, Piyali; Maity, Payel; Mahata, Hiranmoy; Shaikh, Saijuddin; Dhara, Prakash C

    2015-12-01

    The present study was aimed to evaluate physiological strain among women cultivators engaged in potato cultivation. The cross-sectional descriptive study was conducted on 150 women participants in different districts of West Bengal State, India. The physiological strain was evaluated by working heart rate, blood lactate and oxygen consumption. The average working heart rate was 109.97 ± 9.94 beats/min when all tasks were considered together. According to the working heart rate, oxygen consumption and energy cost, the potato cultivation job was categorized as a moderate work category. Whereas, according to cardiovascular stress index (CSI), all tasks of potato cultivation were categorized into a stressful category. The more experienced workers were more productive than their less experienced counterparts, and this increased productivity appeared to be a combination of greater efficiency and greater physical exertion. Stepwise multiple linear regression analyses revealed that work pace and work experience had significant association with all the indices of physiological strain. Work pace had strongest significant impact on these indices even after controlling the effect of age, work experience and efficiency. It was concluded that during performing potato cultivation tasks the workers had a great extent of physiological strain.

  3. Membrane technology in microalgae cultivation and harvesting: a review.

    Science.gov (United States)

    Bilad, M R; Arafat, Hassan A; Vankelecom, Ivo F J

    2014-11-15

    Membrane processes have long been applied in different stages of microalgae cultivation and processing. These processes include microfiltration, ultrafiltration, dialysis, forward osmosis, membrane contactors and membrane spargers. They are implemented in many combinations, both as a standalone and as a coupled system (in membrane biomass retention photobioreactors (BR-MPBRs) or membrane carbonation photobioreactors (C-MPBRs). To provide sufficient background on these applications, an overview of membrane materials and membrane processes of interest in microalgae cultivation and processing is provided in this work first. Afterwards, discussion about specific aspects of membrane applications in microbial cultivation and harvesting is provided, including membrane fouling. Many of the membrane processes were shown to be promising options in microalgae cultivation. Yet, significant process optimizations are still required when they are applied to enable microalgae biomass bulk production to become competitive as a raw material for biofuel production. Recent developments of the coupled systems (BR-MPBR and C-MPBR) bring significant promises to improve the volumetric productivity of a cultivation system and the efficiency of inorganic carbon capture, respectively. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Effect of Cultivation on Soil Organic Matter and Aggregate Stability

    Institute of Scientific and Technical Information of China (English)

    A.WILLIAMS; XING Bao-Shan; P.VENEMAN

    2005-01-01

    Agricultural sustainability relates directly to maintaining or enhancing soil quality. Soil quality studies in Canada during the 1980's showed that loss of soil organic matter (SOM) and soil aggregate stability was standard features of non-sustainable land management in agroecosystems. In this study total soil organic carbon (SOC), particulate organic matter (POM), POM-C as a percentage of total SOC, and aggregate stability were determined for three cultivated fields and three adjacent grassland fields to assess the impact of conventional agricultural management on soil quality. POM was investigated using solid-state 13C nuclear magnetic resonance (NMR) to determine any qualitative differences that may be attributed to cultivation. Results show a highly significant loss in total SOC, POM and aggregate stability in the cultivated fields as compared to the grassland fields and a significant loss of POM-C as a percentage of total SOC.Integrated results of the NMR spectra of the POM show a loss in carbohydrate-C and an increase in aromatic-C in the cultivated fields, which translates to a loss of biological lability in the organic matter. Conventional cultivation decreased the quantity and quality of SOM and caused a loss in aggregate stability resulting in an overall decline in soil quality.

  5. Using laser to measure stem thickness and cut weed stems

    DEFF Research Database (Denmark)

    Heisel, T.; Schou, Jørgen; Andreasen, C.

    2002-01-01

    Stem thickness of the weed Solanum nigrum and the crop sugarbeet was determined with a He-Ne laser using a novel non-destructive technique measuring stem shadow. Thereafter, the stems were cut close to the soil surface with a CO2 laser. Treatments were carried out on pot plants, grown...... in the greenhouse, at two different growth stages, and plant dry matter was measured 2-5 weeks after treatment. The relationship between plant dry weight and laser energy was analysed using two different non-linear dose-response regression models; one model included stem thickness as a variable, the other did not....... A binary model was also tested. The non-linear model incorporating stem thickness described the data best, indicating that it would be possible to optimize laser cutting by measuring stem thickness before cutting. The general tendency was that more energy was needed the thicker the stem. Energy uses...

  6. A Problem with STEM

    Science.gov (United States)

    Marder, Michael

    2013-01-01

    Striking differences between physics and biology have important implications for interdisciplinary science, technology, engineering, and mathematics (STEM) education. The author is a physicist with interdisciplinary connections. The research group in which he works, the Center for Nonlinear Dynamics at the University of Texas at Austin, is…

  7. Stem cell heterogeneity revealed

    DEFF Research Database (Denmark)

    Andersen, Marianne S; Jensen, Kim B

    2016-01-01

    The skin forms a protective, water-impermeable barrier consisting of heavily crosslinked epithelial cells. However, the specific role of stem cells in sustaining this barrier remains a contentious issue. A detailed analysis of the interfollicular epidermis now proposes a model for how a composite...... of cells with different properties are involved in its maintenance....

  8. Porcine embryonic stem cells

    DEFF Research Database (Denmark)

    Hall, Vanessa Jane

    2008-01-01

    The development of porcine embryonic stem cell lines (pESC) has received renewed interest given the advances being made in the production of immunocompatible transgenic pigs. However, difficulties are evident in the production of pESCs in-vitro. This may largely be attributable to differences...

  9. STEM Sense and Nonsense

    Science.gov (United States)

    Charette, Robert N.

    2015-01-01

    If you can believe the daily flood of mass media stories, journal articles, and white papers, the United States is facing a STEM worker crisis. Business leaders and politicians warn that the nation is falling hopelessly behind in the global economic race because our students are unprepared for and uninterested in science, technology, engineering,…

  10. Advancing Diversity in STEM

    Science.gov (United States)

    Hill, Paul L.; Shaw, Rose A.; Taylor, Jan R.; Hallar, Brittan L.

    2011-01-01

    Although progress has been made, greater efforts are needed to promote faculty diversity at the college and university levels, especially in STEM fields. Thus, it is important to elucidate best practices both for increasing awareness of diversity issues pertaining to higher education and for implementing change. This article focuses on the…

  11. Integrated STEM Assessment Model

    Science.gov (United States)

    Bicer, Ali; Capraro, Robert M.; Capraro, Mary M.

    2017-01-01

    Previous research identified a strong correlation between mathematics and science performance albeit for small samples of students. Even though there was a high correlation between mathematics and science performance, researchers examining students' STEM achievement investigated mathematics and science achievement separately. The present study…

  12. NASA Applied Sciences' DEVELOP National Program: a unique model cultivating capacity in the geosciences

    Science.gov (United States)

    Ross, K. W.; Favors, J. E.; Childs-Gleason, L. M.; Ruiz, M. L.; Rogers, L.; Allsbrook, K. N.

    2013-12-01

    The NASA DEVELOP National Program takes a unique approach to cultivating the next generation of geoscientists through interdisciplinary research projects that address environmental and public policy issues through the application of NASA Earth observations. Competitively selected teams of students, recent graduates, and early career professionals take ownership of project proposals outlining basic application concepts and have ten weeks to research core scientific challenges, engage partners and end-users, demonstrate prototypical solutions, and finalize and document their results and outcomes. In this high pressure, results-driven environment emerging geoscience professionals build strong networks, hone effective communication skills, and learn how to call on the varied strengths of a multidisciplinary team to achieve difficult objectives. The DEVELOP approach to workforce development has a variety of advantages over classic apprenticeship-style internship systems. Foremost is the experiential learning of grappling with real-world applied science challenges as a primary actor instead of as an observer or minor player. DEVELOP participants gain experience that fosters personal strengths and service to others, promoting a balance of leadership and teamwork in order to successfully address community needs. The program also advances understanding of Earth science data and technology amongst participants and partner organizations to cultivate skills in managing schedules, risks and resources to best optimize outcomes. Individuals who come through the program gain experience and networking opportunities working within NASA and partner organizations that other internship and academic activities cannot replicate providing not only skill development but an introduction to future STEM-related career paths. With the competitive nature and growing societal role of science and technology in today's global community, DEVELOP fosters collaboration and advances environmental

  13. {sup 137}Cs and {sup 9}Sr uptake by sunflower cultivated under hydroponic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Soudek, Petr [Department of Plant Tissue Cultures, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, CZ-166 10 Prague 6 (Czech Republic); Valenova, Sarka [Department of Plant Tissue Cultures, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, CZ-166 10 Prague 6 (Czech Republic); Vavrikova, Zuzana [Department of Plant Tissue Cultures, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, CZ-166 10 Prague 6 (Czech Republic); Vanek, Tomas [Department of Plant Tissue Cultures, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, CZ-166 10 Prague 6 (Czech Republic)]. E-mail: vanek@uochb.cas.cz

    2006-07-01

    The {sup 9}Sr and {sup 137}Cs uptake by the plant Helianthus annuus L. was studied during cultivation in a hydroponic medium. The accumulation of radioactivity in plants was measured after 2, 4, 8, 16 and 32 days of cultivation. About 12% of {sup 137}Cs and 20% of {sup 9}Sr accumulated during the experiments. We did not find any differences between the uptake of radioactive and stable caesium and strontium isotopes. Radioactivity distribution within the plant was determined by autoradiography. {sup 137}Cs was present mainly in nodal segments, leaf veins and young leaves. High activity of {sup 9}Sr was localized in leaf veins, stem, central root and stomata. The influence of stable elements or analogues on the transfer behaviour was investigated. The percentage of non-active caesium and strontium concentration in plants decreased with the increasing initial concentration of Cs or Sr in the medium. The percentage of {sup 9}Sr activity in plants decreased with increasing initial activity of the nuclide in the medium, but the activity of {sup 137}Cs in plants increased. The influence of K{sup +} and NH{sub 4} {sup +} on the uptake of {sup 137}Cs and the influence of Ca{sup 2+} on the uptake of {sup 9}Sr was tested. The highest accumulation of {sup 137}Cs (24-27% of the initial activity of {sup 137}Cs) was found in the presence of 10 mM potassium and 12 mM ammonium ions. Accumulation of about 22% of initial activity of {sup 9}Sr was determined in plants grown on the medium with 8 mM calcium ions.

  14. Estudo prospectivo comparativo de duas técnicas cirúrgicas de extração extra-capsular planejada de catarata com implante de lente intra-ocular: incisão limbar e incisão escleral tunelizada Prospective comparative study of two techniques of planned extracapsular cataract extraction: limbal incision and scleral tunnel incision

    Directory of Open Access Journals (Sweden)

    Lincoln Lemes Freitas

    2001-06-01

    extraction (ECCE with posterior chamber intraocular lens implantation. This study aims to compare limbal incision and scleral tunnel incision in planned ECCE. Methods: Fifty-four consecutive patients (59 eyes with follow-up of 6 months were studied prospectively. ECCE with limbal incision was performed in 30 patients (Group I, and with scleral tunnel incision in 29 patients (Group II. Corrected visual acuity, intraocular inflammation (cells and flare, surgical time, specular microscopy, induced astigmatism and pachymetry were assessed. Results: Surgical time, endothelial cells loss and induced astigmatism were statistically greater in group I than in group II. No significant differences were found between groups when comparing the corrected visual acuity, intraocular inflammation and pachymetry. Conclusions: ECCE with scleral tunnel incision technique offers advantages regarding surgical time, endothelial cells loss and induced astigmatism if compared with limbal incision technique. Surgical steps used in this technique help in transition for phacoemulsification with low cost and a safer way.

  15. Epithelial and mesenchymal stem cells from the umbilical cord lining membrane.

    Science.gov (United States)

    Lim, Ivor J; Phan, Toan Thang

    2014-01-01

    Intense scientific research over the past two decades has yielded much knowledge about embryonic stem cells, mesenchymal stem cells from bone marrow, as well as epithelial stem cells from the skin and cornea. However, the billions of dollars spent in this research have not overcome the fundamental difficulties intrinsic to these stem cell strains related to ethics (embryonic stem cells), as well as to technical issues such as accessibility, ease of cell selection and cultivation, and expansion/mass production, while maintaining consistency of cell stemness (all of the stem cell strains already mentioned). Overcoming these technical hurdles has made stem cell technology expensive and any potential translational products unaffordable for most patients. Commercialization efforts have been rendered unfeasible by this high cost. Advanced biomedical research is on the rise in Asia, and new innovations have started to overcome these challenges. The Nobel Prize-winning Japanese development of iPSCs has effectively introduced a possible replacement for embryonic stem cells. For non-embryonic stem cells, cord lining stem cells (CLSCs) have overcome the preexisting difficulties inherent to mesenchymal stem cells from the bone marrow as well as epithelial stem cells from the skin and cornea, offering a realistic, practical, and affordable alternative for tissue repair and regeneration. This novel CLSC technology was developed in Singapore in 2004 and has 22 international patents granted to date, including those from the US and UK. CLSCs are derived from the umbilical cord outer lining membrane (usually regarded as medical waste) and is therefore free from ethical dilemmas related to its collection. The large quantity of umbilical cord lining membrane that can be collected translates to billions of stem cells that can be grown in primary stem cell culture and therefore very rapid and inexpensive cell cultivation and expansion for clinical translational therapies. Both

  16. Inflammation and cancer stem cells.

    Science.gov (United States)

    Shigdar, Sarah; Li, Yong; Bhattacharya, Santanu; O'Connor, Michael; Pu, Chunwen; Lin, Jia; Wang, Tao; Xiang, Dongxi; Kong, Lingxue; Wei, Ming Q; Zhu, Yimin; Zhou, Shufeng; Duan, Wei

    2014-04-10

    Cancer stem cells are becoming recognised as being responsible for metastasis and treatment resistance. The complex cellular and molecular network that regulates cancer stem cells and the role that inflammation plays in cancer progression are slowly being elucidated. Cytokines, secreted by tumour associated immune cells, activate the necessary pathways required by cancer stem cells to facilitate cancer stem cells progressing through the epithelial-mesenchymal transition and migrating to distant sites. Once in situ, these cancer stem cells can secrete their own attractants, thus providing an environment whereby these cells can continue to propagate the tumour in a secondary niche.

  17. Gravitropism in Leafy Dicot Stems

    Science.gov (United States)

    Salisbury, F. B.

    1985-01-01

    A polarizing research microscope with rotating stage and associated camera equipment were ordered, and techniques of fixation and preparation of specimens were perfected for studying possible changes in orientation of cellulose microfibrils in cell walls of gravistimulated dicot stems. Acid ethephon solutions or acid without ethephon caused elongation of stem tissues where they were applied; stems bent away from the side of application. Acid solutions applied to the bottom of horizontal stems greatly delayed bending. Research in tissue sensitivity changes during gravitropic bending of soybean hypocotyls while immersed in auxin and in castor bean stems is also reported.

  18. Effects of auxin and boron on the rooting of Laurus nobilis L. stem cuttings

    Directory of Open Access Journals (Sweden)

    Fernando Perez Leal

    2004-05-01

    Full Text Available The purpose of this study was to evaluate the effect of indolebutyric acid (IBA, applied with or without boric acid, on rooting laurel (Laurus nobilis L. stem cuttings. The cuttings (15cm that presented two apical leaves were collected from the apexes. They were treated with IBA 0, 50, 150 and 300 mg L-1, with or without boron 150 mg mL-1, for 24 hours. After the treatments, the cuttings were cultivated in polystyrene trays with carbonized rice linings and maintained under intermittent nebulization for 70 days when the percentages for rooting, stem cuttings with callus, and live and dead cuttings, root numbers and root lengths were evaluated. The results showed that IBA 50 mg L-1, IBA 150 and 300mg L-1 with boron enhanced the rooting percentage. The treatment with IBA 150 mg L-1 showed the highest root number in stem cuttings.

  19. Ophthalmology case

    Directory of Open Access Journals (Sweden)

    Fábio Barroso

    2017-07-01

    Discussion: The diagnosis of limbal dermoids is established by the presence of a yellow/white solid tumour located at the limbus. These lesions have been classified into three grades. The treatment for grade I pediatric limbal dermoids is initially conservative. In stages II and III, a combination of simple excision, lamellar keratoplasty, sutureless amniotic membrane and limbal stem cell tranplantation may be necessary. Prognosis is generally favourable.

  20. Cultivation of Communicative Space: Polemical Eloquence vs. Epideictic Eloquence

    Directory of Open Access Journals (Sweden)

    Георгий Георгиевич Хазагеров

    2017-12-01

    Full Text Available The article focuses on the problem of the influence of rhetorical genres of cultivating communication. This influence varies polemical and epideictic genres. The first affect the cultivation of horizontal social relations. Second on the - on the development of vertical ones. Epideictic kind of eloquence interpreted expanded. This takes into account those new genres, which could not have known Aristotle defined the function epideictic speeches as “praise or blame”. It is about propaganda, advertising, homiletics and didactics. At the same time the controversy is associated not only with the dialogic, but also with the monological texts. This raises the question about the role of literature in the cultivation of controversy. The material is mainly the history of Russian literature and language. The conclusion is that the excessive development of some sorts of eloquence at the expense of others can be counter-productive for the culture.

  1. The art of cultivation (på kinesisk)

    DEFF Research Database (Denmark)

    Hauxner, Malene

    2007-01-01

    different ways of cultivating the earth - for plants or for animals, as a farmer or as a shepherd. In its manmade form the language talks about initiative, growth, innovation, control and action. In its untouched, apparently natural form it talks about self-regulation, balance, ripeness and existence...... All art forms have their own language. As music has its sound language, ballet has its step language and film has its film language, landscape architecture also has its specific language. As an art of cultivation it has two, which I call an agricultural and a pastoral language corresponding to two....... The significance in the first interpretation lies in what you do, in the construction and in the second in what you are or in the essence. If we assume that the language of art can be used to understand and deal with ideas of a society, much can be taken from the language of the art of cultivation. It talks about...

  2. A mini review: photobioreactors for large scale algal cultivation.

    Science.gov (United States)

    Gupta, Prabuddha L; Lee, Seung-Mok; Choi, Hee-Jeong

    2015-09-01

    Microalgae cultivation has gained much interest in terms of the production of foods, biofuels, and bioactive compounds and offers a great potential option for cleaning the environment through CO2 sequestration and wastewater treatment. Although open pond cultivation is most affordable option, there tends to be insufficient control on growth conditions and the risk of contamination. In contrast, while providing minimal risk of contamination, closed photobioreactors offer better control on culture conditions, such as: CO2 supply, water supply, optimal temperatures, efficient exposure to light, culture density, pH levels, and mixing rates. For a large scale production of biomass, efficient photobioreactors are required. This review paper describes general design considerations pertaining to photobioreactor systems, in order to cultivate microalgae for biomass production. It also discusses the current challenges in designing of photobioreactors for the production of low-cost biomass.

  3. Hybrids between wild and cultivated carrots in Danish carrot fields

    DEFF Research Database (Denmark)

    Hauser, Thure Pavlo; Bjørn, G. K.

    2001-01-01

    It is well known that wild carrots may pollute the seed crops of cultivated carrots, but whether cultivated carrots can also disperse pollen and seed, and thereby introduce genes into wild carrot populations, is only little described. In Denmark, there is no commercial seed production of carrots...... seeds. Pollen and seed dispersal from fields into wild carrot populations is probably rather frequent in Denmark. A closer inspection of the morphology of flowering plants indicate that some of these (2-60%) are bolters of pure cultivar origin, as indicated primarily by orange root colour. The remainder...... is probably first or advanced generation hybrids between wild and cultivated plants, as indicated by their white roots and combinations of morphological characters from either plant type. Some of these hybrids are imported to Denmark together with the sowing seed, as indicated by significantly different...

  4. Mapping cultivable land from satellite imagery with clustering algorithms

    Science.gov (United States)

    Arango, R. B.; Campos, A. M.; Combarro, E. F.; Canas, E. R.; Díaz, I.

    2016-07-01

    Open data satellite imagery provides valuable data for the planning and decision-making processes related with environmental domains. Specifically, agriculture uses remote sensing in a wide range of services, ranging from monitoring the health of the crops to forecasting the spread of crop diseases. In particular, this paper focuses on a methodology for the automatic delimitation of cultivable land by means of machine learning algorithms and satellite data. The method uses a partition clustering algorithm called Partitioning Around Medoids and considers the quality of the clusters obtained for each satellite band in order to evaluate which one better identifies cultivable land. The proposed method was tested with vineyards using as input the spectral and thermal bands of the Landsat 8 satellite. The experimental results show the great potential of this method for cultivable land monitoring from remote-sensed multispectral imagery.

  5. America's red gold: multiple lineages of cultivated cochineal in Mexico.

    Science.gov (United States)

    Campana, Michael G; Robles García, Nelly M; Tuross, Noreen

    2015-02-01

    Cultivated cochineal (Dactylopius coccus) produces carminic acid, a valuable red dye used to color textiles, cosmetics, and food. Extant native D. coccus is largely restricted to two populations in the Mexican and the Andean highlands, although the insect's ultimate center of domestication remains unclear. Moreover, due to Mexican D. coccus cultivation's near demise during the 19th century, the genetic diversity of current cochineal stock is unknown. Through genomic sequencing, we identified two divergent D. coccus populations in highland Mexico: one unique to Mexico and another that was more closely related to extant Andean cochineal. Relic diversity is preserved in the crops of small-scale Mexican cochineal farmers. Conversely, larger-scale commercial producers are cultivating the Andean-like cochineal, which may reflect clandestine 20th century importation.

  6. America's red gold: multiple lineages of cultivated cochineal in Mexico

    Science.gov (United States)

    Campana, Michael G; Robles García, Nelly M; Tuross, Noreen

    2015-01-01

    Cultivated cochineal (Dactylopius coccus) produces carminic acid, a valuable red dye used to color textiles, cosmetics, and food. Extant native D. coccus is largely restricted to two populations in the Mexican and the Andean highlands, although the insect's ultimate center of domestication remains unclear. Moreover, due to Mexican D. coccus cultivation's near demise during the 19th century, the genetic diversity of current cochineal stock is unknown. Through genomic sequencing, we identified two divergent D. coccus populations in highland Mexico: one unique to Mexico and another that was more closely related to extant Andean cochineal. Relic diversity is preserved in the crops of small-scale Mexican cochineal farmers. Conversely, larger-scale commercial producers are cultivating the Andean-like cochineal, which may reflect clandestine 20th century importation. PMID:25691985

  7. Seaweed cultivation on the Southern and Southeastern Brazilian Coast

    Directory of Open Access Journals (Sweden)

    Franciane Pellizzari

    2011-04-01

    Full Text Available Seaweeds are used directly as food or applied indirectly as texturing agents with gelling and thickening properties (carrageenan, agar and alginates in many industries. They can also be used as fertilizers, animal feed, biomass for fuel, cosmetics and a source of pharmaceuticals, among other applications. The aquaculture of macroalgae is an alternative for producing raw material. Brazil has a coastline with numerous locations suitable for this endeavor. However, despite the known economical and social relevance of seaweed cultivation, Brazilians do not have tradition of using edible seaweeds. In general, the raw material for indirect use (e.g., as a texturing agent is imported. Consequently, seaweed aquaculture is still incipient in Brazil. This contribution presents data and information about macroalgae cultivation on commercial and experimental scales performed on the Southern and Southeastern Brazilian Coastline, as well as a brief overview of research related to some species cultivated in the last decade.

  8. Engineering the path to higher-order thinking in elementary education: A problem-based learning approach for STEM integration

    Science.gov (United States)

    Rehmat, Abeera Parvaiz

    As we progress into the 21st century, higher-order thinking skills and achievement in science and math are essential to meet the educational requirement of STEM careers. Educators need to think of innovative ways to engage and prepare students for current and future challenges while cultivating an interest among students in STEM disciplines. An instructional pedagogy that can capture students' attention, support interdisciplinary STEM practices, and foster higher-order thinking skills is problem-based learning. Problem-based learning embedded in the social constructivist view of teaching and learning (Savery & Duffy, 1995) promotes self-regulated learning that is enhanced through exploration, cooperative social activity, and discourse (Fosnot, 1996). This quasi-experimental mixed methods study was conducted with 98 fourth grade students. The study utilized STEM content assessments, a standardized critical thinking test, STEM attitude survey, PBL questionnaire, and field notes from classroom observations to investigate the impact of problem-based learning on students' content knowledge, critical thinking, and their attitude towards STEM. Subsequently, it explored students' experiences of STEM integration in a PBL environment. The quantitative results revealed a significant difference between groups in regards to their content knowledge, critical thinking skills, and STEM attitude. From the qualitative results, three themes emerged: learning approaches, increased interaction, and design and engineering implementation. From the overall data set, students described the PBL environment to be highly interactive that prompted them to employ multiple approaches, including design and engineering to solve the problem.

  9. Stem cells and transplant arteriosclerosis.

    Science.gov (United States)

    Xu, Qingbo

    2008-05-09

    Stem cells can differentiate into a variety of cells to replace dead cells or to repair damaged tissues. Recent evidence indicates that stem cells are involved in the pathogenesis of transplant arteriosclerosis, an alloimmune initiated vascular stenosis that often results in transplant organ failure. Although the pathogenesis of transplant arteriosclerosis is not yet fully understood, recent developments in stem cell research have suggested novel mechanisms of vascular remodeling in allografts. For example, stem cells derived from the recipient may repair damaged endothelial cells of arteries in transplant organs. Further evidence suggests that stem cells or endothelial progenitor cells may be released from both bone marrow and non-bone marrow tissues. Vascular stem cells appear to replenish cells that died in donor vessels. Concomitantly, stem/progenitor cells may also accumulate in the intima, where they differentiate into smooth muscle cells. However, several issues concerning the contribution of stem cells to the pathogenesis of transplant arteriosclerosis are controversial, eg, whether bone marrow-derived stem cells can differentiate into smooth muscle cells that form neointimal lesions of the vessel wall. This review summarizes recent research on the role of stem cells in transplant arteriosclerosis, discusses the mechanisms of stem cell homing and differentiation into mature endothelial and smooth muscle cells, and highlights the controversial issues in the field.

  10. Anti-oxidant properties and polyphenolic profile screening of Vitis vinifera stems and leaves crude extracts grown in Perlis, Malaysia

    Science.gov (United States)

    Zakaria, Nursyahda; Zulkifli, Razauden Mohamed; Akhir, Fazrena Nadia Md; Basar, Norazah

    2014-03-01

    Grape has become a fast growing agricultural sector in Malaysia producing between 0.62 kg to 2.03 kg waste per vinestock. This study aims to generate useful information on anti-oxidative properties as well as polyphenolic composition of grapevine waste. Stems and leaves of Vitis vinifera cultivated in Perlis, Malaysia were extracted using methanol, ethyl acetate and petroleum ether. Ethyl acetate stems extract exhibited highest total phenolic content. While in DPPH assay, methanolic stems extract show the highest antioxidant activities. This result indicates that total phenolic content in the extracts may not contribute directly to the antioxidant activities. Thin Layer Chromatograms of all crude extracts exhibited good separation under solvent system petroleum ether-ethyl acetate (2:3) resulted in detection of resveratrol in ethyl acetate stems crude extract.

  11. Materials as stem cell regulators

    Science.gov (United States)

    Murphy, William L.; McDevitt, Todd C.; Engler, Adam J.

    2014-06-01

    The stem cell/material interface is a complex, dynamic microenvironment in which the cell and the material cooperatively dictate one another's fate: the cell by remodelling its surroundings, and the material through its inherent properties (such as adhesivity, stiffness, nanostructure or degradability). Stem cells in contact with materials are able to sense their properties, integrate cues via signal propagation and ultimately translate parallel signalling information into cell fate decisions. However, discovering the mechanisms by which stem cells respond to inherent material characteristics is challenging because of the highly complex, multicomponent signalling milieu present in the stem cell environment. In this Review, we discuss recent evidence that shows that inherent material properties may be engineered to dictate stem cell fate decisions, and overview a subset of the operative signal transduction mechanisms that have begun to emerge. Further developments in stem cell engineering and mechanotransduction are poised to have substantial implications for stem cell biology and regenerative medicine.

  12. Growth and anaerobic digestion characteristics of microalgae cultivated using various types of sewage.

    Science.gov (United States)

    Hidaka, Taira; Inoue, Kenichiro; Suzuki, Yutaka; Tsumori, Jun

    2014-10-01

    Microalgal cultivation combined with anaerobic digestion at wastewater treatment plants is promising to recover energy. This study investigated the growth and anaerobic digestion characteristics of microalgae cultivated using nutrients in sewage. Microalgae were cultivated using primary effluent, secondary effluent, and dewatering filtrate. Microscopic observation indicated that Chlorella was cultivated using dewatering filtrate of anaerobic digestion without controlling the type of species. Batch anaerobic digestion experiments with digested sludge showed that the methane conversion ratio of the cultivated mixture was approximately 40-65%. Different cultivation time did not affect the microalgal contents. Methane recovery mass was 0.13NL-methane/L-cultivation liquor. The C/N ratio of the cultivated mixture was approximately 3-5, but the apparent ammonia release ratio was smaller than that of sewage sludge during digestion. These results proved the applicability of methane recovery from microalgae cultivated using nutrients included in anaerobically digested sludge.

  13. Bioreactor systems for tissue engineering II. Strategies for the expansion and directed differentiation of stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Kasper, Cornelia [Hannover Univ. (Germany). Inst. fuer Technische Chemie; Griensven, Martijn van [Ludwig Boltzmann Institut fuer Klinische und Experimentelle Traumatologie, Wien (Austria); Poertner, Ralf (eds.) [Technische Univ. Hamburg-Harburg (Germany). Inst. Biotechnologie und Verfahrenstechnik

    2010-07-01

    Alternative Sources of Adult Stem Cells: Human Amniotic Membrane, by S. Wolbank, M. van Griensven, R. Grillari-Voglauer, and A. Peterbauer-Scherb; - Mesenchymal Stromal Cells Derived from Human Umbilical Cord Tissues: Primitive Cells with Potential for Clinical and Tissue Engineering Applications, by P. Moretti, T. Hatlapatka, D. Marten, A. Lavrentieva, I. Majore, R. Hass and C. Kasper; - Isolation, Characterization, Differentiation, and Application of Adipose-Derived Stem Cells, by J. W. Kuhbier, B. Weyand, C. Radtke, P. M. Vogt, C. Kasper and K. Reimers; - Induced Pluripotent Stem Cells: Characteristics and Perspectives, by T. Cantz and U. Martin; - Induced Pluripotent Stem Cell Technology in Regenerative Medicine and Biology, by D. Pei, J. Xu, Q. Zhuang, H.-F. Tse and M. A. Esteban; - Production Process for Stem Cell Based Therapeutic Implants: Expansion of the Production Cell Line and Cultivation of Encapsulated Cells, by C. Weber, S. Pohl, R. Poertner, P. Pino-Grace, D. Freimark, C. Wallrapp, P. Geigle and P. Czermak; - Cartilage Engineering from Mesenchymal Stem Cells, by C. Goepfert, A. Slobodianski, A.F. Schilling, P. Adamietz and R. Poertner; - Outgrowth Endothelial Cells: Sources, Characteristics and Potential Applications in Tissue Engineering and Regenerative Medicine, by S. Fuchs, E. Dohle, M. Kolbe, C. J. Kirkpatrick; - Basic Science and Clinical Application of Stem Cells in Veterinary Medicine, by I. Ribitsch, J. Burk, U. Delling, C. Geissler, C. Gittel, H. Juelke, W. Brehm; - Bone Marrow Stem Cells in Clinical Application: Harnessing Paracrine Roles and Niche Mechanisms, by R. M. El Backly, R. Cancedda; - Clinical Application of Stem Cells in the Cardiovascular System, C. Stamm, K. Klose, Y.-H. Choi. (orig.)

  14. Hepatogenic differentiation of human mesenchymal stem cells from adipose tissue in comparison with bone marrow mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    Raquel Taléns-Visconti; Ana Bonora; Ramiro Jover; Vicente Mirabet; Francisco Carbonell; José Vicente Castell; María José Gómez-Lechón

    2006-01-01

    AIM: To investigate and compare the hepatogenic transdifferentiation of adipose tissue-derived stem cells (ADSC) and bone marrow-derived mesenchymal stem cells (BMSC) in vitro. Transdifferentiation of BMSC into hepatic cells in vivo has been described. Adipose tissue represents an accessible source of ADSC, with similar characteristics to BMSC.METHODS: BMSCs were obtained from patients undergoing total hip arthroplasty and ADSC from human adipose tissue obtained from lipectomy. Cells were grown in medium containing 15% human serum. Cultures were serum deprived for 2 d before cultivating under similar pro-hepatogenic conditions to those of liver development using a 2-step protocol with sequential addition of growth factors, cytokines and hormones. Hepatic differentiation was RT-PCR-assessed and liver-marker genes were immunohistochemically analysed.RESULTS: BMSC and ADSC exhibited a fibroblastic morphology that changed to a polygonal shape when cells differentiated. Expression of stem cell marker Thy1 decreased in differentiated ADSC and BMSC. However, the expression of the hepatic markers, albumin and CYPs increased to a similar extent in differentiated BMSC and ADSC. Hepatic gene activation could be attributed to increased liver-enriched transcription factors (C/EBPβ and HNF4α), as demonstrated by adenoviral expression vectors.CONCLUSION: Mesenchymal stem cells can be induced to hepatogenic transdifferentiation in vitro. ADSCs have a similar hepatogenic differentiation potential to BMSC,but a longer culture period and higher proliferation capacity. Therefore, adipose tissue may be an ideal source of large amounts of autologous stem cells, and may become an alternative for hepatocyte regeneration, liver cell transplantation or preclinical drug testing.

  15. Valve stem and packing assembly

    Energy Technology Data Exchange (ETDEWEB)

    Wordin, J.J.

    1991-09-03

    A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents over tightening of the retaining nut and the resulting excessive friction between stem and stem packing. 2 figures.

  16. Valve stem and packing assembly

    Energy Technology Data Exchange (ETDEWEB)

    Wordin, John J. (Bingham County, ID)

    1991-01-01

    A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents overtightening of the retaining nut and the resulting excessive friction between stem and stem packing.

  17. Valve stem and packing assembly

    Energy Technology Data Exchange (ETDEWEB)

    Wordin, J.J.

    1990-01-01

    A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents overtightening of the retaining nut and the resulting excessive friction between stem and stem packing.

  18. Differentiation of embryonic versus adult rat neural stem cells into dopaminergic neurons in vitro

    Institute of Scientific and Technical Information of China (English)

    Chunlong Ke; Baili Chen; Shaolei Guo; Chao Yang

    2008-01-01

    BACKGROUND: It has been reported that the conversion of neural stem cells into dopaminergic neurons in vitro can be increased through specific cytokine combinations. Such neural stem cell-derived dopaminergic neurons could be used for the treatment of Parkinson's disease. However, little is known about the differences in dopaminergic differentiation between neural stem cells derived from adult and embryonic rats.OBJECTIVE: To study the ability of rat adult and embryonic-derived neural stem cells to differentiate into dopaminergic neurons in vitro.DESIGN: Randomized grouping design.SETTING: Department of Neurosurgery in the First Affiliated Hospital of Sun Yat-sen University.MATERIALS: This experiment was performed at the Surgical Laboratory in the First Affiliated Hospital of Sun Yat-scn University (Guangzhou, Guangdong, China) from June to December 2007. Eight, adult, male,Sprague Dawley rats and eight, pregnant, Sprague Dawley rats (embryonic day 14 or 15) were provided by the Experimental Animal Center of Sun Yat-sen University.METHODS: Neural stem cells derived from adult and embryonic rats were respectively cultivated in serum-free culture medium containing epidermal growth factor and basic fibroblast growth factor. After passaging, neural stem cells were differentiated in medium containing interleukin-1 ct, interleukin-11, human leukemia inhibition factor, and glial cell line-derived neurotrophic factor. Six days later, cells were analyzed by immunocytochemistry and flow cytometry.MAIN OUTCOME MEASURES: Alterations in cellular morphology after differentiation of neural stem cells derived from adult and embryonic rats; and percentage of tyrosine hydroxylase-positive neurons in the differentiated cells.RESULTS: Neural stem cells derived from adult and embryonic rats were cultivated in differentiation medium. Six days later, differentiated cells were immunoreactive for tyrosine hydroxylasc. The percentage of tyrosine hydroxylase positive neurons was (5.6 ± 2

  19. Early steps of adventitious rooting: morphology, hormonal profiling and carbohydrate turnover in carnation stem cuttings.

    Science.gov (United States)

    Agulló-Antón, María Ángeles; Ferrández-Ayela, Almudena; Fernández-García, Nieves; Nicolás, Carlos; Albacete, Alfonso; Pérez-Alfocea, Francisco; Sánchez-Bravo, José; Pérez-Pérez, José Manuel; Acosta, Manuel

    2014-03-01

    The rooting of stem cuttings is a common vegetative propagation practice in many ornamental species. A detailed analysis of the morphological changes occurring in the basal region of cultivated carnation cuttings during the early stages of adventitious rooting was carried out and the physiological modifications induced by exogenous auxin application were studied. To this end, the endogenous concentrations of five major classes of plant hormones [auxin, cytokinin (CK), abscisic acid, salicylic acid (SA) and jasmonic acid] and the ethylene precursor 1-aminocyclopropane-1-carboxylic acid were analyzed at the base of stem cuttings and at different stages of adventitious root formation. We found that the stimulus triggering the initiation of adventitious root formation occurred during the first hours after their excision from the donor plant, due to the breakdown of the vascular continuum that induces auxin accumulation near the wounding. Although this stimulus was independent of exogenously applied auxin, it was observed that the auxin treatment accelerated cell division in the cambium and increased the sucrolytic activities at the base of the stem, both of which contributed to the establishment of the new root primordia at the stem base. Further, several genes involved in auxin transport were upregulated in the stem base either with or without auxin application, while endogenous CK and SA concentrations were specially affected by exogenous auxin application. Taken together our results indicate significant crosstalk between auxin levels, stress hormone homeostasis and sugar availability in the base of the stem cuttings in carnation during the initial steps of adventitious rooting.

  20. Human embryonic stem cells differentiate into functional renal proximal tubular-like cells.

    Science.gov (United States)

    Narayanan, Karthikeyan; Schumacher, Karl M; Tasnim, Farah; Kandasamy, Karthikeyan; Schumacher, Annegret; Ni, Ming; Gao, Shujun; Gopalan, Began; Zink, Daniele; Ying, Jackie Y

    2013-04-01

    Renal cells are used in basic research, disease models, tissue engineering, drug screening, and in vitro toxicology. In order to provide a reliable source of human renal cells, we developed a protocol for the differentiation of human embryonic stem cells into renal epithelial cells. The differentiated stem cells expressed markers characteristic of renal proximal tubular cells and their precursors, whereas markers of other renal cell types were not expressed or expressed at low levels. Marker expression patterns of these differentiated stem cells and in vitro cultivated primary human renal proximal tubular cells were comparable. The differentiated stem cells showed morphological and functional characteristics of renal proximal tubular cells, and generated tubular structures in vitro and in vivo. In addition, the differentiated stem cells contributed in organ cultures for the formation of simple epithelia in the kidney cortex. Bioreactor experiments showed that these cells retained their functional characteristics under conditions as applied in bioartificial kidneys. Thus, our results show that human embryonic stem cells can differentiate into renal proximal tubular-like cells. Our approach would provide a source for human renal proximal tubular cells that are not affected by problems associated with immortalized cell lines or primary cells.