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1.
Am J Physiol Heart Circ Physiol ; 326(1): H1-H24, 2024 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-37921664

RESUMEN

Cardiovascular magnetic resonance (CMR) imaging has become an essential technique for the assessment of cardiac function and morphology, and is now routinely used to monitor disease progression and intervention efficacy in the clinic. Cardiac fibrosis is a common characteristic of numerous cardiovascular diseases and often precedes cardiac dysfunction and heart failure. Hence, the detection of cardiac fibrosis is important for both early diagnosis and the provision of guidance for interventions/therapies. Experimental mouse models with genetically and/or surgically induced disease have been widely used to understand mechanisms underlying cardiac fibrosis and to assess new treatment strategies. Improving the appropriate applications of CMR to mouse studies of cardiac fibrosis has the potential to generate new knowledge, and more accurately examine the safety and efficacy of antifibrotic therapies. In this review, we provide 1) a brief overview of different types of cardiac fibrosis, 2) general background on magnetic resonance imaging (MRI), 3) a summary of different CMR techniques used in mice for the assessment of cardiac fibrosis including experimental and technical considerations (contrast agents and pulse sequences), and 4) provide an overview of mouse studies that have serially monitored cardiac fibrosis during disease progression and/or therapeutic interventions. Clinically established CMR protocols have advanced mouse CMR for the detection of cardiac fibrosis, and there is hope that discovery studies in mice will identify new antifibrotic therapies for patients, highlighting the value of both reverse translation and bench-to-bedside research.


Asunto(s)
Cardiomiopatías , Corazón , Humanos , Animales , Ratones , Imagen por Resonancia Magnética/métodos , Fibrosis , Progresión de la Enfermedad
2.
J Med Virol ; 96(1): e29323, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-38164047

RESUMEN

Enteroviruses (EVs), single-stranded, positive-sense RNA viruses, can be classified into four species (A-D), which have previously been linked to a diverse range of disease manifestations and infections affecting the central nervous system. In the Enterovirus species B (EV-B), Echovirus type 11 (E11) has been observed to occasionally circulate in Taiwan, which was responsible for an epidemic of enterovirus infections in 2018. Here, 48 clinical specimens isolated in 2003, 2004, 2009, and 2018 were collected for the high-throughput sequencing. Notably, we identified 2018 Taiwanese strains having potential recombinations in the 3D gene, as well as one 2003 strain having a double recombination with E6 and Coxsackievirus B5 in the P2 and P3 regions, respectively. Additionally, one amino acid signature mutated from the Histidine (H) in throat swab specimens to the Tyrosine (Y) in cerebral spinal fluid specimens was detected at position 1496 (or 57) of the genomic coordinate (or 3A gene) to further demonstrate intra-host evolution in different organs. In conclusion, this study identifies potential intertypic recombination events and an intra-host signature mutation in E11 strains, isolated during a 2018 neurological disease outbreak in Taiwan, contributing to our understanding of its evolution and pathogenesis.


Asunto(s)
Infecciones por Enterovirus , Enterovirus , Humanos , Filogenia , Enterovirus Humano B/genética , Enterovirus/genética , Infecciones por Enterovirus/epidemiología , Recombinación Genética
3.
Org Biomol Chem ; 22(8): 1639-1645, 2024 02 21.
Artículo en Inglés | MEDLINE | ID: mdl-38180439

RESUMEN

Sialic acid (SA) is a naturally occurring monosaccharide found in glycoproteins and glycolipids. Changes in the expression of SA are associated with several diseases; thus, the detection of SA is of great significance for biological research, cancer diagnosis, and treatment. Boronic acid analogs have emerged as a promising tool for detecting sugars such as SA due to its reversible covalent bonding ability. In this study, 11 bis-boronic acid compounds and 2 mono-boronic acid compounds were synthesized via a highly efficient Ugi-4CR strategy. The synthesized compounds were subjected to affinity fluorescence binding experiments to evaluate their binding capability to SA. Compound A1 was shown to have a promising binding constant of 2602 ± 100 M-1 at pH = 6.0. Density Functional Theory (DFT) calculations examining the binding modes between A1 and SA indicated that the position of the boronic acid functional group was strongly correlated with its interaction with SA's α-hydroxy acid unit. The DFT calculations were consistent with the observations from the fluorescence experiments, demonstrating that the number and relative positions of the boronic acid functional groups are critical factors in enhancing the binding affinity to SA. DFT calculations of both S and R configuration of A1 indicated that the effect of the S/R configuration of A1 on its binding with ß-sialic acid was insignificant as the Ugi-4CR generated racemic products. A fluorine atom was incorporated into the R2 substituent of A1 as an electron-withdrawing group to produce A5, which possessed a significantly higher capability to bind to SA (Keq = 7015 ± 5 M-1 at pH = 6.0). Finally, A1 and A5 were shown to possess exceptional binding selectivity toward ß-sialic acid under pH of 6.0 and 6.5 while preferring to bind with glucose, fructose, and galactose under pH of 7.0 and 7.5.


Asunto(s)
Ácidos Borónicos , Ácido N-Acetilneuramínico , Ácido N-Acetilneuramínico/química , Ácido N-Acetilneuramínico/metabolismo , Ácidos Borónicos/química , Monosacáridos , Glucosa , Galactosa
4.
Psychogeriatrics ; 23(2): 252-260, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36577404

RESUMEN

BACKGROUND: Elderly homecare service users may reduce their level of social participation and interpersonal interactions due to physiological loss, which may lead to loneliness and depression over the years. However, there is a lack of research on loneliness among older people who use homecare services. The purpose of this study was to examine the factors influencing loneliness among older people using homecare services. METHODS: This is a longitudinal study conducted in communities in Central Taiwan, and data were collected using a structured questionnaire. The questionnaire was first administered as a pre-test to obtain baseline information about the participants, and the same questionnaire was administered as a post-test after 6 months to follow-up. The pre- and post-test questionnaires included five sections, that is, participant demographics, Brief Symptom Rating Scale, Interpersonal Interaction Scale (IIS), Frenchay Activities Index, and UCLA Loneliness Scale (UCLA). RESULTS: A total of 178 participants were recruited in this study. Results indicated that gender, whether participants eat alone or with others at dinner, social media use, perceived economic status, and IIS score were significantly correlated with the loneliness score on the UCLA. Furthermore, there was a significant increase in the loneliness score among male participants in the low loneliness group from baseline to 6 months follow-up. CONCLUSIONS: Gender, presence of others at dinner, social media use, perceived economic status, and interpersonal interaction skills are significant factors that influence loneliness among older people using homecare services. Men tend to experience higher levels of loneliness over time.


Asunto(s)
COVID-19 , Soledad , Humanos , Masculino , Anciano , Pandemias , Estudios Longitudinales , Relaciones Interpersonales
5.
Emerg Infect Dis ; 28(3): 599-607, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35195517

RESUMEN

Vancomycin-resistant Clostridium innocuum was recently identified as an etiologic agent for antibiotic-associated diarrhea in humans. We conducted a case-control study involving 152 C. innocuum-infected patients during 2014-2019 in Taiwan, using 304 cases of Clostridioides difficile infection (CDI) matched by diagnosis year, age (+2 years), and sex as controls. The baseline characteristics were similar between the 2 groups. C. innocuum-infected patients experienced more extraintestinal clostridial infection and gastrointestinal tract-related complications than did patients with CDI. The 30-day mortality rate among C. innocuum-infected patients was 14.5%, and the overall rate was 23.0%. Chronic kidney disease, solid tumor, intensive care unit admission, and shock status were 4 independent risk factors for death. C. innocuum identified from clinical specimens should be recognized as a pathogen requiring treatment, and because of its intrinsic vancomycin resistance, precise identification is necessary to guide appropriate and timely antimicrobial therapy.


Asunto(s)
Infecciones por Clostridium , Firmicutes , Antibacterianos/uso terapéutico , Estudios de Casos y Controles , Preescolar , Infecciones por Clostridium/tratamiento farmacológico , Infecciones por Clostridium/epidemiología , Humanos , Taiwán/epidemiología
6.
Infection ; 50(2): 475-482, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35018587

RESUMEN

PURPOSE: Antimicrobial resistance of nontyphoidal Salmonella (NTS) is a threat to public health worldwide. METHODS: A study on longitudinally collected NTS isolates from a medical center in Taiwan from 2011 to 2019 was undertaken. The multidrug resistance (MDR) and extensively drug resistance (XDR) phenotypes were determined according to internationally used definitions. Molecular serotyping was performed on the resistant NTS. RESULTS: Notably 16.1% (870/5412) of the isolates were MDR, while XDR accounted for 2.1% (111/5412). Both MDR and XDR NTS have increased significantly from 2011 to 2019, especially from 2015 to 2017 (MDR from 9.6% in 2015 to 23.1% 2017; XDR from 1.4% in 2016 to 4.7% in 2017). S. Anatum was the commonest NTS serotype expressing MDR and XDR, in 256/559 (45.8%) and 81/111 (73.0%) of the isolates, respectively, followed by S. Typhimurium and S. Goldcoast. Children < 18 years old contributed to 69.0% of all MDR cases and 64.0% of all XDR cases; majority of them aged less than 5 years. CONCLUSIONS: Increasing MDR and XDR NTS is a threat to public health. MDR and XDR NTS usually caused gastroenteritis in children < 5 years old. Multiple NTS serotypes expressing MDR and XDR indicate multiple food vehicles involved in the transmission. Proper food hygiene practice should never be over-reinforced.


Asunto(s)
Antibacterianos , Farmacorresistencia Bacteriana Múltiple , Antibacterianos/farmacología , Farmacorresistencia Bacteriana Múltiple/genética , Humanos , Salmonella/genética , Serogrupo , Taiwán/epidemiología
7.
J Neuroeng Rehabil ; 19(1): 3, 2022 01 16.
Artículo en Inglés | MEDLINE | ID: mdl-35034661

RESUMEN

BACKGROUND: Error amplification (EA), virtually magnify task errors in visual feedback, is a potential neurocognitive approach to facilitate motor performance. With regional activities and inter-regional connectivity of electroencephalography (EEG), this study investigated underlying cortical mechanisms associated with improvement of postural balance using EA. METHODS: Eighteen healthy young participants maintained postural stability on a stabilometer, guided by two visual feedbacks (error amplification (EA) vs. real error (RE)), while stabilometer plate movement and scalp EEG were recorded. Plate dynamics, including root mean square (RMS), sample entropy (SampEn), and mean frequency (MF) were used to characterize behavioral strategies. Regional cortical activity and inter-regional connectivity of EEG sub-bands were characterized to infer neural control with relative power and phase-lag index (PLI), respectively. RESULTS: In contrast to RE, EA magnified the errors in the visual feedback to twice its size during stabilometer stance. The results showed that EA led to smaller RMS of postural fluctuations with greater SampEn and MF than RE did. Compared with RE, EA altered cortical organizations with greater regional powers in the mid-frontal cluster (theta, 4-7 Hz), occipital cluster (alpha, 8-12 Hz), and left temporal cluster (beta, 13-35 Hz). In terms of the phase-lag index of EEG between electrode pairs, EA significantly reduced long-range prefrontal-parietal and prefrontal-occipital connectivity of the alpha/beta bands, and the right tempo-parietal connectivity of the theta/alpha bands. Alternatively, EA augmented the fronto-centro-parietal connectivity of the theta/alpha bands, along with the right temporo-frontal and temporo-parietal connectivity of the beta band. CONCLUSION: EA alters postural strategies to improve stance stability on a stabilometer with visual feedback, attributable to enhanced error processing and attentional release for target localization. This study provides supporting neural correlates for the use of virtual reality with EA during balance training.


Asunto(s)
Electroencefalografía , Equilibrio Postural , Atención , Retroalimentación , Retroalimentación Sensorial , Humanos
8.
J Formos Med Assoc ; 121(12): 2644-2648, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35871037

RESUMEN

Previous studies had showed that indigenous clones of Salmonella Typhi and S. Paratyphi were originally imported from other countries in Taiwan. We presented the clinical manifestations and laboratory findings of indigenous and imported enteric fever cases in Taiwan in the current decade. We retrospectively reviewed typhoid and paratyphoid fever cases in two medical centers of Chang Gung Memorial Hospitals in 2010-2020. A total of 37 enteric fever cases including 24 typhoid fever and 13 paratyphoid fever were recorded. There were 20 indigenous cases, 16 imported cases, and one indetermined case. Splenomegaly and hepatitis were more frequent in typhoid fever than in paratyphoid fever (P < 0.05). Imported cases had more ciprofloxacin non-susceptibility rate (8/16, 50.0%) than indigenous cases (2/20, 10%). Indigenous ciprofloxacin non-susceptible S. Typhi isolates were found in 2018. One indigenous S. Paratyphi B isolate was multi-drug resistant (MDR) to chloramphenicol, ampicillin, and trimethoprim/sulfamethoxazole.


Asunto(s)
Fiebre Paratifoidea , Fiebre Tifoidea , Humanos , Fiebre Tifoidea/diagnóstico , Fiebre Tifoidea/tratamiento farmacológico , Fiebre Tifoidea/epidemiología , Fiebre Paratifoidea/tratamiento farmacológico , Fiebre Paratifoidea/epidemiología , Fiebre Paratifoidea/microbiología , Salmonella paratyphi A , Estudios Retrospectivos , Taiwán/epidemiología , Antibacterianos/uso terapéutico , Ciprofloxacina/uso terapéutico
9.
Int J Mol Sci ; 23(20)2022 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-36293409

RESUMEN

Mitochondria dysfunction is implicated in the pathogenesis of cardiovascular diseases (CVD). Exercise training is potentially an effective non-pharmacological strategy to restore mitochondrial health in CVD. However, how exercise modifies mitochondrial functionality is inconclusive. We conducted a systematic review using the PubMed; Scopus and Web of Science databases to investigate the effect of exercise training on mitochondrial function in CVD patients. Search terms included "mitochondria", "exercise", "aerobic capacity", and "cardiovascular disease" in varied combination. The search yielded 821 records for abstract screening, of which 20 articles met the inclusion criteria. We summarized the effect of exercise training on mitochondrial morphology, biogenesis, dynamics, oxidative capacity, antioxidant capacity, and quality. Amongst these parameters, only oxidative capacity was suitable for a meta-analysis, which demonstrated a significant effect size of exercise in improving mitochondrial oxidative capacity in CVD patients (SMD = 4.78; CI = 2.99 to 6.57; p < 0.01), but with high heterogeneity among the studies (I2 = 75%, p = 0.003). Notably, aerobic exercise enhanced succinate-involved oxidative phosphorylation. The majority of the results suggested that exercise improves morphology and biogenesis, whereas findings on dynamic, antioxidant capacity, and quality, were inadequate or inconclusive. A further randomized controlled trial is clearly required to explain how exercise modifies the pathway of mitochondrial quantity and quality in CVD patients.


Asunto(s)
Antioxidantes , Enfermedades Cardiovasculares , Humanos , Ejercicio Físico , Enfermedades Cardiovasculares/terapia , Mitocondrias , Succinatos
10.
Water Sci Technol ; 85(5): 1522-1537, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35290229

RESUMEN

Although in a critical position in the economy, the paper industry releases a lot of wastewater that requires adequate treatment for sustainable development. This study presents an application of Life cycle assessment (LCA) with the ReCiPe tool on the wastewater treatment plant (WWTP) of a paper factory in Vietnam to evaluate the environmental effect of the individual techniques in WWTP, especially the internal circulation (IC) reactor, a pioneer and practical anaerobic technology. Both Midpoint and Endpoint categories results demonstrated that chemical use and electricity consumption mainly contributed to the environmental impact in the WWTP. The Dissolved air flotation (DAF) and Moving bed biofilm reactor (MBBR) are classified as effective techniques to reduce the impacts on the environment. Moreover, the comparison of LCA between IC and up-flow anaerobic sludge bed (UASB) shows that IC is the better practically green technique for the environment.


Asunto(s)
Eliminación de Residuos Líquidos , Aguas Residuales , Animales , Biopelículas , Reactores Biológicos , Estadios del Ciclo de Vida , Vietnam , Eliminación de Residuos Líquidos/métodos
11.
J Clin Immunol ; 41(6): 1303-1314, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33963972

RESUMEN

PURPOSE: Female carriers with X-linked chronic granulomatous disease (XL-CGD) who have < 10% reactive oxygen species (ROS) production due to profound X-chromosome inactivation (XCI or lyonization) are more susceptible to infections. We assessed ROS production in Taiwanese female carriers with XL-CGD to investigate whether the level of ROS correlated to their clinical features of infection, autoimmunity, and autoinflammation. METHODS: Clinical course, ROS production, flavocytochrome b558 (Cyto b558) expression, and genetic analysis in carriers were investigated after identifying their index cases between 2004 and 2019. RESULTS: A total of 19 mothers (median 27 years; range 25-60 years) and three of four girls (range 4-6 years) relative to 22 male index XL-CGD cases from 19 unrelated families were enrolled. Approximately half (8/19, 42%) of the mothers had novel one-allele mutations. Twenty-two of the 23 females were carriers. One carrier with de novo [Arg290X]CYBB who suffered from refractory salmonella sepsis and chorioretinitis as an XL-CGD phenotype had extreme XCI, absent Cyto b558 expression, and only 8% ROS production. The remaining carriers had bimodal patterns of Cyto b558 expressions (median 40.2%, 26.8-52.4%) and ROS production (38.3%, range 28.2-54.2%) sufficient to prevent significant infections, although neck lymphadenitis recurred in one mother and sister who had ROS expressions of 28.2% and 38.0%, respectively. However, none of the carriers had manifestations of autoimmunity or autoinflammation (e.g., photosensitivity, aphthous stomatitis, or joint disorders), of which each was seen in approximately one-third of XL-CGD carriers from the Western world. CONCLUSION: One carrier had undetectable Cyto b558 expression and an extremely low ROS production, and consequently presented with an XL-CGD phenotype. One mother and her daughter experienced recurrent neck lymphadenitis despite having sufficient ROS production. Significant autoimmunity/autoinflammation did not develop in any of the carriers. Studies with a longer follow-up period are needed to validate our findings.


Asunto(s)
Pueblo Asiatico/genética , Enfermedad Granulomatosa Crónica/genética , Adulto , Autoinmunidad/genética , Niño , Preescolar , Femenino , Pruebas Genéticas/métodos , Enfermedad Granulomatosa Crónica/metabolismo , Heterocigoto , Humanos , Lactante , Masculino , Mutación/genética , Fenotipo , Especies Reactivas de Oxígeno/metabolismo , Taiwán , Inactivación del Cromosoma X/genética
12.
Clin Sci (Lond) ; 135(2): 327-346, 2021 01 29.
Artículo en Inglés | MEDLINE | ID: mdl-33480422

RESUMEN

A high salt intake exacerbates insulin resistance, evoking hypertension due to systemic perivascular inflammation, oxidative-nitrosative stress and endothelial dysfunction. Angiotensin-converting enzyme inhibitor (ACEi) and angiotensin receptor blockers (ARBs) have been shown to abolish inflammation and redox stress but only partially restore endothelial function in mesenteric vessels. We investigated whether sympatho-adrenal overactivation evokes coronary vascular dysfunction when a high salt intake is combined with insulin resistance in male Goto-Kakizaki (GK) and Wistar rats treated with two different classes of ß-blocker or vehicle, utilising synchrotron-based microangiography in vivo. Further, we examined if chronic carvedilol (CAR) treatment preserves nitric oxide (NO)-mediated coronary dilation more than metoprolol (MET). A high salt diet (6% NaCl w/w) exacerbated coronary microvessel endothelial dysfunction and NO-resistance in vehicle-treated GK rats while Wistar rats showed modest impairment. Microvascular dysfunction was associated with elevated expression of myocardial endothelin, inducible NO synthase (NOS) protein and 3-nitrotyrosine (3-NT). Both CAR and MET reduced basal coronary perfusion but restored microvessel endothelium-dependent and -independent dilation indicating a role for sympatho-adrenal overactivation in vehicle-treated rats. While MET treatment reduced myocardial nitrates, only MET treatment completely restored microvessel dilation to dobutamine (DOB) stimulation in the absence of NO and prostanoids (combined inhibition), indicating that MET restored the coronary flow reserve attributable to endothelium-derived hyperpolarisation (EDH). In conclusion, sympatho-adrenal overactivation caused by high salt intake and insulin resistance evoked coronary microvessel endothelial dysfunction and diminished NO sensitivity, which were restored by MET and CAR treatment in spite of ongoing inflammation and oxidative-nitrosative stress presumably caused by uninhibited renin-angiotensin-aldosterone system (RAAS) overactivation.


Asunto(s)
Antagonistas Adrenérgicos beta/farmacología , Carvedilol/farmacología , Endotelio Vascular/efectos de los fármacos , Resistencia a la Insulina , Antagonistas de Receptores Adrenérgicos beta 1/farmacología , Animales , Angiografía Coronaria , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/fisiopatología , Modelos Animales de Enfermedad , Hipertensión/fisiopatología , Masculino , Metoprolol/farmacología , Óxido Nítrico/metabolismo , Ratas , Ratas Wistar , Cloruro de Sodio Dietético/administración & dosificación
13.
J Neurooncol ; 146(3): 417-426, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32020472

RESUMEN

INTRODUCTION: The failure of immune checkpoint inhibitor (ICPi) on glioblastoma (GBM) treatment underscores the need for improving therapeutic strategy. We aimed to change tumor associated macrophage (TAM) from M2 type (anti-inflammatory) to M1 (pro-inflammatory) type to increase the therapeutic response of ICPi. We proposed that combined rapamycin (R) and hydroxychloroquine (Q) preferentially induce M2 cells death, as fatty acid oxidation was their major source of energy. METHODS: Macrophage polarization was characterized on mice and human macrophage cell lines by specific cytokines stimulation with or without RQ treatment under single culture or co-culture with GBM cell lines. Tumor sizes were evaluated on subcutaneous and intracranial GL261 mice models with or without RQ, anti-PD1 mAb treatment. Tumor volumes assessed by MRI scan and proportions of tumor infiltrating immune cells analyzed by flow cytometry were compared. RESULTS: In vitro RQ treatment decreased the macrophages polarization of M2, increased the phagocytic ability, and increased the lipid droplets accumulation. RQ treatment decreased the expression levels of CD47 and SIRPα on tumor cells and macrophage cells in co-culture experiments. The combination of RQ and anti-PD1 treatment was synergistic in action. Enhanced the intra-tumoral M1/M2 ratio, the CD8/CD4 ratio in the intracranial GL261 tumor model after RQ treatment were evident. CONCLUSION: We provide a rationale for manipulating the macrophage phenotype and increased the therapeutic effect of ICPi. To re-educate and re-empower the TAM/microglia opens an interesting avenue for GBM treatment.


Asunto(s)
Antineoplásicos/administración & dosificación , Neoplasias Encefálicas/inmunología , Glioblastoma/inmunología , Hidroxicloroquina/administración & dosificación , Macrófagos/efectos de los fármacos , Sirolimus/administración & dosificación , Animales , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Neoplasias Encefálicas/metabolismo , Polaridad Celular/efectos de los fármacos , Células Cultivadas , Femenino , Glioblastoma/metabolismo , Humanos , Macrófagos/inmunología , Macrófagos/metabolismo , Ratones , Ratones Endogámicos C57BL , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores
14.
Eur J Appl Physiol ; 120(6): 1305-1317, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32297005

RESUMEN

PURPOSE: This study investigated fatigue-related modulation of common neural inputs to motor units (MUs) under 5 Hz, which determines force precision control. METHODS: Twenty-seven adults performed a sequence of fatiguing contractions. The participants were assessed with a static isometric index abduction at 20% maximal voluntary contraction in the pre-test and post-test. Discharge characteristics of MUs of the first dorsal interosseous muscle were analyzed with decomposed EMG signals. RESULTS: Along with increases in the mean (58.40 ± 11.76 ms → 62.55 ± 10.83 ms, P = 0.029) and coefficient of variation (0.204 ± .014 → 0.215 ± 0.017, P = 0.002) in inter-spike intervals, the fatiguing contraction caused reductions in the mean frequency (16.84 ± 3.31 Hz → 15.59 ± 3.21 Hz, P = 0.027) and spectral dispersions (67.54 ± 4.49 → 62.64 ± 6.76 Hz, P = 0.007) of common neural drive, as estimated with smoothed cumulative motor unit spike trains (SCMUSTs). Stabilogram diffusion analysis of SCMUSTs revealed significant fatigue-related reductions in the long-term effective diffusion coefficient (1.91 ± 0.77 Hz2/s → 1.61 ± 0.61 Hz2/s, P = 0.020) and long-term scaling exponent (0.480 ± 0.013 Hz2/s → 0.471 ± 0.017 Hz2/s, P = 0.014). After fatiguing contraction, mutual information of force fluctuations and SCMUSTs was augmented roughly by 12.95% (P = 0.041). CONCLUSIONS: Muscular fatigue could compress and shift the low-frequency common drive to MUs toward lower spectral bands, thereby enhancing transmission of twitch forces through the muscle-tendon complex with a low-pass filter property. The fatigue-induced changes involve increased closed-loop control of the common modulation of MU discharge rates.


Asunto(s)
Contracción Isométrica/fisiología , Neuronas Motoras/fisiología , Fatiga Muscular/fisiología , Músculo Esquelético/fisiología , Adulto , Electromiografía , Femenino , Humanos , Masculino , Movimiento/fisiología , Adulto Joven
15.
Eur J Appl Physiol ; 120(6): 1437-1447, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32318813

RESUMEN

PURPOSE: Blood flow restriction (BFR) is an innovation in fitness to train muscles with low loads at low oxygen levels. Low-level laser therapy (LLLT) is a bio-energetic approach to alleviate muscle fatigue during resistance training. This study investigated the immediate effect of LLLT pre-conditioning on BFR that accelerates muscle fatigue due to ischemia. METHODS: Fifteen young adults participated in this study of a crossover randomized design. They completed a low-load contraction with various pre-conditioning (blood flow restriction with low-level laser therapy (LLLT + BFR), blood flow restriction with sham low-level laser therapy (BFR), and control). Force fluctuation dynamics, muscle oxygen saturation of hemoglobin and myoglobin (SmO2), and discharge patterns of motor units (MU) were compared. RESULTS: Normalized SmO2 during low-load contractions significantly varied with the pre-contraction protocols (Control (83.6 ± 3.0%) > LLLT + BFR (70.3 ± 2.8%) > BFR (55.4 ± 2.4%). Also, force fluctuations and MU discharge varied with the pre-contraction protocols. Multi-scale entropy and mean frequency of force fluctuations were greater in the LLLT + BFR condition (31.95 ± 0.67) than in the BFR condition (29.47 ± 0.73). The mean inter-spike interval of MUs was greater in the LLLT + BFR condition (53.32 ± 2.70 ms) than in the BFR condition (45.04 ± 1.08 ms). In particular, MUs with higher recruitment thresholds exhibited greater LLLT-related discharge complexity (LLLT + BFR (0.201 ± 0.012) > BFR (0.154 ± 0.006)). CONCLUSIONS: LLLT pre-conditioning can minimize the BFR-related decline in muscle oxygen saturation, leading to force gradation and MU discharge in a cost-effective and complex manner.


Asunto(s)
Contracción Isométrica/fisiología , Terapia por Luz de Baja Intensidad , Fatiga Muscular/fisiología , Músculo Esquelético/fisiología , Entrenamiento de Fuerza , Adulto , Electromiografía , Femenino , Hemodinámica/fisiología , Humanos , Masculino , Músculo Esquelético/irrigación sanguínea , Flujo Sanguíneo Regional/fisiología , Adulto Joven
16.
Environ Toxicol ; 35(5): 619-627, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-31916385

RESUMEN

Cantharidic acid (CA) is the hydrolysis product of the acid anhydride cantharidin, which is a natural toxin secreted by several species of blister beetles. Several studies have indicated that as an inhibitor of protein phosphatase 2 (PP2A), CA induces apoptosis in various human cancer cells. However, the effect of CA on human nasopharyngeal carcinoma (NPC) cells and the underlying pathways have not been addressed. In our current study, we tested the hypothesis that CA treatment reduces the viability of human NPC cells (HONE-1, NPC-39, and NPC-BM) by inducing apoptosis. Results indicated that CA markedly reduced cell viability, which was revealed by the upregulation of caspase activation in extrinsic and intrinsic apoptosis pathways as well as the upregulation of extracellular-signal-regulated kinase 1/2 (ERK1/2), p38, and c-Jun N-terminal kinase 1/2 (JNK1/2) pathways. Coadministration of a p38 inhibitor (SB203580) with CA abolished the activation of caspase proteins. These findings indicated that CA treatment leads to apoptosis in human NPC cells through the upregulation of caspase activation, mediated particularly by the p38 pathway. Hence, CA is a promising therapeutic agent for human NPC.


Asunto(s)
Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Cantaridina/análogos & derivados , Caspasas/metabolismo , Activación Transcripcional/efectos de los fármacos , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Cantaridina/farmacología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Humanos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Carcinoma Nasofaríngeo/metabolismo , Carcinoma Nasofaríngeo/patología , Neoplasias Nasofaríngeas/metabolismo , Neoplasias Nasofaríngeas/patología , Transducción de Señal , Regulación hacia Arriba
17.
J Formos Med Assoc ; 119(12): 1862-1870, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32199716

RESUMEN

BACKGROUND/PURPOSE: Post-stroke dysphagia is a frequent complication. Although most patients with dysphagia recover after the acute phase, some patients require long-term enteral feeding, either through a nasogastric (NG) or gastrostomy tube; the effectiveness of using either tube is still under debate. This study elucidated the natural course of NG tube installation and removal and examined the predictors and associating factors based on clinical and brain imaging data. METHODS: This retrospective cohort study with medical record reviews recruited patients received NG tube installation after their acute stroke events between January 1, 2016, and December 31, 2016. Inclusion criteria were subjects above 20 years of age and with a diagnosis of a newly onset stroke except SAH whose comprehensive clinical and imaging data were available. Survival analysis was performed for the right-censored data because some patients were lost to follow-up after discharge or transferal. RESULTS: In total we recruited 135 patients. Among these patients, the timing of their NG tube removal reached a plateau at 12-16 weeks after stroke. The modified Rankin score on discharge, representing the overall subacute disease status, was the most significant factor. Other clinical variables could be divided into 2 categories: baseline patient characteristics and stroke event severity. Moreover, semi-quantitative brain imaging scores corresponding to the aforementioned 3 categories were correlated significantly. CONCLUSION: In Taiwan, the NG tube removal rate reached a plateau at around 12-16 weeks after stroke onset. Variables related to long-term NG tube use were divided into baseline characteristics of patient and stroke event severity.


Asunto(s)
Trastornos de Deglución , Accidente Cerebrovascular , Análisis de Datos , Trastornos de Deglución/diagnóstico por imagen , Trastornos de Deglución/etiología , Gastrostomía , Humanos , Neuroimagen , Estudios Retrospectivos , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/diagnóstico por imagen , Taiwán
18.
J Aging Phys Act ; 28(6): 934-942, 2020 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-32702665

RESUMEN

This study investigated how visual feedback of virtual error reduction (ER) modified the visuomotor performance of older adults with limited attentional capacity. Error structures of young and older adults during birhythmic force tracking were contrasted when the visualized error size was exact or half of the actual size. As compared with full-size error feedback, ER feedback improved the force tracking symmetry of older adults, but undermined that of young adults. Extended Poincaré analysis revealed that young adults presented greater short-term error variability (mean value of κ-lagged SD1 of the error signal) with ER feedback, which led to a smaller mean value of κ-lagged SD1 of the error signal for older adults. The ER-related task improvement of the older adults was negatively correlated with the size of the tracking errors with real error feedback and positively correlated with ER-related increases in force spectral symmetry and decreases in the mean value of κ-lagged SD1 of the error signal. ER feedback could advance visuomotor tasks for older adults who perform worse with full-size visual feedback by the enhancement of self-efficacy and stabilization of negative internal feedback.

19.
J Aging Phys Act ; 28(1): 114-121, 2020 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-31629359

RESUMEN

This study contrasted the stochastic force component between young and older adults, who performed pursuit tracking/compensatory tracking by exerting in-phase/antiphase forces to match a sinusoidal target. Tracking force was decomposed into the force component containing the target frequency and the nontarget force fluctuations (stochastic component). Older adults with inferior task performance had higher complexity (entropy across time; p = .005) in total force. For older adults, task errors were negatively correlated with force fluctuation complexity (pursuit tracking: r = -.527 to -.551; compensatory tracking: r = -.626 to -.750). Notwithstanding an age-related increase in total force complexity (p = .004), older adults exhibited lower complexity of the stochastic force component than young adults did (low frequency: p = .017; high frequency: p = .035). Those older adults with a higher complexity of stochastic force had better task performance due to the underlying use of a richer gradation strategy to compensate for impaired oscillatory control.


Asunto(s)
Envejecimiento , Contracción Muscular , Músculo Esquelético , Anciano , Entropía , Femenino , Humanos , Contracción Isométrica , Masculino , Procesos Estocásticos , Adulto Joven
20.
J Xray Sci Technol ; 28(4): 773-782, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32417831

RESUMEN

During radiotherapy for head and neck tumours, the oral cavity and cheek area would be inevitably exposed to high energy radiation; thus, the material surface of the teeth, dental restorations with high atomic number, or alloy prosthodontics would generate backscatter electrons that cause the buccal mucosa adjacent to these materials to receive localized high dose enhancement, which primarily leads to side effects or oral mucositis. Based on the size of the adult oral cavity, this study aimed to use acrylic resin to create an oral phantom with two grooves on the left and right sides for placement of three molars. Moreover, the distance between the inner cheek and the side surface of the teeth could be accurately adjusted every 1 mm from 0 to 5 mm. This enhanced the dose in the buccal mucosa during head and neck radiotherapy and made the distribution measurement of the radiation dose simple and feasible at different depths (0-5 mm). Meanwhile, the study employed the film type optically stimulated luminescent dosimeter with a thickness of 0.3 mm to measure the absorbed dose inside the buccal mucosa to reduce the dose interference from radiotherapy. The study fixed three real molars in a row located at the left side of the phantom and employed 6 MV photons and intensity-modulated radiotherapy (IMRT) to treat and simulate oral cancer and measure the attenuation of the molar's backscatter dose from 0 to 5 mm in an up beam direction. The result showed that, in every 3 mm, the phantom had attenuated the enhancement of backscatter dose <3%. The irradiation dose enhancement in a single direction was twice higher than that through IMRT 7 field treatment. These measurement results were consistent with the results of previous studies.


Asunto(s)
Neoplasias de Cabeza y Cuello/radioterapia , Boca/efectos de la radiación , Fantasmas de Imagen , Humanos , Boca/anatomía & histología , Mucosa Bucal/efectos de la radiación , Dosis de Radiación , Dosímetros de Radiación , Radioterapia de Intensidad Modulada , Dispersión de Radiación , Diente/efectos de la radiación
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