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1.
Nat Commun ; 15(1): 2908, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38575616

RESUMO

Staging amyloid-beta (Aß) pathophysiology according to the intensity of neurodegeneration could identify individuals at risk for cognitive decline in Alzheimer's disease (AD). In blood, phosphorylated tau (p-tau) associates with Aß pathophysiology but an AD-type neurodegeneration biomarker has been lacking. In this multicenter study (n = 1076), we show that brain-derived tau (BD-tau) in blood increases according to concomitant Aß ("A") and neurodegeneration ("N") abnormalities (determined using cerebrospinal fluid biomarkers); We used blood-based A/N biomarkers to profile the participants in this study; individuals with blood-based p-tau+/BD-tau+ profiles had the fastest cognitive decline and atrophy rates, irrespective of the baseline cognitive status. Furthermore, BD-tau showed no or much weaker correlations with age, renal function, other comorbidities/risk factors and self-identified race/ethnicity, compared with other blood biomarkers. Here we show that blood-based BD-tau is a biomarker for identifying Aß-positive individuals at risk of short-term cognitive decline and atrophy, with implications for clinical trials and implementation of anti-Aß therapies.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Humanos , Proteínas tau/líquido cefalorraquidiano , Peptídeos beta-Amiloides/metabolismo , Encéfalo/metabolismo , Biomarcadores/líquido cefalorraquidiano , Atrofia
2.
Nat Commun ; 15(1): 2615, 2024 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-38521766

RESUMO

Blood phosphorylated tau (p-tau) biomarkers, including p-tau217, show high associations with Alzheimer's disease (AD) neuropathologic change and clinical stage. Certain plasma p-tau217 assays recognize tau forms phosphorylated additionally at threonine-212, but the contribution of p-tau212 alone to AD is unknown. We developed a blood-based immunoassay that is specific to p-tau212 without cross-reactivity to p-tau217. Here, we examined the diagnostic utility of plasma p-tau212. In five cohorts (n = 388 participants), plasma p-tau212 showed high performances for AD diagnosis and for the detection of both amyloid and tau pathology, including at autopsy as well as in memory clinic populations. The diagnostic accuracy and fold changes of plasma p-tau212 were similar to those for p-tau217 but higher than p-tau181 and p-tau231. Immunofluorescent staining of brain tissue slices showed prominent p-tau212 reactivity in neurofibrillary tangles that co-localized with p-tau217 and p-tau202/205. These findings support plasma p-tau212 as a peripherally accessible biomarker of AD pathophysiology.


Assuntos
Doença de Alzheimer , Humanos , Doença de Alzheimer/diagnóstico , Neuropatologia , Plasma , Emaranhados Neurofibrilares , Autopsia , Proteínas tau , Biomarcadores , Peptídeos beta-Amiloides
3.
Alzheimers Dement ; 20(1): 745-751, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37858957

RESUMO

INTRODUCTION: Rapidly progressive dementias (RPDs) are a group of neurological disorders characterized by a rapid cognitive decline. The diagnostic value of blood-based biomarkers for Alzheimer's disease (AD) in RPD has not been fully explored. METHODS: We measured plasma brain-derived tau (BD-tau) and p-tau181 in 11 controls, 15 AD patients, and 33 with RPD, of which 19 were Creutzfeldt-Jakob disease (CJD). RESULTS: Plasma BD-tau differentiated AD from RPD and controls (p = 0.002 and p = 0.03, respectively), while plasma and cerebrospinal fluid (CSF) p-tau181 distinguished AD from RPD (p < 0.001) but not controls from RPD (p > 0.05). The correlation of CSF t-tau with plasma BD-tau was stronger (r = 0.78, p < 0.001) than the correlation of CSF and plasma p-tau181 (r = 0.26, p = 0.04). The ratio BD-tau/p-tau181 performed equivalently to the CSF t-tau/p-tau181 ratio, differentiating AD from CJD (p < 0.0001). DISCUSSION: Plasma BD-tau and p-tau181 mimic their corresponding cerebrospinal fluid (CSF) markers. P-tau significantly increased in AD but not in RPD. Plasma BD-tau, like CSF t-tau, increases according to neurodegeneration intensity.


Assuntos
Doença de Alzheimer , Síndrome de Creutzfeldt-Jakob , Humanos , Doença de Alzheimer/líquido cefalorraquidiano , Proteínas tau/líquido cefalorraquidiano , Síndrome de Creutzfeldt-Jakob/diagnóstico , Síndrome de Creutzfeldt-Jakob/líquido cefalorraquidiano , Encéfalo , Biomarcadores/líquido cefalorraquidiano , Diagnóstico Diferencial , Peptídeos beta-Amiloides/líquido cefalorraquidiano
4.
Alzheimers Dement ; 20(2): 1239-1249, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37975513

RESUMO

INTRODUCTION: Detection of Alzheimer's disease (AD) pathophysiology among individuals with mild cognitive changes and those experiencing subjective cognitive decline (SCD) remains challenging. Plasma phosphorylated tau 217 (p-tau217) is one of the most promising of the emerging biomarkers for AD. However, accessible methods are limited. METHODS: We employed a novel p-tau217 immunoassay (University of Gothenburg [UGOT] p-tau217) in four independent cohorts (n = 308) including a cerebrospinal fluid (CSF) biomarker-classified cohort (Discovery), two cohorts consisting mostly of cognitively unimpaired (CU) and mild cognitively impaired (MCI) participants (MYHAT and Pittsburgh), and a population-based cohort of individuals with SCD (Barcelonaßeta Brain Research Center's Alzheimer's At-Risk Cohort [ß-AARC]). RESULTS: UGOT p-tau217 showed high accuracy (area under the curve [AUC] = 0.80-0.91) identifying amyloid beta (Aß) pathology, determined either by Aß positron emission tomography or CSF Aß42/40 ratio. In individuals experiencing SCD, UGOT p-tau217 showed high accuracy identifying those with a positive CSF Aß42/40 ratio (AUC = 0.91). DISCUSSION: UGOT p-tau217 can be an easily accessible and efficient way to screen and monitor patients with suspected AD pathophysiology, even in the early stages of the continuum.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Humanos , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Proteínas tau/líquido cefalorraquidiano , Disfunção Cognitiva/líquido cefalorraquidiano , Tomografia por Emissão de Pósitrons , Encéfalo , Biomarcadores/líquido cefalorraquidiano
5.
medRxiv ; 2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37873312

RESUMO

INTRODUCTION: Detection of Alzheimer's disease (AD) pathophysiology among cognitively unimpaired individuals and those experiencing subjective cognitive decline (SCD) remains challenging. Plasma p-tau217 is one of the most promising of the emerging biomarkers for AD. However, accessible methods are limited. METHODS: We employed a novel p-tau217 immunoassay (UGOT p-tau217) in four independent cohorts (n=308) including a cerebrospinal fluid (CSF) biomarker-classified cohort (Discovery), two cohorts consisting mostly of cognitively unimpaired participants (MYHAT and Pittsburgh), and a population-based cohort of individuals with SCD (ß-AARC). RESULTS: UGOT p-tau217 showed high accuracy (AUC= 0.80-0.91) identifying Aß pathology, determined either by Aß positron emission tomography or CSF Aß42/40 ratio. In individuals experiencing SCD, UGOT p-tau217 showed high accuracy identifying those with a positive CSF Aß42/40 ratio (AUC= 0.91). DISCUSSION: UGOT p-tau217 can be an easily accessible and efficient way to screen and monitor patients with suspected AD pathophysiology, even in the early stages of the continuum.

6.
JAMA Netw Open ; 6(7): e2321554, 2023 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-37399012

RESUMO

Importance: Blood-based measurements of total tau (T-tau) are commonly used to examine neuronal injury in patients with traumatic brain injury (TBI), but current assays do not differentiate between brain-derived tau (BD-tau) and tau produced in peripheral tissues. A novel assay for BD-tau has recently been reported that selectively quantifies nonphosphorylated tau of central nervous system origin in blood samples. Objectives: To examine the association of serum BD-tau with clinical outcomes in patients with severe TBI (sTBI) and its longitudinal changes over 1 year. Design, Setting, and Participants: This prospective cohort study was conducted at the neurointensive unit at the Sahlgrenska University Hospital, Gothenburg, Sweden, between September 1, 2006, and July 1, 2015. The study included 39 patients with sTBI followed up for up to 1 year. Statistical analysis was performed between October and November 2021. Exposures: Serum BD-tau, T-tau, phosphorylated tau231 (p-tau231), and neurofilament light chain (NfL) measured on days 0, 7, and 365 after injury. Main Outcomes and Measures: Associations of serum biomarkers with clinical outcome and longitudinal change in sTBI. Severity of sTBI was evaluated using the Glasgow Coma Scale at hospital admission, while clinical outcome was assessed with the Glasgow Outcome Scale (GOS) at 1-year follow-up. Participants were classified as having a favorable outcome (GOS score, 4-5) or unfavorable outcome (GOS score, 1-3). Results: Among the 39 patients (median age at admission, 36 years [IQR, 22-54 years]; 26 men [66.7%]) in the study on day 0, the mean (SD) serum BD-tau level was higher among patients with unfavorable outcomes vs those with favorable outcomes (191.4 [190.8] pg/mL vs 75.6 [60.3] pg/mL; mean difference, 115.9 pg/mL [95% CI, 25.7-206.1 pg/mL]), while the other markers had smaller between-group mean differences (serum T-tau, 60.3 pg/mL [95% CI, -22.0 to 142.7 pg/mL]; serum p-tau231, 8.3 pg/mL [95% CI, -6.4 to 23.0 pg/mL]; serum NfL, -5.4 pg/mL [95% CI, -99.0 to 88.3 pg/mL]). Similar results were recorded on day 7. Longitudinally, baseline serum BD-tau concentrations showed slower decreases in the whole cohort (42.2% on day 7 [from 138.6 to 80.1 pg/mL] and 93.0% on day 365 [from 138.6 to 9.7 pg/mL]) compared with serum T-tau (81.5% on day 7 [from 57.3 to 10.6 pg/mL] and 99.0% on day 365 [from 57.3 to 0.6 pg/mL]) and p-tau231 (92.5% on day 7 [from 20.1 to 1.5 pg/mL] and 95.0% on day 365 [from 20.1 to 1.0 pg/mL]). These results did not change when considering clinical outcome, where T-tau decreased twice as fast as BD-tau in both groups. Similar results were obtained for p-tau231. Furthermore, the biomarker levels on day 365 were lower, compared with day 7, for BD-tau but not T-tau or p-tau231. Serum NfL had a different trajectory to the tau biomarkers, with levels increasing by 255.9% on day 7 compared with day 0 (from 86.8 to 308.9 pg/mL) but decreasing by 97.0% by day 365 vs day 7 (from 308.9 to 9.2 pg/mL). Conclusions and Relevance: This study suggests that serum BD-tau, T-tau, and p-tau231 have differential associations with clinical outcome and 1-year longitudinal change in patients with sTBI. Serum BD-tau demonstrated utility as a biomarker to monitor outcomes in sTBI and can provide valuable information regarding acute neuronal damage.


Assuntos
Lesões Encefálicas Traumáticas , Adulto , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Biomarcadores , Encéfalo , Escala de Coma de Glasgow , Estudos Prospectivos , Feminino
7.
Alzheimers Dement ; 19(10): 4764-4770, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37232524

RESUMO

INTRODUCTION: We investigated the effects of matrix type and reagent batch changes on diagnostic performances and longitudinal trajectories of brain-derived tau (BD-tau). METHODS: We evaluated (i) Cohort 1: paired EDTA plasma and serum from Alzheimer biomarker-positive older adults versus controls (n = 26); and (ii) Cohort 2: n = 79 acute ischemic stroke patients with 265 longitudinal samples across four time points. RESULTS: In Cohort 1, plasma and serum BD-tau were strongly correlated (rho = 0.96, p < 0.0001) with similar diagnostic performances (AUCs >99%) and correlations with CSF total-tau (rho = 0.93-0.94, p < 0.0001). However, absolute concentrations were ∼40% higher in plasma versus serum. In Cohort 2, first and repeated BD-tau measurements showed a near-perfect correlation (rho = 0.96, p < 0.0001), with no significant between-batch concentration differences. In longitudinal analyses, substituting ∼10% of the first-run concentrations for the remeasured values showed overlapping estimated trajectories without significant differences at any time point. DISCUSSION: BD-tau has equivalent diagnostic accuracies, but non-interchangeable absolute concentrations, in plasma versus serum. Furthermore, the analytical robustness is unaffected by batch-to-batch reagent variations. HIGHLIGHTS: Brain-derived tau (BD-tau) is a novel blood-based biomarker that quantifies tau protein of CNS origin. Effects of preanalytical handling procedures on the quality and reproducibility of BD-tau measures are unknown. In two cohorts of n = 105 participants, we compared BD-tau concentrations and diagnostic performances in paired plasma and serum samples, and evaluated impacts of batch-to-batch reagent variations. Paired plasma and serum showed equivalent diagnostic performances to separate amyloid-positive AD from amyloid-negative controls, indicating both can be used independently. Repeated measurements and longitudinal trajectories of plasma BD-tau were unaffected by batch-to-batch reagent variation.


Assuntos
Doença de Alzheimer , AVC Isquêmico , Humanos , Idoso , Proteínas tau/metabolismo , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Reprodutibilidade dos Testes , Encéfalo/metabolismo , Biomarcadores
8.
Brain ; 146(3): 1152-1165, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36572122

RESUMO

Blood-based biomarkers for amyloid beta and phosphorylated tau show good diagnostic accuracies and agreements with their corresponding CSF and neuroimaging biomarkers in the amyloid/tau/neurodegeneration [A/T/(N)] framework for Alzheimer's disease. However, the blood-based neurodegeneration marker neurofilament light is not specific to Alzheimer's disease while total-tau shows lack of correlation with CSF total-tau. Recent studies suggest that blood total-tau originates principally from peripheral, non-brain sources. We sought to address this challenge by generating an anti-tau antibody that selectively binds brain-derived tau and avoids the peripherally expressed 'big tau' isoform. We applied this antibody to develop an ultrasensitive blood-based assay for brain-derived tau, and validated it in five independent cohorts (n = 609) including a blood-to-autopsy cohort, CSF biomarker-classified cohorts and memory clinic cohorts. In paired samples, serum and CSF brain-derived tau were significantly correlated (rho = 0.85, P < 0.0001), while serum and CSF total-tau were not (rho = 0.23, P = 0.3364). Blood-based brain-derived tau showed equivalent diagnostic performance as CSF total-tau and CSF brain-derived tau to separate biomarker-positive Alzheimer's disease participants from biomarker-negative controls. Furthermore, plasma brain-derived tau accurately distinguished autopsy-confirmed Alzheimer's disease from other neurodegenerative diseases (area under the curve = 86.4%) while neurofilament light did not (area under the curve = 54.3%). These performances were independent of the presence of concomitant pathologies. Plasma brain-derived tau (rho = 0.52-0.67, P = 0.003), but not neurofilament light (rho = -0.14-0.17, P = 0.501), was associated with global and regional amyloid plaque and neurofibrillary tangle counts. These results were further verified in two memory clinic cohorts where serum brain-derived tau differentiated Alzheimer's disease from a range of other neurodegenerative disorders, including frontotemporal lobar degeneration and atypical parkinsonian disorders (area under the curve up to 99.6%). Notably, plasma/serum brain-derived tau correlated with neurofilament light only in Alzheimer's disease but not in the other neurodegenerative diseases. Across cohorts, plasma/serum brain-derived tau was associated with CSF and plasma AT(N) biomarkers and cognitive function. Brain-derived tau is a new blood-based biomarker that outperforms plasma total-tau and, unlike neurofilament light, shows specificity to Alzheimer's disease-type neurodegeneration. Thus, brain-derived tau demonstrates potential to complete the AT(N) scheme in blood, and will be useful to evaluate Alzheimer's disease-dependent neurodegenerative processes for clinical and research purposes.


Assuntos
Doença de Alzheimer , Humanos , Doença de Alzheimer/diagnóstico , Peptídeos beta-Amiloides , Proteínas tau , Encéfalo , Biomarcadores
9.
medRxiv ; 2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-38168323

RESUMO

Blood phosphorylated tau (p-tau) biomarkers, including p-tau217, show high associations with Alzheimer's disease (AD) neuropathologic change and clinical stage. Certain plasma p-tau217 assays recognize tau forms phosphorylated additionally at threonine-212, but the contribution of p-tau212 alone to AD is unknown. We developed a blood-based immunoassay that is specific to p-tau212 without cross-reactivity to p-tau217. Thereafter, we examined the diagnostic utility of plasma p-tau212. In five cohorts (n=388 participants), plasma p-tau212 showed high performances for AD diagnosis and for the detection of both amyloid and tau pathology, including at autopsy as well as in memory clinic populations. The diagnostic accuracy and fold changes of plasma p-tau212 were similar to those for p-tau217 but higher than p-tau181 and p-tau231. Immunofluorescent staining of brain tissue slices showed prominent p-tau212 reactivity in neurofibrillary tangles that co-localized with p-tau217 and p-tau202/205. These findings support plasma p-tau212 as a novel peripherally accessible biomarker of AD pathophysiology.

10.
J Card Surg ; 35(2): 304-312, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31765036

RESUMO

INTRODUCTION: Arterial graft physiology influences the long-term outcome of coronary artery bypass grafting (CABG). We studied factors that can affect the overall resistance to flow using internal mammary artery grafting to the left anterior descending artery. METHODS: This was a prospective, nonrandomized observational study of 100 consecutive patients who underwent elective on-pump isolated or combined valve surgery and CABG. Coronary stenoses were assessed using conventional and quantitative coronary angiography assessment. The flow and pulsatility index (PI) of the grafts were assessed by transit-time flowmetry during cardioplegic arrest and at the end of the operation. Fractional polynomials were used to explore linearity, followed by multivariable regression analysis. RESULTS: Univariate analysis demonstrated higher flows at the end of the operation in patients who had higher flows with the cross-clamp on (P < .001), in males (P = .004), in patients with a low PI at the end of the operation (P = .04), and in patients with a larger size of the recipient artery (P = .005). Multivariable regression analysis showed that the graft flow at the end of the operation was significantly associated with the mean flow with the cross-clamp on (P < .001), sex (P = .003), and PI at the end of the operation (P = .003). Concomitant valve surgery did not influence flows. Male patients had 18 mL/min higher flow. CONCLUSIONS: The graft flow at the end of the operation can be determined by the flow with the cross-clamp on, the PI with the cross-clamp off and coronary artery. We reported differences in the graft flows between sexes, and for first the time, we introduced the concepts of "adequate flow" and "resistance-to-forward-flow" for patent coronary grafts.


Assuntos
Ponte de Artéria Coronária/métodos , Artéria Torácica Interna/transplante , Grau de Desobstrução Vascular , Idoso , Velocidade do Fluxo Sanguíneo , Feminino , Humanos , Masculino , Artéria Torácica Interna/fisiologia , Análise Multivariada , Caracteres Sexuais
11.
Open Biol ; 7(9)2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28878040

RESUMO

The urine of bank voles (Myodes glareolus) contains substantial quantities of a small protein that is expressed at much higher levels in males than females, and at higher levels in males in the breeding season. This protein was purified and completely sequenced at the protein level by mass spectrometry. Leucine/isoleucine ambiguity was completely resolved by metabolic labelling, monitoring the incorporation of dietary deuterated leucine into specific sites in the protein. The predicted mass of the sequenced protein was exactly consonant with the mass of the protein measured in bank vole urine samples, correcting for the formation of two disulfide bonds. The sequence of the protein revealed that it was a lipocalin related to aphrodisin and other odorant-binding proteins (OBPs), but differed from all OBPs previously described. The pattern of secretion in urine used for scent marking by male bank voles, and the similarity to other lipocalins used as chemical signals in rodents, suggest that this protein plays a role in male sexual and/or competitive communication. We propose the name glareosin for this novel protein to reflect the origin of the protein and to emphasize the distinction from known OBPs.


Assuntos
Comunicação Animal , Arvicolinae/genética , Lipocalinas/isolamento & purificação , Reprodução/genética , Sequência de Aminoácidos , Animais , Arvicolinae/classificação , Feminino , Expressão Gênica , Lipocalinas/genética , Lipocalinas/ultraestrutura , Lipocalinas/urina , Masculino , Peso Molecular , Feromônios/genética , Filogenia , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Proteínas/genética , Proteínas/ultraestrutura , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Fatores Sexuais
12.
Angew Chem Int Ed Engl ; 55(7): 2564-8, 2016 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-26806850

RESUMO

Azulenesulfonium salts may be readily prepared from the corresponding azulenes by an SE Ar reaction. These azulene sulfonium salts are bench-stable species that may be employed as pseudohalides for cross-coupling. Specifically, their application in Suzuki-Miyaura reactions has been demonstrated with a diverse selection of coupling partners. These azulenesulfonium salts possess significant advantages in comparison with the corresponding azulenyl halides, which are known to be unstable and difficult to prepare in pure form.

13.
J Contin Educ Nurs ; 46(9): 416-24, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26352045

RESUMO

BACKGROUND: A hospital in Taiwan implemented a framework of caring in clinical practice. After the pilot study, the current study was conducted to implement and evaluate the effectiveness of the program. METHOD: One hundred four nurses from two hospitals were recruited for the intervention (n = 50) and comparison (n = 54) groups in a mixed-method, quasi-experimental pre- and postintervention design. Audiovisual materials based on the authentic caring and uncaring experiences of nurses and patients were created as the curriculum content. Role modeling and reflective practice were used as learning strategies. Both groups of nurses and patients completed a pre- and postintervention evaluation of nurse caring behaviors, using the SHARE (Sense patients' needs before they ask, Help patients out, Acknowledge patients' feelings, Respect the dignity and privacy of patients, Explain what is happening) caring behavior measurement. A focus group interview was conducted. RESULTS: The intervention group exhibited higher frequency of caring behavior than the comparison group (p < 0.001). CONCLUSION: Authentic experiences, reflective practice, and online videos were effective teaching strategies in enhancing nurse caring behavior in an online continuing education program.


Assuntos
Instrução por Computador , Educação Continuada em Enfermagem , Empatia , Modelos Educacionais , Modelos de Enfermagem , Relações Enfermeiro-Paciente , Currículo , Avaliação Educacional , Grupos Focais , Humanos , Entrevistas como Assunto , Projetos Piloto , Desenvolvimento de Programas , Taiwan
14.
J Exp Biol ; 218(Pt 18): 2826-9, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26206352

RESUMO

Using immunohistochemistry and western blot analysis, we demonstrate that melanopsin is localised in cells around the central pore of lateral line neuromasts in the African clawed frog, Xenopus laevis. Since melanopsin is a known photoreceptor pigment with diverse functions in vertebrates, we suggest that the lateral line of Xenopus laevis, which is primarily a mechanoreceptor, might also be light sensitive. Potential functions of such photosensitivity are discussed, including its role in mediating locomotor responses following dermal illumination.


Assuntos
Mecanorreceptores/metabolismo , Opsinas de Bastonetes/metabolismo , Xenopus laevis/fisiologia , Animais , Sistema da Linha Lateral/metabolismo , Luz
15.
Front Neuroendocrinol ; 37: 13-28, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25448788

RESUMO

Extraretinal photoreceptors located within the medio-basal hypothalamus regulate the photoperiodic control of seasonal reproduction in birds. An action spectrum for this response describes an opsin photopigment with a λmax of ∼ 492 nm. Beyond this however, the specific identity of the photopigment remains unresolved. Several candidates have emerged including rod-opsin; melanopsin (OPN4); neuropsin (OPN5); and vertebrate ancient (VA) opsin. These contenders are evaluated against key criteria used routinely in photobiology to link orphan photopigments to specific biological responses. To date, only VA opsin can easily satisfy all criteria and we propose that this photopigment represents the prime candidate for encoding daylength and driving seasonal breeding in birds. We also show that VA opsin is co-expressed with both gonadotropin-releasing hormone (GnRH) and arginine-vasotocin (AVT) neurons. These new data suggest that GnRH and AVT neurosecretory pathways are endogenously photosensitive and that our current understanding of how these systems are regulated will require substantial revision.


Assuntos
Proteínas Aviárias/fisiologia , Aves/fisiologia , Hipotálamo/fisiologia , Opsinas/fisiologia , Células Fotorreceptoras de Vertebrados/fisiologia , Estações do Ano , Comportamento Sexual Animal/fisiologia , Animais , Hormônio Liberador de Gonadotropina/biossíntese , Vasotocina/biossíntese
16.
J Contin Educ Nurs ; 45(11): 497-505, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25347085

RESUMO

BACKGROUND: In Taiwan, regulatory bodies mandate that preceptor training programs comprise six mandatory topics used by all teaching hospitals. These programs have little empirical justification. This study explores the training needs of preceptors from the viewpoints of both preceptors and preceptees. METHOD: Investigators used qualitative methods to conduct 17 focus group interviews with 63 preceptors and 24 preceptees from five hospitals in Taiwan. A constant comparative method was used to analyze the data and extract themes and subthemes from participants' experiences. RESULTS: Seven themes were extracted from both preceptor teaching experiences and preceptee learning experiences. Analysis of the empirical data showed that the six mandated topics do not meet the needs of preceptors. This study also documented the concept of "nurses eating their young" for the first time in Taiwan. CONCLUSION: The findings of this study may serve as a reference for redesigning preceptor training programs in Taiwan.


Assuntos
Educação Continuada em Enfermagem/métodos , Mentores/psicologia , Determinação de Necessidades de Cuidados de Saúde , Recursos Humanos de Enfermagem/educação , Recursos Humanos de Enfermagem/psicologia , Preceptoria/métodos , Atitude do Pessoal de Saúde , Grupos Focais , Humanos , Relações Interprofissionais , Entrevistas como Assunto , Desenvolvimento de Pessoal/métodos , Taiwan
17.
J Nurs Res ; 22(2): 90-100, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24821416

RESUMO

BACKGROUND: Little research has investigated the establishment of norms for nursing students' self-directed learning (SDL) ability, recognized as an important capability for professional nurses. An item response theory (IRT) approach was used to establish norms for SDL abilities valid for the different nursing programs in Taiwan. PURPOSES: The purposes of this study were (a) to use IRT with a graded response model to reexamine the SDL instrument, or the SDLI, originally developed by this research team using confirmatory factor analysis and (b) to establish SDL ability norms for the four different nursing education programs in Taiwan. METHODS: Stratified random sampling with probability proportional to size was used. A minimum of 15% of students from the four different nursing education degree programs across Taiwan was selected. A total of 7,879 nursing students from 13 schools were recruited. The research instrument was the 20-item SDLI developed by Cheng, Kuo, Lin, and Lee-Hsieh (2010). IRT with the graded response model was used with a two-parameter logistic model (discrimination and difficulty) for the data analysis, calculated using MULTILOG. Norms were established using percentile rank. RESULTS: Analysis of item information and test information functions revealed that 18 items exhibited very high discrimination and two items had high discrimination. The test information function was higher in this range of scores, indicating greater precision in the estimate of nursing student SDL. Reliability fell between .80 and .94 for each domain and the SDLI as a whole. The total information function shows that the SDLI is appropriate for all nursing students, except for the top 2.5%. SDL ability norms were established for each nursing education program and for the nation as a whole. CONCLUSIONS: IRT is shown to be a potent and useful methodology for scale evaluation. The norms for SDL established in this research will provide practical standards for nursing educators and students in Taiwan.


Assuntos
Educação em Enfermagem/métodos , Instruções Programadas como Assunto/normas , Psicometria/instrumentação , Estudantes de Enfermagem/psicologia , Adolescente , Adulto , Técnica Delfos , Análise Fatorial , Feminino , Humanos , Modelos Logísticos , Masculino , Pesquisa em Educação de Enfermagem , Avaliação de Programas e Projetos de Saúde , Estudantes de Enfermagem/estatística & dados numéricos , Taiwan , Adulto Jovem
18.
J Contin Educ Nurs ; 45(3): 124-31, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24527892

RESUMO

BACKGROUND: A hospital in Taiwan committed to implementing a framework of caring in clinical practice. This study was conducted to develop online courses on caring for the hospital's nurses. METHOD: The ADDIE (Analysis, Design, Development, Implementation, and Evaluation) model was applied to develop and evaluate this caring curriculum. Concrete caring and uncaring behaviors were identified through patient and nurse interviews. These were used to make 72 instructional videos and five live-action movies. Evaluation tools included quizzes, self-evaluations, focus group interviews, and a measurement of caring behavior. Patients used the same instrument to evaluate the nurses. RESULTS: Nurses' self-evaluations showed positive results. No significant difference was found between pre- and postcourse patient evaluations. CONCLUSION: This study shows the usefulness of ADDIE and provides a model for how research data and results can be used to inform administratively mandated organizational change. It also provides evidence on the effects of caring education.


Assuntos
Educação Continuada em Enfermagem , Modelos Educacionais , Sistemas On-Line , Educação a Distância , Avaliação Educacional , Humanos , Determinação de Necessidades de Cuidados de Saúde , Desenvolvimento de Programas , Avaliação de Programas e Projetos de Saúde , Taiwan
19.
J Contin Educ Nurs ; 44(4): 186-92, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23458078

RESUMO

BACKGROUND: To promote the quality of nursing care, a hospital in Taiwan committed to implementing its SHARE framework for clinical practice. This study was conducted to develop caring content for the SHARE framework in the form of online continuing education videos. METHODS: Five focus group interviews were conducted with 19 exemplary nurses. A constant comparative method was used to extract caring themes that were integrated into the five components of SHARE: S: Sense patient's needs; H: Help patient out; A: Acknowledge patient's feelings; R: Respect patient's dignity and privacy; E: Explain what is happening. RESULTS: Concrete caring behaviors consistent with SHARE were identified. Real-world scenarios were used to produce five videos demonstrating the components of SHARE for use in online caring education. CONCLUSION: This project offers a new strategy for strengthening caring behavior in nurse-patient interactions and may help to establish a model for caring in nursing continuing education in Taiwan.


Assuntos
Educação a Distância , Educação Continuada em Enfermagem , Empatia , Relações Enfermeiro-Paciente , Sistemas On-Line , Grupos Focais , Humanos , Desenvolvimento de Programas , Taiwan , Gravação em Vídeo
20.
PLoS One ; 7(4): e34531, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22496826

RESUMO

Photosensitive retinal ganglion cells (pRGCs) respond to light from birth and represent the earliest known light detection system to develop in the mouse retina. A number of morphologically and functionally distinct subtypes of pRGCs have been described in the adult retina, and have been linked to different physiological roles. We have previously identified two distinct isoforms of mouse melanopsin, Opn4L and Opn4S, which are generated by alternate splicing of the Opn4 locus. These isoforms are differentially expressed in pRGC subtypes of the adult mouse retina, with both Opn4L and Opn4S detected in M1 type pRGCs, and only Opn4L detected in M2 type pRGCs. Here we investigate the developmental expression of Opn4L and Opn4S and show a differential profile of expression during postnatal development. Opn4S mRNA is detected at relatively constant levels throughout postnatal development, with levels of Opn4S protein showing a marked increase between P0 and P3, and then increasing progressively over time until adult levels are reached by P10. By contrast, levels of Opn4L mRNA and protein are low at birth and show a marked increase at P14 and P30 compared to earlier time points. We suggest that these differing profiles of expression are associated with the functional maturation of M1 and M2 subtypes of pRGCs. Based upon our data, Opn4S expressing M1 type pRGCs mature first and are the dominant pRGC subtype in the neonate retina, whereas increased expression of Opn4L and the maturation of M2 type pRGCs occurs later, between P10 and P14, at a similar time to the maturation of rod and cone photoreceptors. We suggest that the distinct functions associated with these cell types will develop at different times during postnatal development.


Assuntos
Retina/crescimento & desenvolvimento , Retina/metabolismo , Opsinas de Bastonetes/biossíntese , Animais , Perfilação da Expressão Gênica , Camundongos , Camundongos Endogâmicos C3H , Isoformas de Proteínas/biossíntese , Células Ganglionares da Retina/metabolismo
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