The present study evaluated the effect of aflatoxin B1 (AFB1) and fumonisin B1 (FB1) either alone, or in association, on rat primary hepatocyte cultures. Cell viability was assessed by flow cytometry after propidium iodine intercalation. DNA fragmentation and apoptosis were assessed by agarose gel electrophoresis and acridine orange and ethidium bromide staining. At the concentrations of AFB1 and FB1 used, the toxins did not decrease cell viability, but did induce apoptosis in a concentration and time-dependent manner.

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Mice bearing large (greater than or equal to 3 g) metastatic and nonmetastatic Lewis lung carcinoma (LLC) tumors were studied to determine if the tumor variants differentially induced bone marrow versus splenic hematopoiesis and the appearance of hematopoiesis-associated immune suppressor cells. The metastatic LLC-C3 and nonmetastatic LLC-C8 tumors were equal in their stimulatory effects in vivo on both the number of bone marrow myeloid progenitor cells (CFU) and the appearance of bone marrow immune suppressor cells. In contrast, the tumor variants differed in their effects on the spleen, with the metastatic tumors causing a more pronounced increase in the number of nucleated cells and CFU, a reduced blastogenic responsiveness to concanavalin (Con-A), and an increased suppressor cell activity than nonmetastatic LLC-C8 tumors. The splenic suppressor cells of mice bearing large LLC-C3 tumors resembled the bone marrow suppressor cells which we previously described (Young et al.: Cancer Res. 47, 100, 1987) in that they were nonadherent to nylon wool, sensitive to treatment with L-leucine methyl ester, insensitive to treatment with complement and Thy-1.2, MG-1.2, asialo-GM1, or anti-IgM antibodies, and mediated their suppression through a mechanism which was only partially indomethacin sensitive. The stimulatory effects on hematopoiesis and suppressor cells by the LLC variant tumors may have been mediated by the tumor-derived colony stimulating factor (CSF) activities. Bone marrow cell proliferation and colony formation were stimulated in vitro by culture supernatants of metastatic LLC-C3 cells and, to a lesser degree, of nonmetastatic LLC-C8 cells. These colony-stimulating factor (CSF)-containing supernatants also induced normal bone marrow cells to become immune suppressive. In contrast, supernatants of only LLC-C3 cells, and not of LLC-C8 cells, stimulated in vitro growth of splenic CFU from LLC-C3-bearing mice; spleen cells from normal mice and from LLC-C8 bearers were unresponsive to supernatants of the LLC variants. These results suggest that CSF produced by either the metastatic LLC-C3 or the nonmetastatic LLC-C8 tumors could concurrently stimulate bone marrow hematopoiesis and the appearance of bone marrow suppressor cells. However, the metastatic LLC-C3 tumor cells, and not the nonmetastatic LLC-C8 cells, could also cause expansion of progenitor cells and hematopoiesis to the spleen and, consequently, induce the appearance in the spleen of hematopoiesis-associated immune suppressor cells.

One of the currently most important fungi in stored grains is Aspergillus flavus, which produce aflatoxins. This fungus can grow on diverse substrates and represents a serious public health and animal nutritional problem. Therefore, the study of techniques that can be applied to the control of aflatoxins is of great importance. The objective of the present study was to determine the effects of gamma radiation on the growth of Aspergillus flavus Link and on degradation of aflatoxin B1 and B2 (AFB1 and AFB2) at a relative humidity of 97 -99% and a water activity (Aw) of 0.88-0.94. Samples of corn grains were irradiated using a cobalt 60 source emitting gamma rays at doses of 2, 5 and 10 kGy. Irradiation was found to be effective in reducing the number colony-forming units of A. flavus, per gram, in the corn samples analyzed. In addition, the fluorescent viability test (fluorescein diacetate and ethidium bromide) revealed a decrease in the number of viable cells with increasing irradiation doses and three different fluorescence patterns. Furthermore, irradiation induced a partial reduction in AFB 1 and AFB 2 levels at the doses of 2 and 5 kGy, whereas complete degradation of aflatoxins was observed in the assay employing 10 kGy.

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Methylene Blue (MB) has been widely used in antimicrobial Photodynamic Therapy (aPDT), however, the mechanisms of action (Type I or Type II) are defined by its state of aggregation. In this sense, the identification of the relationships between aggregation, the mechanisms of action and the effectiveness against microorganisms, as well as the establishment of the means and the formulations that may favor the most effective mechanisms, are essential. Thus, the objective of this study was to assess the in vitro aPDT efficacies against Candida albicans, by using MB in vehicles which may influence the aggregation and present an oral formulation (OF) containing MB, to be used in clinical aPDT procedures. The efficacy of MB at 20 mg L-1 was tested in a range of vehicles (water, physiological solution - NaCl 0.9%, phosphate saline buffer - PBS, sodium dodecyl sulfate 0.25% - SDS and urea 1 mol L-1) in a C. albicans planktonic culture, when using 4.68 J cm-2 of 640 ± 12 nm LED for the irradiations, as well as 5 minutes of pre-irradiation time, together with measuring the UFC mL-1. Based upon these analyses, an OF containing MB in the most effective vehicle was tested in the biofilms, as a proposal for clinical applications. When comparing some of the vehicles, sodium dodecyl sulfate was the only one that enhanced an MB aPDT efficacy in a planktonic C. albicans culture. This OF was tested in the biofilms and 50 mg L-1 MB was necessary, in order to achieve some reduction in the cell viabilities after the various treatments. The light dosimetries still need further adaptations, in order for this formulation to be used in clinical applications. The present research has indicated that the development of this formulation for the control of MB aggregations may result in more effective clinical protocols.

No abstract

RESUMOA segregação adequada dos Resíduos de Serviços de Saúde (RSS) reduz a contaminação dos resíduos comuns, os riscos à saúde ocupacional e permite recuperar os materiais recicláveis. A segregação eficiente depende do treinamento e da conscientização dos colaboradores envolvidos na geração dos RSS. Portanto, o objetivo do presente estudo foi desenvolver um modelo de avaliação, capacitação e mensuração da segregação dos resíduos comuns, em especial do papel reciclável, no setor administrativo do Hospital Cândido Fontoura, localizado na cidade de São Paulo. Foi realizado o acompanhamento da rotina de manejo dos resíduos comuns e do papel reciclável, de junho a outubro (2014). Foi realizada a capacitação por meio de palestras e orientação diária para a sensibilização dos colaboradores sobre a importância do descarte adequado dos resíduos. Os resultados foram obtidos através da segregação e pesagem dos resíduos de papel reciclável e resíduos comuns. Foram consideradas três amostras: antes da sensibilização (Antes); depois da sensibilização (Depois); com monitoramento diário no setor (Acompanhado). O período de avaliação por amostra foi de nove dias (n = 9). Foi aplicado o teste estatístico (análise de variância) Kruskal-Wallis (α < 0,05) para os pesos das amostras, as quais foram consideradas significativamente diferentes (p = 0,0034). A amostra Antes (6,2 ± 2,9 kg) apresentou maior massa. Não houve diferença significativa entre massas das amostras Após (3,0 ± 1,7 kg) e Acompanhado (2,8 ± 1,5 kg), sendo consideradas semelhantes. O montante de papel reciclável evoluiu inversamente ao resíduo comum, de 3,7 ± 0,2 kg (Antes) para 6,7 ± 3,1 kg (Acompanhado), demonstrando a efetividade e correta reciclagem de RSS.Palavras-chave: Resíduos de Serviços de Saúde, reciclagem, resíduo comum, papel reciclável.