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1.
Osteoarthritis Cartilage ; 30(6): 852-861, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35331859

RESUMEN

OBJECTIVES: We previously reported, based on a multicenter randomized-control study, that the efficacy of intra-articular injections of hyaluronic acid (IA-HA) was not inferior to that of oral non-steroidal anti-inflammatory drugs (NSAIDs) in patients with knee osteoarthritis (OA). However, the molecular effects on the pathophysiology of knee OA remain unclear. C-terminal telopeptides of type II collagen (CTX-II) is reported to primarily originate from the interface between articular cartilage and subchondral bone, which is a site of potential remodeling in OA. We performed a predefined sub-analysis of the previous study to compare the changes of urinary CTX-II (uCTX-II) in response to IA-HA to those in response to NSAID for knee OA. DESIGN: A total of 200 knee OA patients were registered from 20 hospitals and randomized to receive IA-HA (2,700 kDa HA, 5 times at 1-week intervals) or NSAID (loxoprofen sodium, 180 mg/day) for 5 weeks. The uCTX-II levels were measured before and after treatment. RESULTS: The uCTX-II levels were significantly increased by IA-HA treatment (337.7 ± 193.8 to 370.7 ± 234.8 ng/µmol Cr) and were significantly reduced by NSAID treatment (423.2 ± 257.6 to 370.3 ± 250.9 ng/µmol Cr). The %changes of uCTX-II induced by IA-HA (11.6 ± 29.5%) and NSAID (-9.0 ± 26.7%) was significantly different (between-group difference: 20.6, 95% confidence intervals: 10.6 to 30.6). CONCLUSIONS: While both IA-HA and NSAID improved symptoms of knee OA, uCTX-II levels were increased by IA-HA and reduced by NSAIDs treatment, suggesting these treatments may improve symptoms of knee OA through different modes of action.


Asunto(s)
Osteoartritis de la Rodilla , Antiinflamatorios no Esteroideos/uso terapéutico , Biomarcadores , Colágeno Tipo II , Humanos , Ácido Hialurónico/uso terapéutico , Inyecciones Intraarticulares , Peso Molecular , Resultado del Tratamiento , Viscosuplementos/uso terapéutico
2.
J Dent Res ; 100(10): 1161-1168, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34315313

RESUMEN

Osseointegration of dental, craniofacial, and orthopedic implants is critical for their long-term success. Multifunctional surface treatment of implants was found to significantly improve cell adhesion and induce osteogenic differentiation of dental-derived stem cells in vitro. Moreover, local and sustained release of antibiotics via nanolayers from the surface of implants can present unparalleled therapeutic benefits in implant dentistry. Here, we present a layer-by-layer surface treatment of titanium implants capable of incorporating BMP-2-mimicking short peptides and gentamicin to improve their osseointegration and antibacterial features. Additionally, instead of conventional surface treatments, we employed polydopamine coating before layer-by-layer assembly to initiate the formation of the nanolayers on rough titanium surfaces. Cytocompatibility analysis demonstrated that modifying the titanium implant surface with layer-by-layer assembly did not have adverse effects on cellular viability. The implemented nanoscale coating provided sustained release of osteoinductive peptides with an antibacterial drug. The surface-functionalized implants showed successful osteogenic differentiation of periodontal ligament stem cells and antimicrobial activity in vitro and increased osseointegration in a rodent animal model 4 wk postsurgery as compared with untreated implants. Altogether, our in vitro and in vivo studies suggest that this approach can be extended to other dental and orthopedic implants since this surface functionalization showed improved osseointegration and an enhanced success rate.


Asunto(s)
Implantes Dentales , Osteogénesis , Animales , Antibacterianos/farmacología , Materiales Biocompatibles Revestidos/farmacología , Oseointegración , Propiedades de Superficie , Titanio
3.
Osteoarthritis Cartilage ; 29(12): 1701-1708, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34284113

RESUMEN

OBJECTIVE: To assess which structural abnormalities on knee MRI are associated with development of osteophytes in middle-aged subjects without radiographic knee osteoarthritis. DESIGN: We included subjects from the Osteoarthritis Initiative, aged 40-55 years, Kellgren & Lawrence grade 0 in both knees, and knee MRIs from both knees available at baseline, 24, 48 and 72 months. Structural exposures on MRI assessed using MOAKS included cartilage damage, bone marrow lesions, meniscal tear, meniscal extrusion, and Hoffa/effusion synovitis. We assessed whether each structural exposure was associated with the development of osteophytes on MRI in the medial and lateral tibiofemoral, and patellofemoral compartment. We estimated hazard ratios (HR) including 95% confidence intervals (CI) for osteophyte development using a mixed complementary log-log regression model adjusted for age, sex, and body mass index. RESULTS: We included 680 knees from 340 subjects with a mean (SD) age of 50 years (3.0), and 51% men. In the medial tibiofemoral compartment, the absolute risk of osteophyte development in the first 24-month period was 4% in knees without, and 15% in knees with medial meniscal tear. Corresponding adjusted HR was 6.6 (95%CI = 3.4-12.9). In the lateral tibiofemoral compartment, the adjusted HR for developing osteophytes having a lateral meniscal tear was 3.3 (95%CI = 1.3-8.4). In the patellofemoral compartment, patellofemoral cartilage damage was most clearly associated with developing osteophytes (HR = 2.6, 95%CI = 1.8-3.7). CONCLUSIONS: Meniscal tear seem to be the strongest structural risk factor for the development of tibiofemoral osteophytes, and patellofemoral cartilage damage for the development of patellofemoral osteophytes, respectively. Local biomechanical factors are important in early osteophyte development.


Asunto(s)
Articulación de la Rodilla/diagnóstico por imagen , Osteofito/diagnóstico por imagen , Adulto , Cartílago Articular/lesiones , Estudios de Cohortes , Femenino , Humanos , Estudios Longitudinales , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Lesiones de Menisco Tibial
4.
J Dent Res ; 98(2): 234-241, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30426815

RESUMEN

Basic-helix-loop-helix (bHLH) transcription factors play an important role in various organs' development; however, a tooth-specific bHLH factor has not been reported. In this study, we identified a novel tooth-specific bHLH transcription factor, which we named AmeloD, by screening a tooth germ complementary DNA (cDNA) library using a yeast 2-hybrid system. AmeloD was mapped onto the mouse chromosome 1q32. Phylogenetic analysis showed that AmeloD belongs to the achaete-scute complex-like ( ASCL) gene family and is a homologue of ASCL5. AmeloD was uniquely expressed in the inner enamel epithelium (IEE), but its expression was suppressed after IEE cell differentiation into ameloblasts. Furthermore, AmeloD expression showed an inverse expression pattern with the epithelial cell-specific cell-cell adhesion molecule E-cadherin in the dental epithelium. Overexpression of AmeloD in dental epithelial cell line CLDE cells resulted in E-cadherin suppression. We found that AmeloD bound to E-box cis-regulatory elements in the proximal promoter region of the E-cadherin gene. These results reveal that AmeloD functions as a suppressor of E-cadherin transcription in IEE cells. Our study demonstrated that AmeloD is a novel tooth-specific bHLH transcription factor that may regulate tooth development through the suppression of E-cadherin in IEE cells.


Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Células Epiteliales/citología , Diente/citología , Factores Generales de Transcripción/metabolismo , Factores de Transcripción , Animales , Cadherinas/metabolismo , Proliferación Celular , Células Epiteliales/metabolismo , Regulación de la Expresión Génica , Ratones , Odontogénesis , Filogenia , Diente/metabolismo
5.
Osteoarthritis Cartilage ; 23(11): 1858-64, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26028139

RESUMEN

OBJECTIVE: The aim of this study was to examine the osteoarthritis (OA)-related structural changes associated with histological synovitis in end-stage knee OA patients. METHODS: Forty end-stage knee OA patients (female: 88%, mean age: 71.8 y) were enrolled. All participants underwent 3.0-T MRI. The structural changes, such as cartilage morphology, subchondral bone marrow lesion (BML), subchondral bone cyst (SBC), subchondral bone attrition (SBA), osteophytes, meniscal lesion and synovitis, were scored using the whole-organ MRI scoring (WORMS) method. Synovial samples were obtained from five regions of interest (ROIs) of the knee joint during total joint replacement surgery. The associations between the histological synovitis score (HSS) and WORMS or the synovial expression levels of cyclooxygenase (COX)-2, interleukin (IL)-1ß, IL-6 and transforming growth factor (TGF)-ß were examined using Spearman's correlation coefficient. RESULTS: Among the seven OA-related structural changes, the BML, SBC, SBA and synovitis were significantly associated with the HSS (r = 0.33, 0.35, 0.48 and 0.36, respectively), while other morphological changes were not. Although synovial COX-2, IL-1ß or IL-6 expression levels were not associated with the HSS, the synovial TGF-ß expression levels were associated with the HSS. CONCLUSION: The presence of BML, SBC and SBA was associated with histological synovitis in end-stage knee OA patients.


Asunto(s)
Quistes Óseos/patología , Enfermedades de la Médula Ósea/patología , Médula Ósea/patología , Cartílago Articular/patología , Imagen por Resonancia Magnética/métodos , Osteoartritis de la Rodilla/patología , Sinovitis/patología , Anciano , Quistes Óseos/complicaciones , Quistes Óseos/metabolismo , Enfermedades de la Médula Ósea/complicaciones , Enfermedades de la Médula Ósea/metabolismo , Estudios Transversales , Citocinas/biosíntesis , Femenino , Humanos , Inmunohistoquímica , Masculino , Osteoartritis de la Rodilla/complicaciones , Osteoartritis de la Rodilla/metabolismo , Líquido Sinovial/metabolismo , Sinovitis/etiología , Sinovitis/metabolismo
6.
Br J Radiol ; 88(1046): 20140596, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25490255

RESUMEN

OBJECTIVE: To evaluate the risk of radiation pneumonitis (RP) after stereotactic radiotherapy (SBRT) for patients presenting with severe pulmonary emphysema. METHODS: This study included 40 patients with Stage I non-small-cell lung cancer who underwent SBRT, 75 Gy given in 30 fractions, at the Tokyo Medical University, Tokyo, Japan, between February 2010 and February 2013. The median age of the patients was 79 years (range, 49-90 years), and the male:female ratio was 24:16. There were 20 T1 and 20 T2 tumours. 17 patients had emphysema, 6 had slight interstitial changes on CT images and the remaining 17 had no underlying lung disease. The level of emphysema was classified into three groups according to the modified Goddard's criteria (severe: three patients, moderate: eight patients and mild: six patients). Changes in the irradiated lung following SBRT were evaluated by CT. RESULTS: On CT images, RP was detected in 34 (85%) patients, and not in 6 (15%) patients, during a median observation period of 313 days. Of the six patients, three had severe emphysema and three had no underlying lung disease. Patients with severe emphysema had lower risk of RP than those with moderate emphysema (p = 0.01), mild emphysema (p = 0.04) and no underlying lung disease (p = 0.01). CONCLUSION: Patients with severe emphysema had a low risk of RP following SBRT. ADVANCES IN KNOWLEDGE: Little is known about the association between RP and pulmonary emphysema. Patients with severe emphysema had lower risk of RP than those with no underlying lung disease.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/cirugía , Neoplasias Pulmonares/cirugía , Enfisema Pulmonar/diagnóstico , Neumonitis por Radiación/complicaciones , Radiocirugia/métodos , Anciano , Anciano de 80 o más Años , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Japón/epidemiología , Neoplasias Pulmonares/diagnóstico , Masculino , Persona de Mediana Edad , Enfisema Pulmonar/etiología , Neumonitis por Radiación/diagnóstico , Neumonitis por Radiación/epidemiología , Estudios Retrospectivos , Factores de Riesgo , Tomografía Computarizada por Rayos X
7.
Osteoarthritis Cartilage ; 22(10): 1583-9, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25278068

RESUMEN

OBJECTIVE: The aim of the present study was to examine whether the degenerative and morphological changes of articular cartilage in early stage knee osteoarthritis (OA) occurred equally for both femoral- and tibial- or patellar- articular cartilage using magnetic resonance imaging (MRI)-based analyses. DESIGN: This cross-sectional study was approved by the ethics committee of our university. Fifty patients with early stage painful knee OA were enrolled. The patients underwent 3.0 T MRI on the affected knee joint. Healthy volunteers who did not show MRI-based OA changes were also recruited as controls (n = 19). The degenerative changes of the articular cartilage were quantified by a T2 mapping analysis, and any structural changes were conducted using Whole Organ Magnetic Resonance Imaging Score (WORMS) technique. RESULTS: All patients showed MRI-detected OA morphological changes. The T2 values of femoral condyle (FC) (P < 0.0001) and groove (P = 0.0001) in patients with early stage knee OA were significantly increased in comparison to those in the control, while no significant differences in the T2 values of patellar and tibial plateau (TP) were observed between the patients and the control. The WORMS cartilage and osteophyte scores of the femoral articular cartilage were significantly higher than those in the patellar- (P = 0.001 and P = 0.007, respectively) and tibial- (P = 0.0001 and P < 0.0001, respectively) articular cartilage in the patients with early stage knee OA. CONCLUSIONS: The degradation and destruction of the femoral articular cartilage demonstrated a greater degree of deterioration than those of the tibial- and patellar- articular cartilage in patients with early stage knee OA.


Asunto(s)
Enfermedades de los Cartílagos/patología , Cartílago Articular/patología , Fémur/patología , Articulación de la Rodilla/patología , Osteoartritis de la Rodilla/patología , Rótula/patología , Tibia/patología , Adulto , Anciano , Enfermedades de los Cartílagos/etiología , Estudios de Casos y Controles , Estudios Transversales , Progresión de la Enfermedad , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Osteoartritis de la Rodilla/complicaciones , Osteofito/etiología , Osteofito/patología , Índice de Severidad de la Enfermedad
8.
Osteoarthritis Cartilage ; 21(9): 1179-84, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23973128

RESUMEN

OBJECTIVES: Knee osteoarthritis (OA) pain is suggested to be associated with inflammation and detrimental mechanical loading across the joint. In this cross-sectional study, we simultaneously examined the inflammation and alignment of the lower limb and examined how the pain components varied depending on the disease progression. DESIGN: One-hundred sixty female medial type of early- [n = 74 in Kellgren-Lawrence (K/L) 2] to advanced-stage (n = 96 in K/L >2) knee OA subjects (70.5 years on average) were enrolled. Knee pain was evaluated using a pain visual analog scale (VAS) and the pain-related subcategory of the Japanese Knee Osteoarthritis Measure (JKOM-pain). The serum interleukin (sIL)-6 level reflecting synovitis, and the high sensitivity C-reactive protein (hs-CRP) level were measured to evaluate the severity of inflammation. The anatomical axis angle (AAA) was measured as an alignment index. The ß-coefficient was estimated after adjusting for age and the body mass index (BMI) using a multiple linear regression analysis. RESULTS: Multiple linear regression analyses showed that the sIL-6 levels, but not AAA, associated with the pain VAS [ß = 10.77 (95% confidence interval (CI): 4.14-17.40), P < 0.01] and JKOM-pain scores [ß = 3.19 (95% CI: 1.93-4.44), P < 0.001] in the early stage. Conversely, AAA, but not the sIL-6 levels, was found to be associated with the pain VAS [ß = -1.29 (95% CI: -2.51 to -0.08), P < 0.05] and JKOM-pain scores [ß = -0.49 (95% CI: -0.82 to -0.16), P < 0.01] in the advanced stage. CONCLUSIONS: The presence of a higher level of sIL-6 and the varus alignment of the joint is associated with pain in early- and advanced-stage knee OA patients, respectively.


Asunto(s)
Artralgia/diagnóstico por imagen , Artralgia/epidemiología , Osteoartritis de la Rodilla/diagnóstico por imagen , Osteoartritis de la Rodilla/epidemiología , Índice de Severidad de la Enfermedad , Anciano , Artralgia/fisiopatología , Biomarcadores/sangre , Proteína C-Reactiva/metabolismo , Estudios Transversales , Progresión de la Enfermedad , Femenino , Humanos , Interleucina-6/sangre , Persona de Mediana Edad , Osteoartritis de la Rodilla/fisiopatología , Dimensión del Dolor , Radiografía , Factores de Riesgo , Sinovitis/diagnóstico por imagen , Sinovitis/epidemiología , Sinovitis/fisiopatología , Soporte de Peso/fisiología
9.
Artículo en Inglés | MEDLINE | ID: mdl-17375881

RESUMEN

The thenar motor units (MUs) were studied by the multichannel surface electromyography (EMG) technique. The median nerve was stimulated at the wrist by repetitive submaximal stimulation. Three hundred consecutive evoked responses were recorded from the thenar muscles of 5 healthy volunteers with a 32 channel matrix-type multielectrode. Seven channel F-wave waveforms in a selected electrode array were classified using a template-matching method. The F-wave parameters, amplitudes, latencies and muscle fiber conduction velocities (MFCVs), were calculated to evaluate the properties of single MU F-wave. Most of the F-waves (93.3%) were composed of a single motor unit action potential (MUAP). The numbers of MU classified from single MU F-waves in 5 subjects were 11, 8, 13, 13 and 13, respectively. Many of them (84.5%) were originated from the abductor pollicis brevis (APB), and there were a few MUs originated from the flexor pollicis brevis (FPB). Significant correlations were found between F-wave amplitudes and latencies in 3 subjects.


Asunto(s)
Potenciales de Acción/fisiología , Electromiografía/métodos , Neuronas Motoras/fisiología , Fibras Musculares Esqueléticas/fisiología , Unión Neuromuscular/fisiología , Tiempo de Reacción/fisiología , Pulgar/inervación , Adulto , Humanos , Masculino , Transmisión Sináptica/fisiología , Pulgar/fisiología
11.
Brain Topogr ; 13(4): 269-74, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11545155

RESUMEN

A patient who had experienced an attack of transient global amnesia (TGA) was examined using neurophysiological methods. Magnetoencephalography (MEG) was performed and the Wechsler Memory Scale-Revised (WMS-R) test was administered at 5 days and at more than a month after the TGA episode. MEG data on neuronal activity obtained while the patient was undertaking a working memory task and during rest were analyzed using the wavelet-crosscorrelation method, which reveals time-lag and information flow between related sites in the brain. The WMS-R memory scores showed dramatic improvement when the test was administered a month following the attack, although no significant changes were observed in EEG, MRI and SPECT data. The MEG study revealed that under a working memory load how the neuron works functionally and the information propagates assembly within the right hemisphere, and that these brain functions were not performed adequately shortly after the TGA attack.


Asunto(s)
Amnesia Global Transitoria/diagnóstico , Amnesia Global Transitoria/fisiopatología , Encéfalo/fisiopatología , Magnetoencefalografía , Amnesia Global Transitoria/psicología , Encéfalo/diagnóstico por imagen , Femenino , Humanos , Persona de Mediana Edad , Neurofisiología/métodos , Factores de Tiempo , Tomografía Computarizada de Emisión de Fotón Único , Escalas de Wechsler
12.
J Exp Med ; 193(3): 399-404, 2001 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-11157060

RESUMEN

Reduced mechanical stress to bone in bedridden patients and astronauts leads to bone loss and increase in fracture risk which is one of the major medical and health issues in modern aging society and space medicine. However, no molecule involved in the mechanisms underlying this phenomenon has been identified to date. Osteopontin (OPN) is one of the major noncollagenous proteins in bone matrix, but its function in mediating physical-force effects on bone in vivo has not been known. To investigate the possible requirement for OPN in the transduction of mechanical signaling in bone metabolism in vivo, we examined the effect of unloading on the bones of OPN(-/-) mice using a tail suspension model. In contrast to the tail suspension-induced bone loss in wild-type mice, OPN(-/-) mice did not lose bone. Elevation of urinary deoxypyridinoline levels due to unloading was observed in wild-type but not in OPN(-/-) mice. Analysis of the mechanisms of OPN deficiency-dependent reduction in bone on the cellular basis resulted in two unexpected findings. First, osteoclasts, which were increased by unloading in wild-type mice, were not increased by tail suspension in OPN(-/-) mice. Second, measures of osteoblastic bone formation, which were decreased in wild-type mice by unloading, were not altered in OPN(-/-) mice. These observations indicate that the presence of OPN is a prerequisite for the activation of osteoclastic bone resorption and for the reduction in osteoblastic bone formation in unloaded mice. Thus, OPN is a molecule required for the bone loss induced by mechanical stress that regulates the functions of osteoblasts and osteoclasts.


Asunto(s)
Osteoblastos/fisiología , Osteoclastos/fisiología , Sialoglicoproteínas/fisiología , Aminoácidos/orina , Animales , Resorción Ósea/patología , Femenino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Osteoclastos/citología , Osteopontina , Sialoglicoproteínas/genética , Sialoglicoproteínas/metabolismo , Estrés Mecánico
13.
Clin Calcium ; 11(4): 404-10, 2001 Apr.
Artículo en Japonés | MEDLINE | ID: mdl-15775533

RESUMEN

Bone metabolism is regulated not only by the nutrition supplied by vessel but also by the signals from the cells in vascular tissues. Identification of such signaling molecules has been the major issue in the field of research on the relationship between bone and vasculatures. This review touches on the recent findings on the expression and functions of such signaling molecules including VEGF, MMP and non-collagenous bone matrix proteins.

14.
Clin Calcium ; 11(10): 1315-20, 2001 Oct.
Artículo en Japonés | MEDLINE | ID: mdl-15775646

RESUMEN

Bone formation requires phosphate to calcify the osteoid produced by osteoblasts, Pit-1, a natrium-phosphate cotransporter, is expressed in osteoblasts and its expression levels are regulated developmentally and also by hormones and cytokines. Another type of phosphate transporter is expressed in osteoclasts and its function is required for bone resumption. These observations suggest that phosphate transport into the bone cells may play a role in regulation of bone formation and resorption in vivo and in the pathological situation in patients with bone diseases.

15.
Front Med Biol Eng ; 10(3): 261-7, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11014685

RESUMEN

Periodical and long-term examination of the cardiac function is important for detecting early-stage disorders, and contributing to chronodiagnosis and chronotherapeutics. Frequent or daily examination utilizing the present test procedures, however, places the patient under stress even when it is administered at home and not during a hospital visit. In order to cope with this issue, monitoring systems whereby a patient is not aware of being examined were developed taking the electrocardiogram (ECG) as an example. The ECG was monitored while the patient was taking a bath or sleeping in bed. The system did not utilize any body surface electrodes but introduced in-water electrodes in the bath and textile electrodes on the bed. These systems made long-term observation feasible without imposing any stress on the patient.


Asunto(s)
Electrocardiografía/instrumentación , Corazón/fisiología , Monitoreo Fisiológico , Baños , Electrocardiografía/métodos , Diseño de Equipo , Frecuencia Cardíaca , Calor , Humanos , Postura , Descanso , Sueño , Factores de Tiempo
16.
BJU Int ; 85(6): 754-8, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10759679

RESUMEN

OBJECTIVE: To evaluate in an animal model the haemostatic efficacy of vaporizing-cutting (VC) electrodes recently developed for use in high-energy transurethral resection of the prostate (TURP). MATERIALS AND METHODS: Four VC electrodes were assessed for their haemostatic efficacy in the muscle and liver of pigs (in vitro) and dogs (in vivo). The devices tested were the roller-cutting and Vapor Cut (Karl Storz GmbH, Germany); the Wedge (Boston Scientific Corp., Boston, USA); and the Uroloop (Endocare Inc., Irvine, CA). In each the depth of the desiccated zone was compared with that produced by a standard cutting loop electrode. Each electrode was attached to a scanning system (developed previously) that allowed the electrode pressure on the tissue surface (in 3% sorbitol solution) and the running speed to be adjusted. The same generator was used with all devices. The tissue (muscle or liver) was cut by running the electrode over the surface at 200, 250 or 300 W, with the loop electrode used as the reference. After completing the procedure, the surgical wound and the surrounding tissue were dissected out and the depth of the heat-affected zone (HAZ, defined as the desiccated zone) measured. RESULTS: In pig muscle (stroke speed 5 mm/s) there was no significant difference in the depth of the HAZ between the four VC electrodes and the loop, or among the VC electrodes at any of the power levels tested. In pig liver (stroke speed 5 mm/s), the roller cutting and Vapor Cut electrodes produced a thicker HAZ than the loop at all power levels tested (P < 0.01). The Wedge electrode produced a significantly thicker HAZ than the loop at 200 and 300 W (P < 0.01). There were no significant differences in HAZ among the VC electrodes at any power level. In dog muscle in vivo (stroke speed 10 mm/s), the roller cutting, Vapor Cut and Wedge electrodes produced a significantly thicker HAZ at 250 W than the loop at 150 W (the usual power for TURP) (P < 0.01). There was no significant difference among the VC electrodes. In dog liver in vivo (stroke speed 10 mm/s), the roller cutting electrode produced a significantly thicker HAZ at 250 W than the loop at 150 W (P < 0.01). CONCLUSIONS: The present VC electrodes produced a thicker desiccation zone at higher powers (200-300 W) than the standard loop at the usual power (150 W). The four VC electrodes produced a similar desiccation zone. With pig muscle and liver in vitro, regular loops used at a higher power created a desiccation zone that was 70-80% of the depth created by the VC electrodes.


Asunto(s)
Electrocoagulación/métodos , Hígado/cirugía , Músculo Esquelético/cirugía , Animales , Perros , Electrocoagulación/instrumentación , Electrodos , Hígado/patología , Músculo Esquelético/patología , Porcinos
18.
Physiol Meas ; 20(4): 369-75, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10593230

RESUMEN

Cycling on an ergometer is one effective means of measuring cardiovascular function while applying stress on the heart. Bathing in a hot water bath applies a low stress to the heart. The electrocardiograms of a healthy adult male (aged 35 at the start of study) were recorded while taking a hot water bath with no electrode attached to the body over a period of 2 years (376 days over a 762 day period). The recovery speed following the initial overshoot of the heart rate (HR) was observed. The bathtub was designed for the automatic acquisition of ECG data. Immediately after immersion in the tub, the HR reached a peak within 20 s and then exponentially decreased toward the lowest rate in the 120 s of bathing. The initial recovery speed of the HR from the stress of bathing had a specific rhythm in the subject. Spectrum analysis of the speed series indicated that slow recovery speed appeared in cyclic periods of approximately 1 year, 42 days and 17 days. The methodology may provide a chronodiagnostic index of an exercise test for cardiovascular function.


Asunto(s)
Baños , Frecuencia Cardíaca , Inmersión/fisiopatología , Estrés Fisiológico/fisiopatología , Adaptación Fisiológica , Adulto , Algoritmos , Electrocardiografía , Prueba de Esfuerzo , Humanos , Masculino , Persona de Mediana Edad , Monitoreo Fisiológico , Valores de Referencia , Procesamiento de Señales Asistido por Computador
19.
Am J Gastroenterol ; 94(3): 650-4, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10086646

RESUMEN

OBJECTIVE: Des-gamma-carboxy prothrombin (DCP), also called protein induced by vitamin K absence or antagonist II (PIVKA-II), is a tumor marker complementary to AFP for the diagnosis of hepatocellular carcinoma (HCC). Currently available immunoassays for DCP are not sensitive enough to detect HCC at an early stage. Recently, two new immunoassays with enhanced sensitivity were developed. The aim of this study was to assess the diagnostic values of the new methods in patients with small-sized HCC. METHODS: Coded serum samples obtained from 36 patients with small-sized and single-nodular HCC (< or = 3 cm in diameter) and 49 patients with posthepatitic cirrhosis not carrying HCC were analyzed. DCP levels were determined in three different ways: 1) conventional EIA; 2) a new immunoassay using the electrochemiluminescence (ECLIA) detection system; and 3) a new immunoradiometric assay (IRMA). Lectin-reactive profiles of AFP (AFP-L3) were also determined. RESULTS: In 36 patients with small-sized HCC, the rates of abnormal values obtained by the conventional, ECLIA, and IRMA methods were 2.7%, 27.8%, and 16.7%, respectively. An ROC analysis of the two new methods (ECLIA vs IRMA) revealed a better performance by the ECLIA method (p < 0.05). The true positive rate of AFP-L3 was 22.2%, whereas a combination assay of ECLIA for DCP and AFP-L3 resulted in a 41.7% sensitivity with a specificity of 90%. CONCLUSIONS: Compared with the conventional method, the sensitivity in detecting small-sized HCC was increased in the two new DCP immunoassays (ECLIA and IRMA). The overall performance as evaluated by an ROC analysis was significantly better in ECLIA than in IRMA.


Asunto(s)
Biomarcadores de Tumor/sangre , Biomarcadores , Carcinoma Hepatocelular/diagnóstico , Inmunoensayo , Neoplasias Hepáticas/diagnóstico , Precursores de Proteínas/análisis , Protrombina/análisis , Carcinoma Hepatocelular/patología , Femenino , Humanos , Inmunoensayo/métodos , Ensayo Inmunorradiométrico , Neoplasias Hepáticas/patología , Mediciones Luminiscentes , Masculino , Valor Predictivo de las Pruebas , Curva ROC , Sensibilidad y Especificidad
20.
Int J Med Inform ; 50(1-3): 81-5, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9726496

RESUMEN

A system for medical informatics education for medical students has been developed in the medical school. This paper describes the concept underlying the development of this system and its progressive outcomes over 8 years. In order to stimulate students to acquire computer-related knowledge and skills, this subject has been integrated into the course works of various medical subjects such as physiology. In addition, acquired knowledge and skills are evaluated within each subject by the production of reports for example, using computers. This provides a concrete example for students of the relevance of the information sciences to the solving of medical problems. A well equipped computer facility for the study of medicine also plays a significant role in inspiring student incentive. A computer room equipped with Macintosh computers was opened adjacent to the main medical library and is used in the same manner as the library, with books replaced by computers. In addition, all new students acquire their own Macintosh PowerBook. These various initiations have facilitated concept that the computer may be applied to medical problem solving at any time or place and may become as commonplace as a pen in daily medical practice.


Asunto(s)
Educación de Pregrado en Medicina , Docentes , Informática Médica/educación , Computadores/estadística & datos numéricos , Evaluación Educacional , Japón , Bibliotecas Médicas , Motivación , Estudiantes de Medicina/psicología
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