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Yang B, Zhao Z, Pan Y, Xie J, Zhou B, Li Y, Dong Y, Liu D. Shear-Thinning and Designable Responsive Supramolecular DNA Hydrogels Based on Chemically Branched DNA. ACS Appl Mater Interfaces 2021; 13:48414-48422. [PMID: 34633793 DOI: 10.1021/acsami.1c15494] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A novel supramolecular DNA hydrogel system was designed based on a directly synthesized chemically branched DNA. For the hydrogel formation, a self-dimer DNA with two sticky ends was designed as the linker to induce the gelation of B-Y. By programing the linker sequence, thermal and metal-ion responsiveness could be introduced into this hydrogel system. This supramolecular DNA hydrogel shows shear-thinning, designable responsiveness, and good biocompatibility, which will simplify the hydrogel composition and preparation process of the supramolecular DNA hydrogel and accelerate its biomedical applications.
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Affiliation(s)
- Bo Yang
- Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Zhihan Zhao
- Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Yufan Pan
- Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Jiayin Xie
- Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Bini Zhou
- Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Yujie Li
- Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Yuanchen Dong
- CAS Key Laboratory of Colloid Interface and Chemical Thermodynamics, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Dongsheng Liu
- Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, China
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Albertini DF. Embryo culture goes back to the future. J Assist Reprod Genet 2021; 37:1767-1768. [PMID: 32785875 DOI: 10.1007/s10815-020-01923-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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McKenzie JA, Barghash RF, Alsaggaf AT, Kulkarni O, Boudreau K, Menard F, Neeland EG, Klegeris A. Synthesis and Evaluation of Novel Pyrazole Ethandiamide Compounds as Inhibitors of Human THP-1 Monocytic Cell Neurotoxicity. Cells 2019; 8:cells8070655. [PMID: 31261948 PMCID: PMC6679371 DOI: 10.3390/cells8070655] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 06/25/2019] [Accepted: 06/27/2019] [Indexed: 12/20/2022] Open
Abstract
Neuroinflammation and microglia-mediated neurotoxicity contribute to the pathogenesis of a broad range of neurodegenerative diseases; therefore, identifying novel compounds that can suppress adverse activation of glia is an important goal. We have previously identified a class of trisubstituted pyrazoles that possess neuroprotective and anti-inflammatory properties. Here, we describe a second generation of pyrazole analogs that were designed to improve their neuroprotective activity toward neurons under inflammatory conditions. Pyrazolyl oxalamide derivatives were designed to explore the effects of steric and electronic factors. Three in vitro assays were performed to evaluate the compounds' anti-neurotoxic, neuroprotective, and cytotoxic activity using human THP-1, PC-3, and SH-SY5Y cells. Five compounds significantly reduced the neurotoxic secretions from immune-stimulated microglia-like human THP-1 monocytic cells. One of these compounds was also found to protect SH-SY5Y neuronal cells when they were exposed to cytotoxic THP-1 cell supernatants. While one of the analogs was discarded due to its interference with the cell viability assay, most compounds were innocuous to the cultured cells at the concentrations used (1-100 μM). The new compounds reported herein provide a design template for the future development of lead candidates as novel inhibitors of neuroinflammation and neuroprotective drugs.
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Affiliation(s)
- Jordan A McKenzie
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, BC V1V 1V7, Canada
| | - Reham F Barghash
- Department of Chemistry, University of British Columbia Okanagan Campus, Kelowna, BC V1V 1V7, Canada
- Chemical Research Industries Division, National Research Centre, Dokki, Giza D-12622, Egypt
| | - Azhaar T Alsaggaf
- Department of Chemistry, University of British Columbia Okanagan Campus, Kelowna, BC V1V 1V7, Canada
- Department of Chemistry, Taibah University, Medina 42353, Saudi Arabia
| | - Omkar Kulkarni
- Department of Chemistry, University of British Columbia Okanagan Campus, Kelowna, BC V1V 1V7, Canada
| | - Kalun Boudreau
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, BC V1V 1V7, Canada
| | - Frederic Menard
- Department of Chemistry, University of British Columbia Okanagan Campus, Kelowna, BC V1V 1V7, Canada.
| | - Edward G Neeland
- Department of Chemistry, University of British Columbia Okanagan Campus, Kelowna, BC V1V 1V7, Canada
| | - Andis Klegeris
- Department of Biology, University of British Columbia Okanagan Campus, Kelowna, BC V1V 1V7, Canada.
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Xue Q, Wang R, Xu W, Wang J, Tan L. The stresses of allelochemicals isolated from culture solution of diatom Phaeodactylum tricornutum Bohlin on growth and physiology of two marine algae. Aquat Toxicol 2018; 205:51-57. [PMID: 30321860 DOI: 10.1016/j.aquatox.2018.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Revised: 10/05/2018] [Accepted: 10/05/2018] [Indexed: 06/08/2023]
Abstract
The allelopathic effects of extracts isolated from the culture filtrate of diatom Phaeodactylum triconutum Bohlin on typical marine microalgae Prorocentrum donghaiense Lu and Dunaliella salina Teodoresco were investigated by determining different physiological and biochemical parameters, such as growth rate, membrane systems and esterase activity under controlled laboratory conditions. The growth of P. donghaiense was significantly inhibited immediately after exposure to the allelochemicals, while the algae density of D. salina was less sensitive. Chlorophyll-a content, membrane systems, as well as esterase activity were simultaneously investigated by flow cytometry with particular fluorescent markers and exhibited changeable sensitivities. The results demonstrated that the membrane systems of P. donghaiense were suppressed by the allelochemicals directly, causing loss of integrity and membrane penetration. Esterase activity was the most sensitive indicator as that of P. donghaiense cells significantly increased in short time and was inhibited subsequently. However, the membrane of D. salina remained intact still after exposure to the extracts and the esterase activity was only inhibited on last day during experiment period. Membrane potential and chlorophyll-a content of the two marine algae also showed somewhat different changes, as that of P. donghaiense cells were impaired after 5 day exposure to all volume conditions while these two characteristics of D. salina was only suppressed by exposure to high volume of the allelochemicals on day 6. The present results indicated that the inhibition of culture filtrate of P. triconutum on P. donghaiense was algicidal whereas the effect on D. salina appeared to be algistatic.
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Affiliation(s)
- Qiaona Xue
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China
| | - Rui Wang
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China
| | - Wenjing Xu
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China
| | - Jiangtao Wang
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
| | - Liju Tan
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China
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Gugliandolo A, Pollastro F, Grassi G, Bramanti P, Mazzon E. In Vitro Model of Neuroinflammation: Efficacy of Cannabigerol, a Non-Psychoactive Cannabinoid. Int J Mol Sci 2018; 19:ijms19071992. [PMID: 29986533 PMCID: PMC6073490 DOI: 10.3390/ijms19071992] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 07/02/2018] [Accepted: 07/06/2018] [Indexed: 12/20/2022] Open
Abstract
Inflammation and oxidative stress play main roles in neurodegeneration. Interestingly, different natural compounds may be able to exert neuroprotective actions against inflammation and oxidative stress, protecting from neuronal cell loss. Among these natural sources, Cannabis sativa represents a reservoir of compounds exerting beneficial properties, including cannabigerol (CBG), whose antioxidant properties have already been demonstrated in macrophages. Here, we aimed to evaluate the ability of CBG to protect NSC-34 motor neurons against the toxicity induced from the medium of LPS-stimulated RAW 264.7 macrophages. Using MTT assay, we observed that CBG pre-treatment was able to reduce the loss of cell viability induced by the medium of LPS-stimulated macrophages in NSC-34 cells. Indeed, CBG pre-treatment inhibited apoptosis, as shown by the reduction of caspase 3 activation and Bax expression, while Bcl-2 levels increased. Furthermore, CBG pre-treatment counteracted not only inflammation, as demonstrated by the reduction of IL-1β, TNF-α, IFN-γ and PPARγ protein levels assessed by immunocytochemistry, but also oxidative stress in NSC-34 cells treated with the medium of LPS-stimulated RAW 264.7. Indeed, immunocytochemistry showed that CBG pre-treatment reduced nitrotyrosine, SOD1 and iNOS protein levels and restored Nrf-2 levels. All together, these results indicated the neuroprotective effects of CBG, that may be a potential treatment against neuroinflammation and oxidative stress.
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Affiliation(s)
| | - Federica Pollastro
- Department of Pharmaceutical Sciences, University of Eastern Piedmont "Amedeo Avogadro", 28100 Novara, Italy.
| | - Gianpaolo Grassi
- Research Centre for Industrial Crops, Council for Agricultural Research and Economics (CREA-CIN), 45100 Rovigo, Italy.
| | | | - Emanuela Mazzon
- IRCCS Centro Neurolesi "Bonino Pulejo", 98124 Messina, Italy.
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Wilkinson AC, Morita M, Nakauchi H, Yamazaki S. Branched-chain amino acid depletion conditions bone marrow for hematopoietic stem cell transplantation avoiding amino acid imbalance-associated toxicity. Exp Hematol 2018; 63:12-16.e1. [PMID: 29705267 PMCID: PMC6052250 DOI: 10.1016/j.exphem.2018.04.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 04/06/2018] [Accepted: 04/18/2018] [Indexed: 01/28/2023]
Abstract
Hematopoietic stem cells (HSCs) are used clinically in bone marrow (BM) transplantation due to their unique ability to reform the entire hematopoietic system. Recently, we reported that HSCs are highly sensitive to valine, one of the three branched-chain amino acids (BCAAs) in addition to isoleucine and leucine. Dietary depletion of valine could even be used as a conditioning regimen for HSC transplantation. Here, we report that HSCs are highly sensitive to the balance of BCAAs, with both proliferation and survival reduced by BCAA imbalance. However, low but balanced BCAA levels failed to rescue HSC maintenance. Importantly, in vivo depletion of all three BCAAs was significantly less toxic than depletion of valine only. We demonstrate that BCAA depletion can replace valine depletion as a safer alternative to BM conditioning. In summary, by determining HSC metabolic requirements, we can improve metabolic approaches to BM conditioning.
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Affiliation(s)
- Adam C Wilkinson
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, USA; Department of Genetics, Stanford University, Stanford, CA, USA; Department of Haematology, University of Cambridge, Cambridge, UK
| | - Maiko Morita
- Division of Stem Cell Therapy, Center for Stem Cell Biology and Regeneration Medicine, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan
| | - Hiromitsu Nakauchi
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, USA; Department of Genetics, Stanford University, Stanford, CA, USA; Division of Stem Cell Therapy, Center for Stem Cell Biology and Regeneration Medicine, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan
| | - Satoshi Yamazaki
- Division of Stem Cell Therapy, Center for Stem Cell Biology and Regeneration Medicine, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan.
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Sharma A, Sharma S, Mittal A, Naik SN. Evidence for the involvement of nematocidal toxins of Purpureocillium lilacinum 6029 cultured on Karanja deoiled cake liquid medium. World J Microbiol Biotechnol 2016; 32:82. [PMID: 27038952 DOI: 10.1007/s11274-016-2038-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 02/25/2016] [Indexed: 11/30/2022]
Abstract
In present study, in vitro nematocidal bioassays, FT-IR and HPLC analysis were employed to demonstrate the involvement of toxins of Purpureocillium lilacinum in killing root-knot nematodes (Meloidogyne incognita). During growth study, maximum mycelial biomass (10.52 g/l) in de-oiled Karanja cake medium was achieved on 8th day while complete mortality of nematodes was obtained by 6th day filtrate (FKSM). Maximum production of crude nematocidal toxin was recorded on 7th day suggesting that the toxin production was paralleled with growth of the fungus. The median lethal concentration (LC50) determined for the crude toxin from 6th day to 10th day ranged from 89.41 to 43.21 ppm. The median lethal time (LT50) for the crude toxin of FKSM was found to be 1.46 h. This is the first report of implementing a comparative infra-red spectroscopy coupled with HPLC analysis to predict the presence of nematocidal toxin in the fungal filtrate cultured on Karanja deoiled cake liquid medium.
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Affiliation(s)
- Abhishek Sharma
- Centre for Rural Development and Technology, Indian Institute of Technology Delhi, 289, Hauz Khas, New Delhi, 110016, India
| | - Satyawati Sharma
- Centre for Rural Development and Technology, Indian Institute of Technology Delhi, 289, Hauz Khas, New Delhi, 110016, India.
| | - Aditya Mittal
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
| | - S N Naik
- Centre for Rural Development and Technology, Indian Institute of Technology Delhi, 289, Hauz Khas, New Delhi, 110016, India
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Tan Y, Peng L, Yuan L, Wang S. [Toxicity of Pythium oligandrum broth to animal and its control effect on rot diseases caused by Penicillium italicum and Penicillium digitatum in orange fruit storage]. Wei Sheng Wu Xue Bao 2015; 55:1418-1426. [PMID: 26915223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
OBJECTIVE In order to develop a safe, nontoxic and efficient biological antistaling agent and to decrease the incidence of rot diseases caused by the Penicillium italicum and Penicillium digitatum in orange fruit storage. METHODS the present experiment was carried out with Pythium oligandrum broth (POB) produced by our self-isolated strain (P. oligandrum CQ2010) to study the toxicity to animal. Thereafter, mycelium growth and spore germination of both P. digitatum and P. italicum and control effect of rot disease in orange storage were compared after treated by liquid culture medium (control), POB, prochloraz (PC) , and PC + POB. RESULTS Gastric lavage with large amount POB did not influence mouse weight. The animals also showed no abnormality in appearance, behaviors and pathology changes in heart, liver, kidney, lung and intestine. POB decreased the hyphal growth by 70.24% - 93.74% and spore germination by 44.91% - 87.82% (24 h after POB addition) of these two pathogenic fungi. Disease incidence of orange fruit following P. italicum inoculation changed in the sequence: CK > POB > PC > PC + POB and the control efficacy behaved otherwise. In commercial simulation storage, the disease incidence of orange fruit caused by P. digitatum and P. italicum was above 50% of the total. The fruit rot rate was 26.40% (CK), 15.03% (POB), 16.61% (PC) and 4.21% (PC + POB). There were no significant differences in fruit quality under different treatments. CONCLUSION POB was safe to animal and could decrease rot disease incidence caused by P. italicum and P. digitatum in orange storage whereby producing a positive interaction with prochloraz and controlling rot diseases caused by these two fungi.
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Leonard PH, Charlesworth MC, Benson L, Walker DL, Fredrickson JR, Morbeck DE. Variability in protein quality used for embryo culture: embryotoxicity of the stabilizer octanoic acid. Fertil Steril 2013; 100:544-9. [PMID: 23602317 DOI: 10.1016/j.fertnstert.2013.03.034] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 03/21/2013] [Accepted: 03/21/2013] [Indexed: 12/22/2022]
Abstract
OBJECTIVE To screen human serum albumin (HSA) preparations for toxicity and investigate causes of variation. DESIGN Experimental laboratory study. SETTING University-based laboratory. ANIMAL(S) FVB and CF1 mice crossed to create embryos used in experiments. INTERVENTION(S) Mouse embryo assay performed with 5% or 15% HSA (100 mg/mL albumin) from three samples from three separate manufacturers (A, B, C). MAIN OUTCOME MEASURE(S) Blastocyst rates calculated at 96 hours of culture (experiments repeated in triplicate). RESULT(S) The HSA preparations were desalted to remove stabilizers added during HSA processing, then mass spectrometry was used to determine the relative variation in stabilizer concentrations; the effect of the stabilizer octanoic acid on embryo development was tested. At 5% HSA, all samples had blastocyst rates ≥ 70%; at 15% HSA, the blastocyst rates for samples B and C were <50%. Desalting did not affect sample B but did improve the blastocyst rates of sample C. Mass spectrometry revealed high levels of octanoic acid in sample C compared with sample A. The addition of octanoic acid to sample A produced toxicity similar to sample C. CONCLUSION(S) The stabilizer octanoic acid varies by lot and inhibits embryo development. Because octanoic acid is known to cause disruptions in mitochondrial bioenergetics, reduce intracellular pH, and induce oxidative damage in peripheral tissues, its use in embryo culture should be monitored and limited.
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Affiliation(s)
- Phoebe H Leonard
- Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, Mayo Clinic, Rochester, Minnesota 55905, USA
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Rathnayake IVN, Megharaj M, Krishnamurti GSR, Bolan NS, Naidu R. Heavy metal toxicity to bacteria - are the existing growth media accurate enough to determine heavy metal toxicity? Chemosphere 2013; 90:1195-200. [PMID: 23040649 DOI: 10.1016/j.chemosphere.2012.09.036] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 07/21/2012] [Accepted: 09/08/2012] [Indexed: 05/08/2023]
Abstract
A new minimal medium was formulated considering the limitations of the existing media for testing heavy metal sensitivity to bacteria. Toxicity of cadmium and copper to three bacteria was investigated in the new medium and compared with three other media commonly used to study the effect of the toxic metals. Based on speciation data arrived at using ion-selective electrodes, the available free-metal concentration in solution was highest in the MES-buffered medium. This finding was strongly supported by the estimated EC(50) values for the metals tested based on the toxicity bioassays. The free-ionic cadmium and copper concentrations in the medium provide more accurate determination of metal concentrations that affects the bacteria, than with most of other existing media. This will avoid doubts on other media and misleading conclusions relevant to the toxicity of heavy metals to bacteria and provides a better option for the study of metal-bacteria interactions.
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Affiliation(s)
- I V N Rathnayake
- Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, South Australia 5095, Australia
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Jelic A, Cruz-Morató C, Marco-Urrea E, Sarrà M, Perez S, Vicent T, Petrović M, Barcelo D. Degradation of carbamazepine by Trametes versicolor in an air pulsed fluidized bed bioreactor and identification of intermediates. Water Res 2012; 46:955-964. [PMID: 22178304 DOI: 10.1016/j.watres.2011.11.063] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2011] [Revised: 11/22/2011] [Accepted: 11/23/2011] [Indexed: 05/31/2023]
Abstract
The paper describes the aerobic degradation of carbamazepine (CBZ), an anti-epileptic drug widely found in aquatic environment, from Erlenmeyer flask to bioreactor by the white-rot fungus Trametes versicolor. In Erlenmeyer flask, CBZ at approximately 9 mg L(-1) was almost completely eliminated (94%) after 6 d, while at near environmentally relevant concentrations of 50 μg L(-1), 61% of the contaminant was degraded in 7 d. Acridone, acridine, 10,11-dihydro-10,11-dihydroxy-CBZ, and 10, 11-epoxy-CBZ were identified as major metabolites, confirming the degradation of CBZ. The degradation process was then carried out in an air pulsed fluidized bioreactor operated in batch and continuous mode. Around 96% of CBZ was removed after 2 days in batch mode operation, and 10,11-dihydro-10,11-epoxycarbamazepine was found as unique metabolite. In bioreactor operated in continuous mode with a hydraulic retention time of 3 d, 54% of the inflow concentration (approx. 200 μg L(-1)) was reduced at the steady state (25 d) with a CBZ degradation rate of 11.9 μg CBZ g(-1) dry weight d(-1). No metabolite was detected in the culture broth. Acute toxicity tests (Microtox) indicated that the final culture broth in both batch and continuous mode operation were non toxic, with 15 min EC50 values of 24% and 77%, respectively.
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Affiliation(s)
- Aleksandra Jelic
- Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA), Spanish Council for Scientific Research (CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain
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Abstract
Neurobasal defined culture medium has been optimized for survival of rat embryonic hippocampal neurons and is now widely used for many types of primary neuronal cell culture. Therefore, we were surprised that routine medium exchange with serum- and supplement-free Neurobasal killed as many as 50% of postnatal hippocampal neurons after a 4 h exposure at day in vitro 12–15. Minimal Essential Medium (MEM), in contrast, produced no significant toxicity. Detectable Neurobasal-induced neuronal death occurred with as little as 5 min exposure, measured 24 h later. D-2-Amino-5-phosphonovalerate (D-APV) completely prevented Neurobasal toxicity, implicating direct or indirect N-methyl-D-aspartate (NMDA) receptor-mediated neuronal excitotoxicity. Whole-cell recordings revealed that Neurobasal but not MEM directly activated D-APV-sensitive currents similar in amplitude to those gated by 1 µM glutamate. We hypothesized that L-cysteine likely mediates the excitotoxic effects of Neurobasal incubation. Although the original published formulation of Neurobasal contained only 10 µM L-cysteine, commercial recipes contain 260 µM, a concentration in the range reported to activate NMDA receptors. Consistent with our hypothesis, 260 µM L-cysteine in bicarbonate-buffered saline gated NMDA receptor currents and produced toxicity equivalent to Neurobasal. Although NMDA receptor-mediated depolarization and Ca2+ influx may support survival of young neurons, NMDA receptor agonist effects on development and survival should be considered when employing Neurobasal culture medium.
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Affiliation(s)
- Joshua Hogins
- Departments of Psychiatry, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Devon C. Crawford
- Departments of Psychiatry, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Graduate Program in Neuroscience, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Charles F. Zorumski
- Departments of Psychiatry, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Anatomy & Neurobiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Steven Mennerick
- Departments of Psychiatry, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Anatomy & Neurobiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- * E-mail:
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Bohdan IM, Butsenko LM, Pasichnyk LA, Hvozdiak RI. [Absence of mutagenic effect of Pseudomonas syringae pv. atrofaciens 9400 and Pantoea agglomerans P324 culture liquids]. Mikrobiol Z 2010; 72:39-44. [PMID: 20812509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The mutagenic activity of the culture liquids of phytopathogenic strain Pseudomonas syringae pv. atrofaciens 9400 and epiphytic strain Pantoea agglomerans P324 was studied in the Ames test and Allium cepa-test. In pro- and eucariotic test-systems no effect of the culture liquids of these bacteria on spontaneous mutations of Salmonella typhimurium TA98 and TA100 or chromosome aberrations in the cells of Allium cepa root apical meristem was found.
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Hasegawa H, Gharaibeh DN, Lind EJ, Häse CC. Virulence of metalloproteases produced by Vibrio species on Pacific oyster Crassostrea gigas larvae. Dis Aquat Organ 2009; 85:123-131. [PMID: 19694172 DOI: 10.3354/dao02070] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Vibrio tubiashii, a pathogen of shellfish larvae and juveniles, produces several extracellular products. Here, we document that culture supernatants of several marine Vibrio species showed toxicity to oyster larvae. Treatment of these supernatants with EDTA not only severely diminished proteolytic activities, but also dramatically reduced toxicity to the larvae. Culture supernatants of metalloprotease-deficient mutants of V. tubiashii, V. cholerae, and V. splendidus were impaired in their ability to cause larval death compared to the wild type strains. Culture supernatants of Pseudomonas aeruginosa, known to contain several secreted proteases, showed virtually no toxicity to oyster larvae. Purified V. tubiashii protease A (VtpA), but not the prototype metalloprotease, thermolysin from Bacillus thermoproteolyticus, was highly toxic to the larvae. In addition, toxicity of purified VtpA was much greater for 6-d-old oyster larvae than for 16-d-old larvae. Together, these results indicated that culture supernatants of a variety of Vibrio species are highly toxic to oyster larvae and that the production of a metalloprotease is required for this effect. We propose that there are, as yet uncharacterized, specific substrates contained in larval tissue that are degraded by VtpA as well as certain homologous metalloproteases produced by other marine Vibrio species which, in turn, may contribute to vibriosis.
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Affiliation(s)
- Hiroaki Hasegawa
- Department of Biomedical Sciences, Oregon State University, Corvallis, Oregon 97331, USA
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Volpi Ghirardini A, Girardini M, Marchetto D, Pantani C. Microtox solid phase test: Effect of diluent used in toxicity test. Ecotoxicol Environ Saf 2009; 72:851-61. [PMID: 18471876 DOI: 10.1016/j.ecoenv.2008.01.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2007] [Revised: 01/09/2008] [Accepted: 01/13/2008] [Indexed: 05/23/2023]
Abstract
Microtox solid phase test is an acute toxicity test for solid matrices based on inhibition of natural bioluminescence of the marine bacterium Vibrio fischeri. Protocols developed to overcome the effects of confounding factors are proposed in the literature that differs by important practical and methodological issues. This work focused on diluents used for sediment resuspension and dilution. Two artificial seawaters, one natural seawater and two phosphate buffer solutions, were compared. The results showed that toxicity data obtained using different diluents were not comparable and that test sensitivity is highest using 0.1M phosphate buffer solution. The effects of medium on test organism were also investigated, in order to verify the capacity of media to maintain bioluminescence. The results underlined the importance of pH and Eh to explain the observed differences in toxicity.
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Affiliation(s)
- Annamaria Volpi Ghirardini
- Department of Environmental Sciences, University of Venice, Campo della Celestia 2737/b, I-30122 Venice, Italy
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16
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Li X, Huang Y, Wei ZC. [Degradation effect of two pure cultured ectomycorrhizal fungi on diesel]. Ying Yong Sheng Tai Xue Bao 2008; 19:1579-1584. [PMID: 18839922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The study on the growth characteristics of two ectomycorrhizal fungi Gomphidius viscidus and Laccaria bicolor under 10 g x L(-1) of diesel and their degradation effect on the diesel showed that both of the ectomycorrhizal fungi could utilize diesel as their only carbon source. After 14-day culture, the degradation effect was 39.90% for Laccaria bicolor and 31.32% for Gomphidius viscidus, and the degraded hydrocarbons were mainly 16C-22C alkenes. The capability of the ectomycorrhizal fungi to degrade diesel varied with the components of culture medium. When glucose was used as the second carbon source, the biodegradation capability of the fungi was inhibited, though the fungal biomass was 2-5 times as much as that without glucose addition. High concentration of inorganic nitrogen could promote the degradation effect to a certain extent, but not greatly.
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Affiliation(s)
- Xiao Li
- College of Environmental Science and Engineering, Peking University, Beijing 100871, China.
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17
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Harris JE, Friedland JS. l-Glutamate in Middlebrook 7H9 culture medium upregulates matrix metalloproteinase-2 secretion from human astrocytoma cells. J Neurosci Methods 2008; 173:291-4. [PMID: 18611410 DOI: 10.1016/j.jneumeth.2008.06.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2008] [Revised: 06/09/2008] [Accepted: 06/11/2008] [Indexed: 11/18/2022]
Abstract
Matrix metalloproteinases (MMPs) are implicated in the pathology of CNS tuberculosis. Whilst investigating the secretion of MMP-2 from human U373-MG astrocytoma cells, we observed elevated MMP-2 secretion in response to Middlebrook 7H9 media but not to Mycobacterium tuberculosis itself. Middlebrook 7H9 media did not stimulate MMP-1 or MMP-9 secretion from astrocytoma cells. The excitatory neurotransmitter l-glutamate, at concentrations found in Middlebrook 7H9 media, induced significant astrocytoma MMP-2 secretion (p<0.05). l-Glutamate-induced MMP-2 activity may contribute to neuropathology in various CNS diseases and may generate misleading data in pathogen studies where Middlebrook 7H9 is the culture medium.
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Affiliation(s)
- James E Harris
- Department of Infectious Diseases & Immunity, Imperial College London, Hammersmith Campus, Imperial College, Du Cane Road, London W12 0NN, UK
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18
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McClenahan DJ, Sotos JP, Czuprynski CJ. Cytokine response of bovine mammary gland epithelial cells to Escherichia coli, coliform culture filtrate, or lipopolysaccharide. Am J Vet Res 2006; 66:1590-7. [PMID: 16261834 DOI: 10.2460/ajvr.2005.66.1590] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To define the cytokine response of a cultured mammary gland epithelial cell line (ie, Mac-T) when incubated with Escherichia coli or its products. SAMPLE POPULATION Mac-T cells and E coli from cows with mastitis. PROCEDURE Mac-T cells were incubated with E coli or its products. The cytokine response of Mac-T cells to these treatments was quantified by measuring mRNA content of interleukin (IL)-1alpha, IL-1beta, IL-8, and tumor necrosis factor (TNF)-alpha by use of a quantitative reverse transcriptase-polymerase chain reaction assay. The amount of TNF-alpha secreted was also measured. RESULTS Treatment with E coli or its products resulted in significant increases in IL-1alpha, IL-8, and TNF-alpha mRNA content in Mac-T cells. This increase was reversible when culture filtrate was incubated with polymyxin B. The amount of IL-1beta mRNA in Mac-T cells increased only slightly over baseline after treatment with E coli or its products, but this increase was not diminished by incubation of E coli filtrate with polymyxin B. CONCLUSIONS AND CLINICAL RELEVANCE Incubation of Mac-T cells with E coli or its products resulted in increased amounts of IL1alpha, IL-8, and TNF-alpha mRNA. Inhibition of this response by incubation of culture filtrate with polymyxin B suggested that lipopolysaccharide was the main bacterial product that stimulated the cytokine response. The small increase in IL-1beta content in Mac-T cells incubated with E coli or its products suggested that this cytokine had a smaller role in the Mac-T cell response to E coli.
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Affiliation(s)
- David J McClenahan
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI 53706, USA
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19
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Mancini A, Borrelli A, Schiattarella A, Fasano S, Occhiello A, Pica A, Sehr P, Tommasino M, Nüesch JPF, Rommelaere J. Tumor suppressive activity of a variant isoform of manganese superoxide dismutase released by a human liposarcoma cell line. Int J Cancer 2006; 119:932-43. [PMID: 16550599 DOI: 10.1002/ijc.21904] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
A cell line derived from a pleiomorphic liposarcoma, named LSA, was previously reported to secrete (a) factor(s) exhibiting oncotoxic properties. The present article describes the isolation, purification and sequence analysis of a protein released by LSA cells into conditioned culture medium. This protein proved to be a variant isoform of manganese superoxide dismutase (MnSOD), hence its designation as LSA-type-MnSOD. This LSA-type-SOD differed from conventional SODs in its secretion by producer cells, contrasting with the normal localization of SODs in the mitochondrial matrix. Interestingly, during the protein purification process, LSA-type-SOD cosegregated with a cytotoxic activity directed against a number of tumor cell lines, as determined under in vitro conditions. This cytopathic effect was most likely due to LSA-type-SOD, since it could be fully reproduced using recombinant SOD that was expressed from cDNA clones isolated from LSA cells mRNA preparations and henceforth designated L-rSOD. In addition to its manifestation in cell lines kept in tissue culture, the oncotoxicity of LSA-type-SOD was further reflected in a remarkable capacity of this protein for suppression of mammary tumors in Balb-C-FR(III) mice. Animals subcutaneously injected with L-rSOD in the tumor area showed a complete disruption of established mammary carcinomas, as monitored by nuclear magnetic resonance (NMR) scanning. Moreover, metastatic spreading, which was readily detected in the control group, was suppressed in the treated animals. Altogether these data suggest that LSA-type-SOD interferes with survival and spreading of neoplastically transformed cells and deserves to be future validated as a therapeutic agent against cancer, either alone or in combination with conventional treatments.
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Affiliation(s)
- Aldo Mancini
- National Cancer Institute G. Pascale, Naples, Italy.
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20
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Deshmukh S, Asrani RK, Jindal N, Ledoux DR, Rottinghaus GE, Sharma M, Singh SP. Effects of Fusarium moniliforme culture material containing known levels of fumonisin B1 on progress of Salmonella Gallinarum infection in Japanese quail: clinical signs and hematologic studies. Avian Dis 2005; 49:274-80. [PMID: 16094834 DOI: 10.1637/7296-102804r] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
To study the individual and combined effects of fumonisin B1 (FB1) toxicity and Salmonella serotype Gallinarum infection, Japanese quail (Coturnix coturnix japonica) were fed Fusarium moniliforme culture material (2.5%), 150 mg FB1/kg ration, and were subsequently challenged orally with Salmonella Gallinarum organisms (2 x 10(4) colony-forming units) at 21 days of age. The chicks were fed culture material containing FB1 from day 5 till the end of the experiment. After being infected with Salmonella Gallinarum, observations were made 1, 2, 3, 5, 7, 10, 14, and 21 days postinfection. The clinical signs of diarrhea with bloody discharges were more pronounced in the Salmonella-infected birds on the FB1 diet. Mortality caused by Salmonella Gallinarum increased by 12% in the presence of FB1. Mean body weights in both the Salmonella-infected and FB1-fed groups were significantly lower than those of the controls at almost all intervals. Mean values of hemoglobin, packed cell volume, and total erythrocyte count were slightly higher in birds fed FB1 but were lower in the Salmonella Gallinarum groups fed FB1 and plain chick mash. Anemia was evident, between 5 and 10 days postinfection, in quail chicks infected with Salmonella Gallinarum alone. Total leukocyte counts were higher in Salmonella-infected and FB1-fed groups because of an increase in the number of heterophils and lymphocytes. However, the increase in lymphocyte response to infection was lower by 4.27%-30.09% between 3 and 21 days postinfection in the FB1-fed chicks compared with chicks infected with Salmonella Gallinarum. Alanine transaminase and total serum protein were slightly higher in both the infected and FB1-fed groups. This study revealed that the continuous presence of fumonisins in the diets of quail chicks might increase the susceptibility to or the severity of Salmonella Gallinarum infection.
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Affiliation(s)
- S Deshmukh
- Department of Veterinary Pathology, College of Veterinary and Animal Sciences, CSK Himachal Pradesh Agricultural University, Palampur-176 062, India
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21
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Tracqui P, Liu JW, Collin O, Clement-Lacroix J, Planus E. Global analysis of endothelial cell line proliferation patterns based on nutrient-depletion models: implications for a standardization of cell proliferation assays. Cell Prolif 2005; 38:119-35. [PMID: 15985057 PMCID: PMC6496877 DOI: 10.1111/j.1365-2184.2005.00337.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
It is known that cell populations growing in different environmental conditions may exhibit different proliferation patterns. However, it is not clear if, despite the diversity of the so-observed patterns, inherent cellular growth characteristics of the population can nevertheless be determined. This study quantifies the proliferative behaviour of the permanent endothelial human cell line, Eahy926, and establishes to which extent the estimation of the cell proliferation rate depends on variations of the experimental protocols. Cell proliferation curves were obtained for cells cultured over 16 days and the influences of cell seeding densities, foetal bovine serum content and frequency of culture medium changes were investigated. Quantitative dynamic modelling was conducted to evaluate the kinetic characteristics of this cell population. We proposed successive models and retained a nutrient-depletion toxicity dependant model, which takes into account the progressive depletion of nutrients, as well as the increase of toxicity in the cell culture medium. This model is shown to provide a very good and robust prediction of the experimental proliferation curves, whatever are the considered frequency of culture medium changes and serum concentrations. Thus, the model enables an intrinsic quantification of the parameters driving in vitro EAhy926 proliferation, including proliferation, nutrient consumption and toxicity increase rates, rather independently of the experiments design. We therefore propose that such models could provide a basis for a standardized quantification of intrinsic cell proliferation kinetics.
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Affiliation(s)
- P Tracqui
- CNRS, Laboratoire TIMC, Equipe Dynacell, Institut de l'Ingénierie et de l'Information de Santé (InS), Faculté de Médecine, 38706 La Tronche Cedex, France.
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22
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Signorini-Allibe N, Gonthier B, Lamarche F, Eysseric H, Barret L. CHRONIC CONSUMPTION OF ETHANOL LEADS TO SUBSTANTIAL CELL DAMAGE IN CULTURED RAT ASTROCYTES IN CONDITIONS PROMOTING ACETALDEHYDE ACCUMULATION. Alcohol Alcohol 2005; 40:163-71. [PMID: 15767272 DOI: 10.1093/alcalc/agh097] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIMS This study aimed at comparing the cerebral cytotoxicity of ethanol and its main metabolite acetaldehyde after acute or chronic exposures of rat astrocytes in primary culture. METHODS Cytotoxicity was evaluated on the cell reduction of viability (MTT reduction test) and on the characterization of DNA damage by single cell gel electrophoresis (or comet assay). RESULTS Changes in astrocyte survival and in DNA integrity only occurred when the astrocytes were chronically exposed to ethanol (20 mM; 3, 6 or 9 days). On the other hand, viability and DNA integrity were deeply affected by acute exposure to acetaldehyde. Both effects were dependent on the concentration of acetaldehyde. The cytotoxic effect of acetaldehyde was also indirectly evaluated after modifications of the normal ethanol metabolism by the use of different inducers or inhibitors. In presence of ethanol, the concomitant induction of catalase (i.e. by glucose oxidase) and inhibition of aldehyde dehydrogenase (i.e. by methylene blue) led to acetaldehyde accumulation within cells. It was followed by both a reduction in viability and a substantial increase in DNA strand breaks. CONCLUSIONS These data were thus consistent with a possible predominant role of acetaldehyde during brain ethanol metabolism. On the other hand, the effects observed after AMT could also suggest a possible direct ethanol effect and a role for free radical attacks. These data were thus consistent with a possible predominant role of acetaldehyde during brain ethanol metabolism. On the other hand, the effects observed after AMT could also suggest a possible direct ethanol effect and a role for free radical attacks.
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Affiliation(s)
- N Signorini-Allibe
- Laboratoire ORSOX (Oligoélements et Résistance au Stress Oxydant induit par les Xénobiotiques) UMR UJF/CEA-LCR CEA 8M, Université Joseph Fourier, La Tronche Cedex, France
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23
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van Minnen B, Stegenga B, van Leeuwen MBM, van Kooten TG, Bos RRM. A long-termin vitro biocompatibility study of a biodegradable polyurethane and its degradation products. J Biomed Mater Res A 2005; 76:377-85. [PMID: 16270347 DOI: 10.1002/jbm.a.30531] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The biological safety of degradation products from degradable biomaterials is very important. In this study a new method is proposed to test the cytotoxicity of these degradation products with the aim to save time, laboratory animals, and research funds. A biodegradable polyurethane (PU) foam was subjected to this test method. The PU had soft segments of DL-lactide/epsilon-caprolactone and hard segments synthesized from butanediol and 1,4-butanediiosocyanate. Copolymer foams without urethane segments, consisting of DL-lactide/epsilon-caprolactone, were tested as well. Accumulated degradation products were collected by degrading the foams in distilled water at 60 degrees C up to 52 weeks. Cell-culture medium was prepared from powder medium with this water. In different tests the cytotoxicity of this medium was established. The first signs of cytotoxicity were observed after 3-5 weeks of degradation. This accounts for both materials and reestablishes the good short-term biocompatibility of these materials. The PU showed more toxicity toward the end stages of degradation in comparison with the copolymer. This is probably related to the accumulation of degradation products of the urethane segments. In the in vivo situation the degradation of the PU and the metabolism and excretion of degradation products may differ. Therefore, long-term in vivo studies will have to establish whether these in vitro results are representative for the in vivo behavior of the degrading PU.
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Affiliation(s)
- B van Minnen
- Department of Oral and Maxillofacial Surgery, University Medical Center Groningen, University of Groningen, P.O. Box 30.001, 9700 RB Groningen, The Netherlands.
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Goodman AL, Kulasekara B, Rietsch A, Boyd D, Smith RS, Lory S. A Signaling Network Reciprocally Regulates Genes Associated with Acute Infection and Chronic Persistence in Pseudomonas aeruginosa. Dev Cell 2004; 7:745-54. [PMID: 15525535 DOI: 10.1016/j.devcel.2004.08.020] [Citation(s) in RCA: 440] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2004] [Revised: 08/27/2004] [Accepted: 08/30/2004] [Indexed: 10/26/2022]
Abstract
The opportunistic pathogen Pseudomonas aeruginosa causes a variety of acute and chronic infections. We identified a gene whose inactivation results in attenuation of virulence due to premature activation of genes involved in biofilm formation and coordinate repression of genes required for initial colonization. This gene, retS, encodes a hybrid sensor kinase/response regulator with an unconventional arrangement of functional domains. Genome-wide transcriptional profiling indicates that the retS gene is required for expression of the Type III secretion system and other virulence factors and for repression of genes responsible for exopolysaccharide components of the P. aeruginosa biofilm matrix. These disparate phenotypes are suppressed by transposon insertions in genes encoding the GacS/GacA/rsmZ signal transduction pathway, a highly conserved system involved in the control of diverse adaptive functions. This study defines RetS as a pleiotropic regulator of multiple virulence phenotypes that orchestrates genes required for acute infection and genes associated with chronic persistence.
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Affiliation(s)
- Andrew L Goodman
- Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115, USA
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25
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Lonergan P, Pedersen HG, Rizos D, Greve T, Thomsen PD, Fair T, Evans A, Boland MP. Effect of the Post-Fertilization Culture Environment on the Incidence of Chromosome Aberrations in Bovine Blastocysts1. Biol Reprod 2004; 71:1096-100. [PMID: 15189826 DOI: 10.1095/biolreprod.104.030635] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
We have previously shown that the postfertilization embryo culture environment has a significant influence on the quality of the resulting bovine blastocyst measured in terms of its cryotolerance and relative abundance for several developmentally important gene transcripts. Using three different culture conditions known to produce blastocysts of differing quality, the objective of this study was to examine whether the postfertilization culture environment had an effect on the incidence of mixoploidy in bovine blastocysts. Presumptive zygotes, produced by in vitro maturation and fertilization, were cultured in vitro in synthetic oviduct fluid (SOF) medium in the absence or presence of fetal calf serum (FCS), or in vivo in the ewe oviduct. Blastocysts were recovered from the three systems at Day 7 and the incidence of mixoploidy was assessed using fluorescence in situ hybridization with chromosome 6- and chromosome 7-specific probes. A total of 10 025 nuclei were scored in 122 blastocysts. The frequency of normal, diploid, blastocysts was 8.8%, 21.4%, and 34.8% in embryos derived from culture in SOF+FCS, SOF, and the ewe oviduct, respectively, the remainder showing some degree of mixoploidy. The incidence of mixoploidy was apparently not related to the presence of serum; omission of serum from SOF resulted in a reduction in the incidence of mixoploidy (91.2% vs. 78.6%), although this difference was not significant. Culture in vivo, however, resulted in a significant (P < 0.01) reduction in the incidence of mixoploidy compared with culture in vitro in the presence of serum (65.2% vs. 91.2%, respectively). Among the mixoploid blastocysts, the majority contained less than 10% polyploid cells, irrespective of culture group (SOF, 69.7%; SOF+FCS, 64.5%; ewe oviduct, 60.0%). More than one type of polyploidy was frequently observed in mixoploid blastocysts. Overall, diploidy-triploidy was the most frequent abnormality, but diploid-tetraploid and diploid-triploid-tetraploid mosaics were also observed. A significantly higher proportion (P < 0.05) of blastocysts derived from SOF+FCS had more than one type of abnormality (80.6%, 25/ 31) compared with those derived from SOF (45.4%, 15/33) or in vivo culture (53.3%, 16/30). In conclusion, the postfertilization culture environment of the developing embryo can affect the incidence and severity of mixoploidy in the resulting blastocyst.
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Affiliation(s)
- Patrick Lonergan
- Department of Animal Science and Production, University College Dublin, Lyons Research Farm, Newcastle, County Dublin, Ireland.
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26
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Shin M, Nguyen T, Ramsay J. Evaluation of support materials for the surface immobilization and decoloration of amaranth by Trametes versicolor. Appl Microbiol Biotechnol 2002; 60:218-23. [PMID: 12382067 DOI: 10.1007/s00253-002-1088-3] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2002] [Revised: 06/24/2002] [Accepted: 07/07/2002] [Indexed: 10/27/2022]
Abstract
The ability of Trametes versicolor ATCC 20869 to colonize several natural and synthetic materials (wheat straw, jute, hemp, maple woodchips, and nylon and polyethylene teraphthalate fibers) and to subsequently decolorize amaranth was evaluated. Jute was found to be the best support material as T. versicolor grew well on it without color leaching from the support and without loss of the jute's integrity over a 4 week period. The fungus immobilized on jute, straw and hemp decolorized amaranth (50 mg l(-1)) at a rate of about 5 mg l(-1) h(-1) without glucose being added. When 1 g l(-1) glucose was added, the dye was degraded more quickly (about 8 mg l(-1) h(-1)). Decoloration did not occur in a suspension culture without glucose. As the number of decoloration cycles increased, the rate of decoloration decreased. This rate was restored to its original level after the biomass was incubated in fresh growth medium for 5 days. With all immobilization supports, the toxicity of the medium before and after decoloration was the same or lower.
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Affiliation(s)
- M Shin
- Department of Chemical Engineering, Queen's University, Kingston, Ontario, K7L 3N6, Canada
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27
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Ginsburg I, Sadovnic M, Yedgar S, Kohen R, Hrbac J. Hemolysis of human erythrocytes by hypochlorous acid is modulated by amino acids, antioxidants, oxidants, membrane-perforating agents and by divalent metals. Free Radic Res 2002; 36:607-19. [PMID: 12180186 DOI: 10.1080/10715760290029092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The optimal conditions under which hypochlorous acid (NaOCl) either hemolyzes human RBC or kills monkey kidney epithelial cells (BGM) in culture had been investigated. While in Hank's balanced salt solution (HBSS), micromolar amounts of NaOCl caused full hemolysis and also killed BGM cells, in D-MEM or RPMI media rich in amino acids, 25-40 mM of hypochlorite were needed to induce cell injury. Cells exposed to high amounts of NaOCl became highly refractory to strong detergents. Hemolysis by NaOCl was strongly inhibited by a large variety of antioxidants. RBC treated by subtoxic concentrations either of peroxide, peroxyl radical, NO, cholesterol, PLA2, PLC as well as by N2, argon or by mixture of CO2 (10%) and O2 (90%) became much more susceptible to lysis by NaOCl. On the other hand, while RBC treated by Fe2+, Co2+, and V2+ and to a lesser extent with Cu2+ became highly resistant to NaOCl hemolysis presumably due to NaOCl decomposition, no such effect was found either with Co2+ or by Mn2+. RBC treated by azide to destroy catalase and then incubated with peroxide and with NaOCl failed to undergo hemolysis due to the ability of peroxide to decompose NaOCl. The inhibitory effects of the divalent metals on NaOCl-induced hemolysis were also substantiated by measuring the decrease in pH and by cyclic voltammetry. The findings that like peroxide, NaOCl also synergizes with membrane-perforating agents and with a protease to kill epithelial cells further implicate such "cocktails" in cell injury in inflammatory conditions. Taken together, because of the capacity of many agents to scavenge NaOCl, tissue damage by NaOCl-generated neutrophils can take place primarily if activated neutrophils closely adhere to target cells to avoid the scavenging effects of amino acids and of antioxidants. Therefore, the significance of the data which had tested the cytotoxic effects of NaOCl using cells suspended only in salt solutions, should be reconsidered.
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Affiliation(s)
- Isaac Ginsburg
- Department of Oral Biology, Hadassha Faculty of Dental Medicine, Hebrew University, Jerusalem, Israel.
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Abstract
The aim of this study was to select a cryoprotectant for use in attempts to preserve tissues and organs by vitrification. The first step was to select a cell line with which to compare the toxicity of a range of commonly used cryoprotectants. An immortal vascular endothelial cell (ECV304) was exposed to vitrifying concentrations of four cryoprotectants: dimethyl sulfoxide (Me(2)SO; 45% w/w); 2,3 butanediol (BD; 32%); 1,2-propanediol (PD; 45%); and ethanediol (ED; 45%). Three times of exposure (1, 3, and 9 min) and two temperatures (22 and 2-4 degrees C) were studied. After removal of the cryoprotectant, the ability of the cells to adhere and divide in culture over a 2-day period was measured and expressed as a Cell Survival Index (CSI). There was no measurable loss of cells after exposure to the four cryoprotectants but 3-min exposure to BD, PD, or Me(2)SO at room temperature completely destroyed the ability of the cells to adhere and divide in culture. In contrast, exposure to all four cryoprotectants at 2-4 degrees C for up to 9 min permitted the retention of significant cell function, the CSIs, as a proportion of control, being 76.3+/-7.0% for BD, 63.6+/-7.1% for PD, 37.0+/-4.1 for Me(2)SO, and 33.2+/-3.0 for ED. The permeability properties of the cells for these four cryoprotectants was also measured at each temperature. Permeability to water was high, L(p) approximately equal 10(-7) cm/s/atm at 2-4 degrees C with all the cryoprotectants, but there were substantial differences in solute permeability: BD and PD were the most permeable at 2-4 degrees C (P(s)=4.1 and 3.0 x 10(-6) cm/s, respectively). Equilibration of intracellular cryoprotectant concentration was rapid, due in part to high water permeability; the cells were approximately 80% of their physiological volume after 10 min. Treatment at 2-4 degrees C with BD was the least damaging, but PD was not significantly worse. Exposure to vitrifying concentrations of ED and Me(2)SO, even at 2-4 degrees C, was severely damaging. Segments of rabbit carotid artery were treated with vitrifying concentrations of each of the two most favorable cryoprotectants, BD and PD, for 9 min. It was shown that each cryoprotectant reduced smooth muscle maximum contractility to a similar extent and abolished the acetylcholine response. However, vital staining revealed that exposure to BD also caused substantial damage to the endothelial lining, whereas the endothelium was completely intact after PD exposure, raising the possibility that the effect of PD on NO release may be reversible. In later stages of this project it is planned to use dielectric heating to rewarm the tissues and thereby avoid devitrification. The effects of each cryoprotectant on this mode of heating was therefore studied. Gelatin spheres containing vitrifiable concentrations of each cryoprotectant were rewarmed from -60 degrees C in a radiofrequency applicator. Because the uniformity of heating is related to the dielectric properties of the material, these properties were also measured. PD was the most suitable. These physical measurements, combined with the measurements of toxicity and permeability, indicate that PD is the most favorable cryoprotectant of those tested for use in subsequent stages of this study.
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Affiliation(s)
- Monica C Wusteman
- Medical Cryobiology Unit, Department of Biology, University of York, York YO10 5YW, UK.
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29
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Abstract
We have developed a new method for culturing cells that maintains their health and sterility for many months. Using conventional techniques, primary neuron cultures seldom survive more than 2 months. Increases in the osmotic strength of media due to evaporation are a large and underappreciated contributor to the gradual decline in the health of these cultures. Because of this and the ever-present likelihood of contamination by airborne pathogens, repeated or extended experiments on any given culture have until now been difficult, if not impossible. We surmounted survival problems by using culture dish lids that form a gas-tight seal, and incorporate a transparent hydrophobic membrane (fluorinated ethylene-propylene) that is selectively permeable to oxygen (O(2)) and carbon dioxide (CO(2)), and relatively impermeable to water vapor. This prevents contamination and greatly reduces evaporation, allowing the use of a non-humidified incubator. We have employed this technique to grow dissociated cortical cultures from rat embryos on multi-electrode arrays. After more than a year in culture, the neurons still exhibit robust spontaneous electrical activity. The combination of sealed culture dishes with extracellular multi-electrode recording and stimulation enables study of development, adaptation, and very long-term plasticity, across months, in cultured neuronal networks. Membrane-sealed dishes will also be useful for the culture of many other cell types susceptible to evaporation and contamination.
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Affiliation(s)
- S M Potter
- 156-29 Division of Biology, California Institute of Technology, Pasadena, CA 91125, USA.
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30
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Abstract
Certain yeast strains secrete a protein toxin, which inhibits the growth of sensitive pathogens and yeasts. Studies have shown that production of the toxin is dependent on presence of linear, double-stranded DNA plasmids in the killer yeasts. In the yeast Pichia pastoris, two linear double-stranded DNA plasmids have been identified. In the present study, the search for toxin-producing capability in P. pastoris has been conducted. No killer activity could be detected when 14 different indicator strains were tested.
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Affiliation(s)
- H Banerjee
- Department of Biology, Long Island University, Brooklyn Campus, New York, 11201-8423, USA
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Balebona MC, Krovacek K, Moriñigo MA, Mansson I, Faris A, Borrego JJ. Neurotoxic effect on two fish species and a PC12 cell line of the supernate of Vibrio alginolyticus and Vibrio anguillarum. Vet Microbiol 1998; 63:61-9. [PMID: 9810622 DOI: 10.1016/s0378-1135(98)00227-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The biological effects of supernates obtained from different strains of Vibrio alginolyticus and Vibrio anguillarum isolated from diseased fish have been studied by inoculation on two fish species, eel and rainbow trout, and two fish cell lines. These supernates possess neuroexcitatory properties, and so, when they are injected into both fish species, they trigger convulsions, wriggling, contortive swimming and respiratory arrest coupled with increased respiratory reflex. Furthermore, after the application of the supernates on cultures of noradrenergic pheochromocytoma PC12 cells, an increase of acetylcholine, released from the cells was obtained. The amount of released acetylcholine depends on the source of assayed supernates and on the dose applied to the cells. On the basis of the results obtained with PC12 cells, we suggest that the supernates from pathogenic Vibrio strains injected into fish may elicit an increased release of acetylcholine in the motor endplate of some muscles related to locomotion and ventilation of the inoculated fish.
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Affiliation(s)
- M C Balebona
- Department of Microbiology, Faculty of Sciences, University of Malaga, Spain
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32
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Abstract
We assayed the tolerance to solvents of three toluene-degrading Pseudomonas putida strains and Pseudomonas mendocina KR1 in liquid and soil systems. P. putida DOT-T1 tolerated concentrations of heptane, propylbenzene, octanol, and toluene of at least 10% (vol/vol), while P. putida F1 and EEZ15 grew well in the presence of 1% (vol/vol) propylbenzene or 10% (vol/vol) heptane, but not in the presence of similar concentrations of octanol or toluene. P. mendocina KR1 grew only in the presence of heptane. All three P. putida strains were able to become established in a fluvisol soil from the Granada, Spain, area, whereas P. mendocina KR1 did not survive in this soil. The tolerance to organic solvents of all three P. putida strains was therefore assayed in soil. The addition to soil of 10% (vol/wt) heptane or 10% (vol/wt) propylbenzene did not affect the survival of the three P. putida strains. However, the addition of 10% (vol/wt) toluene led to an immediate decrease of several log units in the number of CFU per gram of soil for all of the strains, although P. putida F1 and DOT-T1 subsequently recovered. This recovery was influenced by the humidity of the soil and the incubation temperature. P. putida DOT-T1 recovered from the shock faster than P. putida F1; this allowed the former strain to become established at higher densities in polluted sites into which both strains had been introduced.
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Affiliation(s)
- M J Huertas
- Department of Plant Biochemistry, Consejo Superior de Investigaciones Científicas, Estación Experimental del Zaidín, Granada, Spain
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Trotman AA, David PP, Bonsi CK, Hill WA, Mortley DG, Loretan PA. Integrating biological treatment of crop residue into a hydroponic sweetpotato culture. Adv Space Res 1997; 20:1805-13. [PMID: 11542554 DOI: 10.1016/s0273-1177(97)00845-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Residual biomass from hydroponic culture of sweetpotato [Ipomoea batatas (L.) Lam.] was degraded using natural bacterial soil isolates. Sweetpotato was grown for 120 days in hydroponic culture with a nutrient solution comprised of a ratio of 80% modified half Hoagland solution to 20% filtered effluent from an aerobic starch hydrolysis bioreactor. The phytotoxicity of the effluent was assayed with Waldmann's Green' lettuce (Lactuca sativa L.) and the ratio selected after a 60-day bioassay using sweetpotato plants propagated vegetatively from cuttings. Controlled environment chamber experiments were conducted to investigate the impact of filtrate from biological treatment of crop residue on growth and storage root production with plants grown in a modified half Hoagland solution. Incorporation of bioreactor effluent, reduced storage root yield of 'Georgia Jet' sweetpotato but the decrease was not statistically significant when compared with yield for plants cultured in a modified half Hoagland solution without filtrate. However, yield of 'TU-82-155' sweetpotato was significantly reduced when grown in a modified half Hoagland solution into which filtered effluent had been incorporated. Total biomass was significantly reduced for both sweetpotato cultivars when grown in bioreactor effluent. The leaf area and dry matter accumulation were significantly (P < 0.05) reduced for both cultivars when grown in solution culture containing 20% filtered effluent.
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Affiliation(s)
- A A Trotman
- Tuskegee University NASA Center for CELSS, AL, 36088, USA
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Shchetynina VM, Shynkarenko AO, Moskalenko VM, Verezub LH, Manina ZM, Myronenko LH, Zhdamarova LA. [The toxin-containing filtrates from the culture broths of clinical strains of Corynebacterium diphtheriae]. Mikrobiol Z 1997; 59:65-70. [PMID: 9172866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Composition as well as toxicity and antigenicity of toxin-including filtrates of 6 circulating strains of Corynebacterium diphtheriae, isolated in 1992-1994 in the city of Kharkiv have been studied as compared with production strain PW-8. It is shown that toxicity of filtrates of circulating strains was analogous of toxicity of the strain PW-8 (100 dlm) or lower (45 dlm). Antigenicity of four strains which was expressed in if units proved to be higher than that of the production strains and it was considerably higher in two strains isolated from adults who died from diphtheria. The methods of gel-filtration and immunoprecipitation were used to establish differences between strains in their capacity to preferential accumulation of different molecular forms of toxin under stationary cultivation.
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Abstract
Lettuce plants were grown utilizing water, inorganic elements, and CO2 inputs recovered from waste streams. The impact of these waste-derived inputs on the growth of lettuce was quantified and compared with results obtained when reagent grade inputs were used. Phytotoxicity was evident in both the untreated wastewater stream and the recovered CO2 stream. The toxicity of surfactants in wastewater was removed using several treatment systems. Harmful effects of gaseous products resulting from incineration of inedible biomass on crop growth were observed. No phytotoxicity was observed when inorganic elements recovered from incinerated biomass ash were used to prepare the hydroponic solution, but the balance of nutrients had to be modified to achieve near optimal growth. The results were used to evaluate closure potential of water and inorganic elemental loops for integrated plant growth and human requirements.
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Affiliation(s)
- K Wignarajah
- Lockheed Martin Engineering and Science Corporation, NASA Ames Research Center, Moffett Field, CA 94035, USA
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36
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Abstract
OBJECTIVE To compare different culture media for their effects on sperm motility and lipid peroxidation. DESIGN The ability of four different culture media to sustain the motility of human spermatozoa during an overnight incubation was examined in relation to the induction of lipid peroxidation. The role of transition metals in the genesis of peroxidative damage was investigated in experiments involving the addition of iron or the chelating reagent ethylenediamine tetra acetic acid (EDTA). SETTING Academic research institute. MAIN OUTCOME MEASURES The generation of malondialdehyde and 4-hydroxyalkenals after the addition of a ferrous ion promoter and the measurement of sperm motility. RESULTS Spermatozoa incubated in Ham's F-10 medium (GIBCO, Paisley, Scotland) exhibited a marked loss of motility in association with a significant increase in peroxidative damage. Addition of EDTA to Ham's F-10 medium significantly reduced the degree of lipid peroxidation and induced a simultaneous increase in sperm motility. CONCLUSIONS Ham's F-10 medium is a suboptimal medium for the long-term culture of human spermatozoa because it induces peroxidative damage and a concomitant decline of sperm motility.
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Affiliation(s)
- E Gomez
- Medical Research Council Reproductive Biology Unit, Centre for Reproductive Biology, Edinburgh, Scotland
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Abstract
A batch of silicone oil (dimethylpolysiloxane) is described which had differential effects on the development of 1- and 2-cell preimplantation mouse embryos in vitro when used as a microdrop overlay over two culture media: CZB and KSOM. A high rate of development into blastocysts was observed when using CZB medium; in contrast, development was strongly inhibited when KSOM was used. Other batches of silicone oil or paraffin oil permitted development from the zygote to the blastocyst of an outbred strain of mouse without arrest at the 2-cell stage. Our results show that the higher concentrations of ethylenediaminetetraacetic acid (EDTA) and bovine serum albumin (BSA) in CZB medium, in comparison with KSOM, protect against the toxic component in the oil. Observations also gave circumstantial evidence that the toxic component in the oil is zinc. The beneficial effect of including EDTA in a medium is usually attributed to its chelating toxic metals introduced as impurities in other components of the medium. Our results now show that EDTA also protects against impurities in the oil overlay.
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Affiliation(s)
- G T Erbach
- Laboratory of Human Reproduction and Reproductive Biology, Harvard Medical School, USA
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Abstract
The factors which limit the proliferation of eukaryotic cells in vitro are still not well known. Ammonia is believed to be toxic for mammalian cell proliferation and secretion. We have tried two approaches to reducing the ammonia in the medium. We first limited the ammonia produced by the cells by replacing glutamine by glutamate. Then, we used two chemical engineering methods to eliminate accumulated ammonia. In one the used medium was passed through a natural cation exchanger: the clinoptilolite. In the other, the culture medium was passed through a hydrophobic microporous hollow fiber module. Replacing the glutamine by glutamate reduced the medium ammonia concentration. The physicochemical removal of ammonia induced a better cell growth, but not a better specific antibody secretion.
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Affiliation(s)
- J Capiaumont
- Laboratoire de Biochimie Médicale, Pr Nabet, Faculté de Medecine, Nancy, France
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Abstract
The amino acid glutamine is an essential nutrient for cells in culture. In aqueous solutions such as liquid culture media, glutamine spontaneously decomposes into ammonia. In this study, we examined the toxicity of ammonia for two different cell lines. In mouse hybridoma cell cultures, viable cell counts were reduced at exogenous ammonia concentrations of 1000 microM. In the human promyelocytic cell line however, viable cell counts were shown to be reduced at exogenous ammonia concentrations of 300 microM. Next, we determined ammonia and glutamine levels in 11 commercially available media on the day of delivery. It was found that all media contained significantly less glutamine than prescribed. Ammonia was found in all media with concentrations ranging up to 1000 microM. Storage at both 4 degrees C and 20 degrees C caused a further degradation of glutamine and significant accumulation of ammonia in all media. The degradation curves of the various media were used to calculate the first order degradation constant k, which can be used to determine the kinetics of the spontaneous decomposition in culture media. These results suggest that precautions must be taken to avoid the deterioration of commercially available culture media, because of the decay of glutamine. Long storage times lead to a rapid decay of glutamine and an accumulation of the toxic degradation product ammonia.
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Affiliation(s)
- S Heeneman
- Department of Surgery, University of Limburg, Maastricht, Netherlands
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Abstract
It has been known for several decades that cultured murine cells undergo a defined series of changes, i.e., an in vitro evolution, which includes crisis, spontaneous transformation ('immortalization'), aneuploidy, and spontaneous neoplastic transformation. These changes have been shown to be caused by the in vitro environment rather than an inherent instability of the murine phenotype or genotype. Serum amine oxidases were recently identified as a predominant cause of crisis. These enzymes generate hydrogen peroxide from polyamine substrates that enter the extracellular milieu. This finding implicates free-radical toxicity as the underlying cause of in vitro evolution. We propose an oxyradical hypothesis to explain each of the stages of in vitro evolution and discuss its significance for cytotechnology and long-term cultivation of mammalian cell types.
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Affiliation(s)
- R E Parchment
- Division of Pharmacology & Toxicology, Hipple Cancer Research Center, Dayton, Ohio 45439-2092
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41
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Abstract
Results of the Viking mission seem to indicate that there is a ubiquitous layer of highly oxidizing aeolian material covering the Martian surface. This layer is thought to oxidize organic material that may settle on it, and is therefore responsible for the lack of detection of organic matter on the planet's surface by Viking. The mechanism that creates the oxidizing condition is not well understood, nor is the extent of the oxidation potential of this material. It has been suggested that the oxidizing nature of the soil is due to photochemical reactions which create hydrogen peroxide and superoxides in the surface soil. One question of importance to planetary protection regarding this material is, what is its potential for destroying terrestrial microorganisms, thus making the surface of Mars "self-sterilizing"? Using data obtained by the gas exchange experiment on Viking, and for simplicity assuming that all of the O2 released came from H2O2, the concentration range for H2O2 on the surface of Mars can be calculated to be 25-250 ppm. The microbial disinfection rate by H2O2 is concentration dependent, and is highly variable within the microbial community. Data from our laboratory indicate that certain soil bacteria survive and grow to stationary phase in 30,000 ppm H2O2. However, the total number of organisms decreases in the presence of H2O2. These results indicate that it is doubtful that the presence of H2O2 alone on Mars would make the surface "self-sterilizing".
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Affiliation(s)
- R L Mancinelli
- Solar System Exploration Branch, NASA/Ames Research Center, Moffett Field, CA 94035
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Abstract
Previously we observed that Staphylococcus aureus phagocytized by cultured bovine endothelial cells do not proliferate intracellularly, but are cytotoxic to bovine endothelial cells. To investigate S. aureus virulence factors which may be produced intracellularly and cause lysis of endothelial cells, we tested S. aureus mutants defective in production of one or more potential virulence factors and corresponding parent strains for cytotoxicity to endothelial cell monolayers subsequent to being ingested. Following incubation of endothelial cell monolayers with S. aureus for 3.5 h, cultures were supplemented with lysostaphin to destroy extracellular but not intracellular S. aureus. At subsequent times, viability of endothelial cells was assayed by retention of 3H-adenine and the number of intracellular S. aureus was measured. The cytotoxic activity of S. aureus culture supernatants was also characterized. The results indicate that S. aureus alpha-hemolysin is cytotoxic to bovine endothelial cells and plays an important role in the damage suffered by bovine endothelial cell monolayers following ingestion of S. aureus. Ingestion of alpha-hemolysin-producing S. aureus by endothelial cells in vivo might be expected to result in destruction of endothelium followed by development of platelet-fibrin vegetations. This possible sequence of events is compatible with the frequently fulminant course of S. aureus endocarditis.
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Affiliation(s)
- J M Vann
- Department of Medical Microbiology, University of Wisconsin Medical School, Madison 53706
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Handler ES, Mordes JP, Seals J, Koevary S, Like AA, Nakano K, Rossini AA. Diabetes in the Bio-Breeding/Worcester rat. Induction and acceleration by spleen cell-conditioned media. J Clin Invest 1985; 76:1692-4. [PMID: 4056046 PMCID: PMC424167 DOI: 10.1172/jci112156] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Injections of media conditioned by concanavalin A-activated spleen cells from acutely diabetic rats accelerated the appearance of diabetes in young Bio-Breeding/Worcester (BB/W) rats. Activity was also found in media conditioned by spleen cells from nondiabetic, W-line Wistar Furth and Buffalo rats. Unconditioned media containing mitogen had no activity. Conditioned media also induced diabetes in resistant W-line BB/W rats but not in Wistar Furth rats. A soluble factor may activate a BB lymphocyte population that promotes diabetes.
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Abstract
Hamster 2-cell embryos were transferred to recipients to provide information on the block to development in vitro. Previous attempts to elucidate this block have focused on possible deficiencies in the culture medium. In this study the possibility was examined that the media used for embryo collection are actually embryotoxic. Two-cell embryos obtained from superovulated mated hamsters were exposed to collection media [either a Hepes-buffered modified Tyrode's solution (TALP-Hepes) or PB1] during either a "fast transfer" procedure (time elapsed from collection to transfer 3.9 +/- 0.7 min or 3.7 +/- 0.9 min, respectively) or a "slow transfer" procedure (time elapsed 19.1 +/- 4.4 min or 20.8 +/- 5.7 min, respectively). In each transfer experiment, equal numbers of embryos from the same donor pool were transferred to one oviduct (fast transfer) and to the contralateral oviduct (slow transfer) of the same recipient. Embryos were recovered 33-36 h after transfer; embryos developing at least to the 8-cell stage were considered viable. Significant differences were found (P less than 0.005) between the viability of embryos subjected to fast and slow transfer procedures using either TALP-Hepes (embryo survival 60.8% vs. 22.2%, respectively, difference 38.6%) or PB1 (survival 50.6% vs. 10.5%, respectively, difference 40.1%). These data show that length of exposure to collection media is an important variable in determining subsequent developmental ability of 2-cell hamster embryos.(ABSTRACT TRUNCATED AT 250 WORDS)
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Glinos AD, Bardi GN, Dermitzaki KC, Perez SA, Talieri MJ. Cytokinetic and cytotoxic effects of urea on HeLa cells in suspension cultures. J Natl Cancer Inst 1983; 71:1211-9. [PMID: 6581359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Total and viable cell counts, differential mitotic cell counts, and incorporation of tritiated thymidine were used to study the kinetics of suspension cultures of HeLa cells exposed to urea concentrations of 0.5-1.5%. Aside from any nonspecific osmotic effects, urea concentrations of 1.0-1.4% exhibited significant cytokinetic and cytotoxic effects. Most characteristically, mitotic cells arrested in metaphase began to accumulate 4-6 hours after addition of urea and reached a peak at 15-18 hours. Thus when the cells were in the S-phase or at the S/G2 boundary at the time of addition of urea, they exhibited metaphase arrest. Subsequently, cultures continuously exposed to urea showed a decline in the mitotic index, indicating that the entry rate of cells into mitosis is lower than the rate at which cells escape from the mitotic block. Such cultures exhibited numerous abnormal and abortive mitoses and a decrease in growth and viability of the cell populations. In contrast to the initial single wave of arrested mitosis seen with continuous exposure to urea, intermittent exposure on alternate days resulted in successive waves of arrested metaphases and had considerably more pronounced effects on the growth and viability of the cultures.
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Wakeland JR, Crie JS, Wildenthal K. Toxicity to organ cultured hearts of media prepared with disposable filter units. In Vitro 1982; 18:715-718. [PMID: 7129486 DOI: 10.1007/bf02796427] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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Abstract
The recovery of several strains of Salmonella typhimurium LT-2 which had first been grown in minimal medium varies when the organisms are grown on minimal medium agar and complex medium agar. The strains tested included mutants with deficiencies in DNA-repair systems (uvrB-and rec-), a deep rough (rfa-) mutant, and a double mutant carrying both the uvrB- and the rfa-mutation. The uvrB- and rec-mutations imparted sensitivity to complex medium agar. The rfa-mutation suppressed the sensitivity of the uvrB-mutant to complex medium agar. Differences in colony-forming ability were not observed when the bacteria were first grown in the complex medium broth.
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