Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 36
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
J Pediatr Orthop ; 2024 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-38853742

RESUMEN

OBJECTIVE: Tibial tubercle avulsion fractures (TTAFs) represent 0.4% to 2.7% of pediatric physeal injuries. These injuries are thought to confer a risk of acute compartment syndrome (ACS), and these patients are often admitted for compartment monitoring and, in many cases, undergo prophylactic fasciotomy. This study sought to review our institution's experience with TTAF and associated compartment syndrome in pediatric patients. METHODS: All patients aged 8 to 18 years with TTAF at our institution from January 1, 2017 to January 1, 2023 were retrospectively reviewed. Patient demographics, injury mechanism, fracture morphology, and postinjury course were reviewed. ACS was diagnosed by clinical exam or necessitating therapeutic compartment fasciotomy. RESULTS: A total of 49 TTAFs in 47 patients were included in the final analysis. The mean age was 14.5 ± 1.2 years (range: 11 to 17), and males were significantly older than females (14.6 ± 1.1 vs 13.3 ± 1.3 y, P = 0.01). The average body mass index was 27.1 ± 7.0, and males had a significantly lower body mass index than females (26.3 ± 6.5 vs 34.1 ± 8.5, P = 0.03). Basketball was the most common mechanism of injury (49%), followed by soccer (13%), football (11%), trampoline (6%), fall (6%), jumping (4%), lacrosse (4%), running (4%), and softball (2%). The Ogden fracture types were as follows: I: 10%; II: 16%; III: 41%; IV: 24%; V: 8%. Thirty-four patients (69%) were admitted to the hospital for at least one night after presentation. Forty-six (96%) underwent surgical fixation an average of 3.5 days after injury. No patients developed ACS during their post-injury or postoperative course. Three patients underwent the removal of hardware. No other complications were observed. The average follow-up duration was 238 days. CONCLUSIONS: The results of this study suggest that the risk of ACS in pediatric patients with TTAF may be small enough to allow for same-day discharge after diagnosis or operative management in patients deemed to be sufficiently low risk by clinical judgment. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

2.
J Pediatr Orthop ; 44(1): e91-e96, 2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-37820256

RESUMEN

INTRODUCTION: Amid a national opioid epidemic, it is essential to review the necessity of opioid prescriptions. Research in adults has demonstrated patients often do not use their entire postoperative opioid prescription. Limited data suggest that the trend is similar in children. This study investigated the prescription volume and postoperative utilization rate of opioids among pediatric orthopaedic surgery patients at our institution. METHODS: We identified pediatric patients (ages below 18 y old) who presented to our institution for operating room intervention from May 24, 2021, to December 13, 2021. Patient demographics and opioid prescription volume were recorded. Parents and guardians were surveyed by paper "opioid diary" or phone interview between postoperative days 10 to 15, assessing pain level, opioid use, and plans for remaining opioid doses. Wilcoxon rank-sum test, Independent t test, and Pearson correlation were used for the analysis of continuous variables. Multivariable logistic regression was used to control for patient demographic variables while analyzing opioid usage relationships. RESULTS: Prescription volume information was collected for 280 patients during the study period. We were able to collect utilization information for 102 patients (Group 1), whereas the remaining 178 patients contributed only prescription volume data (Group 2). Patients with upper extremity fractures received significantly fewer opioid doses at discharge compared with other procedure types ( P =0.036). Higher BMI was positively correlated with more prescribed opioid doses ( R2 =0.647, P <0.001). The mean opioid utilization rate was 22.37%. A total of 50.6% of patients prescribed opioids at discharge used zero doses. A total of 96.2% of patients used opioids for 5 days or less. Most families had not disposed of excess medication by postoperative day 10. CONCLUSIONS: We found significant differences in opioid prescribing practices based on patient and procedure-specific variables. In addition, although our pediatric orthopaedic surgery patients had low overall rates of postoperative opioid utilization, there was significant variation in opioid use among procedure types. These results provide insights that can guide opioid prescribing practices for pediatric orthopaedic patients and promote patient education to ensure safe opioid disposal.


Asunto(s)
Trastornos Relacionados con Opioides , Procedimientos Ortopédicos , Ortopedia , Adulto , Niño , Humanos , Analgésicos Opioides/uso terapéutico , Prescripciones de Medicamentos , Dolor Postoperatorio/tratamiento farmacológico , Pautas de la Práctica en Medicina
3.
Wirtschaftsdienst ; 100(9): 712-717, 2020.
Artículo en Alemán | MEDLINE | ID: mdl-33082606

RESUMEN

After the launch of Bitcoin in 2008 and the subsequent introduction of more than 6,600 cryptocurrencies, a new wave of innovative payment projects is currently on its way, including innovations like Libra - designed as a supranational stable coin - and central bank digital currencies (CBDCs). Various interrelations link these private and public projects. Contrary to the original intentions, Bitcoin has not developed into a widespread means of payments, not the least due to its considerable price volatility. Its most significant contribution could be the "proof of concept" for an innovative, private means of payment outside the conventional monetary system. In contrast, Libra is designed as a rather conventional means of payment with close relations with the existing banking sector, which raises numerous policy questions concerning monetary and financial stability. Central bank digital currencies could be viewed as a public sector response to these private projects to secure central banks' predominant role in the monetary system of the future.

4.
Pediatr Emerg Care ; 33(5): 329-333, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-26414633

RESUMEN

OBJECTIVES: The aim of the study was to describe the long leg cast with a pelvic band (LLCPB), a novel alternative to spica casting for treating femur fractures in patients aged 6 months to 6 years which requires no casting above the waist, allows for hip flexion adjustments after it is applied, and does not require an operating room for placement. METHODS: Seven children aged 7.9 months to 3.7 years with femur fractures treated with the LLCPB at a single institution were retrospectively studied. All children were casted in the emergency department under conscious sedation. Radiographic and subjective outcomes were recorded. RESULTS: All 7 children achieved acceptable reduction of their fractures without the need for re-reduction or cast wedging. Five of the 7 children were discharged from the emergency department; 1 child required 1 night of hospitalization and another child required 2 nights of hospitalization. There were no complications. The cost of placing an LLCPB at our institution was $430.46. The cost of placing a spica cast in the operating room was $5427.54 to $6465.00. CONCLUSIONS: The long leg cast with a pelvic band seems to be an acceptable treatment for children aged 8 months to 4 years with spiral femur fractures. This technique has significant advantages over traditional and modified spica casts including allowing for uninhibited toileting, weight bearing on the unaffected leg, adjustment of hip flexion at any point after placement, and easier access to the perineum, abdomen, and chest for hygienic and medical purposes. Furthermore, treatment with an LLCPB presents significant potential for cost savings.


Asunto(s)
Moldes Quirúrgicos/normas , Fracturas del Fémur/diagnóstico por imagen , Pelvis/fisiología , Férulas (Fijadores)/normas , Moldes Quirúrgicos/economía , Preescolar , Servicio de Urgencia en Hospital , Femenino , Fracturas del Fémur/economía , Fracturas del Fémur/epidemiología , Fracturas del Fémur/terapia , Hospitalización/estadística & datos numéricos , Humanos , Lactante , Masculino , Estudios Retrospectivos , Férulas (Fijadores)/economía , Resultado del Tratamiento , Soporte de Peso/fisiología , Rayos X
5.
J Pediatr Orthop ; 34(4): 382-7, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24248589

RESUMEN

BACKGROUND: Because of the changing referral patterns, operative pediatric supracondylar humerus fractures are increasingly being treated at tertiary referral centers. To expedite patient flow, type II fractures are sometimes pinned in a delayed manner. We sought to determine if delay in surgical treatment of modified Gartland type II supracondylar humerus fractures would affect the rate of complications following closed reduction and percutaneous pinning. METHODS: We performed a retrospective review of a consecutive series of 399 modified Gartland type II supracondylar fractures treated operatively at a tertiary referral center over 4 years. Mean patient age in the type II group was 5 years (range, 1 to 15 y). A total of 48% were pinned within 24 hours, 52% pinned >24 hours after the injury. RESULTS: No difference was in detected in rates of major complications between the early and delayed treatment group. Four percent of patients sustained a complication (16 patients). There were no compartment syndromes, vascular injuries, or permanent nerve injuries. Complications included nerve injury (3), physical therapy referral for stiffness (3), pin site infection (2 treated with oral antibiotics, 4 treated with debridement), refracture (2), and loss of fixation or broken hardware (2). Of the 3 patients who sustained nerve injuries, all underwent surgery within 24 hours of injury. One patient developed an ulnar motor and sensory nerve palsy after fixation with crossed K-wires. This resolved by 7 weeks postoperatively. Two patients presented with an anterior interosseous nerve palsy-1 resolved 1 week after surgery, the other by 8 weeks postoperatively. CONCLUSIONS: Delay in surgery did not result in an increased rate of major complications following closed reduction and percutaneous pinning of type II supracondylar humerus fractures in children. Further prospective work is necessary to determine if there are subtle treatment benefits from emergent treatment of type II supracondylar humerus fractures. LEVEL OF EVIDENCE: Level III-retrospective comparative series.


Asunto(s)
Fracturas del Húmero/cirugía , Complicaciones Posoperatorias/clasificación , Complicaciones Posoperatorias/epidemiología , Periodo Preoperatorio , Centros de Atención Terciaria/estadística & datos numéricos , Adolescente , Clavos Ortopédicos , Hilos Ortopédicos , Niño , Preescolar , Síndromes Compartimentales/epidemiología , Desbridamiento , Femenino , Estudios de Seguimiento , Fijación Intramedular de Fracturas , Humanos , Húmero/cirugía , Lactante , Masculino , Traumatismos de los Nervios Periféricos/epidemiología , Modalidades de Fisioterapia , Falla de Prótesis , Recurrencia , Reoperación/estadística & datos numéricos , Estudios Retrospectivos , Infección de la Herida Quirúrgica/epidemiología , Factores de Tiempo , Resultado del Tratamiento
6.
J Pediatr Orthop ; 34(1): 34-9, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23812149

RESUMEN

BACKGROUND: The safety of delayed surgical treatment of severe supracondylar elbow fractures in children remains debated. No large studies have evaluated complications of injury and surgery evaluating only type 3 fractures. Our aim was to review the results of our experience treating children with severe supracondylar elbow fractures at various time points after injury. METHODS: All children treated operatively for supracondylar humerus fractures from 2004 to 2007 at a single pediatric trauma center were identified. A total of 1296 children had operative treatment, of which 872 had type 3 fractures. Clinical records were reviewed to identify time to surgery from presentation at our institution. Patients were grouped into 4 cohorts [<6 h (n=325), 6 to 12 h (n=224), 12 to 24 h (n=295), and >24 h (n=28)]. Emergency, operative, inpatient, and outpatient records were reviewed to determine morbidity at presentation as well as operative and postoperative complications. RESULTS: There was no difference in sex, age, or energy mechanism between children in the various time groups. An absent pulse was found in 54 children (6%) at presentation, of which only 5 ultimately required a vascular intervention. Nerve injury occurred in 105 patients (12%). Use of a medial entry pin was not associated with ulnar nerve injury. Increased time from presentation to surgery was not associated with increased morbidity from the injury or treatment complications. In contrast, there was a trend to steady decrease in morbidity and complication rates with increased time to surgery. CONCLUSIONS: This is the largest single-center study of severe supracondylar humerus fractures and describes rates of vascular compromise, nerve injury, infection, and other complications of these injuries. Most children with type 3 supracondylar humerus fractures can be treated safely in a delayed manner. Appropriate clinical judgment is imperative to optimize outcomes. LEVEL OF EVIDENCE: Level III--retrospective comparative study.


Asunto(s)
Lesiones de Codo , Fijación Interna de Fracturas/métodos , Fracturas del Húmero/diagnóstico por imagen , Fracturas del Húmero/cirugía , Fracturas Intraarticulares/cirugía , Rango del Movimiento Articular/fisiología , Adolescente , Niño , Preescolar , Estudios de Cohortes , Diagnóstico Tardío , Articulación del Codo/cirugía , Femenino , Estudios de Seguimiento , Fijación Interna de Fracturas/efectos adversos , Humanos , Incidencia , Puntaje de Gravedad del Traumatismo , Fracturas Intraarticulares/diagnóstico por imagen , Masculino , Análisis Multivariante , Traumatismos de los Nervios Periféricos/etiología , Traumatismos de los Nervios Periféricos/fisiopatología , Complicaciones Posoperatorias/diagnóstico por imagen , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/terapia , Radiografía , Recuperación de la Función , Estudios Retrospectivos , Medición de Riesgo , Infección de la Herida Quirúrgica/epidemiología , Infección de la Herida Quirúrgica/fisiopatología , Factores de Tiempo , Resultado del Tratamiento , Nervio Cubital/lesiones
7.
Acta Crystallogr D Struct Biol ; 80(Pt 3): 159-173, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38372588

RESUMEN

Complex I (proton-pumping NADH:ubiquinone oxidoreductase) is the first component of the mitochondrial respiratory chain. In recent years, high-resolution cryo-EM studies of complex I from various species have greatly enhanced the understanding of the structure and function of this important membrane-protein complex. Less well studied is the structural basis of complex I biogenesis. The assembly of this complex of more than 40 subunits, encoded by nuclear or mitochondrial DNA, is an intricate process that requires at least 20 different assembly factors in humans. These are proteins that are transiently associated with building blocks of the complex and are involved in the assembly process, but are not part of mature complex I. Although the assembly pathways have been studied extensively, there is limited information on the structure and molecular function of the assembly factors. Here, the insights that have been gained into the assembly process using cryo-EM are reviewed.


Asunto(s)
Complejo I de Transporte de Electrón , Mitocondrias , Humanos , Complejo I de Transporte de Electrón/química , Complejo I de Transporte de Electrón/genética , Complejo I de Transporte de Electrón/metabolismo , Microscopía por Crioelectrón , Mitocondrias/metabolismo
8.
Redox Biol ; 72: 103142, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38581860

RESUMEN

Platelets are the critical target for preventing and treating pathological thrombus formation. However, despite current antiplatelet therapy, cardiovascular mortality remains high, and cardiovascular events continue in prescribed patients. In this study, first results were obtained with ortho-carbonyl hydroquinones as antiplatelet agents; we found that linking triphenylphosphonium cation to a bicyclic ortho-carbonyl hydroquinone moiety by a short alkyl chain significantly improved their antiplatelet effect by affecting the mitochondrial functioning. The mechanism of action involves uncoupling OXPHOS, which leads to an increase in mitochondrial ROS production and a decrease in the mitochondrial membrane potential and OCR. This alteration disrupts the energy production by mitochondrial function necessary for the platelet activation process. These effects are responsive to the complete structure of the compounds and not to isolated parts of the compounds tested. The results obtained in this research can be used as the basis for developing new antiplatelet agents that target mitochondria.


Asunto(s)
Plaquetas , Hidroquinonas , Potencial de la Membrana Mitocondrial , Mitocondrias , Compuestos Organofosforados , Inhibidores de Agregación Plaquetaria , Especies Reactivas de Oxígeno , Mitocondrias/metabolismo , Mitocondrias/efectos de los fármacos , Humanos , Inhibidores de Agregación Plaquetaria/farmacología , Inhibidores de Agregación Plaquetaria/química , Hidroquinonas/farmacología , Hidroquinonas/química , Plaquetas/metabolismo , Plaquetas/efectos de los fármacos , Compuestos Organofosforados/farmacología , Compuestos Organofosforados/química , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Agregación Plaquetaria/efectos de los fármacos , Activación Plaquetaria/efectos de los fármacos , Fosforilación Oxidativa/efectos de los fármacos
9.
J Orthop ; 46: 174-177, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38031628

RESUMEN

Purpose: The goal of this study was to define the outcomes of patients following hip arthroscopy and to identify potential factors, found during hip arthroscopy, that were associated with patients' eventual conversion to total hip arthroplasty (THA). Methods: Patients who had undergone hip arthroscopy from January 2010 to January 2015 were retrospectively reviewed and patients were reported if they had a THA in the same hip. Patients were followed up to December 2022 resulting in between 7 and 12 years of follow-up. Measures from the hip scope including joint space width and cartilage grades were reported. Differences in these measures and demographics were compared between patients who had THA after hip arthroscopy and those who did not with T-tests. Results: Patients who had hip arthroscopy and were then converted to THA were significantly older than those patients who did not have THA (50.3 vs 42.0 years) (p = 0.039). The average time of conversion to THA from index hip arthroscopy was 3.59 years with a range of 0.48-8.91 years. Joint space width in patients converted to THA was significantly less, 3.08 mm ± 1.93 mm, compared to non-THA converted patients, 3.62 mm ± 0.88 mm (p < 0.001). Conclusions: Older age and smaller joint space width of the hip was associated with patients who were converted to THA following hip arthroscopy. Level of evidence: Level III.

10.
J Am Acad Orthop Surg ; 20(11): 715-24, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23118137

RESUMEN

Benign tumors in the spine include osteoid osteoma, osteoblastoma, aneurysmal bone cyst, osteochondroma, neurofibroma, giant cell tumor of bone, eosinophilic granuloma, and hemangioma. Although some are incidental findings, some cause local pain, radicular symptoms, neurologic compromise, spinal instability, and deformity. The evaluation of spinal tumors includes a thorough history and physical examination, imaging, sometimes laboratory evaluation, and biopsy when indicated. Appropriate treatment may be observational (eg, eosinophilic granuloma) or ablative (eg, osteoid osteoma, neurofibroma, hemangioma), but generally is surgical, depending on the level of pain, instability, neurologic compromise, and natural history of the lesion. Knowledge of the epidemiology, common presentation, imaging, and treatment of benign bone tumors is essential for successful management of these lesions.


Asunto(s)
Neoplasias Óseas/diagnóstico , Neoplasias Óseas/terapia , Enfermedades de la Columna Vertebral/diagnóstico , Enfermedades de la Columna Vertebral/terapia , Quistes Óseos Aneurismáticos/diagnóstico , Quistes Óseos Aneurismáticos/terapia , Neoplasias Óseas/patología , Granuloma Eosinófilo/diagnóstico , Granuloma Eosinófilo/terapia , Tumor Óseo de Células Gigantes/diagnóstico , Tumor Óseo de Células Gigantes/terapia , Hemangioma/diagnóstico , Hemangioma/terapia , Humanos , Neurofibroma/diagnóstico , Neurofibroma/terapia , Osteoblastoma/diagnóstico , Osteoblastoma/terapia , Osteocondroma/diagnóstico , Osteocondroma/terapia , Osteoma Osteoide/diagnóstico , Osteoma Osteoide/terapia , Pronóstico , Enfermedades de la Columna Vertebral/patología , Resultado del Tratamiento
11.
Arthroscopy ; 28(10): 1533-9, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22607830

RESUMEN

PURPOSE: To perform a biomechanical analysis of suture bridge fixation for tibial eminence fractures using PushLock anchors (Arthrex, Naples, FL) and compare it with traditional suture fixation and screw fixation. METHODS: This study used 24 porcine knees, divided into 3 comparison fixation groups: PushLock suture bridge fixation, screw fixation, and suture fixation. Each knee was dissected of all soft tissue, leaving only the anterior cruciate ligament. A tibial eminence fracture was created with disruption of the posterior hinge, and each knee was fixed with a randomly assigned fixation technique. After fixation, each knee underwent 2 phases of biomechanical testing. The initial cyclic dynamic phase assessed the displacement change after 200 cycles (in millimeters) and initial stiffness (in Newtons per millimeter) of the fixation construct. After completion of dynamic testing, each specimen underwent a single tensile failure test load to assess ultimate failure load (in Newtons) and displacement (in millimeters) to ultimate failure. RESULTS: There was a significant difference for the load-to-failure outcome variable among treatment groups (P = .004 by analysis of variance, 1 - ß = 0.851). Mean ultimate failure load borne by the PushLock fixation group was statistically significantly higher in comparison with the screw (P = .007) and suture (P = .017) fixation groups. For the cyclical testing, the primary outcome variable of displacement change after 200 loading cycles failed to show a significant difference among the 3 groups (P = .412). CONCLUSIONS: Suture bridge fixation with PushLock anchors is a new and effective surgical technique for the treatment of displaced tibial eminence fractures. By use of a high-bone density animal model, our results suggest that this suture bridge construct provides superior fixation with regard to ultimate failure load compared with standard screw fixation and suture fixation. CLINICAL RELEVANCE: The suture bridge technique provides another fixation option for displaced tibial eminence fractures with comparable, and in some instances superior, biomechanical properties to screw fixation and suture fixation.


Asunto(s)
Articulación de la Rodilla/cirugía , Técnicas de Sutura/instrumentación , Fracturas de la Tibia/cirugía , Animales , Fenómenos Biomecánicos , Tornillos Óseos , Modelos Animales de Enfermedad , Articulación de la Rodilla/fisiopatología , Anclas para Sutura , Porcinos , Resistencia a la Tracción , Fracturas de la Tibia/fisiopatología
12.
J Pediatr Orthop ; 32(6): 567-72, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22892617

RESUMEN

BACKGROUND: Supracondylar humerus fractures are the most common operative fractures in children; however, no studies describe the older child with this injury. The purpose of this study was to compare Gartland type III supracondylar humerus fractures in children older than 8 years of age with those in younger children than age 8. We hypothesized that there would be more complications in older children, reflecting a higher-energy injury mechanism. METHODS: A retrospective chart review of supracondylar humerus fractures managed at a single level I pediatric trauma institution from 2004 to 2007 was performed. Patients with type III fractures were divided into groups based on age at presentation greater or less than 8. Baseline demographics, fracture characteristics, mechanism of injury, operative technique, and complications were analyzed. RESULTS: A consecutive series of 1297 pediatric patients with surgically treated supracondylar humerus fractures was retrospectively reviewed including 873 (67.3%) type III fractures. Of those, 160 (18.3%) patients were older than age 8 at time of injury. Older children were more likely to have fractures from high-energy mechanisms (45.1% vs. 28.7%, P<0.001) and more open fracture (3.8% vs. 1.3%, P=0.0097). There was no difference in preoperative or iatrogenic neuropraxias between groups. There was a shorter delay between presentation and surgery in older children (mean, 217 vs. 451 min, P<0.0001). Three or more pins were used more often in older patients (61.8% in older children vs. 43.6% in younger children, P<0.0001). Major complications including reoperation, loss of fixation, or compartment syndrome were rare in both groups (1.1% in younger group vs. 0.6% in older group, P=1.000). There was a trend toward more pin site infections in older children (3.75% vs. 1.56%, P=0.071). Physical therapy was required nearly 4 times more frequently in older children for management of residual stiffness (20.0% vs. 5.7%, P<0.0001). CONCLUSIONS: Children older than 8 years of age have a higher rate of open supracondylar humerus fractures, although nerve injury rates are similar. Surgeons placed more pins for fixation of fractures in older patients and elbow stiffness requiring physical therapy occurred more commonly after surgical intervention. EVIDENCE: III Retrospective cohort.


Asunto(s)
Clavos Ortopédicos , Fijación de Fractura/métodos , Fracturas del Húmero/patología , Modalidades de Fisioterapia , Factores de Edad , Niño , Femenino , Fijación de Fractura/instrumentación , Humanos , Fracturas del Húmero/complicaciones , Fracturas del Húmero/cirugía , Masculino , Reoperación/estadística & datos numéricos , Estudios Retrospectivos , Infección de la Herida Quirúrgica/epidemiología , Factores de Tiempo , Índices de Gravedad del Trauma
13.
Pharmaceuticals (Basel) ; 15(9)2022 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-36145309

RESUMEN

NADH:ubiquinone oxidoreductase (respiratory complex I) is a redox-driven proton pump with a central role in mitochondrial oxidative phosphorylation. The ubiquinone reduction site of complex I is located in the matrix arm of this large protein complex and connected to the membrane via a tunnel. A variety of chemically diverse compounds are known to inhibit ubiquinone reduction by complex I. Rotenone, piericidin A, and annonaceous acetogenins are representatives of complex I inhibitors from biological sources. The structure of complex I is determined at high resolution, and inhibitor binding sites are described in detail. In this review, we summarize the state of knowledge of how natural inhibitors bind in the Q reduction site and the Q access pathway and how their inhibitory mechanisms compare with that of a synthetic anti-cancer agent.

14.
Sci Adv ; 8(46): eadd3855, 2022 Nov 18.
Artículo en Inglés | MEDLINE | ID: mdl-36383672

RESUMEN

Respiratory complex I is a ~1-MDa proton pump in mitochondria. Its structure has been revealed in great detail, but the structural basis of its assembly, in humans involving at least 15 assembly factors, is essentially unknown. We determined cryo-electron microscopy structures of assembly intermediates associated with assembly factor NDUFAF1 in a yeast model system. Subunits ND2 and NDUFC2 together with assembly factors NDUFAF1 and CIA84 form the nucleation point of the NDUFAF1-dependent assembly pathway. Unexpectedly, the cardiolipin remodeling enzyme tafazzin is an integral component of this core complex. In a later intermediate, all 12 subunits of the proximal proton pump module have assembled. NDUFAF1 locks the central ND3 subunit in an assembly-competent conformation, and major rearrangements of central subunits are required for complex I maturation.

15.
Front Chem ; 9: 672851, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33996767

RESUMEN

NADH: ubiquinone oxidoreductase (complex I) is the first enzyme complex of the respiratory chain. Complex I is a redox-driven proton pump that contributes to the proton motive force that drives ATP synthase. The structure of complex I has been analyzed by x-ray crystallography and electron cryo-microscopy and is now well-described. The ubiquinone (Q) reduction site of complex I is buried in the peripheral arm and a tunnel-like structure is thought to provide access for the hydrophobic substrate from the membrane. Several intermediate binding positions for Q in the tunnel were identified in molecular simulations. Structural data showed the binding of native Q molecules and short chain analogs and inhibitors in the access pathway and in the Q reduction site, respectively. We here review the current knowledge on the interaction of complex I with Q and discuss recent hypothetical models for the coupling mechanism.

16.
Clin Orthop Relat Res ; 468(3): 670-8, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19484317

RESUMEN

UNLABELLED: Skeletally immature patients with adolescent idiopathic scoliosis are at risk for curve progression. Although numerous nonoperative methods have been attempted, including physical therapy, exercise, massage, manipulation, and electrical stimulation, only bracing is effective in preventing curve progression and the subsequent need for surgery. Brace treatment is initiated as either full-time (TLSO, Boston) or nighttime (Charleston, Providence) wear, although patient compliance with either mode of bracing has been a documented problem. We review the natural history of adolescent idiopathic scoliosis, identify the risks for curve progression, describe the types of braces available for treatment, and review the indications for and efficacy of brace treatment. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.


Asunto(s)
Tirantes , Escoliosis/terapia , Adolescente , Bases de Datos Bibliográficas , Progresión de la Enfermedad , Diseño de Equipo , Femenino , Humanos , Masculino , Escoliosis/etiología , Escoliosis/fisiopatología , Resultado del Tratamiento
17.
Phys Sportsmed ; 38(3): 105-13, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20959703

RESUMEN

Success in sports is often defined by winning, which drives athletes to use performance-enhancing drugs (PEDs) to gain an advantage over opponents. Over the past 20 years, use of PEDs by Olympic and professional athletes has led to public discussion regarding potential negative health effects and ethical implications of their use. Unfortunately, PEDs are not isolated to professional athletes, as PED use in adolescents has increased dramatically. Many professional organizations, including the American Academy of Orthopaedic Surgeons (AAOS), have taken a stance against PED use in sports. The AAOS believes neither anabolic steroids nor their precursors should be used to enhance performance or appearance, and that these substances should be banned in all sports programs. Pediatricians and orthopedists are often the first physicians to see these young athletes. It is critical for these physicians to recognize the significance of the problem, have the knowledge to inform adolescents, dissuade them from future use, and provide viable alternatives for meeting performance goals.


Asunto(s)
Anabolizantes/administración & dosificación , Anabolizantes/efectos adversos , Rendimiento Atlético , Doping en los Deportes/prevención & control , Músculo Esquelético/efectos de los fármacos , Adolescente , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Masculino , Sociedades Médicas , Detección de Abuso de Sustancias/métodos
18.
J Hip Preserv Surg ; 7(2): 340-344, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33163220

RESUMEN

Several studies have demonstrated that patients have significant impairments in understanding their injury and appropriate course of management in orthopedic surgery. The purpose of this investigation is to determine if patients are able to obtain a fundamental understanding of the requisite care associated with hip arthroscopy. Any patient who elected to have hip arthroscopy was prospectively recruited to participate in the study. All patients were told they would be asked to complete a questionnaire about their surgery and post-operative instructions. The answers to each question of the questionnaire they would receive at the first post-operative visit were verbally given to each patient during the pre-operative visit. They were also given a post-operative instruction sheet on the day of surgery that contained answers to the questionnaire. At the first post-operative visit, all patients were then asked to complete a multiple-choice questionnaire prior to seeing the surgeon. A total of 56 patients (14 males, 42 females) were enrolled. All patients reported they had read the post-operative instruction sheet. The average number of correct answers was 6.5 ± 0.6 (95% CI 6 - 7) out of 11 questions (59% correct response rate ±18% [95% CI 52 - 66%]). Although we made significant pre-operative oral and written efforts to help patients achieve an elementary level of health literacy regarding their forthcoming hip arthroscopy, many patients did not achieve satisfactory comprehension. Even with instruction and information given verbally and physically (via post-operative instruction sheet) patients did not obtain satisfactory comprehension of their surgical procedure. New ways (through video, simplified cartoons or verbal explanations) must be considered in educating patients concerning surgical procedures to increase comprehension and health literacy.

19.
Foot Ankle Int ; 29(1): 34-41, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18275734

RESUMEN

BACKGROUND: Surgical specialties have become increasingly subspecialized. An expanding demand for foot and ankle care administered by trained specialists has driven the need for foot and ankle-trained orthopaedic surgeons. This survey was designed to elucidate the reasons why residents choose a career in foot and ankle surgery. METHODS: We conducted a national, anonymous, 11-question survey of past, present, and prospective foot and ankle fellows (156 mailed). The questions focused on trying to understand the decision-making process in pursuing a foot and ankle fellowship, and assessing the overall satisfaction of this career choice. Questionnaires were returned within one month of their mailing. RESULTS: We achieved a 40% overall response rate. The fellow's relationship with their residency program's foot and ankle specialist was the primary catalyst for pursuing foot and ankle as a career. Nearly all respondents were satisfied with their decision to do a foot and ankle fellowship, though some were disappointed early in practice with remuneration, practice competition, and patient dissatisfaction. American Orthopaedic Foot and Ankle Society (AOFAS) membership was nearly unanimous. CONCLUSION: The relationship established between a resident and his or her foot and ankle mentor while in training appears to have the greatest impact on pursuing foot and ankle surgery as a career. Once in practice, few trained fellows regret their decision, and few report disappointments not similarly voiced by other orthopaedic subspecialties. Based on this data, the importance of a foot and ankle rotation elective during orthopaedic residency and the impact subspecialty service attending have on resident interests and career choices seem clear.


Asunto(s)
Selección de Profesión , Becas , Ortopedia/educación , Tobillo/cirugía , Conducta de Elección , Pie/cirugía , Humanos , Satisfacción en el Trabajo , Mentores , Encuestas y Cuestionarios , Estados Unidos
20.
J Am Acad Orthop Surg ; 25(4): 251-259, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28291142

RESUMEN

Lower extremity avulsion fractures are uncommon in the pediatric population and can be misdiagnosed without proper imaging and/or clinical suspicion for these injuries. The most common locations of avulsion injuries are the ischial tuberosity, anterior superior iliac spine, and anterior inferior iliac spine. Less often, avulsion fractures occur in the tibial tubercle, calcaneus, and greater and lesser trochanters. When treated properly with rest and altered weight bearing, most of these injuries heal without complication. Although surgical intervention is rarely necessary, it has a high degree of success when it is used. However, avulsion injuries are often misdiagnosed as muscle strains or apophysitis and are mistakenly treated with early range of motion. An error in diagnosis and/or management can cause nonunion or further displacement, which may require surgery. Improper identification of these injuries can also lead to nerve irritation, chronic pain, and gait dysfunction. Awareness of these injuries and their natural history is important because healed avulsion fractures may resemble neoplastic bone on radiographs.


Asunto(s)
Traumatismos en Atletas/diagnóstico , Errores Diagnósticos/efectos adversos , Fracturas por Avulsión/diagnóstico , Extremidad Inferior/lesiones , Adolescente , Traumatismos en Atletas/terapia , Niño , Diagnóstico Diferencial , Femenino , Fracturas por Avulsión/terapia , Humanos , Masculino
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA