Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 45
Filtrar
1.
Sensors (Basel) ; 24(5)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38475154

RESUMO

Stroke survivors with hemiparesis require extensive home-based rehabilitation. Deep learning-based classifiers can detect actions and provide feedback based on patient data; however, this is difficult owing to data sparsity and heterogeneity. In this study, we investigate data augmentation and model training strategies to address this problem. Three transformations are tested with varying data volumes to analyze the changes in the classification performance of individual data. Moreover, the impact of transfer learning relative to a pre-trained one-dimensional convolutional neural network (Conv1D) and training with an advanced InceptionTime model are estimated with data augmentation. In Conv1D, the joint training data of non-disabled (ND) participants and double rotationally augmented data of stroke patients is observed to outperform the baseline in terms of F1-score (60.9% vs. 47.3%). Transfer learning pre-trained with ND data exhibits 60.3% accuracy, whereas joint training with InceptionTime exhibits 67.2% accuracy under the same conditions. Our results indicate that rotational augmentation is more effective for individual data with initially lower performance and subset data with smaller numbers of participants than other techniques, suggesting that joint training on rotationally augmented ND and stroke data enhances classification performance, particularly in cases with sparse data and lower initial performance.


Assuntos
Redes Neurais de Computação , Acidente Vascular Cerebral , Humanos , Paresia , Sobreviventes
2.
Sensors (Basel) ; 24(1)2023 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-38203072

RESUMO

Measuring the daily use of an affected limb after hospital discharge is crucial for hemiparetic stroke rehabilitation. Classifying movements using non-intrusive wearable sensors provides context for arm use and is essential for the development of a home rehabilitation system. However, the movement classification of stroke patients poses unique challenges, including variability and sparsity. To address these challenges, we collected movement data from 15 hemiparetic stroke patients (Stroke group) and 29 non-disabled individuals (ND group). The participants performed two different tasks, the range of motion (14 movements) task and the activities of daily living (56 movements) task, wearing five inertial measurement units in a home setting. We trained a 1D convolutional neural network and evaluated its performance for different training groups: ND-only, Stroke-only, and ND and Stroke jointly. We further compared the model performance with data augmentation from axis rotation and investigated how the performance varied based on the asymmetry of movements. The joint training of ND + Stroke yielded an increased F1-score by a margin of 31.6% and 10.6% compared to ND-only training and Stroke-only training, respectively. Data augmentation further enhanced F1-scores across all conditions by an average of 11.3%. Finally, asymmetric movements decreased the F1-score by 25.9% compared to symmetric movements in the Stroke group, indicating the importance of asymmetry in movement classification.


Assuntos
Aprendizado Profundo , Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Dispositivos Eletrônicos Vestíveis , Humanos , Atividades Cotidianas , Acidente Vascular Cerebral/diagnóstico
3.
Medicine (Baltimore) ; 101(40): e30912, 2022 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-36221340

RESUMO

RATIONALE: Traumatic lateral atlantoaxial dislocation (AAD) combined with an odontoid fracture is extremely rare. The standards applicable to management of the traumatic lateral AAD are still in flux due to the infrequency of this injury. PATIENT CONCERNS: We present a unique case of traumatic lateral AAD combined with a type II odontoid fracture in a patient with ankylosing spondylitis (AS). DIAGNOSIS: Spinal computed tomography showed ankylosis of the entire spine from the sacroiliac joint to the cervical spine. On the cervical X-ray the head was rotated to the right with anterior subluxation of the C1 and odontoid tip relative to C2. The coronal computed tomography (CT) scan also revealed left lateral dislocation of C1 on C2 with a horizontal translation of the odontoid tip. On the axial and sagittal CT scan, the left C1 lateral mass was displaced anteriorly and locked by C2 body. INTERVENTIONS: We performed occipito-cervical fusion (OCF) after successful manual reduction under general anesthesia. OUTCOMES: The patient's recovery from surgery was uneventful and without complication. At the 3 year follow-up the patient was asymptomatic and reportedly satisfied with the surgery. LESSONS: Traumatic AAD with an odontoid fracture is an exceedingly uncommon cervical spine injury. A lateral subluxation with a type II odontoid fracture in a patient with AS is rarer still, so much so that this type of subluxation was not classifiable using any of the previously developed classification systems. In this patient with AS, posterior OCF with internal fixation was necessary to avoid hardware failure, particularly in light of the intensive stress caused by AS.


Assuntos
Articulação Atlantoaxial , Fraturas Ósseas , Luxações Articulares , Lesões do Pescoço , Processo Odontoide , Fraturas da Coluna Vertebral , Fusão Vertebral , Espondilite Anquilosante , Articulação Atlantoaxial/diagnóstico por imagem , Articulação Atlantoaxial/lesões , Articulação Atlantoaxial/cirurgia , Vértebras Cervicais/cirurgia , Fraturas Ósseas/complicações , Humanos , Luxações Articulares/complicações , Luxações Articulares/diagnóstico por imagem , Luxações Articulares/cirurgia , Lesões do Pescoço/complicações , Processo Odontoide/diagnóstico por imagem , Processo Odontoide/lesões , Processo Odontoide/cirurgia , Fraturas da Coluna Vertebral/complicações , Fraturas da Coluna Vertebral/diagnóstico por imagem , Fusão Vertebral/métodos , Espondilite Anquilosante/complicações
4.
RSC Adv ; 12(16): 9698-9703, 2022 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-35424952

RESUMO

Transition metal compounds based on silver (Ag) and palladium (Pd) are extensively used as catalysts in the petrochemical industries. The catalytic activities of Ag and Pd decrease over time and hence need to be discarded. The recovery of elements like Ag from waste catalyst is essential because of its limited availability and cost, and it is environmentally beneficial with regards to recycling. In this study, Pd and Ag were leached from waste catalyst providing an alternative source suitable for a Ag paste electrode. Through an efficient reduction process, AgCl particles were obtained which serve as a precursor to synthesize Ag using ammonia as the solvent. The obtained Ag was fabricated to Ag paste by using mixed dispersion and solvent. The electrical resistivity of the Ag paste was recorded as 6.14 µΩ cm at 417 °C in a hydrogen atmosphere.

5.
Medicine (Baltimore) ; 100(49): e28122, 2021 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-34889272

RESUMO

ABSTRACT: The treatment of an atlas burst fracture depends on whether transverse atlantal ligament (TAL) injury is present. We compared the radiologic parameters associated with the presence of a TAL injury as detected using magnetic resonance imaging (MRI), and verified whether the lateral mass displacement (LMD) criteria currently used to diagnose TAL injuries in atlas burst fractures are reliable or need revision.Thirty patients who presented with isolated atlas burst fractures were included in this retrospective observational study. We measured radiologic parameters, including LMD, atlanto-dental interval, basion-dens interval, internal lateral mass displacement, and external lateral mass displacement, in each patient at the time of initial presentation. The presence of TAL injury was evaluated using MRI. We compared the radiologic parameters and characteristics of patients who presented with TAL injury. We also determined the sensitivity and specificity of an LMD test to accurately diagnose TAL injury based on MRI. Finally, we compared the radiologic parameters according to the presence of surgical treatment and patient union status.Twenty patients presented with an intact TAL, while 10 patients had a TAL injury on MRI. LMD was significantly higher in patients with TAL injury (9.61 vs 3.73 mm, P < .001). In multivariable logistic regression analysis, LMD was also significantly higher in patients with TAL injury. The sensitivity and specificity of LMD for diagnosing TAL injury based on MRI in patients with isolated C1 fractures were 90% and 100%, respectively. The incidence of an LMD greater than 8.1 mm was statistically higher in patients than in those without TAL injury (90% vs 0%, P < .001).Nine patients underwent surgery for isolated atlas burst fractures, and 21 did not. LMD (9.56 vs 4.03 mm, P < .001) and fracture gap (7.96 vs 4.01 mm, P < .001) were significantly higher in patients who underwent surgery.Among the various radiologic parameters, LMD closely correlated with the presence of TAL injury, as patients with an LMD greater than 8.1 mm were more likely to have a TAL injury in the case of atlas burst fractures. LMD is a good method for predicting the presence of TAL injury if MRI is not available.


Assuntos
Articulação Atlantoaxial/diagnóstico por imagem , Articulação Atlantoccipital/diagnóstico por imagem , Fraturas Ósseas/diagnóstico por imagem , Ligamentos Articulares/diagnóstico por imagem , Imageamento por Ressonância Magnética/estatística & dados numéricos , Adulto , Idoso , Articulação Atlantoaxial/lesões , Articulação Atlantoccipital/lesões , Feminino , Humanos , Ligamentos Articulares/lesões , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
6.
Medicine (Baltimore) ; 100(49): e28146, 2021 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-34889281

RESUMO

INTRODUCTION: Posterior epidural migration of lumbar disc fragment (PEMLDF) is a very rare condition that may lead to a serious neurological deficit such as cauda equina syndrome. Magnetic resonance imaging (MRI) findings can often result in cases of PEMLDF being misdiagnosed as extradural masses of other origin or epidural hematomas. In this study, we reported four additional cases of PEMLDF and reviewed the relevant literature. PATIENT CONCERNS: We present four patients with PEMLDF. The mean age of the patients was 53.5 years. Two patients suffered from cauda equine syndrome, and the other two patients complained of radiculopathy. DIAGNOSIS: The MRI findings in each case showed masses with slightly high signal intensity in T2-weighted images, as well as heterogenous and peripheral rim enhancement after contrast enhancement. In some patients there was a tract-like enhancement extending from the outer aspect of the disc to the posterolateral epidural space. A definitive diagnosis was made intraoperatively. INTERVENTIONS: We performed laminectomy and discectomy in all patients. OUTCOMES: The PEMLDF patients with radiculopathy had no complaints of weakness or pain after surgery. Both patients with cauda equine syndrome showed a total recovery post-surgery. CONCLUSIONS: Early diagnosis and treatment via laminectomy and discectomy is critical to achieving the best postoperative outcomes. Understanding the patient's history, recognizing the similar signal intensity of the mass and intervertebral disc on MRI scans, and looking for peripheral rim enhancement, are the keys to the correct diagnosis of PEMLDF.


Assuntos
Síndrome da Cauda Equina/diagnóstico , Espaço Epidural/diagnóstico por imagem , Deslocamento do Disco Intervertebral/diagnóstico por imagem , Vértebras Lombares/diagnóstico por imagem , Radiculopatia/diagnóstico , Idoso , Animais , Síndrome da Cauda Equina/etiologia , Síndrome da Cauda Equina/cirurgia , Discotomia , Feminino , Cavalos , Humanos , Disco Intervertebral , Deslocamento do Disco Intervertebral/complicações , Deslocamento do Disco Intervertebral/cirurgia , Laminectomia , Vértebras Lombares/cirurgia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Radiculopatia/etiologia
7.
Medicine (Baltimore) ; 100(16): e25587, 2021 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-33879717

RESUMO

RATIONALE: Tarlov or perineurial cysts are nerve root lesions often found in the sacral region. Most perineural cysts (PCs) remain asymptomatic throughout a patient's life. While their pathogenesis is still unclear, trauma resulting in hemorrhaging into subarachnoid space has been put forward as a possible cause of these cysts. Recently, we worked with a patient experiencing symptomatic PCs after spontaneous subarachnoid hemorrhage. PATIENT CONCERNS: A 45-year-old man had a coil embolization procedure performed after being diagnosed with a subarachnoid hemorrhage from a ruptured anterior communicating artery. His symptoms were relieved after the procedure, but 7 days later he reported worsening pain in the left perineal area. The pain was intermittent at its onset and exacerbated by sitting, walking, and coughing. DIAGNOSES: Two weeks after the embolization procedure, a lumbar spine MRI revealed 2 PCs at the S1 and S2 level affecting the left S2 root with high signal intensity in T2 and T1 images, suggestive of bleeding within the cyst. INTERVENTIONS: We operated using a posterior approach. Cyst fenestration was done after S1 laminectomy. We aspirated approximately 1 cc of old blood. OUTCOMES: His pain was relieved immediately after cyst removal and no neurologic deterioration occurred during the postoperative period. LESSONS: Subarachnoid hemorrhage can be the source of the development of pain from asymptomatic PCs, making them symptomatic. Surgical extirpation is 1 treatment option for these symptomatic PCs.


Assuntos
Embolização Terapêutica/efeitos adversos , Complicações Pós-Operatórias/etiologia , Hemorragia Subaracnóidea/cirurgia , Cistos de Tarlov/etiologia , Aneurisma Roto/complicações , Aneurisma Roto/cirurgia , Embolização Terapêutica/métodos , Humanos , Aneurisma Intracraniano/complicações , Aneurisma Intracraniano/cirurgia , Laminectomia/métodos , Masculino , Pessoa de Meia-Idade , Períneo/patologia , Períneo/cirurgia , Complicações Pós-Operatórias/cirurgia , Hemorragia Subaracnóidea/etiologia , Cistos de Tarlov/cirurgia
8.
Rehabil Nurs ; 2020 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-32304482

RESUMO

PURPOSE: This preliminary study aimed to compare the outcomes of an occupational therapist-led and a nurse-led computerized cognitive training (CCT) for mild cognitive impairment (MCI) in older adults. DESIGN: A single-blind randomized controlled trial was performed. METHODS: Participants 65 years of age and older with MCI were randomly assigned to a group led by an occupational therapist or by a nurse. Both groups received CCT for 4 weeks. FINDINGS: Six participants in the occupational therapist-led group and nine in the nurse-led group completed CCT. The nurse-led group showed significant improvement in scores on the Seoul Verbal Learning Test-Elderly's version immediate recall scores (p = .030) and the Korean-Boston Naming Test (p = .012). CONCLUSIONS: Nurse-led CCT demonstrated improvement in some language and memory areas in older adults with MCI. CLINICAL RELEVANCE: This study supports the idea of educating nurses to use a CCT program for treating older adults with MCI to improve their cognitive function.

9.
Medicine (Baltimore) ; 98(44): e17695, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31689795

RESUMO

RATIONALE: Aneurysmal bone cyst (ABC) is a benign, reactive, non-neoplastic, proliferative, highly vascular osseous lesion. Because of the rarity of aggressive ABC cases, diagnostic and treatment protocols remain controversial and problematic. Treatment of ABC includes surgery, radiotherapy, selective arterial embolization (SAE), and a combination of these modalities. Successful outcomes have been reported, but the technical requirements and complications of each modality are quite different. We report the clinical, radiological, and therapeutic aspects of ABC of the thoracic spine in an adolescent who was treated by circumferential fusion, and we review the published literature. PATIENT CONCERNS: An 18-year-old boy was transferred to our hospital complaining of a 2-month history of neck pain. DIAGNOSIS: ABC of the thoracic spine INTERVENTIONS:: Six days after SAE, T1 corpectomy was performed via an anterior approach. We performed the operation using the posterior approach 1 week after the anterior approach. Histopathological examination confirmed the diagnosis of ABC. OUTCOMES: No neurologic deterioration occurred during the postoperative period. Follow-up X-rays 2 year postoperative showed good bony fusion and alignment. LESSONS: Primary ABC of the spine is a benign lesion with a potential to be locally aggressive and a high rate of local recurrence. The optimal treatment of thoracic lesions is challenging due to their proximity to the spinal cord and nerve roots, and their frequent association with deformity. Surgical resection/curettage, SAE, and radiotherapy can be used alone or in combination. Complete exposure and resection is crucial to avoid the recurrence. Circumferential fusion and reconstruction of stability are also important for the treatment of thoracic ABC, especially in adolescent patient.


Assuntos
Cistos Ósseos Aneurismáticos/cirurgia , Fusão Vertebral/métodos , Vértebras Torácicas/cirurgia , Adolescente , Humanos , Masculino
10.
J Neurosci ; 39(46): 9237-9250, 2019 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-31582527

RESUMO

Humans predict the sensory consequences of motor commands by learning internal models of the body and of environment perturbations. When facing a sensory prediction error, should we attribute this error to a change in our body, and update the body internal model, or to a change in the environment? In the latter case, should we update an existing perturbation model or create a new model? Here, we propose that a decision-making process compares the models' prediction errors, weighted by their precisions, to select and update either the body model or an existing perturbation model. When no model can predict a perturbation, a new perturbation model is created and selected. When a model is selected, both the prediction's mean estimate and uncertainty are updated to minimize future prediction errors and to increase the precision of the predictions. Results from computer simulations, which we verified in an arm visuomotor adaptation experiment with subjects of both sexes, account for short aftereffects and large savings after adaptation to large, but not small, perturbations. Results also clarify previous data in the absence of errors (error-clamp): motor memories show an initial lack of decay after a large perturbation, but gradual decay after a small perturbation. Finally, qualitative individual differences in adaptation were explained by subjects selecting and updating either the body model or a perturbation model. Our results suggest that motor adaptation belongs to a general class of learning according to which memories are created when no existing memories can predict sensory data accurately and precisely.SIGNIFICANCE STATEMENT When movements are followed by unexpected outcomes, such as following the introduction of a visuomotor or a force field perturbation, or the sudden removal of such perturbations, it is unclear whether the CNS updates existing memories or creates new memories. Here, we propose a novel model of adaptation, and investigate, via computer simulations and behavioral experiments, how the amplitude and schedule of the perturbation, as well as the characteristics of the learner, lead to the selection and update of existing memories or the creation of new memories. Our results provide insights into a number of puzzling and contradictory motor adaptation data, as well as into qualitative individual differences in adaptation.


Assuntos
Adaptação Fisiológica , Retroalimentação Sensorial , Memória/fisiologia , Desempenho Psicomotor , Adulto , Feminino , Humanos , Masculino , Modelos Neurológicos , Atividade Motora , Adulto Jovem
11.
Sci Rep ; 8(1): 16483, 2018 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-30405177

RESUMO

Sensory prediction errors are thought to update memories in motor adaptation, but the role of performance errors is largely unknown. To dissociate these errors, we manipulated visual feedback during fast shooting movements under visuomotor rotation. Participants were instructed to strategically correct for performance errors by shooting to a neighboring target in one of four conditions: following the movement onset, the main target, the neighboring target, both targets, or none of the targets disappeared. Participants in all conditions experienced a drift away from the main target following the strategy. In conditions where the main target was shown, participants often tried to minimize performance errors caused by the drift by generating corrective movements. However, despite differences in performance during adaptation between conditions, memory decay in a delayed washout block was indistinguishable between conditions. Our results thus suggest that, in visuomotor adaptation, sensory predictions errors, but not performance errors, update the slow, temporally stable, component of motor memory.


Assuntos
Adaptação Fisiológica , Retroalimentação Sensorial , Memória , Desempenho Psicomotor , Adulto , Feminino , Humanos , Masculino , Percepção Visual , Adulto Jovem
12.
Medicine (Baltimore) ; 96(36): e8022, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28885370

RESUMO

The aim of this study was to investigate the usefulness of titanium mesh cage as an interlaminar spacer combined with nitinol shape memory loop fixation in patients with atlantoaxial instability.From April 2009 to March 2017, among the patients with atlantoaxial instability, a total of 30 patients were treated by nitinol shape memory loop fixation combined with titanium mesh cage as a spacer. We retrospectively reviewed 30 enrolled patients. Successful fusion was determined as improvement of symptoms and radiologic findings of bone fusion. We also reviewed surgical complications, instrumentation failure, bony fusion rate, and posterior atlantodental interval (PADI).After surgery, the symptoms of all patients significantly improved. Successful fusion was documented throughout the follow-up period. Evidence of solid bridging bone was found, and no instability was seen on flexion-extension radiographs and callus formation on 3D cervical spine computed tomography (CT) 6 months postoperatively in all cases. No surgical complications were observed. No cases of instrumentation failure were observed. The mean PADI also improved significantly to 22.45 ±â€Š1.11 mm 6 months postoperatively compared with the preoperative value of 18.37 ±â€Š1.16 mm (P < .05).We obtained a good fusion rate by using titanium mesh cage spacer with nitinol shape memory alloy loop in patients with atlantoaxial instability. This technique can help surgeons in avoiding vertebral artery injury and reducing bleeding and operation time. Therefore, we suggest that titanium mesh cage spacer combined with nitinol shape memory alloy loop can be a good substitute of autograft for C1-C2 fusion in treating atlantoaxial instabilities.


Assuntos
Articulação Atlantoaxial/cirurgia , Vértebra Cervical Áxis/cirurgia , Atlas Cervical/cirurgia , Fixadores Internos , Instabilidade Articular/cirurgia , Fusão Vertebral/instrumentação , Adolescente , Adulto , Idoso , Articulação Atlantoaxial/diagnóstico por imagem , Vértebra Cervical Áxis/diagnóstico por imagem , Atlas Cervical/diagnóstico por imagem , Feminino , Seguimentos , Humanos , Imageamento Tridimensional , Instabilidade Articular/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Titânio , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Adulto Jovem
13.
Korean J Gastroenterol ; 69(4): 248-252, 2017 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-28449428

RESUMO

Peptic ulcer bleeding is treated using endoscopic hemostasis using clips or bands. Pancreas divisum (PD), a congenital anomaly of the pancreas, usually has no clinical symptoms; however, pancreatitis may occur if there are disturbances in the drainage of pancreatic secretions. We report an unusual case of PD accompanied by acute pancreatitis, following endoscopic band ligation for duodenal ulcer bleeding. A 48-year-old woman was admitted to our hospital due to melena. An upper endoscopy revealed a small ulcer with oozing adjacent minor papilla. An endoscopic band ligation was performed on this lesion. Acute pancreatitis developed suddenly 6 hours after the band ligation and improved dramatically after removal of the band. Magnetic resonance cholangiopancreatography was performed, revealing complete PD. Endoscopic band ligation is known as the effective method for peptic ulcer bleeding; however, it should be used carefully in duodenal ulcer bleeding near the minor duodenal papilla due to the possibility of PD.


Assuntos
Hemostase Endoscópica/efeitos adversos , Pâncreas/anormalidades , Pancreatite/diagnóstico , Úlcera Péptica Hemorrágica/terapia , Doença Aguda , Colangiopancreatografia por Ressonância Magnética , Endoscopia Gastrointestinal , Feminino , Humanos , Pessoa de Meia-Idade , Pâncreas/anatomia & histologia , Pancreatite/etiologia , Tomografia Computadorizada por Raios X
14.
Korean J Gastroenterol ; 69(4): 253-258, 2017 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-28449429

RESUMO

Although lymphoepithelial cysts (LECs) of the pancreas are benign lesions, most of them have been treated with surgical resection due to diagnostic difficulty. We report a 66-year-old woman diagnosed with pancreatic LECs. Abdominal ultrasound revealed two masses in the pancreas, which were not visible on the abdominal computed tomography. In an abdominal magnetic resonance imaging, pancreas lesions showed solid tumors, which revealed a low signal intensity on T1-, moderate high signal intensity on T2 weighted images, and homogeneous delayed enhancement in the portal venous phase. Endosonography (EUS) revealed two hypoechoic round masses measuring 1.5 cm and 4.5 cm in the body and tail of the pancreas, respectively. EUS-guided fine needle aspiration (FNA) revealed squamous cells, amorphous keratinous debris, and lymphocytes. The patient was diagnosed with LECs of the pancreas. For the duration of the follow-up period of two years, imaging studies were unchanged. EUS-FNA is useful in making a definite diagnosis and avoiding unnecessary surgery. This is the first case of pancreatic LECs diagnosed with EUS-FNA in Korea.


Assuntos
Cisto Pancreático/diagnóstico , Idoso , Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico , Feminino , Humanos , Imageamento por Ressonância Magnética , Pâncreas/diagnóstico por imagem , Pâncreas/patologia , Cisto Pancreático/diagnóstico por imagem , Cisto Pancreático/patologia , Tomografia Computadorizada por Raios X
15.
J Math Biol ; 75(5): 1101-1131, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28243721

RESUMO

In this paper, we study how chemotaxis affects the immune system by proposing a minimal mathematical model, a reaction-diffusion-advection system, describing a cross-talk between antigens and immune cells via chemokines. We analyze the stability and instability arising in our chemotaxis model and find their conditions for different chemotactic strengths by using energy estimates, spectral analysis, and bootstrap argument. Numerical simulations are also performed to the model, by using the finite volume method in order to deal with the chemotaxis term, and the fractional step methods are used to solve the whole system. From the analytical and numerical results for our model, we explain not only the effective attraction of immune cells toward the site of infection but also hypersensitivity when chemotactic strength is greater than some threshold.


Assuntos
Quimiotaxia/imunologia , Modelos Imunológicos , Animais , Antígenos/imunologia , Quimiocinas/imunologia , Simulação por Computador , Humanos , Modelos Lineares , Conceitos Matemáticos , Dinâmica não Linear
16.
Clin Endosc ; 50(2): 202-205, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27641150

RESUMO

Endoscopic closure techniques have been introduced for the repair of duodenal wall perforations that occur during endoscopic retrograde cholangiopancreatography (ERCP). We report a case of successful repair of a large duodenal wall perforation by using double endoscopic band ligation (EBL) and an endoclip. Lateral duodenal wall perforation occurred during ERCP in a 93-year-old woman with acute calculous cholangitis. We switched to a forward endoscope that had a transparent band apparatus. A 2.0-cm oval-shaped perforation was found at the lateral duodenal wall. We repaired the perforation by sequentially performing double EBL and endoclipping. The first EBL was performed at the proximal edge of the perforation orifice, and two-thirds of the perforation were repaired. The second EBL, which also included the contents covered under the first EBL, repaired the defect almost completely. Finally, to account for the possible presence of a residual perforation, an endoclip was applied at the distal end of the perforation. The detection and closure of the perforation were completed within 10 minutes. We suggest that double EBL is an effective method for closure.

17.
Korean J Spine ; 13(3): 139-143, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27799994

RESUMO

OBJECTIVE: There are also few studies demonstrating the relationship between ossification of nuchal ligament (ONL) and ossification of posterior longitudinal ligament (OPLL). We compared the prevalence, location, and type of OPLL between patients with ONL and matched patients without ONL.We also compared the bone mineral densities (BMDs) between the 2 groups. METHODS: total of 124 cervical ONL patients were enrolled in this study. The control group of 124 patients was matched with 124 patients with ONL by age and sex on a 1:1 basis to minimize confounding factors. We reviewed the prevalence, location, and type of OPLL in both groups. RESULTS: The prevalence of OPLL was almost 2.5 times greater in patients with ONL than those without ONL. The mean value of BMD in patients with ONL was greater at the lumbar spine (L1-L4) than in patients without ONL. The mean T score of the lumbar spine was 0.25±1.68 in the patients with ONL and -0.73±1.64 in the patients without ONL. CONCLUSION: The prevalence of OPLL in patients with ONL was significantly higher than in patients without ONL. Because ONL is innocuous and may be seen more readily than OPLL on simple cervical radiographs, clinicians should consider the possibility of coexisting OPLL when ONL, especially extensive ONL, is detected in patients with neck pain, radiculopathy, or myelopathy, to facilitate proper treatment.

18.
Neural Comput ; 28(4): 667-85, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26890347

RESUMO

Although scheduling multiple tasks in motor learning to maximize long-term retention of performance is of great practical importance in sports training and motor rehabilitation after brain injury, it is unclear how to do so. We propose here a novel theoretical approach that uses optimal control theory and computational models of motor adaptation to determine schedules that maximize long-term retention predictively. Using Pontryagin's maximum principle, we derived a control law that determines the trial-by-trial task choice that maximizes overall delayed retention for all tasks, as predicted by the state-space model. Simulations of a single session of adaptation with two tasks show that when task interference is high, there exists a threshold in relative task difficulty below which the alternating schedule is optimal. Only for large differences in task difficulties do optimal schedules assign more trials to the harder task. However, over the parameter range tested, alternating schedules yield long-term retention performance that is only slightly inferior to performance given by the true optimal schedules. Our results thus predict that in a large number of learning situations wherein tasks interfere, intermixing tasks with an equal number of trials is an effective strategy in enhancing long-term retention.


Assuntos
Adaptação Fisiológica/fisiologia , Simulação por Computador , Aprendizagem/fisiologia , Modelos Teóricos , Atividade Motora/fisiologia , Animais , Humanos , Retenção Psicológica/fisiologia
19.
Biointerphases ; 11(1): 011006, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26829967

RESUMO

Surface modification to improve the corrosion resistance and biocompatibility of the Mg-Al-Zn-Ca alloy was conducted via plasma electrolytic oxidation (PEO) in an electrolyte that included phosphate. Calcium phosphate can be easily induced on the surface of a PEO coating that includes phosphate in a physiological environment because Ca(2+) ions in body fluids can be combined with PO4 (3-). Cytotoxicity of the PEO coating formed in electrolytes with various amounts of Na3PO4 was identified. In particular, the effects that PEO films have upon oxidative stress and differentiation of osteoblast activity were studied. As the concentration of Na3PO4 in the electrolyte increased, the oxide layer was found to become thicker, which increased corrosion resistance. However, the PEO coating formed in electrolytes with over 0.2 M of added Na3PO4 exhibited more microcracks and larger pores than those formed in smaller Na3PO4 concentrations owing to a large spark discharge. A nonuniform oxide film that included more phosphate caused more cytotoxicity and oxidative stress, and overabundant phosphate content in the oxide layer interrupted the differentiation of osteoblasts. The corrosion resistance of the magnesium alloy and the thickness of the oxide layer were increased by the addition of Na3PO4 in the electrolyte for PEO treatment. However, excessive phosphate content in the oxide layer led to oxidative stress, which resulted in reduced cell viability and activity.


Assuntos
Ligas/química , Materiais Biocompatíveis/química , Eletrólitos/metabolismo , Osteoblastos/fisiologia , Fosfatos/metabolismo , Plasma/química , Propriedades de Superfície/efeitos dos fármacos , Diferenciação Celular , Oxirredução , Estresse Oxidativo
20.
Medicine (Baltimore) ; 95(6): e2797, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26871842

RESUMO

Cervical intradural disc herniation (IDH) is an extremely rare condition, comprising only 0.27% of all disc herniations. Three percent of IDHs occur in the cervical, 5% in the thoracic, and over 92% in the lumbar spinal canal. There have been a total of 31 cervical IDHs reported in the literature. The pathogenesis and imaging characteristics of IDH are not fully understood. A preoperative diagnosis is key to facilitating prompt intradural exploration in patients with ambivalent findings, as well as in preventing reoperation. The purpose of reporting our case is to remind clinicians to consider the possibility of cervical IDH during spinal manipulation therapy in patient with chronic neck pain.The patient signed informed consent for publication of this case report and any accompanying image. The ethical approval of this study was waived by the ethics committee of Chonbuk National University Hospital, because this study was case report and the number of patients was <3.A 32-year-old man was transferred our emergency department with progressive quadriparesis. He had no history of trauma, but had received physical therapy with spinal manipulation for chronic neck pain over the course of a month. The day prior, he had noticed neck pain and tingling in the bilateral upper and lower extremities during the manipulation procedure. The following day, he presented with bilateral weakness of all 4 extremities, which rendered him unable to walk. Neurological examination demonstrated a positive Hoffmann sign and ankle clonus bilaterally, hypoesthesia below the C5 dermatome, 3/5 strength in the bilateral upper extremities, and 2/5 strength in the lower extremities. This motor weakness was progressive, and he further complained of voiding difficulty.Urgent magnetic resonance imaging (MRI) of the cervical spine revealed large, central disc herniations at C4-C5 and C5-C6 that caused severe spinal cord compression and surrounding edema. We performed C4-C5-C6 anterior cervical discectomy and fusion.The patient's limb weakness improved rapidly within 1 day postoperatively, and he was discharged 4 weeks later. At his 12-month follow-up, the patient had recovered nearly full muscle power.We presented an extremely rare case of cervical IDH causing progressive quadriparesis after excessive spinal manipulation therapy. The presence of a "halo" and "Y-sign" were useful MRI markers for cervical IDH in this case.


Assuntos
Vértebras Cervicais , Deslocamento do Disco Intervertebral/complicações , Deslocamento do Disco Intervertebral/terapia , Manipulação da Coluna/efeitos adversos , Quadriplegia/etiologia , Adulto , Progressão da Doença , Humanos , Masculino , Cervicalgia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...