ABSTRACT
The aneurysmal bone cyst is a rare tumor. Its treatment is complex when localized to the lumbar spine, with neurological, mechanical, and tumoral complications. The aim of this study is to describe these tumors, their treatment, and their long-term evolution, as well as to define an appropriate therapeutic strategy. Four of the five cysts had anterior and posterior extension. Three patients had neurological symptoms at diagnosis and two of them presented with pathological fracture. Surgical treatment was performed by intralesional resection. Long-term progress was always favorable, without recurrence or functional limitation. Two patients had a stable, mild spine deformity.
Subject(s)
Bone Cysts, Aneurysmal/pathology , Bone Cysts, Aneurysmal/surgery , Lumbar Vertebrae/pathology , Lumbar Vertebrae/surgery , Adolescent , Bone Cysts, Aneurysmal/complications , Child , Child, Preschool , Female , Fractures, Spontaneous/diagnosis , Fractures, Spontaneous/etiology , Humans , Male , Nervous System Diseases/diagnosis , Nervous System Diseases/etiology , Postoperative Complications , Recovery of Function , Retrospective Studies , Treatment OutcomeABSTRACT
Enchondromas are common intraosseous usually benign cartilaginous tumors that develop in close proximity to growth plate cartilage. Genochondromatosis is a familial skeletal condition with autosomal dominant inheritance pattern. Genochondromatosis type I is a skeletal disorder characterized by symmetrical chondromatosis with characteristic localization: clavicle, upper end of humerus, and lower end of femur. The condition shows a benign course and is clearly different from metachondromatosis, generalized enchondromatosis, and spondyloenchondrodysplasia. In contrast, genochondromatosis type II is characterized by normal clavicles, but metaphyseal involvement of the hands, feet, knees, and wrists. To date, one family has been described with two affected individuals and possibly a second one with seven affected individuals. We report here on a boy with radiographic features of genochondromatosis type II. This report confirms that this disorder represents a separate clinical entity distinguishable for genochondromatosis type I. In addition, this report confirms the benign course of this rare disorder and will help accurate genetic counseling.
Subject(s)
Enchondromatosis/diagnostic imaging , Enchondromatosis/genetics , Child , Humans , Male , Phenotype , RadiographyABSTRACT
Melatonin is synthesized by a series of enzymes, the penultimate one, serotonin N-acetyltransferase, catalyzing the limiting reaction. In the present study, we compared the recombinant serotonin N-acetyltransferases from rat, ovine, and human. The human protein is particularly difficult to purify because it interacts strongly with a putative chaperone protein from bacteria whereas the rat and sheep enzymes, which interact less strongly with this protein, have been purified close to homogeneity. We identified the contaminating protein as GroEL, the bacterial equivalent of Hsp60. We present numerous catalytic activities (substrate and cosubstrate specificities as well as inhibitor specificities) measured on the three species enzymes from which we deduced that the presence of the chaperone might partly explain the differences between the various species enzyme characteristics, beside the inter-species ones resulting from sequence differences. Despite several trials reported in the literature, a purification to homogeneity of the human (recombinant) enzyme has never been described. We present a new purification method, by using an original denaturation/renaturation process in which the enzyme is immobilized on an affinity chromatography column. The enzyme is then eluted in an active and pure form (i.e., absence of chaperone). The up-scaled system permitted us to perform the necessary experiments for the measurement of more accurate affinities of human serotonin N-acetyltransferase towards its main natural substrates, showing that only the activity of the enzyme towards phenylethylamine was modified.
