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BACKGROUND: Sarcopenia and frailty are often used interchangeably in clinical practice yet represent two distinct conditions and require different therapeutic approaches. The literature regarding the co-occurrence of both conditions in older patients is scarce as most studies have investigated the prevalence of sarcopenia and frailty separately. OBJECTIVES: We aim to evaluate the prevalence and co-occurrence of sarcopenia and frailty in a large sample of acutely admitted older medical patients. DESIGN: Secondary analyses using cross-sectional data from the Copenhagen PROTECT study. SETTING: Patients were included from the acute medical ward at Copenhagen University Hospital, Bispebjerg and Frederiksberg, Copenhagen, Denmark, between November 2019 and November 2021. PARTICIPANTS: Acutely admitted older medical patients (≥65 years). MEASUREMENTS: Handgrip strength (HGS) was investigated using a handheld dynamometer. Lean mass (SMI) was investigated using direct-segmental multifrequency bioelectrical impedance analyses (DSM-BIA). Low HGS, low SMI, and sarcopenia were defined according to the recent definitions from the European Working Group on Sarcopenia in Older People (EWGSOP2). The Clinical Frailty Scale (CFS) was used to evaluate frailty, with a value > 5 indicating the presence of frailty. Patients were enrolled and tested within 24 hours of admission. RESULTS: This study included 638 patients (mean age: 78.2±7.6, 55% female) with complete records of SMI, HGS, and the CFS. The prevalence of low HGS, low SMI, sarcopenia, and frailty were 39.0%, 33.1%, 19.7%, and 39.0%, respectively. Sarcopenia and frailty co-occurred in 12.1% of the patients. CONCLUSIONS: It is well-known that sarcopenia and frailty represent clinical manifestations of ageing and overlap in terms of the impairment in physical function observed in both conditions. Our results demonstrate that sarcopenia and frailty do not necessarily co-occur within the older acutely admitted patient, highlighting the need for separate assessments of frailty and sarcopenia to ensure the accurate characterization of the health status of older patients.
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Fragilidad , Sarcopenia , Humanos , Femenino , Anciano , Anciano de 80 o más Años , Masculino , Sarcopenia/diagnóstico , Sarcopenia/epidemiología , Estudios Transversales , Fragilidad/diagnóstico , Fragilidad/epidemiología , Fuerza de la Mano , HospitalizaciónRESUMEN
BACKGROUND/OBJECTIVES: CAN-THUMBS UP is designed as a comprehensive and innovative fully remote program to 1) develop an interactive and compelling online Brain Health Support Program intervention, with potential to positively influence dementia literacy, self-efficacy and lifestyle risk factors; 2) enroll and retain a community-dwelling Platform Trial Cohort of individuals at risk of dementia who will participate in the intervention; 3) support an open platform trial to test a variety of multidomain interventions that might further benefit individuals at risk of dementia. This manuscript presents the Brain Health Support Program Study protocol. DESIGN/SETTING: Twelve-month prospective multi-center longitudinal study to evaluate a fully remote web-based educational intervention. Participants will subsequently be part of a Platform Trial Cohort and may be eligible to participate in further dementia prevention clinical trials. PARTICIPANTS: Three hundred fifty older adults who are cognitively unimpaired or have mild cognitive impairment, with at least 1 well established dementia risk factor. INTERVENTION: Participants engage in the Brain Health Support Program intervention for 45-weeks and complete pre/post intervention measures. This intervention is designed to convey best available evidence for dementia prevention, consists of 181 chapters within 8 modules that are progressively delivered, and is available online in English and French. The program has been developed as a collaborative effort by investigators with recognized expertise in the program's content areas, along with input from older-adult citizen advisors. MEASUREMENTS: This study utilizes adapted remote assessments with accessible technologies (e.g. videoconferencing, cognitive testing via computer and mobile phone, wearable devices to track physical activity and sleep, self-administered saliva sample collection). The primary outcome is change in dementia literacy, as measured by the Alzheimer's Disease Knowledge Scale. Secondary outcomes include change in self-efficacy; engagement using the online program; user satisfaction ratings; and evaluation of usability and acceptance. Exploratory outcomes include changes in attitudes toward dementia, modifiable risk factors, performance on the Neuropsychological Test Battery, performance on self-administered online cognitive assessments, and levels of physical activity and sleep; success of the national recruitment plan; and the distribution of age adjusted polygenic hazard scores. CONCLUSIONS: This fully remote study provides an accessible approach to research with all study activities being completed in the participants' home environment. This approach may reduce barriers to participation, provide an easier and less demanding participant experience, and reach a broader geography with recruitment from all regions of Canada. CAN-THUMBS UP represents a Canadian contribution to the global World-Wide FINGERS program (alz.org/wwfingers).
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Enfermedad de Alzheimer , Encéfalo , Anciano , Humanos , Canadá , Estudios Longitudinales , Estudios ProspectivosRESUMEN
Induced pluripotent stem cells (iPSCs) were generated from peripheral blood-derived erythroid progenitor cells obtained from a presymptomatic female carrying the heterozygous R418X progranulin (GRN) nonsense mutation, known to cause autosomal dominant frontotemporal lobar degeneration. Erythroid progenitor cells were reprogrammed into iPSCs using integration free episomal plasmids which enables exogenous expression of the Yamanaka factors. The pluripotent potential of the iPSCs was validated through expression of pluripotency factors and their capacity to differentiate into the three primary germ layers. The cells were confirmed to carry the described mutation and shown to have a normal karyotype.
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Diferenciación Celular , Codón sin Sentido , Fibroblastos/patología , Degeneración Lobar Frontotemporal/genética , Degeneración Lobar Frontotemporal/patología , Células Madre Pluripotentes Inducidas/patología , Progranulinas/genética , Células Cultivadas , Femenino , Fibroblastos/metabolismo , Heterocigoto , Humanos , Células Madre Pluripotentes Inducidas/metabolismoRESUMEN
A thorough understanding of the well-functioning, native aortic root is pivotal in an era, where valve sparing surgical techniques are developed and used with increasing frequency. The objective of this study was to characterize the local structural stiffness of the native aortic root, to create a baseline for understanding how different surgical interventions affect the dynamics of the aortic root. In this acute porcine study (Nâ¯=â¯10), two dedicated force transducers were implanted to quantify the forces acting on both the annular plane and on the sinotubular junction (STJ). To assess the changes in geometry, eleven sonomicrometry crystals were implanted within the aortic root. The combination of force and length measurements yields the radial structural stiffness for each segment of the aortic root. The least compliant segment at the annular plane was the right-left interleaflet triangle with a stiffness modulus of 1.1â¯Nâ¯mm-1 (SD0.4). At the sinotubular junction the same segment (right-left) was most compliant, compared with the two other segments, however not statistically significant different. The elastic energy storage was derived from the aortic root pressure volume relationship; the mean elastic energy storage was 826⯵J (SD529). In conclusion, the aortic root has been characterized in terms of both segmental forces, segmental change in length and elastic energy storage. This study is the first to assess the radial structural stiffness of different segments of the aortic root. The presented data is reference for further studies regarding the impact of surgical interventions on the aortic root.
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Aorta/fisiología , Válvula Aórtica/fisiología , Animales , Aorta/cirugía , Válvula Aórtica/cirugía , Fenómenos Biomecánicos , Femenino , Presión , PorcinosRESUMEN
In recent years the use of valve sparing techniques has become more common in selected patients with aortic valve insufficiency. However, limited experimental research has been performed to document the biomechanical effect of these techniques. One experimental platform is to evaluate how the normal physiological aortic root forces are altered or re-established after the surgical intervention. Hence, the aim of this project was to develop new implantable force transducers for a biomechanical description of various aortic root repair techniques. Two novel force transducers were developed. Both transducers were manufactured using rapid prototyping and were instrumented with miniature strain gauges. Before implantation both transducers were calibrated using a dedicated setup, yielding very linear correlation between the applied load and transducer output. The developed force transducers were implanted and tested in an 80kg porcine model. In the post-cardioplegic heart, the peak annular forces varied in the range of 2-4N and the commissural forces varied from 0.4 to 0.8N with a left ventricular pressure of 111mmHg. In conclusion, the two new force transducers to measure forces in the aortic root have successfully been developed. With these new devices a novel versatile and direct force measurement system has been provided.
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Válvula Aórtica , Ensayo de Materiales/instrumentación , Fenómenos Mecánicos , Transductores , Animales , Fenómenos Biomecánicos , Humanos , Prótesis e Implantes , PorcinosRESUMEN
Determination of muscle fiber composition in human skeletal muscle biopsies is often performed using immunohistochemistry, a method that tends to be both time consuming, technically challenging, and complicated by limited availability of tissue. Here, we introduce quantitative reverse transcriptase polymerase chain reaction (qRT-PCR)-based Gene-family profiling (GeneFam) of myosin heavy chain (MyHC) mRNA expression as a high-throughput, sensitive, and reliable alternative. We show that GeneFam and immunohistochemistry result in similar disclosures of alterations in muscle fiber composition in biopsies from musculus vastus lateralis and musculus biceps brachii of previously untrained young women after 12 weeks of progressive strength training. The adaptations were evident as (a) consistent increases in MyHC2A abundance; (b) consistent decreases in MyHC2X abundance; and (c) consistently stable MyHC1 abundance, and were not found using traditional reference gene-based qRT-PCR analyses. Furthermore, muscle fiber composition found using each of the two approaches was correlated with each other (r = 0.50, 0.74, and 0.78 for MyHC1, A, and X, respectively), suggesting that GeneFam may be suitable for ranking of individual muscle phenotype, particularly for MyHC2 fibers. In summary, GeneFam of MyHC mRNA resulted in reliable assessment of alterations in muscle fiber composition in skeletal muscle of previously untrained women after 12 weeks of strength training.
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Acondicionamiento Físico Humano/fisiología , Músculo Cuádriceps/química , ARN Mensajero/análisis , Entrenamiento de Fuerza , Adulto , Femenino , Perfilación de la Expresión Génica , Humanos , Inmunohistoquímica , Cadenas Pesadas de Miosina/genética , Fenotipo , Músculo Cuádriceps/citología , Reacción en Cadena en Tiempo Real de la Polimerasa , Adulto JovenRESUMEN
PURPOSE: To investigate the effects of strength training on abundances of irisin-related biomarkers in skeletal muscle and blood of untrained young women, and their associations with body mass composition, muscle phenotype and levels of thyroid hormones. METHODS: Eighteen untrained women performed 12 weeks of progressive whole-body heavy strength training, with measurement of strength, body composition, expression of irisin-related genes (FNDC5 and PGC1α) in two different skeletal muscles, and levels of serum-irisin and -thyroid hormones, before and after the training intervention. RESULTS: The strength training intervention did not result in changes in serum-irisin or muscle FNDC5 expression, despite considerable effects on strength, lean body mass (LBM) and skeletal muscle phenotype. Our data indicate that training affects irisin biology in a LBM-dependent manner. However, no association was found between steady-state serum-irisin or training-associated changes in serum-irisin and alterations in body composition. FNDC5 expression was higher in m.Biceps brachii than in m.Vastus lateralis, with individual expression levels being closely correlated, suggesting a systemic mode of transcriptional regulation. In pre-biopsies, FNDC5 expression was correlated with proportions of aerobic muscle fibers, a relationship that disappeared in post-biopsies. No association was found between serum-thyroid hormones and FNDC5 expression or serum-irisin. CONCLUSION: No evidence was found for an effect of strength training on irisin biology in untrained women, though indications were found for a complex interrelationship between irisin, body mass composition and muscle phenotype. FNDC5 expression was closely associated with muscle fiber composition in untrained muscle.
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Peso Corporal , Fibronectinas/metabolismo , Músculo Esquelético/metabolismo , Entrenamiento de Fuerza , Adulto , Femenino , Fibronectinas/sangre , Fibronectinas/genética , Humanos , Músculo Esquelético/fisiología , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma , Fenotipo , Hormonas Tiroideas/sangre , Factores de Transcripción/sangre , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
The purpose of this study was to compare the effects of two different methods of organizing endurance training in trained cyclists during a 12-week preparation period. One group of cyclists performed block periodization (BP; n = 8), wherein every fourth week constituted five sessions of high-intensity aerobic training (HIT), followed by 3 weeks of one HIT session. Another group performed a more traditional organization (TRAD; n = 7), with 12 weeks of two weekly HIT sessions. The HIT was interspersed with low-intensity training (LIT) so that similar total volumes of both HIT and LIT were performed in the two groups. BP achieved a larger relative improvement in VO2max than TRAD (8.8 ± 5.9% vs 3.7 ± 2.9%, respectively, < 0.05) and a tendency toward larger increase in power output at 2 mmol/L [la(-)] (22 ± 14% vs 10 ± 7%, respectively, P = 0.054). Mean effect size (ES) of the relative improvement in VO2max , power output at 2 mmol/L [la(-)], hemoglobin mass, and mean power output during 40-min all-out trial revealed moderate superior effects of BP compared with TRAD training (ES range was 0.62-1.12). The present study suggests that BP of endurance training has superior effects on several endurance and performance indices compared with TRAD.
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Rendimiento Atlético/fisiología , Ciclismo/fisiología , Acondicionamiento Físico Humano/métodos , Acondicionamiento Físico Humano/fisiología , Adulto , Hemoglobinas/metabolismo , Humanos , Masculino , Fuerza Muscular/fisiología , Consumo de Oxígeno/fisiología , Resistencia Física/fisiología , Factores de TiempoRESUMEN
The aquaculture industry needs a simple, inexpensive and safe method for the treatment of fish waste without heat. Microbial inactivation by inorganic acid (HCl) or base (KOH) was determined using infectious pancreatic necrosis virus (IPNV) as a model organism for fish pathogens. Salmonella and spores of Clostridium perfringens were general hygiene indicators in supplementary examinations. IPNV, which is considered to be among the most chemical- and heat-resistant fish pathogens, was reduced by more than 3 log in 4 h at pH 1.0 and pH 12.0. Salmonella was rapidly inactivated by the same treatment, whereas spores of C. perfringens were hardly affected. The results indicate that low and high pH treatment could be particularly suitable for fish waste destined for biogas production. pH treatment at aquaculture production sites could reduce the spread of fish pathogens during storage and transportation without disturbing the anaerobic digestion process. The treatment could also be an alternative to the current energy-intensive steam pressure sterilization of fish waste to be used by the bioenergy, fertilizer and soil improver industries.
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Acuicultura/métodos , Productos Pesqueros/virología , Ácido Clorhídrico/farmacología , Virus de la Necrosis Pancreática Infecciosa/efectos de los fármacos , Hidróxido de Sodio/farmacología , Inactivación de Virus/efectos de los fármacos , Acuicultura/economía , Clostridium perfringens/efectos de los fármacos , Clostridium perfringens/fisiología , Productos Pesqueros/microbiología , Concentración de Iones de Hidrógeno , Virus de la Necrosis Pancreática Infecciosa/fisiología , Viabilidad Microbiana/efectos de los fármacos , Salmonella enterica/efectos de los fármacos , Salmonella enterica/fisiología , Esporas Bacterianas/efectos de los fármacos , Esporas Bacterianas/fisiologíaRESUMEN
BACKGROUND: Attention towards optimization of mitral valve repair methods is increasing. Patch augmentation is one strategy utilized to correct functional mitral regurgitation or systolic anterior motion in complex mitral valve repairs. This article describes a system for investigating the redistribution of chordae tendineae tension as a reflection of altered stress distribution of the valve leaflet following patch augmentation. METHODS AND MATERIALS: An in vitro test setup was constructed to hold native porcine mitral valves containing an annulus and papillary muscle positioning system. The alterations caused by patch augmentation should be visual from both the atrial and ventricular views. Ventricular pressure was regulated stepwise in a range of 0-150 mmHg. To test the system, the anterior mitral leaflet was extended by a pericardial patch sutured to the mid/basal part of the leaflet, and the chordae tendineae force was measured as the ventricular pressure was applied. RESULTS: The system demonstrated the capacity to hold native porcine mitral valves and introducing patch repairs according to clinical practice. The porcine mitral valve test setup indicated strong correlation between the forces in the mitral valve secondary chordae tendineae and the applied transvalvular pressure (R2 = 0.95). CONCLUSION: This test setup proved the ability to obtain normal mid-systolic mitral valve function, secondary chordae force measurements, and important preservation of the visual access: Hence, obtaining the pressure-force relationship as well as identifying any shift of the secondary chordae insertion point on the anterior leaflet relative to the coaptation zone was made possible.
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How blood flow and pressure to the giraffe's brain are regulated when drinking remains debated. We measured simultaneous blood flow, pressure, and cross-sectional area in the carotid artery and jugular vein of five anesthetized and spontaneously breathing giraffes. The giraffes were suspended in the upright position so that we could lower the head. In the upright position, mean arterial pressure (MAP) was 193 +/- 11 mmHg (mean +/- SE), carotid flow was 0.7 +/- 0.2 l/min, and carotid cross-sectional area was 0.85 +/- 0.04 cm(2). Central venous pressure (CVP) was 4 +/- 2 mmHg, jugular flow was 0.7 +/- 0.2 l/min, and jugular cross-sectional area was 0.14 +/- 0.04 cm(2) (n = 4). Carotid arterial and jugular venous pressures at head level were 118 +/- 9 and -7 +/- 4 mmHg, respectively. When the head was lowered, MAP decreased to 131 +/- 13 mmHg, while carotid cross-sectional area and flow remained unchanged. Cardiac output was reduced by 30%, CVP decreased to -1 +/- 2 mmHg (P < 0.01), and jugular flow ceased as the jugular cross-sectional area increased to 3.2 +/- 0.6 cm(2) (P < 0.01), corresponding to accumulation of approximately 1.2 l of blood in the veins. When the head was raised, the jugular veins collapsed and blood was returned to the central circulation, and CVP and cardiac output were restored. The results demonstrate that in the upright-positioned, anesthetized giraffe cerebral blood flow is governed by arterial pressure without support of a siphon mechanism and that when the head is lowered, blood accumulates in the vein, affecting MAP.
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Anestesia General , Presión Sanguínea , Circulación Cerebrovascular , Movimientos de la Cabeza , Venas Yugulares/fisiología , Postura , Rumiantes/fisiología , Animales , Gasto Cardíaco , Arterias Carótidas/diagnóstico por imagen , Arterias Carótidas/fisiología , Presión Venosa Central , Gravitación , Venas Yugulares/diagnóstico por imagen , Masculino , Flujo Sanguíneo Regional , Telemetría , Ultrasonografía DopplerRESUMEN
Patients undergoing open-heart surgery may, post-operatively, suffer from neurological disorders due to microbubbles created during extracorporeal circulation. Venous air is not completely removed in open hard-shell venous reservoirs. We, therefore, investigated the relationship between venous reservoir blood level and the amount of microbubbles in different commercially available reservoirs for comparison and determination of safe level. An in vitro flow loop with a heart-lung machine was used to compare three different reservoirs (Maquet, Sorin and Medtronic) at different levels. Microbubbles were measured after the reservoir and after the arterial filter with a GAMPT BCC200 detector. Microbubble count and volume were significantly higher with decreasing reservoir level (p = 0.014), but not as much as earlier studies have shown. Reducing the level from 1000 ml to 250 ml resulted in a 12.4% increase in bubble volume after the reservoir and 40.2% after the arterial filter. There was an almost linear trend towards more bubble volume with decreasing reservoir level (R2 = 0.98-0.83). There was a significant difference in microbubbles between the 3 tested reservoirs, up to 32.6%, p < 0.001 measured after the reservoir. Bubble volume from the Sorin reservoir was markedly lower after the arterial filter than from the Medtronic and Maquet reservoirs (up to 60 times p < 0.001). A lower reservoir level results in a moderate rise in microbubbles passing the reservoir. The minimum levels recommended by the manufacturers are safe. There was a significant difference in bubbles between the different reservoirs, especially after the arterial filter.
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Puente Cardiopulmonar/instrumentación , Catéteres de Permanencia , Embolia Aérea/etiología , Circulación Extracorporea/instrumentación , Circulación Extracorporea/métodos , Microburbujas/efectos adversos , Máquina Corazón-Pulmón , HumanosRESUMEN
BACKGROUND: The objective of this study was to examine the association between self-rated health (SRH) and physical, functional, social and mental health measures in community dwelling elderly people needing nursing care. Of special interest was how coping resources (SOC) influenced this relationship. Self-rated health is a good predictor of future health status as measured by mortality and morbidity, decline of functional abilities, use of healthcare, and nursing home placement. The high mean age and the relatively high level of care-dependency in this sample, make this investigation important. METHODS: A hierarchical regression analysis was applied in a cross sectional sample of 242 elderly (mean age 84.6 years). RESULTS: Subjective health complaints (SHC) in both sexes, and psychological distress (only in men), was associated directly with SRH. Coping resources associated with SRH directly, and indirectly through subjective perceived health (SHC and GHQ) but only in men. The influence of registered illness was mediated through the effects of subjectively perceived health in both women and men. Sex differences moderated the effects of SOC on SRH. CONCLUSION: Subjectively perceived health was more important in the perception of SRH than objective health measures. Men, in contrast to women, tend to convert physical illness into emotional distress.
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Anciano Frágil/estadística & datos numéricos , Estado de Salud , Características de la Residencia , Encuestas y Cuestionarios , Adaptación Psicológica , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Casas de Salud/estadística & datos numéricosRESUMEN
Emboli monitoring is nowadays based on the assessment of microembolic signals by Doppler ultrasound. However, the present systems have problems in detecting multiple emboli. A more dedicated algorithm for post-processing of the recorded Doppler signals was proposed. Based on the hypothesis that single and multiple gaseous emboli can be quantified by combining discrete and continuous wavelet transformation, the aim of this study was to detect gaseous emboli and to validate our method visually. A flow rig was used where gaseous emboli were generated. Doppler signals and visual validation data of gaseous emboli were acquired simultaneously. Microembolic signals were extracted and analysed using wavelet transformation. Results were validated against a visual reference. At various degrees of bubble generation, the system had 100 per cent detection during a low frequency of bubble generation but an estimation error of 7.4 per cent during a high frequency of bubble generation. The estimation error varied between -7.4 and +3 per cent. The system had a higher rate of success in detecting large gaseous emboli in small numbers than small gaseous emboli in large numbers. Single and double emboli were successfully detected and separated, whereas gaseous emboli clouds could be detected but not quantified. Being able to separate simultaneous gaseous emboli may offer new means of increasing detectability for embolism monitoring.
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Algoritmos , Embolia Aérea/diagnóstico por imagen , Embolia Aérea/fisiopatología , Interpretación de Imagen Asistida por Computador/métodos , Reología/métodos , Ultrasonografía/métodos , Humanos , Interpretación de Imagen Asistida por Computador/instrumentación , Fantasmas de Imagen , Reproducibilidad de los Resultados , Reología/instrumentación , Sensibilidad y EspecificidadRESUMEN
BACKGROUND: Among elderly people without dementia, the apolipoprotein E epsilon4 allele (APOE4) has been associated with cognitive deficit, particularly in episodic memory, but few reports are available on whether this association differs by sex. METHODS: In a community-dwelling Norwegian cohort of 2181 elderly people (55% women), aged 70-74 years, episodic memory was examined in relation to sex and APOE4 zygosity, with the Kendrick Object Learning Test (KOLT). RESULTS: Possession of at least one APOE4 allele had a modest, detrimental effect on episodic memory in women, whereas in men, heterozygotes were unaffected and homozygotes had markedly lower scores across the distribution of KOLT scores. This sex difference was found consistently in all analyses: on comparing means and medians, examining trends across quintiles, and studying the distribution of scores and the risk of cognitive impairment. Results were broadly similar when adjusted for known determinants of cognition and also when severely impaired participants were excluded. The adjusted odds ratio (OR) of cognitive impairment in women was shown to be 1.8 (95% confidence interval (CI): 1.1 to 2.8) for heterozygotes and 1.1 (0.3 to 3.7) for homozygotes; the adjusted OR in men was observed to be 1.1 (0.6 to 2.1) for heterozygotes and 10.7 (4.7 to 24) for homozygotes. CONCLUSIONS: Although the harmful effect of APOE4 on episodic memory was modest in women, the risk was found to occur in about 30%. APOE4 was observed to have a dramatic effect on episodic memory in men, but only in homozygotes, who comprised about 3% of men: the whole male homozygous group showed a marked shift to lower memory scores.
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Apolipoproteínas E/genética , Trastornos de la Memoria/genética , Anciano , Alelos , Enfermedad de Alzheimer , Apolipoproteína E4 , Trastornos del Conocimiento/genética , Estudios de Cohortes , Femenino , Genotipo , Humanos , Masculino , Oportunidad Relativa , Periodicidad , Factores SexualesRESUMEN
Heart rate variability (HRV) analysis from 10s ECGs has been shown to be reliable. However, the short examination time warrants a user-friendly system that can be used for ad-hoc examinations without normal preparation, unlike ECG. A handheld device has been developed that can measure ultra-short HRV from impedance plethysmographic recordings of the pulse wave in distal superficial arteries. The prototype device was made user-friendly through a compact, pen-like design and the use of integrated metal electrodes that were especially designed for dry operation. The main signal processing was performed by a digital signal processor, where the discrete heart beats were detected using a correlation algorithm that could adapt to individual pulse wave shapes to account for biological variation. The novel device was evaluated in 20 mainly young volunteers, using 10 s time-correlated ECG recordings as the reference method. Agreement between the two methods in measuring heart rate and root mean square of successive differences in the heart beat interval (RMSSD) was analysed using correlation coefficients (Pearson's R2), mean differences with 95% confidence intervals and 95% limits of agreement, and Bland-Altman plots. The correlation between the two methods was R2 = 1.00 and R2 = 0.99 when heart rate and RMSSD were measured, respectively. The Bland-Altman plots showed suitable agreement between the novel device and standard 10 s ECGs, which was substantiated by 95% limits of agreement of the difference of +/- 0.1 beats min(-1) and approximately +/- 10 ms for heart rate and RMSSD, respectively. Therefore the evaluation showed no significant systematic error of the novel device compared with ECG.
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Frecuencia Cardíaca , Pletismografía de Impedancia/instrumentación , Adulto , Electrocardiografía , Electrónica Médica , Diseño de Equipo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pletismografía de Impedancia/métodos , Procesamiento de Señales Asistido por ComputadorRESUMEN
This study introduced the Kalman filter procedure for tracking urinary bladder filling from intermittent bladder volume measurements taken by an ultrasonic bladder volume monitor. The Kalman filter was based on a double integrator as a model for the bladder filling process between micturitions and included a procedure to reset the filter in the event of a micturition. The performance of the Kalman filter was evaluated experimentally using an ultrasonic bladder volume monitor on seven male urologic patients. During cystometry, saline was infused into the patient's bladder at a constant rate of 30 ml min(-1) until it was full, and the volume of the bladder was recorded every 30 s by the bladder volume monitor. The evaluation showed that the filter significantly improved the precision of the measured volumes in terms of mean absolute errorby 4.2 ml (95% confidence interval: 0.7-7.7 ml) (p = 0.025) without affecting the system accuracy, i.e. slope (p= 0.92) and intercept (p= 0.32). Finally, the micturition reset procedure was verified using simulated data.
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Procesamiento de Señales Asistido por Computador , Vejiga Urinaria/diagnóstico por imagen , Vejiga Urinaria/fisiología , Humanos , Masculino , Ultrasonografía , Micción/fisiología , UrodinámicaRESUMEN
Ultrasonic bladder volume monitors have successfully been used in the diagnosis and treatment of various urological disorders. Ultrasonic bladder monitors have been developed but they have either been too bulky or too simple and inaccurate. A new, wearable ultrasonic bladder volume monitor has been designed for urological patients. The instrument consists of seven phased-array ultrasonic transducers ergonomically arranged in a circular pattern to optimise detection of the bladder walls perpendicular to the abdominal wall. A Bluetooth radio link was used to transmit data to a laptop computer, where the main signal processing was performed. After detection of bladder surface points, a three-dimensional convex hull representing the bladder was generated, and the volume was estimated. Accuracy, precision, drift over time, temperature dependency and dynamic performance were evaluated using ultrasound phantoms. Furthermore, the system was tested on one volunteer using magnetic resonance imaging (MRI) as reference. The apparatus showed no significant drift, systematic error or temperature effects. Percentage error during static volume measurements had a 95% central prediction interval of +/-7.5% and mean absolute percentage error of 2.9%. The dynamic performance analysis showed linearity in the analysed volume interval. The in vivo study showed a high degree of correlation (R2= 0.99) between the volume measured using MRI and that measured with the apparatus.
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Ultrasonido , Vejiga Urinaria/fisiopatología , Enfermedades Urológicas/fisiopatología , Diagnóstico por Computador/métodos , Diseño de Equipo , Ergonomía , Humanos , Imagen por Resonancia Magnética/métodos , Microcomputadores , Monitoreo Fisiológico/instrumentación , Fantasmas de Imagen , Transductores , Enfermedades Urológicas/diagnósticoRESUMEN
Methods for measuring the T-wave dispersion are difficult to improve, because the exact result is unknown. This study describes a flexible and cheap method for analysing the measurement problems. The analysis consisted of measuring the T-wave dispersion of electrocardiograms and vector loops with simulated dispersion. The vector loops were simulated using two primary T-waves that were identical, quasi-monophasic and located in orthogonal leads. The dispersion was the time delay between the primary T-waves. The electrocardiograms were projections of the vector loops on approximations to the orientations of leads in the standard 12-lead ECG. This simulation model was validated by matching simulated ECGs and vector loops with measured ECGs and vector loops drawn from a population of 247 patients with acute myocardial infarction. The analysis of the measurement problems was demonstrated by measuring an approximation to the classical QT-dispersion in ECGs with simulated dispersion in the interval 0-100 ms, in steps of 2 ms. This showed that the QT-dispersion was unable to measure the simulated dispersion accurately in the clinically relevant interval of 50-100 ms. The results indicated that the low prognostic accuracy of the QT-dispersion could be due to an inaccurate measurement method.
Asunto(s)
Simulación por Computador , Electrocardiografía , Infarto del Miocardio/fisiopatología , Anciano , Interpretación Estadística de Datos , Humanos , Persona de Mediana EdadRESUMEN
AIM: Based on a multidisciplinary review of drug use in nursing home residents, this study aimed to identify the most frequent clinically relevant medication problems and to analyse them according to the drugs involved and types of problems. METHODS: Cross sectional study auditing drug use by 1354 residents in 23 nursing homes in Bergen, Norway. Data were collected in 1997. A physician/pharmacist panel performed a comprehensive medication review with regard to indications for drug use and active medical conditions. The drug related problems were subsequently classified according to the drugs involved and types of problems (indication, effectiveness, and safety issues). RESULTS: 2445 potential medication problems were identified in 1036 (76%) residents. Psychoactive drugs accounted for 38% of all problems; antipsychotics were the class most often involved. Multiple psychoactive drug use was considered particularly problematic. Potential medication problems were most frequently classified as risk of adverse drug reactions (26%), inappropriate drug choice for indication (20%), and underuse of beneficial treatment (13%). CONCLUSIONS: Three of four nursing home residents had clinically relevant medication problems, most of which were accounted for by psychoactive drugs. The most frequent concerns were related to adverse drug reactions, drug choice, and probable undertreatment.