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At least 19 recordsLinked to original sources
PubMed2006

A vascularized technique for bone-tissue-bone repair in scapholunate dissociation.

Several surgical options have been used for the repair of scapholunate instability over the last 50 years. The many options have included neglect, reduction with percutaneous pinning, primary repair, partial fusions, tendon weaves, and others. Recent advancements in scapholunate repair and anatomy have been aimed at a more physiological repair. Composite replacement of the entire scapholunate interval similar to other tendon repairs seen in orthopedic surgery has become popular. Currently, more common hand-based grafts are bone-retinaculum-bone, third or second metacarpal-carpal bone or hamate-capitate grafts. There still exist some failures in the outcome after any of these procedures. This technique demonstrates the use of a vascularized autograft replacement on a pedicled graft. This procedure is the natural extension of the third or second metacarpal-carpal bone autograft, previously reported in the literature. The use of this proven graft, with a pedicle based on the intermetacarpal artery, may avoid some of the late complications seen with other autografts.

Bone Transplantation↗
PubMed2000

Effect of embryonic bone tissue on bone regeneration.

Fragmented embryonic bone tissue stimulates bone regeneration. Bone formation starts not from implanted embryonic fragments, but in intact periosteum and endosteum containing cambial cells of the osteodifferon. In rabbits, recovery of damaged radial bone after implantation of fragmented embryonic bone tissue into bone defect was associated with a pronounced periosteal reaction and focal resorption of intact ulnar bone. Consolidation of damaged radial bone without implantation of fragmented embryonic bone tissue was incomplete in all experimental animals.

Animals↗
PubMed1990

[Explanation of nonspecific serologic reactions in decomposed bone tissue].

Bone fragments were stored in water for 2 years at room temperature and investigated serologically using the following methods: Absorption-elution, extraction of blood group substances and immunohistochemistry (PAP). All 3 methods gave essentially specific results for fresh bone tissue but with putrid bone tissue unspecific reactions were found predominantly with the absorption-elution and PAP techniques. In contrast, more specific reactions were obtained from the extracts although they were much weaker. From this it can be concluded that pure physical binding plays a substantial role in the unspecific reaction between antibodies and bone material. It is suggested that the relevant physical properties are altered by putrification.

ABO Blood-Group System↗
PubMed2006

Physiological bases of bone regeneration I. Histology and physiology of bone tissue.

Bone is the only body tissue capable of regeneration, allowing the restitutio ad integrum following trauma. In the event of a fracture or bone graft, new bone is formed, which following the remodeling process is identical to the pre-existing. Bone is a dynamic tissue in constant formation and resorption. This balanced phenomena, known as the remodeling process, allows the renovation of 5-15% of the total bone mass per year under normal conditions. Bone remodeling consists of the resorption of a certain amount of bone by osteoclasts, likewise the formation of osteoid matrix by osteoblasts, and its subsequent mineralization. This phenomenon occurs in small areas of the cortical bone or the trabecular surface, called Basic Multicellular Units (BMU). Treatment in Traumatology, Orthopedics, Implantology, and Maxillofacial and Oral Surgery, is based on the biologic principals of bone regeneration, in which cells, extracellular matrix, and osteoinductive signals are involved. The aim of this paper is to provide an up date on current knowledge on the biochemical and physiological mechanisms of bone regeneration, paying particular attention to the role played by the cells and proteins of the bone matrix.

Bone Matrix↗
PubMed2003

[Cells of bone tissues].

Bone cells consist of osteoblasts, osteocytes, and osteoclasts. Osteoblasts secrete collagen and orientate directions of collagen fibrils to form bone lamellae in the bone matrix. Osteocytes are differentiated in the layer of osteoblasts as functionally different cells from the osteoblasts and sink into the bone matrix to form a network of cell processes to monitor the stress added to the bone. Osteoclasts, multinuclear giant cells on the bone, resorb the bone matrix on the bone surface. These three kinds of bone cells functionally cooperate to each others.

English Abstract↗
PubMed1983

[The rate of linear deposition of bone tissue in the bone spongiosum of lactating rats on a low calcium diet].

In the epiphysis and metaphysis of lactating rats, submitted to a Ca++ depletion for 10 and 30 days and a Ca++ repletion diet for 10 days, the density of spongiosa framework and the bone tissue linear accretion rate were compared with those of control rats. The distal metaphyses of femora of the rats fed a calcium free diet for 10 and 30 days lose 50% and 90% of the trabecular framework respectively, while the epiphysis of the same bone lose only 45% and 56%. The linear accretion rate in these regions increases by 7.9 and 24.7% in the epiphysis and by 11.3% and 75.6% in the metaphysis of rats fed a calcium-free diet for 10 and 30 days respectively. Our data indicate that the bone tissue linear accretion rate changes not only between the corresponding regions of control and experimental rats but, in the latter, also in different regions of the same bone. Moreover, the higher the bone loss is, the higher bone accretion rate will be. The correlation between the bone tissue linear accretion rate and the bone loss indicates that the same local factor - probably mechanical - controls the activity and distribution of osteoblasts and osteoclasts.

Animals↗
PubMed1992

The histopathology of different foreign-body reactions in oral soft tissue and bone tissue.

Foreign bodies may be endogenous or exogenous and provoke chronic inflammation of the foreign-body type. The reaction provides a mechanism for elimination of the foreign body and the reaction pattern depends on the kind of tissue involved. In soft tissues there is cellular inflammation and fibrous encapsulation with macrophages. In bone, during the healing period, biomechanical factors determine whether a fibrous encapsulation or a bony covering develops demarcating the foreign material. The particular characteristics of the foreign-body reaction in bone explain the success of dental and orthopaedic implants.

Animals↗
PubMed1992

Microscopy of bone cells, bone tissue, and bone healing around implants.

Newer methods of scanning microscopy using both light and electrons are particularly relevant to the study of bone cells, bone matrix organization, matrix mineralization, bone modeling and remodeling, and the adaptation of cells and matrix to implants. Most of such studies are conducted on retrieved implants, at least after the death of the related tissue. Because the retention of the tissue-implant relationship in such preserved tissue is crucial for critical evaluation of the implant, methods based on the study of flat surfaces of embedded tissue blocks are very important. Using electrons, the backscattered electrons in a scanning electron microscope can be employed to evaluate mean atomic number (density) and cathodoluminescence can identify polymers and fluorescent labels. Using light, confocal microscopical techniques permit the examination of layers deep to the block face. Confocal reflected and fluorescence methods allow the study of cell behavior upon both transparent and opaque substrates in the laboratory. Examples of the above are presented and interpretation problems discussed. Current experiments are aimed at enabling the study of bone wound healing and bone adaptation to implanted materials in vivo, through the implantation of optical quality windows and/or newly conceived and designed microscopical objective lenses.

Animals↗
PubMed2003

Effect of lacunocanalicular architecture on hydraulic conductance in bone tissue: implications for bone health and evolution.

Bone tissue health depends largely on efficient fluid and solute transport between the blood supply and cells that are the living component of the tissue. We hypothesized that the lacunocanalicular hydraulic network, which is defined by the pericellular fluid space that is common to all bone tissue, is optimized to transport fluid and solutes between the blood supply and bone cells. An analytical study was carried out to evaluate the effect of osteonal architecture, including the osteon diameter, number of annular lamellar regions, and number and length of canalicular channels, on fluid transport between the blood supply and bone cells. On the basis of this analysis, we conclude that osteon size is limited to the distance over which fluid and solutes can be transported efficiently between the blood supply and cells. This analytic model suggests that hydraulic conductivity is highest in lamellar regions closest to the Haversian canal (HC) and decreases with increasing distance from the blood supply, reaching a plateau after the fifth lamella (169 micro m radius). Furthermore, an increase in the diameter of the HC, or a decrease in the length of canaliculi, reduces the hydraulic conductivity within the lacunocanalicular network. Applying the principle of minimal expenditure of energy to this analysis, the path distance comprising five or six lamellar regions represents an effective limit for fluid and solute transport between the blood supply and cells; beyond this threshold, hydraulic resistance in the network increases and additional energy expenditure is necessary for further transportation. This suggests that transport is optimized to meet metabolic demands concomitant with a minimal expenditure of energy. This fundamental new insight into bone structure and physiology may provide a new basis of understanding for tissue engineering, bone physiology in health and disease, and evolutionary biology.

Animals↗
PubMed1988

Production of hemopoietic growth factors by bone tissue and bone cells in culture.

This study was carried out to determine whether bone might be a source of hemopoietic growth factors. Both neonatal murine calvaria and primary cultures of cells isolated from calvaria released, upon stimulation with lipopolysaccharide, an activity that stimulated the growth of the interleukin (IL) 3-dependent cell lines, 32D cl, 123, and NSF 60. Upon gel filtration, this activity eluted with a molecular weight of 30,000 kDa. Further characterization, however, revealed that the major activity in conditioned medium was not IL 3. Activity was absorbed by DEAE-Sephacel at low salt concentration, whereas IL 3 does not adhere. Furthermore, an IL 3-specific antiserum did not neutralize the activity from cells and only partly neutralized the activity generated by whole calvaria. After gel filtration, the 30-kDa activity stimulated the growth of very large colonies in semisolid medium consisting mainly of granulocytes with the remainder being macrophages. No colony types belonging to other hemopoietic lineages were found, indicating, again, that the activity was not identical to IL 3. Subsequently, conditioned medium was fractionated by hydrophobic chromatography on Phenyl-Sepharose CL-4B, yielding two peaks of activity. Neutralization of activity with antisera to granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL 3 and use of colony assays showed that medium conditioned by whole calvaria contained GM-CSF and granulocyte CSF (G-CSF) in similar amounts together with a little IL 3, and medium conditioned with calvaria cells contained GM-CSF and little G-CSF. We conclude that bone releases hemopoietic growth factors that could contribute both to hemopoiesis and to the recruitment of osteoclasts from progenitors resident in the adjacent marrow.

Animals↗
PubMed1987

Fatty acid oxidation in bone tissue and bone cells in culture. Characterization and hormonal influences.

Fatty acid oxidation and its hormonal modulation were investigated in cultured rat calvaria and in cultivated cell populations. The latter were obtained from calvaria of newborn rats by sequential time-dependent digestion with collagenase, yielding eight cell populations: the early ones containing mainly fibroblasts, the middle ones being osteoblast-like, and late ones osteoblast-osteocyte-like. In calvaria, fatty acid oxidation was increased by adding 0.1 mM- and 1.0 mM-palmitate to the medium, containing 10% (v/v) fetal-calf serum. No effect was found after parathyrin addition in vitro or when injected in vivo. All cell populations obtained by sequential digestion were found to oxidize palmitate, whereby the osteoblast-like cells showed a lower oxidation rate than the other populations. Both parathyrin and calcitonin had no effect on fatty acid oxidation. 1,25-Dihydroxycholecalciferol at 1-100 nM and 24,25-dihydroxycholecalciferol at 100 nM increased oxidation primarily in the population enriched with osteoblast-like cells. Insulin at 1.6 microM diminished it in the cell populations enriched with osteoblast-like cells and in the late bone-cell fraction. However, glucagon had no effect. The energy provided by fatty acid oxidation in this system is approx. 40-80% of glucose metabolism, suggesting that this event may be of importance in the energy metabolism of bone.

Adenosine Triphosphate↗
PubMed1994

[Course of bone tissue after bone marrow allograft in adolescents with sickle cell disease].

PURPOSE OF THE STUDY: Allogenic B.M.T. has been investigated as a curative treatment of anemia in S.C.D. Furthermore, correction of functional asplenia has been observed after B.M.T.; it remains to be determined if such a treatment may reserve other organ damage and particularly bone abnormalities and osteonecrosis frequently associated with S.C. hemoglobinopathies. MATERIAL AND METHODS: The aim of this retrospective review was to evaluate the radiologic and MRI results of 2 patients with avascular necrosis before the B.M.T. Roentgenographic diagnosis of osteonecrosis before B.M.T. included, for the 2 patients, depression and fragmentation of the articular surface. MRI imaging of the bones of these patients observed before B.M.T. a decreased signal intensity relative to subcutaneous fat on the short TR/TE images instead of the high signal intensity of the usual fatty marrow in epiphysis. RESULTS: Only three months after the B.M.T., osteonecrosis appeared to have healed without deformity for the two patients. Furthermore, MRI imaging of the bones at three months after B.M.T. observed a high signal intensity in the epiphysis corresponding to a yellow marrow. DISCUSSION: Because of the stress on the marrow system in children with severe chronic hemolytic anemia, red marrow remains hyperplastic and extensive throughout the body and normal red marrow conversion to fat marrow is postponed in S.C.D.; marrow infarction in S.C.D. develops in red marrow; since red marrow persists in the epiphysis in S.C.D., these patients have these sites for potential infarction. Our observation shows MRI changes in the epiphysis and diaphysis marrow after B.M.T.; the appearance of the marrow changes after transplantation in these patients may reflect hemodynamic and physiologic phenomena attributable to the combined effects of the pretransplant chemotherapy and new bone marrow reconstitution after transplantation. This tendency of normalization of the epiphysis with red-yellow marrow conversion after B.M.T. is important since it is a reduction of the potential sites for infarction. This red-yellow marrow conversion after B.M.T. may also explain the velocity of the reconstruction of the epiphysis after osteonecrosis; if osteonecrosis may heal without deformity in the prepubertal epiphysis of children, it takes usually 5 or 6 years and this phenomena is very uncommon; healing was here observed only 3 weeks after B.M.T.; the effect of the B.M.T. on the reconstruction of the epiphysis may be explained by the following hypothesis: hematopoietic marrow of the epiphysis in S.C.D. had a rich sinusoidal system fed by several epiphyseal vessels; blood flow in the sinusoidal system is sluggish and the biochemical environment in this area facilitates the sickling process; blood containing sickled cells had high viscosity and produces a relative obstruction to blood flow in the sinusoidal system of the epiphysis. When sickled red cells are replaced with normal cells after B.M.T., bone circulation in the epiphysis is restored and allowed quick reconstruction when osteonecrosis is present. CONCLUSION: This study seems to demonstrate that bone abnormalities associated with S.C.D. are reversible after B.M.T., phenomena of critical importance to support the eventual role B.M.T. as a curative treatment in S.C.D.

Adolescent↗