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BACKGROUND: Cognitive-motor step training can improve stepping, balance and mobility in people with multiple sclerosis (MS), but effectiveness in preventing falls has not been demonstrated. OBJECTIVES: This multisite randomised controlled trial aimed to determine whether 6 months of home-based step exergame training could reduce falls and improve associated risk factors compared with usual care in people with MS. METHODS: In total, 461 people with MS aged 22-81 years were randomly allocated to usual care (control) or unsupervised home-based step exergame training (120 minutes/week) for 6 months. The primary outcome was rate of falls over 6 months from randomisation. Secondary outcomes included physical, cognitive and psychosocial function at 6 months and falls over 12 months. RESULTS: Mean (standard deviation (SD)) weekly training duration was 70 (51) minutes over 6 months. Fall rates did not differ between intervention and control groups (incidence rates (95% confidence interval (CI)): 2.13 (1.57-2.69) versus 2.24 (1.35-3.13), respectively, incidence rate ratio: 0.96 (95% CI: 0.69-1.34, p = 0.816)). Intervention participants performed faster in tests of choice-stepping reaction time at 6 months. No serious training-related adverse events were reported. CONCLUSION: The step exergame training programme did not reduce falls among people with MS. However, it significantly improved choice-stepping reaction time which is critical to ambulate safely in daily life environment.
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Esclerosis Múltiple , Humanos , Esclerosis Múltiple/complicaciones , Esclerosis Múltiple/terapia , Terapia por Ejercicio , Videojuego de Ejercicio , Factores de Riesgo , Calidad de VidaRESUMEN
OBJECTIVE: To determine whether impairments across cognitive and affective domains provide additional information to sensorimotor deficits for fall prediction among various populations. DESIGN: We pooled data from 5 studies for this observational analysis of prospective falls. SETTING: Community or low-level care facility. PARTICIPANTS: Older people (N=1090; 74.0±9.4y; 579 female); 500 neurologically intact (NI) older people and 3 groups with neurologic disorders (cognitive impairment, n=174; multiple sclerosis (MS), n=111; Parkinson disease, n=305). INTERVENTIONS: None. MAIN OUTCOME MEASURES: Sensorimotor function was assessed with the Physiological Profile Assessment, cognitive function with tests of executive function, affect with questionnaires of depression, and concern about falling with falls efficacy questionnaires. These variables were associated with fall incidence rates, obtained prospectively over 6-12 months. RESULTS: Poorer sensorimotor function was associated with falls (incidence rate ratio [95% CI], 1.46 [1.28-1.66]). Impaired executive function was the strongest predictor of falls overall (2.91 [2.27-3.73]), followed by depressive symptoms (2.07 [1.56-2.75]) and concern about falling (2.02 [1.61-2.55]). Associations were similar among groups, except for a weaker relationship with executive impairment in NI persons and a stronger relationship with concern about falling in persons with MS. Multivariable analyses showed that executive impairment, poorer sensorimotor performance, depressive symptoms, and concern about falling were independently associated with falls. CONCLUSIONS: Deficits in cognition (executive function) and affect (depressive symptoms) and concern about falling are as important as sensorimotor function for fall prediction. These domains should be included in fall risk assessments for older people and clinical groups.
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Accidentes por Caídas/estadística & datos numéricos , Disfunción Cognitiva/fisiopatología , Trastornos del Humor/fisiopatología , Esclerosis Múltiple/fisiopatología , Enfermedad de Parkinson/fisiopatología , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Factores de Riesgo , Encuestas y CuestionariosRESUMEN
OBJECTIVE: This study evaluated the relationship between physiological and perceived fall risk in people with multiple sclerosis (MS). DESIGN: Secondary analysis of data from prospective cohort studies undertaken in Australia, the United Kingdom, and the United States. SETTING: Community. PARTICIPANTS: Ambulatory people with MS (N=416) (age 51.5±12.0 years; 73% female; 62% relapsing-remitting MS; 13.7±9.9 years disease duration). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: All participants completed measures of physiological (Physiological Profile Assessment [PPA]) and perceived (Falls Efficacy Scale-international [FESi]) fall risk and prospectively recorded falls for 3 months. RESULTS: 155 (37%) of the participants were recurrent fallers (≥2 falls). Mean PPA and FESi scores were high (PPA 2.14±1.87, FESi 34.27±11.18). The PPA and the FESi independently predicted faller classification in logistic regression, which indicated that the odds of being classified as a recurrent faller significantly increased with increasing scores (PPA odds ratio [OR] 1.30 [95% CI 1.17-1.46], FESi OR 1.05 [95% CI 1.03-1.07]). Classification and regression tree analysis divided the sample into four groups based on cutoff values for the PPA: (1) low physiological/low perceived risk (PPA <2.83, FESi <27.5), (2) low physiological/high perceived risk (PPA <2.83, FESi >27.5), (3) high physiological/low perceived risk (PPA >2.83, FESi <35.5), and (4) high physiological/high perceived risk (PPA <2.83, FESi >35.5). Over 50% of participants had a disparity between perceived and physiological fall risk; most were in group 2. It is possible that physiological risk factors not detected by the PPA may also be influential. CONCLUSIONS: This study highlights the importance of considering both physiological and perceived fall risk in MS and the need for further research to explore the complex interrelationships of perceptual and physiological risk factors in this population. This study also supports the importance of developing behavioral and physical interventions that can be tailored to the individual's needs.
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Accidentes por Caídas/estadística & datos numéricos , Esclerosis Múltiple/fisiopatología , Esclerosis Múltiple/psicología , Adulto , Anciano , Australia/epidemiología , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Percepción , Estudios Prospectivos , Medición de Riesgo , Factores de Riesgo , Reino Unido/epidemiología , Estados Unidos/epidemiologíaRESUMEN
NEW FINDINGS: What is the central question of this study? Between 60 and 80% of multiple sclerosis (MS) patients experience transient worsening of symptoms with increased body temperature (heat sensitivity). As sensory abnormalities are common in MS, we asked whether afferent thermosensory function is altered in MS following exercise-induced increases in body temperature. What is the main finding and its importance? Increases in body temperature of as little as â¼0.4°C were sufficient to decrease cold, but not warm, skin thermosensitivity (â¼10%) in MS, across a wider temperature range than in age-matched healthy individuals. These findings provide new evidence on the impact of heat sensitivity on afferent function in MS, which could be useful for clinical evaluation of this neurological disease. In multiple sclerosis (MS), increases in body temperature result in transient worsening of clinical symptoms (heat sensitivity or Uhthoff's phenomenon). Although the impact of heat sensitivity on efferent physiological function has been investigated, the effects of heat stress on afferent sensory function in MS are unknown. Hence, we quantified afferent thermosensory function in MS following exercise-induced increases in body temperature with a new quantitative sensory test. Eight relapsing-remitting MS patients (three men and five women; 51.4 ± 9.1 years of age; Expanded Disability Status Scale score 2.8 ± 1.1) and eight age-matched control (CTR) subjects (five men and three women; 47.4 ± 9.1 years of age) rated the perceived magnitude of two cold (26 and 22°C) and two warm stimuli (34 and 38°C) applied to the dorsum of the hand before and after 30 min cycling in the heat (30°C air; 30% relative humidity). Exercise produced similar increases in mean body temperature in MS [+0.39°C (95% CI: +0.21, +0.53) P = 0.001] and CTR subjects [+0.41°C (95% CI: +0.25, +0.58) P = 0.001]. These changes were sufficient to decrease thermosensitivity significantly to all cold [26°C stimulus, -9.1% (95% CI: -17.0, -1.5), P = 0.006; 22°C stimulus, -10.6% (95% CI: -17.3, -3.7), P = 0.027], but not warm, stimuli in MS. Contrariwise, CTR subjects showed sensitivity reductions to colder stimuli only [22°C stimulus, -9.7% (95% CI: -16.4, -3.1), P = 0.011]. The observation that reductions in thermal sensitivity in MS were confined to the myelinated cold-sensitive pathway and extended across a wider (including milder and colder) temperature range than what is observed in CTR subjects provides new evidence on the impact of rising body temperature on afferent neural function in MS. Also, our findings support the use of our new approach to investigate afferent sensory function in MS during heat stress.
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Ejercicio Físico/fisiología , Esclerosis Múltiple/fisiopatología , Neuronas Aferentes/fisiología , Temperatura Cutánea/fisiología , Frío , Femenino , Mano/fisiología , Trastornos de Estrés por Calor/fisiopatología , Calor , Humanos , Masculino , Persona de Mediana Edad , Sensación/fisiología , Piel/fisiopatologíaRESUMEN
BACKGROUND: Stepping impairments increase fall risk in people with MS. No studies have evaluated step training for reducing fall risk in this population. OBJECTIVES: To determine if step training can improve physical and neuropsychological measures associated with falls in MS. METHODS: 50 PwMS with moderate disability participated in a randomized controlled trial in which intervention group participants (n = 28) performed step training for 12 weeks while controls (n = 22) continued usual physical activity. The primary outcomes were choice stepping reaction time (CSRT) and Stroop stepping test (SST) time. Secondary outcomes included balance test (postural sway, CSRT components), gait speed and cognitive tests, nine-hole peg test (9-HPT) and MS functional composite (MSFC) score. RESULTS: 44 participants completed the study and no adverse events were reported. Compared with the control group, the intervention group performed significantly better at retest in CSRT and SST times, and tests of sway with eyes open, 9-HPT, single and dual task gait speed and MSFC score. There was a non-significant trend for fewer falls in the intervention group. CONCLUSIONS: The findings indicate that the step training programme is feasible, safe and effective in improving stepping, standing balance, coordination and functional performance in people with MS.
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Función Ejecutiva/fisiología , Terapia por Ejercicio/métodos , Trastornos Neurológicos de la Marcha/rehabilitación , Esclerosis Múltiple/rehabilitación , Evaluación de Resultado en la Atención de Salud , Equilibrio Postural/fisiología , Desempeño Psicomotor/fisiología , Adulto , Prueba de Esfuerzo , Estudios de Factibilidad , Femenino , Trastornos Neurológicos de la Marcha/etiología , Humanos , Masculino , Persona de Mediana Edad , Esclerosis Múltiple/complicacionesRESUMEN
OBJECTIVES: To determine whether impaired performance in a range of vision, proprioception, neuropsychological, balance, and mobility tests and pain and fatigue are associated with falls in people with multiple sclerosis (PwMS). DESIGN: Prospective cohort study with 6-month follow-up. SETTING: A multiple sclerosis (MS) physiotherapy clinic. PARTICIPANTS: Community-dwelling people (N=210; age range, 21-74y) with MS (Disease Steps 0-5). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Incidence of falls during 6 months' follow-up. RESULTS: In the 6-month follow-up period, 83 participants (39.7%) experienced no falls, 57 (27.3%) fell once or twice, and 69 (33.0%) fell 3 or more times. Frequent falling (≥3) was associated with increased postural sway (eyes open and closed), poor leaning balance (as assessed with the coordinated stability task), slow choice stepping reaction time, reduced walking speed, reduced executive functioning (as assessed with the difference between Trail Making Test Part B and Trail Making Test Part A), reduced fine motor control (performance on the 9-Hole Peg Test [9-HPT]), and reported leg pain. Increased sway with the eyes closed, poor coordinated stability, and reduced performance in the 9-HPT were identified as variables that significantly and independently discriminated between frequent fallers and nonfrequent fallers (model χ(2)3=30.1, P<.001). The area under the receiver operating characteristic curve for this model was .712 (95% confidence interval, .638-.785). CONCLUSIONS: The study reveals important balance, coordination, and cognitive determinants of falls in PwMS. These should assist the development of effective strategies for prevention of falls in this high-risk group.
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Accidentes por Caídas/estadística & datos numéricos , Limitación de la Movilidad , Esclerosis Múltiple/epidemiología , Esclerosis Múltiple/fisiopatología , Equilibrio Postural , Adulto , Factores de Edad , Anciano , Fatiga/etiología , Fatiga/fisiopatología , Femenino , Estado de Salud , Humanos , Incidencia , Estilo de Vida , Masculino , Persona de Mediana Edad , Esclerosis Múltiple/complicaciones , Pruebas Neuropsicológicas , Dolor/etiología , Dolor/fisiopatología , Estudios Prospectivos , Índice de Severidad de la Enfermedad , Factores Socioeconómicos , Pruebas de VisiónRESUMEN
Silver nanoparticles (AgNPs) in the form of nanospheres from a few nm to 100 nm in diameter were synthesized in a controlled manner using a combination of two reducing agents: sodium borohydride (SBH) and trisodium citrate (TSC). The influence of the size of AgNPs on antibacterial activity was investigated with different concentrations of AgNPs on two types of bacteria:Pseudomonas aeruginosa(PA) andStaphylococcus aureusresistant (SA) while the positive control wasAmpicillin (Amp)50µg/ml and the negative control was water. AgNPs were investigated for morphology, size and size distribution using transmission electron microscopy (TEM) and dynamic light scattering (DLS) measurements. The optical properties of the AgNPs were investigated by recording their UV-vis absorption spectra. The antimicrobial activity of AgNPs was determined using the disc diffusion method. The results showed that the antibacterial ability of AgNPs depends on both concentration and particle size. With a particle concentration of 50µg ml-1, the antibacterial ability is the best. The smaller the particle size, the higher the antibacterial ability. The simultaneous use of two reducing agents TSC and SBH is the novelty of the article to synthesize AgNPs particles that are uniform in shape and size while controlling the particle size. On that basis, their antibacterial performance is increased.
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Borohidruros , Nanopartículas del Metal , Plata , Sustancias Reductoras , Escherichia coli , Antibacterianos/farmacologíaRESUMEN
INTRODUCTION: Alzheimer's disease (AD), the most prevalent neurodegenerative disorder globally, has emerged as a significant health concern. Recently it has been revealed that extracellular vesicles (EVs) play a critical role in AD pathogenesis and progression. Their stability and presence in various biofluids, such as blood, offer a minimally invasive window for monitoring AD-related changes. METHODS: We analyzed plasma EV-derived messenger RNA (mRNA) from 82 human subjects, including individuals with AD, mild cognitive impairment (MCI), and healthy controls. With next-generation sequencing, we profiled differentially expressed genes (DEGs), identifying those associated with AD. RESULTS: Based on DEGs identified in both the MCI and AD groups, a diagnostic model was established based on machine learning, demonstrating an average diagnostic accuracy of over 98% and showed a strong correlation with different AD stages. DISCUSSION: mRNA derived from plasma EVs shows significant promise as a non-invasive biomarker for the early detection and continuous monitoring of AD. Highlights: The study conducted next-generation sequencing (NGS) of mRNA derived from human plasma extracellular vesicles (EVs) to assess Alzheimer's disease (AD).Profiling of plasma EV-derived mRNA shows a significantly enriched AD pathway, indicating its potential for AD-related studies.The AD-prediction model achieved a receiver-operating characteristic area under the curve (ROC-AUC) of more than 0.98, with strong correlation to the established Clinical Dementia Rating (CDR).
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Cuprous oxide/copper/cupric oxide nanoparticles were synthesized through a hybrid process involving anodic dissolution and a controlled redox reaction between NaOH and glucose in the solution. The study demonstrates the structural manipulation of the material by varying the reaction components within the solution. Morphology, structural analyses using SEM (Scanning Electron Microscope), EDX (Energy-dispersive X-ray spectroscopy), TEM (Transmission Electron Microscope), FTIR (Fourier Transform Infrared Spectroscopy), XRD (X-ray diffraction), and XPS (X-ray photoelectron spectroscopy) unveiled the tunability of the material's structure based on the reaction components. Nitrogen adsorption analysis employing the Brunauer-Emmett-Teller (BET) equation confirmed the material's porosity, while Dynamic Light Scattering (DLS) measurements provided insights into the materials' hydrodynamic size and zeta potential. The results demonstrated that by increasing the glucose/NaOH ratio during the reaction, the different structures and morphologies of the distinct products were obtained from the clustering of small nanoparticles to cubic shape and flower-like structure. Antibacterial activity tests conducted on various bacterial strains showed a correlation between the morphology and structure of the material and its antibacterial properties. The highest substantial antibacterial efficacy against all tested bacterial strains at a dosage of 100 µg/L was obtained for the samples with clustering morphology, whereas the remaining materials showed no discernible antibacterial effect against one of the studied bacteria. The results also demonstrated that the sample with a clustering structure exhibited superior antibacterial properties when dispersed in water containing dimethylsulfoxide.
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OBJECTIVE: To evaluate psychometric properties of 16-item and 7-item Falls Efficacy Scale-International (FES-I) in people with multiple sclerosis (MS). DESIGN: Validation and prospective cohort study. SETTING: People with MS living in metropolitan areas. PARTICIPANTS: Community-dwelling people with MS (N=169; aged 21-73y) who were referred to Multiple Sclerosis Australia for physiotherapy assessment. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: FES-I scores and a range of sociodemographic, physical, and neuropsychological measures. RESULTS: The mean score for the 16-item FES-I was 34.9±11.2, and the mean score for the 7-item FES-I was 14.7±4.7. FES-I total scores were normally distributed: skewness of .35 (SEM=.19) for the 16-item and .47 (SEM .19) for the 7-item FES-I, indicating the absence of floor and ceiling effects. Internal reliability was excellent, with Cronbach's alpha values of .94 (16-item) and .86 (7-item). Rasch analyses indicated that the structure and measurement properties were better for the 7-item FES-I than for the 16-item FES-I. Construct validity of both scales was supported by sensitivity to group differences relating to demographic characteristics and fall-risk factors. CONCLUSIONS: The findings indicate that both 16-item and 7-item versions of the FES-I provide valuable information about the fear of falling in people with MS. However, the 7-item version of FES-I has better psychometric properties in people with MS.
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Accidentes por Caídas , Miedo/psicología , Esclerosis Múltiple/complicaciones , Esclerosis Múltiple/psicología , Encuestas y Cuestionarios , Actividades Cotidianas/psicología , Adulto , Anciano , Estudios Transversales , Análisis Factorial , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Psicometría , Autoeficacia , Adulto JovenRESUMEN
Previous studies have demonstrated the ability of osseointegration of porous titanium implants in cancellous bone. Our study was designed to (i) investigate the ability of bone ingrowth into 3D-printed porous titanium alloy implant on the cortical bone of rabbits using CT-scan and histology, and (ii) to identify the consistency of the radiology information between clinical Cone Beam Computed Tomography (CBCT) and Micro Computed Tomography (µCT) in the evaluation of bone ingrowth. The porous titanium alloy implants were 3D-printed employing the Electron Beam Melting (EBM) technology with an intended pore size of 600 µm and porosity of approximately 50 percent. Each implant was inserted into tibial diaphysis in one rabbit and its pores were classified as contacting bone or non-contacting bone. Depending on the time of explantation, the rabbits were divided into two groups: group 1 consisting of 6 rabbits between 13 and 20 weeks and group 2 consisting of 6 rabbits between 26 and 32 weeks. Tissue ingrowth into the non-bone contacting pores were evaluated by CBCT and histology. µCT was used to further investigate the bone ingrowth into four implants (two from each group were randomly chosen). The CBCT detected the present of tissue with bone-like density in both bone-contacting pores and non-bone-contacting pores of all implants. The µCT analysis also supported this result. All the bone-like tissues were then histologically confirmed to be mature bone. The analysis of CBCT data to assess bone ingrowth in porous implants had the sensitivity, specificity, positive and negative predictive values of 85, 84, 93 and 70 percent, respectively, when considering µCT assessment as the gold standard. Fully porous titanium alloy implant has great potential to reconstruct diaphyseal bone defect due to its good ability of osseointegration. CBCT is a promising method for evaluation of bone ingrowth into porous implants.
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Diáfisis , Lagomorpha , Animales , Conejos , Porosidad , Titanio , Microtomografía por Rayos X , Aleaciones , Impresión TridimensionalRESUMEN
BACKGROUND: This study examined the feasibility and efficacy of reactive balance training for improving stepping performance and reducing laboratory-induced falls in people with multiple sclerosis (MS). METHODS: Thirty people diagnosed with MS (18-70 years) participated in a blinded randomized controlled trial (ACTRN12618001436268). The intervention group (n = 14) underwent two 50-minute sessions (total 100 min) that exposed them to a total of 24 trips and 24 slips in mixed order, over one week. The control group (n = 16) received sham training (stepping over foam obstacles) with equivalent dosage. The primary outcome was falls into the harness (defined as >30% body weight) when exposed to trips and slips that were unpredictable in timing, location and type at post-assessment. Physical and psychological measures were also assessed at baseline and post assessments. RESULTS: The intervention and control groups completed 86% and 95% of the training protocols respectively. Incidence rate ratios (95% confidence intervals) of the intervention group relative to the control group were 0.57 (0.25, 1.26) for all falls, 0.80 (0.30, 2.11) for slip falls and 0.20 (0.04, 0.96) for trip falls in the laboratory. Kinematic analyses indicated the intervention participants improved dynamic stability, with higher centre of mass position and reduced trunk sway during recovery steps following a trip, compared to control. There were no significant differences between the intervention and control participants at post-assessment for other secondary outcome measures. CONCLUSIONS: Reactive balance training improved trip-induced dynamic stability, limb support, trunk control and reduced falls in people with MS. More research is required to optimise the training protocol and determine whether the beneficial effects of reactive balance training can be retained long term and generalize to fewer daily-life falls.
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Esclerosis Múltiple , Humanos , Esclerosis Múltiple/complicaciones , Esclerosis Múltiple/terapia , Equilibrio Postural , Marcha , Terapia por EjercicioRESUMEN
Locked thumb metacarpophalangeal (MCP) joint has been known as a relatively rare condition. We present a case of a 25-year-old male presented with a traumatic locked thumb MCP joint of the right hand. Clinical presentation showed the joint was in a hyperextention position and resistant to active flexion and extension. The radial sesamoid was distally displaced on X-ray film and entrapped into the joint on CT scan. The mechanism of the locked MCP joint was thought as a "pull-hook lock" between the pointed proximal edge of the sesamoid and the deformed volar groove on the cartilaginous surface of the metacarpal head. Surgical treatment included partially releasing the insertion of the abductor pollicis brevis (APB) and flexor pollicis brevis (FPB) muscles to move the entrapped radial sesamoid, and resurfacing the deformed metacarpal head.
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C21 steroidal glycosides are a group of natural compounds with biological activities such as anti-cancer, anti-microbial, and anti-viral properties. In this study, we isolated and determined the structure of a new C21 steroidal glycoside, named Marsdenialongise A from Marsdenia longipes W.T. Wang, using nuclear magnetic resonance spectroscopy and mass spectra data. Marsdenialongise A is a derivative of tenacigenin B and was isolated for the first time from a plant. The inhibitory effect of Marsdenialongise A on cancer cells was evaluated through MTT and cell migration assays, cell cycle, and apoptosis analyses. The results of the MTT assay showed that Marsdenialongise A reduces the cell viability of cancer cells, with the AGS cell line being more sensitive than other cell lines, with an IC50 value of 5.69 µM (for 48 h of treatment). Marsdenialongise A also exhibited an ability to prevent the migration of cancer cells in AGS cells. Further analysis using flow cytometry has revealed that Marsdenialongise A is capable of inducing cell cycle arrest and apoptosis. The overexpression of reactive oxygen species (ROS) production induced by Marsdenialongise A can be considered a cause that leads to the influence on the cell cycle and apoptosis of cancer cells. Thus, Marsdenialongise A can be considered a potential anti-cancer agent.
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Silver nanoparticles (C. AgNPs) are synthesized by the biological reduction method using extracts from green tea leaves (Camellia Sinensis) collected from tea hills at an altitude of 100 m above the ground. The chemicals present in the tea leaf extract act as reducing agents used to reduce Ag+ ions to silver atoms to form C. AgNPs in the solution. In this work, we optimized the C. AgNPs synthesis process by investigating the influence of reaction parameters such as concentration of tea leaf extract (1 ppm-50 ppm), reaction temperature (30 °C-60 °C), reaction time (5 min-100 min), and reaction rate (400 rpm-800 rpm) through absorption UV-Vis spectroscopy, TEM transmission electron microscopy, and spectroscopy X-ray. Organic compounds in tea leaf extract are detected by NMR measurement. The functional groups on the C. AgNPs are shown on the Fourier transform infrared (FTIR) spectrum. The C. AgNPs are used to degrade MB dye at 10 ppm concentration based on the photocatalytic effect using a 6500 K white light source. The C. AgNPs have also been studied for their antibacterial activity on two bacteria, Pseudomonas aeruginosa (P.A) and Staphylococcus aureus (S.A), while a positive control is Ampicillin 50 mg/ml and a negative control is H2O. The results reveal that the C. AgNPs with diameters in the range of 25 nm-55 nm degrade 10 ppm MB dye after 1 h with photodegradation efficiency up to 96 %. The antibacterial ability of C. AgNPs against both bacteria is good, even superior to that of Ampicillin. Furthermore, the particle synthesis efficiency and therefore the antibacterial activity as well as the photodegradation effect of C. AgNPs are higher than previously reported. At the same time, using green tea leaf extract to synthesize C. AgNPs creates environmentally friendly products. These useful behaviors are the potential to increase the scope and applicability of C. AgNPs, especially for biomedical applications in the near future.
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Biofilms are found in many infections in the forms of surface-adhering aggregates on medical devices, small clumps in tissues, or even in synovial fluid. Although antibiotic resistance genes are studied and monitored in the clinic, the structural and phenotypic changes that take place in biofilms can also lead to significant changes in how bacteria respond to antibiotics. Therefore, it is important to better understand the relationship between biofilm phenotypes and resistance and develop approaches that are compatible with clinical testing. Current methods for studying antimicrobial susceptibility are mostly planktonic or planar biofilm reactors. In this work, we develop a new type of biofilm reactor-three-dimensional (3D) microreactors-to recreate biofilms in a microenvironment that better mimics those in vivo where bacteria tend to form surface-independent biofilms in living tissues. The microreactors are formed on microplates, treated with antibiotics of 1000 times of the corresponding minimal inhibitory concentrations (1000 × MIC), and monitored spectroscopically with a microplate reader in a high-throughput manner. The hydrogels are dissolvable on demand without the need for manual scraping, thus enabling measurements of phenotypic changes. Bacteria inside the biofilm microreactors are found to survive exposure to 1000 × MIC of antibiotics, and subsequent comparison with plating results reveals no antibiotic resistance-associated phenotypes. The presented microreactor offers an attractive platform to study the tolerance and antibiotic resistance of surface-independent biofilms such as those found in tissues.
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INTRODUCTION: In this study we compared passive mechanical properties of gastrocnemius muscle-tendon units, muscle fascicles, and tendons in control subjects and people with ankle contractures after spinal cord injury. METHODS: Passive gastrocnemius length-tension curves were derived from passive ankle torque-angle data obtained from 20 spinal cord injured subjects with ankle contractures and 30 control subjects. Ultrasound images of muscle fascicles were used to partition length-tension curves into fascicular and tendinous components. RESULTS: Spinal cord injured subjects had stiffer gastrocnemius muscle-tendon units (stiffness index: 74.8 ± 27.0 m(-1) ) than control subjects (54.4 ± 17.7 m(-1) ) (P = 0.004). Muscle-tendon slack lengths, as well as slack lengths and changes in length of fascicles and tendons, were similar in the two groups. CONCLUSIONS: People with ankle contractures after spinal cord injury have stiff gastrocnemius muscle-tendon units. It is not clear whether this reflects changes in properties of muscle fascicles or tendons.
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Contracción Muscular/fisiología , Músculo Esquelético/fisiopatología , Traumatismos de la Médula Espinal/fisiopatología , Tendones/fisiopatología , Adulto , Anciano , Fenómenos Biomecánicos/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Músculo Esquelético/diagnóstico por imagen , Rango del Movimiento Articular/fisiología , Traumatismos de la Médula Espinal/diagnóstico por imagen , Estrés Mecánico , Tendones/diagnóstico por imagen , UltrasonografíaRESUMEN
OBJECTIVE: To investigate the mechanisms of contracture after stroke by comparing passive mechanical properties of gastrocnemius muscle-tendon units, muscle fascicles, and tendons in people with ankle contracture after stroke with control participants. DESIGN: Cross-sectional study. SETTING: Laboratory in a research institution. PARTICIPANTS: A convenience sample of people with ankle contracture after stroke (n=20) and able-bodied control subjects (n=30). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Stiffness and lengths of gastrocnemius muscle-tendon units, lengths of muscle fascicles, and tendons at specific tensions. RESULTS: At a tension of 100N, the gastrocnemius muscle-tendon unit was significantly shorter in participants with stroke (mean, 436mm) than in able-bodied control participants (mean, 444mm; difference, 8mm; 95% confidence interval [CI], 0.2-15mm; P=.04). Muscle fascicles were also shorter in the stroke group (mean, 44mm) than in the control group (mean, 50mm; difference, 6mm; 95% CI, 1-12mm; P=.03). There were no significant differences between groups in the mean stiffness or length of the muscle-tendon units and fascicles at low tension, or in the mean length of the tendons at any tension. CONCLUSIONS: People with ankle contracture after stroke have shorter gastrocnemius muscle-tendon units and muscle fascicles than control participants at high tension. This difference is not apparent at low tension.
Asunto(s)
Articulación del Tobillo/fisiopatología , Contractura/diagnóstico por imagen , Músculo Esquelético , Estrés Mecánico , Rehabilitación de Accidente Cerebrovascular , Anciano , Anciano de 80 o más Años , Articulación del Tobillo/diagnóstico por imagen , Fenómenos Biomecánicos , Contractura/etiología , Contractura/fisiopatología , Estudios Transversales , Femenino , Estudios de Seguimiento , Humanos , Funciones de Verosimilitud , Modelos Lineales , Masculino , Persona de Mediana Edad , Contracción Muscular/fisiología , Fibras Musculares Esqueléticas/diagnóstico por imagen , Valores de Referencia , Índice de Severidad de la Enfermedad , Accidente Cerebrovascular/complicaciones , Torque , Ultrasonografía DopplerRESUMEN
OBJECTIVES: Multiple sclerosis (MS), the most common chronic and progressive neurological condition of the central nervous system, affects 26,000 Australian adults. Exercise training has beneficial effects on MS-related impairments including reduced muscular strength, poor aerobic capacity and impaired mobility, and in consequence can improve quality of life. This Position Statement provides evidence-based recommendations for exercise prescription and delivery of exercise training for people with MS with mild to moderate disability. DESIGN AND METHODS: Synthesis of published works within the field of exercise training in MS. RESULTS: Exercise provides many benefits to people with MS. There is strong evidence that resistance and aerobic training, performed 2 to 3 times per week at a moderate intensity, are safe and can improve muscle strength, cardiorespiratory fitness, balance, fatigue, functional capacity, mobility and quality of life in people with MS with mild to moderate disability (Expanded Disease Severity Scale (EDSS)â¯≤â¯6.5). However, the evidence for those with severe disability (EDSS >6.5) is less clear. The effects of exercise on MS pathogenesis, central nervous structures and other outcomes such as depression and cognitive impairment, have not been adequately investigated. Effective exercise interventions to improve balance, joint contractures and reduce falls in people with MS are also urgently needed as well as investigations of long-term (≥1â¯year) effects of exercise training. CONCLUSIONS: Resistance and aerobic training exercises are effective to alleviate some characteristic signs and symptoms in MS and should be supplemented by balance exercise to prevent falls. Exercise training programs should be prescribed and delivered by qualified exercise professionals. It is important to recognise and accommodate exercise-associated complications such as fatigue and heat sensitivity.