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Effect of Gusuibu graft on bone formation.

PURPOSE: We compared the amount of new bone produced by Gusuibu in collagen grafts to that produced by bone grafts and collagen grafts. MATERIALS AND METHODS: Twenty bone defects were created in the parietal bone of 14 New Zealand White rabbits. In the experimental group, 5 defects were grafted with Gusuibu extract mixed with absorbable collagen sponge, and 5 defects were grafted with autogenous endochondral bone. In the control groups, 5 defects were grafted with absorbable collagen sponge alone (active control) and 5 were left empty (passive control). Animals were killed on day 14 and the defects were dissected and prepared for histologic assessment. Serial sections were cut across each defect. Quantitative analysis of new bone formation was made on 150 sections using image analysis. RESULTS: A total of 24% and 90% more new bone were present in defects grafted with Gusuibu in collagen grafts than those grafted with bone and collagen, respectively. No bone was formed in the passive control group. CONCLUSIONS: Gusuibu in collagen grafts have the effect of increased new bone formation locally and can be used as a bone graft material.

Absorbable Implants↗

Integrin subunit beta3 plays a crucial role in the movement of osteoclasts from the periosteum to the bone surface.

We have shown that, when mouse parietal bones were incubated in culture medium containing indomethacin, the number of tartrate-resistant acid phosphatase-positive osteoclasts (TRAP + OCs) on the bone surface was drastically reduced (down-regulation), and the number on the periosteal membrane adjacent to the resorbing surface was increased. Subsequent incubation of bones with prostaglandin E2 (PGE2) rapidly reversed these changes (up-regulation). In the work reported here, the osteoclast-associated integrin subunit beta3 was stained by immunohistochemistry. The beta3-positive osteoclast (beta3 + OC) population on freshly isolated bone was comprised of about 67% TRAP + OCs and 33% TRAP OCs. Like TRAP + OCs, beta3 + OCs were reduced in number on the surface of bones incubated with indomethacin, but, in contrast to the TRAP + OCs, beta3 + OCs were not seen on the periosteal membrane. Following up-regulation of TRAP + OCs with PGE2, large numbers of beta3 + OCs appeared on the bone surface and, again, were not seen on the periosteal membrane. Echistatin, a peptide that binds to the alphavbeta3 integrin on osteoclasts, was found to inhibit the up-regulation of TRAP + OCs in a dose-dependent manner but had no effect on the down-regulation of TRAP + OCs. Similarly, echistatin inhibited the upregulation of beta3 + OCs on the bone surface, and, under these conditions, beta3 + OCs were observed on the periosteal membrane. The addition of anti-beta3 antibody also inhibited the up-regulation of TRAP + OCs in response to PGE2. The association of beta3 protein expression with the up-regulated osteoclast and the inhibition of up-regulation by echistatin and by anti-beta3 antibody provide strong evidence that beta3 plays an essential role in the movement of osteoclasts from the membrane to the bone.

Acid Phosphatase↗

Cranial bone grafting in children.

Computed tomographic scans of 96 patients from newborn to 21 years of age were reviewed to assess the thickness of the skull and diploic space. Cranial thickness of the parietal bone used for calvarial bone harvest was assessed. Analysis of the data revealed that (1) cranial bone thickness may be predicted reliably as a function of age, (2) the growth velocity of increasing thickness of the parietal bone decreased with increasing age, and (3) presence of a diploic space may be predicted reliably as a function of age. On the basis of this analysis, we recommend performing split cranial bone grafting after the age of 3 years. In situ cranial bone grafting should not be planned prior to the age of 9 years.

Age Factors↗

Morphogenetic potential of rat growth cartilages as isogeneic transplants in the interparietal suture area.

The proximal end of the tibia or the spheno-occipital synchondrosis with some adjoining bone were isogeneically transplanted across the interparietal suture of 10-day-old rats. As a sham procedure, a piece of calvarium traversed by a part of the interparietal suture was interchanged between pairs of animals. Untreated rats served as controls. The animals, injected with Alizarin red S, were killed 25-75 days after the operation, 10 in each group. The transverse dimensions of the neurocranium were larger in the rats with the cartilage transplants than in the controls, particularly at 25 days after the operation; the differences persisted longer in the animals with the synchondroseal transplant. The orientation of the bone interdigitation at the anterior lambdoidal suture changed temporarily in response to the excessive lateral displacement of the parietal bones. The observations indicate that basicranial synchondroses, like epiphyseal cartilage, are endowed with a tissue-separating property that may persist for a prolonged period under transplant conditions. As such cartilaginous structures may also be affected by environmental influences, there must be a two-way interaction between the synchondroses and their immediate environment.

Animals↗

An autopsy case of traumatic sinus thrombosis.

A 38-year-old male slipped accidentally and fell from a height of 4.6 m, and was admitted to a hospital. A radiograph indicated a linear fracture of the parietal bone across the sagittal sutura, and a computed tomography scan of the head showed severe subdural hematoma on both parietal sides, so an operation was performed to remove the hematoma. Five hours after the operation, brain death due to a cerebral herniation occurred, and he died six days later. Autopsy revealed a linear fracture of the parietal bones, which crossed obliquely the sagittal sutura. A slightly lacerated wound of the dura mater was seen on the sagittal sutura, from where the latter half of that point to the left and right transverse sinuses were occluded completely with thrombosis. The brain was markedly swollen. From these findings, the victim was considered to have died from acute cerebral swelling due to traumatic thrombosis of the superior sagittal sinus.

Adult↗

Studies on orthocephalization. VII. Behavior of the rat cranial frame in the period between 1 day before birth to 14 days after birth.

The positional stability of the zygomatic arch of the rat skull in relation to the parietal bone, the basisphenoid bone and the length axis of the skull, as previously demonstrated in rats older than 14 days, does not exist to the same degree in younger rats. These conclusions have been drawn from a study of a sample of rats, aged 0, 4, 7 and 14 days. These 4 groups of rats have been x-rayed after sacrifice, and from the x-ray photographs, quantitative expressions of angular values between the mentioned structures have been obtained. The most important result is, however, considered to be, that a full description of the behavior of the external cranial frame of the rat skull is now available for further studies on the process of orthocephalization.

Aging↗

Evidence that IGF-binding protein-5 functions as a growth factor.

Recent studies support the concept that IGF-binding protein-5 (IGFBP-5) stimulates bone formation, at least in part, via IGF-independent mechanisms. To evaluate this hypothesis further, we evaluated in vitro and in vivo effects of IGFBP-5 on bone formation parameters using the IGF-I knockout (KO) mouse. Treatment of serum-free cultures of osteoblast clones derived from IGF-I KO mice with recombinant human IGFBP-5 increased both proliferation and alkaline phosphatase (ALP) activity in a dose-dependent manner, an effect comparable to that seen with IGF-I. IGF-II levels from media conditioned by osteoblasts derived from IGF-I KO mouse were below those detectable by RIA. To eliminate possible actions of IGF-II, if any was produced by osteoblasts derived from IGF-I knockout mice, the IGFBP-5 effect was studied in the presence of exogenously added IGFBP-4, a potent inhibitor of IGF-II actions in bone cells. Addition of IGFBP-4 blocked IGF-I- but not IGFBP-5-induced cell proliferation in osteoblasts derived from IGF-I knockout mice. Consistent with in vitro results, a single local injection of IGFBP-5 to the outer periosteum of the parietal bone of IGF-I KO mice increased ALP activity and osteocalcin levels of calvarial bone extracts. The magnitudes of IGFBP-5-induced increases in ALP and osteocalcin in parietal bone extracts of IGF-I KO mice were comparable to those seen in C3H mice. In contrast to IGFBP-5, local administration of IGFBP-4 had no significant effect on bone formation in C3H and IGF-I KO mice. These results provide the first direct evidence to our knowledge that IGFBP-5 functions as a growth factor that stimulates its actions in part via an IGF-independent mechanism.

Alkaline Phosphatase↗

Insulin-deficient diabetes impairs osteoblast and periodontal ligament fibroblast metabolism but does not affect ameloblasts and odontoblasts: response to tetracycline(s) administration.

Insulin-deficient, adult, diabetic rats were administrated a tetracycline (either minocycline or a chemically-modified non-antimicrobial tetracycline: CMT) by oral gavage over a 3-week period. Untreated diabetic and non-diabetic rats served as controls. On day 21, all rats received an intravenous injection of 3H-proline, as a radioprecursor of procollagen in bone, dentine and periodontal ligament (PDL) or of amelogenin in enamel; perfusion fixation with an aldehyde mixture was carried out at 20 minutes and 4 hours after isotope injection. The parietal bones (calvaria), mandibules including molars, and lower incisors of these rats were dissected and processed for light microscopic autoradiography to study 3H-proline utilization by osteoblasts, PDL fibroblasts, odontoblasts and ameloblasts. In the control rats, at 20 minutes after 3H-proline injection, silver grains of labeled precursor were detected in the osteoblasts of the periosteal surfaces of the parietal bones. At the 4 hour time period, although some radioprecursor was still present in the osteoblasts, most had progressed to the osteoid matrix. In contrast, the flattened bone-lining cells in the untreated diabetics showed minimal uptake and secretion of labeled proline at both time periods. In both minocycline- and CMT-treated diabetic rats, the labeled proline was localized in the osteoblasts and the osteoid in a pattern reminiscent of that seen in the control rats at both time periods. Of interest, CMT administration appeared to increase the labeling of the osteoid matrix more than minocycline treatment. In non-diabetic control rats, the PDL fibroblasts exhibited a polarized elongated profile and incorporated and secreted radioprecursor similar to that described for the osteoblasts in these animals. The PDL fibroblasts in the untreated diabetics lost their regular arrangement and incorporated little if any 3H-proline; once again, tetracycline administration appeared to normalize, at least in part, the structure and 3H-proline incorporation by these connective tissue cells. In contrast, diabetes and tetracycline administration did not affect the incorporation and secretion of radioprecursor by odontoblasts and secretory ameloblasts during tooth development.

Ameloblasts↗

Stimulation of bone formation in vivo by transforming growth factor-beta: remodeling of woven bone and lack of inhibition by indomethacin.

Local effects of transforming growth factor-beta (TGF beta) on bone have been investigated in growing mice. The influence of indomethacin on TGF beta effects was also examined. Five daily injections of TGF beta-1 or -2 were administered subcutaneously over the frontal and parietal bones of seven-week-old mice. In animals treated with TGF beta alone or TGF beta and indomethacin, then killed on day 19 (day 1 = day of first TGF beta injection), the combined frontal and parietal bones were heavier and the frontal bones were thicker than in controls. On day 4, multiple layers of differentiating osteoblasts were visible in the periosteum of calvariae from TGF beta-treated animals. On day 8, highly vascularised periosteal woven bone was seen in the calvariae of TGF beta-treated animals. On day 19 (14 days after the last injection) the woven bone had been partially remodeled into lamellar bone containing bone marrow, and was still actively being remodeled. The histological appearance of bones from animals treated concurrently with TGF beta and indomethacin was identical to that of animals treated with TGF beta alone, and there appeared to be no difference between TGF beta-1 and TGF beta-2. Thus TGF beta-stimulated bone formation in vivo is a long term effect that appears to be independent of prostaglandins. Osteoclast counts in sections of TGF beta-treated animals were not elevated on day 4, although at this stage effects on osteoblastic cells were already morphologically apparent. Osteoclast counts in TGF beta-treated bones were significantly increased over control values on days 8 and 19.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Multiple growths of primary calvarial meningiomas.

The authors present the case of a 68-year-old woman with multiple growths of primary calvarial meningiomas. Histological examination revealed one tumor arising in the left parietal bone that showed some malignant aspects, including hypercellularity, cellular pleomorphism, necrotic foci, and some mitoses; the tumor partially had a meningotheliomatous pattern. Two other tumors in the right parietal bone were meningotheliomatous meningiomas without any malignant features. With a review of the literature, the pathogenesis of the multiplicity is discussed.

Aged↗

Reduced life span of the osteoclast in osteopetrotic (mi and midi) mice.

Osteoclasts were enumerated on the parietal bones of mice carrying combinations of alleles (mi, midi and +) at the microphthalmic locus. Homozygous mutants at this locus show varying degrees of osteopetrosis due to defective bone resorption. As the severity of the bone resorption defect increased across the genotypes, there was an increase in the total number of osteoclasts and also an increase in the proportion of uninucleate osteoclasts. In parietal bones incubated for 24 h with parathyroid hormone (PTH) there was no significant difference between osteopetrotic and normal bones in terms of the number of osteoclast nuclei that had taken part in fusion. When bones were incubated for 24 h in the absence of PTH the percentage of osteoclasts remaining was correlated inversely with the severity of the bone resorption defect. Thus, we suggest that the increased proportion of uninucleate osteoclasts in these mutants results from a shortened life span, reducing the time-dependent accumulation of nuclei. This implies a reduced efficiency of uninucleate osteoclasts over multinucleate ones and we speculate on the reason for this.

Alleles↗

Study of sympathetic innervation of cranial bones by axonal transport of horseradish peroxidase in the rat: preliminary findings.

This study performed by intraneuronal tracing directly demonstrates the presence of sympathetic postganglionic fibers in the cranial vault of the rat. Superior cervical sympathetic ganglia were injected with horseradish peroxidase (HRP), and after a 48-hour period, to permit anterograde axonal transport, the animals were sacrificed after in situ perfusion. An area of the calvaria that included portions of the frontal and parietal bones was fixed, decalcified and sectioned. HRP-containing axons were localized in the developing frontal and parietal bones of the calvaria. Adrenergic innervation was not demonstrated in sutural tissue (superior sagittal, coronal or metopic) by this technique. To our knowledge, this study is the first to trace sympathetic nerve fibers in the rat calvaria by intra-axonal transport of HRP.

Animals↗

Effects of bone wax on rabbit cranial bone lesions.

The present study was designed to elucidate the reactions of cranial membranous bone to bone wax. In ten young rabbits, twenty parietal bone defects were created by drilling, the edges of which were partly extended using rongeur forceps to enable investigation of eventual thermal effects. Half of the marginal bone surrounding the lesions was covered by bone wax, the remainder serving as control. The animals were sacrificed 1 and 7 weeks after surgery, and block specimens prepared for light microscopy. Merely slight tissue reactions to the bone wax were discerned. Bony regeneration occurred mainly from the dura mater and the pericranium, but also from the bony rim. Reskeletalization was markedly impaired by the presence of bone wax. Heat generated by drilling caused reduced bone formation despite constant irrigation peroperatively. Clinical consequences are discussed.

Animals↗

Primary intraosseous malignant fibrous histiocytoma of the skull: a case report.

Malignant fibrous histiocytoma (MFH) is a rare primary neoplasm that constitutes less than 1% of the malignant tumors of bone, and involvement of the skull is very rare. We present a case of malignant fibrous histiocytoma of the skull, presenting an intraosseous lesion in a 43-yr-old woman. She had a rapidly growing, tender mass in the right parietal region. A plain radiograph showed an osteolytic lesion of the right parietal bone. Magnetic resonance imaging revealed that the lesion showed heterogeneous low signal intensity on T1-weighted images and slightly high signal intensity on T2-weighted images. No evidence of an extraosseous extension to the adjacent dura and soft tissue was found, and a wide excision of the parietal bone was performed. Histologically, the tumor was a typical MFH displaying pleomorphic spindle cells in a storiform pattern. The results of immunohistochemical stainings revealed that the tumor cells were positive for vimentin, alpha-1-antitrypsin, and p53, and negative for smooth muscle actin, S100 protein, desmin, and MyoD1. Three months later, a mainly cystic, recurrent mass was developed at the previously operated site. Before the resection, we first performed the percutaneous aspiration cytology, revealing diagnostic multinucleated pleomorphic cells. Thereafter, she had to receive repetitive resections of recurrent or residual lesions, and she died of postoperative meningoencephalitis two years after the first operation.

Actins↗

Congenital osteolipoma of the skull.

A unique case of congenital osteolipoma of the skull occurred. A 27-year-old woman had multiple hard tumors affecting the frontal and parietal bones, the rim of the orbit, the maxilla, the base of the skull, and the horizontal part of the mandible on the right side. The slowly growing tumor was first noticed in the right parietal bone when she was born. The partially excised right frontoparietal lesion was composed of deformed and sclerotic trabeculae of bone and mature adipose tissue that formed an osteolipoma, which was regarded as hamartomatous. Its pathogenesis was suggested as associated with maldifferentiation of the mesenchyme or its derivatives toward the osseous and adipose tissue at the early development of the cranium.

Adult↗

Osteopontin and bone metabolism: a histology and scintigraphy study in rats.

Osteopontin (OPN) is one of the major non-collagen proteins in extracellular bone matrix. To elucidate the function of OPN in bone metabolism, a cellular defect was created in parietal bone and tibia of 12 rats. In Group 1, the left defects were filled with OPN-coated hydroxyapatite (OPN-H). In Group 2, the right defects were filled with non-coated hydroxyapatite (N-H). In both groups, the contra lateral defects were used as control defects. In Group 3, OPN-H was inserted in the left defects and N-H in the right defects. Bone metabolism was measured by (45)Ca and technetium-99m methylene diphosphonate scintigraphy for 4 weeks. Scintigraphy did not show any significant differences in bone metabolism between the defects filled with OPN-H and N-H. A higher bone metabolism was measured between the parietal defects filled with OPN-H or N-H in comparison with the parietal control defects. This difference, however, was not significant and was less for tibia defects. Histological observation (7th week) shows less inflammatory cells at the tibia defects filled with OPN-H compared to the tibia defects filled with N-H. This study did not show any acceleration or inhibition of bone metabolism in parietal or tibia bone in rats, but there is some evidence that OPN might influence inflammatory cells in bone matrix.

Animals↗

Placement of autogeneic bone chips or bovine bone mineral in guided bone augmentation: a rabbit skull study.

PURPOSE: Our primary aim was to use a rabbit guided bone augmentation model to evaluate whether use of autogeneic bone grafts or bovine bone mineral (BBM) combined with a space-making barrier enhances bone augmentation compared with a barrier alone. MATERIALS AND METHODS: Sixteen rabbits were studied. In each rabbit, 2 titanium cylinders, each with 1 titanium lid, were placed subcutaneously in perforated slits made in the cortical bones, with their open ends facing the parietal bones. One cylinder was left empty and the other was filled with either autogeneic skull bone chips or BBM. Bone labels were injected after 4 and 11 weeks. After 12 weeks, the animals were sacrificed to obtain ground sections for histology and histomorphometry. RESULTS: Significantly more tissue was augmented in the 2 test groups than in the control group. Most of the autografts were resorbed, leaving only minute amounts in the upper third of the cylinders. Slender new bone trabeculae were distributed mainly from the contiguous bone plate that had no contact with the remaining graft material. In the BBM group, most of the BBM remained evenly distributed in the cylinder. In the upper third of the cylinder, the BBM was surrounded by soft connective tissue, while in the lower two thirds, mainly mineralized bone enclosed the BBM. Equal amounts of mineralized bone were found in both test groups. Comparisons of contact between bone and BBM on one hand and bone and bone cylinder wall on the other revealed that the greatest bone contact was with the BBM in the lower third of the cylinder. In the middle and upper third of the cylinder, bone-BBM contact and bone-cylinder wall contact were similar. Fluorescent label intensity was higher in the autograft group than in the BBM group. In all 3 groups the intensity of the early label was similar to that of the late label, indicating that the graft materials do not seem to retard mineralization. DISCUSSION: BBM was found to promote as much new bone as did autogeneic bone. In addition, BBM appears to have at least the same osteoconductive properties as titanium, provided BBM is contained in a stable environment. CONCLUSIONS: Placement of autogeneic bone or BBM in conjunction with a stiff space-making barrier generated more tissue than a barrier only. In this model, autogeneic bone chips and BBM augmented similar amounts of new mineralized bone.

Analysis of Variance↗

Osteoclast recruitment in mice is stimulated by (3-amino-1-hydroxypropylidene)-1,1-bisphosphonate.

Though some evidence suggests that bisphosphonates (BPs) act directly on osteoclasts to inhibit bone resorption, other evidence suggests that they inhibit the development of the osteoclast. We found an increase in osteoclast recruitment in 2-day-old mice given (3-amino-1-hydroxypropylidene)-1,1-bisphosphonate (APD). A threefold increase in 5-bromo-2'-deoxyuridine (BrdU)-labeled osteoclast nuclei was observed on mouse parietal bones 3 days after APD injection. This suggests that inhibition of osteoclast development is not an action of APD in mice of this age. The mechanism of the increased recruitment was investigated. As osteoclast progenitors were not detected on parietal bones in vitro, we looked for an increase in circulating monocytes to account for the recruitment. No such increase was found, but when 51Cr-labeled bone marrow was injected intraperitoneally into mice given APD there was an increase in accumulation of 51Cr in calvaria and in femur and tibia over controls. This increase did not occur when 51Cr-labeled erythrocytes or free 51Cr was injected. We conclude that APD causes increased recruitment of osteoclast precursors by increasing the avidity of bone for hematopoietically derived cells.

Animals↗