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1.
J Asthma ; : 1-10, 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38748873

RESUMO

OBJECTIVE: Der f 2, a major allergen derived from Dermatophagoides farinae, is a leading cause of allergic asthma. IL-6 and GM-CSF play essential roles in the exacerbation of asthma. However, the mechanical act by which Der f 2 mediates the expression of IL-6, IL-8, and GM-CSF in airway epithelial cells remains incompletely elucidated. Herein, we aimed to explore the effect of Der f 2 on IL-6 and GM-CSF expression in the human airway epithelial cell BEAS-2B and A549. METHODS: Recombinant Der f 2 (rDf2) was acquired using Pichia pastoris. BEAS-2B and A549 cells were used as cell model. The expression of genes and proteins and the involvement of the signaling cascade were assessed using RT-PCR, quantitative real-time PCR (qPCR), Western blotting, and ELISA, respectively. RESULTS: Our findings showed that rDf2 significantly induced mRNA expression and protein production of IL-6 and GM-CSF in BEAS-2B and A549 cells. In contrast, rDf2 did not influence IL-8 expression or production in both cells. Mechanistic studies revealed that rDf2 triggered activation of the p38 MAPK and JNK. Inhibition of p38, but not JNK, significantly attenuated rDf2-induced IL-6 and GM-CSF expression and production. CONCLUSION: This study demonstrates that Der f 2 promotes the expression and production of the pro-inflammatory cytokines IL-6 and GM-CSF in airway epithelial cells via activation of the p38 signaling pathway. These findings provide insights into the molecular mechanisms that Der f 2 may exacerbate airway inflammation.

2.
Int J Colorectal Dis ; 38(1): 11, 2023 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-36633697

RESUMO

PURPOSE: In 2019, in Australia, there were 500,000 people aged 85 and over. Traditionally, clinicians have adopted the view that surgery is not desirable in this cohort due to increasing perioperative risk, perceived minimal clinical benefit, and shortened life expectancy. This cohort study is aimed at investigating postoperative outcomes from elective and non-elective colorectal cancer surgery in patients aged 80 and over. METHODS: A retrospective analysis was conducted on patients from 2010 to 2020 on a prospectively maintained colorectal database. Patients aged over 80 who underwent surgical resection for colorectal cancer were reviewed. Oncological characteristics, short-term outcomes, overall survival, and relapse-free survival rates were analysed. RESULTS: A total of 832 patients were identified from the database. Females comprised 55% of patients aged 80 and above. The median age was 84 for octogenarians and 92 for nonagenarians. Most patients were ASA 2 (212) or ASA 3 (501). ASA 3 and 4 and stage III pathology were associated with higher postoperative complications. Fifty percent of over 80 s and 37% of over 90 s were surgically discharged to their own home. Overall survival at 30, 180, and 360 days and 5 years was 98.1%, 93.1%, 87.2%, and 57.2% for the over 80 s and 98.1%, 88.9%, 74.9%, and 24.4% for the over 90 s. CONCLUSION: Our results demonstrate that surgical treatment of older patients is safe with acceptable short-, medium-, and long-term survival. Nonetheless, efforts are needed to reduce the rates of complications in older patients, including utilisation of multi-disciplinary teams to assess the optimal treatment strategy and postoperative care.


Assuntos
Neoplasias Colorretais , Procedimentos Cirúrgicos do Sistema Digestório , Idoso de 80 Anos ou mais , Feminino , Humanos , Idoso , Masculino , Estudos Retrospectivos , Estudos de Coortes , Neoplasias Colorretais/patologia , Recidiva Local de Neoplasia , Procedimentos Cirúrgicos do Sistema Digestório/efeitos adversos , Complicações Pós-Operatórias/etiologia , Resultado do Tratamento
3.
Cereb Cortex ; 31(2): 974-992, 2021 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-32935833

RESUMO

It is generally assumed that the encoding of a single event generates multiple memory representations, which contribute differently to subsequent episodic memory. We used functional magnetic resonance imaging (fMRI) and representational similarity analysis to examine how visual and semantic representations predicted subsequent memory for single item encoding (e.g., seeing an orange). Three levels of visual representations corresponding to early, middle, and late visual processing stages were based on a deep neural network. Three levels of semantic representations were based on normative observed ("is round"), taxonomic ("is a fruit"), and encyclopedic features ("is sweet"). We identified brain regions where each representation type predicted later perceptual memory, conceptual memory, or both (general memory). Participants encoded objects during fMRI, and then completed both a word-based conceptual and picture-based perceptual memory test. Visual representations predicted subsequent perceptual memory in visual cortices, but also facilitated conceptual and general memory in more anterior regions. Semantic representations, in turn, predicted perceptual memory in visual cortex, conceptual memory in the perirhinal and inferior prefrontal cortex, and general memory in the angular gyrus. These results suggest that the contribution of visual and semantic representations to subsequent memory effects depends on a complex interaction between representation, test type, and storage location.


Assuntos
Memória/fisiologia , Percepção Visual/fisiologia , Adolescente , Adulto , Mapeamento Encefálico , Formação de Conceito , Feminino , Giro do Cíngulo/diagnóstico por imagem , Giro do Cíngulo/fisiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Memória Episódica , Testes Neuropsicológicos , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/fisiologia , Semântica , Córtex Visual/diagnóstico por imagem , Córtex Visual/fisiologia , Adulto Jovem
4.
Sensors (Basel) ; 22(3)2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-35161525

RESUMO

Music can generate a positive effect in runners' performance and motivation. However, the practical implementation of music intervention during exercise is mostly absent from the literature. Therefore, this paper designs a playback sequence system for joggers by considering music emotion and physiological signals. This playback sequence is implemented by a music selection module that combines artificial intelligence techniques with physiological data and emotional music. In order to make the system operate for a long time, this paper improves the model and selection music module to achieve lower energy consumption. The proposed model obtains fewer FLOPs and parameters by using logarithm scaled Mel-spectrogram as input features. The accuracy, computational complexity, trainable parameters, and inference time are evaluated on the Bi-modal, 4Q emotion, and Soundtrack datasets. The experimental results show that the proposed model is better than that of Sarkar et al. and achieves competitive performance on Bi-modal (84.91%), 4Q emotion (92.04%), and Soundtrack (87.24%) datasets. More specifically, the proposed model reduces the computational complexity and inference time while maintaining the classification accuracy, compared to other models. Moreover, the size of the proposed model for network training is small, which can be applied to mobiles and other devices with limited computing resources. This study designed the overall playback sequence system by considering the relationship between music emotion and physiological situation during exercise. The playback sequence system can be adopted directly during exercise to improve users' exercise efficiency.


Assuntos
Música , Algoritmos , Inteligência Artificial , Emoções , Redes Neurais de Computação
5.
Aust Crit Care ; 35(1): 34-39, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34654611

RESUMO

BACKGROUND: Coronavirus disease-2019 (COVID-19) has effected major changes to healthcare delivery within acute care settings. Rapid response calls (RRCs) in healthcare organisations have been effective at identifying and urgently managing acute clinical deterioration. Code-95 RRC were introduced to prewarn healthcare workers (HCWs) attending to patients suspected or confirmed with COVID-19 infection. AIMS: The primary aim of the study was to identify the personal impact of the COVID-19 pandemic on HCWs involved in attending Code-95 RRC. We sought to evaluate their perception of risks and effects on wellbeing and identify potential opportunities for improvement at organisational levels. METHODS: We undertook a detailed survey on HCWs attending Code-95 RRCs, including questions that sought to understand the impact of the pandemic as well as their perception of infection risk and emotional wellbeing. This was a substudy of the prospective cross-sectional single-centre survey of HCWs that was conducted over a 3-week period at Frankston Hospital, Victoria, Australia. We adopted a quantitative content analysis approach for free-text responses in this secondary analysis. RESULTS: Four hundred two free-text comments were received from 297 respondents and were analysed. More than two-thirds (68%, 223/297) were female. Of all comments, 39% (155/402) were related to organisational issues including communication, confusion due to constantly changing infection control policies, and insufficient training. Thirty-three percent of comments (133/402) raised issues regarding the adequacy of personal protective equipment. Anxiety was reported in 25% of comments (101/402) with concerns predominantly relating to emotional stress and fatigue, risks of virus exposure and transmitting the infection to others, and COVID-19 precautions impairing care delivery. CONCLUSION(S): Our study raises important issues that have relevance for all healthcare organisations in the management of patients with COVID-19. These include the importance of improving communication, especially when infection control policies are revised, optimising training, maintaining adequate personal protective equipment, and HCW support. Early recognition and management of these issues are crucial to maintain optimal healthcare delivery.


Assuntos
COVID-19 , Pandemias , Estudos Transversais , Feminino , Pessoal de Saúde , Humanos , Percepção , Estudos Prospectivos , SARS-CoV-2 , Vitória
6.
J Neurosci ; 40(9): 1920-1930, 2020 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-31974208

RESUMO

The declarative memory system allows us to accurately recognize a countless number of items and events, particularly those strengthened by repeated exposure. However, increased familiarity due to repetition can also lead to false recognition of related but new items, particularly when mechanisms supporting fine-grain mnemonic discrimination fail. The hippocampus is thought to be particularly important in separating overlapping cortical inputs during encoding so that similar experiences can be differentiated. In the current study of male and female human subjects, we examine how neural pattern similarity between repeated exemplars of a given concept (e.g., apple) influences true and false memory for target or lure images. Consistent with past work, we found that subsequent true recognition was related to pattern similarity between concept exemplars and the entire encoding set (global encoding similarity), particularly in ventral visual stream. In addition, memory for an individual target exemplar (a specific apple) could be predicted solely by the degree of pattern overlap between the other exemplars (different apple pictures) of that concept (concept-specific encoding similarity). Critically, subsequent false memory for lures was mitigated when high concept-specific similarity in cortical areas was accompanied by differentiated hippocampal representations of the corresponding exemplars. Furthermore, both true and false memory entailed the reinstatement of concept-related information at varying levels of specificity. These results link both true and false memory to a measure of concept strength expressed in the overlap of cortical representations, and importantly, illustrate how the hippocampus serves to separate concurrent cortical overlap in the service of detailed memory.SIGNIFICANCE STATEMENT In some instances, the same processes that help promote memory for a general idea or concept can also hinder more detailed memory judgments, which may involve differentiating between closely related items. The current study shows that increased overlap in cortical representations for conceptually-related pictures is associated with increased recognition of repeated concept pictures. Whether similar lure items were falsely remembered as old further depended on the hippocampus, where the presence of more distinct representations protected against later false memory. This work suggests that the differentiability of brain patterns during perception is related to the differentiability of items in memory, but that fine-grain discrimination depends on the interaction between cortex and hippocampus.


Assuntos
Córtex Cerebral/fisiologia , Hipocampo/fisiologia , Memória/fisiologia , Repressão Psicológica , Adulto , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Rememoração Mental/fisiologia , Reconhecimento Fisiológico de Modelo/fisiologia , Estimulação Luminosa , Reconhecimento Psicológico , Vias Visuais/fisiologia , Adulto Jovem
7.
J Cogn Neurosci ; 33(1): 77-88, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32812826

RESUMO

Although a large proportion of the lexicon consists of abstract concepts, little is known about how they are represented by the brain. Here, we investigated how the mind represents relations shared between sets of mental representations that are superficially unrelated, such as car-engine and dog-tongue, but that nonetheless share a more general, abstract relation, such as whole-part. Participants saw a pair of words on each trial and were asked to indicate whether they could think of a relation between them. Importantly, they were not explicitly asked whether different word pairs shared the same relation, as in analogical reasoning tasks. We observed representational similarity for abstract relations in regions in the "conceptual hub" network, even when controlling for semantic relatedness between word pairs. By contrast, we did not observe representational similarity in regions previously implicated in explicit analogical reasoning. A given relation was sometimes repeated across sequential word pairs, allowing us to test for behavioral and neural priming of abstract relations. Indeed, we observed faster RTs and greater representational similarity for primed than unprimed trials, suggesting that mental representations of abstract relations are transiently activated on this incidental analogy task. Finally, we found a significant correlation between behavioral and neural priming across participants. To our knowledge, this is the first study to investigate relational priming using functional neuroimaging and to show that neural representations are strengthened by relational priming. This research shows how abstract concepts can be brought to mind momentarily, even when not required for task performance.


Assuntos
Resolução de Problemas , Semântica , Encéfalo , Formação de Conceito , Humanos , Análise e Desempenho de Tarefas
8.
Appl Microbiol Biotechnol ; 105(24): 9125-9136, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34811605

RESUMO

Product retention in hollow fibers is a common issue in ATF-based cell culture system. In this study, the effects of four major process factors on product (therapeutic antibody/recombinant protein) retention were investigated using Chinese hamster ovary cell. Hollow fibers made of polysulfone presented a product retention rate from 15% ± 8 to 43% ± 18% higher than those made of polyether sulfone varying with specific processes. Higher harvest flowrate and ATF exchange rate increased product retention by 13% ± 10% and up to 31% ± 13%, respectively. Hollow fibers with larger pore sizes (0.65 µm) appeared to have increased product retention by 38% ± 7% compared with smaller ones (0.2 µm) in this study. Further investigation revealed that the effects of pore size on retention could be correlated to the particle size distribution in the cell culture broth. A hollow fiber with a larger pore size (>0.5 µm) may reduce protein retention when small particles (approximately 0.01-0.2 µm in diameter) are dominant in the culture. However, if majority of the particles are larger than 0.2 µm in diameter, hollow fiber with smaller pore sizes (0.2 µm) could be a solution to reducing product retention. Alternatively, process optimization may modulate particle size distribution towards reduced production retention with selected ATF hollow fibers. This study for the first time highlights the importance of matching proper pore sizes of hollow fibers with the cell culture particles distribution and offers methods to reducing product retention and ATF column clogging in perfusion cell cultures. KEY POINTS: The material of ATF column could impact product retention during perfusion culture. Higher harvest flowrate and ATF exchange rate increased product retention. Matching culture particle size and ATF pore size is critical for retention modulation.


Assuntos
Reatores Biológicos , Técnicas de Cultura de Células , Animais , Células CHO , Cricetinae , Cricetulus , Perfusão
9.
Intern Med J ; 51(4): 494-505, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33890372

RESUMO

BACKGROUND: To allow better allocation of staff and resources, rapid response teams attending to acutely deteriorating or aggressive patients with suspected or confirmed COVID-19 infection were pre-warned with the announcement of 'Code-95' with calls. AIM: To assess healthcare worker (HCW) perspectives on pre-warning rapid response calls (RRC) with 'Code-95' in announcements when attending to deteriorating or aggressive patients with suspected/confirmed COVID-19 infection. METHODS: Design: prospective cross-sectional single-centre survey of HCW over a 3-week period. SETTING: tertiary public hospital. PARTICIPANTS: HCW caring for deteriorating or aggressive patients. MAIN OUTCOME MEASURES: the primary outcome was to assess HCW perspectives in attending Code-95 calls. Secondary outcomes were to identify any differences related to craft group, age, experience or presence of comorbidities. RESULTS: A total of 297 responses was analysed; 86.7% of HCW (n = 257) attending Code-95 calls reported anxiety. Medical staff reported greater anxiety in comparison to nursing staff (93.8% vs 78.5%; P = 0.002). Efferent team reported higher anxiety in contrast to afferent team (92.6% vs 58.8%; P = 0.021). There was no significant difference in perceived anxiety based on age (≤40 vs >40 years of age), years of experience (≤5 vs >5 years), comorbidities or mental illness; 54% reported concerns about adequacy of infection-control policies and personal protective equipment; 45% were worried about inadequate training for responding to Code-95 calls. CONCLUSIONS: Most surveyed HCW supported Code-95 announcements pre-warning them of potential COVID-19 exposure when attending a RRC. However, the majority of HCW reported anxiety when attending these calls. Medical and efferent team HCW perceived greater anxiety compared to nursing and afferent team HCW. The Code-95 system to pre-warn rapid response teams may be a useful addition to protecting HCW from infectious diseases, although broader implementation will require greater resourcing, training and support.


Assuntos
COVID-19 , Adulto , Estudos Transversais , Pessoal de Saúde , Humanos , Percepção , Estudos Prospectivos , SARS-CoV-2
10.
J Formos Med Assoc ; 120 Suppl 1: S19-S25, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34112588

RESUMO

BACKGROUND: As COVID-19 has become a pandemic emerging infectious disease it is important to examine whether there was a spatiotemporal clustering phenomenon in the globe during the rapid spread after the first outbreak reported from southern China. MATERIALS AND METHODS: The open data on the number of COVID-19 cases reported at daily basis form the globe were used to assess the evolution of outbreaks with international air link on the same latitude and also including Taiwan. The dynamic Susceptible-Infected-Recovered model was used to evaluate continental transmission from December 2019 to March 2020 before the declaration of COVID-19 pandemic with basic reproductive number and effective reproductive number before and after containment measurements. RESULTS: For the initial COVID-19 outbreak in China, the estimated reproductive number was reduced from 2.84 during the overwhelming outbreaks in early January to 0.43 after the strict lockdown policy. It is very surprising to find there were three countries (including South Korea, Iran, and Italy) and the Washington state of the USA on the 38° North Latitude involved with large-scale community-acquired outbreaks since the first imported COVID-19 cases from China. The propagation of continental transmission was augmented from hotspot to hotspot with higher reproductive number immediately before the declaration of pandemic. By contrast, there was not any large community-acquired outbreak in Taiwan. CONCLUSION: The propagated spatiotemporal transmission from China to other hotspots may explain the emerging pandemic that can only be exempted by timely border control and preparedness of containment measurements according to Taiwan experience.


Assuntos
COVID-19 , Pandemias , COVID-19/transmissão , China/epidemiologia , Controle de Doenças Transmissíveis , Infecções Comunitárias Adquiridas/transmissão , Humanos , Irã (Geográfico)/epidemiologia , Itália/epidemiologia , República da Coreia/epidemiologia , SARS-CoV-2 , Taiwan/epidemiologia , Washington/epidemiologia
11.
J Formos Med Assoc ; 120 Suppl 1: S95-S105, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34108119

RESUMO

BACKGROUND: Vaccine is supposed to be the most effective means to prevent COVID-19 as it may not only save lives but also reduce productivity loss due to resuming pre-pandemic activities. Providing the results of economic evaluation for mass vaccination is of paramount importance for all stakeholders worldwide. METHODS: We developed a Markov decision tree for the economic evaluation of mass vaccination against COVID-19. The effectiveness of reducing outcomes after the administration of three COVID-19 vaccines (BNT162b2 (Pfizer-BioNTech), mRNA-1273 (Moderna), and AZD1222 (Oxford-AstraZeneca)) were modelled with empirical parameters obtained from literatures. The direct cost of vaccine and COVID-19 related medical cost, the indirect cost of productivity loss due to vaccine jabs and hospitalization, and the productivity loss were accumulated given different vaccination scenarios. We reported the incremental cost-utility ratio and benefit/cost (B/C) ratio of three vaccines compared to no vaccination with a probabilistic approach. RESULTS: Moderna and Pfizer vaccines won the greatest effectiveness among the three vaccines under consideration. After taking both direct and indirect costs into account, all of the three vaccines dominated no vaccination strategy. The results of B/C ratio show that one dollar invested in vaccine would have USD $13, USD $23, and USD $28 in return for Moderna, Pfizer, and AstraZeneca, respectively when health and education loss are considered. The corresponding figures taking value of the statistical life into account were USD $176, USD $300, and USD $443. CONCLUSION: Mass vaccination against COVID-19 with three current available vaccines is cost-saving for gaining more lives and less cost incurred.


Assuntos
COVID-19 , Vacinação em Massa , Vacina BNT162 , COVID-19/economia , COVID-19/prevenção & controle , Vacinas contra COVID-19/economia , ChAdOx1 nCoV-19 , Análise Custo-Benefício , Humanos , Vacinação em Massa/economia
12.
J Formos Med Assoc ; 120 Suppl 1: S26-S37, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34083090

RESUMO

BACKGROUND: As Coronavirus disease 2019 (COVID-19) pandemic led to the unprecedent large-scale repeated surges of epidemics worldwide since the end of 2019, data-driven analysis to look into the duration and case load of each episode of outbreak worldwide has been motivated. METHODS: Using open data repository with daily infected, recovered and death cases in the period between March 2020 and April 2021, a descriptive analysis was performed. The susceptible-exposed-infected-recovery model was used to estimate the effective productive number (Rt). The duration taken from Rt > 1 to Rt < 1 and case load were first modelled by using the compound Poisson method. Machine learning analysis using the K-means clustering method was further adopted to classify patterns of community-acquired outbreaks worldwide. RESULTS: The global estimated Rt declined after the first surge of COVID-19 pandemic but there were still two major surges of epidemics occurring in September 2020 and March 2021, respectively, and numerous episodes due to various extents of Nonpharmaceutical Interventions (NPIs). Unsupervised machine learning identified five patterns as "controlled epidemic", "mutant propagated epidemic", "propagated epidemic", "persistent epidemic" and "long persistent epidemic" with the corresponding duration and the logarithm of case load from the lowest (18.6 ± 11.7; 3.4 ± 1.8)) to the highest (258.2 ± 31.9; 11.9 ± 2.4). Countries like Taiwan outside five clusters were classified as no community-acquired outbreak. CONCLUSION: Data-driven models for the new classification of community-acquired outbreaks are useful for global surveillance of uninterrupted COVID-19 pandemic and provide a timely decision support for the distribution of vaccine and the optimal NPIs from global to local community.


Assuntos
COVID-19 , Pandemias , COVID-19/epidemiologia , Infecções Comunitárias Adquiridas/classificação , Surtos de Doenças , Humanos , Aprendizado de Máquina , Modelos Estatísticos , SARS-CoV-2 , Taiwan
13.
Behav Brain Sci ; 42: e302, 2020 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-31896371

RESUMO

Bastin and colleagues present an integrative model of how recollection- and familiarity-based memories are represented in the brain. While they emphasize the role of attribution mechanisms in shaping memory retrieval, prior work examining implicit memory suggests that memory deficits may be better understood by separating attributional biases from the underlying memory traces.


Assuntos
Rememoração Mental , Reconhecimento Psicológico , Viés , Humanos , Memória , Transtornos da Memória
14.
Eur J Neurosci ; 48(11): 3389-3396, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30290029

RESUMO

Depending on a person's goals, different aspects of stored knowledge are accessed. Decades of behavioral work document the flexible use of knowledge, but little neuroimaging work speaks to these questions. We used representational similarity analysis to investigate whether the relationship between brain activity and semantic structure of statements varied in two tasks hypothesized to differ in the degree to which knowledge is accessed: judging truth (semantic task) and judging oldness (episodic task). During truth judgments, but not old/new recognition judgments, a left-lateralized network previously associated with semantic memory exhibited correlations with semantic structure. At a neural level, people activate knowledge representations in different ways when focused on different goals. The present results demonstrate the potential of multivariate approaches in characterizing knowledge storage and retrieval, as well as the ways that it shapes our understanding and long-term memory.


Assuntos
Mapeamento Encefálico , Objetivos , Conhecimento , Memória/fisiologia , Adulto , Encéfalo/fisiologia , Feminino , Humanos , Julgamento/fisiologia , Masculino , Semântica
15.
J Neurosci ; 36(42): 10870-10882, 2016 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-27798141

RESUMO

Rapsyn-deficient myasthenic syndrome is characterized by a weakness in voluntary muscle contraction, a direct consequence of greatly reduced synaptic responses that result from poorly clustered acetylcholine receptors. As with other myasthenic syndromes, the general muscle weakness is also accompanied by use-dependent fatigue. Here, we used paired motor neuron target muscle patch-clamp recordings from a rapsyn-deficient mutant line of zebrafish to explore for the first time the mechanisms causal to fatigue. We find that synaptic responses in mutant fish can follow faithfully low-frequency stimuli despite the reduced amplitude. This is in part helped by a compensatory increase in the number of presynaptic release sites in the mutant fish. In response to high-frequency stimulation, both wild-type and mutant neuromuscular junctions depress to steady-state response levels, but the latter shows exaggerated depression. Analysis of the steady-state transmission revealed that vesicle reloading and release at individual release sites is significantly slower in mutant fish during high-frequency activities. Therefore, reductions in postsynaptic receptor density and compromised presynaptic release collectively serve to reduce synaptic strength to levels that fall below the threshold for muscle action potential generation, thus accounting for use-dependent fatigue. Our findings raise the possibility that defects in motor neuron function may also be at play in other myasthenic syndromes that have been mapped to mutations in muscle-specific proteins. SIGNIFICANCE STATEMENT: Use-dependent fatigue accompanies many neuromuscular myasthenic syndromes, including muscle rapsyn deficiency. Here, using a rapsyn-deficient line of zebrafish, we performed paired motor neuron target muscle patch-clamp recordings to investigate the mechanisms causal to this phenomenon. Our findings indicate that the reduced postsynaptic receptor density resulting from defective rapsyn contributes to weakness, but is not solely responsible for use-dependent fatigue. Instead, we find unexpected involvement of altered transmitter release from the motor neuron. Specifically, slowed reloading of vesicle release sites leads to augmented synaptic depression during repeated action potentials. Even at moderate stimulus frequencies, the depression levels for evoked synaptic responses fall below the threshold for the generation of muscle action potentials. The associated contraction failures are manifest as use-dependent fatigue.


Assuntos
Fadiga/genética , Fadiga/metabolismo , Proteínas Musculares/genética , Neurotransmissores/metabolismo , Peixe-Zebra/fisiologia , Animais , Exocitose/genética , Exocitose/fisiologia , Feminino , Masculino , Neurônios Motores , Contração Muscular/fisiologia , Proteínas Musculares/deficiência , Mutação/genética , Técnicas de Patch-Clamp , Transmissão Sináptica/genética , Transmissão Sináptica/fisiologia
16.
Worldviews Evid Based Nurs ; 14(4): 274-281, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28437836

RESUMO

BACKGROUND AND AIM: The policy of single over double checking of medications has been adopted by many health services; however, nurses' attitudes toward single-checking medications remains unclear. The aim of this study was to explore the attitudes of nurses who single check and administer medications in a setting where single checking has been in place for over a decade. METHODS: A cross-sectional survey design using the validated Single Checking Administration Medication Scale-II to registered nurses (n = 299) working in one metropolitan teaching hospital in Victoria, Australia. Descriptive analyses for participants' demographics were examined and confirmatory factor analysis (CFA) was performed on the survey items to represent the main themes of nurses' attitudes toward single checking. RESULTS: Nurses reported single checking allowed a greater accountability as a professional nurse and more control over drug administration. The efficiency of single checking was welcomed by nurses through reductions in administration time and workplace interruptions. Nurses were more likely to adhere to drug administration procedures when single checking and this process facilitated drug knowledge updates. There was significant variance in attitudes amongst nurses based upon current appointment and years of clinical experience. Free text responses indicated nurses' attitudes were situated in the context of the traditional double-checking system. LINKING EVIDENCE TO ACTION: Understanding nurses' attitudes toward single checking may assist health care services to positively address medication safety. Accountability, efficiency and knowledge are important for nurses when administering medications. Nurses' attitudes are varied when correlated with demographic characteristics.


Assuntos
Atitude do Pessoal de Saúde , Erros de Medicação/prevenção & controle , Enfermeiras e Enfermeiros/psicologia , Adulto , Austrália , Competência Clínica/normas , Estudos Transversais , Feminino , Humanos , Masculino , Erros de Medicação/psicologia , Sistemas de Medicação/normas , Pessoa de Meia-Idade , Autonomia Profissional , Inquéritos e Questionários
17.
J Med Biol Eng ; 37(6): 826-842, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-30220900

RESUMO

The needs for light-weight and soft smart clothing in homecare have been rising since the past decade. Many smart textile sensors have been developed and applied to automatic physiological and user-centered environmental status recognition. In the present study, we propose wearable multi-sensor smart clothing for homecare monitoring based on an economic fabric electrode with high elasticity and low resistance. The wearable smart clothing integrated with heterogeneous sensors is capable to measure multiple human biosignals (ECG and respiration), acceleration, and gyro information. Five independent respiratory signals (electric impedance plethysmography, respiratory induced frequency variation, respiratory induced amplitude variation, respiratory induced intensity variation, and respiratory induced movement variation) are obtained. The smart clothing can provide accurate respiratory rate estimation by using three different techniques (Naïve Bayes inference, static Kalman filter, and dynamic Kalman filter). During the static sitting experiments, respiratory induced frequency variation has the best performance; whereas during the running experiments, respiratory induced amplitude variation has the best performance. The Naïve Bayes inference and dynamic Kalman filter have shown good results. The novel smart clothing is soft, elastic, and washable and it is suitable for long-term monitoring in homecare medical service and healthcare industry.

18.
J Cogn Neurosci ; 28(5): 739-46, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26765947

RESUMO

The "illusory truth" effect refers to the phenomenon whereby repetition of a statement increases its likelihood of being judged true. This phenomenon has important implications for how we come to believe oft-repeated information that may be misleading or unknown. Behavioral evidence indicates that fluency, the subjective ease experienced while processing information, underlies this effect. This suggests that illusory truth should be mediated by brain regions previously linked to fluency, such as the perirhinal cortex (PRC). To investigate this possibility, we scanned participants with fMRI while they rated the truth of unknown statements, half of which were presented earlier (i.e., repeated). The only brain region that showed an interaction between repetition and ratings of perceived truth was PRC, where activity increased with truth ratings for repeated, but not for new, statements. This finding supports the hypothesis that illusory truth is mediated by a fluency mechanism and further strengthens the link between PRC and fluency.


Assuntos
Mapeamento Encefálico , Ilusões/fisiologia , Julgamento/fisiologia , Córtex Perirrinal/fisiologia , Adulto , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Oxigênio/sangue , Córtex Perirrinal/diagnóstico por imagem , Tempo de Reação/fisiologia , Adulto Jovem
19.
Hippocampus ; 26(6): 693-9, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26928884

RESUMO

Considerable neuropsychological and neuroimaging work indicates that the medial temporal lobes are critical for both item and relational memory retrieval. However, there remain outstanding issues in the literature, namely the extent to which medial temporal lobe regions are differentially recruited during incidental and intentional retrieval of item and relational information, and the extent to which aging may affect these neural substrates. The current fMRI study sought to address these questions; participants incidentally encoded word pairs embedded in sentences and incidental item and relational retrieval were assessed through speeded reading of intact, rearranged, and new word-pair sentences, while intentional item and relational retrieval were assessed through old/new associative recognition of a separate set of intact, rearranged, and new word pairs. Results indicated that, in both younger and older adults, anterior hippocampus and perirhinal cortex indexed incidental and intentional item retrieval in the same manner. In contrast, posterior hippocampus supported incidental and intentional relational retrieval in both age groups and an adjacent cluster in posterior hippocampus was recruited during both forms of relational retrieval for older, but not younger, adults. Our findings suggest that while medial temporal lobe regions do not differentiate between incidental and intentional forms of retrieval, there are distinct roles for anterior and posterior medial temporal lobe regions during retrieval of item and relational information, respectively, and further indicate that posterior regions may, under certain conditions, be over-recruited in healthy aging. © 2016 Wiley Periodicals, Inc.


Assuntos
Envelhecimento/fisiologia , Envelhecimento/psicologia , Associação , Rememoração Mental/fisiologia , Reconhecimento Psicológico/fisiologia , Lobo Temporal/fisiologia , Idoso , Análise de Variância , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Testes Neuropsicológicos , Tempo de Reação , Leitura , Lobo Temporal/diagnóstico por imagem , Adulto Jovem
20.
Nephrol Dial Transplant ; 31(8): 1302-9, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-26715763

RESUMO

BACKGROUND: Intradialytic exercise programmes are important because of the deterioration in physical function that occurs in people receiving haemodialysis. Unfortunately, exercise programmes are rarely sustained in haemodialysis clinics. The aim of this study was to determine the efficacy of a sustainable resistance exercise programme on the physical function of people receiving haemodialysis. METHODS: A total of 171 participants from 15 community satellite haemodialysis clinics performed progressive resistance training using resistance elastic bands in a seated position during the first hour of haemodialysis treatment. We used a stepped-wedge design of three groups, each containing five randomly allocated cluster units allocated to an intervention of 12, 24 or 36 weeks. The primary outcome measure was objective physical function measured by the 30-s sit-to-stand (STS) test, the 8-foot timed up and go (TUG) test and the four-square step test. Secondary outcome measures included quality of life, involvement in community activity, blood pressure and self-reported falls. RESULTS: Exercise training led to significant improvements in physical function as measured by STS and TUG. There was a significant average downward change (ß = -1.59, P < 0.01) before the intervention and a significant upward change after the intervention (ß = 0.38, P < 0.01) for the 30-s STS with a similar pattern noted for the TUG. CONCLUSION: Intradialytic resistance training can improve the physical function of people receiving dialysis.


Assuntos
Exercício Físico/fisiologia , Falência Renal Crônica/terapia , Diálise Renal , Treinamento Resistido/métodos , Idoso , Pressão Sanguínea , Feminino , Seguimentos , Humanos , Falência Renal Crônica/fisiopatologia , Masculino , Estudos Prospectivos , Qualidade de Vida , Resultado do Tratamento
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