RESUMO
Multi-species tests in bioassays offer a holistic view of the ecosystem's response to toxicity, as different species display varying sensitivities to pollutants. This research aimed to assess the ability of toxicity tests' to distinguish contamination levels, examine site-specific effects, and investigate seasonal variability. Using a multispecies approach (Nannochloropsis oceanica, Artemia franciscana, and Arbacia nigra), bioassays evaluated marine water quality from Callao Bay in Peru across four sampling areas (Naval School: PA1, Peruvian Marine Institute: PA2, Callao Pier: PA3, and San Lorenzo Island: PA4). These species, with varying sizes and morphologies, are relevant to marine systems and ideal for multispecies toxicity testing, contributing to broader environmental impact discussions. To conduct toxicity bioassays, seasonal evaluations were performed in fall, winter, spring, and summer. Brine shrimp displayed seasonal variations in toxicity values, with notable mortality rates during winter. Nannochloropsis oceanica was the most sensitive species, showing moderate toxicity across seasons. Areas impacted by pollution sources, such as wastewater and maritime traffic, exhibited the highest toxicity levels (PA3 and PA4). These fluctuations underscore the need to consider seasonal and local conditions when assessing organism sensitivity to seawater contaminants. Additionally, they reveal the complex interplay between environmental factors, water quality, and organism responses in marine ecosystems.
Assuntos
Artemia , Baías , Água do Mar , Qualidade da Água , Animais , Artemia/efeitos dos fármacos , Peru , Estações do Ano , Monitoramento Ambiental/métodos , Ecossistema , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Bioensaio/métodosRESUMO
BACKGROUND: One bioassay for detecting acaricide resistance in livestock ticks is the adult immersion test (AIT), wherein engorged ticks are briefly immersed into a solution of a particular acaricidal compound and examined for mortality, their egg-laying capacity and offspring hatchability in vitro. Usually, the recommended label dose or an established discriminating dose of an acaricide is used to determine high mortality (≥ 95%) of susceptible tick strains. Such a test intends to detect the presence of resistance in a tick population. However, the adult immersion test does not directly translate the bioassay results to the predicted efficacy in the field. In this paper, we used the AIT as an initial screening bioassay supplemented with the resistance intensity test (RIT), a novel larval-based bioassay, wherein the resistance level can be determined and translated to the expected field efficacy. This was done by adopting World Health Organisation (WHO) guidelines for resistance detection in mosquitoes, which combines a 1 × recommended dose with 5 × and 10 × concentrated doses to reveal low, moderate and high resistance intensity, respectively. METHODS: Engorged Rhipicephalus microplus ticks were collected from cattle at six different ranches across Rio Grande do Sul, Brazil, as part of the state's acaricide resistance surveillance program. Groups of adult ticks from each field collection were subjected to the AIT from each field sample. Additionally, engorged female ticks from each ranch were allowed to lay eggs, and their larval progeny aged 14 to 28 days were then used in the RIT. Deltamethrin and a combination of cypermethrin, chlorpyrifos and piperonyl butoxide were used in both tests, and the results were statistically analysed. RESULTS: The in vitro efficacy of deltamethrin against adult ticks in the AIT ranged between 8.74% and 25.38%. The corresponding RIT results on their larval progeny indicated a high resistance level. In the immersion test, the in vitro efficacy of the combination of cypermethrin, chlorpyrifos, and piperonyl butoxide against adult ticks ranged between 49.31% and 100%. The corresponding RIT results on their larval progeny indicated a similar response ranging from fully susceptible to low or moderate resistance. The Pearson correlation coefficient (r = 0.883) showed a high correlation between tick mortality at the 1 × recommended concentrations of acaricides in both tests. CONCLUSIONS: The resistance intensity test is a valuable addition to the range of bioassays currently available for detecting acaricide resistance by determining the level of acaricide resistance. This is relevant to whether or not to continue using a particular acaricidal class for controlling cattle ticks.
Assuntos
Acaricidas , Bioensaio , Larva , Rhipicephalus , Infestações por Carrapato , Animais , Rhipicephalus/efeitos dos fármacos , Acaricidas/farmacologia , Bioensaio/métodos , Bovinos , Infestações por Carrapato/veterinária , Infestações por Carrapato/parasitologia , Larva/efeitos dos fármacos , Piretrinas/farmacologia , Feminino , Resistência a Medicamentos , Doenças dos Bovinos/parasitologia , Brasil , Clorpirifos/farmacologia , NitrilasRESUMO
The release in aquatic environments of emergent contaminants such as copper oxide nanoparticles (CuO-NPs) has generated concerns on their short- and long-term toxicity and the potential risk for more vulnerable animal groups, such as amphibians. In this sense, the aim of this work was to evaluate the toxicity of CuO-NPs in comparison with its respective salt (CuCl2) in embryos and larvae of a native amphibian, Rhinella arenarum, by acute (96 h) and chronic (504 h) standardized bioassays. Lethality and sublethal effects such as developmental, morphological, and ethological alterations were assessed in a wide range of concentrations (0.001-100 mg/L). Neurotoxic effects by acetyl (AChE) and butyrylcholinesterase (BChE) activity levels and changes in the lipid content were also assessed at sublethal concentrations. Results showed that CuCl2 caused higher lethality than CuO-NPs in both developmental periods. Embryos were more sensitive than larvae with LC50-96 h = 0.080 mg CuCl2/L and 1.26 mg CuO-NPs/L and 0.21 mg CuCl2/L and 20.17 mg CuO-NPs/L, respectively. At acute exposure, embryos exhibited several developmental abnormalities such as developmental delay, edema, axial flexure, and microcephaly. Larvae presented spasmodic contractions and weak movements. Regarding neurotoxicity, a significant increase in AChE activity at low concentrations as well as an inhibition of BChE activity at all tested concentrations was evidenced for both substances at acute exposure. Moreover, an increment in phospholipid and triglyceride levels was observed at the highest concentration of CuO-NPs (10 mg/L) at chronic exposure. The chromatographic separation of lipids showed no apparent differences in acylglycerols and free fatty acid bands, between the treatments and the control. The differences in toxicity between CuO-NPs and CuCl2 could be due to structural and physicochemical characteristics that influence their bioavailability and toxicity. Considering the exponential growth in the production and use of these substances, it is expected that the levels of contamination will rise considerably in the future, so that wildlife, particularly aquatic organisms, will be more increasingly exposed, representing a potential risk for their populations.
Assuntos
Cobre , Animais , Cobre/toxicidade , Poluentes Químicos da Água/toxicidade , Bioensaio , Nanopartículas Metálicas/toxicidade , Larva/efeitos dos fármacos , Bufo arenarum , Anuros/embriologiaRESUMO
The use of botanical insecticides has increased in recent years due to the demand for effective products, particularly against insects resistant to conventional insecticides. Among these is Aedes aegypti, a well-adapted mosquito to urban environments that opportunistically feeds on humans and animals, contributing to the spread of virus. We evaluated the potential of essential oils (EOs) extracted from Eucalyptus citriodora, Eucalyptus staigeriana, Eucalyptus caryophyllus, and Mentha arvensis in terms of their larvicidal activity against Ae. aegypti. EOs' compounds were determined using gas chromatography-mass spectrometry (GC-MS). Bioassays were performed on third instar larvae of Ae. aegypti to evaluate the larvicidal effects of EO dilutions in dimethyl sulfoxide (DMSO) at different concentrations. Mortality rates were observed over a 72-hour period to determine the efficacy of the treatments. Citronellal (86.64) predominated in E. citriodora, limonene in E. staigeriana (41.68), eugenol in E. caryophyllus (87.76), and menthol in M. arvensis (51.53%). EOs exhibited larvicidal activity from 10 ppm, with notable efficacy at 85 ppm, in which those from E. staigeriana and M. arvensis caused maximum mortality to Ae. aegypti larvae. Results revealed distinct efficacy patterns among EOs, with E. staigeriana displaying high toxicity within 24 h, achieving LC50 and LC95 values of 47.04 ppm and 97.35 ppm, respectively. Larvicidal effects within 1 h were observed for E. citriodora and E. caryophyllus. This study underscores larvicidal efficacy against Ae. aegypti, notably E. staigeriana, which had the lowest LC50 value. The findings indicate that the tested samples have potential for use as bioinsecticides.
Assuntos
Aedes , Cromatografia Gasosa-Espectrometria de Massas , Inseticidas , Larva , Óleos Voláteis , Animais , Aedes/efeitos dos fármacos , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Eucalyptus/química , Bioensaio , Dose Letal MedianaRESUMO
BACKGROUND: Acaricide resistance in cattle ticks is a significant concern in (sub)tropical regions, particularly Brazil. The Larval Packet Test (LPT) is the standard laboratory bioassay for resistance diagnosis, which requires triplicates of seven acaricidal dilutions plus controls to cover larval mortalities ranging between 0 and 100%. The value of the LPT lies in providing resistance ratios based on the ratio between the LC50 calculated with potentially resistant and susceptible ticks. However, LC50 ratios are difficult to translate into practical advice for farmers. Moreover, LPT requires laboratory facilities to maintain susceptible tick colonies, and it takes 6 weeks to obtain the larvae to be tested by LPT derived from engorged female ticks collected from cattle in the field. Our novel approach was twofold: first, we upgraded the LPT to the Resistance Intensity Test (RIT) by adopting the latest WHO guidelines for resistance detection in mosquitoes, which combines a 1 × recommended dose with 5 × and 10 × concentrated doses to reveal low, moderate and high resistance intensity, respectively. This reduced the number of test papers and tick larvae and, more importantly, provided relevant information on the resistance level. Our second innovative step was to abolish testing larvae entirely and expose partly engorged adult ticks to the same acaricidal doses immediately after removing them from cattle in the field. This resulted in the Rapid Tick exposure Test (RaTexT®), wherein partly engorged adult ticks were exposed to an acaricide-impregnated, specially designed matrix providing test results within 24 h. This approach directly compared resistance detection in tick larvae in the RIT with resistance in adult ticks in RaTexT®. METHODS: Laboratory validation was conducted in Brazil with resistant and susceptible colonies of Rhipicephalus microplus ticks. For field validation, adult R. microplus ticks collected from different cattle farms in Brazil were evaluated for resistance to RaTexT®, and the results regarding their larval progenies were compared with those for the RIT. Partly engorged adult ticks derived from cattle infested with laboratory and field strains of R. microplus were exposed to deltamethrin in RaTexT® containers, which contained six rows of four interconnected compartments, accommodating five to eight semi-engorged female ticks with a preferred size ranging between 5 and 8 mm. The corresponding larvae of each strain were exposed in the RIT to the same deltamethrin concentrations in filter papers. RESULTS: In RaTexT®, mortality in adult ticks from a resistant strain of R. microplus from Seropédica in Brazil was 38.4%, 54.2% and 75.0% at the 1 ×, 5 × and 10 × doses of deltamethrin, respectively. In RIT, mortality of larvae from the same resistant strain was 2.0%, 4.9% and 19.5% at 1 ×, 5 × and 10 × doses, respectively. The results of RaTexT® and RIT agreed since both tests identified a high level of resistance based on a cut-off of 90% mortality. In RaTexT®, mortality of adult ticks from a susceptible strain originating from Porto Alegre was 73.8%, 92.9% and 97.6% at the 1 ×, 5 × and 10 × doses, respectively. In RIT, mortality of larvae from the susceptible strain was 95.2%, 95.2% and 96.8% at the 1 ×, 5 × and 10 × doses, respectively. Interestingly, both tests identified a low number of unexpected resistant individuals in the susceptible strain since the mortality of neither larvae nor adults reached 100%. This effect remained unnoticed in the LPT, wherein a resistance ratio of 159.5 was found based on the LC50 of the resistant strain divided by the LC50 of the susceptible strain. Next, RaTexT® was compared with RIT using adult and larval ticks derived from three field strains of R. microplus in Brazil. RaTexT® detected high levels of resistance to deltamethrin in adult ticks in all strains, which was confirmed in larvae tested by the RIT. Both tests agreed on the same resistance level with significantly lower mortality rates in larvae than in adult ticks. CONCLUSIONS: RaTexT® is a novel rapid pen-site test for detecting acaricide resistance in adult livestock ticks. It potentially replaces laborious tests using larval ticks and provides results within 24 h relevant to acaricide resistance management of livestock ticks.
Assuntos
Acaricidas , Larva , Rhipicephalus , Infestações por Carrapato , Animais , Rhipicephalus/efeitos dos fármacos , Acaricidas/farmacologia , Brasil/epidemiologia , Larva/efeitos dos fármacos , Bovinos , Feminino , Infestações por Carrapato/veterinária , Doenças dos Bovinos/parasitologia , Resistência a Medicamentos , Bioensaio/métodos , Piretrinas/farmacologia , NitrilasRESUMO
Ampelozizyphus amazonicus Ducke, known as "saracura-mirá" in the Amazon rainforest, is valued for its traditional use in malaria prevention and treatment. The plant's roots and bark are employed for these purposes, while the wood is often overlooked. Given the global importance of leishmaniasis, this research focused on A. amazonicus anti-Leishmania amazonensis potential. The ethyl acetate extract from the bark (EAEB) exhibited the most effective inhibition of intracellular amastigote growth with IC50 7.0â µg mL-1 but showed high toxicity (CC50 9.0â µg mL-1). The wood ethanol (EW) and ethyl acetate (EAEW) extracts demonstrated promising results against L. amazonensis with IC50 15.8â µg mL-1 and 10.0â µg mL-1, CC50 50.5â µg mL-1 and 22.7â µg mL-1, respectively, with EW showing the greatest promise. High-speed countercurrent chromatography (HSCCC) combined with mass spectrometry (MS) off-line detection was employed for the bioassay-guided fractionation of EAEB and EAEW using HEMWat as a solvent system. These extracts showed to be rich in saponins and triterpenes, besides the presence of glycosylated flavonoids recently reported as minor compounds. The fractions obtained from HSCCC showed high toxicity. However, this technique proved effective in obtaining fractions with a high purity level, leading to the identification of a di-glycosylated triterpene saponin from EAEB, and melaleucic acid from EAEW. These findings highlight A. amazonicus as a potential source for developing new therapeutic alternatives for leishmaniasis and HSCCC as a technique enabling better separation efficiency of complex saponin matrices.
Assuntos
Distribuição Contracorrente , Leishmania , Extratos Vegetais , Animais , Camundongos , Antiprotozoários/farmacologia , Antiprotozoários/isolamento & purificação , Antiprotozoários/química , Bioensaio , Relação Dose-Resposta a Droga , Leishmania/efeitos dos fármacos , Testes de Sensibilidade Parasitária , Casca de Planta/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Extratos Vegetais/isolamento & purificação , Saponinas/química , Saponinas/farmacologiaRESUMO
The sediment of five mangrove in Pernambuco/Brazil was investigated to find a reference site for toxicity bioassays. Sediment characteristics, metal levels, and toxic effects on the nauplius of the copepod Tisbe biminiensis were studied. The sediment was composed by terrigenous muds and siliciclastic sands with medium to high organic matter contents. The FeAs association show most of the high concentrations and positive correlation among its constituents in the south. In the north, the Ca-Sr-La association is higher and exhibits positive correlation among its components that usually found in carbonate rocks. Very intense toxic effects were observed, mainly in the south, with >70 % reductions in development. As and Hg were positively correlated with mortality and decrease in development. The sediment quality at studied mangroves prevent their use as a reference site in bioassays. These could be linked to the direct/perennial contribution of geogenic sources associated with anthropogenic environmental impacts.
Assuntos
Copépodes , Ecotoxicologia , Monitoramento Ambiental , Sedimentos Geológicos , Poluentes Químicos da Água , Sedimentos Geológicos/química , Monitoramento Ambiental/métodos , Brasil , Animais , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Copépodes/efeitos dos fármacos , Bioensaio , Áreas AlagadasRESUMO
Toxoplasmosis is a worldwide zoonosis that affects warm-blooded animals, including humans. Wild animals can act as intermediate hosts of this pathogen; thus, this study aims to detect Toxoplasma gondii infection in invasive European brown hares in Brazil. For this, 72 wild European brown hares were captured from July 2020 to June 2022 in three Brazilian states: São Paulo, Paraná, and Rio Grande do Sul. The diagnostic of Toxoplasma gondii infection was performed by bioassay in mouse, histopathology in Hematoxylin-Eosin-stained tissue sections (brain, liver, lungs, kidneys, and small intestine), serology by IFAT, and molecular techniques by conventional PCR and qPCR. The combined prevalence of the different diagnostic methods was 51.4% (37/72, CI= 40.1 - 62.6 %), and there was no statistical difference between sexes, age range, or geographical region of the hosts. Mouse bioassay was the technique that detected more positive hares. To our knowledge, this is the first confirmation of Toxoplasma gondii infection in invasive European brown hares in Brazil. These animals act as reservoirs and potential infection source for carnivores and other wild and domestic animals, including humans, thus contributing to perpetuate the disease cycle in São Paulo, Paraná, and Rio Grande do Sul States. Research such as the present study is necessary to raise awareness about the role of animals in the disease cycle.
Assuntos
Lebres , Toxoplasma , Toxoplasmose Animal , Animais , Brasil/epidemiologia , Toxoplasmose Animal/parasitologia , Toxoplasmose Animal/epidemiologia , Toxoplasmose Animal/diagnóstico , Lebres/parasitologia , Toxoplasma/isolamento & purificação , Camundongos , Feminino , Masculino , Prevalência , BioensaioRESUMO
Ecotoxicological tools, namely biomarkers and bioassays, may provide insights on the ecological quality status of mangroves under restoration. We investigated how 1) physicochemical parameters and water bioassays using Artemia franciscana; and 2) quantification of sublethal (osmoregulatory capacity, biochemical, and oxidative stress) and individual biomarkers (density, length-weight relationship [LWR], parasitic prevalence) in the sentinel fiddler crab Minuca rapax, can improve restoration indicators in mangroves from the Yucatán Peninsula, Southern Gulf of Mexico. We showed that water quality was improved with restoration, but still presented toxicity. Regarding sublethal biomarkers, M rapax from restored areas lower osmotic regulatory capacity, higher oxidative stress, and showed lipid peroxidation. As to the individual biomarkers, the density, LWR, and the prevalence of parasites in M. rapax was higher in restored areas. The use of bioassays/biomarkers were useful as early warning indicators to better assess the health of mangroves under restoration.
Assuntos
Ecotoxicologia , Monitoramento Ambiental , Áreas Alagadas , Animais , México , Monitoramento Ambiental/métodos , Biomarcadores , Braquiúros , Poluentes Químicos da Água/toxicidade , Poluentes Químicos da Água/análise , Qualidade da Água , Artemia , Bioensaio , Recuperação e Remediação Ambiental , Estresse Oxidativo , Golfo do MéxicoRESUMO
Assisted reproductive techniques are routinely used in livestock species to increase and enhance productivity. Ovarian hyperstimulation is a process that currently relies on administering pituitary-derived follicle-stimulating hormone (FSH) or equine chorionic gonadotropin in combination with other hormones to promote the maturation of multiple follicles and thereby achieve superovulation. The use of partially purified preparations of FSH extracted from natural sources is associated with suboptimal and variable results. Recombinant FSH (rFSH) has been produced in a variety of heterologous organisms. However, attaining a bioactive rFSH of high quality and at low cost for use in livestock remains challenging. Here we report the production and characterization of a single chain bovine rFSH consisting of the ß- and α-subunit fused by a polypeptide linker (scbFSH) using Leishmania tarentolae as heterologous expression system. This unicellular eukaryote is non-pathogenic to mammals, can be grown in bioreactors using simple and inexpensive semisynthetic media at 26°C and does not require CO2 or bovine serum supplementation. Stable cell lines expressing scbFSH in an inducible fashion were generated and characterized for their productivity. Different culture conditions and purification procedures were evaluated, and the recombinant product was biochemically and biologically characterized, including bioassays in an animal model. The results demonstrate that L. tarentolae is a suitable host for producing a homogeneous, glycosylated and biologically active form of scbFSH with a reasonable yield.
Assuntos
Leishmania , Feminino , Animais , Cavalos , Leishmania/genética , Bioensaio , Reatores Biológicos , Linhagem Celular , Hormônio Foliculoestimulante , MamíferosRESUMO
This study aimed to detect Toxoplasma gondii in artisanal salted meat products sold in street markets in the Ilhéus-Itabuna microregion and to assess the salt concentration used in their preparation and its influence on the parasite's viability. A total of 125 samples of various artisanal meat products sold in street markets located in the Ilhéus-Itabuna microregion were collected during 2021. Serological analysis using indirect hemagglutination (HAI) and molecular analysis (PCR) were performed on these samples to detect the presence of the parasite. Möhr's method was utilized to determine the sodium chloride concentration in the samples. Of all samples, 21 were subjected to a bioassay in albino mice to verify the viability of possible tissue cysts. Among the 125 meat products, 10 (8%) tested positive in the serological analysis including four cured pork sausages, five beef sun-dried meats, and one mixed fresh sausage (pork and chicken). None of 125 samples tested positive in the molecular analysis. On bioassay, all mice tested negative for the presence of the parasite. The NaCl concentration in the positive samples ranged from 2.9% to 8%. The results demonstrated that the salt concentration in the collected samples was sufficient to inactivate the parasite T. gondii.
Assuntos
Doenças dos Bovinos , Produtos da Carne , Doenças dos Roedores , Toxoplasma , Toxoplasmose Animal , Bovinos , Animais , Camundongos , Produtos da Carne/parasitologia , Cloreto de Sódio , Carne/parasitologia , Bioensaio/veterináriaRESUMO
BACKGROUND: Developing disposable paper-based devices has positively impacted analytical science, particularly in developing countries. Some benefits of those devices include their versatility, affordability, environmentally friendly, and the possibility of being integrated with portable electrochemical or colorimetric detectors. Paper-based analytical devices (PADs) comprising circular zones and microfluidic networks have been successfully employed in the analytical chemistry reign. However, the combination of the stencil-printing method and alternative binder has not been satisfactorily explored for fabricating colorimetric paper devices. RESULTS: We developed PADs exploring the stencil printing approach and glass varnish as the hydrophobic chemical agent. As a proof-of-concept, the colorimetric assay of salivary α-amylase (sAA) was performed in saliva samples. Through the scanning electron microscopy measurements, it was possible to indicate satisfactory definitions between native fibers and barrier, and that the measured values for the channel width revealed suitable fidelity (R2 = 0.99) with the nominal widths (ranging from 400 to 5000 µm). The proposed hydrophobic barrier exhibited excellent chemical resistance. The analytical applicability for detecting sAA revealed linear behavior in the range from 2 to 12 U mL-1 (R2 = 0.99), limit of detection of 0.75 U mL-1, reproducibility (RSD ≤2.4%), recovery experiments ranged from 89 to 108% and AGREE response (0.86). In addition, the colorimetric analysis of sAA in four different saliva samples demonstrated levels ranging from 202 to 2080 U mL-1, which enabled monitoring the absence and presence of periodontitis. SIGNIFICANCE: This report has presented the first use of a self-adhesive mask and glass varnish for creating circular zones and microfluidic architectures on paper without using thermic or UV curing treatments. Also, the proposed analytical methodology for detecting sAA exhibited suitable ecological impact considering the AGREE tool. We believe the proposed fabrication of paper devices emerges as a novel, simple, high-fidelity microfluidic channel and portable analytical approach for colorimetric sensing.
Assuntos
Colorimetria , alfa-Amilases Salivares , Reprodutibilidade dos Testes , Bioensaio , VidroRESUMO
Abstract Introduction: Short-term gametes storage is an inexpensive and simple technique that allows the use of the same batch of eggs or sperm at different times, maximizing the application of research protocols and the use of gametes in production. Arbacia dufresnii is a sea urchin species with proven aquaculture potential and already used in the nutraceutical industry. Aging of its gametes is unknown and is a needed information to scale up the production. Objective: Determine the effect of male and female gamete aging on the fertilization success of Arbacia dufresnii. This will allow optimizing the use of gametes after collection decoupling spawning from fertilization. Methods: A. dufresnii individuals were induced to spawn and gametes were kept at 12 ± 1 °C throughout each bioassay. Sperm was separated into two treatments: activated sperm in seawater (AS), and dry sperm (DS). Two bioassays were made: Bioassay 1 evaluated the effect of time on fertility by performing fertilization tests at 0 h, 24 h, 48 h, 72 h, and 96 h after spawning. Bioassay 2 evaluated the contribution of each type of aged gamete on fertility, combining aged gametes (96 h) with fresh gametes (0 h). Results: Bioassay 1: the fertilization success obtained by combining eggs (E) with AS or DS presented important differences. While the fertilization success remained acceptable (greater than 50 %) for up to 72 h using ExDS, it only remained acceptable for up to 48 h using ExAS. Bioassay 2: acceptable fertilization success was found by combining aged E (96 h) with fresh sperm, or aged DS (96 h) with fresh E, but not using aged AS with fresh E. Conclusions: The findings of this work show that fertilization success in A. dufresnii gametes remains relatively unchanged for up to 48 h after spawning when combining ExAS, and for up to 72 h when combining ExDS. However, when combining aged E or aged DS with a fresh gamete, post-collection fertilization can be extended up to 96 h. In this work, the first steps have been taken to understand the conservation time of A. dufresnii gametes with minimum intervention.
Resumen Introducción: El almacenamiento de gametos a corto plazo es una técnica económica y sencilla que permite utilizar el mismo lote de óvulos o espermatozoides en diferentes momentos, maximizando la aplicación de protocolos de investigación y el uso de gametos en la producción. Arbacia dufresnii es una especie con probado potencial acuícola como fuente de gametos para la industria nutracéutica. Sin embargo, se desconoce el envejecimiento de sus gametos y es una información necesaria para escalar la producción. Objetivo: Determinar el efecto del envejecimiento de los gametos masculinos y femeninos en el éxito de la fecundación de Arbacia dufresnii con el fin de optimizar el aprovechamiento de los gametos después de la recolecta desincronizando el desove de la fecundación. Métodos: Se indujo el desove de individuos de A. dufresnii y los gametos se mantuvieron a 12 ± 1 °C durante cada bioensayo. El esperma se separó en dos tratamientos: esperma activado en agua de mar (AS) y esperma seco (DS). Se realizaron dos bioensayos: El Bioensayo 1 evaluó el efecto del tiempo sobre la fertilidad realizando pruebas de fecundación a las 0 h, 24 h, 48 h, 72 h y 96 h después del desove. El bioensayo 2 evaluó la contribución de cada tipo de gameta envejecida (96 h) sobre la fertilidad, combinando gametos envejecidas (96 h) con gametos frescas (0 h). Resultados: Bioensayo 1: el éxito de fecundación obtenido combinando huevos (E) con AS o DS presentó diferencias importantes. Si bien el éxito de la fecundación se mantuvo aceptable (más del 50 %) durante un máximo de 72 h con ExDS, solo permaneció aceptable hasta 48 h con ExAS. Bioensayo 2: se encontró un éxito de fecundación aceptable combinando E envejecidos (96 h) con esperma fresco, o DS envejecido (96 h) con E fresco (0 h), pero no usando AS envejecido con E fresco (0 h). Conclusiones: Los hallazgos de este trabajo muestran que el éxito de la fecundación en los gametos de A. dufresnii permanece relativamente sin cambios hasta 48 h después del desove cuando se combina ExAS, y hasta 72 h cuando se combina ExDS. Sin embargo, cuando se combina E envejecido o DS envejecido con un gameto fresco, el tiempo entre la recolección y la fecundación puede extenderse hasta 96 h. En este trabajo se han dado los primeros pasos para entender el tiempo de conservación de los gametos de A. dufresnii con mínima intervención.
Assuntos
Animais , Reprodução , Ouriços-do-Mar/embriologia , Bioensaio , Equinodermos/crescimento & desenvolvimento , Células Germinativas/crescimento & desenvolvimentoRESUMO
In this study, poly (lactic-co-glycolic acid) (PLGA) microparticles loaded with cannabidiol (CBD) were synthesized (PLGA@CBD microparticles) and embedded up to 10 wt% in a chondroitin sulfate/polyvinyl alcohol hydrogel matrix. In vitro chemical, physical, and biological assays were carried out to validate the potential use of the modified hydrogels as biomaterials. The microparticles had spherical morphology and a narrow range of size distribution. CBD encapsulation efficiency was around 52%, loading was approximately 50%. Microparticle addition to the hydrogels caused minor changes in their morphology, FTIR and thermal analyses confirmed these changes. Swelling degree and total porosity were reduced in the presence of microparticles, but similar hydrophilic and degradation in phosphate buffer solution behaviors were observed by all hydrogels. Rupture force and maximum strain at rupture were higher in the modified hydrogels, whereas modulus of elasticity was similar across all materials. Viability of primary human dental pulp cells up to 21 days was generally not influenced by the addition of PLGA@CBD microparticles. The control hydrogel showed no antimicrobial activity against Staphylococcus aureus, whereas hydrogels with 5% and 10% PLGA@CBD microparticles showed inhibition zones. In conclusion, the PLGA@CBD microparticles were fabricated and successfully embedded in a hydrogel matrix. Despite the hydrophobic nature of CBD, the physicochemical and morphological properties were generally similar for the hydrogels with and without the CBD-loaded microparticles. The data reported in this study suggested that this original biomaterial loaded with CBD oil has characteristics that could enable it to be used as a scaffold for tissue/cellular regeneration.
Assuntos
Canabidiol , Humanos , Porosidade , Materiais Biocompatíveis , Bioensaio , HidrogéisRESUMO
This study described the growth, morphometric, biomechanical, and chemical properties of the femur, tibiotarsus, and tarsometatarsus of European and Japanese quail. Analyses were performed at 13 and 15 days of incubation, at hatch, and at 4, 7, 10, 14, 21, 28, and 35 days post-hatch (n=6/subspecies/period). Bone specimens were analyzed by cone-beam computed tomography, biomechanical assays, chemical analyses, and histomorphometry. Variables were fitted by the Gompertz function and its derivative or assessed using the analysis of variance. Analysis of the derivative of Gompertz curves showed that the growth behavior of the tarsometatarsal bone was similar between quail subspecies, and the femur and tibiotarsus of European quail increased first in width and then in length, whereas the opposite occurred in Japanese quail. There was an interaction between quail subspecies and days of growth on femoral, tarsometatarsal, and tibiotarsal bone densities. Femoral and tibiotarsal cross-sectional areas were influenced by the interaction of quail subspecies and day of growth. Interaction effects were significant for breaking strength and phosphorus percentage. European and Japanese quail have different femoral and tibiotarsal growth patterns, especially in the first few days after hatching, whereas tarsometatarsal growth is similar between subspecies.
Assuntos
Coturnix , Codorniz , Animais , Fêmur/diagnóstico por imagem , Proliferação de Células , BioensaioRESUMO
Visceral leishmaniasis (VL) requires diagnostic assays to complement clinical suspicion. However, there is no standardization of a diagnostic flow using available assays. This study aimed to evaluate the performance of parasitological, molecular, and serological assays for diagnosing VL and propose a diagnostic flow based on performance, practicality, and invasiveness. We conducted a study of 10-year (2010-2020) routine diagnoses of VL at the Brazilian National Reference Laboratory. We propose a diagnostic flow where individuals suspected of VL are initially screened for antibodies using an immunochromatographic test (ICT) with rK39 antigen on the nitrocellulose membrane. This is followed by a blood polymerase chain reaction (PCR) for Leishmania sp. kDNA and direct parasitological exam and/or PCR in bone marrow aspirate. A positive result in any of these assays can define a VL case. If clinical suspicion persists in negative individuals, the diagnostic flow should be repeated. The proposed flow has the potential to standardize and improve the diagnosis of VL. It reduces the need for invasive tests without compromising diagnostic accuracy.
Assuntos
Leishmaniose Visceral , Humanos , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/epidemiologia , Brasil/epidemiologia , Algoritmos , Anticorpos , BioensaioRESUMO
Ciguatera, a global issue, lacks adequate capacity for ciguatoxin analysis in most affected countries. The Caribbean region, known for its endemic ciguatera and being home to a majority of the global small island developing states, particularly needs established methods for ciguatoxin detection in seafood and the environment. The radioligand receptor binding assay (r-RBA) is among the in vitro bioassays currently used for ciguatoxin analysis; however, similarly to the other chemical-based or bioassays that have been developed, it faces challenges due to limited standards and interlaboratory comparisons. This work presents a single laboratory validation of an r-RBA developed in a Cuban laboratory while characterizing the performance of the liquid scintillation counter instrument as a key external parameter. The results obtained show the assay is precise, accurate and robust, confirming its potential as a routine screening method for the detection and quantification of ciguatoxins. The new method will aid in identifying high-risk ciguatoxic fish in Cuba and the Caribbean region, supporting monitoring and scientific management of ciguatera and the development of early warning systems to enhance food safety and food security, and promote fair trade fisheries.
Assuntos
Ciguatera , Ciguatoxinas , Animais , Ciguatoxinas/análise , Ciguatera/diagnóstico , Peixes , Ligação Proteica , BioensaioRESUMO
The roundworm Caenorhabditis elegans (C. elegans) has become a powerful tool to evaluate the deleterious effects of early-life exposure to xenobiotics, including metals. The present chapter describes a detailed protocol for developmental lead (Pb)-exposure in C. elegans. Preliminary assays as well as the final procedure are described in detail. In addition, further protocols aimed to assess ethanol exposure at later stages of life demonstrate the impact of this drug on locomotor behavior, revealing the enduring effects that Pb can imprint on this organism when exposure occurs during development.
Assuntos
Caenorhabditis elegans , Chumbo , Animais , Chumbo/toxicidade , Bioensaio , Etanol/toxicidadeRESUMO
The essential oils of Lippia citriodora (Ort.) and Lippia origanoides (Kunth) have shown antimicrobial activity associated with mastitis. The objective of this study was to evaluate its ecotoxic effect with the Artemia salina bioassay and the prevention of mastitis through an in vivo test in cattle (n=20) with a product based on these oils using a conventional product as a control. Contact hypersensitivity, the effect on somatic cells, and residuality in mil k samples were evaluated. The results of the Artemia salina bioassay were 10.05 and 19.36 (µg/mL) respectively. No negative effects or contact hypersensitivity were observed, and no residual metabolites were found in post - test milk. The somatic cell count showed 75% effectiveness in the prevention of mastitis with essential oils compared to 62.5% with the conventional product. The evaluated formulation could be used in the prevention of bovine mastitis safely, further investigation is required.
Los aceites esenciales de Lippia citriodora (Ort.) y Lippia origanoides (Kunth), han mostrado acti vidad antimicrobiana asociada a la mastitis. El objetivo de este estudio fue evaluar su efecto ecotóxico con el bioensayo Artemia salina y la prevención de mastitis mediante un ensayo in vivo en bovinos (n=20) con un producto a base de estos aceites utiliz ando como control un producto convencional. Se evaluó la hipersensibilidad de contacto, efecto en células somáticas y residualidad en muestra de leche. Los resultados del bioensayo de Artemia salina fueron 10,05 y 19,36 (µg/mL) respectivamente. No se obser varon efectos negativos, ni hipersensibilidad de contacto, y no se encontraron metabolitos residuales en leche posterior al ensayo. El conteo de células somáticas mostró efectividad en la prevención de mastitis del 75% con aceites esenciales frente al 62.5 % del producto convencional. La formulación evaluada podría ser utilizada en la prevención de la mastitis bovina de forma segura, se requiere profundizar en la investigación.
Assuntos
Óleos Voláteis/administração & dosagem , Lippia/química , Mastite Bovina/prevenção & controle , Artemia , Terpenos/análise , Bioensaio , Óleos Voláteis/química , Hipersensibilidade , Cromatografia Gasosa-Espectrometria de MassasRESUMO
The clinical efficacy of many existing antibiotics is currently threatened by the emergence of microbial resistance. This recognized worldwide situation prompts to greater efforts to discover antimicrobial agents of natural origin, including plant sources. The objective of this work was to evaluate the antimicrobial activities of extracts, fractions and pure compounds from Rauhia multiflora using a bioguided complementary fractionation, contributing also to explain some traditional uses of this genus. Some subfractions showed antimicrobial activity against the Gram-negative and Gram-positive bacteria. Galantamine was identified and isolated as the main alkaloid, together with two additional structures of the same skeleton. Characterization by GC-MS revealed the presence of twelve galantamine-type and four crinane-type compounds. The tentative structure of one of the galantamine-type skeletons is proposed here for the first time. Altogether, these results support the use of Rauhia genus to inhibit bacterial growth.