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1.
N Engl J Med ; 390(5): 409-420, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38294973

RESUMEN

BACKGROUND: Studies evaluating surgical-site infection have had conflicting results with respect to the use of alcohol solutions containing iodine povacrylex or chlorhexidine gluconate as skin antisepsis before surgery to repair a fractured limb (i.e., an extremity fracture). METHODS: In a cluster-randomized, crossover trial at 25 hospitals in the United States and Canada, we randomly assigned hospitals to use a solution of 0.7% iodine povacrylex in 74% isopropyl alcohol (iodine group) or 2% chlorhexidine gluconate in 70% isopropyl alcohol (chlorhexidine group) as preoperative antisepsis for surgical procedures to repair extremity fractures. Every 2 months, the hospitals alternated interventions. Separate populations of patients with either open or closed fractures were enrolled and included in the analysis. The primary outcome was surgical-site infection, which included superficial incisional infection within 30 days or deep incisional or organ-space infection within 90 days. The secondary outcome was unplanned reoperation for fracture-healing complications. RESULTS: A total of 6785 patients with a closed fracture and 1700 patients with an open fracture were included in the trial. In the closed-fracture population, surgical-site infection occurred in 77 patients (2.4%) in the iodine group and in 108 patients (3.3%) in the chlorhexidine group (odds ratio, 0.74; 95% confidence interval [CI], 0.55 to 1.00; P = 0.049). In the open-fracture population, surgical-site infection occurred in 54 patients (6.5%) in the iodine group and in 60 patients (7.3%) in the chlorhexidine group (odd ratio, 0.86; 95% CI, 0.58 to 1.27; P = 0.45). The frequencies of unplanned reoperation, 1-year outcomes, and serious adverse events were similar in the two groups. CONCLUSIONS: Among patients with closed extremity fractures, skin antisepsis with iodine povacrylex in alcohol resulted in fewer surgical-site infections than antisepsis with chlorhexidine gluconate in alcohol. In patients with open fractures, the results were similar in the two groups. (Funded by the Patient-Centered Outcomes Research Institute and the Canadian Institutes of Health Research; PREPARE ClinicalTrials.gov number, NCT03523962.).


Asunto(s)
Antiinfecciosos Locales , Clorhexidina , Fijación de Fractura , Fracturas Óseas , Yodo , Infección de la Herida Quirúrgica , Humanos , 2-Propanol/administración & dosificación , 2-Propanol/efectos adversos , 2-Propanol/uso terapéutico , Antiinfecciosos Locales/administración & dosificación , Antiinfecciosos Locales/efectos adversos , Antiinfecciosos Locales/uso terapéutico , Antisepsia/métodos , Canadá , Clorhexidina/administración & dosificación , Clorhexidina/efectos adversos , Clorhexidina/uso terapéutico , Etanol , Extremidades/lesiones , Extremidades/microbiología , Extremidades/cirugía , Yodo/administración & dosificación , Yodo/efectos adversos , Yodo/uso terapéutico , Cuidados Preoperatorios/efectos adversos , Cuidados Preoperatorios/métodos , Piel/microbiología , Infección de la Herida Quirúrgica/etiología , Infección de la Herida Quirúrgica/prevención & control , Fracturas Óseas/cirugía , Estudios Cruzados , Estados Unidos
2.
Eur J Orthop Surg Traumatol ; 34(2): 927-955, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37776392

RESUMEN

PURPOSE: The integration of artificial intelligence (AI) tools, such as ChatGPT, in clinical medicine and medical education has gained significant attention due to their potential to support decision-making and improve patient care. However, there is a need to evaluate the benefits and limitations of these tools in specific clinical scenarios. METHODS: This study used a case study approach within the field of orthopaedic surgery. A clinical case report featuring a 53-year-old male with a femoral neck fracture was used as the basis for evaluation. ChatGPT, a large language model, was asked to respond to clinical questions related to the case. The responses generated by ChatGPT were evaluated qualitatively, considering their relevance, justification, and alignment with the responses of real clinicians. Alternative dialogue protocols were also employed to assess the impact of additional prompts and contextual information on ChatGPT responses. RESULTS: ChatGPT generally provided clinically appropriate responses to the questions posed in the clinical case report. However, the level of justification and explanation varied across the generated responses. Occasionally, clinically inappropriate responses and inconsistencies were observed in the generated responses across different dialogue protocols and on separate days. CONCLUSIONS: The findings of this study highlight both the potential and limitations of using ChatGPT in clinical practice. While ChatGPT demonstrated the ability to provide relevant clinical information, the lack of consistent justification and occasional clinically inappropriate responses raise concerns about its reliability. These results underscore the importance of careful consideration and validation when using AI tools in healthcare. Further research and clinician training are necessary to effectively integrate AI tools like ChatGPT, ensuring their safe and reliable use in clinical decision-making.


Asunto(s)
Fracturas del Cuello Femoral , Procedimientos Ortopédicos , Masculino , Humanos , Persona de Mediana Edad , Inteligencia Artificial , Reproducibilidad de los Resultados , Fracturas del Cuello Femoral/cirugía , Toma de Decisiones Clínicas
3.
J Orthop Trauma ; 38(1): e9-e14, 2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-37735766

RESUMEN

OBJECTIVE: To compare rates of reduction loss, nonunion, and infection in intra-articular distal tibia fractures (IADTF) treated with limited open reduction internal fixation and intramedullary nailing (IMN) as compared to open reduction internal fixation with plate and screws (plate fixation [PF]). DESIGN: Retrospective review. SETTING: Level-I academic trauma center. PATIENT SELECTION CRITERIA: Patients age ≥ 18 with OTA/AO 43C1 and C2 IADTF treated with IMN or PF between 2013-2021. OUTCOME MEASURES AND COMPARISONS: Loss of reduction, surgical site infection (SSI), nonunion, and patient-reported outcomes (PROs) were compared for IMN versus PF treatments. RESULTS: One hundred ten patients met the inclusion criteria (IMN 33 and PF 77). There was no loss of reduction found. Seventeen nonunions (15% overall; IMN 4/33 and PF 13/77) and 13 SSIs (12% overall; IMN 2/33 and PF11/77) were identified. Despite several risk factors being identified for nonunion and SSI in bivariate analysis, only open fracture remained significant as a risk factor for both nonunion (odds ratio 0.09 for closed fracture, 95% confidence interval, 0.02-0.56, P = 0.009) and SSI (odds ratio 0.07 for closed fracture, 95% confidence interval, 0.06-0.26, P = 0.012) in the multivariate model. Propensity scoring based on presurgical variables was significantly different between patients who received IMN versus PF ( P = 0.03); however, logistic regression incorporating the propensity score revealed no significant association with nonunion and SSI. Adjusting for the propensity score, there remained no association comparing IMN versus PF with nonunion and SSI ( P = 0.54 and P = 0.17, respectively). There was also no difference in PROs between IMN and PF (physical function: P = 0.25 and pain interference: P = 0.21). CONCLUSIONS: Overall nonunion and SSI prevalence was 15% and 12%, respectively, in operatively treated OTA/AO 43C1 and C2 IADTF. An open fracture was a significant risk factor for nonunion and SSI. Metaphyseal fixation through IMN or PF did not affect loss of reduction, nonunion, SSI, or PROs. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.


Asunto(s)
Fracturas de Tobillo , Fijación Intramedular de Fracturas , Fracturas Cerradas , Fracturas Abiertas , Fracturas de la Tibia , Humanos , Fijación Intramedular de Fracturas/efectos adversos , Tibia/cirugía , Fracturas Abiertas/etiología , Puntaje de Propensión , Fracturas de la Tibia/cirugía , Fracturas de la Tibia/etiología , Estudios Retrospectivos , Análisis Multivariante , Infección de la Herida Quirúrgica/epidemiología , Infección de la Herida Quirúrgica/etiología , Fracturas de Tobillo/etiología , Resultado del Tratamiento
4.
J Orthop ; 50: 1-7, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38148925

RESUMEN

Background: Recent advancements in artificial intelligence (AI) have sparked interest in its integration into clinical medicine and education. This study evaluates the performance of three AI tools compared to human clinicians in addressing complex orthopaedic decisions in real-world clinical cases. Questions/purposes: To evaluate the ability of commonly used AI tools to formulate orthopaedic clinical decisions in comparison to human clinicians. Patients and methods: The study used OrthoBullets Cases, a publicly available clinical cases collaboration platform where surgeons from around the world choose treatment options based on peer-reviewed standardised treatment polls. The clinical cases cover various orthopaedic categories. Three AI tools, (ChatGPT 3.5, ChatGPT 4, and Bard), were evaluated. Uniform prompts were used to input case information including questions relating to the case, and the AI tools' responses were analysed for alignment with the most popular response, within 10%, and within 20% of the most popular human responses. Results: In total, 8 clinical categories comprising of 97 questions were analysed. ChatGPT 4 demonstrated the highest proportion of most popular responses (proportion of most popular response: ChatGPT 4 68.0%, ChatGPT 3.5 40.2%, Bard 45.4%, P value < 0.001), outperforming other AI tools. AI tools performed poorer in questions that were considered controversial (where disagreement occurred in human responses). Inter-tool agreement, as evaluated using Cohen's kappa coefficient, ranged from 0.201 (ChatGPT 4 vs. Bard) to 0.634 (ChatGPT 3.5 vs. Bard). However, AI tool responses varied widely, reflecting a need for consistency in real-world clinical applications. Conclusions: While AI tools demonstrated potential use in educational contexts, their integration into clinical decision-making requires caution due to inconsistent responses and deviations from peer consensus. Future research should focus on specialised clinical AI tool development to maximise utility in clinical decision-making. Level of evidence: IV.

5.
Orthop Clin North Am ; 52(2): 123-131, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33752833

RESUMEN

This article explores different nontraditional methods that could be adopted in clinical settings as alternatives to the traditional fibular fixation. Less invasive methods, such as intramedullary nail and screw fixation, might be viable alternatives for managing ankle fractures. These methods might especially benefit patients with poor soft tissue envelopes, low immunity, and poor bone quality. There is minimal soft tissue coverage for most orthopedic implants around the ankle. Various authors have highlighted the importance of minimally invasive surgery as an effective modality for ensuring superior prognosis for ankle fracture surgery or those fractures involving both the distal tibia and fibula.


Asunto(s)
Fracturas de Tobillo/cirugía , Peroné/lesiones , Peroné/cirugía , Fijación Interna de Fracturas/instrumentación , Fijadores Internos , Fijación Interna de Fracturas/métodos , Humanos
6.
JBJS Case Connect ; 10(1): e0467, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32044781

RESUMEN

CASE REPORT: A 65-year-old man presented with pain in his left ankle. After a delay, he presented to the orthopaedic clinic where computed tomography scan revealed an intra-articular, locked-lateral calcaneal fracture with dislocation of the peroneal tendons. CONCLUSIONS: This combination of injuries can produce subtle signs, such as an atypical double-density sign and varus talar tilt, on plain radiographs; however, the consequences of delayed treatment can be catastrophic. Early recognition and treatment are essential to avoid chronic pain and limited function.


Asunto(s)
Artrodesis/métodos , Calcáneo/lesiones , Traumatismos de los Pies/cirugía , Fracturas Óseas/cirugía , Anciano , Calcáneo/diagnóstico por imagen , Traumatismos de los Pies/diagnóstico por imagen , Fracturas Óseas/diagnóstico por imagen , Humanos , Masculino
7.
Injury ; 47(10): 2347-2351, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27381326

RESUMEN

INTRODUCTION: Spiral tibial shaft fractures are known to have a high rate of distal intra-articular extension; however, the risk of joint involvement caused by gunshots has not been thoroughly evaluated. The purpose of this study was to determine the incidence of intra- articular involvement in tibial shaft fractures caused by gunshots. The secondary purpose of this study was to assess the usefulness of ankle radiographs versus computed tomography (CT) scans in identifying these fractures. MATERIALS AND METHODS: Ninety consecutive patients were identified as having a tibia fracture caused by gunshot at a Level-1 trauma center. Forty-four of these patients were fractures of the mid to distal third shaft. Twenty-eight patients had ankle CT scans available for review, and 24 patients had dedicated ankle films. Three orthopaedic surgeons and a radiologist read the radiographs and CT scans. Sensitivity and specificity analysis was performed for the ankle radiographs using ankle CT scans as the gold standard. RESULTS: Seven of the twenty-eight fractures evaluated with a CT scan proved to have intra-articular involvement (Prevalence: 25%, 95% CI: 11.4%-45.2%). One of the seven intra-articular fractures was not seen on dedicated ankle radiographs (14.3%). The sensitivity of diagnosing an intra-articular extension on ankle radiographs was 0.85, 95%CI: 0.42-0.99. The specificity of diagnosing an intra-articular extension on ankle radiographs was 1.00, 95%CI: 0.81-1.00. Of the seven intra-articular fractures, three required additional treatment to address the intra-articular extension. CONCLUSION: The incidence of intra-articular involvement for tibial shaft fractures secondary to gunshot is less than that reported for spiral type fractures (11-45% vs. 25-58%). Although radiographs have a high specificity, the sensitivity is lower than expected, with worse outcomes if a fracture is missed. We recommend that a CT scan should be utilized to determine intra-articular extension in the setting of tibial shaft fractures caused by gunshots.


Asunto(s)
Fijación Interna de Fracturas , Fracturas Intraarticulares/cirugía , Radiografía , Fracturas de la Tibia/cirugía , Tomografía Computarizada por Rayos X , Heridas por Arma de Fuego/cirugía , Adolescente , Adulto , Fijación Interna de Fracturas/métodos , Curación de Fractura , Humanos , Incidencia , Fracturas Intraarticulares/diagnóstico por imagen , Fracturas Intraarticulares/fisiopatología , Persona de Mediana Edad , Estudios Retrospectivos , Fracturas de la Tibia/diagnóstico por imagen , Fracturas de la Tibia/fisiopatología , Estados Unidos , Heridas por Arma de Fuego/diagnóstico por imagen , Heridas por Arma de Fuego/fisiopatología , Adulto Joven
8.
Foot Ankle Spec ; 8(3): 220-5, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25156100

RESUMEN

UNLABELLED: Management of severely comminuted, complete articular tibial pilon fractures (AO/OTA 43-C) remains a challenge, with few treatment options providing good clinical outcomes. Open reduction and internal fixation of the tibial plafond, tibiotalar arthrodesis, and salvage hindfoot reconstruction procedures are all associated with surgical complications and functional limitations. In this report, we present a case of a complex pilon fracture in a patient with multiple medical comorbidities and socioeconomic disadvantages that was successfully and acutely treated with a retrograde tibiotalocalcaneal hindfoot arthrodesis nail. At final follow-up examination, the patient had decreased pain, a stable plantigrade foot, and could ambulate with normal shoes without any assistive devices. LEVELS OF EVIDENCE: Therapeutic, Level IV: Case series.


Asunto(s)
Traumatismos del Tobillo/cirugía , Artrodesis/métodos , Clavos Ortopédicos , Calcáneo/cirugía , Fijación Intramedular de Fracturas/instrumentación , Fracturas Conminutas/cirugía , Fracturas de la Tibia/cirugía , Traumatismos del Tobillo/diagnóstico por imagen , Calcáneo/diagnóstico por imagen , Femenino , Estudios de Seguimiento , Fracturas Conminutas/diagnóstico por imagen , Humanos , Persona de Mediana Edad , Diseño de Prótesis , Radiografía , Fracturas de la Tibia/diagnóstico por imagen , Factores de Tiempo
9.
Pol Orthop Traumatol ; 79: 97-101, 2014 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-25001924

RESUMEN

BACKGROUND: Radial head fractures are one of the more common fractures of the body, and the most common fractures around the elbow. CASE REPORT: While these can present in isolation, concomitant injuries to the ulna, elbow joint and surrounding ligaments, interosseous membrane, proximal radioulnar joint, and distal radioulnar joint can also occur. It is imperative that the treating surgeon rules out any concomitant injuries when evaluating a patient with a radial head fracture as the treatment options vary greatly depending on the structures which are damaged. CONCLUSIONS: Radial head resection, a viable treatment option for isolated radial head fractures, can lead to long-term sequelae if performed for a radial head fracture accompanied by interosseous membrane and distal radioulnar joint injury; this combination is termed an Essex-Lopresti injury. We will review the topic of Essex-Lopresti injuries, and discuss proper treatment options for these injuries.


Asunto(s)
Fracturas Conminutas/diagnóstico , Fracturas Conminutas/cirugía , Traumatismo Múltiple/diagnóstico , Traumatismo Múltiple/cirugía , Fracturas del Radio/diagnóstico , Fracturas del Radio/cirugía , Heridas por Arma de Fuego/cirugía , Codo/cirugía , Articulación del Codo/cirugía , Humanos , Masculino , Nervio Mediano/lesiones , Nervio Mediano/cirugía , Persona de Mediana Edad , Cúbito/lesiones , Cúbito/cirugía , Fracturas del Cúbito/diagnóstico , Fracturas del Cúbito/cirugía , Heridas por Arma de Fuego/diagnóstico , Lesiones de Codo
10.
Pol Orthop Traumatol ; 79: 5-9, 2014 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-24614610

RESUMEN

BACKGROUND: Galeazzi fractures are a rare injury to occur in adults, which are typically associated with high energy trauma. To our knowledge, the reported cases in the literature have only been associated with motor vehicle accidents, falls from a height, or athletic endeavors. The application of the force in the setting of a Galeazzi fracture has been disputed, but it is believed to occur with the wrist in hyperextension and pronation. CASE REPORT: We describe a 27-year-old male who presented with multiple gunshot wounds that included his right forearm. The injury sustained to his right forearm resulted in a Galeazzi fracture, which after open reduction and internal fixation, demonstrated subluxation of the distal radioulnar joint in pronation. CONCLUSIONS: We provide a novel mechanism of a Galeazzi fracture that demonstrates a method for sustaining the fracture pattern without the wrist in the typical position of hyperextension and pronation.


Asunto(s)
Traumatismo Múltiple/diagnóstico , Traumatismo Múltiple/terapia , Fracturas del Radio/diagnóstico , Fracturas del Radio/terapia , Heridas por Arma de Fuego/diagnóstico , Heridas por Arma de Fuego/terapia , Articulación Acromioclavicular/lesiones , Articulación Acromioclavicular/cirugía , Adulto , Traumatismos del Antebrazo/diagnóstico , Traumatismos del Antebrazo/terapia , Fijación Interna de Fracturas , Lesiones de la Cadera/diagnóstico , Lesiones de la Cadera/terapia , Humanos , Luxaciones Articulares/diagnóstico , Luxaciones Articulares/terapia , Traumatismos de la Rodilla/diagnóstico , Traumatismos de la Rodilla/terapia , Masculino , Examen Físico , Pronación , Fracturas del Radio/fisiopatología , Lesiones del Hombro , Muslo/lesiones
13.
Am J Emerg Med ; 31(7): 1151.e3-4, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23583117

RESUMEN

Calcaneal fractures account for 60% of all tarsal bone fractures. Tongue-type calcaneus fractures are longitudinal fractures that exit the calcaneal tuberosity posteriorly and involve a portion of the articular surface. They are often superiorly displaced because of the insertion of the Achilles tendon and pull of the gastroc-soleus complex. Skin compromise complicates a large percentage of these injuries because of the thin layer of soft tissue and superficial nature of the fracture. Early recognition by the emergency physician and prompt operative repair prevent further injury and obviate the need for surgical soft tissue coverage or potential amputation.


Asunto(s)
Calcáneo/lesiones , Fracturas Óseas/diagnóstico , Piel/patología , Fracturas Óseas/complicaciones , Humanos , Masculino , Necrosis/etiología , Adulto Joven
14.
Orthopedics ; 33(1): 53, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20055358

RESUMEN

This article describes 2 cases of spinal trauma in which diagnostic magnetic resonance imaging (MRI) was correlated with histopathology for diagnosis of a posterior ligamentous complex injury. Spine fractures are common and represent up to 16% of traumatic fractures. Diagnostic imaging currently involves plain films and computerized tomography, but MRI is being used with increasing frequency. The definition of neurologic tissue injury has had substantial documentation in the spinal literature. Clinically, posterior ligamentous complex injury has been associated with facet disruption, gapping of the spinous processes, and significant kyphosis. Assessment of spinal stability in the spine trauma population is based significantly on the assumed disruption or integrity of the posterior ligamentous complex. High signal intensity in the area of the ligamentum flavum and interspinous ligament on fat-saturated T2 MRIs has been associated with the clinical finding of interspinous ligament disruption noted at surgical exploration. Magnetic resonance imaging in spine trauma is widely accepted despite a paucity of data addressing its histopathologic accuracy. To our knowledge, histopathologic correlation of MRI of ligamentous injuries has not been reported.


Asunto(s)
Ligamentos Articulares/lesiones , Ligamentos Articulares/patología , Imagen por Resonancia Magnética/métodos , Traumatismos Vertebrales/patología , Vértebras Torácicas/lesiones , Vértebras Torácicas/patología , Adulto , Femenino , Humanos , Persona de Mediana Edad
15.
Cancer Invest ; 27(4): 435-42, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19212826

RESUMEN

There is no animal model that reflects the histological and radiographical heterogeneity of osteosarcoma. We assessed seven osteosarcoma cell lines for their potential to develop orthotopic tumors and lung metastasis in SCID mice. Whereas radiologically, 143B developed osteolytic tumors, SaOS-LM7 developed osteoblastic primary tumors. The mineralization status was confirmed by assessing the alkaline phosphatase activity and the microarray expression profile. We herein report a xenograft orthotopic osteosarcoma mouse model to assess osteoblastic and osteolytic lesions, which may contribute in the search for new diagnostic and therapeutic approaches.


Asunto(s)
Neoplasias Óseas/patología , Neoplasias Pulmonares/secundario , Osteoblastos/patología , Osteólisis/patología , Osteosarcoma/patología , Tibia/patología , Fosfatasa Alcalina/metabolismo , Animales , Densidad Ósea , Neoplasias Óseas/diagnóstico por imagen , Neoplasias Óseas/enzimología , Neoplasias Óseas/genética , Línea Celular Tumoral , Perfilación de la Expresión Génica/métodos , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Pulmonares/enzimología , Neoplasias Pulmonares/genética , Ratones , Ratones Endogámicos NOD , Ratones SCID , Análisis de Secuencia por Matrices de Oligonucleótidos , Osteoblastos/diagnóstico por imagen , Osteoblastos/enzimología , Osteólisis/diagnóstico por imagen , Osteólisis/enzimología , Osteólisis/genética , Osteosarcoma/diagnóstico por imagen , Osteosarcoma/enzimología , Osteosarcoma/genética , Radiografía , Tibia/diagnóstico por imagen , Tibia/enzimología , Factores de Tiempo , Ensayos Antitumor por Modelo de Xenoinjerto
16.
Biomaterials ; 29(14): 2193-202, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18262642

RESUMEN

This study describes investigation of porous photocrosslinked oligo[(polyethylene glycol) fumarate] (OPF) hydrogels as potential matrix for osteoblastic differentiation of marrow stromal cells (MSCs). The porosity and interconnectivity of porous hydrogels were assessed using magnetic resonance microscopy (MRM) as a noninvasive investigative tool that could image the water construct inside the hydrogels at a high-spatial resolution. MSCs were cultured onto the porous hydrogels and cell number was assessed using PicoGreen DNA assay. Our results showed 10% of cells initially attached to the surface of scaffolds. However, cells did not show significant proliferation over a time period of 14 days. MSCs cultured on porous hydrogels had increased alkaline phosphatase activity as well as deposition of calcium, suggesting successful differentiation and maturation to the osteoblastic phenotype. Moreover, continued expression of type I collagen and osteonectin over 14 days confirmed osteoblastic differentiation of MSCs. MRM was also applied to monitor osteogenesis of MSCs on porous hydrogels. MRM images showed porous scaffolds became consolidated with osteogenic progression of cell differentiation. These findings indicate that porous OPF scaffolds enhanced MSC differentiation leading to development of bone-like mineralized tissue.


Asunto(s)
Células de la Médula Ósea/citología , Hidrogeles/química , Células del Estroma/fisiología , Ingeniería de Tejidos/métodos , Fosfatasa Alcalina/análisis , Animales , Fenómenos Biomecánicos , Células de la Médula Ósea/fisiología , Calcificación Fisiológica/fisiología , Diferenciación Celular , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Materiales Biocompatibles Revestidos/química , Materiales Biocompatibles Revestidos/farmacología , Colágeno Tipo I/metabolismo , Reactivos de Enlaces Cruzados/química , Fumaratos/química , Masculino , Osteoblastos/citología , Osteoblastos/fisiología , Osteonectina/metabolismo , Fenotipo , Polietilenglicoles/química , Porosidad , Ratas , Ratas Sprague-Dawley , Espectroscopía Infrarroja por Transformada de Fourier , Células del Estroma/ultraestructura , Factores de Tiempo
17.
Orthopedics ; 31(12)2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19226051

RESUMEN

Reports of tiger attacks in the United States are rare. This article presents a case of a young woman who was violently attacked by a Siberian tiger and sustained penetrating trauma to the neck, cervical spine, and bilateral lower extremities. This article presents both diagnostic and therapeutic management of patients who may present with similar injuries. Animal bites from large animals are prone to infection in 10% to 20% of cases. Most infections are polymicrobial, with Pasteurella multicida being the most common isolate. Animal bites also mandate consideration of tetanus and rabies prophylaxis. The decision to administer postexposure rabies prophylaxis is dependent on the type of animal involved, whether the exposure was provoked, the local epidemiology of rabies, and the availability of the animal for observation or testing. Assessment of patients with cervical spine injury requires knowledge of possible associated injuries. Evaluation involves assessment of plain radiographs and computed tomography for evaluation of the cervical spine for bony injury. Furthermore, computed angiography is advantageous to noninvasively evaluate carotid or vertebral artery injury at the same setting in patients with deep cervical puncture wounds. Surgical treatment of unstable cervical spine fractures with lateral mass screw and rod fixation has been reported in the literature to have superior biomechanical properties compared to anterior and posterior instrumentation and fusion. In recent clinical studies, the use of lateral mass screws for traumatic injury of the cervical spine has been associated with excellent maintenance of alignment and minimal complications.


Asunto(s)
Mordeduras y Picaduras/complicaciones , Vértebras Cervicales/lesiones , Vértebras Cervicales/cirugía , Fracturas de la Columna Vertebral/etiología , Fracturas de la Columna Vertebral/cirugía , Heridas Penetrantes/etiología , Heridas Penetrantes/cirugía , Adulto , Animales , Mordeduras y Picaduras/cirugía , Femenino , Humanos , Traumatismo Múltiple/cirugía , Tigres , Resultado del Tratamiento
18.
Biomacromolecules ; 8(5): 1702-9, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17419584

RESUMEN

Photo-cross-linkable oligo[poly(ethylene glycol) fumarate] (OPF) hydrogels have been developed for use in tissue engineering applications. We demonstrated that compressive modulus of these hydrogels increased with increasing polymer concentration, and hydrogels with different mechanical properties were formed by altering the ratio of cross-linker/polymer in precursor solution. Conversely, swelling of hydrogels decreased with increasing polymer concentration and cross-linker/polymer ratio. These hydrogels are degradable and degradation rates vary with the change in cross-linking level. Chondrocyte attachment was quantified as a method for evaluating adhesion of cells to the hydrogels. These data revealed that cross-linking density affects cell behavior on the hydrogel surfaces. Cell attachment was greater on the samples with increased cross-linking density. Chondrocytes on these samples exhibited spread morphology with distinct actin stress fibers, whereas they maintained their rounded morphology on the samples with lower cross-linking density. Moreover, chondrocytes were photoencapsulated within various hydrogel networks. Our results revealed that cells encapsulated within 2-mm thick OPF hydrogel disks remained viable throughout the 3-week culture period, with no difference in viability across the thickness of hydrogels. Photoencapsulated chondrocytes expressed the mRNA of type II collagen and produced cartilaginous matrix within the hydrogel constructs after three weeks. These findings suggest that photo-cross-linkable OPF hydrogels may be useful for cartilage tissue engineering and cell delivery applications.


Asunto(s)
Cartílago/crecimiento & desarrollo , Condrocitos/citología , Hidrogeles/química , Poliésteres/efectos de la radiación , Polietilenglicoles/efectos de la radiación , Ingeniería de Tejidos , Animales , Cartílago/citología , Adhesión Celular , Línea Celular , Supervivencia Celular , Condrocitos/química , Condrocitos/metabolismo , Colágeno Tipo II/análisis , Colágeno Tipo II/genética , Colágeno Tipo II/metabolismo , Hidrogeles/síntesis química , Ratones , Fotoquímica , Poliésteres/síntesis química , Polietilenglicoles/síntesis química , ARN Mensajero/análisis , ARN Mensajero/metabolismo , Propiedades de Superficie , Rayos Ultravioleta
19.
J Bone Joint Surg Am ; 85(8): 1544-52, 2003 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12925636

RESUMEN

BACKGROUND: Bone morphogenic proteins (BMPs) are known to promote osteogenesis, and clinical trials are currently underway to evaluate the ability of certain BMPs to promote fracture-healing and spinal fusion. The optimal BMPs to be used in different clinical applications have not been elucidated, and a comprehensive evaluation of the relative osteogenic activity of different BMPs is lacking. METHODS: To identify the BMPs that may possess the most osteoinductive activity, we analyzed the osteogenic activity of BMPs in mesenchymal progenitor and osteoblastic cells. Recombinant adenoviruses expressing fourteen human BMPs (BMP-2 to BMP-15) were constructed to infect pluripotent mesenchymal progenitor C3H10T1/2 cells, preosteoblastic C2C12 cells, and osteoblastic TE-85 cells. Osteogenic activity was determined by measuring the induction of alkaline phosphatase, osteocalcin, and matrix mineralization upon BMP stimulation. RESULTS: BMP-2, 6, and 9 significantly induced alkaline phosphatase activity in pluripotential C3H10T1/2 cells, while BMP-2, 4, 6, 7, and 9 significantly induced alkaline phosphatase activity in preosteoblastic C2C12 cells. In TE-85 osteoblastic cells, most BMPs (except BMP-3 and 12) were able to induce alkaline phosphatase activity. The results of alkaline phosphatase histochemical staining assays were consistent with those of alkaline phosphatase colorimetric assays. Furthermore, BMP-2, 6, and 9 (as well as BMP-4 and, to a lesser extent, BMP-7) significantly induced osteocalcin expression in C3H10T1/2 cells. In C2C12 cells, osteocalcin expression was strongly induced by BMP-2, 4, 6, 7, and 9. Mineralized nodules were readily detected in C3H10T1/2 cells infected with BMP-2, 6, and 9 (and, to a lesser extent, those infected with BMP-4 and 7). CONCLUSIONS: A comprehensive analysis of the osteogenic activity of fourteen types of BMPs in osteoblastic progenitor cells was conducted. Our results suggest an osteogenic hierarchical model in which BMP-2, 6, and 9 may play an important role in inducing osteoblast differentiation of mesenchymal stem cells. In contrast, most BMPs are able to stimulate osteogenesis in mature osteoblasts.


Asunto(s)
Proteínas Morfogenéticas Óseas/farmacología , Mesodermo/citología , Osteoblastos/efectos de los fármacos , Osteocitos/efectos de los fármacos , Osteogénesis/efectos de los fármacos , Células Madre/efectos de los fármacos , Adenoviridae/genética , Fosfatasa Alcalina/metabolismo , Animales , Densidad Ósea/fisiología , Proteínas Morfogenéticas Óseas/clasificación , Proteínas Morfogenéticas Óseas/genética , Línea Celular , Técnicas de Transferencia de Gen , Humanos , Ratones , Osteosarcoma , Células Tumorales Cultivadas
20.
Cancer Lett ; 193(2): 161-70, 2003 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-12706873

RESUMEN

Beta-Catenin is a critical transducer of the Wnt signal pathway and plays an important role in many developmental and cellular processes. Deregulation of beta-catenin signaling has been observed in a broad range of human tumors. In this report, we investigated whether tyrosine kinase inhibitor STI-571 could inhibit the beta-catenin signaling activity and hence suppress cell proliferation. Our results demonstrated that STI-571 effectively inhibited the constitutive activity of beta-catenin signaling in human colon cancer cells as well as the Wnt1-induced activation of beta-catenin signaling in HOS, HTB-94, and HEK 293 cells. Furthermore, STI-571 was shown to effectively suppress the proliferation of human colon cancer cells. Finally, we demonstrated that the Wnt1-mediated activation of a GAL4-beta-catenin heterologous transcription system was effectively inhibited by STI-571. Thus, our findings suggest that tyrosine phosphorylation may play an important role in regulating beta-catenin signaling activity, and inhibition of this signaling pathway by STI-571 may be further explored as an important target for alternative/adjuvant treatments for a broader range of human cancer.


Asunto(s)
Antineoplásicos/farmacología , Proteínas del Citoesqueleto/biosíntesis , Regulación hacia Abajo , Inhibidores Enzimáticos/farmacología , Piperazinas/farmacología , Pirimidinas/farmacología , Transducción de Señal , Transactivadores/biosíntesis , Proteínas de Pez Cebra , Adenoviridae/genética , Benzamidas , División Celular , Línea Celular , Neoplasias del Colon/tratamiento farmacológico , Medios de Cultivo Condicionados/farmacología , Proteínas del Citoesqueleto/metabolismo , Relación Dosis-Respuesta a Droga , Genes Reporteros , Vectores Genéticos , Humanos , Mesilato de Imatinib , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas/biosíntesis , Factores de Tiempo , Transactivadores/metabolismo , Transcripción Genética , Activación Transcripcional , Células Tumorales Cultivadas , Proteínas Wnt , Proteína Wnt1 , beta Catenina
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