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1.
Proc Inst Mech Eng H ; 236(2): 269-278, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34546113

RESUMEN

The use of supportive underwear has been applied for preventing stress urinary incontinence (SUI) which is caused by descent of the bladder neck due to weakness in the pelvic floor muscles, because it is known that SUI can be improved by elevating the descended bladder neck. However, appropriate approaches to the underwear design are still being explored. In order to establish an appropriate first-order design strategy for supportive underwear, clarifying the relationship between the pressure from the underwear and the amount of elevation of the bladder neck is necessary. We constructed a finite element model of the pelvis based on magnetic resonance images of a subject in an upright position, experimentally explored Young's modulus of the soft tissue and analyzed the amount of elevation of the bladder neck when changing the combination of applied pressures from the underwear. The position of the bladder neck relatively elevated when the pressure in the region from the abdomen to the pubis decreased and when the pressure in the region from the perineum to the coccyx increased, suggesting an appropriate design for the supportive underwear.


Asunto(s)
Vejiga Urinaria , Incontinencia Urinaria de Esfuerzo , Abdomen , Femenino , Análisis de Elementos Finitos , Humanos , Diafragma Pélvico/diagnóstico por imagen , Vejiga Urinaria/diagnóstico por imagen
2.
Front Bioeng Biotechnol ; 9: 684043, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34409020

RESUMEN

Experimental studies have demonstrated a relationship between spinal injury severity and vertebral kinematics, influenced by the initial spinal alignment of automotive occupants. Spinal alignment has been considered one of the possible causes of gender differences in the risk of sustaining spinal injuries. To predict vertebral kinematics and investigate spinal injury mechanisms, including gender-related mechanisms, under different seat back inclinations, it is needed to investigate the effect of the seat back inclination on initial spinal alignment in automotive seating postures for both men and women. The purpose of this study was to investigate the effect of the seat back inclination on spinal alignments, comparing spinal alignments of automotive seating postures in the 20° and 25° seat back angle and standing and supine postures. The spinal columns of 11 female and 12 male volunteers in automotive seating, standing, and supine postures were scanned in an upright open magnetic resonance imaging system. Patterns of their spinal alignments were analyzed using Multidimensional Scaling presented in a distribution map. Spinal segmental angles (cervical curvature, T1 slope, total thoracic kyphosis, upper thoracic kyphosis, lower thoracic kyphosis, lumbar lordosis, and sacral slope) were also measured using the imaging data. In the maximum individual variances in spinal alignment, a relationship between the cervical and thoracic spinal alignment was found in multidimensional scaling analyses. Subjects with a more lordotic cervical spine had a pronounced kyphotic thoracic spine, whereas subjects with a straighter to kyphotic cervical spine had a less kyphotic thoracic spine. When categorizing spinal alignments into two groups based on the spinal segmental angle of cervical curvature, spinal alignments with a lordotic cervical spine showed significantly greater absolute average values of T1 slope, total thoracic kyphosis, and lower thoracic kyphosis for both the 20° and 25° seat back angles. For automotive seating postures, the gender difference in spinal alignment was almost straight cervical and less-kyphotic thoracic spine for the female subjects and lordotic cervical and more pronounced kyphotic thoracic spine for the male subjects. The most prominent influence of seatback inclination appeared in Total thoracic kyphosis, with increased angles for 25° seat back, 8.0° greater in spinal alignments with a lordotic cervical spine, 3.2° greater in spinal alignments with a kyphotic cervical spine. The difference in total thoracic kyphosis between the two seatback angles and between the seating posture with the 20° seat back angle and the standing posture was greater for spinal alignments with a lordotic cervical spine than for spinal alignments with a kyphotic cervical spine. The female subjects in this study had a tendency toward the kyphotic cervical spine. Some of the differences between average gender-specific spinal alignments may be explained by the findings observed in the differences between spinal alignments with a lordotic and kyphotic cervical spine.

3.
Molecules ; 26(5)2021 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-33806326

RESUMEN

Recent evidence suggests that the formation of soluble amyloid ß (Aß) aggregates with high toxicity, such as oligomers and protofibrils, is a key event that causes Alzheimer's disease (AD). However, understanding the pathophysiological role of such soluble Aß aggregates in the brain in vivo could be difficult due to the lack of a clinically available method to detect, visualize, and quantify soluble Aß aggregates in the brain. We had synthesized a novel fluorinated curcumin derivative with a fixed keto form, named as Shiga-Y51, which exhibited high selectivity to Aß oligomers in vitro. In this study, we investigated the in vivo detection of Aß oligomers by fluorine-19 (19F) magnetic resonance imaging (MRI) using Shiga-Y51 in an APP/PS1 double transgenic mouse model of AD. Significantly high levels of 19F signals were detected in the upper forebrain region of APP/PS1 mice compared with wild-type mice. Moreover, the highest levels of Aß oligomers were detected in the upper forebrain region of APP/PS1 mice in enzyme-linked immunosorbent assay. These findings suggested that 19F-MRI using Shiga-Y51 detected Aß oligomers in the in vivo brain. Therefore, 19F-MRI using Shiga-Y51 with a 7 T MR scanner could be a powerful tool for imaging Aß oligomers in the brain.


Asunto(s)
Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/metabolismo , Encéfalo/patología , Curcumina/metabolismo , Modelos Animales de Enfermedad , Imagen por Resonancia Magnética con Fluor-19/métodos , Placa Amiloide/patología , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/química , Animales , Encéfalo/metabolismo , Curcumina/química , Femenino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Placa Amiloide/metabolismo
4.
Magn Reson Med Sci ; 20(3): 264-271, 2021 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-32830172

RESUMEN

PURPOSE: (1) To evaluate the enhancement patterns of an ultrasmall superparamagnetic iron oxide contrast agent (USPIO-CA) compared with those of a gadolinium-based contrast agent (Gd-BCA). (2) To compare the histologic distribution of USPIO-related iron particles (USPIO-IPs) with the USPIO-enhancement area in the early vascular and in the cellular imaging phase (E- and L-phase, respectively) after intravenous CA administration. METHODS: We performed USPIO-enhanced MRI of N-ethyl-N-nitrosourea (ENU)-induced endogenous rat glioma, including spin-echo (SE) T1-weighted images (T1WIs) and gradient-recalled-echo (GRE) T2-weighted images (T2WIs), before and at 3-6 h after USPIO-CA administration for E-phase images. For L-phase images, MRI was performed at 16-19 and 62-69 h after administration. Two observers determined the USPIO-enhancement area on E-phase images and Gd-enhancement areas. We compared the USPIO-enhancement size (USPIO-ES) and Gd-ES on SE T1WIs, and the hypo-intense USPIO-ES on GRE T2WIs and Gd-ES using the Wilcoxon signed-rank test. In addition, two raters visually evaluated the correspondence between the histologic distribution of USPIO-IPs and the USPIO-enhancement area on corresponding GRE T2WIs at each phase using a 3-rating scale. RESULTS: Significantly smaller hyper-intense, hypo-intense and combined hyper-/hypo-intense areas were observed on USPIO-enhanced SE T1WIs compared with Gd-enhanced images (all P < 0.001). The hypo-intense USPIO-ES on GRE T2WIs was significantly smaller than the Gd-ES (P = 0.001). The distribution of USPIO-IPs on histopathological specimen and USPIO-enhancement on GRE T2WIs exhibited poor agreement in 5 of 9 tumors with enhancement from rats sacrificed early. The distribution of microglia containing USPIO-IPs corresponded with the pattern of USPIO-enhancement in the 2 tumors with late enhancement. CONCLUSION: The enhancement pattern and size of USPIO-CA in a rat glioma model were statistically different from those of Gd-BCA. Our histological data suggests that USPIO-enhanced MRI offers vascular bed imaging in E-phase and might depict the intra-tumoral distribution of immune effector cells in L-phase.


Asunto(s)
Glioma , Nanopartículas de Magnetita , Animales , Medios de Contraste , Dextranos , Etilnitrosourea , Óxido Ferrosoférrico , Glioma/diagnóstico por imagen , Imagen por Resonancia Magnética , Óxidos , Ratas
5.
Front Neurosci ; 14: 845, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32922259

RESUMEN

We have previously reported that casein hydrolysate, CH-3, from bovine milk and casein-derived tripeptide Met-Lys-Pro (MKP) has ACE inhibitory activity and reduces blood pressure. In this study, we investigated the therapeutic effects of MKP in a hypertensive rat model (7-week-old male SHRSP/Izm rats). For long term evaluation, rats were fed either a diet containing CH-3 or normal diet. The survival rate of SHRSP rats was significantly improved by intake of CH-3 for 181 days. For short term evaluation, rats were orally administered synthetic tripeptide MKP or distilled water for 4 weeks. MRI study demonstrated that hemorrhagic lesions were observed in two of five rats in the control group, while no hemorrhagic lesions were observed in the MKP group. Volumetric analysis using MRI revealed that MKP administration inhibited atrophy of diencephalic regions. Histological examinations revealed that hemorrhage areas and astrogliosis in the hippocampus and cerebral cortex were lower in the MKP group than in the control group. Gene expression analysis indicated that MKP administration reduced expression of genes related to cerebral circulation insufficiency such as immune responses (Cd74 and Prkcd), response to hypoxia (Ddit4, Apold1, and Prkcd), reactive oxygen species metabolic process (Ddit4 and Pdk4), and apoptotic process (Ddit4, Prkcd, and Sgk1), suggesting that MKP administration prevented cerebral ischemia associated with hypertension. In addition, some genes encoding responses to hormone stimulus (Fos, Dusp1, and Sik1) were also downregulated. Serum aldosterone and corticosterone levels were also significantly decreased following MKP administration. The present study indicates that MKP shows neuroprotective effects in SHRSP rats by regulating cerebral circulation insufficiency and corticoid levels. MKP administration may therefore be a potential therapeutic strategy for hypertensive brain diseases such as cerebrovascular disease.

6.
PLoS One ; 15(5): e0232397, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32365096

RESUMEN

Biometric ratios of the relative length of the rays in the hand have been analyzed between primate species in the light of their hand function or phylogeny. However, how relative lengths among phalanges are mechanically linked to the grasping function of primates with different locomotor behaviors remains unclear. To clarify this, we calculated cross and triple-ratios, which are related to the torque distribution, and the torque generation mode at different joint angles using the lengths of the phalanges and metacarpal bones in 52 primates belonging to 25 species. The torque exerted on the finger joint and traction force of the flexor tendons necessary for a cylindrical grip and a suspensory hand posture were calculated using the moment arm of flexor tendons measured on magnetic resonance images, and were compared among Hylobates spp., Ateles sp., and Papio hamadryas. Finally, the torques calculated from the model were validated by a mechanical study detecting the force exerted on the phalanx by pulling the digital flexor muscles during suspension in these three species. Canonical discriminant analysis of cross and triple-ratios classified primates almost in accordance with their current classification based on locomotor behavior. The traction force was markedly reduced with flexion of the MCP joint parallel to the torque in brachiating primates; this was notably lower in the terrestrial quadrupedal primates than in the arboreal primates at mild flexion. Our mechanical study supported these features in the torque and traction force generation efficiencies. Our results suggest that suspensory or terrestrial quadrupedal primates have hand structures that can exert more torque at a suspensory posture, or palmigrade and digitigrade locomotion, respectively. Furthermore, our study suggests availability of the cross and triple-ratios as one of the indicators to estimate the hand function from the skeletal structure.


Asunto(s)
Mano/anatomía & histología , Mano/fisiología , Locomoción/fisiología , Primates/anatomía & histología , Primates/fisiología , Animales , Atelinae/anatomía & histología , Atelinae/fisiología , Fenómenos Biomecánicos , Falanges de los Dedos de la Mano/anatomía & histología , Falanges de los Dedos de la Mano/diagnóstico por imagen , Falanges de los Dedos de la Mano/fisiología , Análisis de Elementos Finitos , Mano/diagnóstico por imagen , Fuerza de la Mano/fisiología , Humanos , Hylobates/anatomía & histología , Hylobates/fisiología , Imagen por Resonancia Magnética , Huesos del Metacarpo/anatomía & histología , Huesos del Metacarpo/diagnóstico por imagen , Huesos del Metacarpo/fisiología , Fenómenos Fisiológicos Musculoesqueléticos , Sistema Musculoesquelético/anatomía & histología , Papio hamadryas/anatomía & histología , Papio hamadryas/fisiología , Especificidad de la Especie , Tomografía Computarizada por Rayos X , Torque
7.
Med Phys ; 47(3): 850-858, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31829440

RESUMEN

PURPOSE: Image guidance is crucial for percutaneous tumor ablations, enabling accurate needle-like applicator placement into target tumors while avoiding tissues that are sensitive to injury and/or correcting needle deflection. Although ultrasound (US) is widely used for image guidance, magnetic resonance (MR) is preferable due to its superior soft tissue contrast. The objective of this study was to develop and evaluate an MR and US multi-modal image-guided navigation system with a needle manipulator to enable US-guided applicator placement during MR imaging (MRI)-guided percutaneous tumor ablation. METHODS: The MRI-compatible needle manipulator with US probe was installed adjacent to a 3 Tesla MRI scanner patient table. Coordinate systems for the MR image, patient table, manipulator, and US probe were all registered using an optical tracking sensor. The patient was initially scanned in the MRI scanner bore for planning and then moved outside the bore for treatment. Needle insertion was guided by real-time US imaging fused with the reformatted static MR image to enhance soft tissue contrast. Feasibility, targeting accuracy, and MR compatibility of the system were evaluated using a bovine liver and agar phantoms. RESULTS: Targeting error for 50 needle insertions was 1.6 ± 0.6 mm (mean ± standard deviation). The experiment confirmed that fused MR and US images provided real-time needle localization against static MR images with soft tissue contrast. CONCLUSIONS: The proposed MR and US multi-modal image-guided navigation system using a needle manipulator enabled accurate needle insertion by taking advantage of static MR and real-time US images simultaneously. Real-time visualization helped determine needle depth, tissue monitoring surrounding the needle path, target organ shifts, and needle deviation from the path.


Asunto(s)
Técnicas de Ablación/instrumentación , Biopsia Guiada por Imagen/instrumentación , Imagen por Resonancia Magnética , Agujas , Animales , Bovinos , Estudios de Factibilidad , Procesamiento de Imagen Asistido por Computador , Hígado/diagnóstico por imagen , Hígado/cirugía , Fantasmas de Imagen , Ultrasonografía , Flujo de Trabajo
8.
J Biomech Eng ; 141(12)2019 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-31596923

RESUMEN

The purpose of this study was to investigate the relationship between cervical, thoracic, and lumbar spinal alignments in one automotive occupant seated posture. An image dataset of the spinal column in the automotive seated posture, previously acquired by an upright open magnetic resonance imaging (MRI) system, was re-analyzed in this study. Spinal alignments were presented by the geometrical centers of the vertebral bodies extracted from the image data. Cervical, thoracic, and lumbar spinal alignments were analyzed separately with multidimensional scaling (MDS). Based on distribution maps of cervical, thoracic, and lumbar spinal alignments created by MDS, representative spinal alignment patterns of the cervical, thoracic, and lumbar spines and the relationship between cervical, thoracic, and lumbar spinal alignments were investigated. As a result, this study found a correlation between cervical and thoracic spinal alignments in an automotive occupant seated posture. According to representative spinal alignment patterns illustrated by the distribution map of spinal alignments, subjects who had kyphotic cervical spinal alignment tended to have less kyphotic thoracic spinal alignment, while subjects who had lordotic cervical spinal alignment tended to have more kyphotic thoracic spinal alignment. For lumbar spinal alignments, no prominent relationship was found between cervical and thoracic spinal alignment in the seated condition of this study.

9.
Int Urogynecol J ; 30(7): 1093-1099, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30627829

RESUMEN

INTRODUCTION AND HYPOTHESIS: In our previous single-arm pilot study, we reported that ready-made supportive underwear (shaper) was effective in elevating the bladder neck and reducing urinary incontinence (UI) symptoms. The aim of this study was to determine the effects of wearing a shaper compared with pelvic floor muscle training (PFMT) at home using a training compact disc with music, or no treatment, in an assessor-blinded randomized control trial, on reducing UI symptoms. METHODS: Participants aged 30-59 years with symptoms of stress urinary incontinence were randomly assigned to three groups: the shaper group, PFMT group, and no treatment group. The UI episodes/week and the Japanese version of the International Consultation on Incontinence Questionnaire Short-Form were compared between the baseline and the 6th or 12th week of the intervention period. RESULTS: Eighty-nine women who completed the 12-week intervention period were analyzed. After the 12-week intervention period, the improvement rate in UI symptoms (ratio of the case number in which the UI episodes/week decreased at least 50% from the baseline) was 73.3% (22/30 women) in the shaper group, 74.2% (23/31 women) in the PFMT group, and 25.0% (7/28 women) in the no treatment group. The improvement rate in UI symptoms in the shaper and PFMT groups was significantly higher than that in the no treatment group (both P < 0.001). CONCLUSIONS: Wearing supportive underwear (shaper) was almost as effective as PFMT at home in reducing UI symptoms.


Asunto(s)
Vestuario , Terapia por Ejercicio/métodos , Incontinencia Urinaria de Esfuerzo/terapia , Adulto , Femenino , Humanos , Persona de Mediana Edad , Diafragma Pélvico/fisiopatología , Método Simple Ciego , Resultado del Tratamiento
10.
J Neurosci Res ; 96(5): 841-851, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29063641

RESUMEN

Aggregation of tau into neurofibrillary tangles (NFTs) is characteristic of tauopathies, including Alzheimer's disease. Recent advances in tau imaging have attracted much attention because of its potential contributions to early diagnosis and monitoring of disease progress. Fluorine-19 magnetic resonance imaging (19 F-MRI) may be extremely useful for tau imaging once a high-quality probe has been formulated. In this investigation, a novel fluorine-19-labeling compound has been developed as a probe for tau imaging using 19 F-MRI. This compound is a buta-1,3-diene derivative with a polyethylene glycol side chain bearing a CF3 group and is known as Shiga-X35. Female rTg4510 mice (a mouse model of tauopathy) and wild-type mice were intravenously injected with Shiga-X35, and magnetic resonance imaging of each mouse's head was conducted in a 7.0-T horizontal-bore magnetic resonance scanner. The 19 F-MRI in rTg4510 mice showed an intense signal in the forebrain region. Analysis of the signal intensity in the forebrain region revealed a significant accumulation of fluorine-19 magnetic resonance signal in the rTg4510 mice compared with the wild-type mice. Histological analysis showed fluorescent signals of Shiga-X35 binding to the NFTs in the brain sections of rTg4510 mice. Data collected as part of this investigation indicate that 19 F-MRI using Shiga-X35 could be a promising tool to evaluate tau pathology in the brain.


Asunto(s)
Benzoxazoles/química , Butadienos/química , Imagen por Resonancia Magnética con Fluor-19/métodos , Flúor , Tauopatías/diagnóstico por imagen , Anciano , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/metabolismo , Animales , Benzoxazoles/síntesis química , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Butadienos/síntesis química , Modelos Animales de Enfermedad , Femenino , Humanos , Masculino , Ratones , Ratones Transgénicos , Ovillos Neurofibrilares/metabolismo , Proteínas tau/metabolismo
11.
J Neurosci Res ; 95(7): 1485-1494, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-27792255

RESUMEN

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra projecting to the striatum. It has been estimated that approximately 80% of the striatal dopamine and 50% of nigral dopaminergic neurons are lost before the onset of typical motor symptoms, indicating that early diagnosis of PD using noninvasive imaging is feasible. Fluorine-19 (19 F) magnetic resonance imaging (MRI) represents a highly sensitive, easily available, low-background, and cost-effective approach to evaluate dopaminergic function using non-radioactive fluorine-containing dopaminergic agents. The aim of this study was to find a potent 19 F MRI probe to evaluate dopaminergic presynaptic function in the striatum. To select candidates for 19 F MRI probes, we investigated the following eight non-radioactive fluorine-containing dopaminergic agents: fluorodopa (F-DOPA), F-tyrosine, haloperidol, GBR13069 duhydrochloride, GBR12909 duhydrochloride, 3-bis-(4-fluorophenyl) methoxytropane hydrochloride, flupenthixol, and fenfluramine. In 19 F nuclear magnetic resonance measurements, F-tyrosine and F-DOPA displayed a relatively higher signal-to-noise ratio value in brain homogenates than in others. F-DOPA, but not F-tyrosine, induced the rotational behavior in a 6-hydroxydopamine (6-OHDA)-induced hemiparkinsonian rat model. In addition, a significantly high amount of F-DOPA accumulated in the ipsilateral striatum of hemiparkinsonian rats after the injection. We performed 19 F MRI in PC12 cells and isolated rat brain using a 7T MR scanner. Our findings suggest that F-DOPA is a promising 19 F MRI probe for evaluating dopaminergic presynaptic function in the striatum of hemiparkinsonian rats. © 2016 Wiley Periodicals, Inc.


Asunto(s)
Cuerpo Estriado/diagnóstico por imagen , Dihidroxifenilalanina/análogos & derivados , Modelos Animales de Enfermedad , Dopamina/fisiología , Imagen por Resonancia Magnética con Fluor-19/métodos , Enfermedad de Parkinson/diagnóstico por imagen , Animales , Cuerpo Estriado/metabolismo , Dihidroxifenilalanina/metabolismo , Neuronas Dopaminérgicas/fisiología , Flúor/metabolismo , Radioisótopos de Flúor/metabolismo , Masculino , Células PC12 , Enfermedad de Parkinson/metabolismo , Ratas , Ratas Wistar
12.
Stud Health Technol Inform ; 220: 215-8, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27046581

RESUMEN

Laparoscopic surgery has become a widely performed surgery as it is one of the most common minimally invasive surgeries. Doctors perform the surgery by manipulating thin and long surgical instruments precisely with the assistance of laparoscopic video with limited field of view. The power control of the instruments' tip is especially very important, because excessive power may damage internal organs. The training of this surgical technique is mainly supervised by an expert in hands-on coaching program. However, it is difficult for the experts to spend sufficient time for coaching. Therefore, we aim to teach the expert's hand movements in laparoscopic surgery to trainees using VR-based simulator, which is equipped with a guidance force display device. To realize the system, we propose two haptic training approaches for transferring the expert's hand movements to the trainee. One is active training, and the other is passive training. The former approach shows the expert's movements only when the trainee makes large errors while the latter shows the expert's movements continuously. In this study, we validate the applicability of these approaches through tasks in VR laparoscopic surgery training simulator, and identify the differences between these approaches.


Asunto(s)
Competencia Clínica , Enseñanza Mediante Simulación de Alta Fidelidad/métodos , Laparoscopía/educación , Laparoscopía/instrumentación , Cirugía Asistida por Computador/instrumentación , Tacto , Instrucción por Computador/métodos , Diseño de Equipo , Análisis de Falla de Equipo , Humanos , Laparoscopía/métodos , Cirugía Asistida por Computador/métodos , Interfaz Usuario-Computador
13.
Stud Health Technol Inform ; 220: 403-6, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27046613

RESUMEN

In this paper, we report a result of an experiment of a field trial of our network-based minimally invasive surgery simulator. In our previous paper, we proposed a network-based visuohaptic surgery training system for laparoscopic surgery. In addition, we proposed a volume-based haptic communication approach, which allows participants at remote sites on the network to simultaneously interact with the same target object in virtual environments presented by multi-level computer performance systems, by only exchanging a small set of manipulation parameters for the target object and additional packet for synchronization of status of binary tree and deformation of shared volume model. We implemented the approach into our network-based surgery simulator, and field trial of the simulator at three locations was performed.


Asunto(s)
Redes de Comunicación de Computadores/instrumentación , Instrucción por Computador/instrumentación , Laparoscopía/instrumentación , Procedimientos Quirúrgicos Mínimamente Invasivos/instrumentación , Robótica/instrumentación , Cirugía Asistida por Computador/instrumentación , Sistemas de Computación , Diseño de Equipo , Análisis de Falla de Equipo , Imagenología Tridimensional/instrumentación , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Robótica/métodos , Telemedicina , Tacto , Interfaz Usuario-Computador
14.
Ageing Res Rev ; 30: 85-94, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-26772439

RESUMEN

The formation of senile plaques followed by the deposition of amyloid-ß is the earliest pathological change in Alzheimer's disease. Thus, the detection of senile plaques remains the most important early diagnostic indicator of Alzheimer's disease. Amyloid imaging is a noninvasive technique for visualizing senile plaques in the brains of Alzheimer's patients using positron emission tomography (PET) or magnetic resonance imaging (MRI). Because fluorine-19 ((19)F) displays an intense nuclear magnetic resonance signal and is almost non-existent in the body, targets are detected with a higher signal-to-noise ratio using appropriate fluorinated contrast agents. The recent introduction of high-field MRI allows us to detect amyloid depositions in the brain of living mouse using (19)F-MRI. So far, at least three probes have been reported to detect amyloid deposition in the brain of transgenic mouse models of Alzheimer's disease; (E,E)-1-fluoro-2,5-bis-(3-hydroxycarbonyl-4-hydroxy)styrylbenzene (FSB), 1,7-bis(4'-hydroxy-3'-trifluoromethoxyphenyl)-4-methoxycarbonylethyl-1,6-heptadiene3,5-dione (FMeC1, Shiga-Y5) and 6-(3',6',9',15',18',21'-heptaoxa-23',23',23'-trifluorotricosanyloxy)-2-(4'-dimethylaminostyryl)benzoxazole (XP7, Shiga-X22). This review presents the recent advances in amyloid imaging using (19)F-MRI, including our own studies.


Asunto(s)
Enfermedad de Alzheimer/diagnóstico por imagen , Amiloidosis/diagnóstico por imagen , Flúor , Imagen por Resonancia Magnética/métodos , Tomografía de Emisión de Positrones/métodos , Animales , Humanos , Imagen Multimodal/métodos , Placa Amiloide/diagnóstico por imagen , Estirenos
15.
Int J Nanomedicine ; 10: 4137-47, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26203241

RESUMEN

Hepatocellular carcinoma (HCC) is one of the most intractable and lethal cancers; most cases are diagnosed at advanced stages with underlying liver dysfunction and are frequently resistant to conventional chemotherapy and radiotherapy. The development of tumor-targeting systems may improve treatment outcomes. Nanomedicine platforms are of particular interest for enhancing chemotherapeutic efficiency, and they include polymeric micelles, which enable targeting of multiple drugs to solid tumors, including imaging and therapeutic agents. This allows concurrent diagnosis, targeting strategy validation, and efficacy assessment. We used polymeric micelles containing the T1-weighted magnetic resonance imaging contrast agent gadolinium-diethylenetriaminpentaacetic acid (Gd-DTPA) and the parent complex of the anticancer drug oxaliplatin [(1,2-diaminocyclohexane)platinum(II) (DACHPt)] for simultaneous imaging and therapy in an orthotopic rat model of HCC. The Gd-DTPA/DACHPt-loaded micelles were injected into the hepatic artery, and magnetic resonance imaging performance and antitumor activity against HCC, as well as adverse drug reactions were assessed. After a single administration, the micelles achieved strong and specific tumor contrast enhancement, induced high levels of tumor apoptosis, and significantly suppressed tumor size and growth. Moreover, the micelles did not induce severe adverse reactions and significantly improved survival outcomes in comparison to oxaliplatin or saline controls. Our results suggest that Gd-DTPA/DACHPt-loaded micelles are a promising approach for effective diagnosis and treatment of advanced HCC.


Asunto(s)
Antineoplásicos , Carcinoma Hepatocelular , Neoplasias Hepáticas Experimentales , Imagen por Resonancia Magnética/métodos , Micelas , Platino (Metal) , Animales , Antineoplásicos/química , Antineoplásicos/uso terapéutico , Carcinoma Hepatocelular/tratamiento farmacológico , Carcinoma Hepatocelular/mortalidad , Neoplasias Hepáticas Experimentales/tratamiento farmacológico , Neoplasias Hepáticas Experimentales/mortalidad , Platino (Metal)/química , Platino (Metal)/uso terapéutico , Ratas
16.
Biochem Biophys Rep ; 4: 357-368, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29124225

RESUMEN

Modulation of abnormal amyloid ß (Aß) aggregation is considered to be a potential therapeutic target for Alzheimer's disease (AD). Recent in vitro and in vivo experiments suggest that inhibition of Aß aggregation by curcumin would exert favorable effects for preventing or treating AD. We have previously synthesized a series of novel curcumin derivatives. In this study, we investigated the effects of our curcumin derivatives on Aß aggregation and the cell toxicities of Aß aggregates. According to sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) profiles, 14 of 41 compounds showed a significant increase in the densities of the bands of Aß (1-42) by incubation during the aggregation process relative to those of Aß (1-42) prepared in the presence of the vehicle control. Of the 14 compounds, four compounds additionally reduced cell toxicity of the Aß aggregates by incubation during the aggregation process. A significant positive correlation was observed between the cell viability and densities of the bands at ranges of 15-20, 20-37, 37-75, and 75-200 kDa in SDS-PAGE. On the basis of these results, we propose four curcumin derivatives with potential for preventing AD. These curcumin derivatives exhibited high inhibitory effects on Aß aggregation and induced the formation of lower molecular size Aß species that have weaker cell toxicity. These compounds may exert therapeutic effects on AD in future in vivo studies.

17.
Surg Today ; 45(9): 1173-8, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25297930

RESUMEN

PURPOSE: Percutaneous thermal ablation is used for treating hepatic tumors. Recent advances in laparoscopy and imaging modalities have led to the development of a novel image-guided minimally invasive loco-regional treatment. The aim of this trial was to apply laparoscopic assistance to magnetic resonance (MR) image-guided thermoablation instead of ultrasonography, because of its various advantages. METHODS: Patients with hepatic tumors and liver cirrhosis underwent magnetic resonance (MR) image-guided laparoscopic microwave coagulation therapy using a borescope and endoscopic forceps. Six cases of laparoscopic microwave coagulation treatment using MR image guidance were successfully performed between January 2000 and December 2008. Tumors were detected, punctured, and ablated in an open-configured MR scanner. A total of nine hepatocellular carcinoma nodules were preoperatively identified in S3, S5 and S6 (mean diameter = 20.8 ± 5.4 mm). RESULTS: MR-guided microwave coagulation was laparoscopically achieved in all patients without any significant complications that required invasive treatment. The mean length of the operation was 275.3 ± 60.5 min, and the mean postsurgical hospital stay was 10.0 ± 2.3 days. Postoperative confirmation scanning was performed without moving the patients. CONCLUSION: MR-guided laparoscopic microwave coagulation therapy is an effective treatment for hepatic tumors adjacent to other organs, as it allows for more accurate detection of lesions and for tumors to be treated safely while avoiding adjacent organs. It is less invasive than conventional procedures, because the MR real-time guidance enabled continuous monitoring throughout the procedure.


Asunto(s)
Técnicas de Ablación/métodos , Carcinoma Hepatocelular/cirugía , Laparoscopía/métodos , Cirrosis Hepática/cirugía , Neoplasias Hepáticas/cirugía , Imagen por Resonancia Magnética/métodos , Microondas/uso terapéutico , Cirugía Asistida por Computador/métodos , Anciano , Femenino , Humanos , Tiempo de Internación , Masculino , Persona de Mediana Edad , Tempo Operativo , Resultado del Tratamiento
18.
Neurobiol Aging ; 36(1): 201-10, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25179227

RESUMEN

Recent evidence supports the amyloid cascade hypothesis that a pathological change of amyloid ß (Aß) in the brain is an initiating event in Alzheimer's disease (AD). Accordingly, modulating the abnormal Aß aggregation is considered a potential therapeutic target in AD. Curcumin, a low-molecular-weight polyphenol derived from the well-known curry spice turmeric, has shown favorable effects on preventing or treating AD pathology. The present study investigated the effects of curcumin and 2 novel curcumin derivatives, FMeC1 and FMeC2, on AD pathology in APPswe/PS1dE9 double transgenic mice. Mice fed a chow diet that contained FMeC1 for 6 months showed a reduction in insoluble Aß deposits and glial cell activity together with reduced cognitive deficits, compared to animals receiving a control diet or with curcumin or FMeC2 in their diet. Both curcumin and FMeC1 modulated the formation of Aß aggregates; however, only FMeC1 significantly attenuated the cell toxicity of Aß. These results indicate that FMeC1 may have potential for preventing AD.


Asunto(s)
Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/prevención & control , Péptidos beta-Amiloides/metabolismo , Encéfalo/metabolismo , Curcumina/análogos & derivados , Curcumina/farmacología , Presenilina-1/metabolismo , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/psicología , Péptidos beta-Amiloides/genética , Péptidos beta-Amiloides/toxicidad , Animales , Cognición , Curcumina/administración & dosificación , Curcumina/química , Ratones Endogámicos C57BL , Ratones Transgénicos , Terapia Molecular Dirigida , Neuroglía/fisiología , Presenilina-1/genética , Agregación Patológica de Proteínas/genética , Agregación Patológica de Proteínas/prevención & control
19.
Comput Biol Med ; 53: 42-7, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25127407

RESUMEN

BACKGROUND: Our goal was to develop a three-dimensional finite element model that enables dynamic analysis of needle insertion for soft materials. To demonstrate large deformation and fracture, we used the arbitrary Lagrangian-Eulerian (ALE) method for fluid analysis. We performed ALE-based finite element analysis for 3% agar gel and three types of copper needle with bevel tips. METHODS: To evaluate simulation results, we compared the needle deflection and insertion force with corresponding experimental results acquired with a uniaxial manipulator. We studied the shear stress distribution of agar gel on various time scales. RESULTS: For 30°, 45°, and 60°, differences in deflections of each needle between both sets of results were 2.424, 2.981, and 3.737mm, respectively. For the insertion force, there was no significant difference for mismatching area error (p<0.05) between simulation and experimental results. CONCLUSIONS: Our results have the potential to be a stepping stone to develop pre-operative surgical planning to estimate an optimal needle insertion path for MR image-guided microwave coagulation therapy and for analyzing large deformation and fracture in biological tissues.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Modelos Biológicos , Agujas , Cirugía Asistida por Computador/métodos , Ultrasonografía Intervencional/métodos , Fenómenos Biomecánicos , Simulación por Computador , Análisis de Elementos Finitos , Imagen por Resonancia Magnética/instrumentación , Fantasmas de Imagen , Ultrasonografía Intervencional/instrumentación
20.
PLoS One ; 9(7): e102132, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25007334

RESUMEN

Morphological imaging precedes lesion-specific visualization in magnetic resonance imaging (MRI) because of the superior ability of this technique to depict tissue morphology with excellent spatial and temporal resolutions. To achieve lesion-specific visualization of tumors by MRI, we investigated the availability of a novel polymer-based tracer. Although the 13C nucleus is a candidate for a detection nucleus because of its low background signal in the body, the low magnetic resonance sensitivity of the nucleus needs to be resolved before developing a 13C-based tracer. In order to overcome this problem, we enriched polyethylene glycol (PEG), a biocompatible polymer, with 13C atoms. 13C-PEG40,000 (13C-PEG with an average molecular weight of 40 kDa) emitted a single 13C signal with a high signal-to-noise ratio due to its ability to maintain signal sharpness, as was confirmed by in vivo investigation, and displayed a chemical shift sufficiently distinct from that of endogenous fat. 13C-PEG40,000 intravenously injected into mice showed long retention in circulation, leading to its effective accumulation in tumors reflecting the well-known phenomenon that macromolecules accumulate in tumors because of leaky tumor capillaries. These properties of 13C-PEG40,000 allowed visualization of tumors in mice by 13C spectroscopic imaging. These findings suggest that a technique based on 13C-PEG is a promising strategy for tumor detection.


Asunto(s)
Materiales Biocompatibles/administración & dosificación , Isótopos de Carbono/metabolismo , Imagen por Resonancia Magnética/métodos , Neoplasias/patología , Polietilenglicoles/química , Animales , Materiales Biocompatibles/química , Materiales Biocompatibles/metabolismo , Línea Celular Tumoral , Humanos , Ratones , Trasplante de Neoplasias , Relación Señal-Ruido
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