RESUMEN
The amino acid sequences of 21 beta-glycanases have been compared by hydrophobic cluster analysis. Six families of cellulases have been identified on the basis of primary structure homology: (A) endoglucanases B, C and E of Clostridium thermocellum; endoglucanases of Erwinia chrysanthemi and Bacillus sp.; endoglucanase III of Trichoderma reesei; endoglucanase I of Schizophyllum commune; (B) cellobiohydrolase II of T. reesei; endoglucanases of Cellulomonas fimi and Streptomyces sp; (C) cellobiohydrolases I of T. reesei and of Phanerochaete chrysosporium; endoglucanase I of T. reesei; (D) endoglucanase A of C. thermocellum and an endoglucanase from Ce. uda; (E) endoglucanase D of C. thermocellum and an endoglucanase from Pseudomonas fluorescens; (F) xylanases of C. thermocellum and of Cryptococcus albidus and the cellobio-hydrolase of Ce. fimi. For each family, conserved potentially catalytic residues have have been listed and previous allocations of the active-site residues are evaluated in the light of the alignment of the amino acid sequences. A strong homology is also reported for the putative cellulose-binding domains of cellulases of Ce. fimi and of P. fluorescens.
Asunto(s)
Celulasa/clasificación , Análisis por Conglomerados , Secuencia de Aminoácidos , Bacterias/enzimología , Bacterias/genética , Sitios de Unión , Celulasa/genética , Datos de Secuencia Molecular , Conformación Proteica , Homología de Secuencia de Ácido Nucleico , SolubilidadRESUMEN
The authors report an exceptional case of giant cell tumour of the third thoracic vertebra revealed by its mediastinal development. Despite intimate involvement of the large mediastinal vessels, a double surgical approach, starting with sternotomy to ensure vascular control then anterolateral thoracotomy, allowed curative resection of this tumor. Treatment was completed by a second neurosurgical operation followed by 5,000 rads of radiotherapy. Based on a review of the literature, the authors discuss the pathogenesis and consider the various therapeutic problems raised by giant cell tumours of the vertebrae (situated above the sacrum).
Asunto(s)
Neoplasias Óseas/cirugía , Tumores de Células Gigantes/cirugía , Neoplasias del Mediastino/cirugía , Adulto , Neoplasias Óseas/diagnóstico por imagen , Neoplasias Óseas/radioterapia , Terapia Combinada , Tumores de Células Gigantes/diagnóstico por imagen , Tumores de Células Gigantes/radioterapia , Humanos , Imagen por Resonancia Magnética , Masculino , Neoplasias del Mediastino/diagnóstico por imagen , Neoplasias del Mediastino/radioterapia , Dosis de Radiación , Radiografía , ToracotomíaRESUMEN
In a poorly equipped tropical setting, limb amputation is often considered as the only therapeutic solution for malignant tumors or large benign tumors. However it can be avoided by bone replacement using an avascular autologous fibular graft. This method was used in a young girl from Tchad presenting a giant cavernous hemangioma of the humerus. This technique allowed salvage of the extremity but resulted inevitably in radial paralysis. The time needed for bone healing was normal. This technique required minimum facilities and was perfectly biocompatible. It can be used in tropical settings where allograft techniques and prosthetic replacement are not available.
Asunto(s)
Neoplasias Óseas/cirugía , Trasplante Óseo/métodos , Hemangioma Cavernoso/cirugía , Húmero , Neoplasias Óseas/diagnóstico por imagen , Neoplasias Óseas/patología , Placas Óseas , Tornillos Óseos , Niño , Femenino , Peroné/trasplante , Hemangioma Cavernoso/diagnóstico por imagen , Hemangioma Cavernoso/patología , Humanos , Osteotomía/métodos , Parálisis/etiología , Complicaciones Posoperatorias/etiología , Nervio Radial/lesiones , Radiografía , Medicina Tropical , Cicatrización de HeridasRESUMEN
The catheter of an implantable chamber migrated into the pulmonary infundibulum in a patient given chemotherapy for bronchogenic cancer. Current management of such cases is to remove the catheter under pulmonary angiography control using a basket system.