Sclerotic Zone Research Articles

Bone lesions in systemic lupus erythematosus.

Routine joint radiographs of 125 patients with systemic lupus erythematosus were studied. A total of 121 patients had a clinical history of articular symptoms. Cystic bone lesions were found in 51 patients (41%). The lesions, which were typically located subchondrally in the small joints of hands and feet, appeared as well-defined radiolucent areas surrounded by either normal bone or a narrow sclerotic zone. Nutritional disturbance in the bones, caused by the vasculitis associated with systemic lupus erythematosus, is proposed as a possible pathogenetic mechanism of the cystic lesions.

The intermediate filament cytoskeleton of myofibroblasts: an immunofluorescence and ultrastructural study.

The intermediate filament cytoskeleton of stromal myofibroblasts from a series of twenty-eight infiltrating ductal breast carcinomas was examined by transmission electron microscopy (TEM) and indirect immunofluorescence (IF), the latter using antibodies to desmin, vimentin and prekeratin. Three cases of fibromatoses, selected as an additional source of myofibroblasts, were processed in the same manner. Stromal myofibroblasts from invasive ductal breast carcinomas rich in actin and readily identified by IF, were most numerous in the "young" edematous mesenchyme, areas corresponding to early stromal invasion or the peripheral invasive cellular front. Within the central sclerotic zone wherein clusters of neoplastic epithelial cells were surrounded by abundant collagen, most stromal cells corresponded by TEM to fibroblasts. In like fashion, myofibroblasts were most numerous in cellular, poorly collagenized portions of fibromatoses. By IF the only detectable intermediate filament protein of myofibroblasts in these two settings was vimentin. Since the appearance of stromal myofibroblasts appears to be associated with stromal invasion by malignant epithelium, their development by modulation of pre-existent periductal fibroblasts is postulated. With the exception of vascular smooth muscle cells and endothelial cells, the only periductal mesenchymal cells shown to contain vimentin were fibroblasts. The lack of desmin in myofibroblasts constitutes evidence against an origin from vascular smooth muscle cells. Because the molecular markers (intermediate filament proteins) of stromal cell differentiation presented quantitative but not qualitative modifications, the transformation of fibroblasts into myofibroblasts is quite likely, suggesting that myofibroblasts may be more closely related to fibroblasts than to smooth muscle cells.

Development of carpal bone cysts as revealed by radiography.

In 11 patients with carpal bone cysts the course of the intraosseous lytic lesion could be followed over periods from 2 to 27 years. The cysts were found to develop from an area of sparse trabeculae of reduced mineral content to a well-defined cavity, in some instances surrounded by a sclerotic zone. In 2 instances the lytic process caused progressive destruction of the subchondral layers of the affected bone resulting in communication with the adjacent joint space. The findings support the theory that carpal bone cysts are intraosseous lesions probably caused by vascular disturbances from mechanical stress and repeated trauma. The term intraosseous ganglion is a misnomer and should be avoided.

The amount and distribution of sclerotic human root dentine

In low-power photomicrographs of ground sections of canine teeth, the amount of sclerosis increased with age linearly and was not markedly affected by the function of the tooth or external stimuli encountered during life. The pattern of distribution was similar in all teeth. Sclerosis started in the apical dentine adjacent to the cementum and extended coronally and towards the root canal, with increasing age. In the plane transverse to the long axis of the root, sclerosis appeared first at the mesial and distal sides so that the sclerotic zones formed a butterfly shape.

The Coal-Age Flora of Kansas. III. Psaronius cooksonii a New Species Showing Caulopteris Features

1. A well-preserved silicified specimen of the genus Psaronius, showing both the internal anatomy and the external features of Caulopteris, is described (as P. cooksonii) from the Kansas Wabaunsee group, Upper Pennsylvanian. 2. Anatomically, it is characterized by twelve foliar bundles alternating with twelve peripheral bundles. The leaf scars are in twelve vertical rows arranged in alternating whorls of six leaves each. Evidence is presented to show that the pattern of the leaf trace scar varies (depending on the distance from the base of the petiole) from a straight band to a U-shape, then to an oval-shape, and finally to an oval with an inclosed inverted V. It is also pointed out that when the Caulopteris surface is free from the usual sheath of adventitious roots, the leaf vascular bundle scar is visible only as a slightly curved band within the base of the protruding petiole scar, its higher configurations being simulated by the fissure between inner parenchyma and outer sclerotic zones of the petiole.