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SUMMARYDNA damage can activate apoptotic and non-apoptotic forms of cell death; however, it remains unclear what features dictate which type of cell death is activated. We report that p53 controls the choice between apoptotic and non-apoptotic death following exposure to DNA damage. In contrast to the conventional model, which suggests that p53-deficient cells should be resistant to DNA damage-induced cell death, we find that p53-deficient cells die at high rates following DNA damage, but exclusively using non-apoptotic mechanisms. Our experimental data and computational modeling reveal that non-apoptotic death in p53-deficient cells has not been observed due to use of assays that are either insensitive to cell death, or that specifically score apoptotic cells. Using functional genetic screening – with an analysis that enables computational inference of the drug-induced death rate – we find in p53-deficient cells that DNA damage activates a mitochondrial respiration-dependent form of cell death, called MPT-driven necrosis. Cells deficient for p53 have high basal respiration, which primes MPT-driven necrosis. Finally, using metabolite profiling, we identified mitochondrial activity-dependent metabolic vulnerabilities that can be targeted to potentiate the lethality of DNA damage specifically in p53-deficient cells. Our findings reveal how the dual functions of p53 in regulating mitochondrial activity and the DNA damage response combine to facilitate the choice between apoptotic and non-apoptotic death.

Background Mania is a state of elated or irritable mood characterizing Bipolar Disorder type I (BD-I). Among the pharmacological treatments for the management of mania, mood stabilizers are regularly employed, with valproate being one of the most used because of its effectiveness. However, while the oral formulation is approved for acute mania, it is unclear whether the intravenous (IV) formulation could be a valid and safe alternative. Methods We performed a bibliographic research on PUBMED of all studies investigating the use of IV valproate as a treatment of acute mania in BD-I. A total of 13 studies met our inclusion criteria. Results Overall, the results suggest that IV valproate as a loading therapy is an efficacious, safe and well tolerated treatment for manic episodes, and it is comparable to the oral loading regimen. Interestingly, only a few patients experienced significant side effects due to the administration of the IV valproate. Limitations Few open label clinical trials have explored the effect of IV valproate in manic patients. Moreover, the original studies employed different clinical assessments and included manic patients taking other drugs, which made it impossible to determine whether the resolution of symptoms was due to valproate therapy alone. Additionally, serum valproate levels were not assessed by all studies. Conclusions IV valproate may represent a valid option for the management of acute mania, with comparable effects in terms of efficacy and safety to the oral valproate. However, larger and more homogeneous studies are warranted in order to collect more precise information on the beneficial effect of IV valproate.

In this work, one examines the prospects of using the surface plasmon resonance (SPR) effect in the Otto configuration for pressure and deformation sensing. An open Otto chip device was employed, and the chip was characterized by the use of an automated reflectometer operating at a wavelength of λ=975.1 nm. The active area of the device was characterized by reflectometry-based profilometry. Significant modulation of the SPR effect due to a variable gas pressure was observed at a fixed point on the device’s active area. A gap reduction to approximately 50% of its nominal value was observed when the gas pressure changed from 1.7 to 0.28 bar. In addition, profilometry characterization in conjunction with a rigorous regression analysis allowed determining, unambiguously, the gap profile of the device under fixed stress. The results indicate that the technique is feasible for either pressure or tactile sensing applications.

La gestión del riesgo de desastres (GRD) ha comenzado a tratarse en las agendas gubernamentales como un proceso que conduce al planeamiento y aplicación de políticas, estrategias, instrumentos y medidas que debe ser asumido por todos los sectores de la sociedad. Este enfoque supone un desafío para los gobiernos, quienes se ven interpelados por la necesidad de dar respuestas a situaciones de crisis generadas por fenómenos naturales o antrópicos, a través de la participación social y el trabajo colaborativo. En estas agendas se aborda especialmente la necesidad de que los gobiernos locales se transformen en actores clave para generar soluciones. El artículo tiene por objetivo analizar la incorporación de normas, reglas y discursos internacionales sobre la GRD en las políticas y prácticas de los gobiernos locales de la provincia de Córdoba (Argentina). Para ello se diseñó una matriz colaborativamente entre el ámbito académico y funcionarios de gobiernos locales. La hipótesis es que los gobiernos locales incorporan cambios a nivel discursivo y en componentes organizacionales más rápidamente que en la implementación de proyectos específicos. Además, se adoptan primero en procesos de toma de decisiones centralizados en los gobiernos locales, para luego incorporar procesos participativos que conduzcan a un enfoque de gobernanza.

Pesticide use generates wastewaters from its handling and from washing of spraying equipment, bringing concern about punctual discharge. Biobeds are biopurification systems for pesticide residues disposal, representing safe alternatives to avoid soil contamination. Peat that composes the original biomixture is not available all around Brazil. The aim of this work was to evaluate the efficiency of two alternative, accessible biomixtures, replacing peat, for treating phosmet (organophosphate insecticide) residues in biobeds and reducing its ecotoxicological effects. We hypothesized that the new biomixtures with pine litter (PB) or vermicompost (VB) could show the same degradation and detoxification efficiency as the standard biobed’s biomixture (SB) using peat. Small size bioreactors received 35 mg kg−1 of phosmet (Imidan®) in a laboratory-scale experiment. The pesticide degradation was monitored by chemical analysis. The decrease of ecotoxicity was determined by reproduction tests with collembolans (Folsomia candida) and enchytraeids (Enchytraeus crypticus), following ISO guidelines. Degradation curves showed that all biomixtures reached almost complete degradation of phosmet after 90 days. Collembolans were more sensitive than enchytraeid, confirming their usefulness in biomonitoring insecticide degradation. This work showed that both pine litter and vermicompost are potentially substitutes for peat in alternative biomixtures, since they were efficient in degrading the pesticide and reducing its ecotoxicity. Our results contribute for the development of newly, accessible biobeds for south Brazil, bringing the first study reports involving such biobeds capacity to degrade phosmet, which is a commonly used pesticide in this region.

Background Intratumor heterogeneity (ITH) is described as the presence of various clones within one tumor, each with their own unique features in terms of morphology, inflammation, genetics or transcriptomics. Heterogeneity provides the fuel for drug resistance; therefore, an accurate assessment of tumor heterogeneity is essential for the development of effective therapies. The purpose of this study was to dissect morphologic and molecular ITH in colorectal adenocarcinoma. Materials and methods A series of 120 V600EBRAF-mutated (V600EBRAFmt) consecutive metastatic colorectal adenocarcinomas was assessed for morphologic heterogeneity. The two heterogeneous components of each specimen underwent a histopathological, immunohistochemical and molecular characterization to evaluate: histologic variant, grading, tumor-infiltrating lymphocytes (TILs), mismatch repair proteins' expression, KRAS/BRAF/NRAS mutations, microsatellite instability (MSI) status and consensus molecular subtype (CMS). Results Thirty-one out of 120 (25.8%) V600EBRAFmt primary colorectal adenocarcinomas presented a heterogeneous morphology. Among these, eight cases had adequate material for molecular profiling. Five out of the eight (62.5%) cases resulted instable at MSI testing. The majority (62.5%) of the samples showed a CMS4 phenotype based on gene expression profiling. Heterogeneity in CMS classification was observed in four out of eight cases. One out of eight cases presented significant heterogeneity in the number of TILs between the two components of the tumor. Conclusions Although the distribution of the immune infiltrate appears relatively conserved among heterogeneous areas of the same tumor, changes in gene expression profile and CMS occur in 50% of V600EBRAFmt adenocarcinoma cases in our small series and might contribute to variability in response to anticancer therapy and clinical outcomes. Assessment of morphological and molecular ITH is needed to improve colorectal cancer classification and to tailor anticancer treatments and should be included in the pathology report., Highlights • Morphologic ITH is linked to transcriptomic heterogeneity in 50% of BRAFmt colorectal cancers. • Morphologic ITH might contribute to variability in response to anticancer therapy and clinical outcomes. • Assessment of morphological and molecular ITH may improve colorectal cancer classification and tailor treatments.

The ongoing Corona Virus Disease 2019 (COVID-19) pandemic appears to increase risk for mental illness, either directly due to inflammation caused by the virus or indirectly due to related psychosocial stress, resulting in the development of both anxious-depressive and psychotic symptoms. The purpose of the present study was to assess the frequency and characteristics of all patients with First Episodes Psychosis (FEP) without COVID-19 infection hospitalized in the first four months since lockdown in Milan. We recruited sixty-two patients hospitalized between March 8 to July 8, 2020 versus those first hospitalized in the same period in 2019. The two subgroups were compared for sociodemographic variables and clinical characteristics of the episodes. Patients with FEP in 2020 were significantly older than patients with FEP in 2021, and presented with significantly less substances abuse. Interestingly, patients presenting with FEP in 2020 were significantly older than patients with FEP in 2019. These data are compatible with the greater vulnerability to stressful factors during the pandemic, as well as with the greater concern regarding a possible COVID-19 infection producing brain damage causing the FEP.

Galactosemia is a rare genetic condition caused by mutation of enzymes involved in galactose and glucose metabolism. The varying clinical spectrum reflects the genetic complexity of this entity manifesting as acute neonatal toxicity syndrome, requiring prompt diagnosis and treatment, to more insidious clinical scenarios as observed in the subacute and chronic presentations. The current literature predominantly focuses on the long-standing sequelae of this disease. The purpose of this multicenter clinical report comprising 17 patients with galactosemia is to highlight the MR imaging patterns encompassing the whole spectrum of galactosemia, emphasizing the 3 main clinical subtypes: 1) acute neonatal presentation, with predominant white matter edema; 2) subacute clinical onset with a new finding called the "double cap sign"; and 3) a chronic phase of the disease with heterogeneous imaging findings. The knowledge of these different patterns together with MR spectroscopy and the clinical presentation may help in prioritizing galactosemia over other neonatal metabolic diseases and prevent possible complications.

Neuroendocrine tumours; Pancreatic cancer; Stomach cancer Tumores neuroendocrinos; Cáncer de páncreas; Cáncer de estómago Tumors neuroendocrins; Càncer de pàncrees; Càncer d'estómac There has been no major change of practice in gastrointestinal oncology at the European Society for Medical Oncology (ESMO) symposium 2021, but confirmation that immunotherapy in combination with chemotherapy has become standard of care in several indications. The European Organisation for Research and Treatment of Cancer (EORTC) Gastrointestinal Track Cancer Group has selected important phase II and III trials presented during the symposium across all gastrointestinal cancers as well as early reports on new drugs or new combinations that may change practice in the future. This work was supported by a donation from the Swiss Cancer Research Foundation from Switzerland. MC was supported by a grant by EORTC Cancer Research Fund (ECRF) and the Gastrointestinal Tract Cancer Group.

SUMMARY When evaluating anti-cancer drugs, two different measurements are used: relative viability, which scores an amalgam of proliferative arrest and cell death, and fractional viability, which specifically scores the degree of cell killing. We quantify relationships between drug-induced growth inhibition and cell death by counting live and dead cells using quantitative microscopy. We find that most drugs affect both proliferation and death, but in different proportions and with different relative timing. This causes a non-uniform relationship between relative and fractional response measurements. To unify these measurements, we created a data visualization and analysis platform called drug GRADE, which characterizes the degree to which death contributes to an observed drug response. GRADE captures drug- and genotype-specific responses, which are not captured using traditional pharmacometrics. This study highlights the idiosyncratic nature of drug-induced proliferative arrest and cell death. Furthermore, we provide a metric for quantitatively evaluating the relationship between these behaviors., In Brief Anti-cancer drugs affect both the growth and survival of cancer cells. Commonly used measures of drug sensitivity do not distinguish between these two different outcomes. Schwartz et al. developed GRADE, a drug analysis method that reveals the proportional contributions of cell death versus growth inhibition for an observed drug response., Graphical Abstract

The mineralization of the Lavras do Sul Mining District and Seival Mine are controlled by brittle structures associated with the emplacement of the volcanogenic rocks and granitoids located in Lavras do Sul region, southernmost Brazil. This magmatism is associated with the evolution of the Camaqua Basin, an Ediacaran basin generated during the post–collisional stage of development of the Dom Feliciano Belt. The regional tectonic process has led to the activation of a large–scale high–angle shear zones and intense fracturing in the brittle to brittle–ductile regime. The relative chronology of structures and stress–field variations were recognized through remote sensing and structural data. The ore–deposits are controlled by extensional fractures and normal fault systems with a N70°W/70–85°NE direction in Lavras do Sul and a N40–60°E/70–88°NW direction in Seival and are disseminated or occur associated with quartz and calcite veins, respectively. We made a comparison of structures going from regional scale to smaller mineralized areas. The structural analysis of remote sensing and geophysical images (aeromagnetometry and aerogamma–spectrometry) integrated with structural data allowed us to reconstruct the paleostress tensor that generated the main fault systems and associated fractures of the host rock, which enabled the hydrothermal fluid circulation and the ore deposition. The integration of structural data such as fault slip planes, slickenlines, shear fractures systems, extensional fractures and kinematic indicators with the stratigraphic data allowed us to reconstruct the main directions of the tectonic efforts associated with the emplacement of the mineralizing magmas. The mineralization is associated with the sinistral N70°W/80–88°NE oriented Palma–Jacques Fault in the Lavras do Sul Mining District as well as the sinistral N50°E/80–88°SE oriented Cabritos–Perau Fault and the sinistral N20°E/80–88°SW oriented Segredo Fault in Seival Mine region. Their maximum compressional stresses are subhorizontal and NW–SE oriented, while a late subhorizontal and NE–SW oriented compressional stress affected only the rocks of the Seival Mine. These two main compressive stresses are associated with the development of a transcurrent (escape) tectonics during the final evolution of the Dom Feliciano Belt, constrained by U Pb zircon geochronology between 600 and 580 Ma. Transcurrent and normal NE–SW oriented faults are more expressive in volcanogenic rocks of the Seival Mine area, while extensional vein–type NW–SE oriented fractures are the most important structures in the Lavras do Sul area. We suggested that N70°W/70–88°NE oriented monzonitic dikes in Lavras do Sul and N50°E/70–88°NW oriented andesitic to trachyandesitic dikes in Seival area are probably the source of the mineralization.

A numerical modeling analysis of a pulse train diffusion, representing an odorant injection in a natural gas pipeline, was carried out and compared with experimental data from a real pipeline. The main purpose of this study is to evaluate how the odorant dispersion occurs along the pipe. Due to technical limitations, the odorant is injected in the line as a pulse and it is important to find out the point in the pipeline where the oscillating concentration of odorant fits into a range of values that meet both the legislation and the interests of customers who may have the quality of their products affected by this oscillation. Since the natural gas pipelines do not have strong streamline curvatures and the flow is always turbulent, it is relatively easy to determine the velocity and concentration fields using the Computational Fluid Dynamics techniques. In this study the RANS (Reynolds Average Navier-Stokes) equations with the k − e turbulence model was used to build the mathematical model. Comparisons of the experimental data and numerical results show a strong agreement for the studied cases. Based on the results, it was possible to know the minimum and maximum values of odorant concentration along the pipelines.

Summary Localized radiotherapy (RT) induces an immunogenic antitumor response that is in part counterbalanced by activation of immune evasive and tissue remodeling processes, e.g., via upregulation of programmed cell death-ligand 1 (PD-L1) and transforming growth factor β (TGF-β). We report that a bifunctional fusion protein that simultaneously inhibits TGF-β and PD-L1, bintrafusp alfa (BA), effectively synergizes with radiotherapy, leading to superior survival in multiple therapy-resistant murine tumor models with poor immune infiltration. The BA + RT (BART) combination increases tumor-infiltrating leukocytes, reprograms the tumor microenvironment, and attenuates RT-induced fibrosis, leading to reconstitution of tumor immunity and regression of spontaneous lung metastases. Consistently, the beneficial effects of BART are in part reversed by depletion of cytotoxic CD8+ T cells. Intriguingly, targeting of the TGF-β trap to PD-L1+ endothelium and the M2/lipofibroblast-like cell compartment by BA attenuated late-stage RT-induced lung fibrosis. Together, the results suggest that the BART combination has the potential to eradicate therapy-resistant tumors while sparing normal tissue, further supporting its clinical translation.

An 8-step preparation of 14 C-labelled CHF6001, a potent phosphodiesterase 4 inhibitor in the treatment of respiratory diseases, is described. An overall yield of approximately 9% was obtained starting from copper[14 C]cyanide. The synthesis of a stable labelled version of CHF6001 is also reported using the commercially available trideuterated bromomethylcyclopropane as starting material.

Background: The hygiene hypothesis proposes that reduced exposure to infectious agents in early life would explain the increase of allergic and autoimmune diseases observed over the past decades in high-income countries. Methods: We conducted a matched case-control study on incident atopic dermatitis (AD). Cases were 426 outpatient children with a first diagnosis ofincident AD. Controls were 426 children attending a pediatric/dermatological visit for nonatopic disorders matched to cases (1:1). Particular attention was paid to the time elapsed between the markers of microbial exposure and disease onset, and we considered for controls the same time window of exposures from birth as his/her matched case. Odds ratios (ORs) were computed using multivariable conditional logistic regression models, according to center, sex, age, and period of enrollment, and including as potential confounders a family history of any allergy in parents, type of delivery, having siblings, keeping pets, age at weaning, and having had ≥4 infections. Results: The OR of AD first occurrence was 0.35 (P-value=.039) for children who had experienced ≥4 infections compared with those with no infections. A decreasing trend in risk was observed with increasing number of siblings (P-value=.023), the protective effect reaching about 40% for children with 2 or more siblings (OR=0.62; P-value=.048). Pet keeping, in particular daily contact with dogs, was inversely associated with AD risk (OR=0.40; P-value=.004). Conclusions: These results support the hygiene hypothesis in its broad sense. Early-life environmental exposures, including pathogens and commensals, act as “microbes contact carriers” influencing immune system balance early in life.

Purpose: The first aim of this study was to investigate the probiotic potential of Bifidobacterium breve BC104, isolated from a vaginal swab1, by assessing its antimicrobial activity against bacteria and fungi responsible for urogenital diseases (Candida spp., C. trachomatis, E. coli, E. faecalis, E. faecium, S. faecium, E. hirae, S. aureus and P. mirabilis) and against gastrointestinal pathogens (E. coli enterotoxigentic, S. typhimurium and Y. enterocolitica). To provide functional benefits to the gut and urogenital tract, oral probiotics must survive passage through the acidic stomach and colonize colon. Thus, tolerance to bile salts and low pH, as well as adhesion to Caco-2 and HeLa cells, were investigated. The second aim was to develop an oral gastro-resistant and mucoadhesive formulation able to favour bacterial survival during storage and following administration and bacterial intestinal and vaginal colonization. Methods: Antifungal activity was tested against Candida spp. by broth micro-dilution method. The anti-Chlamydia activity was measured as reduction in Chlamydia infectivity to HeLa cells treated with BC104. The antibacterial activity against the other pathogens was tested by using agar spot test2. The capability of Bifidobacterium to adhere to Caco-2 and HeLa cells was assessed by microscopy after Giemsa staining. To mimic gastric and intestinal conditions, Bifidobacterium cells were suspended in simulated gastric juice (pH 2) for three hours and then in simulated intestinal fluid (pH 7) for other three hours. Aliquots were taken every hours to estimate viability over time3. The oral formulation was obtained by spray-drying followed by prilling. Firstly, the overnight culture of BC104 was suspended in prebiotic media, containing an encapsulating agent (reconstituted skim milk 10%) and prebiotic (inulin 5%, oligofructose 5% and ascorbic acid 2.5%)4. Spray-drying process was performed at constant inlet temperature of 120°C. Secondly, gastro-resistant mucoadhesive beads were obtained by dripping and cooling of molten lauric acid (75%, p/p) containing CMC (10%, p/p) and spray-dried microcapsules (15%, p/p). Viability after the manufacturing procedure was evaluated as well as BC104 release from the beads. Results: B. breve BC104 exhibited a strong fungistatic activity against C. albicans and was able to reduce Chlamydia infectivity to HeLa cells. Moreover, BC104 exerted a good antibacterial activity towards all other pathogens examined, in particular against Escherichia coli, Staphylococcus aureus and Yersinia enterocolitica. BC104 showed a good ability to adhere to Caco-2 but not to HeLa cells, accordingly to the fact that bifidobacteria are a minor component of vaginal ecosystem, while they are essential in maintaining gastrointestinal homeostasis. Even after three hours at pH 2 and further exposure to the shift of pH under intestinal condition, BC104 maintained elevated cell concentration (> 105 CFU/mL), showing an intrinsic ability to resist to gastric acidity. Microcapsules containing B. breve showed high survival after spray drying (1010 CFU/g) and after 4 weeks of storage at 4°C. BC104 maintained also a good viability after incorporation inside beads (1.7*107 CFU/g). Conclusions: The results show that B. breve BC104 possess a good antimicrobial activity and can be deliver in oral gastro-resistant formulation. 1 Parolin, C., Marangoni, A., Laghi, L., Foschi, C., Ñahui Palomino, R.A., Calonghi, N., Cevenini, R., Vitali, B. Isolation of Vaginal Lactobacilli and Characterization of Anti-Candida Activity. PLoS One 2015, 10(6), e0131220. 2 Schillinge,r U., Lücke, F.K. Antibacterial activity of Lactobacillus sake isolated from meat. Appl Environ Microbiol 1989, 55(8), 1901-6. 3 Fernández, M.F., Boris, S., Barbés, C. Probiotic properties of human lactobacilli strains to be used in the gastrointestinal tract. J Appl Microbiol 2003, 94(3), 449-55. 4 Fritzen-Freire, C.B., Prudencio, E.S., Amboni, R.D.M.C., Pinto, S.S., Negrao-Murakami, A.N., Murakami, F. S. Microencapsulation of bifidobacteria by spray drying in the presence of prebiotics. Food Research Internationa 2011, 45, 306-312.

Zooplankton abundance and species composition provide information on environmental variability in the ocean. While zooplankton time series span the west coast of North America, less data exist off north-central California. Here, we investigated a zooplankton time series, focusing specifically on copepods, collected within the Gulf of the Farallones–Cordell Bank area (37.5° to 38.5°N) from 2004 to 2009. Impacted by seasonally strong, persistent upwelling, this study area is located downstream of a major upwelling center (Point Arena). We found copepod abundance and species composition differed significantly, particularly between the first three years (2004–2006) and the latter three years (2007–2009) of the study. These changes were mainly observed as changes in abundance of boreal copepod species, Pseudocalanus mimus and Acartia longiremis. These taxa showed increasing abundances for the latter three years of the study (2007–2009). During the first three years of the time series, environmental measurements in the region showed lower alongshore wind stress, weaker upwelling, minimal surface alongshore flow, and warmer surface ocean temperatures. Temporal variations in copepod abundance and species composition correlated with several of these environmental measurements (e.g., surface cross-shore and alongshore flows, upwelling, and alongshore wind stress), indicating environmental forcing of primary consumers and ecosystem productivity in this strong, persistent upwelling zone.

The aim of this study was to evaluate the cytotoxic effects of 2. 5% sodium hypochlorite (NaOCl), 17% ethylenediamine tetraacetic acid (EDTA), and 1% peracetic acid (PAA) on human fibroblasts. FG11 and FG15 cell lines were cultured in 24-well cell culture plates for cell proliferation assessment and 96-well cell culture plates for the methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay; Dulbecco's modified Eagle's medium (DMEM) was used as control data. The experimental solutions were used at 0. 01%, 0. 05%, and 0. 1% dilutions and assessed at 1-, 2-, and 4-hour intervals. Data were subjected to statistical analysis by two-way analysis of variance (ANOVA), followed by the Bonferroni test at a significance level of p0. 05. The assessment of cell proliferation in this study showed cytotoxicity to the fibroblasts with 2. 5% NaOCl for all three dilutions at all time intervals, 17% EDTA for the 0. 05% and 0. 1% dilutions at the 2- and 4-hour intervals, and 1% PAA for all three dilutions at the 4-hour interval. The cell viability assay (MTT assay) for fibroblasts showed 2. 5% NaOCl to be cytotoxic at the 0. 05% and 0. 1% dilutions at all time intervals, 17% EDTA to be cytotoxic at the 0. 1% dilution at the 2- and 4-hour intervals, and 1% PAA to be cytotoxic at the 0. 1% dilution at the 2- and 4-hour intervals. In conclusion, 1% PAA was less cytotoxic than 2. 5% NaOCl and 17% EDTA.O objetivo do presente estudo foi o de avaliar os efeitos citotóxicos de hipoclorito de sódio (NaOCl) a 2,5%, ácido etilenodiaminotetracético (EDTA) a 17% e ácido peracético (PAA) a 1% em fibroblastos humanos. As linhagens celulares FG11 e FG15 foram colonizadas em 24-well cell plates para avaliaçâo da proliferaçâo celularr e em 96-well cell plates para o ensaio de MTT; O médio modificado Dulbecco's Eagle's (DMEM) foi usado como controle. As soluções experimentais foram usadas com diluições de 0,01%, 0. 05%, e 0,1% e avaliadas com 1, 2 e 4 horas de intervalo. Os dados foram submetidos à análise estatística pelo two-way ANOVA, seguido do teste de Bonferroni com nivel de significância dep0. 05. A avaliaçâo da proliferação celular neste estudo mostrou o NaOCL a 2,5% como citotóxico nas 3 diluições e 3 intervalos de tempo, o EDTA a 17% nas diluições de 0,05% e 0,1% nos intervalos de 2 e 4 horas, e o PAA a 1% em todas as diluições no intervalo de 4 horas. O teste de viabilidade cellular (MTT) mostrou o NaOCl a 2,5% citotóxico a 0,05% e 0,1% em todos os intervalos, o EDTA a 17% citotóxico nas diluições de 0,1% nos intervalos de 2 e 4 horas e o PAA a 1% citotóxico na diluição de 0,1% nos intervalos de 2 e 4 horas. Como conclusão o PAA a 1% mostrou-se menos citotóxico que o NaOCl a 2,5%e o EDTA a 17%.