RESUMO
This chapter introduces protocols for culturing and maintaining Dictyostelium discoideum and methods for conducting virulence assays in this organism to study bacterial pathogenicity. It outlines advanced techniques, such as automated microscopy and flow cytometry, for detailed cellular analysis and traditional microbiological approaches. These comprehensive protocols will enable researchers to probe the virulence factors of pathogens like Klebsiella pneumoniae and to elucidate the details of host-pathogen interactions within a cost-effective and adaptable laboratory framework.
Assuntos
Dictyostelium , Citometria de Fluxo , Klebsiella pneumoniae , Dictyostelium/microbiologia , Citometria de Fluxo/métodos , Klebsiella pneumoniae/patogenicidade , Fagocitose , Virulência , Interações Hospedeiro-Patógeno , Microscopia/métodosRESUMO
PURPOSE: Maximal-safe resection has been shown to improve overall survival in elderly patients with glioblastoma in observational studies, however, the only clinical trial comparing resection versus biopsy in elderly patients with surgically-accessible glioblastoma showed no improvements in overall survival. A meta-analysis is needed to assess whether surgical resection of glioblastoma in older patients improves surgical outcomes when compared to biopsy alone. METHODS: A search was conducted until October 9th, 2023, to identify published studies reporting the clinical outcomes of glioblastoma patients > 65 years undergoing resection or biopsy (PubMed, MEDLINE, EMBASE, and COCHRANE). Primary outcomes were overall survival (OS), progression-free survival (PFS), and complications. We analyzed mean difference (MD) and hazard ratio (HR) for survival outcomes. Postoperative complications were analyzed as a dichotomic categorical variable with risk ratio (RR). RESULTS: From 784 articles, 20 cohort studies and 1 randomized controlled trial met our inclusion criteria, considering 20,523 patients for analysis. Patients undergoing surgical resection had an overall survival MD of 6.13 months (CI 95%=2.43-9.82, p = < 0.001) with a HR of 0.43 (95% CI = 0.35-0.52, p = < 0.00001). The progression-free survival MD was 2.34 months (95%CI = 0.79-3.89, p = 0.003) with a 0.50 h favoring resection (95%CI = 0.37-0.68, p = < 0.00001). The complication RR was higher in the resection group favoring biopsy (1.49, 95%CI = 1.06-2.10). CONCLUSIONS: Our meta-analysis suggests that upfront resection is associated with improved overall survival and progression-free survival in elderly patients with newly diagnosed glioblastoma over biopsy. However, postoperative complications are more common with resection. Future clinical trials are essential to provide more robust evaluation in this challenging patient population.
Assuntos
Neoplasias Encefálicas , Glioblastoma , Procedimentos Neurocirúrgicos , Humanos , Glioblastoma/cirurgia , Glioblastoma/patologia , Glioblastoma/mortalidade , Neoplasias Encefálicas/cirurgia , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/mortalidade , Prognóstico , Idoso , Biópsia , Procedimentos Neurocirúrgicos/métodosRESUMO
The rise of antibiotic-resistant bacterial strains represents an important challenge for global health, underscoring the critical need for innovative strategies to confront this threat. Natural products and their derivatives have emerged as a promising reservoir for drug discovery. The social amoeba Dictyostelium discoideum is a potent model organism in this effort. Employing this invertebrate model, we introduce a novel perspective to investigate natural plant extracts in search of molecules with potential antivirulence activity. Our work established an easy-scalable developmental assay targeting a virulent strain of Klebsiella pneumoniae, with Helenium aromaticum as the representative plant. The main objective was to identify tentative compounds from the Helenium aromaticum extract that attenuate the virulence of K. pneumoniae virulence without inducing cytotoxic effects on amoeba cells. Notably, the methanolic root extract of H. aromaticum fulfilled these prerequisites compared to the dichloromethane extract. Using UHPLC Q/Orbitrap/ESI/MS/MS, 63 compounds were tentatively identified in both extracts, 47 in the methanolic and 29 in the dichloromethane, with 13 compounds in common. This research underscores the potential of employing D. discoideum-assisted pharmacognosy to discover new antivirulence agents against multidrug-resistant pathogens.
RESUMO
Inflammation and mucus production are prevalent characteristics of chronic respiratory conditions, such as asthma and chronic chronic obstructive pulmonary disease (COPD). Biological co-factors, including bacteria, viruses, and fungi, may exacerbate these diseases by activating various pathways associated with airway diseases. An example is the fungus Pneumocystis, which is linked to severe COPD in human patients. Recent evidence has demonstrated that Pneumocystis significantly enhanced inflammation and mucus hypersecretion in a rat model of elastase-induced COPD. The present study specifically aims to investigate two additional aspects associated with the pathology induced by Pneumocystis infection: inflammation and collagen deposition around airways. To this end, the focus was to investigate the role of the IL-1ß pro-inflammatory pathway during Pneumocystis infection in COPD rats. Several airway pathology-related features, such as inflammation, mucus hypersecretion, and fibrosis, were evaluated using histological and molecular techniques. COPD animals infected with Pneumocystis exhibited elevated inflammation levels, including a synergistic increase in IL-1ß and Cox-2. Furthermore, protein levels of the IL-1ß-dependent transcription factor cAMP response element-binding (CREB) showed a synergistic elevation of their phosphorylated version in the lungs of COPD animals infected with Pneumocystis, while mucus levels were notably higher in the airways of COPD-infected animals. Interestingly, a CREB responsive element (CRE) was identified in the Muc5b promoter. The presence of CREB in the Muc5b promoter was synergistically increased in COPD animals infected with Pneumocystis compared to other experimental groups. Finally, an increment of deposited collagen was identified surrounding the airways of COPD animals infected with Pneumocystis compared with the other experimental animal groups and correlated with the increase of Tgfß1 mRNA levels. These findings emphasize the role of Pneumocystis as a potential biological co-factor in chronic respiratory diseases like COPD or asthma, warranting new perspectives in the treatment of chronic respiratory diseases.
Assuntos
Asma , Pneumocystis , Pneumonia por Pneumocystis , Doença Pulmonar Obstrutiva Crônica , Humanos , Ratos , Animais , Elastase Pancreática/metabolismo , Doença Pulmonar Obstrutiva Crônica/metabolismo , Pulmão/patologia , Asma/metabolismo , Muco/metabolismo , Inflamação/metabolismo , Colágeno/metabolismoRESUMO
The emergence of hypervirulent Klebsiella pneumoniae (hvKP) strains poses a significant threat to public health due to high mortality rates and propensity to cause severe community-acquired infections in healthy individuals. The ability to form biofilms and produce a protective capsule contributes to its enhanced virulence and is a significant challenge to effective antibiotic treatment. Polyphosphate kinase 1 (PPK1) is an enzyme responsible for inorganic polyphosphate synthesis and plays a vital role in regulating various physiological processes in bacteria. In this study, we investigated the impact of polyP metabolism on the biofilm and capsule formation and virulence traits in hvKP using Dictyostelium discoideum amoeba as a model host. We found that the PPK1 null mutant was impaired in biofilm and capsule formation and showed attenuated virulence in D. discoideum compared to the wild-type strain. We performed a proteomic analysis to gain further insights into the underlying molecular mechanism. The results revealed that the PPK1 mutant had a differential expression of proteins involved in capsule synthesis (Wzi-Ugd), biofilm formation (MrkC-D-H), synthesis of the colibactin genotoxin precursor (ClbB), as well as proteins associated with the synthesis and modification of lipid A (ArnB-LpxC-PagP). These proteomic findings corroborate the phenotypic observations and indicate that the PPK1 mutation is associated with impaired biofilm and capsule formation and attenuated virulence in hvKP. Overall, our study highlights the importance of polyP synthesis in regulating extracellular biomolecules and virulence in K. pneumoniae and provides insights into potential therapeutic targets for treating K. pneumoniae infections.
Assuntos
Dictyostelium , Klebsiella pneumoniae , Humanos , Virulência , Klebsiella pneumoniae/genética , Polifosfatos , Proteômica , BiofilmesRESUMO
MicroRNAs are an emerging class of synaptic regulators. These small noncoding RNAs post-transcriptionally regulate gene expression, thereby altering neuronal pathways and shaping cell-to-cell communication. Their ability to rapidly alter gene expression and target multiple pathways makes them interesting candidates in the study of synaptic plasticity. Here, we demonstrate that the proconvulsive microRNA miR-324-5p regulates excitatory synapse structure and function in the hippocampus of mice. Both Mir324 knockout (KO) and miR-324-5p antagomir treatment significantly reduce dendritic spine density in the hippocampal CA1 subregion, and Mir324 KO, but not miR-324-5p antagomir treatment, shift dendritic spine morphology, reducing the proportion of thin, "unstable" spines. Western blot and quantitative Real-Time PCR revealed changes in protein and mRNA levels for potassium channels, cytoskeletal components, and synaptic markers, including MAP2 and Kv4.2, which are important for long-term potentiation (LTP). In line with these findings, slice electrophysiology revealed that LTP is severely impaired in Mir324 KO mice, while neurotransmitter release probability remains unchanged. Overall, this study demonstrates that miR-324-5p regulates dendritic spine density, morphology, and plasticity in the hippocampus, potentially via multiple cytoskeletal and synaptic modulators.
Assuntos
Potenciação de Longa Duração , MicroRNAs , Camundongos , Animais , Potenciação de Longa Duração/fisiologia , Espinhas Dendríticas/metabolismo , Antagomirs/metabolismo , Hipocampo/metabolismo , Plasticidade Neuronal/genética , Sinapses/metabolismo , Camundongos Knockout , MicroRNAs/genética , MicroRNAs/metabolismoRESUMO
This paper evaluates how the July 2005 London terrorist attacks affected Muslim teenagers' education plans and decisions. The attacks triggered a violent backslash against the Muslim community, which could have affected their incentives to continue in full-time education. I examine panel data on educational attitudes from the "Next Steps" Survey in England and use the month the survey was administered to divide individuals into treatment and control groups. I find that the attacks negatively affected the education plans of Muslims, but not those of any other major religious group. The probability of planning to continue in non-compulsory full-time education decreased by around 4.4% points for Muslims after the attacks. This corresponds to a 69% increase in individuals who were not sure whether to continue or drop out of full-time education. However, this change in plans appears to be a temporary reaction, since it did not affect students' actual decisions two years later.
RESUMO
Potato cyst nematodes (PCNs; Globodera spp.) cause significant losses in worldwide cultivated potato (Solanum tuberosum) crops. In Colombia, PCN was first reported in 1970 (Baeza 1972), although this report lacked a comprehensive species description and diagnosis. After that, G. pallida has been the only PCN species reported affecting potatoes in the main producing regions of Colombia (Evans et al. 1975; Nieto et al. 1983; Vallejo et al. 2021). However, in the survey conducted by Vallejo et al. (2021), a single sample from Chocontá, Cundinamarca in the central region of the country (N 5,22396046668291, W -73,6571338400244) showed molecular characters similar to G. rostochiensis. As correct identification is essential for effective pest management, the location was re-sampled in September 2022. From the soil samples collected, PCN cysts and second-stage juveniles (J2s) were retrieved from soil using Fenwick and centrifugation methods, respectively. Morphometric characters of cysts (n = 53) were consistent with G. rostochiensis, with a length without neck (L) ranging from 451 to 614 µm (XÌ = 546.9 ± 20.3 µm), width (W) from 424 to 658 µm (XÌ = 546.9 ± 25.5 µm) and L/W ratio was 1.00 ± 0.02. Distance from anus to vulva varied from 41 to 109 µm (XÌ =75.67 ± 13.8 µm), Granek's ratio from 2.3 to 5.5 µm (XÌ = 3.89 ± 0.7 µm), and the number of cuticular ridges between the vulva and the anus were 14 to 20 (XÌ = 16.19 ± 1.7). The second-stage juvenile (n = 90) length ranged from 394 to 547 µm (XÌ = 495.62 ± 31.0 µm), the stylet length varied from 18 to 24 µm (XÌ = 21.21 ± 0.9 µm) with rounded knobs. The length of the hyaline tail ranged from 20 - 31 µm (XÌ = 24.09 ± 1.92) and the true tail from 31- 56 µm (XÌ = 48.30 ± 5.71 µm). Molecular analyses confirmed morphological identification. DNA was extracted from cysts and J2s. PCR was performed for the 28S rDNA D2-D3 segment using primers D2A and D3B (Subbotin et al. 2006), and for the mitochondrial COI gene region using primers JB3 and JB5 (Derycke et al. 2005). BLAST analyses of target 28S rDNA D2-D3 sequences (OP293373-OP293380) showed 100% identity of the 658 bp to other sequences on Genbank, including isolates from Turkey, United Kingdom, and Iran (MK311329.1, MG994942.1, KU297659.1, and KU297658.1). Similarly, the target COI region sequences (OP297993-OP298001) were 100% identical to the 407 bp of G. rostochiensis POT01 isolate from Germany, and 99.75% identical to voucher NRM67 from Indonesia, and isolate CD2200 from USA (MF773722.1, MT240262.1, and MN095979.1). Phylogenetic analysis of both gene regions strongly supported G. rostochiensis, with the Colombian sequences clustering with MH399815.1, and KU297654.1 isolates for the COI and 28S regions, respectively (Fig. 1S). In addition, a pathogenicity test was conducted in the greenhouse. For this, ten cysts were inoculated to potato plants of Criolla variety grown in 5 pots of 15 cm diameter with sterile soil and sand (1:1). Noninoculated plants served as controls (three replicates each). After three months, 54 ± 23 cysts/100 g of soil were isolated from inoculated plants (Fig. 2S), resulting in a reproduction factor (R=Pf/Pi) of 4.54 ± 0.86, while no yellow females or cysts were observed on the control plants. To our knowledge, this is the first report of G. rostochiensis in Colombia. This is an important pest that causes serious yield losses of potatoes and is a quarantine nematode in many countries (EPPO 2017). Further studies are necessary to prevent the spread of this PCN species in the main producing potato regions of Colombia.
RESUMO
Age-related loss of skeletal muscle mass leads to a reduction of strength. It is likely due to an inadequate stimulation of muscle protein synthesis (MPS) in response to anabolic stimuli, such as mechanical load. Ribosome biogenesis is a major determinant of translational capacity and is essential for the control of muscle mass. This mini-review aims to put forth the hypothesis that ribosome biogenesis is impaired by aging in response to mechanical load, which could contribute to the age-related anabolic resistance and progressive muscle atrophy. Recent animal studies indicate that aging impedes muscle hypertrophic response to mechanical overload. This is associated with an impaired transcription of ribosomal DNA (rDNA) by RNA polymerase I (Pol I), a limited increase in total RNA concentration, a blunted activation of AKT/mTOR pathway, and an increased phosphorylation of AMPK. In contrast, an age-mediated impairment of ribosome biogenesis is unlikely in response to electrical stimulations. In human, the hypertrophic response to resistance exercise training is diminished with age. This is accompanied by a deficit in long-term MPS and an absence of increased total RNA concentration. The results addressing the acute response to resistance exercise suggest an impaired Pol I-mediated rDNA transcription and attenuated activation/expression of several upstream regulators of ribosome biogenesis in muscles from aged individuals. Altogether, emerging evidence indicates that impaired ribosome biogenesis could partly explain age-related anabolic resistance to mechanical load, which may ultimately contribute to progressive muscle atrophy. Future research should develop more advanced molecular tools to provide in-depth analysis of muscle ribosome biogenesis.
RESUMO
Photoplethysmography (PPG) signals have been widely used in evaluating cardiovascular biomarkers, however, there is a lack of in-depth understanding of the remote usage of this technology and its viability for underdeveloped countries. This study aims to quantitatively evaluate the performance of a low-cost wireless PPG device in detecting ultra-short-term time-domain pulse rate variability (PRV) parameters in different postures and breathing patterns. A total of 30 healthy subjects were recruited. ECG and PPG signals were simultaneously recorded in 3 min using miniaturized wearable sensors. Four heart rate variability (HRV) and PRV parameters were extracted from ECG and PPG signals, respectively, and compared using analysis of variance (ANOVA) or Scheirer-Ray-Hare test with post hoc analysis. In addition, the data loss was calculated as the percentage of missing sampling points. Posture did not present statistical differences across the PRV parameters but a statistical difference between indicators was found. Strong variation was found for the RMSSD indicator in the standing posture. The sitting position in both breathing patterns demonstrated the lowest data loss (1.0 ± 0.6 and 1.0 ± 0.7) and the lowest percentage of different factors for all indicators. The usage of commercial PPG and BLE devices can allow the reliable extraction of the PPG signal and PRV indicators in real time.
Assuntos
Fotopletismografia , Postura , Humanos , Frequência Cardíaca/fisiologia , Voluntários Saudáveis , Respiração , EletrocardiografiaRESUMO
Inflammation and mucus hypersecretion are frequent pathology features of chronic respiratory diseases such as asthma and COPD. Selected bacteria, viruses and fungi may synergize as co-factors in aggravating disease by activating pathways that are able to induce airway pathology. Pneumocystis infection induces inflammation and mucus hypersecretion in immune competent and compromised humans and animals. This fungus is a frequent colonizer in patients with COPD. Therefore, it becomes essential to identify whether it has a role in aggravating COPD severity. This work used an elastase-induced COPD model to evaluate the role of Pneumocystis in the exacerbation of pathology, including COPD-like lung lesions, inflammation and mucus hypersecretion. Animals infected with Pneumocystis developed increased histology features of COPD, inflammatory cuffs around airways and lung vasculature plus mucus hypersecretion. Pneumocystis induced a synergic increment in levels of inflammation markers (Cxcl2, IL6, IL8 and IL10) and mucins (Muc5ac/Muc5b). Levels of STAT6-dependent transcription factors Gata3, FoxA3 and Spdef were also synergically increased in Pneumocystis infected animals and elastase-induced COPD, while the levels of the mucous cell-hyperplasia transcription factor FoxA2 were decreased compared to the other groups. Results document that Pneumocystis is a co-factor for disease severity in this elastase-induced-COPD model and highlight the relevance of STAT6 pathway in Pneumocystis pathogenesis.
RESUMO
Duddingtonia flagrans is a nematophagous fungus employed as a biocontrol agent of gastrointestinal nematodes in ruminants. After oral ingestion and passage through the digestive tract of animals, this microorganism captures the nematodes in the feces. The drastic conditions of ruminant digestive tract could affect fungi chlamydospores and therefore biocontrol activity. The aim of this study was to evaluate in vitro the effect of four ruminant digestive segments on the concentration and nematode predatory ability of a Colombian native strain of D. flagrans. The sequential four-step methodology proposed evaluated conditions of the oral cavity, rumen, abomasum, and small intestine such as pH (2, 6, 8), enzymes (pepsin, pancreatin), temperature (39 °C), and anaerobiosis comparing short (7 h) and long (51 h) exposure times. The results showed that the nematode predatory ability of the fungi is affected by sequential exposure to gastrointestinal segments and this effect depends on the exposure time to those conditions. After short exposure (7 h) through the four ruminant digestive segments, the fungi had a nematode predatory ability of 62%, in contrast, after long exposure (51 h) the nematode predatory ability was lost (0%). Moreover, the number of broken chlamydospores was higher in the long-exposure assay.
Assuntos
Ascomicetos , Duddingtonia , Nematoides , Animais , Ovinos , Larva , Trato Gastrointestinal/microbiologia , Fezes , Carneiro Doméstico , Boca , Controle Biológico de Vetores/métodosRESUMO
PURPOSE: Internal carotid artery (ICA) aneurysm treatment with a flow diverter (FD) has shown an adequate efficacy and safety profile, presenting high complete occlusion or near occlusion rates with low complications during follow-up. The purpose of this study was to evaluate the efficacy and safety of FD treatment in non-ruptured internal carotid aneurysms. MATERIALS AND METHODS: This is a retrospective, single-center, observational study evaluating patients diagnosed with unruptured ICA aneurysms treated with an FD between January 1, 2014, and January 1, 2020. We analyzed an anonymized database. The primary effectiveness endpoint was complete occlusion (O'Kelly-Marotta D, OKM-D) of the target aneurysm through 1-year follow-up. The safety endpoint was the evaluation of modified Rankin Scale (mRS) 90 days after treatment, considering a favorable outcome an mRS 0-2. RESULTS: A total of 106 patients were treated with an FD, 91.5% were women; the mean follow- up was 427.2±144.8 days. Technical success was achieved in 105 cases (99.1%). All patients included had 1-year follow-up digital subtraction angiography control; 78 patients (73.6%) completed the primary efficacy endpoint by achieving total occlusion (OKM-D). Giant aneurysms had a higher risk of not achieving complete occlusion (risk ratio, 3.07; 95% confidence interval, 1.70 - 5.54]). The safety endpoint of mRS 0-2 at 90 days was accomplished in 103 patients (97.2%). CONCLUSION: Treatment of unruptured ICA aneurysms with an FD showed high 1-year total occlusion results, with very low morbidity and mortality complications.
RESUMO
The primary mechanism for neuron death after an ischemic stroke is excitotoxic injury. Excessive depolarization leads to NMDA-mediated calcium entry to the neuron and, subsequently, cellular death. Therefore, the inhibition of the NMDA channel has been proposed as a neuroprotective measure in ischemic stroke. The high morbimortality associated with stroke warrants new therapies that can improve the functional prognosis of patients. Memantine is a non-competitive NMDA receptor antagonist which has gained attention as a potential drug for ischemic stroke. Here we analyze the available preclinical and clinical evidence concerning the use of memantine following an ischemic stroke. Preclinical evidence shows inhibition of the excitotoxic cascade, as well as improved outcomes in terms of motor and sensory function with the use of memantine. The available clinical trials of high-dose memantine in patients poststroke have found that it can improve patients' NIHSS and Barthel index and help patients with poststroke aphasia and intracranial hemorrhage. These results suggest that memantine has a clinically relevant neuroprotective effect; however, small sample sizes and other study shortcomings limit the impact of these findings. Even so, current studies show promising results that should serve as a basis to promote future research to conclusively determine if memantine does improve the outcomes of patients' post-ischemic stroke. We anticipate that future trials will fill current gaps in knowledge, and these latter results will broaden the therapeutic arsenal for clinicians looking to improve the prognosis of patients poststroke.
RESUMO
Resumen Introducción La intervención de terapia ocupacional con personas mayores en procesos de fin de vida en contextos hospitalarios presenta escasa documentación científica en Chile. Dado el aumento de la población mayor, la alta prevalencia de enfermedades crónicas en ella y las tasas de mortalidad hospitalaria, se identifica la necesidad de revisar las intervenciones que se realizan en los procesos de fin de vida de las personas mayores. Objetivo Caracterizar intervenciones de terapia ocupacional con personas mayores que cursan su proceso de fin de vida, desde la percepción de terapeutas ocupacionales dedicados/as al área, en contextos hospitalarios públicos de Chile. Método La investigación es de tipo cualitativa enmarcada dentro del paradigma constructivista bajo el enfoque fenomenológico, utilizando como técnica de recolección de información la entrevista semiestructurada y posterior análisis de contenido. La muestra de estudio está compuesta por terapeutas ocupacionales que ejercen su labor en hospitales públicos del país. Resultados Se identifica a terapeutas ocupacionales como agentes que otorgan cuidados humanizantes y acompañamiento durante las intervenciones en procesos de fin de vida, y a las familias como un facilitador del mismo. Se releva una visión integral de la persona en estos procesos. Conclusiones Existe consenso en el enfoque e intervenciones de terapia ocupacional identificadas por las/os participantes, y resulta similar a lo descrito en la literatura internacional. Faltan lineamientos de política pública local que permitan definir de mejor manera el rol profesional en este contexto.
Resumo Introdução A intervenção da terapia ocupacional com idosos nos processos de fim de vida em contextos hospitalares apresenta pouca documentação científica no Chile. Diante do aumento da população idosa, da alta prevalência de doenças crônicas nesta população e das taxas de mortalidade hospitalar, identifica-se a necessidade de rever as intervenções realizadas nos processos de fim de vida do idoso. Objetivo Caracterizar as intervenções de terapia ocupacional com idosos em processo de fim de vida, a partir da percepção de terapeutas ocupacionais da área, em contextos hospitalares públicos no Chile. Método A pesquisa é do tipo qualitativo na perspectiva do paradigma construtivista sob a abordagem fenomenológica, utilizando-se de entrevista semiestruturada como técnica de coleta de informações e posterior análise de conteúdo. A amostra do estudo é composta por terapeutas ocupacionais que atuam em hospitais públicos no Chile. Resultados Os terapeutas ocupacionais são identificados como agentes que prestam atendimento humanizado e apoio durante as intervenções nos processos de fim de vida, e à família, principalmente como facilitadora deste processo. Nesses momentos, revela-se uma visão integral da pessoa. Conclusões Há consenso sobre a abordagem e intervenções da terapia ocupacional identificadas pelos participantes, sendo semelhante ao descrito na literatura estrangeira. Faltam diretrizes de políticas públicas locais que permitam uma melhor definição do papel do profissional nesse contexto.
Abstract Introduction The intervention of occupational therapy with elderly people in end-of-life processes in hospital contexts presents short scientific documentation in Chile. Given the increase in the elderly population, their high prevalence of chronic diseases, and the hospital mortality rates, the need to review the interventions carried out in the end-of-life processes of the elderly are identified. Objective To characterize occupational therapy interventions with elderly people who are in their end-of-life process, from the perception of occupational therapists dedicated to the area, in public hospital contexts in Chile. Method The research is of a qualitative type framed within the constructivist paradigm under the phenomenological approach, using the semi-structured interview as an information collection technique and subsequent content analysis. The study sample is made up of occupational therapists who work in public hospitals in the country. Results Occupational therapists are identified as agents that provide humanizing care and support during interventions in end-of-life processes, and families mainly as a facilitator of the same. In these processes, an integral vision of the person is revealed. Conclusions There is consensus on the occupational therapy approach and interventions identified by the participants, and it is similar to what is described in the international literature. There is a lack of local public policy guidelines that allow a better definition of the professional role in this context.
RESUMO
Seed coating is an alternative delivery system for beneficial plant microorganisms into the soil. Although seed coats are widely used for the application of agrochemicals, the incorporation of beneficial microorganisms has not been explored deeply and their survival on seeds while in storage is unknown. The study aimed to evaluate the effect of the coating process on microbial survival and on plant growth promotion. Two coating formulations were designed, and assessed by two coating processes: rotating drum and fluidized bed. The rotating drum process resulted in more uniform coatings than in the fluidized bed process. In addition, with this coating technique, lower viability losses over time were observed. The rotatory drum prototype containing a biopolymer and a clay mineral derivate (P90) showed the best behavior at the three temperatures evaluated, with superior viabilities compared to the other prototypes and the lowest loss of viability after 12 months. The formulation of this coating prototype may preserve the viability of Trichoderma koningiopsis Th003 up to 15 months at 8 °C, 9 months at 18 °C, and 3 months at 28 °C, which are very promising shelf-life results. Regarding the effect of seed coating on plant growth, prototypes showed higher yields > 16% than the control, comparable to the conventional use of Tricotec® WG, which may reduce the number of applications and water consumption for dissolution of the inoculant. The results demonstrated that the formulation composition, as well as the coating process may impact the microbial survival on seeds.
Assuntos
Hypocreales , Oryza , Oryza/crescimento & desenvolvimento , Oryza/microbiologia , Desenvolvimento Vegetal , SementesRESUMO
Introducción: Existen estrategias direccionadas a mejorar el rendimiento de los deportistas, algunas estableciendo recomendaciones respecto a la hidratación y reposición de líquidos, con el propósito de asegurar un balance hídrico adecuado en todas las etapas de la práctica deportiva. Sin embargo, existe una carencia de instrumentos adecuados y confiables que permitan explorar esta temática. Objetivo: La presente investigación tiene como objetivo validar por contenido y evaluar la fiabilidad del instrumento "Conocimiento, actitud y comportamiento respecto a la hidratación y reposición de líquidos" en deportistas adolescentes y adultos jóvenes en Chile. Métodos: La adaptación cultural se realizó a través del método Delphi con un panel de expertos en el área, para la evaluación de la fiabilidad se aplicó el cuestionario de manera online a una muestra de 384 deportistas de diferentes disciplinas en dos oportunidades para determinar la estabilidad temporal. Resultados: Todos los ítems lograron porcentajes de acuerdo superior al 80% según el estadístico V de Aiken, en relación con la fiabilidad se obtuvo un Alfa de Cronbach de 0,78 lo que evidencia una consistencia interna aceptable, adicionalmente se obtuvo un Coeficiente de Correlación intraclase de 0,64 entre las dos aplicaciones del cuestionario presentando una fiabilidad regular a buena. Conclusión: Este cuestionario puede ser empleado como una herramienta confiable para ser utilizada en futuras investigaciones en el área de la nutrición deportiva, además como un instrumento que aporta al quehacer de distintos profesionales para apoyar a planificar y evaluar estrategias que propendan al mejoramiento del rendimiento deportivo.
Introduction: There are strategies aimed at improving the performance of athletes, some of which establish recommendations regarding hydration and fluid replacement, with the purpose of ensuring an adequate water balance at all stages of sports practice. However, there is a lack of adequate and reliable instruments to explore this issue. Objective: The present research aims to validate the content and evaluate the reliability of the instrument "Knowledge, attitude and behavior regarding hydration and fluid replacement" among adolescent and young adult athletes in Chile. Methods: The cultural adaptation was carried out through the Delphi method with a panel of experts in the area. For the evaluation of reliability, the questionnaire was applied online to a sample of 384 athletes from different disciplines on two occasions to determine temporal stability. Results: All items achieved percentages of agreement higher than 80% according to Aiken's V statistic, in relation to reliability a Cronbach's Alpha of 0.78 was obtained, which shows an acceptable internal consistency, additionally an intraclass Correlation Coefficient of 0.64 was obtained between the two applications of the questionnaire presenting a regular to good reliability. Conclusion: This questionnaire can be used as a reliable tool for future research around sports nutrition, as well as an instrument that contributes to the work of different professionals to support the planning and evaluation of strategies aimed at improving sports performance.
RESUMO
DNA polymerase ß plays a fundamental role in the life cycle of Trypanosoma cruzi since it participates in the kinetoplast DNA repair and replication. This enzyme can be found in two forms in cell extracts of T. cruzi epimastigotes form. The H form is a phosphorylated form of DNA polymerase ß, while the L form is not phosphorylated. The protein kinases which are able to in vivo phosphorylate DNA polymerase ß have not been identified yet. In this work, we purified the H form of this DNA polymerase and identified the phosphorylation sites. DNA polymerase ß is in vivo phosphorylated at several amino acid residues including Tyr35, Thr123, Thr137 and Ser286. Thr123 is phosphorylated by casein kinase 2 and Thr137 and Ser286 are phosphorylated by protein kinase C-like enzymes. Protein kinase C encoding genes were identified in T. cruzi, and those genes were cloned, expressed in bacteria and the recombinant protein was purified. It was found that T. cruzi possesses three different protein kinase C-like enzymes named TcPKC1, TcPKC2, and TcPKC3. Both TcPKC1 and TcPKC2 were able to in vitro phosphorylate recombinant DNA polymerase ß, and in addition, TcPKC1 gets auto phosphorylated. Those proteins contain several regulatory domains at the N-terminus, which are predicted to bind phosphoinositols, and TcPKC1 contains a lipocalin domain at the C-terminus that might be able to bind free fatty acids. Tyr35 is phosphorylated by an unidentified protein kinase and considering that the T. cruzi genome does not contain Tyr kinase encoding genes, it is probable that Tyr35 could be phosphorylated by a dual protein kinase. Wee1 is a eukaryotic dual protein kinase involved in cell cycle regulation. We identified a Wee1 homolog in T. cruzi and the recombinant kinase was assayed using DNA polymerase ß as a substrate. T. cruzi Wee1 was able to in vitro phosphorylate recombinant DNA polymerase ß, although we were not able to demonstrate specific phosphorylation on Tyr35. Those results indicate that there exists a cell signaling pathway involving PKC-like kinases in T. cruzi.
Assuntos
Doença de Chagas , DNA Polimerase beta , Trypanosoma cruzi , Humanos , DNA Polimerase beta/genética , DNA Polimerase beta/metabolismo , Caseína Quinase II/metabolismo , Proteína Quinase C/metabolismoRESUMO
Positive cofactor 4 (PC4) is a transcriptional coactivator that plays important roles in transcription and DNA replication. In mammals, PC4 is phosphorylated by CK2, and this event downregulates its RNA polymerase II (RNAPII) coactivator function. This work describes the effect of fission yeast PC4 phosphorylation on RNAPII transcription in a cell extract, which closely resembles the cellular context. We found that fission yeast PC4 is strongly phosphorylated by the catalytic subunit of CK2 (Cka1), while the regulatory subunit (Ckb1) downregulates the PC4 phosphorylation. The addition of Cka1 to an in vitro transcription assay can diminish the basal transcription from the Ad-MLP promoter; however, the addition of recombinant fission yeast PC4 or Ckb1 can stimulate the basal transcription in a cell extract. Fission yeast PC4 is phosphorylated in a domain which has consensus phosphorylation sites for CK2, and two serine residues were identified as critical for CK2 phosphorylation. Mutation of one of the serine residues in PC4 does not completely abolish the phosphorylation; however, when the two serine residues are mutated, CK2 is no longer able to phosphorylate PC4. The mutant which is not phosphorylated is able to stimulate transcription even though it is previously phosphorylated by Cka1, while the wild type and the point mutant are inactivated by Cka1 phosphorylation, and they cannot stimulate transcription by RNAPII in cell extracts. Those results demonstrate that CK2 can regulate the coactivator function of fission yeast PC4 and suggests that this event could be important in vivo as well.
Assuntos
Caseína Quinase II , Proteínas de Ligação a DNA , RNA Polimerase II , Proteínas de Schizosaccharomyces pombe , Schizosaccharomyces , Caseína Quinase II/genética , Caseína Quinase II/metabolismo , Domínio Catalítico , Extratos Celulares , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Fosforilação , RNA Polimerase II/metabolismo , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Serina/metabolismoRESUMO
The Pneumocystis genus is an opportunistic fungal pathogen that infects patients with AIDS and immunocompromised individuals. The study of this fungus has been hampered due to the inability to grow it in a (defined media/pure) culture. However, the use of modern molecular techniques and genomic analysis has helped researchers to understand its complex cell biology. The transcriptional process in the Pneumocystis genus has not been studied yet, although it is assumed that it has conventional transcriptional machinery. In this work, we have characterized the function of the RNA polymerase II (RNAPII) general transcription factor TFIIB from Pneumocystis carinii using the phylogenetically related biological model Schizosaccharomyces pombe. The results of this work show that Pneumocystis carinii TFIIB is able to replace the essential function of S. pombe TFIIB both in in vivo and in vitro assays. The S. pombe strain harboring the P carinii TFIIB grew slower than the parental wild-type S. pombe strain in complete media and in minimal media. The S. pombe cells carrying out the P. carinii TFIIB are larger than the wild-type cells, indicating that the TFIIB gene replacement confers a phenotype, most likely due to defects in transcription. P. carinii TFIIB forms very weak complexes with S. pombe TATA-binding protein on a TATA box promoter but it is able to form stable complexes in vitro when S. pombe TFIIF/RNAPII are added. P. carinii TFIIB can also replace the transcriptional function of S. pombe TFIIB in an in vitro assay. The transcription start sites (TSS) of the endogenous adh gene do not change when P. carinii TFIIB replaces S. pombe TFIIB, and neither does the TSS of the nmt1 gene, although this last gene is poorly transcribed in vivo in the presence of P. carinii TFIIB. Since transcription by RNA polymerase II in Pneumocystis is poorly understood, the results described in this study are promising and indicate that TFIIB from P. carinii can replace the transcriptional functions of S. pombe TFIIB, although the cells expressing the P. carini TFIIB show an altered phenotype. However, performing studies using a heterologous approach, like this one, could be relevant to understanding the basic molecular processes of Pneumocystis such as transcription and replication.