Developmental toxicity of bisphenol A diglycidyl ether (epoxide resin badge) during the early life cycle of a native amphibian species

Bisphenol A diglycidyl ether (BADGE) is used in packaging materials, in epoxy adhesives, and as an additive for plastics, but it is also a potential industrial wastewater contaminant. The aim of the present study was to evaluate the adverse effects of BADGE on Rhinella arenarum by means of standardized bioassays at embryo–larval development. The results showed that BADGE was more toxic to embryos than to larvae at all exposure times. At acute exposure, lethality rates of embryos exposed to concentrations of 0.0005 mg/L BADGE and greater were significantly higher than rates in the vehicle control, whereas lethality rates of larvae were significantly higher in concentrations of 10 mg/L BADGE and greater. The toxicity then increased significantly, with 96‐h median lethal concentrations (LC50s) of 0.13 mg/L and 6.9 mg/L BADGE for embryos and larvae, respectively. By the end of the chronic period, the 336‐h LC50s were 0.04 mg/L and 2.2 mg/L BADGE for embryos and larvae, respectively. This differential sensitivity was also ascertained by the 24‐h pulse exposure experiments, in which embryos showed a stage‐dependent toxicity, with blastula being the most sensitive stage and S.23 the most resistant. The most important sublethal effects in embryos were cell dissociation and delayed development, whereas the main abnormalities observed in larvae related to neurotoxicity, as scare response to stimuli and narcotic effect.Fil: Hutler Wolkowicz, Ianina Ruth. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Svartz, Gabriela Veronica. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Aronzon, Carolina Mariel. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Perez Coll, Cristina Silvia. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Paleoecotoxicology: the impact of chemical and physical stress in the evolutionary process.

Present-day biodiversity, estimated to comprise more than 100 millionspecies, has developed in around 4,000 million years on the basisof the ability of life forms to adapt and multiply at a rate that surpassedextinctions. Species, including humans, depend on the ecosystemsthat have operated with no or minimal human intervention upto recent years. Recent extinction rates are 100–1,000 times their prehumanlevels in taxonomically diverse groups from widely differentenvironments. Moreover, it is accepted that if all species currentlyendangered become extinct, then future extinction rates will be 10times recent rates (1). Although chemicals are the basic units for thedevelopment of life, it seems meaningful to take into accountParacelsus’ statement that “all things are poison and nothing is withoutpoison.” From this perspective it seems obvious that chemical andphysical features have been considered driving forces of evolutionaryprocesses from the beginning of recorded history. Estimates suggestthat the current world production of chemicals is 400 million metrictons. Almost 11 million naturally occurring or man-made chemicalshave been identified in the CAS Registry File, although only a smallportion of them is commercially available. I would like to present thehypothesis of a direct link between chemical stress and a major massextinction process, the Cretaceous-Tertiary (C-T) event, with the aimof providing a more holistic view on the potential of chemical stresson the evolutionary process.Fil: Herkovits, Jorge. Fundación Pro Salud y Medio Ambiente. Instituto de Ciencias Ambientales y Salud; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Evoecotoxicology: Environmental Changes and Life Features Development during the Evolutionary Process—the Record of the Past at Developmental Stages of Living Organisms

For most of evolutionary history, scientific understanding of the environment and life forms is extremely limited. In this commentary I discuss the hypothesis that ontogenetic features of living organisms can be considered biomarkers of coevolution between organisms and physicochemical agents during Earth’s history. I provide a new vision of evolution based on correlations between metabolic features and stage-dependent susceptibility of organisms to physicochemical agents with well-known environmental signatures. Thus, developmental features potentially reflect environmental changes during evolution. From this perspective, early multicellular life forms would have flourished in the anoxic Earth more than 2 billion years ago, which is at least 1.2 billion years in advance of available fossil evidence. The remarkable transition to aerobic metabolism in gastrula-stage embryos potentially reflects evolution toward tridermic organisms by 2 billion years ago. Noteworthy changes in embryonic resistance to physicochemical agents at different developmental stages that can be observed in living organisms potentially reflect the influence of environmental stress conditions during different periods of evolutionary history. Evoecotoxicology, as a multidisciplinary and transdisciplinary approach, can enhance our understanding of evolution, including the phylogenetic significance of differences in susceptibility/resistance to physicochemical agents in different organisms

Melanin Adhesivity for Possible Trapping of SARS-CoV-2 on Chin Straps: A Proof-of-concept Assay Using Model Nanoparticles

In the frame of COVID-19 pandemic, improved chin straps are obviously necessary to better prevent aerial infection by SARS-CoV-2. Adhesivity of melanins could be applied for trapping virus, but due to present limitations to work with infective agents, we have performed a proof-on-concept assay using zinc oxide (ZnO) nanoparticles with similar size (about 100 nm) as a virus model. Cotton fabrics were impregnated with allomelanin isolated from black beans, and ZnO solutions filtered through melanin-containing filters. Results and controls showed that these filters retained efficiently the nanoparticles, suggesting that melanin-treated chin straps could be a valuable and effective protection resource to trap virus and avoid infection. .Fil: Stockert, Juan Carlos. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; ArgentinaFil: Herkovits, Jorge. Fundación Pro Salud y Medio Ambiente; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Photodynamic toxicity and its prevention by antioxidative agents in Bufo arenarum embryos

In this work we describe an experimental model to evaluate the photodynamic toxicity on amphibian embryos, as well as the protective effect of antioxidants against the lethal oxidative stress induced by photosensitization. Bufo arenarum embryos were treated with 10 mg/l methylene blue (MB) in AMPHITOX solution for 72 h and then irradiated with a red laser or white light for variable times. Both light sources affected the survival of MB-treated animals and lethal effects occurred within the initial 12 h post-irradiation. For white light irradiation, the most effective phototoxic condition in our study, the LD10, 50 and 90 at 6 h post-irradiation corresponded to 13.57, 19.87 and 29.10 J/cm2, respectively. To explore the action of antioxidants against the photogenerated oxidative stress, MB-treated embryos were incubated with 1 mM glutathione (GSH) or ascorbic acid (AA) during 48 h before irradiation. For GSH and 21.6 J/cm2 irradiation, the survival increased from 20 to 90%, whereas 100% survival was achieved with AA even after 43.2 J/cm2 irradiation. These results indicate that both the lethal photodynamic effect and its prevention by antioxidants can be evaluated by means of a simple toxicity test employing amphibian embryos.Fil: Stockert, Juan C.. Fundación Pro Salud y Medio Ambiente. Instituto de Ciencias Ambientales y Salud; ArgentinaFil: Herkovits, Jorge. Fundación Pro Salud y Medio Ambiente. Instituto de Ciencias Ambientales y Salud; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Hypersaline antiseptic therapy to prevent progression of COVID-19: a proposal

SARS-CoV-2 placed us in the urgent challenge of reducing morbidity, mortality, and the effective reproduction number (R), all highly worrying aspects of the COVID-19 pandemic. Bearing in mind that the treatments tested, at best, only achieved a partial effect, there is no vaccine against the disease available for everybody, and the eventual outbreak of virus variants could result in enhanced morbidity, there have been concerns raised as to the global impact of the pandemic, which makes reasonable to expand prevention measures. External protections, including antiseptic measures, are highly recommended. Considering early signs of infection—including sore throat, taste loss, dry mouth, and mucosal lesions such as ulcerations, enanthema, and macules are habitual symptoms of the disease, indicative that the virus makes an early season in these locations, it is logical to explore the possibility of using a local spray antiseptic compatible with COVID-19 at the beginning of the signs and symptoms.El SARS-CoV-2 plantea el desafío de reducir la morbilidad, mortalidad y el número de reproducción (R). Dado que los tratamientos son solo parcialmente efectivos, la vacuna no está disponible para todos y las variantes del virus pueden aumentar la morbilidad, se recomiendan medidas de prevención adicionales. Dado que los primeros síntomas de COVID-19 incluyen dolor de garganta, pérdida de gusto y boca seca, es lógico considerar el uso de antisépticos en aerosol en la cavidad oral, donde se ha comprobado que el virus infecta las células. La saliva, altamente infecciosa, juega un papel en la transmisión, justificando el uso de tratamientos antisépticos orofaríngeos desde los primeros síntomas. Estudios in vitro indican que soluciones hipersalinas de NaCl pueden inactivar el virus y fortalecer la respuesta inmune. Aunque los ensayos clínicos han demostrado que el NaCl puede acortar la duración de enfermedades virales, se requieren más estudios controlados para confirmar su eficacia contra el SARS-CoV-2. Una solución hipersalina es de bajo costo y fácil preparación, siendo una opción potencial en la prevención de la COVID-19, especialmente en personas de alto riesgo.Fil: Herkovits, Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación Pro Salud y Medio Ambiente; ArgentinaFil: Stockert Cossu, Juan Carlos. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; Argentin

Las fronteras de la medicalización: tensiones en torno a la identificación y valoración de la desnutrición infantil en un centro de atención primaria de la ciudad de Buenos Aires

La medicalización de la vida y sus implicancias en cuanto a la producción de subjetividades han sido fenómenos destacados por las ciencias humanas en el estudio de la salud y la enfermedad. Sin embargo, el análisis de sus expresiones locales permanece insuficientemente tratado. El presente trabajo tiene como propósito avanzar en esta dirección mediante el estudio etnográfico del proceso de medicalización de la desnutrición infantil en un centro sanitario de la ciudad de Buenos Aires. Abordaremos las singularidades involucradas en la percepción valorativa del cuerpo y su contexto alimentario por parte de los profesionales de la salud y los destinatarios de sus acciones terapéuticas. Destacamos que los criterios de percepción y los valores morales que animan las posiciones sociales de los profesionales del sector salud y los destinatarios de sus acciones imposibilitaron la institucionalización de la visión médica. Concluimos que el proceso analizado subraya la necesidad de exceder los enfoques que abordan la medicalización exclusivamente desde el ángulo de la imposición. La historia social de los grupos involucrados y los modos de relacionamiento que establecen en escenarios locales constituyen elementos esenciales para comprender las singularidades de estos procesos.</jats:p

“Yo no quería matarlo”: Disputas y conflictos en la agresión letal en jóvenes de sectores populares

“I didn’t want to kill him”: Disputes and Conflicts in Lethal Aggression in Young People from Popular Sectors This paper aims to understand how everyday disputes in spaces of close sociability lead to homicides in young people. The central problems that guide our reflection are linked to the narrative explicitation of the symbolic, moral and emotional frameworks that compose them. The research was carried out in popular neighborhoods in the metropolitan area of the city of Buenos Aires. We argue that these homicides are inscribed in sociabilities that interweave expressions of “the intolerable” as an embodied experience. This experience drives a radical action in the space of interaction that can lead to lethal aggression.Este trabajo se propone comprender cómo disputas cotidianas en espacios de sociabilidad próxima conducen a homicidios en jóvenes. Los problemas centrales que guían nuestra reflexión están vinculados con la explicitación narrativa de los entramados simbólicos, morales y emocionales que los componen. La investigación se realizó en barrios populares del área metropolitana de la ciudad de Buenos Aires. Sostenemos que estos homicidios se inscriben en sociabilidades que entraman expresiones de “lo intolerable” como experiencia corporizada. Esta experiencia impulsa una acción radical en el espacio de interacción que puede conducir a la agresión letal.“Eu não queria matá-lo”: Disputas e conflitos na agressão letal entre jovens de setores populares Este artigo tem como objetivo compreender como as disputas cotidianas em espaços de sociabilidade próxima levam a homicídios de jovens. Os problemas centrais que orientam nossa reflexão estão ligados à explicitação narrativa dos quadros simbólicos, morais e emocionais que os compõem. A pesquisa foi realizada em bairros da classe trabalhadora na área metropolitana da cidade de Buenos Aires. Argumentamos que esses homicídios estão inscritos em sociabilidades que entrelaçam expressões do “intolerável” como uma experiência incorporada. Essa experiência impulsiona uma ação radical no espaço de interação que pode levar a uma agressão letal

Nickel tissue residue as a biomarker of sub-toxic exposure and susceptibility in amphibian embryos

Although low level exposure to physicochemical agents is the most common environmental scenario, their effects on living organisms are very controversial. However, there is an increasing need to integrate low level exposures from risk assessment to remediation purposes. This study focus on the possibility to employ Ni tissue residue values as biomarkers of sub-toxic exposure and susceptibility to this metal in a range of almost pristine to sub-toxic concentrations for Rhinella arenarum embryos. For that purpose, three batches of amphibian embryos were pretreated during 10 days with three increasing concentrations of Ni starting in 2, 8 and 20 ìg Ni2+ L-1 and ending in 16, 64 and 160 ìg Ni2+ L-1 (in natural fresh waters this value ranges from 2 to 10 ìg L-1; the LC50-24 hr for R. arenarum is 26.2 mg Ni2+ L-1). For the experimental conditions, the Ni tissue residue values at 360 hr post exposure were 0.5, 2.1 and 3.6 ìg Ni g-1 embryo w/w respectively, corresponding to BCFs of 31, 33 and 23. The susceptibility to Ni in those experimental embryos was evaluated by means of challenge exposures to three lethal concentrations of this metal (10, 20 and 30 mg Ni2+ L-1), registering survival during the following 10 days of treatment. As a general pattern, the lower, intermediate and higher pretreatments with Ni resulted in enhanced, neutral and adverse effects on embryonic survival respectively. Thus, sub-toxic exposure to Ni could modify the resistance of the amphibian embryo to this metal and Ni tissue residue values could be considered as biomarkers of both, exposure and susceptibility.Fil: Perez Coll, Cristina Silvia. Fundación Pro Salud y Medio Ambiente; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Instituto de Investigación en Ingeniería Ambiental; ArgentinaFil: Sztrum, Abelardo. Fundación Pro Salud y Medio Ambiente; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Herkovits, Jorge. Fundación Pro Salud y Medio Ambiente; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin