Cytotoxic Effects of Bulk-Fill Composites on L929 Fibroblast Cells / Efeitos citotóxicos dos compósitos bulk-fill em células de fibroblastos L929

Objective: Unlike traditional composite resins, bulk-fill composite resins could be polymerized as thicker layers. This study aims to contribute to the field by investigating the cytotoxic effects of various bulk-fill composite resins on L929 mouse fibroblast cells in vitro. Material and Methods: In our study, six bulk fill and one conventional composite resin were used. Composite resin samples (8×4 mm) were prepared in a sterile cabinet by using a glass mod and polymerizing with a led light device (DTE LUX E, Germany). Composite samples (n:3) of which surface area was calculated according to ISO 10993-12: 2012 standards (3 cm2/ml), were kept in media for 24 h and 72 h in 37 oC incubator, their extracts were filtered in 1:1 and 1:2 proportion and were added on L929 mouse fibroblast cells. Cell viability was examined by the MTT assay and cell death by the LDH test. Cell viability results were evaluated using one-way analysis of variance (ANOVA) test (p<0.05). Results: When the 1:1 extracts from 4 mm thick bulk-fill composite samples were applied on L929 mouse fibroblast cells, cell viability rates showed significant differences compared to the control group at the end of 24 h and 72 h (except for Estelite Bulk Fill Flow). Although the extracts of the tested composite samples at 1:1 and 1:2 ratio at the end of 72 hours caused a decrease in L929 mouse fibroblast cell viability, the cell viability rate of only PRG-containing bulk fill composite and conventional composite remained below the cell viability ratio (70%) specified in ISO standards. Bulk fill composites did not produce toxic effects (except Beautifil Bulk Restorative) according to the LDH test. Conclusions: Despite decreasing in general the cell viability, bulk-fill composite resins used in 4 mm thick layers provided cell viability rates over the acceptability level, except PRG-containing bulk fill composite (Beautifil Bulk Restorative), which was cytotoxic to L929 mouse fibroblasts. (AU)

Objetivo: Ao contrário das resinas compostas tradicionais, as resinas compostas bulk-fill podem ser polimerizadas como camadas mais espessas. Este estudo visa investigar in vitro os efeitos citotóxicos de várias resinas compostas bulk-fill em células de fibroblastos de camundongo L929.Material e Métodos: Em nosso estudo, seis resinas tipo bulk fill e uma resina composta convencional foram usadas. Amostras de resina composta (8 × 4 mm) foram preparadas em gabinete estéril usando um molde de vidro e polimerizado com um dispositivo de luz LED (DTE LUX E, Alemanha). Amostras compostas (n=3) cuja área de superfície foi calculada de acordo com os padrões ISO 10993-12:2012 (3cm2/ml), foram mantidas em meio e incubadas por 24 h e 72 h a 37 ºC, seus extratos foram filtrados na Proporção de 1:1 e 1:2 e foram acondicionados em cultura de células de fibroblastos de camundongo L929. A viabilidade celular foi examinada pelo ensaio MTT e a morte celular pelo teste LDH. Os resultados de viabilidade celular foram avaliados usando o teste de análise de variância (ANOVA) um fator (p <0,05). Resultados: Quando os extratos foram plaqueados na proporção 1:1 de amostras de compósito bulk-fill de 4 mm de espessura com as células de fibroblastos de camundongo L929, as taxas de viabilidade celular mostraram diferenças significativas em comparação com o grupo controle no final de 24 h e 72 h (exceto para Estelite Bulk Fluxo de enchimento). Embora os extratos das amostras compostas testadas na proporção de 1:1 e 1:2 ao final de 72 horas tenham causado uma diminuição na viabilidade das células de fibroblastos de camundongo L929, a taxa de viabilidade celular apenas do compósito de preenchimento total contendo PRG e o compósito convencional permaneceram abaixo a taxa de viabilidade celular (70%) especificada nas normas ISO. Os compósitos de preenchimento a granel não produziram efeitos tóxicos (exceto Beautifil Bulk Restorative) de acordo com o teste de LDH. Conclusão: Apesar de diminuir em geral a viabilidade celular, as resinas compostas bulk-fill usadas em camadas de 4 mm de espessura forneceram taxas de viabilidade celular acima do nível aceitável, exceto o compósito bulk fill contendo PRG (Beautifil Bulk Restorative), que foi citotóxico para fibroblastos de camundongos L929 (AU)

Inula britannica flower total flavonoids inhibiting expression of RAGE in aging L929 cells induced by advanced glycation end products / 中草药

Objective To investigate the protective effect of Inula britannica flower total flavonoids (IBFTF) on aging L929 cells induced by advanced glycation end products (AGEs), and to explore the mechanism of the expression of receptor advanced glycation end products (RAGE). Methods The senescence L929 cells model was established by using 0.100 g/L AGEs for 48 h culture in vitro, and then different concentration of IBFTF (0.1, 0.2, and 0.4 g/L) was given to the treatment group for 6 h culture, and 0.1 g/L aminoguanidine hemisulphate (AG) was given to the positive group for another 6 h culture, and while blank group was cultured with common culture medium. Senescence aging index of β-galactosidase staining cell numbers and cell cycle analysis in L929 cells were measured. The levels of reactive oxygen species associated with oxidative stress in the cells, and aging indicators such as superoxide dismutase (SOD), malondialdehyde (MDA) were also examined. The fluorescent intensity of RAGE was detected by immunofluorescence. The expression of RAGE protein and mRNA was detected by Western blotting and qPCR, respectively. Results IBFTF significantly inhibited AGEs-induced L929 cells senescence and decreased RAGE protein and mRNA expression. Different concentrations of IBFTF could significantly increase the SOD activity and reduce the MDA content and eliminate the reactive oxygen species in aging L929 cells in a dose-dependent manner. Conclusion Protective effect of IBFTF on aging L929 cells induced by AGEs may be related to its effect on the surpressing the expression of RAGE.

Host-cell death pathways in L929 cells induced by Chlamydia muridarum infection / 中华微生物学和免疫学杂志

Objective To identify the host-cell death pathways (apoptosis, autophagy or necrosis) in L929 cells at the time point of 48 hours post infection (h.p.i.) with Chlamydia muridarum.Methods L929 cells were infected with Chlamydia muridarum at a multiplicity of infection (MOI) of 0.85 for 48 hours.Nuclear fragmentation was observed under fluorescence microscopy following staining L929 cells with DAPI (4′,6-diamidino-2-phenylindole).L929 cells were stained with propidium iodide (PI) plus Annexin Ⅴ and then analyzed by fluorescence-activated cell sorting (FACS) to clarify whether apoptosis or necrosis occurred after Chlamydia muridarum infection.L929 cells were transiently transfected with GFP-LC3 and observed under fluorescent microscopy to analyze cell autophagy.Western blot assay was performed to detect LC3 protein for further analysis of autophagy.Results Apoptosis was not induced in L929 cells by Chlamydia muridarum infection at 48 h.p.i.as no significant nuclear fragmentation was observed.Results of FACS showed that most cells died due to necrosis.Moreover, fluorescent dots of GFP-LC3 formed after infecting transfected L929 cells with Chlamydia muridarum.An increased ratio of LC3Ⅰ to LC3Ⅱ in the L929 cells infected with Chlamydia muridarum was detected by Western blot assay, indicating that autophagy occurred during Chlamydia muridarum infection.Conclusion Necrosis and autophagy rather than apoptosis are induced in L929 cells 48 hours after infection with Chlamydia muridarum.

Investigation of the cytotoxicity of thermoplastic denture base resins

PURPOSE: The purpose of this study was to investigate the in vitro cytotoxicity of thermoplastic denture base resins and to identify the possible adverse effects of these resins on oral keratinocytes in response to hot water/food intake. MATERIALS AND METHODS: Six dental thermoplastic resin materials were evaluated: three polyamide materials (Smile tone, ST; Valplast, VP; and Luciton FRS, LF), two acrylic materials (Acrytone, AT; and Acryshot, AS), and one polypropylene resin material (Unigum, UG). One heat-polymerized acrylic resin (Vertex RS, RS) was chosen for comparison. After obtaining extracts from specimens of the denture resin materials (Φ=10 mm and d=2 mm) under different extraction conditions (37℃ for 24 hours, 70℃ for 24 hours, and 121℃ for 1 hour), the extracts (50%) or serial dilutions (25%, 12.5%, and 6.25%) in distilled water were co-cultured for 24 hours with immortalized human oral keratinocytes (IHOKs) or mouse fibroblasts (L929s) for the cytotoxicity assay described in ISO 10993. RESULTS: Greater than 70% viability was detected under all test conditions. Significantly lower IHOK and L929 viability was detected in the 50% extract from the VP (70℃) and AT (121℃) samples (P < .05), but only L929 showed reduced viability in the 50% and 25% extract from LF (37℃) (P < .05). CONCLUSION: Extracts obtained from six materials under different extraction conditions (37℃, 70℃, and 121℃) did not exhibit severe cytotoxicity (less than 70% viability), although their potential risk to oral mucosa at high temperatures should not be ignored.

Construction of lentiviral vector specific for mouse B7-1 gene interference and study on silencing effects induced by lentivirus-mediated B7-1 RNAi / 中国免疫学杂志

Objective:To construct lentiviral vector specific for mouse B7-1 RNA interference and study lentivirus-mediated B7-1 gene silencing effects in L929 fibroblast cells.Methods:Three candidate sequences for B7-1 RNAi selected from coding sequence of mouse B7-1 transcription were used to design short hairpin RNA ( shRNA ) templates and then cloned into lentiviral expression plasmid followed with correctness identification of inserted sequence by DNA sequencing.Recombinant lentivirus were prepared by co-transfecting lentiviral expression vector and packaging plasmids into 293T cells.Then the resulting culture supernatant containing infectious lentiviral particles was pooled and centrifuged via ultra-centrifugation.Infectious titer of the preparations was determined by detecting the expression of GFP in 293T cells after transfected by lentivirus.Cultured L929 cells were transfected with lentivirus to deter-mine transduction efficiency and silencing efficacy of B7-1 expression by flow cytometry.Transducted L929 cells were then screened using puromycin to generate stable cell clones followed by flow cytometry analysis of GFP and B7-1 expression.A mixed reaction system consisting of stable B7-1 silencing L929 cells and mouse splenic T cells was used to analyze ability of the established cell line to trigger T cells proliferation.Results: Lentiviral expression vector for mouse B7-1 RNAi was correctly constructed with inserted sequences as designed.Recombinant RNAi lentivirus were prepared with titers ranging (3-5) ×108 TU/ml and efficacy to mediate GFP transgene expression and B7-1 silencing.B7-1 expression and the ability to trigger T cells proliferation of stable L929 cells were suppressed significantly ( P<0.05 ).Conclusion: We generated lentiviral vector specific for mouse B7-1 RNAi with high performance of transduction efficiency as well as B7-1 silencing efficacy and the recombinant RNAi lentivirus can mediated stable B7-1 gene silencing in L929 cells and inhibition of T cells proliferation induced by B7-1/CD28 co-stimulatory signal.

The effect of barium titanate coating on the proliferation of mouse fibroblast L929 cells tested by MTT method / 实用口腔医学杂志

Objective:To investigate the effect of the leaching liquids of the pure titanium porcelain crowns with barium titanate coating on the proliferation of L929 cells,and to evaluate its cytotoxicity level.Methods:The L929 ceils were cultured in vitro with leaching liquids of titanium porcelain specimens with barium titanate coating (group A),and titanium porcelain specimens(group B) for 1,3 and 5 days respectively.RPMI1640 containing 10％ fetal bovine serum and 1％ phenol was served as the negative(group C) and positive control group(group D),respectively.MTT method was used to test the effects of barium titanate coating on the proliferation of mouse fibroblast L929 cells,the cytotoxicity of the 4 groups was graded.Results:L929 cells of the group showed normal morphology and vigorous growth except group D.During the whole experiment,the absorbance values of group A was greater than that of group C(P ＜0.05).The cytotoxic gradation of group A grade 0.Conclusion:Titanium porcelain specimens with barium titanate coating has a good cytocompatibility.

Clarias batrachus collagen extract increases fibroblast cell adhesion, migration and proliferation.

Collagen is an extracellular matrix protein with great importance in biomedical application. The search for collagen from various sources is intensified especially from marine source. This study was carried out to extract collagen from a Malaysian local fresh water fish, Clarias batrachus and characterized its biomedical potential In vitro. Collagen was extracted from C. batrachus skin using acetic acid method and identified using SDS-PAGE. MTT assay was performed to determine the effect of coated collagen on cell adhesion and proliferation of L929 skin fibroblast cells. Additionally, scratch assay was performed to examine the effect of collagen coating on fibroblast cell migration. Result showed that collagen extracted from C. batrachus was made up of collagen type I, which consists of two α chains (α-1 and α-2) and β chain. At 100 μg/cm2 density, collagen coating significantly increased fibroblast cell adhesion, proliferation and migration compared to negative control (p< 0.05). As a conclusion, collagen extracted from C. batrachus increased cell adhesion, proliferation and migration of fibroblast cells and has potential to be used as an alternative source of collagen.

Effect of overexpression of asporin on regulations of TGF- β 1 and Col2α1 in L929 cells / 实用医学杂志

Objective To establish the L929 cell line with high expression of asporin ,and to study the effect of asporin on the expressions of TGF- β1 and Col2α1 in mouse fibroblast L929. Methods Asporin cDNA was amplified from mouse mandible tissue by RT-PCR,then was inserted into the eukaryotic expression plasmid pcDNA3.1(-). The recombinant plasmid pcDNA3.1(-)-ASPNIII was transfected into the mouse fibroblast cell line L929, followed by G418 treatment. RT-PCR and Western blot assays were used to screen the stable, asporin high expressing L929 cell line.The effect of overexpression of asporin on the regulations of TGF-β1 and Col2α1 was further studied. Results The stable, aspori high expressing n L929 cell linewas successfully established. Results of RT-PCR and Western blot assays showed that overexpression of asporin could effectively inhibit the expressions of TGF-β1 and Col2α1. Conclusion Enforced expression of asporin can inhibit the expression of TGF-β1 and Col2α1 in L929 cells.

Effect of aging on tear strength and cytotoxicity of soft denture lining materials; in vitro

PURPOSE: The aim of this in vitro study was to evaluate the effect of aging on the tear strength and cytotoxicity of four soft denture lining materials. MATERIALS AND METHODS: Four commonly used soft denture lining materials, (Coe-Comfort(TM) GC America Inc., Alsip, IL, USA; Coe-Soft(TM) GC America Inc., Alsip, IL, USA; Visco-gel Dentsply Caulk Milford, DE, USA; and Sofreliner Tough M Tokuyama Dental Corporation Tokyo, Japan) were selected. Sixty trouser-leg designed specimens per lining material were fabricated using a stainless steel mold for tear strength testing. The specimens were divided into non-thermocycling and 1000-, and 3000- thermocycling groups. For the cytotoxicity test, twenty-four disk shaped specimens per material were fabricated using a stainless steel mold. The specimens were soaked in normal saline solution for 24 h, 48 h and 72 h. Cytotoxicity was measured by XTT assay in L929 mouse fibroblasts. Data were analyzed by two way analysis of variance and Dunnett's test (P<.05). RESULTS: Before thermocycling, Sofreliner Tough M (10.36 +/- 1.00 N) had the highest tear strength value while Coe-Comfort(TM) (0.46 +/- 0.10 N) had the lowest. After 3000 cycles, Sofreliner Tough M (9.65 +/- 1.66 N) presented the highest value and Coe-Comfort(TM) (0.42 +/- 0.08 N) the lowest. Sofreliner Tough M, in all incubation periods was the least toxic with significant differences compared to all other materials (P<.05). Coe-Comfort(TM), Coe-Soft(TM), and Sofreliner Tough M did not show any significant differences within their material group for all incubation periods. CONCLUSION: This in vitro study revealed that aging can affect both the tear strength and cytotoxicity of soft denture materials depending on the composition.

Influence of PPAR -γligand on radiation - induced PAI - 1 and TGF -βmRNA in fibroblast cells / 中华放射肿瘤学杂志

Objective To observe the influence of peroxisome proliferator activated receptor-γligand (PPAR-γ, pioglatazone) on expression of PAI-1 and TGF-β mRNA and proliferation in fibroblast cells before and after X-ray radiation, and to study the effect of PPAR-γon normal cells during radiation induced fibrosis process. Methods RT-PCR method was used to measure PPAR-γgene expression in L929 cells.After X-ray irradiation of 10 Gy,4 Gy or 2 Gy, the expressions of PAI-1 and TGF-β mRNA in mouse lung fibroblast cells (L929) were measured using RT-PCR. After X-ray irradiation and pioglatazone treatment,the influence of pioglatazone on PAI-1 and TGF-β was measured using RT-PCR method. MTT method was used to test cell proliferation after the treatment of irradiation and pioglatazone. Results PPAR-γ mRNA expression was observed in L929 cells. Expression of PAI-1 and TGF-β mRNA reached the highest level 483.40,P =0. 090) ). At 48 h after the treatment of pioglatazone and 10 Gy radiation, pioglatazone decreased 0. 36, 0. 34 and 0. 32( F = 3.90, P = 0. 040) ). The inhibitory effect was significantly increased when L9292. 50,P =0. 005)). Conclusions X-ray irradiation can increase the expression of PAI-1 and TGF-β in L929 cells. Pioglatazone can decrease the expression of radiation-induced PAI-1 and TGF-β, and restrain the fibroblast proliferation.

Lack of Effect of Dexamethasone on Growth of Orientia Tsutsugamushi Gilliam in Mouse L929 Cells

PURPOSE: Previous studies and our own clinical experience suggest that concurrent corticosteroid treatment for severe rickettsial disease with multiorgan failure may improve the clinical course or reduce mortality. However, the use of corticosteroids as adjunctive treatment for rickettsial diseases is controversial. We attempted to determine the influences of corticosteroid on the growth of Orientia tsutsugamushi in vitro to justify and evaluate the clinical applicability of corticosteroid in rickettsial disease. MATERIALS AND METHODS: L929 cells were infected with Orientia tsutsugamushi Gilliam. Dexamethasone was added to the cells at final concentrations of 10(1) and 10(7) pg/mL. Cultures were incubated at 35degrees C and processed for flow cytometry on the 6th day after addition of dexamethasone. RESULTS: Observation on the 6th day after treatment with dexamethasone in infected cultures revealed that there was no difference in fluorescence intensity among the treatment wells. Treatment of the cells with dexamethasone at concentrations of 10(1) and 10(7) pg/mL showed no influence on the growth of Orientia tsutsugamushi. CONCLUSION: Our results to show that isolated corticosteroid does not enhance the replication of Orientia tsutsugamushi in vitro. Concurrent use of anti-inflammatory or immunosuppressive doses of corticosteroids in conjunction with antibiotics may not have detrimental effects on the course of scrub typhus.

Biological activity of sea anemone proteins: II. Cytolysis and cell line toxicity.

Potent cytolytic activity was exhibited by proteins extracted from three sea anemones viz. Heteractis magnifica, Stichodactyla haddoni and Paracodylactis sinensis by affecting the red blood corpuscles (RBC) and the mouse fibroblast cell line (L929) and leukemia cell line (P388). Crude toxin of all the three anemone species induced spontaneous hemolysis of chicken, goat and human erythrocytes. The crude toxin of H. magnifica (0.98 mg/ml) elicited hemolysis at levels of 4096, 512 and 4096 HU (hemolytic unit) in chicken, goat and human erythrocytes respectively. Subsequently, the crude toxin of S.haddoni (0.82 mg/ml) exhibited a hemolytic activity of 256, 128 and 512 HU and that of P. sinensis (0.60 mg/ml) had a hemolytic activity of 128, 4096 and 512 HU. Most of the partially purified proteins of these anemones also exhibited the activity against the three different erythrocytes. The viability of L929 and P388 was adversely affected on adding the crude toxins. The symptoms of toxicity shown by the cells were rounding, lysis and detachment from the substratum. These effects were the least in S. haddoni, as compared to those the crude toxins of the other two species. Inhibition of growth of L929 exhibited by the toxin of the three species ranged between 61.08 and 93.38%. Similarly, inhibition of the growth of P388 ranged between 51.32 and 86.16%. The present investigation reveal the cytotoxic nature of anemone toxins.

Evaluation of Brazilian medical devices using agar diffusion cytotoxicity assay / Avaliação de dispositivos médicos brasileiros utilizando o ensaio de citotoxicidade pela difusão em ágar

Over the last decades, governmental actions and mechanisms created to protect consumer rights have been linked to a growing effort to guarantee the quality and reliability of products. Samples of condoms (latex), medical devices and blood bags (PVC - polyvinyl chloride) have been tested using the agar diffusion assay. This assay evaluates the cytotoxicity induced by biomaterials by measuring the biological reactivity of mammalian cell cultures in contact with these materials. PVC is used in the production of medical devices because of its specific properties, such as flexibility, obtained after the addition of plasticizers (phthalates), which can cause toxicity even at low doses. Latex is a natural elastomer used for surgical gloves and condoms with a formulation that includes dispersion of liquid latex and chemicals, such as antioxidants and a vulcanizing accelerator, both of which are able to induce cytotoxicity. Samples were analyzed by the National Institute of Quality Control in Health - INCQS of the Oswaldo Cruz Foundation (Fiocruz) in accordance with the governmental sanitary surveillance actions on respect to the quality control. We observed an increase in the quality of the products in relation to the results of the agar diffusion assay during the period between 2000 and 2007. This situation, together with other actions, reflects in an improvement in the quality of products that can be translated in the health of the population.

Durante as últimas décadas, a disseminação de ações governamentais e os mecanismos criados para proteger os direitos dos consumidores se associaram em crescentes esforços para garantir a qualidade e confiabilidade dos produtos. As amostras de preservativos (látex), dispositivos médicos e bolsas de sangue (PVC - cloreto polivinílico) foram testadas utilizando o ensaio de difusão em ágar. O teste avalia a citotoxicidade induzida por biomateriais, medindo a reatividade biológica de culturas de células de mamífero em contato com tais materiais. PVC é utilizado na produção de dispositivos médicos, devido às suas propriedades específicas, incluindo flexibilidade, obtida após a adição de plastificantes (ftalatos) que podem apresentar toxicidade mesmo em doses baixas. Látex é um elastômero natural utilizado em luvas cirúrgicas e preservativos que na sua formulação inclui a dispersão do látex líquido e de substâncias químicas, como antioxidantes e um acelerador de vulcanização, ambos capazes de induzir citotoxicidade. As amostras foram analisadas pelo Instituto Nacional de Controle de Qualidade em Saúde - INCQS da Fundação Oswaldo Cruz (Fiocruz) em atendimento às ações governamentais de vigilância sanitária no tocante ao controle de qualidade. Um aumento na qualidade dos produtos em relação aos resultados no ensaio de difusão em ágar foi observado no período compreendido entre 2000-2007. Esta situação, dentre outras ações, reflete uma melhoria na qualidade dos produtos que pode ser traduzida em saúde para a população.

Evaluation of the Extraction Method for the Cytotoxicity Testing of Latex Gloves

In this study, the cytotoxicity of medical latex gloves to cultured L-929 cells was determined using various extraction conditions. According to the extraction time and temperature, three types of extraction conditions were used: 1) 24 h at 37 degrees C; 2) 72 h at 37 degrees C; 3) 72 h at 50 degrees C. Also, four different extraction vehicles were used, namely, distilled water (DW), 9 g/l sodium chloride (saline) in DW, and culture media with or without serum. Under the above-mentioned conditions, the samples were extracted and then 2-fold serially diluted in the concentration range 3.13 - 50%. When extracted with either DW or saline for 24 h or 72 h at 37 degrees C, only 50% diluted samples showed distinct cytotoxicity to L-929 cells. Moreover, no cytotoxic potentials were observed when gloves were extracted with DW or saline at 50 degrees C for 72 h. Cytotoxicity was markedly greater when gloves were extracted with culture medium, irrespective of the presence of serum in the medium. These results suggest that optimal extraction conditions should be established for the cytotoxicity evaluations of biomaterials and medical devices.

Exogenous CCN1 promotes proliferation and migration of radiation-injured L929 cells / 第三军医大学学报

Objective To study the role of Cysteine-rich 61 ( Cyr61/CNN1) in repair of combined injury by observing whether exogenous CCN1 promotes the proliferation and migration of radiation-injured L929 cells. Methods A radiation model of L929 cells was induced by ? ray at a dose of 4 Gy. The irradiated L929 cells were cultured in a medium containing 2 ml adenovirus plasmids of CCN1 or RFP at 37 ℃ in an atmosphere containing 5% CO2,which served as a CCN1 group and a RFP group,respectively. Irradiated L929 cells cultured in a blank control medium served as a blank control group. Effects of CCN1 on proliferation and migration of radiation-injured L929 cells were detected by MTT assay,plate colony formation assay,cell cycle analysis,and scratch test of wound healing. Results The proliferation and colony formation rates of L929 cells cultured in a medium containing CCN1 were significantly higher than in RFP and control groups [colony formation rate:( 34. 4 ?3. 6) % vs ( 24. 5 ?2. 9) % and ( 29. 5 ?3. 5) %,P

Effect of Paclitaxel on the beta-actin, Fibronectin, Laminin and Fine Structure in HeLa and L929 Cells / 대한해부학회지

The aim of this investigation was to elucidate the changes in the cytoplasmic distribution of beta-actin, fibronectin, and laminin through mainly the morphological changes occurring in HeLa and L929 cancer cell treated with paclitaxel. Whether or not paclitaxel regulates cell proliferation was assessed with MTT assay. Possible influence on the distribution of beta-actin, fibronectin, and laminin in these cells was confirmed with immunocytochemistry and analySIS Auto software program. The changes in cell morphology were observed under inverted and electron microscope. The MTT assay showed that 1 micrometer and 10 micrometer concentrations of paclitaxel inhibited HeLa cell growth approximately by 20% to 80% and L929 cell by 27% to 44% in a dose- and time-dependent manner. The distribution of these proteins was changed from the condensed around nucleus and strong reaction to the weak throughout cytoplasm. The morphological changes indicated that paclitaxel changes the location or number of protein synthesis apparatus: damages of RERs, Golgi complex, and increase of heterochromatin. These data suggest that the growth inhibition and morphological changes of tumor cells induced by paclitaxel might be modulated by the rearrangement and decreased production of beta-actin, fibronectin, and laminin in cytoplasm.

Effect of Ni-Cu Thermoseeds on L-929 Cells and Muscle Tissues in Rabbits / 中国微创外科杂志

Objective To study the in vitro heating ability of Ni-Cu thermoseeds and their effect on the rabbit liver cells and tissues. Methods The temperature of rabbit liver tissues were monitored under an alternating magnetic field.MTT assay was used to evaluate the in vitro cytotoxicity of the extra-liquid of the Ni-Cu thermoseeds;Hemolytic test was carried out to estimate its blood toxicity;and muscular implantation test was employed to determine the levels of its tissue toxicity.Results The thermoseeds used in this experiment showed a high heating ability in alternating magnetic field in vitro.MTT assay showed that the toxicity of the material on mouse fibroblast(L-929) cell lines was 1 degree,which means non-cytotoxic.Hemolytic test revealed a hemolysis rate(HR) of 3.25%(less than 5%),showing that the thermoseeds had no hemolytic reaction.Muscular implantation test showed different levels of inflammatory reaction in the muscle tissues.Conclusion Thermoseeds induced heating in alternating magnetic field can achieve an appropriate temperature,and the gilded thermoseeds have a high biocompatibility with 1 degree cytotoxicity without leading to hemolytic reaction.

Magneto-heating Effect and Cytotoxicity of Carbonyl Iron Powder in Arterial Embolization Hyperthermia / 中国微创外科杂志

Objective To evaluate the magneto-heating effect and cytotoxicity of the carbonyl iron powder as a feasibility for arterial embolization hyperthermia. Methods Different doses of carbonyl iron powder suspensions were prepared in vitro(10 mg/ml,100%;10 mg/ml,50%;or 64 g/L phenol solutions),and heated for 20 minutes in an alternating magnetic field(49.9,79.9,and 110.2 Oe).The influences of the doses of suspensions and currency of magnetic field on the heating effect were observed.Meanwhile,mouse fibroblast L-929 cells were cultured with the suspensions for 2,4,or 7 days.The morphology and relative growth rate(RGR) of the cells were determined by microscopy and MTT assay.The cytotoxicity of the suspensions was then classified. Results The heating ability of the carbonyl iron powder increased with the suspension concentration and the strength of the magnetic field.A optimal therapeutic temperature was achieved at 110.2 Oe with 60 mg/ml carbonyl iron powder suspension.The L-929 cells showed normal morphology after been treated by the carbonyl iron powder(10 mg/ml 100% solution and 50% solution) for 2,4 and 7 days with the 0-1 degree cytotoxicity.Conclusion The carbonyl iron powder has good heating effect under the alternating magnetic field,and is compatible with the tested cells.

The role of negative co-stimulation molecule PD-L in the T-cell immune response against murine tumor cell line L929 / 中国免疫学杂志

Objective:To investigate the possible roles of the negative co-stimulation molecule PD-L(ligand) in the T-cell mediated immune response against tumor.Methods:Flow cytometric analysis was used to examine murine tumor cell line L929 expresses PD-L(L1 and L2).Anti-PD-L blocking monoclonal antibodies combined with injection i.p.of irradiated L929 into C57BL/6 mice was employed to sensitize the T cells of the animals.2 weeks after sensitization,mice were sacrificed,and splenocytes were prepared to perform the examinations of T cell proliferation,cytotoxic T cells(CTL) activity,and apoptosis through in vitro coculture with L929 in the presence of blocking PD-L antibodies.Results:The expression of PD-L1 by L929 was detectable,whereas there was no expression of PD-L2 on these cells.Application of blocking antibody against PD-L1 or PD-L2 together with irradiated L929 cells in the process of in vivo sensitization as well as in vitro stimulation,it was shown that blockade of PD-L1 significantly enhanced the T cell proliferation induced by L929 cells and the CTL activity against L929,evidenced by the increased apoptosis and death rate of L929 cells.In control,blockade of PD-L2 had small effects on these terms.Conclusion:The negative co-stimulation molecule PD-L1 plays a role in the escape of tumor cells from host T-cell mediated tumor immunity.Therefore,blockade of PD-L1 has potential significance for tumor immunotherapy.

Mechanism of rapid effects of steroids on glycine uptake in L_(929) cells / 中华内分泌代谢杂志

Objective To investigate the role of steroids on the intracellular signal transduction mechanism of nongenomic effects for L 929 cells to uptake glycine. Methods The labeled glycine in L 929 cells was measured by scintillation technique. After L 929 cells were incubated with labeled glycine and steroid and/or other chemical reagents, the effects of steroids and their mechanism were determined. Results Corticosterone, aldosterone, estradiol, dexamethone and hydrocortisone inhibited glycine uptake by L 929 cells to various extents. There was no substantial difference between the effects of bovine serum album conjugated corticosterone and corticosterone 21 sulfate on glycine uptake. The inhibitor of G protein, GDP ? S, could partially block the effects of corticosterone and aldosterone. The inhibitor of phospholipase C, neomycine, did not inhibit the effect of corticosterone. The inhibitor of protein kinase C, Chelerythrine, partially blocked the effect of corticosterone. The activator of protein kinase C (phorbol 12 myristate, 13, acetate) seemed to imitate the effect of corticosterone. The activator of cAMP, Forskolin, and the inhibitor of protein kinase A, H 89 , blocked the effect of corticosterone. Conclusion The rapid inhibitory effects of steroids on glycine uptake in L 929 cells are nongenomic, and their signal transduction is through the pathway of G protein protein kinase C.