Bone Abstracts

Background and methods: Pigment epithelium-derived factor (PEDF) is a potent antiangiogenic factor, ubiquitously expressed and secreted in human tissues. Hypertrophic cartilage and osteoblasts express PEDF that binds to type I collagen and glycosaminoglycans in the extracellular matrix. Two rare forms of osteogenesis imperfecta (OI) with intact collagen synthesis are associated with PEDF deficiency. Histological observations revealed excessive osteoid formation and prolonged m...

Mutations in the C-propeptide cleavage site of both COL1A1 and COL1A2 cause dominant high bone mass (HBM) osteogenesis imperfecta (OI), characterized by bone hypermineralization. To elucidate the role of C-propeptide processing in bone formation, we generated heterozygous HBM mice in which both residues of the COL1A1 cleavage site were mutated to prevent cleavage by BMP1. HBM mice are smaller than WT in both weight and length and have extremely brittle bones....

High Bone Mass (HBM) osteogenesis imperfecta (OI) is caused by dominant mutations in the C-propeptide cleavage site of COL1A1 or COL1A2, characterized by bone hypermineralization. To elucidate the role of C-propeptide processing in bone mineralization and development, we generated heterozygous HBM mice with both residues (Ala-Asp) of the COL1A1 cleavage site substituted (Thr-Asn) to prevent processing by BMP1. Two, 6- and 12-month WT and HBM bones were examin...

Background: Congenital multiple hormone deficiency (CMHD) is a rare condition caused by mutations in transcription factors involved in pituitary ontogenesis1. Incidence of mutations in POU1F1 gene in results between 3.8 and 7.7%2. POU1F1 gene mutations lead to somatolactotroph and thryotroph deficiencies. Brain MRI can be normal or shows pituitary hypoplasia without extrapituitary anomalies.Presenting problem: We describe the growth...

Background: Weyers acrofacial dysostosis (WAD, OMIM 193530) is a rare autosomal dominant disease, characterized by mildly short stature, postaxial polydactyly, nail dystrophy and dental anomalies. WAD should be distinguished from Ellis-van Creveld syndrome (OMIM 225500), a similar but more severe disease, comprising chondrodysplasia, orofacial anomalies and, in a proportion of patients, cardiovascular malformations. Both diseases are caused by mutations in either EVC or EVC2<s...

Chondrosarcomas are cartilage-forming, poorly vascularized tumors. With an estimated annual incidence of 1 in 200 000, they represent the second malignant primary bone tumor of adults after osteosarcoma. These tumors are resistant to chemotherapy and radiotherapy, surgical excision remaining the only therapeutic option. However, very few cell lines and animal models are available, and the mechanisms behind their chemoresistance remain largely unknown. Our goal was to establish...

Osteogenesis imperfecta (OI) is a heritable bone dysplasia with collagen-related defects. Dominantly inherited OI is caused by structural defects in type I collagen or IFITM5, while recessive forms are caused by deficiency of proteins that interact with collagen for modification, folding or cross-linking. We have identified the first X-linked form of OI, caused by a defect in regulated intramembrane proteolysis (RIP). One type of RIP involves sequential cleavage of regulatory ...

Objectives: The aim of the study was to establish features of macroelemental composition of the dentin in mature male rat’s mandibular incisors with biogenic hydroxyapatite, implanted in the proximal part of tibial shaft.Material and methods: One hundred and twenty-six mature male rats were divided into three groups: 1st group – intact animals, 2nd group – animals with the pit defect applied on the proximal part of tibial shaft (systematic...

Background: Stuve–Wiedemann syndrome (SWS, OMIM 601559) is a severe autosomal recessive condition characterized by bowing of the lower limbs with cortical thickening, wide metaphyses, abnormal trabecular pattern and camptodactyly. Additional features include dysautonomia symptoms with temperature instability, respiratory distress and sucking/swallowing difficulties in the first months of life.Most SWS cases do not survive beyond the first y...

Rheumatoid arthritis (RA) is marked by the persistent inflammation and osteodestruction, causing progressive disability. Osteoclast progenitors (OCPs) represent a subpopulation of peripheral blood monocytes and have been shown to be present in healthy subjects and arthritic patients. The aim of our study was to determine the phenotype, frequency and osteoclastogenic potential of OCPs in the peripheral blood and synovial fluid of RA patients in response to anti-TNF therapy....