RESUMEN
BACKGROUND: Manual wheelchairs are an important mobility device for hemiplegic stroke patients, but understandably difficult to operate. A novel mobility device termed the functional electrical stimulation-assisted leg-propelled wheelchair (FES-LW) was proposed and a field test conducted to evaluate its clinical performance by comparison against a manual wheelchair (MW). METHODS: A total of 20 hemiplegic patients were recruited from the National Cheng Kung University Hospital. They were instructed to successively propel the FES-LW and MW comfortably, as fast as possible, in along an oval pathway. The finish time, deviation frequencies, deviation percentage, physiological cost index (PCI), and modified Ashworth scale (MAS) of affected ankle were measured and compared. FINDINGS: Subjects can propel the FES-LW with 40.1% less finish time (P=0.003); 23.7% lower deviation frequencies (P=0.009) and 36.7% lower deviation percentage (P=0.001); and 17.7% lower PCI (P=0.022) than the MW. In addition, the MAS of the affected ankle was noticeably reduced (P=0.002) after propelling the FES-LW. INTERPRETATION: The FES-LW showed better controllability, cardiopulmonary response and positive effects on reducing spasticity versus the MW. The FES-LW is a suitable alternative to a MW for the needs of hemiplegic stroke patients.
Asunto(s)
Terapia por Estimulación Eléctrica/métodos , Hemiplejía/fisiopatología , Hemiplejía/rehabilitación , Pierna/fisiopatología , Locomoción , Análisis y Desempeño de Tareas , Silla de Ruedas , Adulto , Anciano , Femenino , Humanos , Pierna/inervación , Masculino , Persona de Mediana Edad , Resultado del TratamientoRESUMEN
This paper presents a capillary electrophoresis poly(methyl methacrylate) (PMMA) based microchip for electrochemical detection applications featuring embedded gold nanoelectrode ensemble (GNEE) working and decoupler electrodes. In fabricating the microchip, the GNEE films are pressed directly onto the metallic electrode structures using a hot embossing technique, and the microfluidic channels are then sealed using a low-temperature azeotropic solvent bonding method. The detection performance of the microchip is evaluated using dopamine and catechol analytes for illustration purposes. The experimental results show that the GNEE working electrode provides a significantly higher signal response than that obtained from a bulk gold electrode when applied to the detection of dopamine analyte. Compared to a conventional bulk palladium decoupler electrode, the GNEE decoupler electrode reduces both the amplitude of the charge current (3.5 nA vs. 18.7 nA) and the baseline drift at higher separation voltages. The measured baseline current drift for the microchip equipped the proposed GNEE decoupler electrode is around three times smaller than the microchip with the palladium decoupler electrode under the applied separation electric field from 40 V/cm to 240 V/cm. Finally, when detecting a mixture of 1mM dopamine and 1mM catechol, the calculated signal response of the microchip with a GNEE decoupler electrode is approximately five times higher than that obtained from a microchip with a bulk Pd decoupler electrode, resulting in the detection limit of 1 microM for the proposed GNEE-based microchip device. Overall, the results indicate that the proposed capillary electrophoresis-electrochemical detection (CE-ED) microchip with embedded GNEE working and decoupler electrodes provides an ideal solution for sample detection in lab-on-a-chip and micro total analysis applications.
Asunto(s)
Electroforesis Capilar/instrumentación , Electroforesis Capilar/métodos , Oro/química , Microelectrodos , Catecoles/análisis , Dopamina/análisis , Electroquímica , Polimetil Metacrilato , Reproducibilidad de los ResultadosRESUMEN
It has been suggested that fruit and vegetable consumption are associated with good bone health. Onion, in particular, has been verified in its efficacy in bone resorption activity. In this study, we further investigated the effects of an onion-containing diet on ovariectomy-induced bone loss using methods of serum marker assay, histomorphometric analysis and biomechanical tests. Sixty-four female Wistar rats (14-week-old) with sham operations or ovariectomy were assigned to 6 groups: CON, sham-operated control group; OVX, ovariectomized group; ALN, ovariectomized rats treated with alendronate (1 mg/kg/day, p.o.); and 3% ON, 7% ON and 14% ON, ovariectomized rats fed with diets containing 3%, 7% and 14% (wt/wt) onion powder, respectively. Animals were sacrificed after a six-week treatment course. In the serum marker assay, alendronate and all three onion-enriched diets significantly decreased serum calcium level (p<0.05). Both 14% ON group and the ALN group even showed similarly lower level of serum osteocalcin (p<0.05), suggesting a down-regulation of bone turnover. The histomorphometric analysis showed that ovariectomy markedly decrease bone trabeculae. The ALN and 14% ON rats were 80% and 46% higher, respectively, in BV/TV than the OVX rats (p<0.05), and the rats fed with onion-enriched food showed a lesser ovariectomy-induced bone loss in a dose-dependent manner. Additionally, both ALN and 14% ON groups had significantly more trabecular number, less separated trabeculae, and fewer osteoclasts (p<0.05), but the protective efficacy from the 14% onion-enriched diet was slightly inferior to that of alendronate. Ovariectomy also significantly decreased tissue weight and biomechanical strength in the OVX group (p<0.05). The ALN and 14% ON groups equivalently showed a lesser decrease in tissue weight, though the difference was not significant. On the other hand, both the ALN and 14% ON groups represented similar biomaterial properties of femurs, and both reduced the ovariectomy-induced decrease in bending load and bending energy (p<0.05). The present study further verified that an onion-enriched diet could counteract ovariectomy-induced bone loss and deterioration of biomechanical properties.
Asunto(s)
Conservadores de la Densidad Ósea/farmacología , Enfermedades Óseas Metabólicas , Huesos/efectos de los fármacos , Dieta , Cebollas/química , Ovariectomía , Extractos Vegetales/farmacología , Alendronato/farmacología , Animales , Biomarcadores/sangre , Huesos/anatomía & histología , Huesos/fisiología , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Masculino , Ratas , Ratas WistarRESUMEN
This paper presents a novel method regarding a wavelength-resolved fluorescence detection scheme for high-throughput analysis of bio-samples in a micro-CE chip. Instead of using the conventional laser-induced fluorescence (LIF) microscope equipped with delicate spatial filters and complex control systems, this study adopts a hollow cone illumination generated using a dark-field condenser for exciting fluorescence in the microchannel and an ultraviolet-visible-near-infrared (UV-Vis-NIR) spectrometer for detecting the emission signals. Experimental results show that the proposed system is feasible for simultaneously detecting a mixed sample composed of Atto 610, Rhodamine B and fluorescein isothiocyanate (FITC) fluorescent dyes in a single test run. Furthermore, a mixed bio-sample composed of two mixed 16-mer single-stranded DNAs labeled with Cy3 and FITC fluorescent dyes is also successfully detected with the proposed system. The measured limit of detection (LOD) for detecting FITC of the proposed system can be as low as 5.4x10(-6)M (S/N=3). This proposed detection method has shown its potential on RNA identification and DNA sequencing applications.
Asunto(s)
Electroforesis Capilar/métodos , Espectrometría de Fluorescencia/instrumentación , Electroforesis Capilar/instrumentación , Técnicas Analíticas Microfluídicas/instrumentaciónRESUMEN
Two methods have been used to produce a maximal voluntary isometric contraction (MVIC) of the superficial quadriceps femoris muscles for normalization of electromyographic (EMG) data. The purposes of this study were to compare the myoelectic activity of MVIC of manual muscle testing (MMT) versus Cybex maximal isometric testing. Eighteen normal subjects were recruited. MMT and Cybex testing for MVIC of the dominant leg were performed. EMG activities of the vastus medialis, vastus lateralis and rectus femoris were recorded during MMT and Cybex trials. EMG amplitude and median frequency obtained from the two methods (MMT and Cybex testing) were used for statistical analysis of these three muscles. Statistically, the difference in the mean of the EMG signal amplitude and median frequency between MMT and Cybex testing were not significant. Considering cost and time, MMT for MVIC technique appears to be reliable and highly valuable.
Asunto(s)
Electromiografía/métodos , Contracción Isométrica/fisiología , Músculo Cuádriceps/fisiología , Adulto , HumanosRESUMEN
End-range mobilization techniques are recommended for the treatment of patients with hypomobile joints. The purposes of this study were (1) to assess the reliability of a glenohumeral (GH) stiffness measurement technique and (2) apply the measurement technique on subjects with adhesive capsulitis to compare the GH end-range stiffness and rotational range of motions (ROMs) before and immediately after the application of end-range translational mobilization techniques. Fifteen normal subjects were recruited for assessment of test-retest reliability. Four men and two women with adhesive capsulitis in the glenohumeral joint (mean disease duration=6.5 months, SD=2.7) were treated with end-range mobilization by an experienced physical therapist. The passive abduction angles, rotational ROM and GH joint stiffness were measured by the same observer before and immediately after end-range mobilization treatment. The test-retest reliability was assessed and revealed good to excellent reliability in anterior-posterior glenohumeral joint stiffness and fair to excellent reliability of GH stiffness in posterior-anterior direction. The GH joint stiffness decreased and passive abduction range of motion increased immediately after end-range mobilization of the shoulder joint. The use of intensive mobilization techniques may help to decrease the risk of further stiffness or joint contracture progression in patients with adhesive capsulitis.
Asunto(s)
Bursitis/fisiopatología , Bursitis/terapia , Modalidades de Fisioterapia , Articulación del Hombro , Adulto , Femenino , Humanos , Masculino , Rango del Movimiento Articular , Reproducibilidad de los ResultadosRESUMEN
BACKGROUND AND PURPOSE: The resting position is frequently used by clinicians in the examination and early treatment of patients with joint impairments. However, there is a lack of research on the kinematic characteristics of the resting position of the glenohumeral (GH) joint. The aim of this study was to define the resting position of the GH joint by quantifying the humeral head translation and axial rotational range of motion (ROM). SUBJECTS AND METHODS: The anterior and posterior translation of the humeral head and the rotational ROM of the dominant arm were assessed in the seated position at multiple abduction positions in 15 subjects who were healthy by use of an electromagnetic tracking device. A force of 80 N and a torque of 4 N.m were applied during the measurement procedures for the translation of the humeral head and the rotational ROM, respectively. RESULTS: The mean resting position determined by rotational movement was located at 49.8 degrees of GH abduction. However, the mean resting position determined by translational movement was located at 23.7 degrees of GH abduction and was significantly lower than the resting position determined by rotational movement (t=5.45, P=.000). DISCUSSION AND CONCLUSION: The mean resting position for rotational movement is consistent with the already accepted range of 30 to 60 degrees for a "loosely packed" position of the GH joint. The mean resting position for translational movement appears to be lower than 30 to 60 degrees. The results of this study suggest that, at least for the GH joint, different resting positions should be assessed with different movement criteria (accessory or physiological movement).
Asunto(s)
Húmero/fisiología , Postura/fisiología , Rango del Movimiento Articular/fisiología , Descanso/fisiología , Articulación del Hombro/fisiología , Adulto , Análisis de Varianza , Femenino , Humanos , Masculino , RotaciónRESUMEN
BACKGROUND AND PURPOSE: Joint mobilization is a complicated task to learn and to teach and is characterized by great intersubject variability. This study's purpose was to investigate whether quantitatively augmented feedback could enhance the learning of joint mobilization and, more specifically, to compare the effects of training with concurrent or terminal feedback by using a joint translation simulator (JTS). SUBJECTS: Thirty-six undergraduate physical therapist students were randomly assigned to control (no feedback), concurrent feedback, and terminal feedback groups. METHODS: The JTS was designed to simulate tissue resistance based on load-displacement relationships of glenohumeral joint specimens. Subjects applied specific mobilization grades of force on the JTS while quantitative feedback was given to the feedback groups either during a trial (ie, concurrent feedback) or after a trial (ie, terminal feedback). The skill acquisition phase lasted a total of 40 minutes, and a total of 75 repetitions were performed for each grade of each joint model. Pretest and no-feedback retention tests were conducted. RESULTS: During acquisition and retention, both feedback groups performed more accurately than did the control group. No obviously superior performance was shown by the terminal feedback group compared with concurrent feedback group during retention testing. DISCUSSION AND CONCLUSION: Subjects who trained with augmented feedback had less variability, and thus more consistency, than the control group subjects who received no feedback. Augmented feedback provides the student with a reference force and the status of his or her performance. The effectiveness of the JTS feedback compared with no feedback was clearly demonstrated. Skill acquisition in mobilization can be enhanced by either concurrent or terminal feedback.
Asunto(s)
Retroalimentación , Articulaciones , Movimiento , Modalidades de Fisioterapia/educación , Adulto , Femenino , Humanos , Aprendizaje , Masculino , Manipulaciones Musculoesqueléticas/educación , Modalidades de Fisioterapia/instrumentaciónRESUMEN
This study uses simple and reliable microfabrication techniques to fabricate CE biochips, integrating a novel contactless conductivity detector in a miniaturized detection system in a microfluidic biochip. The off-channel electrodes are deposited around side channels by Au sputtering and patterned using a standard "lift-off" process. A vacuum fusion bonding process is employed to seal the lower substrate containing the microchannels and the electrodes to an upper glass cover plate. The variations in the capacitance between the semicircular detection electrodes in the side channels are measured as different samples and ions pass through the detection region of the CE separation channel. Samples of Rhodamine B, commercial sports drinks, mineral waters, and a red wine, respectively, are mixed in different buffer solutions, separated, and successfully detected using the developed device. The semicircular detection electrodes for the contactless conductivity detector have microscale dimensions and provide a valuable contribution to the realization of the lab-on-a-chip concept.
Asunto(s)
Electroforesis Capilar/instrumentación , Electroforesis por Microchip/instrumentación , Conductometría/métodos , Conductividad Eléctrica , Oro/química , Microelectrodos , Aguas Minerales/análisis , Rodaminas/análisis , Vino/análisisRESUMEN
Delayed treatment with nicotinamide (NAm) reduces infarction induced by middle cerebral artery occlusion (MCAO) in rats. This study explored some potential mechanisms by which delayed NAm treatment may confer protection in the brain of Sprague-Dawley rats following permanent MCAO (pMCAO). NAm (500 mg/kg) or vehicle was given 2 h after the onset of pMCAO. Cortical microperfusion, brain and rectal temperature were serially measured. Neurobehavioral examinations were performed at 24 h post-ischemia followed by sacrifice for histologic assessment. Some rats were also sacrificed at 4 h post-ischemia for analyses of ATP, ADP, AMP, and adenosine. Permanent MCAO induced spontaneous hyperthermia and a sharp decrease in cortical microperfusion, ATP concentration, and the sum of adenine nucleotides (p < 0.05). At 4 h post-ischemia, NAm improved ATP recovery, the sum of adenine nucleotides (p < 0.05) and attenuated the ischemia-induced systemic hyperthermia (p < 0.05) without affecting brain temperature or cortical microperfusion. At 24 h, NAm improved cortical microperfusion in the ischemic hemisphere and reduced total infarct volume (p < 0.05), but did not affect behavioral scores. The data suggest that NAm attenuated brain damage following pMCAo initially by improving cerebral bioenergetic metabolism during the sub-acute phase of ischemia, followed by a delayed improvement in microvascular perfusion.
Asunto(s)
Encéfalo/efectos de los fármacos , Circulación Cerebrovascular/efectos de los fármacos , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Fármacos Neuroprotectores/administración & dosificación , Niacinamida/administración & dosificación , Recuperación de la Función/efectos de los fármacos , Adenina/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Conducta Animal/efectos de los fármacos , Encéfalo/irrigación sanguínea , Encéfalo/metabolismo , Química Encefálica/efectos de los fármacos , Modelos Animales de Enfermedad , Fiebre/etiología , Infarto de la Arteria Cerebral Media/complicaciones , Infarto de la Arteria Cerebral Media/patología , Masculino , Ratas , Ratas Sprague-Dawley , Factores de TiempoRESUMEN
We have recently shown that melatonin decreases the late (24 hr) increase in blood-brain barrier (BBB) permeability and the risk of tissue plasminogen activator-induced hemorrhagic transformation following ischemic stroke in mice. In the study, we further explored whether melatonin would reduce postischemic neurovascular oxidative/nitrosative damage and, therefore, improve preservation of the early increase in the BBB permeability at 4 hr after transient focal cerebral ischemia for 60 min in mice. Melatonin (5 mg/kg) or vehicle was given intraperitoneally at the beginning of reperfusion. Hydroethidine (HEt) in situ detection and immunohistochemistry for nitrotyrosine were used to evaluate postischemic accumulation in reactive oxygen and nitrogen species, respectively, in the ischemic neurovascular unit. BBB permeability was evaluated by spectrophotometric and microscopic quantitation of Evans Blue leakage. Relative to controls, melatonin-treated animals not only had a significantly reduced superoxide accumulation in neurovascular units in boundary zones of infarction, by reducing 35% and 54% cytosolic oxidized HEt in intensity and cell-expressing percentage, respectively (P < 0.001), but also exhibited a reduction in nitrotyrosine by 52% (P < 0.01). Additionally, melatonin-treated animals had significantly reduced early postischemic disruption in the BBB permeability by 53% (P < 0.001). Thus, melatonin reduced postischemic oxidative/nitrosative damage to the ischemic neurovascular units and improved the preservation of BBB permeability at an early phase following transient focal cerebral ischemia in mice. The findings further highlight the ability of melatonin in anatomical and functional preservation for the ischemic neurovascular units and its relevant potential in the treatment of ischemic stroke.
Asunto(s)
Barrera Hematoencefálica/fisiopatología , Infarto de la Arteria Cerebral Media/fisiopatología , Ataque Isquémico Transitorio/fisiopatología , Melatonina/farmacología , Animales , Encéfalo/irrigación sanguínea , Azul de Evans/farmacocinética , Ataque Isquémico Transitorio/tratamiento farmacológico , Flujometría por Láser-Doppler , Masculino , Melatonina/administración & dosificación , Ratones , Ratones Endogámicos C57BL , Permeabilidad , Especies de Nitrógeno Reactivo/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Daño por Reperfusión/fisiopatologíaRESUMEN
BACKGROUND: We conducted biomechanical evaluation of the anterior plating and posterior wiring techniques for cervical spine stabilization after a course of healing in sheep. METHODS: Seventeen sheep were included, and six of which underwent sham operations (group A, n=6). The other eleven received complete C2-C3 destabilization, followed by intervertebral bone grafting and cervical stabilization either with anterior plating (group B, n=5) or posterior wiring (group C, n=6) techniques. These animals were killed 6 months later. Ligamentous spines (C1-C5) were subjected to the relevantly applied loads. The load-deformation data of the C2-C3 and C3-C4 functional units were recorded and analyzed. RESULTS: At the C2-C3 functional unit, group B had the least motion ranges in flexion, lateral bending, and rotation loads than did the other two groups. Significantly smaller motion ranges of lateral bending and rotation loads were found in group B than in group C (p<0.05). Compared with group A, group C had a decreased motion range in flexion load but showed increased motion range in rotation load. Consequently, group B had superior intervertebral fusion and less osteophyte than did group C. At the C3-C4 functional unit, group B showed significantly decreased motion ranges in extension and lateral bending loads (p<0.05), while group C did not. CONCLUSION: The results indicated that the anterior plate-stabilized spines were more stable over time than did the posterior-wired spines. This biomechanical advantage eventually resulted in superior intervertebral fusion masses in the former, although it also induced a slightly decreased motion range at the contiguous functional unit. In exclusively posterior wired-spines, the weakness for opposing rotation loads might contribute to the formation of osteophytes at the fusion functional unit. These data point out that the mode and stability of implant fixation systems greatly influence the biomechanical redistribution and bone-adaptive remodeling process during healing, which are closely related to the bone graft maturation and osteophytic formations at the fusion level and the occurrence of stiffening problems at the contiguous levels.
Asunto(s)
Placas Óseas , Hilos Ortopédicos , Vértebras Cervicales , Desplazamiento del Disco Intervertebral/cirugía , Fusión Vertebral/métodos , Animales , Fenómenos Biomecánicos , Desplazamiento del Disco Intervertebral/patología , Postura , Rango del Movimiento Articular , OvinosRESUMEN
Recent studies suggest that beta-amyloid (Abeta) aggregation and toxicity are facilitated by metal ions. This study aims to evaluate the kinetics of Abeta aggregation/dissociation in the presence of metal ions and to investigate the efficacy of a metal chelator to disrupt the metal ion-induced Abeta aggregates. Soluble Abeta(1-40) peptide was immobilized on a surface plasmon resonance biosensing surface and aggregation induced by contact with soluble Abeta with or without metal ions. Our study revealed that all the tested metal ions promoted Abeta aggregation but with different kinetics. Among them, Cu(II) ions had the highest association constant, and reached the maximum binding in 10 min. However, the Cu(II)-induced Abeta aggregates were unstable. Other ions attained the maximum Abeta binding at much longer times: 45 min for Ca(II), 60 min for Fe(II), Fe(III), and Zn(II) ions. The Abeta aggregates induced by Fe(III) ions had the greatest stability. The metal ion-induced Abeta(1-40) aggregates could be disrupted by the metal chelator, EDTA, suggesting a metal chelator may serve as a pharmacological agent to interfere with Abeta aggregation. Finally, this study demonstrates that the SPR biosensor can be an effective and efficient setup to investigate the mechanism of Abeta aggregation.
Asunto(s)
Péptidos beta-Amiloides/química , Metales/química , Algoritmos , Péptidos beta-Amiloides/inmunología , Anticuerpos/química , Reacciones Antígeno-Anticuerpo , Técnicas Biosensibles , Tampones (Química) , Quelantes , Ácido Edético , Cinética , Fosfatos/química , Cloruro de Sodio , Resonancia por Plasmón de Superficie , Propiedades de SuperficieRESUMEN
Using a total internal reflection fluorescence microscopy (TIRFM) technique to image live cells on a biosurface not only provides an enhanced understanding of cellular functions, but also improves the signal-to-noise ratio of the images. However, the intensity of the fluorescence signal must be increased if a more dynamic biomolecular imaging capability is required. Accordingly, this study presents a surface plasmon-enhanced TIRFM technique in which the fluorescence signals are enhanced via surface plasmons offered by a silver nanolayer. The developed microscopy technique is successfully applied to the real-time observation of the thrombomodulin proteins of live cell membranes. The experimental results and the simulation results demonstrate that the live cell membrane images obtained in the proposed surface plasmon-enhanced TIRFM technique are brighter by approximately one order of magnitude than those provided by conventional TIRFM.
RESUMEN
OBJECT: The authors examined whether delayed treatment with Mg++ would reduce brain infarction and improve electrophysiological and neurobehavioral recovery following cerebral ischemia-reperfusion. METHODS: Male Sprague-Dawley rats were subjected to right middle cerebral artery occlusion for 90 minutes followed by 72 hours of reperfusion. Magnesium sulfate (750 micromol/kg) or vehicle was given via intracarotid infusion at the beginning of reperfusion. Neurobehavioral outcome and somatosensory evoked potentials (SSEPs) were examined before and 72 hours after ischemia-reperfusion. Brain infarction was assessed after the rats had died. Before ischemia-reperfusion, stable SSEP waveforms were recorded after individual fore- and hindpaw stimulations. At 72 hours of perfusion the SSEPs recorded from ischemic fore- and hindpaw cortical fields were depressed in vehicle-injected animals and the amplitudes decreased to 19 and 27% of baseline, respectively (p < 0.001). Relative to controls, the amplitudes of SSEPs recorded from both ischemic fore- and hindpaw cortical field in the Mg++-treated animals were significantly improved by 23% (p < 0.005) and 39% (p < 0.001) of baselines, respectively. In addition, Mg++ improved sensory and motor neurobehavioral outcomes by 34% (p < 0.01) and 24% (p < 0.05), respectively, and reduced cortical (p < 0.05) and striatal (p < 0.05) infarct sizes by 42 and 36%, respectively. CONCLUSIONS: Administration of Mg++ at the commencement of reperfusion enhances electrophysiological and neurobehavioral recovery and reduces brain infarction after cerebral ischemia-reperfusion. Because Mg++ has already been used clinically, it may be worthwhile to investigate it further to see if it holds potential benefits for patients with ischemic stroke and for those who will undergo carotid endarterectomy.
Asunto(s)
Potenciales Evocados Somatosensoriales , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Ataque Isquémico Transitorio/tratamiento farmacológico , Magnesio/farmacología , Recuperación de la Función/efectos de los fármacos , Animales , Conducta Animal , Corteza Cerebral/patología , Corteza Cerebral/fisiopatología , Cuerpo Estriado/patología , Cuerpo Estriado/fisiopatología , Infarto de la Arteria Cerebral Media/patología , Infarto de la Arteria Cerebral Media/fisiopatología , Inyecciones Intraarteriales , Ataque Isquémico Transitorio/patología , Ataque Isquémico Transitorio/fisiopatología , Masculino , Ratas , Ratas Sprague-Dawley , Accidente Cerebrovascular/tratamiento farmacológico , Accidente Cerebrovascular/patología , Accidente Cerebrovascular/fisiopatología , Factores de TiempoRESUMEN
Acute neuroprotective effects of cinnamophilin (CINN; (8R, 8'S)-4, 4'-dihydroxy-3, 3'-dimethoxy-7-oxo-8, 8'-neolignan), a novel antioxidant and free radical scavenger, were studied in a mouse model of transient middle cerebral artery (MCA) occlusion. CINN was administered intraperitoneally either 15 min before (pretreatment) or 2 h after the onset of MCA occlusion (postischemic treatment). Relative to vehicle-treated controls, animals pretreated with CINN, at 20-80 mg/kg, had significant reductions in brain infarction by 33-46% and improvements in neurobehavioral outcome. Postischemic administration with CINN (80 mg/kg) also significantly reduced brain infarction by 43% and ameliorated neurobehavioral deficits. Additionally, CINN administration significantly attenuated in situ accumulation of superoxide anions (O2-) in the boundary zones of infarct at 4 h after reperfusion. Consequently, CINN-treated animals exhibited significantly decreased levels of oxidative damage, as assessed by immunopositive reactions for 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 4-hydroxynonenal (4-HNE), and the resultant inflammatory reactions at 24 h post-insult. It is concluded that CINN effectively reduced brain infarction and improved neurobehavioral outcome following a short-term recovery period after severe transient focal cerebral ischemia in mice. The finding of a decreased extent of reactive oxygen species and oxidative damage observed with CINN treatment highlights that its antioxidant and radical scavenging ability is contributory.
Asunto(s)
Antioxidantes/uso terapéutico , Isquemia Encefálica/prevención & control , Depuradores de Radicales Libres/uso terapéutico , Guayacol/análogos & derivados , Lignanos/uso terapéutico , Animales , Isquemia Encefálica/tratamiento farmacológico , Corteza Cerebral/irrigación sanguínea , Circulación Cerebrovascular/efectos de los fármacos , Guayacol/uso terapéutico , Infarto de la Arteria Cerebral Media/fisiopatología , Masculino , Ratones , Ratones Endogámicos C57BL , Estrés Oxidativo/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/antagonistas & inhibidores , Daño por Reperfusión/prevención & control , Factores de TiempoRESUMEN
We have previously shown that melatonin reduces infarct volumes and enhances neurobehavioral and electrophysiological recoveries following transient middle cerebral artery (MCA) occlusion in rats. In the study, we examined whether melatonin would display neuroprotection against neuronal, axonal and oligodendrocyte pathology after 24 hr of reperfusion following 1 hr of MCA occlusion in mice. Melatonin (5 mg/kg) or vehicle was given intraperitoneally at the commencement of reperfusion. Neurological deficits were assessed 24 hr after ischemia. Gray matter damage was evaluated by quantitative histopathology. Axonal damage was determined with amyloid precursor protein and microtubule-associated protein tau-1 immunohistochemistry to identify postischemic disrupted axonal flow and oligodendrocyte pathology, respectively. Oxidative damage was assessed by 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 4-hydroxynonenal (4-HNE) immunohistochemistry. Relative to controls, melatonin-treated animals not only had a significantly reduced volume of gray matter infarction by 42% (P<0.001), but also exhibited a decreased score of axonal damage by 42% (P<0.001) and a reduction in the volume of oligodendrocyte pathology by 58% (P<0.005). Melatonin-treated animals also had significantly reduced immunopositive reactions for 8-OHdG and 4-HNE by 53% (P<0.001) and 49% (P<0.001), respectively. In addition, melatonin improved sensory and motor neurobehavioral outcomes by 47 and 30%, respectively (P<0.01). Thus, delayed (1 hr) treatment with melatonin reduced both gray and white matter damage and improved neurobehavioral outcomes following transient focal cerebral ischemia in mice. The finding of reduced oxidative damage observed with melatonin suggests that its major mechanisms of action are mediated through its antioxidant and radical scavenging activity.
Asunto(s)
Isquemia Encefálica/prevención & control , Encéfalo/patología , Melatonina/farmacología , Animales , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patología , ADN/metabolismo , Hidroxilación , Peroxidación de Lípido , Masculino , Ratones , Ratones Endogámicos C57BL , Estrés OxidativoRESUMEN
OBJECTIVES: To evaluate the effects of anterior thermal capsulorrhaphy of the glenohumeral joint by monitoring changes of magnitudes of the anterior and posterior displacements of the humeral head and ranges of motion of abduction and rotation in fresh cadaver shoulders. DESIGN: Single session repeated-measures design. BACKGROUND: Following thermal shrinkage anterior and posterior displacements of the head of humerus were decreased. However, no studies were focused on the ranges of motion of abduction and rotation of the shoulder joint immediately. The mobility of abduction and rotation are also important indexes for glenohumeral function. METHODS AND MEASURES: Nine fresh frozen shoulder specimens were used. The dorsal and ventral displacements of humeral head and ranges of motion of abduction and rotation of glenohumeral joint before and after thermal capsulorrhaphy were performed and monitored. Changes after thermal treatment in these linear and angular displacement variables were calculated as outcome measures. RESULTS: After anterior thermal capsulorrhaphy, significant (P < 0.001) decreases were found in displacements (-1.80 mm in dorsal direction and -1.24 mm in ventral direction), rotation range of motion (-3.93 degrees in lateral rotation and -2.60 degrees in medial rotation), and abduction range of motion (-3.15 degrees ). CONCLUSIONS: The results from cadaveric experiments showed that anterior thermal capsulorrhaphy immediately reduced the dorsal and ventral displacements and ranges of abduction and rotation of glenohumeral joint by a small amount. RELEVANCE: Radiofrequency electrosurgical system combined with arthroscopy has the potential to decrease the translations of the humeral head as well as the rotational range of motion of the glenohumeral joint.
Asunto(s)
Ablación por Catéter/métodos , Cápsula Articular/cirugía , Inestabilidad de la Articulación/fisiopatología , Inestabilidad de la Articulación/cirugía , Rango del Movimiento Articular , Articulación del Hombro/fisiopatología , Articulación del Hombro/cirugía , Anciano , Anciano de 80 o más Años , Artroscopía/métodos , Cadáver , Elasticidad , Humanos , Hipertermia Inducida/métodos , Técnicas In Vitro , Cápsula Articular/fisiopatología , Persona de Mediana Edad , Movimiento , Recuperación de la Función , Torque , Resultado del Tratamiento , Soporte de PesoRESUMEN
Melatonin has been reported to reduce infarct volumes induced by transient middle cerebral artery (MCA) occlusion. We examined whether melatonin could improve electrophysiological and neurobehavioral recoveries in rats after 72 hr of reperfusion following 1.5 hr of MCA occlusion. Melatonin (5 mg/kg) or vehicle was given intravenously at the commencement of reperfusion. Neurobehavioral outcome was serially examined, and somatosensory evoked potentials (SSEP) were recorded prior to ischemia and at 72 hr after the onset of reperfusion. Brain infarction was assessed upon killing. Before ischemia-reperfusion, stable SSEP waveforms were consistently recorded after individual fore- or hindpaw stimulation. The amplitude between the first positive (P1) and the first negative (N1) peaks and the P1 latency did not differ significantly between controls and melatonin-treated animals. At 72 hr of reperfusion, controls had severely depressant SSEPs recorded from ischemic fore- and hindpaw cortical fields, and the amplitudes decreased to 36 and 35% of baselines, respectively (P < 0.001). These animals also had transcallosal electrophysiological diaschisis in the SSEPs recorded at the contralateral hindpaw cortical field (P < 0.01). Relative to controls, melatonin-treated animals not only had significantly improved amplitudes of the SSEPs recorded from both ischemic fore- and hindpaw cortical fields, by 33 and 37% of baselines, respectively (P < 0.001), but also exhibited diminished transcallosal electrophysiological diaschisis following ischemia-reperfusion. In addition, melatonin improved sensory and motor neurobehavioral outcomes by 40 and 28%, respectively (P < 0.001), and reduced cortical and striatal infarct sizes by 32 and 40%, respectively (P < 0.05). Thus, delayed intravenous administration with melatonin both enhances electrophysiological and neurobehavioral recoveries and reduces cortical and striatal infarct sizes after cerebral ischemia and reperfusion injury.
Asunto(s)
Ataque Isquémico Transitorio/tratamiento farmacológico , Melatonina/farmacología , Animales , Conducta Animal/efectos de los fármacos , Conducta Animal/fisiología , Peso Corporal/efectos de los fármacos , Corteza Cerebral/irrigación sanguínea , Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/patología , Circulación Cerebrovascular/efectos de los fármacos , Cuerpo Estriado/efectos de los fármacos , Cuerpo Estriado/patología , Electrofisiología/métodos , Potenciales Evocados Somatosensoriales/efectos de los fármacos , Infarto de la Arteria Cerebral Media/complicaciones , Inyecciones Intravenosas , Ataque Isquémico Transitorio/etiología , Ataque Isquémico Transitorio/fisiopatología , Masculino , Ratas , Ratas Sprague-Dawley , ReperfusiónRESUMEN
This paper presents an experimental and numerical investigation into the use of high-resolution injection techniques to separate DNA fragments within electrophoresis microchips. The study addresses the principal material transport mechanisms such as electrokinetic migration, fluid flow, diffusion, variable-volume injection methods, and gives detail analyses to the double-L injection technique, which employs electrokinetic manipulations to avoid sample leakage within the microchip. We also study the sample leakage effect during sample injection and separation. The standard DNA ladder and the phi/-174 DNA fragments are used to test the performance for this proposed method. Results show that this unique injection system in the current microfluidic chip presented within this paper is capable of simulating the functions of the cross, double-T form through appropriate manipulations of the electric field within its various channels. The proposed double-L injection method confirms its ability to reduce sample leakage effect during operation. The integrated microfluidic chip and double-L injection technique developed in this study has an exciting potential for use in high-quality, high-throughput chemical analysis applications and in many other applications throughout the field of micro-total-analysis systems.