RESUMO
Several pathogenic Escherichia coli strains cause diarrhea. Enteroaggregative E. coli (EAEC) strains are one of the diarrheagenic pathotypes. EAEC cells form a "stacked-brick" arrangement over the intestinal epithelial cells. EAEC isolates express, among other virulence determinants, the AggR transcriptional activator and the aggregative adherence fimbriae (AAF). Overexpression of the aggR gene results in increased expression of virulence factors such as the aff genes, as well as several genes involved in specific metabolic pathways such as fatty acid degradation (fad) and arginine degradation (ast). To support the hypothesis that induction of the expression of some of these pathways may play a role in EAEC virulence, in this study we used a murine infection model to evaluate the impact of the expression of these pathways on infection parameters. Mice infected with a mutant derivative of the EAEC strain 042, characterized by overexpression of the aggR gene, showed increased disease symptoms compared to those exhibited by mice infected with the wild type (wt) strain 042. Several of these symptoms were not increased when the infecting mutant, which overexpressed aggR, lacked the fad and ast pathways. Therefore, our results support the hypothesis that different metabolic pathways contribute to EAEC virulence.
Assuntos
Infecções por Escherichia coli , Proteínas de Escherichia coli , Escherichia coli , Fezes , Microbioma Gastrointestinal , Fatores de Virulência , Animais , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/metabolismo , Camundongos , Fezes/microbiologia , Escherichia coli/patogenicidade , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Ácidos Graxos Voláteis/metabolismo , Mutação , Virulência/genética , Feminino , Modelos Animais de Doenças , Regulação Bacteriana da Expressão Gênica , Biomarcadores , TransativadoresRESUMO
Layers of pulmonary lipids on an aqueous substrate at non-equilibrium conditions can decrease the surface tension of water to quite low values. This is connected with different relaxation processes occurring at the interface and the associated changes in the surface layer structure. Results of measurements by the combination of methods like surface rheology, ellipsometry, Brewster angle microscopy, and IRRAS for spread layers of lipid mixtures open a possibility to specify the dynamics of structural changes at conditions close to the physiological state. At sufficiently low surface tension values (below 5 mN/m) significant changes in the ellipsometric signal were observed for pure DPPC layers, which can be related to a transition from 2D to 3D structures caused by the layer folding. The addition of other lipids can accelerate the relaxation processes connected with squeezing-out of molecules or multilayer stacks formation hampering thereby a decrease of surface tension down to low values corresponding to the folding of the monolayer.
Assuntos
Pulmão , Microscopia , Tensão Superficial , Pulmão/química , Lipídeos/química , Propriedades de Superfície , Água/química , 1,2-Dipalmitoilfosfatidilcolina/químicaRESUMO
Antecedentes: el intento de suicidio es el principal factor de riesgo de muerte por suicidio. La Organización Mundial de la Salud sugiere grupos de apoyo como intervención para esta población. Objetivo: Este estudio tuvo como objetivo determinar la eficacia de los grupos de apoyo de pares para sobrevivientes de intento de suicidio (SOSA). Método: Revisión sistemática (PROSPERO ID: CRD42022307581). Resultados: En total se identificaron 946 artículos potenciales, se revisaron 81 textos completos y se incluyó un artículo. El artículo informa sobre un estudio piloto abierto con evaluaciones pre y post intervención, sin grupo de control y con alto riesgo de sesgo. Esta es una intervención prometedora, porque los resultados mostraron una disminución de la ideación suicida (d=0,33), y del intento de suicidio (d=0,31). El pequeño número de investigaciones empíricas limita las generalizaciones. Conclusión: El nivel de certeza de la evidencia es bajo (baja certeza), por lo tanto, el grado de recomendación corresponde a evidencia insuficiente (I), para recomendar esta estrategia para las políticas públicas. En este artículo se analizan las razones de estos resultados y los posibles caminos para avanzar en este campo.
Background: Suicide attempt is the main risk factor for death by suicide. The World Health Organization (WHO) suggests support groups as an intervention for this population. Objective: This study aimed to assess the efficacy of peer-support groups for survivors of suicide attempt (SOSA). Method: Systematic review (PROSPERO ID: CRD42022307581). Results: In total, 946 potential articles were identified, 81 full texts were reviewed, and one article was included. The article reported an open-label pilot study with pre- and post-intervention evaluations, without a control group, and with a high risk of bias. This is a promising intervention because the results showed decreased suicidal ideation (d=0.33) and suicide attempt (d=0.31). The small number of empirical investigations limit generalizations. Conclusion: The level of certainty of evidence is low (low certainty); therefore, the grade of recommendation corresponds to insufficient evidence (I) to recommend this strategy for public policies. The reasons for these results and possible paths to advance the field are discussed in this article.
RESUMO
We developed a simple linear stochastic model for Dalbulus maidis dependent exclusively on temperature, whose parameters were determined from published field and laboratory studies performed at different temperatures. This model takes into account the principal stages and events of the life cycle of this pest, which is vector of maize diseases. We implemented the effect of distributed delays or Linear Chain Trick (LCT) considering a fixed number of sub-stages for egg and nymph stages of Dalbulus maidis in order to accurately represent what is observed in nature. A sensitivity analysis allows us to observe that the speed of the dynamics is sensitive to changes in the development rates, but not to the longevity of each stage or the fecundity, which almost exclusively affect insect abundance. We used our model to study its predictive and explanatory capacity considering a published experiment as a case study. Although the simulation results show a behavior qualitatively equivalent to that observed in the experimental results it is not possible to explain accurately the magnitude, nor the times in which the maximum abundances of second-generation nymphs and adults are reached. Therefore, we evaluated three possible scenarios for the insect that allow us to glimpse some of the advantages of having a computational model in order to find out what processes, taken into account in the model, may explain the differences observed between published experimental results and model results. The three proposed scenarios, based on variations in the parameterized rates of the model, can satisfactorily explain the experimental observations. We observed that in order to better simulate the experimental results it is not necessary to modify fecundity or mortality rates. However, it is necessary to accelerate the average development rates of our model by 20 to 40 %, compatible with extreme values of the rates close to the upper edges of the confidence bands of our parameterization rate curves, according to insects with faster development rates already reported in literature.
Assuntos
Hemípteros , Insetos Vetores , Doenças das Plantas , Zea mays , Animais , Hemípteros/crescimento & desenvolvimento , Doenças das Plantas/etiologia , Insetos Vetores/crescimento & desenvolvimentoRESUMO
Among the isoflavones and isoflavone-derived metabolites, equol, which in the human gut is synthesised from daidzein by minority bacterial populations, shows the strongest estrogenic and antioxidant activity. The beneficial effects on human health of isoflavone consumption might be partially or indeed totally attributable to this equol. Although some of the bacterial strains involved in its formation have been identified, the interplay between the composition and functionality of the gut microbiota and equol producer phenotype has hardly been studied. In this study, after shotgun metagenomic sequencing, different pipelines for the taxonomic and functional annotation of sequencing data were used in the search for similarities and differences in the faecal metagenome of equol-producing (n=3) and non-producing (n=2) women, with special focus on equol-producing taxa and their equol-associated genes. The taxonomic profiles of the samples differed significantly depending on the analytical method followed, although the microbial diversity detected by each tool was very similar at the phylum, genus and species levels. Equol-producing taxa were detected in both equol producers and non-producers, but no correlation between the abundance of equol-producing taxa and the equol producing/non-producing phenotype was found. Indeed, functional metagenomic analysis was unable to identify the genes involved in equol production, even in samples from equol producers. By aligning equol operons with the collected metagenomics data, a small number of reads mapping to equol-associated sequences were recognised in samples from both equol producers and equol non-producers, but only two reads mapping onto equol reductase-encoding genes in a sample from an equol producer. In conclusion, the taxonomic analysis of metagenomic data might not be suitable for detecting and quantifying equol-producing microbes in human faeces. Functional analysis of the data might provide an alternative. However, to detect the genetic makeup of the minority gut populations, more extensive sequencing than that achieved in the present study might be required.
RESUMO
Archanara neurica (Hübner, 1808) is recorded for the first time from the Iberian Peninsula. The Iberian population represent a link between central European, including French, and Moroccan populations. Male internal genitalia are comparatively described. DNA barcode is presented and compared with those of the other European Archanara, Lenisa and Globia species, formerly considered congeneric. An analysis based on the COI mitochondrial gene provisionally supports the morphologically proposed statement that recognize the three mentioned taxa at the generic level.
Assuntos
Lepidópteros , Mariposas , Masculino , Animais , Código de Barras de DNA Taxonômico , Europa (Continente) , DNA , Genitália Masculina , GenitáliaRESUMO
The genus Apaidia Hampson, 1900 is a relict Western Mediterranean genus in the South-western part of Europe and the North-western areas of the Mediterranean Africa comprising so far three species, Apaidia rufeola (Rambur, 1832), Apaidia mesogona (Godart, [1824]) and Apaidia barbarica Legrand, 1939. According to the examined material, COI mitochondrial DNA sequences and adult morphology integration supports the existence of three main lineages of Apaidia with sequence divergence rates of approximately 4.5%, which are within the range reported for other well-defined insect species. In addition, we recovered three different BINS, suggesting the presence of different species with unique and specific identifier for A. mesogona (AEC6797), A. rufeola (AEI9539), and the Iberian-Balearic A. barbarica (AEI9540). This study contributes to a better understanding of the taxonomy of the genus Apaidia and challenges future revision of this genus in Northern Africa, as well as the presence of the Apaidia species in Western Mediterranean islands and populations located in Italy.
Assuntos
Código de Barras de DNA Taxonômico , Mariposas , Animais , Filogenia , DNA Mitocondrial/genética , Mariposas/genéticaRESUMO
HYPOTHESIS: A broad range of phenomena, such as emulsification and emulsion stability, foam formation or liquid evaporation, are closely related to the dynamics of adsorbing colloidal particles. Elucidation of the mechanisms implied is key to a correct design of many different types of materials. EXPERIMENTS: Microspheres forced to rotate near a fluid interface exhibit a roto-translational hydrodynamic mechanism that is hindered by capillary torques as soon as the particles protrude the interface. Under these conditions, the time evolution in the ratio of moving spheres provides a direct description of the adsorption kinetics, while microscopy monitoring of particle acceleration\deceleration informs about the adsorption\desorption dynamics. In this work, the proposed strategy is applied at an air/water interface loaded with spherical magnetic particles negatively charged, forced to rotate by the action of a rotating magnetic field. FINDINGS: The proposed method enables the adsorption/desorption dynamics to be followed during the earliest phase of the process, when desorption of a small fraction of particles is detected, as well as to estimate approximated values of the adsorption/desorption constants. The results obtained show that the addition of a monovalent salt or a cationic (anionic) surfactant promotes (inhibits) both adsorption and formation of permanent bonds between particles.
Assuntos
Tensoativos , Água , Adsorção , Emulsões , Cinética , Tensoativos/química , Água/químicaRESUMO
INTRODUCTION: Malignant gastric outlet obstruction is a condition that alters patient quality of life, conditioning progressive malnutrition. However, self-expanding metal stents (SEMSs) and surgical gastrojejunostomy (SGJ) are palliative options in patients with unresectable disease. AIM: To characterize patients diagnosed with malignant gastric outlet obstruction requiring SEMS placement or SGJ. MATERIALS AND METHODS: Sequential non-probability convenience sampling was conducted and included 68 patients, 40 of whom had SEMS placement and 28 of whom underwent SGJ. RESULTS: Patients sought medical consultations for the symptoms of vomiting, abdominal pain, weight loss, and upper gastrointestinal bleeding. Ninety-five percent of the patients in the SEMS group and 64.3% in the SGJ group presented with metastasis. Technical and clinical success, patency duration, and number of patients with no complications were greater in the SGJ group. Mean survival in days was 88 (SD⯱â¯21) in the SEMS group versus 501 (SD⯱â¯122) in the SGJ group. The log-rank test detected a statistically significant difference between subgroups (pâ¯=â¯0.00). CONCLUSION: SGJ has greater technical and clinical success rates but SEMS placement continues to be utilized in distal gastric cancer, especially in cases in which surgery is not an option.
Assuntos
Obstrução da Saída Gástrica , Neoplasias Gástricas , Colômbia , Obstrução da Saída Gástrica/etiologia , Obstrução da Saída Gástrica/cirurgia , Hospitais , Humanos , Qualidade de Vida , Estudos Retrospectivos , Neoplasias Gástricas/complicações , Resultado do TratamentoRESUMO
Drug resistance is a worldwide problem affecting all pathogens. The human fungal pathogen Aspergillus fumigatus coexists in the environment with other fungi targeted by crop protection compounds, being unintentionally exposed to the selective pressure of multiple antifungal classes and leading to the selection of resistant strains. A. fumigatus azole-resistant isolates are emerging in both clinical and environmental settings. Since their approval, azole drugs have dominated clinical treatment for aspergillosis infections and the agriculture fungicide market. However, other antifungal classes are used for crop protection, including benzimidazoles (methyl benzimidazole carbamates [MBCs]), strobilurins (quinolone oxidation inhibitors [QoIs]), and succinate dehydrogenase inhibitors (SDHIs). Mutations responsible for resistance to these fungicides have been widely researched in plant pathogens, but resistance has not been explored in A. fumigatus. In this work, the genetic basis underlying resistance to MBCs, QoIs, and SDHIs was studied in azole-susceptible and -resistant A. fumigatus strains. E198A/Q and F200Y mutations in ß-tubulin conferred resistance to MBCs, G143A and F129L substitutions in cytochrome b conferred resistance to QoIs, and H270R/Y mutations in SdhB conferred resistance to SDHIs. Characterization of susceptibility to azoles showed a correlation between strains resistant to these fungicides and the ones with tandem-repeat (TR)-based azole resistance mechanisms. Whole-genome sequencing analysis showed a genetic relationship among fungicide multiresistant strains, which grouped into subclusters that included only strains carrying the TR-based azole resistance mechanisms, indicating a common ancestor/evolution pattern and confirming the environmental origin of this type of azole-resistant A. fumigatus.
Assuntos
Aspergillus fumigatus , Fungicidas Industriais , Antifúngicos/farmacologia , Aspergillus fumigatus/genética , Azóis/farmacologia , Sistema Enzimático do Citocromo P-450/genética , Farmacorresistência Fúngica/genética , Proteínas Fúngicas/genética , Fungicidas Industriais/farmacologia , Humanos , Testes de Sensibilidade MicrobianaRESUMO
The airborne fungus Aspergillus fumigatus poses a serious health threat to humans by causing numerous invasive infections and a notable mortality in humans, especially in immunocompromised patients. Mould-active azoles are the frontline therapeutics employed to treat aspergillosis. The global emergence of azole-resistant A. fumigatus isolates in clinic and environment, however, notoriously limits the therapeutic options of mould-active antifungals and potentially can be attributed to a mortality rate reaching up to 100 %. Although specific mutations in CYP 51A are the main cause of azole resistance, there is a new wave of azole-resistant isolates with wild-type CYP 51A genotype challenging the efficacy of the current diagnostic tools. Therefore, applications of whole-genome sequencing are increasingly gaining popularity to overcome such challenges. Prominent echinocandin tolerance, as well as liver and kidney toxicity posed by amphotericin B, necessitate a continuous quest for novel antifungal drugs to combat emerging azole-resistant A. fumigatus isolates. Animal models and the tools used for genetic engineering require further refinement to facilitate a better understanding about the resistance mechanisms, virulence, and immune reactions orchestrated against A. fumigatus. This review paper comprehensively discusses the current clinical challenges caused by A. fumigatus and provides insights on how to address them.
RESUMO
The increasing use of metal oxide nanoparticles (MONPs) as TiO2 NPs or ZnO NPs has led to environmental release and human exposure. The respiratory system, effects on lamellar bodies and surfactant protein A (SP-A) of pneumocytes, can be importantly affected. Exposure of human alveolar epithelial cells (A549) induced differential responses; a higher persistence of TiO2 in cell surface and uptake (measured by Atomic Force Microscopy) and sustained inflammatory response (by means of TNF-α, IL-10, and IL-6 release) and ROS generation were observed, whereas ZnO showed a modest response and low numbers in cell surface. A reduction in SP-A levels at 24 h of exposure to TiO2 NPs (concentration-dependent) or ZnO NPs (the higher concentration) was also observed, reversed by blocking the inflammatory response (by the inhibition of IL-6). Loss of SP-A represents a relevant target of MONPs-induced inflammatory response that could contribute to cellular damage and loss of lung function.
Assuntos
Células Epiteliais Alveolares/efeitos dos fármacos , Nanopartículas/toxicidade , Proteína A Associada a Surfactante Pulmonar/antagonistas & inibidores , Titânio/toxicidade , Óxido de Zinco/toxicidade , Células A549 , Células Epiteliais Alveolares/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Citocinas/metabolismo , Humanos , Inflamação/induzido quimicamente , Inflamação/metabolismo , Pulmão , Proteína A Associada a Surfactante Pulmonar/metabolismo , Espécies Reativas de Oxigênio/metabolismoRESUMO
Acacia farnesiana pods are rich in secondary metabolites and their biological activities have been recorded as antibacterial, antioxidant and anthelmintic. Previously, an in vitro bioguided study showed the important ovicidal and larvicidal effects of an organic fraction (EtOAc-F) from a hydroalcoholic extract of A. farnesiana pods against Haemonchus contortus. The present study aimed to assess the in vivo anthelmintic effect of EtOAc-F from A. farnesiana pods on the H. contortus faecal egg elimination in female lambs and on the infective larvae (L3) population reduction in coprocultures. The EtOAc-F was obtained from a hydroalcoholic extract from A. farnesiana pods through chromatographic procedures; additionally, some secondary compounds were identified using high-performance liquid chromatography (HPLC). Twenty-one 'Katahdin' crossbred female lambs ranging from three to four months of age, with body weights 21.9 ± 0.39 kg were used. Animals were orally infected with H. contortus (L3) by a single dose of 350 L3/kg BW. Three experimental groups (n = 7) were assigned as follows: 1) Control (untreated), 2) Albendazole, as a positive control (at 7.5 mg/kg BW, unique dose) and 3) EtOAc-F (at 100 mg/kg BW, once every third day, with three applications in total). Individual faecal samples were collected once a week for 5 weeks (at days 38, 45, 52, 59 and 66) post-treatment, to measure the faecal egg counts (FEC) and to obtain the H. contortus (L3) population from faecal cultures. The highest FEC reduction caused by EtOAc-F was 67.7%; meanwhile, albendazole showed a total FEC reduction after the second week post-treatment (day 45). On the other hand, the fraction caused an important reduction in the larval population in coprocultures (54.3-68.5%). The phytochemical analysis revealed the presence of galloyl derivatives and flavonoids as major compounds. The A. farnesiana pods could serve as a natural anthelmintic for the control of H. contortus, and perhaps for controlling other parasites of veterinary importance.
Assuntos
Acacia/química , Anti-Helmínticos/uso terapêutico , Hemoncose/veterinária , Extratos Vegetais/uso terapêutico , Doenças dos Ovinos/tratamento farmacológico , Animais , Anti-Helmínticos/isolamento & purificação , Anti-Helmínticos/farmacologia , Fezes/parasitologia , Feminino , Flavonoides/química , Ácido Gálico/química , Hemoncose/tratamento farmacológico , Hemoncose/parasitologia , Haemonchus/efeitos dos fármacos , Haemonchus/isolamento & purificação , Hematócrito/veterinária , Contagem de Ovos de Parasitas/veterinária , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Distribuição Aleatória , Ovinos , Doenças dos Ovinos/parasitologiaRESUMO
INTRODUCTION: Malignant gastric outlet obstruction is a condition that alters patient quality of life, conditioning progressive malnutrition. However, self-expanding metal stents (SEMSs) and surgical gastrojejunostomy (SGJ) are palliative options in patients with unresectable disease. AIMS: To characterize patients diagnosed with malignant gastric outlet obstruction requiring SEMS placement or SGJ. MATERIALS AND METHODS: Sequential non-probability convenience sampling was conducted and included 68 patients, 40 of whom had SEMS placement and 28 of whom underwent SGJ. RESULTS: Patients sought medical consultations for the symptoms of vomiting, abdominal pain, weight loss, and upper gastrointestinal bleeding. Ninety-five percent of the patients in the SEMS group and 64.3% in the SGJ group presented with metastasis. Technical and clinical success, patency duration, and number of patients with no complications were greater in the SGJ group. Mean survival in days was 88 (SD ± 21) in the SEMS group versus 501 (SD ± 122) in the SGJ group. The log-rank test detected a statistically significant difference between subgroups (p = 0.00). CONCLUSION: SGJ has greater technical and clinical success rates but SEMS placement continues to be utilized in distal gastric cancer, especially in cases in which surgery is not an option.
RESUMO
OBJECTIVE: To evaluate the feasibility of using the Sentinella® portable gamma-camera for the diagnosis of brain death (BD). DESIGN: A prospective, observational feasibility study was carried out. SETTING: Intensive Care Unit of a third level hospital. PATIENTS: Consecutive recording was made of the adults diagnosed with brain death based on clinical criteria following admission to the Intensive Care Unit in the period from January to December 2017. INTERVENTIONS: The procedure was performed at the patient bedside with the intravenous administration of technetium 99 metastable hexamethylpropylene amine oxime. The absence of perfusion in the cerebral hemispheres and brainstem was described as a pattern consistent with BD. The diagnosis was correlated to the transcranial Doppler and / or electroencephalographic findings. RESULTS: A total of 66.1% of the patients were men with an average age of 60 years [IQR: 51-72]. The most frequent causes resulting in BD were hemorrhagic stroke (48.2%, n=27), followed by traumatic brain injury (30.4%, n=17), ischemic stroke (10.7%, n=6) and post-cardiac arrest anoxic encephalopathy (7.1%, n=4). A clinical diagnosis of BD was made in all cases, and the portable gamma-camera confirmed the diagnosis in 100% of the patients with a pattern characterized by the absence of brain perfusion. In addition, the results were compared with the transcranial Doppler findings in 46 patients, confirming the presence of diastolic reverberation and / or systolic peaks. The electroencephalographic tracing was obtained in 10 cases, with the appearance of electrical silence, due to the absence of an acoustic window in the transcranial Doppler study. CONCLUSIONS: A portable gamma-camera could be a useful and feasible tool for the diagnosis of BD.
Assuntos
Morte Encefálica/diagnóstico por imagem , Câmaras gama , Cintilografia , Idoso , Lesões Encefálicas Traumáticas/complicações , Lesões Encefálicas Traumáticas/diagnóstico por imagem , Eletroencefalografia , Estudos de Viabilidade , Feminino , Acidente Vascular Cerebral Hemorrágico/complicações , Acidente Vascular Cerebral Hemorrágico/diagnóstico por imagem , Humanos , AVC Isquêmico/complicações , AVC Isquêmico/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Oximas/administração & dosagem , Síndrome Pós-Parada Cardíaca/complicações , Síndrome Pós-Parada Cardíaca/diagnóstico por imagem , Estudos Prospectivos , Cintilografia/instrumentação , Cintilografia/métodos , Tecnécio/administração & dosagem , Ultrassonografia Doppler TranscranianaRESUMO
ETHNOPHARMACOLOGY RELEVANCE: Acacia farnesiana (L.) Willd is a shrub legume used as condiment, medicinal plant and bioactive herbage. This species is used in traditional medicine of several countries to relieve the symptoms of gastrointestinal diseases, diarrhoea, stomach pain and typhoid as well as astringent, antidysenteric and anthelmintic. Some studies have shown that this plant displayed anthelmintic activity against several gastrointestinal nematode parasites of livestock, and also against parasites of human beings, such as malaria. AIM OF THE STUDY: This work describes the isolation and chemical identification of the anthelmintic compounds of Acacia farnesiana pods against eggs and infective larvae of the sheep parasitic nematode Haemonchus contortus. The bio-guided chemical fractioning of A. farnesiana pods using ethyl acetate against H. contortus eggs and infective larvae allowed for the identification of naringenin 7-O-(6â³-galloylglucoside) (flavonol group) as the compound responsible for the anthelmintic activity against this important parasitic nematode. MATERIALS AND METHODS: Anthelmintic activity was assessed using the egg hatching inhibition assay (EHI) and mortality tests. A complete hydroalcoholic extract (HA-E) at 12.5-50 mg/mL, an aqueous fraction (Aq-F) at 3.12-25 mg/mL and an ethyl acetate fraction (EtOAc-F) at 3.12-25 mg/mL were analysed in the first selection phase. The purification of compounds through the chromatographic separation of the organic fraction resulted in nine less complex mixtures (C1F1, C1F2, C1F3, C1F4, C2F1, C2F2, C2F3, C2F4 and C2F5) that were assessed at 0.62-5 mg/mL concentrations. In addition, thiabendazole (0.6 mg/mL) and ivermectin (5 mg/mL) were used as positive controls. Likewise, distilled water and 4% methanol were used as negative controls. The bioactive compounds of EtOAc-F were obtained and characterised through chromatographic processes like open column chromatography, thin layer chromatography (TLC), high performance liquid chromatography (HPLC), ultra-performance liquid chromatography (UPLC) and gass chromatography-mass detection (GC-MS). Bioactive compounds were identified by spectroscopy (1H and 13C NMR) and mass spectrometric analysis. Additionally, the H. contortus eggs and infective larvae exposed to the bioactive compounds were observed through environmental scanning electron microscopy (ESEM) and confocal laser scanning microscopy (CLSM). Data were analysed based on a completely randomised design using ANOVA through a general linear model. RESULTS: The EtOAc-F fraction showed the highest ovicidal and larvicidal activities, at close to 100% at 3.12 and 6.25 mg/mL, respectively. The treatments C1F2, C1F3 and C2F3 displayed the main ovicidal activity (80-100%) at 2.5 mg/mL. The major compounds found in these sub-fractions were identified as galloyl derivatives and flavanones, including gallic acid (1), methyl gallate (2), ethyl gallate (3), naringin (4), naringenin 7-O-(4â³, 6â³-digalloylglucoside) (5), naringenin 7-O-(6â³-galloylglucoside) (6) and naringenin (7). Likewise, the ESEM and CLSM images showed that the assessed compounds adhered to the eggshell and the external cuticle of the larvae. CONCLUSION: These results indicate that A. farnesiana pods contain nematocidal compounds and might be promising natural anthelmintic agents against H. contortus. This leguminous plant could be used as a nutraceutical food source for the control of gastrointestinal nematodes in small ruminants.
Assuntos
Acacia/química , Antinematódeos/farmacologia , Hemoncose/tratamento farmacológico , Haemonchus/efeitos dos fármacos , Extratos Vegetais/farmacologia , Animais , Antinematódeos/isolamento & purificação , Antinematódeos/uso terapêutico , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Flavonoides/uso terapêutico , Hemoncose/parasitologia , Hemoncose/veterinária , Larva/efeitos dos fármacos , Óvulo/efeitos dos fármacos , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/uso terapêutico , Ovinos/parasitologiaRESUMO
This work is focused on the study of the dynamic surface properties of spread monolayers of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), which is the main component of the pulmonary surfactant (PS), in the region of high surface pressures and at different temperatures. The increase of temperature from 25 to 35⯰C led to a decrease of surface elasticity in the high surface pressure range corresponding to physiological conditions inside alveoli during breathing. Furthermore, the obtained results evidenced that the relaxation processes in spread DPPC monolayer were accelerated with the increase of temperature, which resulted in two different effects. On one hand, it led to the increase of hysteresis of surface pressure isotherms, which was an important condition for maximizing air penetration into alveoli; whereas on the other hand, it prevented reaching extremely high surface pressure, which could result in a premature alveolar collapse.
Assuntos
1,2-Dipalmitoilfosfatidilcolina/química , Termodinâmica , Elasticidade , Tamanho da Partícula , Pressão , Propriedades de SuperfícieRESUMO
We report two cases of hemoglobin Sendagi in a Romanian family residing in Spain: a four-year-old boy and his mother, who had been previously diagnosed with another type of congenital hemolytic anemia and had undergone splenectomy in her country during childhood. The unstable hemoglobin variant, hemoglobin Sendagi, is characterized by decreased oxygen affinity caused by replacement of one of the critical amino acid residues, phenylalanine beta 42 (CD1) of the beta-chain, with valine in the heme pocket, resulting in methemoglobin formation. As a result of migratory movements in Europe, new disease-causing hemoglobin variants are emerging in our country. Here, capillary electrophoresis enabled the identification of the variant and a molecular study was used to establish an accurate diagnosis.
Assuntos
Eletroforese Capilar/métodos , Hemoglobinas Anormais/metabolismo , Mutação , Adulto , Pré-Escolar , Feminino , Humanos , MasculinoRESUMO
We propose a minimalist stochastic population model of maize, focused on the description of the maize vegetative stages (seedlings with different number of leaves) involved in the propagation of vector-borne diseases. This model was parameterized from laboratory and field experiments and from observational field studies for multiple hybrids and different weather and soil conditions, taking into account only temperature as input variable. We propose three different submodels to estimate the distribution of the Final Leaf Number NFLN in the plants and to estimate the tassel initiation probability. The first submodel (submodel A), with a fixed NFLN, is adaptable to any particular hybrid, the second and third submodels allow to simulate plants with an empirical NFLN distribution according to bibliographic averages (submodel B) or according to a Poisson Process (submodel C). The three submodels are able to describe the temporal development of populations and events. A good agreement is observed between the development times predicted by the model and the values obtained from laboratory experiments at constant temperature, field experiments carried out in Brazil and Australia and observational studies performed in Argentina. This model may be improved and coupled to leaf growth models and leaf area estimation models to be able to estimate not only the temporal development of populations and events but also the temporal development of the leaf area by plant, which is believed to be related to the carrying capacity of maize specialists insects, vectors of maize diseases.
Assuntos
Modelos Biológicos , Fotoperíodo , Folhas de Planta , Doenças Transmitidas por Vetores , Zea mays , Processos EstocásticosRESUMO
Gastrointestinal nematodes (GIN) are responsible for enormous economic losses worldwide. The use of anthelmintic drugs reduces the parasitic burden in ruminants. However, the excessive use of these drugs triggers anthelmintic resistance in these parasites, which leads to a worrisome inefficacy of most of the commercially available antiparasitic drugs. Caesalpinia coriaria is an arboreal legume possessing medical properties, although the antiparasitic potential of this plant against animal parasitic nematodes has not yet been studied. The aim of this study was to assess the in vitro ovicidal activity of a hydro-alcoholic extract (HA-E) from C. coriaria fruits against GIN and to identify the compounds responsible for this activity through an egg hatch inhibition (EHI) assay. GIN eggs obtained from cattle faeces were used in bio-guided assays. The HA-E was subjected to a liquid-liquid extraction using water and ethyl acetate to obtain two fractions, an organic fraction (EtOAc-F, 27% yield) and an aqueous (Aq-F, 73% yield) fraction. The chromatographic fractionation of the EtOAc-F (2 gr) was performed on a glass column packed with silica gel and eluted with dichloromethane/methanol with 10% ascending polarity. The bioactive compounds were analysed using high-performance liquid chromatography (HPLC) with UV detection, nuclear magnetic resonance (NMR) spectroscopy and mass spectroscopy (MS). The HA-E extract and the EtOAc-F showed ovicidal activity at a LC50 of 0.92 and 0.16â¯mg/mL, respectively. A concentration-dependant effect was observed in both treatments. Chromatographic fractionation of the EtOAc-F, allowed for the isolation and characterisation of three important compounds: methyl gallate (1), gallic acid (2) and an unidentified compound (UC). The bioactive molecules (2 and UC) displayed an ovicidal activity close to 100% at 1â¯mg/mL concentration. The results of this work show that gallic acid (2) isolated from C. coriaria fruits is responsible for its ovicidal activity. The use of Caesalpinia coriaria could be explored in future studies as an environmentally-friendly alternative for the control of GIN in ruminants.