RESUMEN
OBJECTIVES: Only few studies evaluated hematogenous prosthetic joint infections. We aimed to describe the characteristics of these infections and factors associated with management failure. METHODS: We selected hematogenously-acquired infections, defined by the occurrence of infectious symptoms more than a year after implantation among records of patients treated for hip and knee prosthetic joint infections at Montpellier University Hospital between January 2004 and May 2015. Failure was defined by death due to prosthesis-related infection, need for prosthesis removal in case of conservative treatment, or recurrence of infectious signs on a new prosthesis. RESULTS: Forty-seven patients with hematogenous prosthetic joint infection were included (33 knee infections and 14 hip infections). Infectious agents were streptococci (43%), Staphylococcus aureus (43%), Gram-negative bacilli (13%), and Listeria monocytogenes (2%). Thirty-one patients were initially treated with debridement and implant retention and 15 with prosthesis removal (three with one-stage surgery, 10 with two-stage surgery). The median duration of antibiotic therapy was 66.5 days. The overall failure rate was 52% (24/48), 71% (22/31) with implant retention strategy, 13% (2/15) with prosthesis removal, and 63% (12/19) in case of Staphylococcus aureus infection. Conservative treatment was appropriate (arthrotomy on a well-implanted prosthesis without sinus tract and symptom onset <21 days) in 13/31 patients (42%) with a failure rate still high at 69% (9/13). The only factor associated with failure was conservative surgical treatment. CONCLUSION: The high risk of failure of conservative treatment for hematogenous prosthetic joint infections should lead to considering prosthesis replacement as the optimal strategy, particularly with Staphylococcus aureus.
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Artritis Infecciosa , Prótesis de la Rodilla , Infecciones Relacionadas con Prótesis , Infecciones Estafilocócicas , Antibacterianos/uso terapéutico , Artritis Infecciosa/tratamiento farmacológico , Desbridamiento , Humanos , Prótesis de la Rodilla/efectos adversos , Infecciones Relacionadas con Prótesis/tratamiento farmacológico , Infecciones Relacionadas con Prótesis/epidemiología , Infecciones Relacionadas con Prótesis/etiología , Estudios Retrospectivos , Infecciones Estafilocócicas/tratamiento farmacológico , Infecciones Estafilocócicas/epidemiología , Insuficiencia del Tratamiento , Resultado del TratamientoRESUMEN
Interest in wildlife epidemiology has increased in recent years. The control of diseases is critical for the survival of natural populations of economically valuable species. The present study is the first investigation of the etiology and epidemiology of skin ulceration disease in the sea cucumber Holothuria arguinensis, a new target species for fisheries and aquaculture in Europe. Bacterial cultures and molecular techniques were used to characterize this disease in animals collected during a survey across Ría Formosa Natural Park coastal lagoon in southern Portugal. Vibrio gigantis and V. crassostreae, which were both originally identified as disease agents in cultured oysters, were the most commonly isolated species of bacteria. Given that both sampling areas from which symptomatic H. arguinensis were collected were close to open oyster aquaculture facilities, this raises the possibility of an opportunistic infection, perhaps secondary to a decreased immune response caused by biotic or abiotic factors. An increase in prevalence of skin ulceration disease during the warmer season suggests that solar radiation and desiccation due to air exposure during low tide could be a cause of abiotic stress in the lagoon. Distributions of abundance and sizes of H. arguinensis in affected areas showed highest morbidity rates in adults. High fishery pressures throughout the study period could also cause elevations in prevalence and incidence rate of this disease. Skin ulcerative disease is endemic in this coastal lagoon. Disease monitoring is thus essential for the development of a conservation program to ensure the sustainability of fisheries and protection of natural resources.
Asunto(s)
Holothuria , Pepinos de Mar , Animales , Acuicultura , Europa (Continente) , Explotaciones PesquerasRESUMEN
Tyrosinase is a multi-copper enzyme which is widely distributed in different organisms and plays an important role in the melanogenesis and enzymatic browning. Therefore, its inhibitors can be attractive in cosmetics and medicinal industries as depigmentation agents and also in food and agriculture industries as antibrowning compounds. For this purpose, many natural, semi-synthetic and synthetic inhibitors have been developed by different screening methods to date. This review has focused on the tyrosinase inhibitors discovered from all sources and biochemically characterised in the last four decades.
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Chalcona/farmacología , Cumarinas/farmacología , Inhibidores Enzimáticos/farmacología , Flavonoides/farmacología , Monofenol Monooxigenasa/antagonistas & inhibidores , Resveratrol/farmacología , Agaricales/enzimología , Animales , Chalcona/química , Cumarinas/química , Inhibidores Enzimáticos/química , Flavonoides/química , Humanos , Monofenol Monooxigenasa/metabolismo , Resveratrol/químicaRESUMEN
Total knee arthroplasty (TKA) results in a high degree of patient satisfaction, as it provides patients with considerable medium- and long-term benefits in terms of quality of life, pain relief and function. Nevertheless, the literature reports that up to 30% of patients are dissatisfied. This dissatisfaction is directly related to the patients' quality of life, which they deem insufficient. Their quality of life depends on many physical, behavioural, social and psychological factors that are not taken into account by functional outcome scores. After describing the principles of quality of life evaluation after TKA, we will assess the effects of patient-related factors, the surgical technique and postoperative program through an exhaustive review of the literature. Patient expectations after TKA will then be outlined, particularly return to work and return to sports.
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Artroplastia de Reemplazo de Rodilla , Satisfacción del Paciente , Calidad de Vida , Artroplastia de Reemplazo de Rodilla/efectos adversos , Artroplastia de Reemplazo de Rodilla/métodos , Artroplastia de Reemplazo de Rodilla/psicología , Artroplastia de Reemplazo de Rodilla/rehabilitación , Humanos , Osteoartritis de la Rodilla/cirugía , Medición de Resultados Informados por el Paciente , Periodo Posoperatorio , Volver al Deporte , Reinserción al TrabajoRESUMEN
A revision stem may be required after a femoral extended trochanteric osteotomy (ETO) is made during revision hip arthroplasty. The two main complications of straight cementless femoral stems are subsidence due to inadequate osteointegration and stress-shielding. We will describe an original revision method with ETO that uses a straight cementless stem. The goal of this method was to achieve the most extensive press-fit possible during stem implantation to improve the transmission of stresses to the bone and to prevent reduction in bone density. The intramedullary preparation was done after closure and fixation of the ETO, which allows impaction of the revision stem with metaphyseal and diaphyseal press-fit. We report encouraging results with preservation of periprosthetic bone stock and good osteointegration of these revision stems at the final follow-up. Pronounced sagittal curvature or large bone defects are contraindications for this technique.
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Fémur/cirugía , Prótesis de Cadera , Anciano , Anciano de 80 o más Años , Artroplastia de Reemplazo de Cadera/métodos , Cementos para Huesos , Densidad Ósea , Femenino , Humanos , Masculino , Osteotomía/métodos , Proyectos Piloto , Diseño de Prótesis , Falla de Prótesis , Reoperación/métodos , Resultado del TratamientoRESUMEN
INTRODUCTION: Although using distally based sural flaps is old and common, the described harvesting methods vary and often depend on unclear vascular anatomical data. We wanted, through a review of the existing harvesting techniques and our clinical experience, to synthesize these aspects in order to provide an optimal, safe and customized use of distally based sural flaps. PATIENTS AND METHODS: Fifty-eight sural flaps were performed in 53.4-year-old patients in average, presenting in 81% of the cases one or more vascular comorbidities. The mean cover surface was of 30cm2. The flaps were mainly fasciocutaneous. The tunneling of the pedicle was performed in 34.5% of the cases. A skin blade was preserved above the pedicle in 37.9% of flaps. The short saphenous vein was anastomosed in 27.6% of the cases at the recipient site and ligatured distally in 19% of the cases. The mean follow-up was 18.9months. RESULTS: In 31% of cases, the skin paddle presented an obvious venous congestion during flap inset successfully treated with an anastomosis or a distal ligature of the short saphenous vein. We noticed in six other flaps (10.3%) a postoperative venous congestion having led to a skin paddle partial necrosis, of which five (8.6%) were treated without compromising the quality of the reconstruction. One patient required a coverage using another flap. CONCLUSION: When the microsurgery is not required or possible, the distally based sural flaps represent a safe level of the reconstructive armamentarium. Managing the pedicle's dissection and the venous drainage needs to be discussed case-by-case and adapted to peroperatory observations. The anastomosis or ligation of the small saphenous vein, as the existence of a thin skin blade under the skin paddle appear to increase vascular reliability of these flaps.
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Extremidad Inferior/cirugía , Colgajo Perforante/irrigación sanguínea , Traumatismos de los Tejidos Blandos/cirugía , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Disección/métodos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Procedimientos de Cirugía Plástica/métodos , Estudios Retrospectivos , Vena Safena/trasplante , Resultado del TratamientoRESUMEN
BACKGROUND: Developing criteria for assessing patellofemoral kinematics is crucial to understand, evaluate, and monitor patellofemoral function. The objective of this study was to assess a sequential 3D analysis method based on biplanar radiographs, using an in vitro protocol. HYPOTHESIS: Biplanar radiography combined with novel 3D reconstruction methods provides a reliable evaluation of patellofemoral function, without previous imaging. MATERIAL AND METHODS: Eight cadaver specimens were studied during knee flexion cycles from 0° to 60° induced by an in vitro simulator. The protocol was validated by investigating sequential and continuous motion using an optoelectronic system, evaluating measurement accuracy and reproducibility using metallic beads embedded in the patella, and comparing the 3D patellar geometry to computed tomography (CT) images. RESULTS: The differences in position between the sequential and continuous kinematic analyses were less than 1mm and 1°. The protocol proved reliable for tracking several components of knee movements, including patellar translations, flexion, and tilt. In this analysis, uncertainty was less than 2 mm for translations and less than 3° for rotations, except rotation in the coronal plane. For patellar tilt, uncertainty was 5°. Mean difference in geometry was 0.49 mm. DISCUSSION: Sequential analysis results are consistent with continuous kinematics. This analysis method provides patellar position parameters without requiring previous CT or magnetic resonance imaging. A clinical study may deserve consideration to identify patellofemoral kinematic profiles and position criteria in vivo. LEVEL OF EVIDENCE: IV, experimental study.
Asunto(s)
Imagenología Tridimensional , Articulación Patelofemoral/diagnóstico por imagen , Articulación Patelofemoral/fisiología , Anciano , Fenómenos Biomecánicos/fisiología , Cadáver , Femenino , Humanos , Masculino , Radiografía , Reproducibilidad de los ResultadosRESUMEN
INTRODUCTION: The influence of radiographic bone density changes in the area surrounding a total hip arthroplasty (THA) revision with a cementless press-fit stem is unknown, notably in terms of functional results. We have therefore conducted a study aiming to (1) propose a radiographic method to assess bone density, (2) measure the functional effects of reduced bone density, and (3) determine the factors contributing to these modifications. HYPOTHESIS: A reduction in radiographic bone density has a negative influence on the functional result after revision using a cementless press-fit stem. MATERIAL AND METHODS: We retrospectively assessed 150 THA revisions at a mean follow-up of 6.3 ± 3.2 years (range, 2-15 years). The clinical assessment was based on the Harris Hip Score. Bone density modifications were measured radiographically and the method was evaluated. The change in bone density was classified into two groups: (1) bone density not reduced or < 2 Gruen zones (118 cases [79%]); (2) bone density reduced ≥ 2 zones (32 cases [21%]). The variables showing a potential influence were the Cortical Index (CI), the type of primary stability with the press-fit system, and the femoral implant length. RESULTS: Inter- and intraobserver reliability of radiographic bone density measurement was evaluated as moderate or good (Kappa, 0.58; 0.60 and 0.67, respectively). For the Harris Hip Score at follow-up, there was a borderline statistical relation between stages 1 and 2: for the 118 stage 1 patients, this score was 83.62 ± 11.54 (range, 27-99) versus 78.34 ± 15.98 (range, 62-91) for stage 2 patients (P = 0.09). A CI ≤ 0.44 showed mediocre bone quality contributing to decreased bone density (P < 0.02). On the other hand, there was no statistically significant relation with the type of primary fixation (P = 0.34) or the length of the implant (P = 0.23). CONCLUSIONS: A cementless revision femoral stem can induce a reduction in bone density with possible functional effects. The negative role played by bone scarcity on the functional score is confirmed, and even though the difference is not statistically significant, we suggest using a short stem when this is possible.
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Artroplastia de Reemplazo de Cadera/efectos adversos , Densidad Ósea , Fémur/diagnóstico por imagen , Prótesis de Cadera/efectos adversos , Cadera/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Falla de Prótesis , Radiografía , Reoperación/instrumentación , Reproducibilidad de los Resultados , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
INTRODUCTION: Brain growth plays likely an important role for the skull growth. In the fetus, there exists an heterochrony for the growth of supratentorial (forebrain) and infratentorial regions (brainstem and cerebellum). The aim of the study was thus to model geometrically the growth of these two regions and to compare it with the inflection of the base of skull. MATERIAL AND METHODS: Brain growth measurements were performed from midsagittal photographs of fetal brains obtained from an Anatomical Atlas over a period from 10 to 40 amenorrhea weeks (AW). After countouring and pointing anatomical and geometrical landmarks, we have developed a linear growth model based on principal component analysis (PCA). Besides, the variation of the sphenoidal and clivo-foraminal angles was studied from anatomical midsagittal slices of fetal heads sampled over a period from 16 to 39 AW. RESULTS: The PCA model brings to light the radial expansion of the forebrain growth (first component) associated with an inferior and posterior rotation of the occipital lobe. The growth of the infratentoriel region presents an inferior and posterior expansion associated with a second component corresponding to inferior and anterior expansions. From the 17 AW, appears an heterochrony between the supra- and infratentorial growths and an inversion of the ratio between the infra- and supratentorial dimensions after 30 AW. The sphenoidal and clivo-foraminal angles decrease slightly until 25 AW, and then increase quickly until the 39 AW. CONCLUSIONS: The growth of brain is accompanied by morphological change between the compartments supra- and infratentoriel but also on the level of the base of skull. The possible interactions will be discussed.
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Encéfalo/embriología , Atlas como Asunto , Tronco Encefálico/embriología , Cefalometría , Cerebelo/embriología , Edad Gestacional , Humanos , Modelos Neurológicos , Prosencéfalo/embriología , Base del Cráneo/embriologíaRESUMEN
INTRODUCTION: Lateral release of the sesamoid ligament complex is one of the key step to the surgical treatment of hallux valgus. Although numerous techniques are available to perform this procedure, there is no accepted consensus on the method of choice. The goal of this study was to evaluate the efficacy of sequential release of lateral soft tissue structures for correction of hallux valgus deformity. PATIENTS AND METHODS: This study included 40 patients, mean age 50.9 years old (±17.4), with 49 hallux valgus deformities from mechanical causes. The first metatarsophalangeal angle (M1P1), the intermetatarsal angle (M1M2) and the position of the sesamoids in relation to mechanical axis of M (according to the Research Committee of the American Orthopedic Foot and Ankle Society) were determined on preoperative X-rays. During the procedure, lateral release was performed in several steps: sectioning the metatarsosesamoid suspensory ligament then sectioning the phalangeal insertional band (PIB) and complete detachment of the adductor on the fibular sesamoid ligament. We measured the changes in the M1P1 and M1M2 angles during this step-by-step release. RESULTS: The M1P1 angle decreased during each step of release and went from 29.9° to 11.1° (P<0.001). The M1M2 decreased by 1.70° following medial capusolorrhaphy. Simple capsulorrhaphy reduced the hallux valgus deformity by 8.2° (44%). Release of the metatarsosesamoid suspensory ligament resulted in a decrease of 3.9° (or 21% of total release), release of the PIB in a decrease of 5.1° (27%) and complete detachment of the adductor in a decrease of 1.5° (8%). Thirty six percent of the sesamoids were reduced after metatarsosesamoid ligament resection, 56% after PIB release, and 60% after adductor release. DISCUSSION: Lateral soft tissue release is ensured in most cases by sectioning the metatarsosesamoid suspensory ligament and the PIB. Release of the adductor from the fibular sesamoid has a limited effect. CONCLUSION: Lateral soft tissue release should include sectioning the metatarsosesamoid suspensory ligament and detaching the PIB. This release should be enough to correct the deformity without performing any osteotomy in hallux valgus with M1P1<27° and M1M2<10°, as long as a stable medial plane can be obtained. LEVEL OF EVIDENCE: Level IV.
Asunto(s)
Hallux Valgus/cirugía , Ligamentos Articulares/cirugía , Articulación Metatarsofalángica/cirugía , Procedimientos Ortopédicos/métodos , Adulto , Anciano , Femenino , Estudios de Seguimiento , Hallux Valgus/diagnóstico por imagen , Hallux Valgus/fisiopatología , Humanos , Masculino , Articulación Metatarsofalángica/diagnóstico por imagen , Persona de Mediana Edad , Estudios Prospectivos , Radiografía , Rango del Movimiento Articular , Resultado del Tratamiento , Adulto JovenRESUMEN
INTRODUCTION: In rheumatoid diseases, hindfoot arthrodesis abolishes pain and corrects deformity. The choice between selective and double arthrodesis depends on whether the hindfoot malalignment is fixed or not. Indications for surgery are well codified. The various types of arthrodesis have never been assessed together on a large series. We here report a series that is substantial in numbers and in follow-up. MATERIALS AND METHODS: A continuous single-center retrospective study included patients with native hindfoot inflammatory disease treated by arthrodesis between 1996 and 2009. RESULTS: Around 80% of patients were followed up, for a mean 7 years. Fifty-four isolated talonavicular arthrodeses, 14 talocalcaneal arthrodeses and 39 double arthrodeses were performed. 96% of patients had rheumatoid arthritis and 4% spondylarthritis. 62% were completely pain-free at follow-up. The satisfaction rate was 91% and mean AOFAS score 70%. 6% of patients showed symptomatic non-union, mainly associated with talonavicular arthrodesis. In 22% of double arthrodeses and 11% of talonavicular arthrodeses, ankle status required surgical revision. In double arthrodesis, there was no correlation between hindfoot deviation and secondary deterioration in ankle status. Talocalcaneal arthrodesis was associated with radiologic hindfoot varus, both preoperatively and at follow-up. DISCUSSION: Non-union was the main complication in talonavicular arthrodesis. The rate of secondary ankle surgery was significantly elevated in double arthrodesis. These findings support Suckel's cadaver studies, which, in 2007, reported early deterioration in ankle status in double arthrodesis, due to mechanical overloading. Talocalcaneal arthrodesis proved reliable and simple, free of major complications and with a 100% satisfaction rate. CONCLUSION: Double arthrodesis showed the greatest benefit in terms of restoring foot architecture, but was associated with a higher rate of deterioration in ankle status. Preventive double arthrodesis is not recommended in case of isolated arthritis with reducible hindfoot malalignment.
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Artritis Reumatoide/complicaciones , Artrodesis/métodos , Desviación Ósea/cirugía , Deformidades Adquiridas del Pie/cirugía , Rango del Movimiento Articular/fisiología , Articulación Talocalcánea/cirugía , Adulto , Anciano , Artritis Reumatoide/diagnóstico , Artrodesis/efectos adversos , Desviación Ósea/etiología , Estudios de Cohortes , Femenino , Deformidades Adquiridas del Pie/diagnóstico por imagen , Deformidades Adquiridas del Pie/etiología , Humanos , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Complicaciones Posoperatorias/diagnóstico por imagen , Complicaciones Posoperatorias/cirugía , Pronóstico , Radiografía , Recuperación de la Función , Reoperación , Estudios Retrospectivos , Medición de Riesgo , Índice de Severidad de la Enfermedad , Articulación Talocalcánea/diagnóstico por imagen , Articulaciones Tarsianas/diagnóstico por imagen , Articulaciones Tarsianas/cirugía , Resultado del TratamientoRESUMEN
An acetylcholine-selective electrode based on a plasticized polymeric membrane has been developed. The electrode exhibited good selectivity for acetylcholine (ACh) over choline and some common ions, low drift, and a fast response to ACh. The response was linear over an ACh concentration range of 1×10(-6) to 1×10(-3) M with a slope of 59.1±0.1 and a detection limit of 1.5×10(-7)±1.2×10(-8) M. The electrode was used to monitor enzymatic ACh hydrolysis catalyzed by acetylcholinesterase (AChE) at different substrate and enzyme concentrations. A kinetic data analysis permitted the determination of the Michaelis-Menten constant of the enzymatic hydrolysis and AChE activity in the range of 2×10(-5) to 3.8×10(-1)U ml(-1).
Asunto(s)
Acetilcolina/análisis , Acetilcolinesterasa/análisis , Técnicas Biosensibles/métodos , Potenciometría/métodos , Hidrólisis , CinéticaRESUMEN
INTRODUCTION: Secondary subsidence of a revision femoral stem is often a negative predictive sign for successful osseointegration and perfect long-term stability. MATERIALS AND METHODS: We performed a retrospective study in a series of 183 revision total hip replacements between 1996 and 2000 to evaluate the importance and risk factors of secondary subsidence with a cementless press-fit design femoral stem as well as this subsidence's consequences to osseointegration. RESULTS: Secondary subsidence did not occur in 80 cases (53%), was between 0 and 4mm in 41 cases (27%); between 5 and 10mm in 17 cases (12%) and was greater than 10mm in 12 cases (8%). Mean subsidence of all patients was 3mm (0-30). There was a statistically significant negative correlation between subsidence and the quality of osseointegration (P=0.03). There was no significant relationship between component diameter and stem subsidence (P=0.9). The presence of preoperative bone deficiencies did not increase the risk of secondary subsidence (P=0.2). CONCLUSION: In the case of revision with press-fit stems, the importance of secondary subsidence should not be overestimated, because it usually does not negatively affect satisfactory osseointegration.
Asunto(s)
Artroplastia de Reemplazo de Cadera , Prótesis de Cadera , Adulto , Anciano , Anciano de 80 o más Años , Análisis de Varianza , Distribución de Chi-Cuadrado , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Oseointegración , Complicaciones Posoperatorias/cirugía , Diseño de Prótesis , Falla de Prótesis , Reoperación , Estudios Retrospectivos , Factores de Riesgo , Resultado del TratamientoRESUMEN
In higher plants, ammonium is assimilated into amino acids through the glutamine synthetase (GS)/glutamate synthase (GOGAT) cycle. This metabolic cycle is distributed in different cellular compartments in conifer seedlings: glutamine synthesis occurs in the cytosol and glutamate synthesis within the chloroplast. A method for preparing intact chloroplasts of pine cotyledons is presented with the aim of identifying a glutamine-glutamate translocator. Glutamine-glutamate exchange has been studied using the double silicone layer system, suggesting the existence of a translocator that imports glutamine into the chloroplast and exports glutamate to the cytoplasm. The translocator identified is specific for glutamine and glutamate, and the kinetic constants for both substrates indicate that it is unsaturated at intracellular concentrations. Thus, the experimental evidence obtained supports the model of the GS/GOGAT cycle in developing pine seedlings that accounts for the stoichiometric balance of metabolites. As a result, the efficient assimilation of free ammonia produced by photorespiration, nitrate reduction, storage protein mobilisation, phenylpropanoid pathway or S-adenosylmethionine synthesis is guaranteed.
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Cloroplastos/enzimología , Glutamato Sintasa/metabolismo , Glutamato-Amoníaco Ligasa/metabolismo , Glutamina/metabolismo , Pinus/enzimología , Amoníaco/metabolismo , Fraccionamiento Celular/métodos , Cotiledón/enzimología , Ácido Glutámico/metabolismo , Proteínas de Plantas/metabolismoRESUMEN
Under aerobic or anaerobic conditions, tyrosinase undergoes a process of irreversible inactivation induced by its physiological substrate L-dopa. Under aerobic conditions, this inactivation occurs through a process of suicide inactivation involving the form oxy-tyrosinase. Under anaerobic conditions, both the met- and deoxy-tyrosinase forms undergo irreversible inactivation. Suicide inactivation in aerobic conditions is slower than the irreversible inactivation under anaerobic conditions. The enzyme has less affinity for the isomer D-dopa than for L-dopa but the velocity of inactivation is the same. We propose mechanisms to explain these processes.
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Dihidroxifenilalanina/química , Monofenol Monooxigenasa/química , Agaricales/enzimología , Catálisis , Dominio Catalítico , Catecol Oxidasa/química , Cinética , Espectroscopía de Resonancia Magnética , Modelos Biológicos , Modelos Químicos , Oxígeno/química , Unión Proteica , Espectrofotometría/métodos , Factores de TiempoRESUMEN
Characterizing osteochondral lesions of the talus has enabled the strategies of surgical management to be better specified. The main technical problem is one of access for arthroscopy instruments to posteromedial lesions. A range of techniques and approaches has been described in ankle arthroscopy in general, and a transmalleolar approach provides reliable and efficient access in these cases. It is frequently used for transchondral drilling, but also enables satisfactory implant positioning in autologous osteochondral mosaicplasty procedures. We report our technique and results on five cases with a minimum 1.2 years' follow-up.
Asunto(s)
Traumatismos del Tobillo/cirugía , Artrografía , Artroscopía/métodos , Trasplante Óseo/métodos , Cartílago Articular/lesiones , Cartílago/trasplante , Imagenología Tridimensional , Fracturas Intraarticulares/cirugía , Imagen por Resonancia Magnética , Osteocondritis/cirugía , Cirugía Asistida por Computador/métodos , Astrágalo/cirugía , Adulto , Cartílago Articular/cirugía , Estudios de Factibilidad , Femenino , Estudios de Seguimiento , Humanos , Fracturas Intraarticulares/diagnóstico , Masculino , Persona de Mediana Edad , Osteocondritis/diagnóstico , Complicaciones Posoperatorias/diagnóstico , Recolección de Tejidos y Órganos/métodos , Adulto JovenRESUMEN
There is controversy in the literature concerning the action of tetrahydropterines on the enzyme tyrosinase and on melanogenesis in general. In this study, we demonstrate that tetrahydropterines can inhibit melanogenesis in several ways: i) by non-enzymatic inhibition involving purely chemical reactions reducing o-dopaquinone to L-dopa, ii) by acting as substrates which compete with L-tyr and L-dopa, since they are substrates of tyrosinase; and iii) by irreversibly inhibiting the enzymatic forms met-tyrosinase and deoxy-tyrosinase in anaerobic conditions. Three tetrahydropterines have been kinetically characterised as tyrosinase substrates: 6-R-L-erythro-5,6,7,8-tetrahydrobiopterin, 6-methyl-5,6,7,8-tetrahydropterine and 6,7-(R,S)-dimethyl-5,6,7,8-tetrahydropterine. A kinetic reaction mechanism is proposed to explain the oxidation of these compounds by tyrosinase.
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Melaninas/biosíntesis , Monofenol Monooxigenasa/antagonistas & inhibidores , Pterinas/farmacología , Agaricales/enzimología , Unión Competitiva , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Cinética , Levodopa/metabolismo , Monofenol Monooxigenasa/metabolismo , Oxidación-Reducción , Pterinas/química , Especificidad por Sustrato , Tirosina/metabolismoRESUMEN
The management of high-energy trauma to the foot often requires multiple tissues reconstructive procedures with various technical options. The authors report the case of a patient presenting an extensive defect of the medioplantar region of the right foot involving an almost complete (90%) medial cuneiform bone loss. A deferred operation with saphenous cross-leg flap and interposition of a cement spacer was first performed. Reconstruction of the bone defect with corticocancellous iliac bone graft was subsequently carried out at two months post-trauma. At four months follow-up, the bone and soft tissues healing were good. At 24 months follow-up, the patient could return to normal professional and sports activities. The saphenous cross-leg flap has proven to be a reliable reconstructive procedure. The use of the modified Masquelet technique ensured an anatomical reconstruction and a satisfying final functional outcome.
Asunto(s)
Traumatismos de los Pies/cirugía , Procedimientos de Cirugía Plástica/métodos , Colgajos Quirúrgicos/irrigación sanguínea , Accidentes de Tránsito , Traumatismos de los Pies/diagnóstico por imagen , Humanos , Masculino , Radiografía , Recuperación de la Función , Vena Safena/trasplante , Adulto JovenRESUMEN
PURPOSE OF THE STUDY: Sesamoid bones of the hallux play a major role in the biomechanics of the metatarsophalangeal complex. Due to the deformations resulting from hallux valgus, the sesamoid system is exposed to abnormal stress forces. Mapping the degenerative cartilage shows the significant prevalence of these lesions and their relation with the anatomic deformation. The purpose of this work was to determine the impact of these metatarsosesamoidal joint changes on the results of Scarf procedure for hallux valgus. MATERIAL AND METHODS: This series included 89 patients (100 feet) who underwent Scarf osteotomy with complementary phalangeal osteotomy. We distinguished two groups in this cohort: 78 cases of surgery not involving the lateral metatarsals (group A), and 22 cases with associated lateral metatarsal osteotomy (group B). Mean follow-up was 2.3 years; minimal follow-up 16 months. The study protocol was prospective, with preoperative and last follow-up radiological and clinical assessment by an independent operator. Joint lesions noted intraoperatively by one senior operator were noted. The clinical work-up included the AOFAS score. A 15 degrees anteroposterior weight-bearing view was used to determine the degree of sesamoid dislocation and measure the following angles: first metatarsophalangeal angle (M1P1), first intermetatarsal space (M1M2), proximal articular set angle (PASA). Eleven zones were described to map the joint surfaces. The statistical analysis was used to search for links between joint lesions and the radiographic and clinical findings. RESULTS: The joint cartilage analysis revealed lesions involving the sesamoid bones in 72 cases, with a preferential involvement of the medial sesamoid bone (67%). The plantar joint surface of the first metatarsal presented lesions in the medial gutter in 72 cases, and in the lateral gutter in 68. Complete absence of the intersesamoid crest was noted in 38%. The metatarsophalangeal compartment presented degenerative lesions in 15 cases. The preoperative assessment noted a positive significant correlation between the AOFAS overall score and the absence of lesions involving the lateral sesamoid bone (p=0.015), between the AOFAS pain score and the absence of lesions involving the lateral sesamoid bone (p=0.022), between the AOFAS pain score and the complete absence of the intersesamoid crest (p=0.001), between the AOFAS deviation score and the absence of lesion involving the lateral gutter (p=0.001), between the M1P1 angle and the absence of an intersesamoid crest (p=0.001). At last follow-up, there was a positive significant correlation between the absence of lesions involving the medial sesamoid bone and a better overall AOFAS score (p=0.014), between absence of a lateral sesamoid lesion and better postoperative sentering of the sesamoids (p=0.014), between the absence of lesion in the medial gutter and a higher postoperative M1P1 angle (p=0.002), between the absence of lesions involving the lateral gutter and more favorable overall AOFAS score (p=0.005) for function (p=0.022), and deviation (p=0.018), between the absence of intersesamoid crest lesions and better radiographic sesamoid recentering (p=0.020). Distinct analysis of groups A and B did not demonstrate a significant difference compared with the overall cohort. Comparison of the two groups only demonstrated three significant differences involving radioclinical parameters. DISCUSSION: Hallux valgus is associated with very frequent metatarsosesamoid lesions. The distribution of these lesions is a function of the anatomic and biomechanical features of the metatarsosesamoid joint surfaces. Lesions to the lateral compartment would be a poor prognostic factor for Scarf procedure.
Asunto(s)
Enfermedades de los Cartílagos/complicaciones , Enfermedades de los Cartílagos/cirugía , Cartílago Articular , Articulaciones del Pie , Hallux Valgus/complicaciones , Hallux Valgus/cirugía , Huesos Metatarsianos , Huesos Sesamoideos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios ProspectivosRESUMEN
OBJECTIVE: To understand the mechanism by which (-)-epigallocatechin-3-gallate (EGCG), the major polyphenol of green tea, exerts its anti-inflammatory action. METHODS: To check our hypothesis that the anti-inflammatory properties of EGCG could be related to its antifolate action and whether adenosine and its receptors are involved in EGCG action, we investigated the EGCG-induced suppression of NF-kappaB in Caco-2 cell monolayer, which acted as a model of the human intestinal epithelium. RESULTS: We demonstrate that the anti-inflammatory properties of EGCG are associated with its antifolate activity. By using a natural stable folate we were able to reverse the EGCG suppression of TNF-alpha-induced NF-kappaB activation, the phosphorylation and degradation of IkappaBalpha and the phosphorylation of Akt in this human colon carcinoma cell line. These suppressions were mediated by the release of adenosine following disruption of the folate cycle by EGCG. By binding to its specific receptors, adenosine can modulate the Akt and NF-kappaB pathway. Moreover, EGCG produces a significant increase in a specific adenosine receptor, which could explain the suppression of the constitutive activation of NF-kappaB in colon cancer cells. CONCLUSIONS: The data suggest that by modulating NF-kappaB activation, EGCG might not only combat inflammation, but also cancer.