The role of reactive oxygen species (ROS) in the regulation of hair follicle (HF) cycle and skin homeostasis is poorly characterized. ROS have been traditionally linked to human disease and aging, ...but recent findings suggest that they can also have beneficial physiological functions in vivo in mammals. To test this hypothesis, we transiently switched on in situ ROS production in mouse skin. This process activated cell proliferation in the tissue and, interestingly, in the bulge region of the HF, a major reservoir of epidermal stem cells, promoting hair growth, as well as stimulating tissue repair after severe burn injury. We further show that these effects were associated with a transient Src kinase phosphorylation at Tyr416 and with a strong transcriptional activation of the prolactin family 2 subfamily c of growth factors. Our results point to potentially relevant modes of skin homeostasis regulation and demonstrate that a local and transient ROS production can regulate stem cell and tissue function in the whole organism.
Intracellular parasites can alter the cellular machinery of host cells to create a safe haven for their survival. In this regard, microsporidia are obligate intracellular fungal parasites with ...extremely reduced genomes and hence, they are strongly dependent on their host for energy and resources. To date, there are few studies into host cell manipulation by microsporidia, most of which have focused on morphological aspects. The microsporidia Nosema apis and Nosema ceranae are worldwide parasites of honey bees, infecting their ventricular epithelial cells. In this work, quantitative gene expression and histology were studied to investigate how these two parasites manipulate their host's cells at the molecular level. Both these microsporidia provoke infection-induced regulation of genes involved in apoptosis and the cell cycle. The up-regulation of buffy (which encodes a pro-survival protein) and BIRC5 (belonging to the Inhibitor Apoptosis protein family) was observed after infection, shedding light on the pathways that these pathogens use to inhibit host cell apoptosis. Curiously, different routes related to cell cycle were modified after infection by each microsporidia. In the case of N. apis, cyclin B1, dacapo and E2F2 were up-regulated, whereas only cyclin E was up-regulated by N. ceranae, in both cases promoting the G1/S phase transition. This is the first report describing molecular pathways related to parasite-host interactions that are probably intended to ensure the parasite's survival within the cell.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Summary
Nosema ceranae is a parasite of the epithelial ventricular cells of the honey bee that belongs to the microsporidian phylum, a biological group of single‐cell, spore‐forming obligate ...intracellular parasites found in all major animal lineages. The ability of host cells to accommodate a large parasitic burden for several days suggests that these parasites subvert the normal host cells to ensure optimal environmental conditions for growth and development. Once infected, cells can counteract the invasive pathogen by initiating their own death by apoptosis as a defence strategy. To determine whether N. ceranae blocks apoptosis in infected ventricular cells, cell death was assessed in sections of the ventriculum from experimentally infected honey bees using the TUNEL assay and by immunohistochemistry for caspase‐3. Ventricular epithelial cells from infected bees were larger than those in the uninfected control bees, and they contained N. ceranae at both mature and immature stages in the cytoplasm. Apoptotic nuclei were only observed in some restricted areas of the ventriculum, whereas apoptosis was typically observed throughout the epithelium in uninfected bees. Indeed, the apoptotic index was higher in uninfected versus infected ventriculi. Our results suggested that N. ceranae prevents apoptosis in epithelial cells of infected ventriculi, a mechanism possible designed to enhance parasite development.
Pollen substitute diets have become increasingly important for maintaining strong and healthy honey bee colonies. Palatability and nutritional value are key attributes of a good diet. Since beebread, ...which is pollen fermented by the bees, is the main food of the worker nurse bees that feed and care for the bee larvae, pollen substitutes should have similar attributes. In an attempt to simulate this natural food source, an inoculum prepared from beebread was used to ferment a pollen-substitute diet. Newly emerged bees were fed on the diets for seven days. They consumed significantly more fermented than unfermented diet. Hemolymph protein levels were significantly higher in bees that had been fed a fermented versus an unfermented diet, though still significantly lower than in bees fed on beebread. Vitellogenin (a key storage protein for honey bees) levels were also increased significantly in bees fed the fermented versus the non-fermented diet. Survival rates were higher for bees fed the fermented versus the non-fermented diet, though the difference was not significant. We conclude that fermentation by beebread-derived microorganisms can improve the acceptance and utility of an artificial protein diet for honey bees.
Summary
N
osema ceranae
is a parasite of the epithelial ventricular cells of the honey bee that belongs to the microsporidian phylum, a biological group of single‐cell, spore‐forming obligate ...intracellular parasites found in all major animal lineages. The ability of host cells to accommodate a large parasitic burden for several days suggests that these parasites subvert the normal host cells to ensure optimal environmental conditions for growth and development. Once infected, cells can counteract the invasive pathogen by initiating their own death by apoptosis as a defence strategy. To determine whether
N
. ceranae
blocks apoptosis in infected ventricular cells, cell death was assessed in sections of the ventriculum from experimentally infected honey bees using the
TUNEL
assay and by immunohistochemistry for caspase‐3. Ventricular epithelial cells from infected bees were larger than those in the uninfected control bees, and they contained
N
. ceranae
at both mature and immature stages in the cytoplasm. Apoptotic nuclei were only observed in some restricted areas of the ventriculum, whereas apoptosis was typically observed throughout the epithelium in uninfected bees. Indeed, the apoptotic index was higher in uninfected versus infected ventriculi. Our results suggested that
N
. ceranae
prevents apoptosis in epithelial cells of infected ventriculi, a mechanism possible designed to enhance parasite development.
Pharmaceutical discharges into the aquatic ecosystem are of environmental concern and sewage treatment plants (STPs) have been pointed out as the major source of these compounds to coastal zones, ...where oceanic disposal of sewage occurs through submarine outfalls. Diclofenac (DCF) is one of the most frequently detected pharmaceuticals in water, but little is known about the effects on marine organisms. In this study, we employed a tiered approach involving the determination of environmental concentrations of DCF in marine water and the adverse biological effects for fertilization, embryo-larval development and biomarker responses of the mussel Perna perna. Results indicate that effects in fertilization rate and embryo-larval development were found in the order of mg·L−1. However, low concentrations of DCF (ng·L−1) significantly decreased the lysosomal membrane stability and COX activity, as well as triggered DNA damage, oxidative stress and changes in antioxidant defenses. Our results point to an environmental hazard at coastal ecosystems and suggest the need for improvements in the treatment of domestic wastewater aiming to reduce DCF concentrations, as well as regulation on current environmental legislation and monitoring of aquatic ecosystems.
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•Toxicity to gametes and embryos exposed to Diclofenac.•Cyto-genotoxicity in adult mussels exposed to ng·L-1 levels.•Similar mode of action in a non-target organism.•Adverse effects at environmentally relevant concentrations.
As abelhas são consideradas os polinizadores mais importantes das culturas agrícolas ao redor do mundo e os mais efetivos. As necessidades nutricionais desses animais são atendidas através da coleta ...de néctar (transportado à colônia e armazenado nos favos) e pólen (consumido após a realização de processos fermentativos de microrganismos, denominando-se beebread ou pão de abelha). O beebread possui uma atratividade natural a essas abelhas. Com o desaparecimento das abelhas, pela falta de alimento disponível, entre outras causas, a alimentação suplementar auxilia apicultores na manutenção dessas colônias em períodos críticos, porém esses suplementos muitas vezes não possuem valor nutritivo adequado e fraca atratividade. Verificar assim quais os compostos voláteis presentes no beebread de diferentes regiões do Brasil e uma dieta fermentada a base desse pólen, faz-se hoje uma importante ferramenta para tentar elucidar o problema da atratividade. Foram feitas análises de atratividade, através de testes em túnel Y com duas dietas artificiais: uma dieta não fermentada e outra fermentada com o próprio beebread, durante quatro dias; análises cromatográficas, com beebread coletado de colônias de abelhas A. mellifera em: Ribeirão Preto/São Paulo; Mossoró/Rio Grande do Norte; Muzambinho/Minas Gerais; Porto Alegre/Rio Grande do Sul; análise polínica das amostras de beebread de todas as localidades. Os testes em túnel Y confirmaram que as abelhas são atraídas pelo cheiro da dieta fermentada, sendo que quanto mais tempo permanecem sem alimentação proteica, mais rapidamente é a escolha do local onde se encontra a dieta fermentada. Já as análises químicas apontaram que tanto a dieta fermentada quanto o beebread coletado nas diferentes localidades possuem alguns compostos voláteis em comum, oriundos principalmente de fermentação: Acetoína, Ácido Acético e 2,3-Butanodiol. Sendo que a classe química que esteve mais presente foi a de terpenoides. A análise polínica das amostras de beebread confirmou os dados obtidos pela análise química. Nossos dados indicam a grande importância da gama de compostos encontrados no beebread e a presença daqueles que indicam a fermentação. Assim, saber qual desses compostos voláteis são atrativos às abelhas será fundamental para a liofilização dos mesmos e adicioná-los às rações proteicas artificiais, tornando-as mais palatáveis e atrativas para esses insetos.
Honey bees are considered to be the most important and most effective pollinators of agricultural crops throughout the world. The nutritional necessities of these insects are met by collecting nectar (transported to the colony and stored in the comb) and pollen (consumed after it has been fermented by microorganisms, becoming bee bread). Bee bread contains substances that are attractive to the bees. As the increasing need for bees has become hard to meet because of a lack of natural food sources to sustain their colonies, it has become increasingly common for beekeepers to provide pollen substitutes. However, nutritional quality and palatability are often inferior to those of bee bread. In a search for key compounds that could help stimulate the bees to consume artificial diets, we examined the volatile compounds present in bee bread and in artificial protein diets that had been fermented with microorganisms present in bee bread. Attractiveness of fermented versus unfermented artificial protein diets for honey bees was compared using a Y odor choice test, for four days. Additionally, chromatographic analyses were made of bee bread collected from apiaries located in Ribeirão Preto, São Paulo, Mossoró, Rio Grande do Norte, Muzambinho, Minas Gerais, and Porto Alegre, Rio Grande do Sul. Pollen analyses were made of all bee bread samples to determine plant origin. The bees preferred the odors from fermented compared to unfermented diet. The rapidity with which they made this choice was positively correlated with the time that they remained without protein food. Several of the volatiles from bee bread from the different regions of the country were similar, despite considerably different contributing pollen species. These volatiles were also found in the fermented pollen substitute diet, indicating that they were products of fermentation; these included acetoin, ascetic acid and 2,3-butanediol. The most common class of volatiles in these materials was terpenoids. There was a large variety of volatile compounds in the bee bread samples and in the fermented bee diet; these included substances that are a result of fermentation. A next step would be to determine which of these substances are most attractive to bees that require protein, so that they can be added to artificial bee diets in order to make them more palatable and useful.
To describe the personal protective equipment training strategies during the beginning of the pandemic and to investigate the association between training and COVID-19 infection among healthcare ...workers.
This cross-sectional study conducted between March and May 2020 included 7,142 healthcare professionals who were eligible for both online and face-to-face simulation-based training on personal protective equipment use. Simulation training attendance was assessed by reviewing the attendance list, and the COVID-19 sick leave records recovered from the institutional RT-PCR database used to grant sick leave. The association between personal protective equipment training and COVID-19 was investigated using logistic regression, adjusted for sociodemographic and occupational characteristics.
The mean age was 36.9 years (± 8.3), and 72.6% of participants were female. A total of 5,502 (77.0%) professionals were trained: 3,012 (54.7%) through online training, 691 (12.6%) through face-to-face training, and 1,799 (32.7%) through both strategies. During the study period, 584 (8.2%) COVID-19 cases were diagnosed among these professionals. The number of positive RT-PCR tests was 180 (11.0%) for untrained professionals, 245 (8.1%) for those trained only online, 35 (5.1%) for those trained face-to-face, and 124 (6.9%) for those trained with both strategies (p<0.001). Participants who received face-to-face training had a 0.43 lower risk of contracting COVID-19.
Personal protective equipment training decreased the odds of COVID-19 among healthcare professionals, with face-to-face simulation-based training being most effective.
As informações acerca de plantas medicinais e sua utilização são pouco exploradas no contexto escolar. No entanto, os estudantes frequentemente chegam à escola com saberes e experiências sobre o uso ...de vegetais com fins terapêuticos, adquiridos no seio familiar. Explorar esse conhecimento de forma didática na escola permitirá resgatar conhecimentos que estão, muitas vezes, relacionados ao contexto sociocultural do aluno, promovendo, dessa maneira, uma aprendizagem satisfatória. Além disso, estimula-se o esclarecimento voltado à etnobotânica e a conscientização dos estudantes sobre a importância da preservação da diversidade biológica. O objetivo deste trabalho consistiu em analisar a percepção dos alunos do ensino fundamental sobre a utilização de plantas medicinais. A pesquisa foi realizada por meio de um questionário, caracterizando-se como um estudo qualitativo e descritivo. Participaram da pesquisa 73 estudantes de instituições públicas de Natal, RN. A maioria dos estudantes compreende que as plantas medicinais podem ser empregadas como alternativa no tratamento de enfermidades; 62 relataram já ter utilizado com finalidade terapêutica. Dentre os motivos associados ao uso das plantas medicinais, destacam-se: tratamento estético, infusões com finalidade degustativa e alívio de cefaleias. Observa-se que o conhecimento dos estudantes sobre plantas medicinais e suas propriedades ainda é insatisfatório, mesmo possuindo o conhecimento básico e relatando experiências de utilização. Isso denota que essa temática ainda é pouco explorada no ambiente escolar, e o conhecimento transmitido está predominantemente vinculado ao âmbito familiar, necessitando ser aprofundado no contexto educacional formal.
ABSTRACT
The information about medicinal plants and their use is rarely explored in the school context. However, students often come to school with knowledge and experiences about the use of plants for therapeutic purposes, acquired within their families. Exploring this knowledge in a didactic way will allow recovering knowledge that is often related to student's sociocultural context, thus promoting satisfactory learning. Additionally, it stimulates awareness focused on ethnobotany and students' understanding of the importance of preserving biological diversity. The objective of this study was to analyze the perception of elementary school students regarding the use of medicinal plants. The research was conducted through a questionnaire, characterized as a qualitative and descriptive study. 73 students from public institutions in Natal, RN, participated in the research. The majority of students understand that medicinal plants can be used as an alternative in treating illnesses; 62 reported having used them for therapeutic purposes. Among the reasons associated with the use of medicinal plants, we find: cosmetic treatment, infusions for tasting purposes, and headache relief. It is observed that the students' knowledge about medicinal plants and their properties is still unsatisfactory, despite having basic knowledge and reporting experiences of use. It indicates that this theme is still little explored in school environment, and transmitted knowledge is predominantly linked to family context. Therefore, it is necessary further development in the formal educational context.Keywords: Medicinal herbs, Treatment of illnesses, Reading the world, Ethnobotany, Basic education.
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