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Glass-ionomer cements are widely used in dentistry as restorative materials and adhesives for composite restorations. A number of genotoxicity studies have been conducted using these materials with results conflicting so far. Thus, the approach was aimed to look at the genotoxic and cytotoxic potential of three different glass-ionomer cements available commercially (Ketac Cem, Ketac Molar and Vitrebond) by the single cell gel (comet) assay and trypan blue exclusion test, respectively. For this, such materials were exposed to mouse lymphoma cells in vitro for 1 h at 37 degrees C. Data were assessed by Kruskall-Wallis non-parametric test. The results showed that all powders assayed did not show genotoxic effects. On the other hand, the liquid from Vitrebond at 0.1% dilution caused an increase of DNA injury. Significant statistically differences (P < 0.05) in cytotoxicity provoked by all powders tested were observed for exposure at 1,000 micro g mL(-1) concentration and 100 micro g mL(-1) for Ketac Molar. With respect to liquids of glass-ionomer cements evaluated, the major toxic effect on cell viability was produced at 1%, beginning at the dilution of 0.5% for Vitrebond. Taken together, these results support the notion that some components of glass-ionomer cements show both genotoxic and cytotoxic effects in higher concentrations.

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Chloroform and eucalyptol are widely used in clinical dentistry as gutta-percha solvents. However, these compounds may represent a hazard to human health, especially by causing injury to genetic apparatus and/or inducing cellular death. In this study, the genotoxic and cytotoxic potentials associated with exposure to chloroform and eucalyptol were assessed on mouse lymphoma cells in vitro by the single cell gel (comet) assay and trypan blue exclusion test, respectively. Both gutta-percha solvents proved to be cytotoxic at the same levels in concentrations of 2.5, 5 and 10 microL/mL (p<0.05). On the other hand, neither of the solvents induced DNA breakage. Taken together, these results suggest that although both tested compounds (chloroform and eucalyptol) are strong cytotoxicants, it seems that they are not likely to increase the level of DNA damage on mammalian cells.

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Recently, regular and white mineral trioxide aggregate (MTA) are being used in Dentistry as retrofilling materials. Genotoxicity and cytotoxicity tests form an important part of cancer research and risk assessment of potential carcinogens. Thus, the goal of this study was to examine the genotoxicity and cytotoxicity of regular and white MTA in vitro by the single cell gel (comet) assay and trypan blue exclusion test, respectively. Mouse lymphoma cells were exposed to two presentation forms of MTA at final concentrations ranging from 1 to 1,000 microg/mL for 3 h at 37 degrees C. The results showed that both compounds tested did not produce genotoxic effects at all concentrations evaluated. Likewise, no statistically significant differences (p > 0.05) were observed in cytotoxicity. Taken together, our results suggest that regular and white MTA are not genotoxins and are not able to interfere in cellular viability as assessed by single cell gel (comet) assay and trypan blue assay, respectively.

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The immunomodulatory effect of hydrosoluble extracts of four Chilean Cyttaria species (Discomycetes, Fungi) was assessed in mice with L5178Y lymphoma. Oral administration of 100 mg extract per day for 7 days enhanced the percentual phagocytosis and phagocytosis index in animals receiving Cyttaria berteroi, Cyttaria darwinii, Cyttaria espinosae and Cyttaria harioti extracts. Differences in the digestion index were observed in mice treated with C. darwinii and C. berteroi. In the delayed-type hypersensitivity model, only C. harioti was able to modify the immune response. The results suggest that intake of Cyttaria can improve the immune system of consumers.

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Electromagnetic fields (EMFs) have been associated with impairing health. There are data that associate EMFs exposure to incidence of cancer, but there are conflicting results between epidemiological and laboratory studies. Similarly studies on the effect of EMF on the immune system have produced variable results. In the present study, we evaluated the acute effects of 60 Hz EMFs exposure at 1.0 mT, on proliferation of murine thymic lymphocytes, production of nitric oxide and phagocytosis of Candida albicans by peritoneal murine macrophages, as well as the effect of 8 h/day of EMF exposure during 6 days on proliferation of murine lymphoma L5178Y-R cell growth. We observed that exposure to EMF did not alter lymphocyte and macrophage functions, and did not affect in vitro cell growth of the murine lymphoma cell line L5178Y-R.

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Tan y Kunkel demostraron en diversos tejidos humanos y animales un antigeno nuclear que denominaron Sm, el cual reacciona de manera especifica con aproximadamente 30 por ciento de los sueros de enfermos de lupus eritematoso generalizado. En el momento actual la fuente de obtencion de dicho antigeno para fines comerciales es el timo de conejo, del cual se prepara un extracto acetonico. En este estudio se demostro que las celulas del linfoma murino L5178Y, de origen timico, contienen dicho antigeno en abundancia el cual se extrae facilmente con solucion salina amortiguada cuando las celulas han recibido previamente un choque termico. Ademas de informarse por primera vez la presencia de dicho antigeno en un tejido neoplasico animal, se propone el metodo aqui empleado como fuente de obtencion del antigeno Sm, dado que su extraccion es facil, de bajo costo y de alto rendimiento

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Se investigo si la inmunizacion con celulas del linfoma murino L5178Y inactivadas por radiacion induciria una reaccion inmunitaria de rechazo hacia las celulas intactas de ese linfoma. La dosis de radiacion necesaria para inactivar las celulas del linfoma fue de 6,000 rads, suministradas por un emisor de 60 Co. Se inmunizaron 26 ratones BALB/C con cuatro inyecciones por via intraperitoneal una cada ocho dias de 5x10 (6) celulas L5178Y radiadas. Diez dias despues se les aplico por la misma via una dosis de prueba de 5x10 (7) celulas L5178Y intactas. Los testigos fueron otros 20 ratones no inmunizados que recibieron el mismo inoculo de celulas L5178Y. Los ratones se sacrificaron ocho dias despues, y se evaluo el crecimiento por el numero de celulas L5178Y producidas. Los ratones testigos desarrollaron un promedio de 10.05+/-0,02 x 10 (8) celulas tumorales. Los ratones inmunizados con las mismas celulas radiadas desarrollaron 25.20+/-0.03 x 10 (8)celulas L5178Y (p <0.001). Estos resultados mostraron que las celulas del linfoma murino L5178Y inactivadas por radiacion no indujeron una reaccion de rechazo hacia las mismas celulas viables, sino que la inmunizacion con ellas causo un incremento del desarrollo tumoral en los ratones inmunizados

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Location of neoplasia specific tumoral antigens (ANE) were investigated in L5178Y murine cells. Cells were treated by means of concanavalin A (CoA), Vibrio cholerae neuraminidase (NVC) or a combination of both (Coa-NVC) and were inactivated by 6,000 rad irradiation. With 5 x 10(6) treated cells four groups, 15 mice in each group of the BALB/c strain were immunized weekly and 10 days latter immunity to L5178Y lymphoma cells was tested by means of intraperitoneal inoculation of 5 x 10(7) intact, viable L5178Y cells. None of the mice immunized with concanavalin A treated and irradiated cells developed the inoculated lymphoma. However all mice immunized with cells treated with CoA or CoA-NVC developed a lymphoma. Electron microscopy studies of normal L5178Y cells, irradiated or treated with NVC showed the exterior cell coating or glycocalix that was absent in those treated with CoA or CoA-CoA-NVC. These results allowed us to conclude that ANE of L5178Y cells susceptible to modification by NVC as if to induce an immunologic rejection response are located in the glycocalix of these cells.

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Radiosensitivity of L5178/ murine lymphoma was studied in vivo by means of Co60 pump radiations. The dosage necessary to inactivate these cells was from 5,000 to 6,000 rads applied in an only dose. Doses under 2,000 to 4,000 rads only achieved partial inactivation, proportional to dosage applied. 100 to 1600 rad doses did not produce adverse effects on these cells. Lethal dose for carrier mice was from 800 to 1200 rads applied in one dose only or a total of over 600 rads applied in 100 rad daily sessions. High radioresistance of lymphoma did not allow destruction of all neoplastic cells in vivo for, before this occurred carrier mice died.

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