RESUMEN
AIMS: The aim of this study was to evaluate the effects of using a portable, accelerometer-based surgical navigation system (KneeAlign2) in total knee arthroplasty (TKA) on the alignment of the femoral component, and blood loss. PATIENTS AND METHODS: A total of 241 consecutive patients with primary osteoarthritis of the knee were enrolled in this prospective, randomised controlled study. There were 207 women and 34 men. The mean age of the patients was 74.0 years (57 to 89). The KneeAlign2 system was used for distal femoral resection in 121 patients (KA2 group) and a conventional intramedullary femoral guide was used in 120 patients (IM group). RESULTS: One patient (0.8%) in the KA2 group and 19 in the IM group had an alignment which was > 3° away from the neutral mechanical axis (p < 0.01). The mean deviation from neutral alignment was 1.01° (standard deviation (sd) 1.0°) in the KA2 group and 1.93° (sd 1.7°) in the IM group (p < 0.01). Blood loss was significantly less in the KA2 group compared with the IM group (784 ml (sd 357) versus 1071 ml (sd 310), p < 0.001). CONCLUSION: The KneeAlign2 system provides a technically straightforward method for identifying the femoral head and performing an accurate distal femoral resection at TKA with significantly less blood loss compared with a conventional intramedullary guide. Cite this article: Bone Joint J 2017;99-B:1047-52.
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Acelerometría/instrumentación , Artroplastia de Reemplazo de Rodilla/métodos , Prótesis de la Rodilla , Osteoartritis de la Rodilla/cirugía , Cirugía Asistida por Computador/métodos , Anciano , Anciano de 80 o más Años , Diseño de Equipo , Femenino , Estudios de Seguimiento , Humanos , Articulación de la Rodilla/diagnóstico por imagen , Articulación de la Rodilla/cirugía , Masculino , Persona de Mediana Edad , Osteoartritis de la Rodilla/diagnóstico , Estudios Prospectivos , Radiografía , Resultado del TratamientoRESUMEN
BACKGROUND AND OBJECTIVE: Tissue engineering by using recombinant human (rh) growth factor technology may offer a promising therapeutic approach for treatment of gingival recession. Fibroblast growth factor-2 (FGF-2) has shown the ability to promote periodontal regeneration. Gelatin/beta-tricalcium phosphate (gelatin/ß-TCP) sponges have been developed to control the release of growth factors. The present study evaluated the periodontal regenerative efficacy of rhFGF-2 by comparing gelatin/ß-TCP sponges incorporated with rhFGF-2 to the scaffolds alone in artificially created recession-type defects in dogs. MATERIAL AND METHODS: Critically sized buccal gingival recession defects were surgically created on maxillary canine teeth of five dogs. In each animal, defects were randomized to receive either a gelatin/ß-TCP sponge soaked with rhFGF-2 (gelatin/ß-TCP/rhFGF-2) or phosphate-buffered saline (gelatin/ß-TCP). Eight weeks after surgery, biopsy specimens were obtained and subjected to microcomputed tomography and histological analyses. RESULTS: Complete root coverage was achieved in both groups. Microcomputed tomography revealed significantly greater new bone volume in the gelatin/ß-TCP/rhFGF-2 group. Histologically, both groups achieved periodontal regeneration; however, gelatin/ß-TCP/rhFGF-2 sites exhibited more tissue regeneration, characterized by significantly larger amounts of new cementum and new bone. Gelatin/ß-TCP sites featured increased long junctional epithelium and connective tissue attachment. In the gelatin/ß-TCP/rhFGF-2 sites, new bone exhibited many haversian canals and circumferential lamellae as well as remarkably thick periosteum with blood vascularization and hypercellularity. CONCLUSION: Within the limitations of this study, rhFGF-2 in gelatin/ß-TCP sponges exhibits an increased potential to support periodontal wound healing/regeneration in canine recession-type defects.
Asunto(s)
Fosfatos de Calcio/uso terapéutico , Factor 2 de Crecimiento de Fibroblastos/uso terapéutico , Gelatina/uso terapéutico , Recesión Gingival/cirugía , Recesión Gingival/terapia , Proteínas Recombinantes/uso terapéutico , Ingeniería de Tejidos/métodos , Animales , Vasos Sanguíneos/diagnóstico por imagen , Vasos Sanguíneos/patología , Regeneración Ósea , Tejido Conectivo/patología , Diente Canino/diagnóstico por imagen , Diente Canino/patología , Cemento Dental/efectos de los fármacos , Cemento Dental/patología , Perros , Inserción Epitelial/patología , Factor 2 de Crecimiento de Fibroblastos/genética , Recesión Gingival/patología , Humanos , Masculino , Modelos Animales , Ligamento Periodontal/diagnóstico por imagen , Ligamento Periodontal/patología , Radiografía Dental , Proteínas Recombinantes/genética , Aplanamiento de la Raíz , Andamios del Tejido , Ápice del Diente/diagnóstico por imagen , Ápice del Diente/patología , Cicatrización de Heridas , Microtomografía por Rayos XRESUMEN
BACKGROUND AND OBJECTIVE: Fibroblast growth factor-2 (FGF-2) regulates the proliferation and differentiation of osteogenic cells, resulting in the promotion of bone formation. Biodegradable gelatin sponges incorporating ß-tricalcium phosphate (ß-TCP) have been reported as a scaffold, which has the ability to control growth factor release, offering sufficient mechanical strength and efficient migration of mesenchymal cells. In this study, we evaluated the effects of the combined use of recombinant human FGF-2 (rhFGF-2) and gelatin/ß-TCP sponge on ridge augmentation in dogs. MATERIAL AND METHODS: Six male beagle dogs were used in this study. Twelve wk after tooth extraction, bilateral 10 × 5 mm (width × depth) saddle-type defects were created 3 mm apart from the mesial side of the maxillary canine. At the experimental sites, the defects were filled with gelatin/ß-TCP sponge infiltrated with 0.3% rhFGF-2, whereas gelatin/ß-TCP sponge infiltrated with saline was applied to the control sites. Eight wk after surgery, qualitative and quantitative analyses were performed. RESULTS: There were no signs of clinical inflammation at 8 wk after surgery. Histometric measurements revealed that new bone height at the experimental sites (2.98 ± 0.65 mm) was significantly greater than that at the control sites (1.56 ± 0.66 mm; p = 0.004). The total tissue height was greater at the experimental sites (6.62 ± 0.66 mm) than that at the control sites (5.95 ± 0.74 mm), although there was no statistical significant difference (p = 0.051). Cast model measurements revealed that the residual defect height at the experimental sites (2.31 ± 0.50 mm) was significantly smaller than that at the control sites (3.51 ± 0.78 mm; p = 0.012). CONCLUSION: The combined use of rhFGF-2 and gelatin/ß-TCP sponge promotes ridge augmentation in canine saddle-type bone defects.
Asunto(s)
Factor 2 de Crecimiento de Fibroblastos/uso terapéutico , Animales , Regeneración Ósea , Fosfatos de Calcio , Perros , Gelatina , Humanos , Masculino , OsteogénesisRESUMEN
BACKGROUND AND OBJECTIVE: Tissue regeneration is affected by the porosity, chemical properties and geometric structure of graft materials. Regeneration of severe periodontal defects, such as one-wall intrabony defects, is difficult because of reduced tissue support, and bone grafts are commonly used in such cases. In the present study, a tunnel-structured ß-tricalcium phosphate (tunnel ß-TCP) graft material designed to stimulate bone formation was fabricated. The objective of this pilot study was to evaluate the effect of this graft material on periodontal regeneration in one-wall intrabony defects in dogs. MATERIAL AND METHODS: Six male beagle dogs were used in this study. First, the mandibular second and third incisors were extracted. Experimental surgery was performed 12 wk after tooth extraction. Bilateral 4 × 8 mm (width × depth) one-wall intrabony defects were created in the mesial side of the mandibular canines. At the experimental sites, the defects were filled with tunnel ß-TCP, whereas the control defects were left empty. Twelve weeks after surgery, qualitative and quantitative histological analyses were performed. RESULTS: There were no signs of clinical inflammation 12 wk after surgery. Coronal extension indicative of new bone formation was higher at the experimental sites than at the control sites, although the differences between both the sites in the newly formed cementum and connective tissue attachment were not significant. Newly formed periodontal ligament and cementum-like tissue were evident along the root surface at the experimental sites. The inner surface of the tunnels was partially resorbed and replaced with new bone. New blood vessels were observed inside the lumens of tunnel ß-TCP. CONCLUSION: Tunnel ß-TCP serves as a scaffold for new bone formation in one-wall intrabony defects.
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Pérdida de Hueso Alveolar/cirugía , Regeneración Ósea/fisiología , Sustitutos de Huesos/uso terapéutico , Fosfatos de Calcio/uso terapéutico , Andamios del Tejido , Pérdida de Hueso Alveolar/patología , Animales , Sustitutos de Huesos/química , Fosfatos de Calcio/química , Cementogénesis/fisiología , Colágeno , Tejido Conectivo/patología , Tejido Conectivo/fisiopatología , Diente Canino/patología , Perros , Imagenología Tridimensional/métodos , Masculino , Enfermedades Mandibulares/patología , Enfermedades Mandibulares/cirugía , Neovascularización Fisiológica/fisiología , Osteogénesis/fisiología , Ligamento Periodontal/patología , Ligamento Periodontal/fisiopatología , Proyectos Piloto , Factores de Tiempo , Andamios del Tejido/química , Microtomografía por Rayos X/métodosRESUMEN
The purpose of this study was to observe the variations of cervical curvature in patients with infraocclusion, and to compare this with the controls. In this study, the infraocclusion criteria were defined with the Pr-id as <17 mm on the cephalometric image. The subjects were 32 patients with infraocclusion, and 28 controls which matched the distribution for gender and age. The six points of inquiry were as follows: (i) cervical vertebra height, (ii) neck alignment, (iii) ratio of lower facial height, (iv) vertical dimension of occlusion, (v) cervical angle and (vi) occlusal angle. In over 90% of the patients with infraocclusion, the cervical curvature was classified as straight or kyphosis. Conversely, in 36% of the control subjects, the cervical curvature was classified as lordosis. There was a weak positive correlation between the vertical dimension of occlusion and the cervical curvature in all subjects. In the control group, there was a significant and strong positive correlation between the age and cervical curvature, and a strong negative correlation between age and cervical angle and occlusal angle. Conversely, in the patients with infraocclusion, age was only correlated with the ratio of lower facial height. The prevalence of non-lordosis in the patients with infraocclusion was higher in comparison with the control group in our study, and the previous large-scale study of Japanese. However, there was merely a weak positive correlation between the cervical curvature and the vertical dimension of occlusion.
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Vértebras Cervicales/fisiopatología , Electromiografía , Cifosis/diagnóstico , Lordosis/diagnóstico , Maloclusión/diagnóstico , Dimensión Vertical , Adulto , Anciano , Anciano de 80 o más Años , Pueblo Asiatico , Femenino , Humanos , Japón , Cifosis/clasificación , Cifosis/fisiopatología , Lordosis/clasificación , Lordosis/fisiopatología , Masculino , Maloclusión/fisiopatología , Persona de Mediana Edad , Postura , Resultado del TratamientoAsunto(s)
Dedos/patología , Hipergammaglobulinemia/patología , Inmunoglobulina G/metabolismo , Púrpura/patología , Enfermedad de Raynaud/patología , Anciano , Femenino , Gangrena/etiología , Gangrena/patología , Humanos , Hipergammaglobulinemia/complicaciones , Púrpura/etiología , Enfermedad de Raynaud/etiologíaRESUMEN
Osteophytes of the cervical spine are usually seen in elderly adults. When prominent, they have been blamed for dysphagia, cough, dysphonia and dyspnoea. This paper reports on an obstructive sleep apnoea (OSA) patient with cervical spinal osteophytes, one cause of airway obstruction. A 75-year-old male complained of pronounced snoring. The diagnosis was mild OSA, apnoea hypopnoea index was 9.4. Patient reported no restrictions in neck movements, experiences of neck pain or neck trauma. Previously, patient underwent a tonsillectomy due to discomfort in the pharyngeal region. A lateral cephalometric image was taken to observe airway before oral appliance therapy. The image revealed the presence of large osteophytes or sclerotic enthesopathy, lying on anterior surfaces from the fourth to seventh cervical vertebrae. A computed tomography (CT) image revealed the relationship of airway position to the spine. In the reconstructed three-dimensional (3D) image, the airway appeared displaced to the right of the craniomandiblar bone, with the hyoid bone similarly displaced in a manner to that of the airway. The spine also appeared displaced to the left side ofcraniomandiblar bone. Additionally, the 3D image revealed calcification of the stylohyoideum ligament and ligamentum nuchae. This present case highlights the necessity of CT examination for OSA patients. There were several ligament calcifications in the head and neck region. Cervical spine osteophytes, as a component of Forestier's or cervical spine disease, have been associated with dysphagia and dysphonia. It was reported that bilateral vocal cord paralysis was caused by osteophytes compressing the post-cricoid area of larynx.
Asunto(s)
Vértebras Cervicales/diagnóstico por imagen , Apnea Obstructiva del Sueño/diagnóstico por imagen , Ronquido/diagnóstico por imagen , Osteofitosis Vertebral/diagnóstico por imagen , Anciano , Humanos , Masculino , Apnea Obstructiva del Sueño/etiología , Ronquido/etiología , Osteofitosis Vertebral/complicaciones , Tomografía Computarizada por Rayos XRESUMEN
A Multiple Simulation System can provide useful insight to clinical diagnosis and treatment. However, when metal prostheses are present in the patient, the quality of the CT is greatly reduced, resulting in an image that is distorted and thus provides little understanding on extraction and form of dentition. In order to circumvent this, we scanned the surface of a plaster dental model with a 3-D scanner. Subsequently, this model was digitally combined with the CT reconstruction model, and used as a guide to remove any disturbances that were due to the presence of metal artifacts. The VR and physical occlusal contacts were accorded about 55%. Subsequently, we were able to reproduce a skull model specific to the patient occlusal contacts. This was verified via color mapping. In addition, this system was able to provide a quantitative clinical and dental evaluation of the teeth adjustment configuration.
Asunto(s)
Simulación por Computador , Dentición , Imagenología Tridimensional/normas , Mandíbula , Maxilar , Humanos , Procesamiento de Imagen Asistido por Computador/métodosRESUMEN
Amelogenin is the major enamel matrix component in developing teeth. In eutherian mammals, amelogenin is expressed from the X chromosome only, or from both the X and Y chromosomes. Two classes of porcine amelogenin cDNA clones have been characterized, but the chromosomal localization of the gene(s) encoding them is unknown. To determine if there are sex-based differences in the expression of porcine amelogenin, we paired PCR primers for exons 1a, 1b, 7a, and 7b, and amplified enamel organ-derived cDNA separately from porcine males and females. The results show that exons 1a/2a and 7a are always together and can be amplified from both males (XY) and females (XX). Exons 1b/2b and 7b are also always paired, but can be amplified only from females. We conclude that porcine amelogenin is expressed from separate genes on the X and Y chromosomes, and not, as previously proposed, from a single gene with two promoters.
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Proteínas del Esmalte Dental/genética , Órgano del Esmalte/metabolismo , Germen Dentario/metabolismo , Cromosoma X/metabolismo , Cromosoma Y/metabolismo , Amelogenina , Animales , Mapeo Cromosómico , Proteínas del Esmalte Dental/metabolismo , Exones/genética , Femenino , Incisivo , Masculino , Mandíbula , ARN/análisis , Factores Sexuales , Porcinos , Cromosoma X/genética , Cromosoma Y/genéticaRESUMEN
We have previously described how T and natural killer (NK) lineage commitment proceeds from common T/NK progenitors (p-T/NK) in the murine fetal thymus (FT), with the use of a clonal assay system capable of discriminating p-T/NK from unipotent T or NK lineage-committed progenitors (p-T and p-NK, respectively). The molecular mechanisms controlling the commitment processes, however, are yet to be defined. In this study, we investigated the progenitor activity of FT cells from Id2-/- mice that exhibit defective NK cell development. In the Id2-/- FT, NK cells were greatly reduced, and a cell population that exclusively contains p-NK in the wild-type thymus was completely missing. Id2-/- FT progenitors were unable to differentiate into NK cells in IL-2-supplemented-FT organ culture. Single progenitor analysis demonstrated that all Id2-/- fetal thymic progenitors are destined for the T cell lineage, whereas progenitors for T/NK, T, and NK cell lineages were found in the control. Interestingly, the total progenitor number was similar between Id2-/- and Id2+/+ embryos analyzed. Expression of Id2 was correlated with p-NK activity. Our results suggest that Id2 is indispensable in thymic NK cell development, where it most probably restricts bipotent T/NK progenitors to the NK cell lineage.
Asunto(s)
Diferenciación Celular , Proteínas de Unión al ADN/metabolismo , Secuencias Hélice-Asa-Hélice , Células Asesinas Naturales/citología , Proteínas Represoras , Factores de Transcripción , Animales , Diferenciación Celular/efectos de los fármacos , Linaje de la Célula/efectos de los fármacos , Células Cultivadas , Proteínas de Unión al ADN/química , Proteínas de Unión al ADN/genética , Citometría de Flujo , Eliminación de Gen , Receptores de Hialuranos/metabolismo , Proteína 2 Inhibidora de la Diferenciación , Interleucina-2/farmacología , Células Asesinas Naturales/efectos de los fármacos , Células Asesinas Naturales/metabolismo , Recuento de Linfocitos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Modelos Inmunológicos , Técnicas de Cultivo de Órganos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptores de Interleucina-2/análisis , Receptores de Interleucina-2/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Madre/citología , Células Madre/efectos de los fármacos , Células Madre/metabolismo , Timo/citología , Timo/efectos de los fármacos , Timo/embriología , Timo/metabolismoRESUMEN
Previous studies indicated that multipotent progenitors exist in early fetuses that do not contain long-term reconstituting (LTR) activity. However, it remained unclear whether these multipotent progenitors are committed to the hemopoietic lineage or are immature mesodermal cells or hemangioblasts. In this study, we have succeeded in enriching the multipotent progenitors that are capable of generating myeloid, T, and B cells in the LFA-1(-) subpopulation of TER-119(-)c-kit(+)CD45(+) cells from the aorta-gonad-mesonephros (AGM) region of day 10 fetuses. We found that these day 10 AGM LFA-1(-) cells do not show the LTR activity, whereas day 11 AGM LFA-1(-) cells do have such an activity. These results strongly suggest that multipotent progenitors lacking LTR activity emerge as CD45(+) hemopoietic progenitor cells in the AGM region on the 10th day of gestation, and such p-Multi mature into hemopoietic stem cells by acquiring LTR activity.
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Médula Ósea/metabolismo , Embrión de Mamíferos/citología , Embrión de Mamíferos/metabolismo , Proteínas de Escherichia coli , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/metabolismo , Animales , Aorta/citología , Aorta/embriología , Aorta/inmunología , Médula Ósea/inmunología , Diferenciación Celular/inmunología , División Celular/inmunología , Línea Celular , Linaje de la Célula/inmunología , Células Cultivadas , Ensayo de Unidades Formadoras de Colonias , Copulación , Proteínas de Unión al ADN/biosíntesis , Embrión de Mamíferos/inmunología , Desarrollo Embrionario y Fetal/inmunología , Gónadas/citología , Gónadas/embriología , Gónadas/inmunología , Trasplante de Células Madre Hematopoyéticas , Células Madre Hematopoyéticas/inmunología , Antígenos Comunes de Leucocito/biosíntesis , Recuento de Leucocitos , Antígeno-1 Asociado a Función de Linfocito/biosíntesis , Mesonefro/citología , Mesonefro/embriología , Mesonefro/inmunología , Ratones , Ratones Endogámicos C57BL , Proteínas Proto-Oncogénicas c-kit/biosíntesisRESUMEN
Purification of mannitol-l-phosphatase, an enzyme catalyzing the final step of mannitol biosynthesis, was first achieved in the mannitol-accumulating red alga Caloglossa continua (Okamura) King et Puttock. The enzyme was shown to be a monomer, since gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis gave close values of apparent molecular weights of 28,500 and 30,200, respectively. The protein exhibited an isoelectric point of 4.8. The substrate specificity for mannitol-l-phosphate (MIP) was very high, and that for K(m)(MIP) was 0.41 mM. The catalytic activity was optimal at pH 7.4. The enzyme was activated by Mg(2+), but was strongly inhibited by Ca(2+), NaF, N-ethylmaleimide, and p-hydroxymercuribenzoic acid. Seawater levels of NaCl and physiological levels of mannitol also inhibited the activity by 50% or more. Changes in the concentrations of those ions and metabolites may regulate the biosynthesis of mannitol as an osmoregulant in vivo.
RESUMEN
A new type of glycolate-oxidizing enzyme was found in the prasinophycean alga Mesostigma viride. This enzyme was characterized as the glycolate oxidase that strongly requires FMN, thus distinguishing it from most other Prasinophytes that possess glycolate dehydrogenase instead.
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Oxidorreductasas de Alcohol/metabolismo , Chlorophyta/enzimología , Mononucleótido de Flavina/metabolismo , Oxidorreductasas de Alcohol/aislamiento & purificación , Glicolatos/metabolismo , Cinética , Oxidación-Reducción , Especificidad por SustratoRESUMEN
The developmental potential of individual cells in the Lin-c-kit+CD45+IL-7R+ (IL-7R+) population from murine fetal liver was investigated using a clonal assay capable of determining the potential of a progenitor to give rise to myeloid, T, and B cells. Unipotent progenitors generating T cells (p-T) or B cells (p-B) but not other types of progenitors were found in the IL-7R+ population. A large proportion of progenitors at day 12 of gestation are p-T, whereas the frequency of p-T dramatically decreases with gestational age. In marked contrast, p-B are very rare by day 12, but they rapidly increase thereafter. These findings strongly suggest that the commitment of multipotent progenitors to T and B cell lineages occurs independently.
Asunto(s)
Linfocitos B/citología , Hematopoyesis Extramedular , Células Madre Hematopoyéticas/citología , Hígado/embriología , Linfocitos T/citología , Animales , Antígenos de Diferenciación de Linfocitos T/análisis , Linaje de la Célula , Ensayo de Unidades Formadoras de Colonias , Desarrollo Embrionario y Fetal , Edad Gestacional , Antígenos Comunes de Leucocito/análisis , Hígado/citología , Hígado/fisiología , Ratones , Ratones Endogámicos BALB C , Proteínas Proto-Oncogénicas c-kit/análisis , Receptores de Interleucina-7/análisisRESUMEN
We have established a new clonal assay system that can evenly support the development of T and natural killer (NK) cells. With this system, we show that all T cell progenitors in the earliest CD44(+)CD25(-)FcgammaRII/III(-) fetal thymus (FT) cell population retain NK potential, and that the NK lineage-committed progenitors (p-NK) also exist in this population. T cell lineage-committed progenitors (p-T), which are unable to generate NK cells, first appear at the CD44(+)CD25(-) FcgammaRII/III(+) stage in day 12 FT. The proportion of p-T markedly increases during the transition from the CD44(+)CD25(-) stage to the CD44(+)CD25(+) stage in day 14 FT. On the other hand, p-NK preferentially increase in number at the CD44(+)CD25(-) stage between days 12 and 14 of gestation. The production of p-NK continues up to the CD44(+)CD25(+) stage, but ceases before the rearrangement of T cell receptor beta chain genes. It was further shown that the CD44(+)CD25(-) CD122(+) population of day 14 FT exclusively contains p-NK. These results indicate that the earliest T cell progenitor migrating into the FT is T/NK bipotent, and strongly suggest that the bipotent progenitor continuously produces p-NK and p-T until the CD44(+)CD25(+) stage.
Asunto(s)
Citocinas/farmacología , Células Madre Hematopoyéticas/inmunología , Interleucinas/farmacología , Células Asesinas Naturales/inmunología , Linfocitos T/inmunología , Timo/embriología , Animales , Antígenos de Diferenciación de Linfocitos T/análisis , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/inmunología , Feto , Citometría de Flujo , Células Madre Hematopoyéticas/efectos de los fármacos , Inmunofenotipificación , Ratones , Ratones Endogámicos C57BL , Técnicas de Cultivo de Órganos , Proteínas Recombinantes/farmacología , Timo/inmunologíaRESUMEN
We have analyzed proteasomal adaptation and associated changes in the B27-bound peptide repertoire in response to cellular invasion with Salmonella. The peptide repertoire of HLA-B27 complexes was analyzed by two different methods: (i) high-pressure liquid chromatography (HPLC) profiles of newly synthesized peptides eluted from B27 following metabolic labeling with arginine and (ii) reactivities with two B27 monoclonal antibodies, Ye-2 and B27.M2, sensitive to peptide-induced conformational changes. LMP, MECL, and PA28 expression was analyzed by reverse transcription-PCR (RT-PCR) of mRNA and by Western blot analysis for LMP2. Invasion of HLA-B27-transfected HeLa cells by Salmonella typhimurium induced significant changes in the reactivities of HLA-B27 with these two antibodies, which was accompanied by significant quantitative and qualitative changes in the HPLC profile of peptides eluted from HLA-B27. We also observed increases in the RT-PCR values for the LMP2, LMP7, and MECL proteasome subunit genes, as well as the proteasomal activator PA28alpha and -beta genes, and increased expression of the LMP2 protein by Western blotting. Upregulation of LMP2, but not LMP7, gene expression showed a close correlation with the changes in antibody reactivities observed upon bacterial invasion. We observed similar changes in reactivity with the Ye-2 or the B27.M2 antibody of lymphoblastoid cells upon gamma interferon treatment, which significantly correlated with the increased RT-PCR values for the LMP2 gene. This was accompanied by consistent HPLC profile changes for eluted peptides. Thus, Salmonella invasion leads to serologically recognizable changes in the B27-bound peptide repertoire, which may include peptides of host origin potentially through modulation of proteasome LMP2 subunit expression and, as a consequence, proteasomal activities.
Asunto(s)
Cisteína Endopeptidasas/metabolismo , Antígeno HLA-B27/inmunología , Complejos Multienzimáticos/metabolismo , Proteínas Musculares , Péptidos/metabolismo , Salmonella typhimurium/inmunología , Presentación de Antígeno , Cisteína Endopeptidasas/biosíntesis , Citotoxicidad Inmunológica , Regulación Enzimológica de la Expresión Génica , Humanos , Interferón gamma/farmacología , Complejo de la Endopetidasa Proteasomal , Unión Proteica , Biosíntesis de Proteínas , Conformación Proteica , Salmonella typhimurium/patogenicidad , Células Tumorales CultivadasRESUMEN
HLA-B27 confers a very strong genetic predisposition to development of a reactive arthritis after infection by bacteria such as Salmonella typhimurium. This study examines the role of HLA-B27 in the initiation of the earliest host activities after exposure to Salmonella, namely activation of the immediate early genes in the epithelial cells. Our major finding is that in Hela cells, the expression of c-fos was induced by Salmonella invasion only when the cells expressed the transfected HLA-B27 gene, but not the HLA-A1 gene or a truncated HLA-B27 gene lacking the exons encoding the cytoplasmic domain. C-fos is potentially capable of complexing with members of the c-jun family to become the AP-1 transcription complex. Parallel to c-fos expression, we found that only with the HLA-B27 transfectant was there expression of AP-1. AP-1 potentially controls the expression of a large number of genes. On screening a panel of proinflammatory molecules, we found that Salmonella invasion induced expression of monocyte chemoattractant protein-1 in the HLA-B27 cells. Since each of these separate positive findings belong to the same cascade of events after cell activation, together they reinforce the hypothesis that HLA-B27 plays a modulatory role in the early signal transduction events induced by Salmonella invasion. This hypothesis adds another item to the list of allele-specific activities carried out by HLA class I molecules. If similar activation also occurs in the joints, it may play a major role in arthritis.
Asunto(s)
Artritis/inmunología , Antígeno HLA-B27/biosíntesis , Proteínas Proto-Oncogénicas c-fos/biosíntesis , Salmonella typhimurium/fisiología , Quimiocina CCL2/biosíntesis , Expresión Génica , Antígeno HLA-B27/genética , Células HeLa , Humanos , Regiones Promotoras Genéticas , Proteínas Proto-Oncogénicas c-fos/genética , Salmonella typhimurium/crecimiento & desarrollo , Factor de Transcripción AP-1/genética , Factores de Transcripción/metabolismo , TransfecciónRESUMEN
OBJECTIVE: Alternative splicing of certain class I major histocompatibility complex pre-messenger RNA (pre-mRNA) is known to lead to generation of a cell-free soluble protein analog. This study was undertaken to examine whether this process occurs with HLA-B27, whether the process is modified by arthritis-causing bacteria, and whether the assembly of the soluble molecules follows the same pathway as the integral parent molecules. METHODS: Alternative splicing of pre-mRNA was analyzed by reverse transcriptase-polymerase chain reaction, and assembly of soluble HLA-B27 by immunoprecipitation followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. RESULTS: There was alternative splicing of the pre-mRNA of HLA-B27. The process could be amplified by invasion with Salmonella or Yersinia bacteria. The soluble HLA-B27 was assembled in a pathway similar to that of the parent molecule. CONCLUSION: The association between arthritis-causing bacteria and HLA-B27 positive cells is a complex event. Soluble HLA-B27 is a potential key player.
Asunto(s)
Empalme Alternativo/fisiología , Antígeno HLA-B27/genética , Salmonella typhimurium/fisiología , Yersinia enterocolitica/fisiología , Secuencia de Bases , Línea Celular/microbiología , Células Cultivadas , Cartilla de ADN/química , Electroforesis en Gel de Poliacrilamida , Antígeno HLA-B27/biosíntesis , Humanos , Linfocitos/citología , Linfocitos/metabolismo , Linfocitos/microbiología , Datos de Secuencia Molecular , Monocitos/citología , Monocitos/metabolismo , Monocitos/microbiología , Reacción en Cadena de la Polimerasa , ARN Bacteriano/genética , TransfecciónRESUMEN
A painless and progressively growing mass consisting of fibronecrotic quadriceps femoris muscles with a giant multilobular cystic cavity formed 15 years after total knee arthroplasty for Charcot joint. It was considered to be a cyst from the knee joint accompanied by compartmental muscular necrosis. The painless and progressively growing nature of the mass seemed to be largely attributable to a neuropathic joint. Computed tomography proved to be helpful for diagnosis. Conservative management was unsuccessful in relieving the symptoms.