Publications (6)42.3 Total impact
-
Article: Phenotypic diversity in chondromyxoid fibroma reveals differentiation pattern of tumor mimicking fetal cartilage canals development: an immunohistochemical study.
[show abstract] [hide abstract]
ABSTRACT: Chondromyxoid fibroma represents a rare benign cartilaginous tumor of young patients occurring in a subcortical metaphyseal location. The histogenesis of chondromyxoid fibroma has not yet been postulated, even though the conventional histology and recent immunohistochemical studies on phenotype of the mesenchymal cells and extracellular matrix components suggested its origin in immature cartilage. Therefore, we wished to compare the morphological pattern of immature cartilage tissue with chondromyxoid fibroma to investigate a possible developmental counterpart of chondromyxoid fibroma. Archival paraffin-embedded tissues from 4 fetal femora and 10 cases of chondromyxoid fibroma were analyzed simultaneously using histochemistry (safranin O) and established immunohistochemical antibodies (CD34, CD163, and smooth muscle actin). Vascularized cartilage canals growing into the fetal cartilage from the perichondrium displayed characteristic glomeruloid structures with central arterioles within the immature mesenchymal stroma and numerous superficial sinusoidal blood vessels accompanied by macrophage infiltration. Similarly, each case of chondromyxoid fibroma demonstrated admixture of two characteristic components: immature fibrous tissue of vascularized stroma with accumulation of macrophages in areas of superficial sinusoidal proliferation, and variable amounts of lobulated chondroid tissue. Based on the observed substantial morphological similarity between the cartilage canals and chondromyxoid fibroma, we suggest that the chondromyxoid fibroma represents a neoplasm originating from or mimicking the fetal cartilage canals within the immature cartilage.American Journal Of Pathology 09/2010; 177(3):1072-8. · 4.89 Impact Factor -
Article: Microarchitecture of the radial head and its changes in aging.
[show abstract] [hide abstract]
ABSTRACT: Fractures of the radial head are common; however, it remains to be determined whether the radial head has to be considered as a typical location for fractures associated with osteoporosis. To investigate whether the human radial head shows structural changes during aging, we analyzed 30 left and 30 right human radial heads taken from 30 individuals. The specimens taken from the left side were analyzed by peripheral quantitative computed tomography (pQCT) and micro-CT. The specimens taken from the right elbow joint were analyzed by radiography and histomorphometry. In these specimens pQCT revealed a significant decrease of total and cortical bone mineral density (BMD(to) BMD(co)) with aging, regardless of sex. Histomorphometry revealed a significant reduction of cortical thickness (Ct.Th), bone volume per tissue volume (BV/TV), and trabecular thickness (Tb.Th) in male and female specimens. In this context, mean BV/TV and mean trabecular number (Tb.N) values were significantly lower and, accordingly, mean trabecular separation (Tb.Sp) was significantly higher in female samples. The presented study demonstrates that the radial head is a skeletal site where different age- and sex-related changes of the bone structure become manifest. These microarchitectural changes might contribute to the pathogenesis of radial head fractures, especially in aged female patients where trabecular parameters (BMD(tr) and Tb.Sp) change significantly for the worse compared to male patients.Calcified Tissue International 11/2009; 86(1):14-22. · 2.38 Impact Factor -
Article: Age- and sex-related changes of humeral head microarchitecture: histomorphometric analysis of 60 human specimens.
[show abstract] [hide abstract]
ABSTRACT: Fractures of the humeral head are frequent and will further increase due to demographic changes. Prior to operative fracture treatment, the regional differences of bone quality, especially of elderly people, have to be carefully considered to assure stable implant fixation. However, conclusive data concerning the variation of histomorphometric parameters are still lacking. Consequently, the purpose of this study was to analyze the age- and sex-related changes in bone microarchitecture. For that reason, 60 proximal humeri were harvested from patients at autopsy. Twelve regions of interest (ROI) were defined for each centered coronar humeral head slice and the specimens were subjected to radiographic, histological, and histomorphometric analyses. We could demonstrate that in contrast to men, women over 60 years of age had a significant age-related decrease in bone mass. The most prominent decrease was observed in the region of the greater tuberosity, which represents an osteoporotic fracture site. The most superior and medially located part of the centered coronar humeral head slice showed, independent from age and sex, the highest bone mass and can therefore be considered as the best location for subchondral screw placement. Taken together, our study revealed distinct sex-related changes of the humeral head bone microarchitecture with aging, which should be considered in implant positioning.Journal of Orthopaedic Research 08/2009; 28(1):18-26. · 2.81 Impact Factor -
Article: Impaired gastric acidification negatively affects calcium homeostasis and bone mass.
[show abstract] [hide abstract]
ABSTRACT: Activation of osteoclasts and their acidification-dependent resorption of bone is thought to maintain proper serum calcium levels. Here we show that osteoclast dysfunction alone does not generally affect calcium homeostasis. Indeed, mice deficient in Src, encoding a tyrosine kinase critical for osteoclast activity, show signs of osteopetrosis, but without hypocalcemia or defects in bone mineralization. Mice deficient in Cckbr, encoding a gastrin receptor that affects acid secretion by parietal cells, have the expected defects in gastric acidification but also secondary hyperparathyroidism and osteoporosis and modest hypocalcemia. These results suggest that alterations in calcium homeostasis can be driven by defects in gastric acidification, especially given that calcium gluconate supplementation fully rescues the phenotype of the Cckbr-mutant mice. Finally, mice deficient in Tcirg1, encoding a subunit of the vacuolar proton pump specifically expressed in both osteoclasts and parietal cells, show hypocalcemia and osteopetrorickets. Although neither Src- nor Cckbr-deficient mice have this latter phenotype, the combined deficiency of both genes results in osteopetrorickets. Thus, we find that osteopetrosis and osteopetrorickets are distinct phenotypes, depending on the site or sites of defective acidification.Nature medicine 06/2009; 15(6):674-81. · 27.14 Impact Factor -
Article: Brief communication: Two and three-dimensional analysis of bone mass and microstructure in a bog body from the Iron Age.
[show abstract] [hide abstract]
ABSTRACT: Human remains from peat bogs, called "bog bodies," have yielded valuable insights into human history because of their excellent preservation of soft tissue. On the other hand, the acidic environment of the peat leads to an extensive demineralization of skeletal elements, complicating their analysis. We studied the skeleton of the bog body "Moora" dated to approximately 650 B.C. Nondestructive evaluation of the bone was made using contact X-rays, peripheral quantitative computed tomography (pQCT) analysis, multislice computed tomography (CT) and high resolution micro computed tomography (microCT) imaging. Two thousand seven hundred years in the acidic environment of the bog led to a loss of 92.7% of bone mineral density. Despite this demineralization and in contrast to other bog bodies, the spatial structure of the bones of "Moora" is exceptionally well preserved. We found Harris lines and were able to obtain the first three-dimensional data on the trabecular microstructure of the bone of a young woman from the early Iron Age.American Journal of Physical Anthropology 05/2008; 135(4):479-83. · 2.82 Impact Factor -
Article: A scanning electron microscopy-based approach to quantify resorption lacunae applied to the trabecular bone of the femoral head.
[show abstract] [hide abstract]
ABSTRACT: Resorption lacunae (RL) are discussed as stressors that can increase the risk of mechanical failure in a trabecular network. Quantification of RL has previously been described through the parameter eroded surface/bone surface (ES/BS) as established by light microscopy (LM) analysis, but the results have been inconsistent and contradictory. Using scanning electron microscopy (SEM), a new study design for quantitative evaluation is introduced. To test its applicability a pilot study was executed with trabecular bone dissected from a femoral head of 28 autopsy subjects (14 female and 14 male). A 2.4 x 2.8 x 1.0 mm sample was excised 1.5 cm below the joint surface of each specimen in coronal medial slices of the femoral head and examined. A virtual grid with 1050 squares superimposed over the generated SEM image allowed determination of the ratio of squares containing RL to squares with an unaffected trabecular surface (RL/U). Classical ES/BS was assessed in parallel sections of the samples. The SEM, and to a lesser extent the qualitative different LM analysis, indicated a gender independent predominance of RL in subjects older than 50 years. This pilot study suggests that the new study design could be useful for acquiring quantitative RL data.Journal of Bone and Mineral Metabolism 02/2005; 23(3):205-11. · 2.27 Impact Factor
Top co-authors
Top Journals
Institutions
-
2009
-
University Medical Center Hamburg - Eppendorf
Hamburg, Hamburg, Germany
-
-
2008–2009
-
Universität Hamburg
- Department of Trauma-, Hand- and Reconstructive Surgery
Hamburg, Hamburg, Germany
-
