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(1/101) Erdheim-Chester disease: a case report.

A 42-year-old man with Erdheim-Chester disease (EC) is presented. This is the first case of this disease reported in Korea. The patient complained of knee pain and plain roentgenogram of the bilateral legs revealed diffusely increased density, coarsened trabecular pattern, and cortical thickening in the diaphysis, and metaphysis as well as epiphysis. Magnetic resonance imaging revealed that the lesions showed low signal intensity on T1-weighted images and heterogeneously low and high signal intensity on T2-weighted images. Histological examination of the biopsy specimen showed a xanthogranulomatous lesion consisting aggregations of foamy histiocytes and Touton-type giant cells. Immunohistochemical staining showed positive reaction to anti-S-100 and lysozyme in the cytoplasm of the giant cells.  (+info)

(2/101) Onset and dynamics of osteosclerosis in mice induced by Reilly-Finkel-Biskis (RFB) murine leukemia virus. Increase in bone mass precedes lymphomagenesis.

Newborn NMRI strain mice were infected with Reilly-Finkel-Biskis (RFB) murine leukemia virus (MuLV), a murine leukemia virus that has been shown to induce lymphomas, osteosclerosis, and osteomas in susceptible strains of mice. Bone histomorphometry of the distal femoral metaphyses at 3-month intervals showed osteosclerosis 3 (100%), 6 (100%), and 9 (93%) months after infection. This was represented by significantly augmented cancellous bone mass and accompanied by distinct changes in bone architecture. High numbers of provirus copies were detected at 2-4 weeks in femora, humeri, and calvaria, and viral protein was highly expressed in trabecular and cortical bone cells, particularly in osteocytes. Infected mice showed enhanced bone formation and smaller numbers of osteoclasts relative to sex- and age-matched controls. Osteoclastic differentiation was significantly reduced in cocultures of spleen or bone marrow cells with RFB MuLV-infected osteoclastogenic, osteoblast-like cells. However, RFB MuLV did not impair the activity of mature osteoclasts. In infected mice lymphomas were only observed at 6 (22%) and 9 months (40%) of age. At 3 months, IgG gene and TCR-beta gene rearrangements were not detectable, and new proviruses showed a heterogeneous integration pattern, indicating the absence of lymphoma in early osteosclerotic mice. In contrast, lymphomas, which developed in 8- to 9-month-old infected mice, showed IgG rearrangements indicating development of B-cell lymphomas, together with mono- or oligoclonal expansion of distinct patterns of proviral integrations. These results indicate that RFB MuLV-induced osteosclerosis develops within 3 months after infection and precedes lymphomagenesis. It may therefore be considered an independent skeletal lesion in MuLV-infected mice.  (+info)

(3/101) Mice lacking beta3 integrins are osteosclerotic because of dysfunctional osteoclasts.

Osteoclasts express the alphavbeta3 integrin, an adhesion receptor that has been implicated in bone resorption and that is therefore a potential therapeutic target. To assess the role of this heterodimer in skeletal development in vivo, we engineered mice in which the gene for the beta3 integrin subunit was deleted. Bone marrow macrophages derived from these mutants differentiate in vitro into numerous osteoclasts, thus establishing that alphavbeta3 is not necessary for osteoclast recruitment. Furthermore, the closely related integrin, alphavbeta5, does not substitute for alphavbeta3 during cytokine stimulation or authentic osteoclastogenesis. beta3 knockout mice, but not their heterozygous littermates, develop histologically and radiographically evident osteosclerosis with age. Despite their increased bone mass, beta3-null mice contain 3.5-fold more osteoclasts than do heterozygotes. These mutant osteoclasts are, however, dysfunctional, as evidenced by their reduced ability to resorb whale dentin in vitro and the significant hypocalcemia seen in the knockout mice. The resorptive defect in beta3-deficient osteoclasts may reflect absence of matrix-derived intracellular signals, since their cytoskeleton is distinctly abnormal and they fail to spread in vitro, to form actin rings ex vivo, or to form normal ruffled membranes in vivo. Thus, although it is not required for osteoclastogenesis, the integrin alphavbeta3 is essential for normal osteoclast function.  (+info)

(4/101) Terminal phalageal osteosclerosis.

Osteosclerosis of the terminal finger phalanges was assessed by means of a grading score in two age-matched groups of 96 females, each suffering from rheumatoid arthritis (RA) and osteoarthrosis (OA), respectively, and in a sample of 894 males and females, above the age of 44 years, from Dutch small town populations. Cortical thickness of the therminal phalanges decreases markedly with age. Whereas in the age group 45-54 years, terminal phalangeal osteosclerosis is more pronounced in females, at higher ages the difference between the sexes disappears. The diameter of the terminal cortex increases gradually from the second to the fifth finger. No differences were found between the RA and the OA groups, nor were these groups different from the population survey except for a lower incidence of terminal phalangeal osteosclerosis in female osteoarthrotics between 45 and 55 years of age, compared to females of the same age group from the population sample.  (+info)

(5/101) MR imaging of medullary streaks in osteosclerosis: a case report.

We present a case of medullary sclerosis of the appendicular skeleton in a patient with chronic renal insufficiency for whom MR imaging findings were characteristic. T1- and T2-weighted MR images showed multiple vertical lines (medullary streaks) of low signal intensity in the metaphyses and diaphyses of the distal femur and proximal tibia.  (+info)

(6/101) Bone abnormalities in latent TGF-[beta] binding protein (Ltbp)-3-null mice indicate a role for Ltbp-3 in modulating TGF-[beta] bioavailability.

The TGF-betas are multifunctional proteins whose activities are believed to be controlled by interaction with the latent TGF-beta binding proteins (LTBPs). In spite of substantial effort, the precise in vivo significance of this interaction remains unknown. To examine the role of the Ltbp-3, we made an Ltbp-3-null mutation in the mouse by gene targeting. Homozygous mutant animals develop cranio-facial malformations by day 10. At 2 mo, there is a pronounced rounding of the cranial vault, extension of the mandible beyond the maxilla, and kyphosis. Histological examination of the skulls from null animals revealed ossification of the synchondroses within 2 wk of birth, in contrast to the wild-type synchondroses, which never ossify. Between 6 and 9 mo of age, mutant animals also develop osteosclerosis and osteoarthritis. The pathological changes of the Ltbp-3-null mice are consistent with perturbed TGF-beta signaling in the skull and long bones. These observations give support to the notion that LTBP-3 is important for the control of TGF-beta action. Moreover, the results provide the first in vivo indication for a role of LTBP in modulating TGF-beta bioavailability.  (+info)

(7/101) Stimulation of osteoprotegerin production is responsible for osteosclerosis in mice overexpressing TPO.

Myelofibrosis and osteosclerosis are prominent features arising in mice overexpressing thrombopoietin (TPO). The pivotal role of transforming growth factor beta 1 (TGF-beta 1) in the pathogenesis of myelofibrosis has been documented, but the mechanisms mediating osteosclerosis remain unclear. Here, we used mice deficient in osteoprotegerin (OPG), a secreted inhibitor of bone resorption, to determine whether osteosclerosis occurs through a deregulation of osteoclastogenesis. Marrow cells from opg-deficient mice (opg(-/-)) or wild-type (WT) littermates were infected with a retrovirus encoding TPO and engrafted into an opg(-/-) or WT background for long-term reconstitution. The 4 combinations of graft/host (WT/WT, opg(-/-)/opg(-/-), opg(-/-)/WT, and WT/opg(-/-)) were studied. Elevation of TPO and TGF-beta 1 levels in plasma was similar in the 4 experimental groups and all the mice developed a similar myeloproliferative syndrome associated with severe myelofibrosis. Osteosclerosis developed in WT hosts engrafted with WT or opg(-/-) hematopoietic cells and was associated with increased OPG levels in plasma and decreased osteoclastogenesis. In contrast, opg(-/-) hosts exhibited an osteoporotic phenotype and a growth of bone trabeculae was rarely seen. These findings suggest that osteosclerosis in mice with TPO overexpression occurs predominantly via an up-regulation of OPG in host stromal cells leading to disruption of osteoclastogenesis.  (+info)

(8/101) Decrease of osteosclerosis in subchondral bone of medial compartmental osteoarthritic knee seven to nineteen years after high tibial valgus osteotomy.

Osteosclerosis of the subchondral bone was measured by densitometer on plain radiographs in 55 medial compartmental osteoarthritic knees of 40 patients who were treated with high tibial valgus osteotomy for correction of varus deformity. The ratio of the osteosclerosis value of the medial side of the knee to that of the lateral side (Medial/Lateral ratio) was calculated and used as a parameter. The Medial/Lateral ratio of osteosclerosis decreased rapidly within three years after osteotomy at the reference points of the femur and the tibia. Even 7 to 19 years after osteotomy, a decrease of the ratio was noted in 16 knees with a standing femorotibial angle (FTA) less than 168 degrees (12 degrees of anatomical valgus angulation). This was interpreted to mean that osteosclerosis of the medial condyle decreased compared with that of the lateral condyle after overcorrection of varus deformity. In the cases of more than 7 years after high tibial osteotomy, a positive straight regression line was drawn by calculation between Medial/Lateral ratio and postoperative limb alignment expressed by standing femorotibial angle, with coefficient of correlation (gamma) of 0.295 (p < 0.01).  (+info)