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Biomedical subjects

R C Ogle

Publications and source records attributed to R C Ogle.

At least 19 recordsLinked to original sources
PubMed2003

Mesenchymal stem cells from rat visceral fat exhibit multipotential differentiation in vitro.

Human subcutaneous fat-derived stem cells were recently shown to have the potential to differentiate in vitro into a variety of cell types, including adipocytes, osteoblasts, chondrocytes, and myoblasts (Zuk et al., Tissue Eng. 2001;7:211-228). Subcutaneous adipose tissue may therefore prove to be an easily acquired and abundant source of stem cells. Presently it is unclear whether mammals such as rats (which possess small or nonexistent subcutaneous fat pads) contain mesenchymal stem cells within the visceral fat of the abdominal cavity, or whether the visceral fat of any species contains stem cells. In this study we isolated and expanded a pool of mesenchymal cells from visceral fat of adult Sprague-Dawley rats and induced their differentiation in vitro into adipocytes, osteoblasts, neural cells, and chondrocytes. The differentiated phenotypes were verified by morphology as well as detection and expression of tissue-specific protein and mRNA. We conclude that despite well-documented differences in the metabolic and biochemical properties among anatomically distinct depots of fat, the visceral fat of rats contains adult mesenchymal stem cells with developmental potential similar to those isolated from subcutaneous fat in humans. Therefore, animals such as rats provide both a source of fat-derived stem cells and an immunocompetent, autologous host animal in which to investigate the capacity of the fat-derived cells to differentiate and form tissues in vivo.

Adipocytes↗
PubMed2001

Correction of coronal suture synostosis using suture and dura mater allografts in rabbits with familial craniosynostosis.

OBJECTIVE: Resynostosis following surgical correction of craniosynostosis is a common clinical correlate. Recent studies suggest that the dura mater is necessary to maintain suture patency. It has also been hypothesized that dura mater from synostotic individuals may provide aberrant biochemical signals to the osteogenic fronts of the calvaria, which result in premature suture fusion and subsequent resynostosis following surgery. This study was designed to test this hypothesis by surgically manipulating the coronal suture and dura mater in rabbits with familial craniosynostosis to prevent postsurgical resynostosis. DESIGN: Craniofacial growth and histomorphometric data were collected from 129 rabbits: 72 normal controls and 57 rabbits with bilateral coronal suture synostosis (15 unoperated on controls; 13 surgical controls; 9 dura mater transplant only; 10 suture transplant only; and 10 suture and dura mater transplant). At 10 days of age, all rabbits had radiopaque amalgam markers placed on either side of the coronal, frontonasal, and anterior lambdoidal sutures. At 25 days of age, 42 synostosed rabbits had a 3 to 5-mm wide coronal suturectomy. Coronal sutures and/or underlying dura mater allografts were harvested from same-aged, wild-type, isohistogenic control rabbits and transplanted onto the dura mater of synostosed host rabbits. Serial radiographs were taken at 10, 25, 42, and 84 days of age, and the suturectomy sites were harvested at 84 days of age in 44 rabbits and serially sectioned for histomorphometric examination. RESULTS: Results revealed that cranial vault growth was significantly (p < .05) improved following surgical release of the fused coronal suture compared with synostosed rabbits who were not operated on but was still significantly different (p < .05) from that of normal control rabbits. By 84 days of age, significant (p < .05) differences were noted in calvarial suture marker separation, cranial vault shape indices, and cranial base angles between rabbits with and without dura mater allografts, probably as a result of resynostosis of the suturectomy site or suture-only allografts. Qualitative histological examination revealed that at 84 days of age rabbits with suture and dura allografts had patent coronal sutures, suture-only allografts had fused coronal sutures with extensive endosteal hyperostosis, dura mater-only allografts had some new bone in the suturectomy site that resembled rudimentary osteogenic fronts, and suturectomy controls had extensive endosteal bone formation and resynostosis of the suturectomy site. Significantly (p < .05) more bone was found in the suturectomy sites of rabbits without dura mater allografts compared with rabbits with dura mater allografts. CONCLUSIONS: Results support the initial hypothesis that normal dura mater allografts will maintain suture or suturectomy site patency and allow unrestricted craniofacial growth. However, it is still unclear whether the dura mater from normal rabbits was providing biochemical signals to the transplanted sutures or suturectomy sites or simply acting as a barrier to prevent abnormal biochemical signals from the dura mater of synostosed rabbits from reaching the calvaria. The clinical and therapeutic implications of these procedures are discussed.

Analysis of Variance↗
PubMed1999

Insulinlike growth factor 1- and 2-augmented collagen gel repair of facial osseous defects.

BACKGROUND: Defects of the facial bone structure are common problems for the facial plastic surgeon. Native type 1 collagen gels (T1CGs) have been shown to mediate repair of facial critical-size defects in rat models. OBJECTIVE: To evaluate the efficacy of T1CG augmented with insulinlike growth factor (IGF) 1, IGF-2, and a combination of IGF-1 and IGF-2 on the repair of facial critical-size defects in a rodent model. METHODS: Twenty-four retired male breeder Sprague-Dawley rats were divided into 4 groups of 6 animals. Facial critical-size defects were created by removing the nasalis bones with a bone-cutting drill. Defects were treated with 300 pg of type 1 collagen gel (T1CG), T1CG augmented with 3 microg of IGF-1, T1CG augmented with 3 microg of IGF-2, or T1CG augmented with a combination of 3 microg of IGF-1 and 3 microg of IGF-2. After 30 days the animals were examined at necropsy with precise planimetry, histological analysis of new bone growth, and radiodensitometric analysis of bone thickness. RESULTS: Radiodensitometric measurements showed that IGF-2 augmentation resulted in greatest osseous healing, with measurements being statistically significant over those of all other groups (P< or = .03). Combination IGF-1 and IGF-2 had osseous healing that was intermediate between IGF-1 augmentation and IGF-2 augmentation alone, with measurements being statistically significant over those of unaugmented gels (P<.001) and IGF-1 augmentation (P< or = .03). Augmentation with IGF-1 resulted in healing that was significant over that of unaugmented gels (P< or = .04). CONCLUSION: Collagen gels augmented with IGF significantly enhance the osteoconductive repair of nasal critical-size defects in a rodent model, with IGF-2 showing highest efficacy.

Animals↗
PubMed1999

Repair of a rodent nasal critical-size osseous defect with osteoblast augmented collagen gel.

OBJECTIVES/HYPOTHESIS: Facial skeletal defects are a common challenge for the otolaryngologist. Type I collagen gels have shown promise in the repair of nonhealing critical size defects (CSDs) of facial bone by providing scaffolding for new bone growth by osteoblasts at the defect perimeter. The objective of the present study was to evaluate the effect that suspending osteoblasts within a type I collagen gel has on the repair of a rodent facial CSD. STUDY DESIGN: Randomized controlled trial using a rodent model. METHODS: A previously described facial CSD was created by removing the nasalis bones with a cutting burr to the level of the nasal mucosal membranes on 18 Sprague-Dawley rats. Groups of six animals were treated with an implant containing either 300 microg of type I collagen gel, 12 x 10(5) osteoblasts suspended within type I collagen gel, or 12 x 10(5) fibroblasts suspended within type I collagen gel for comparison. After 30 days the animals-were examined at necropsy with planimetry, histological analysis of new bone growth, and radiodensitometric analysis of bone thickness. RESULTS: All animals had complete coverage with a thin layer of bone. Histological sectioning revealed an increased thickness in the osteoblast augmented group. Radiodensitometric measurements revealed a statistically significant increase in bone repair in the osteoblast group compared with the collagen-only group (P < or = .0005) and the fibroblast group (P < or = .04). CONCLUSION: Type I collagen gels augmented with an osteoblastic suspension significantly enhance the repair of nasal CSDs in a rodent model. The use of cultured bone precursor cells represents a leap forward in osteoengineering.

Animals↗
PubMed1999

Repair of an osseous facial critical-size defect using augmented fibrin sealant.

OBJECTIVE: Osseous defects of the head and neck are a common challenge for the otolaryngologist. To develop improved reconstructive options, osteoconductive engineering experiments are being conducted. A nasal critical-size defect (CSD) model has previously been described in which less than 7% bone healing is observed over 6 months. An implant containing fibrin sealant with and without osteoprogenitor cells is evaluated in this model. STUDY DESIGN: Randomized controlled trial using a rodent model. METHODS: A nasal CSD was surgically created in 18 male retired breeder Sprague-Dawley rats. Six animals were not implanted with any material, six received fibrin sealant consisting of fibrin (25 mg/mL) and thrombin (1000 U/mL), and six were implanted with fibrin sealant and rat calvarial osteoprogenitor cells (1.8 x 10(6) cells/mL). Thirty days later, the animals were examined at necropsy by planimetry, histological analysis of new bone growth, and radiodensitometric analysis of bone thickness. RESULTS: A thin layer of bone covered the defect in all of the treated animals. A statistically significant increase in bone density (P < .05) between fibrin sealant plus osteoprogenitor cells and each of the other groups was shown using radiodensitometric analysis. Histological analysis also confirmed this difference. CONCLUSION: Osteoprogenitor cells contained within fibrin sealant result in a greater augmentation of bone regeneration than controls or fibrin sealant alone.

Animals↗
PubMed1998

Repair of nasal defects using collagen gels containing insulin-like growth factor 1.

OBJECTIVE: Facial osseous defects are a common and challenging problem for the otolaryngologist-head and neck surgeon. Current methods of repair including synthetic grafts, cadaveric material, and autologous tissue have drawbacks of foreign body reactions, infectious agent transmission, and the morbidity of a second surgical site. In the effort to develop an ideal technique for osseous reconstruction, a critical-size facial defect has previously been developed in the Sprague-Dawley rat. This model exhibits less than 10% healing by surface area over 6 months. A novel approach to osseous reconstruction is attempted using this model with type I collagen gel augmented with insulin-like growth factor 1 (IGF-1). STUDY DESIGN: Randomized controlled trial using a rodent model. METHODS: Twelve adult male Sprague-Dawley rats underwent a surgical procedure to produce a critical-size nasal defect by removing the nasal bones with a cutting burr. Six animals were repaired with 300 microg of type I collagen gel. Six animals were repaired with 300 microg of type I collagen gel augmented with 3.0 microg of IGF-1. Thirty days later, the animals were examined after necropsy. Precise planimetry, radiodensitometric analysis, and histologic sectioning were performed. RESULTS: All animals had complete coverage of this defect with a thin layer of bone. Radiodensitometric analysis indicated that there was a statistically significant (P < .037) increase in bone density in the collagen plus IGF-1 group compared with that of collagen only. In addition, histologic evaluation revealed increased bone density and thickness in the IGF-1 group. CONCLUSION: Type I collagen gel augmented with IGF-1 results in a significant increase in healing of a nasal critical-size defect in a rodent model.

Absorptiometry, Photon↗
PubMed1997

Laminin E8 alveolarization site: heparin sensitivity, cell surface receptors, and role in cell spreading.

Cell adhesion to amino acids 2179-2198 (SN-peptide) of the laminin-1 alpha1-chain is required for lung alveolar formation in vitro (M. L. Matter and G. W. Laurie. J. Cell Biol. 124: 1083-1090, 1994). The nature of the SN-peptide receptor(s) was probed with neutralizing anti-integrin monoclonal antibodies (MAb), cells lacking integrin subunits, soluble heparin, and SN-peptide columns. Cell adhesion and spreading studies confirmed the specificity of SN-peptide and revealed adhesion to be unaffected by inclusion of anti-beta1-, anti-alpha(2-6)- or anti-alpha(V)beta5-integrin MAb. Cells lacking beta1- or alpha6-integrin subunits were fully adherent. Adhesion was heparin, but not chondroitin sulfate or heparinase, sensitive, much as is alpha-dystroglycan-laminin-1 binding. Heparin eluted approximately 155- and 180-kDa cell-surface proteins from SN-peptide columns. An additional approximately 91-kDa protein was eluted by EDTA. All were unrecognized by anti-beta1-integrin MAb. SN-peptide therefore interacts with three cell-surface proteins for which the identity remains to be determined.

Amino Acid Sequence↗
PubMed1997

TGF-beta 1, TGF-beta 2, and TGF-beta 3 exhibit distinct patterns of expression during cranial suture formation and obliteration in vivo and in vitro.

Cranial sutures function as bone growth centers while themselves remaining unossified. Rat frontonasal sutures become obliterated by neonatal day 21 (N21), while coronal sutures do not fuse over the life of the animal. Coronal sutures induced to undergo osseous obliteration in vitro after removal of the dura mater were found to require soluble, heparin-binding factors present in dura mater to resist osseous obliteration. Transforming growth factor beta 1 (TGF-beta 1), beta 2, and beta 3, heparin-binding factors known to regulate bone cell proliferation and differentiation, were considered likely candidates. The presence and distribution of these factors in calvarial tissues both in vivo and in vitro were established by immunohistochemical analysis, while reverse transcription followed by polymerase chain reaction (RT/PCR) was employed to determine the presence of transcripts for these factors in mRNA isolated from microdissected dura mater. Results indicated that the presence of TGF-beta 1 and TGF-beta 2 were associated with developing coronal and frontonasal sutures, and that the continued presence of these factors was associated with osseous obliteration of the frontonasal suture. However, increased TGF-beta 3 immunoreactivity was associated with the coronal suture remaining unossified. RT/PCR demonstrated the presence of transcripts for TGF-beta 1, beta 2, and beta 3 in dural tissues isolated from rat calvaria. These data support the notion of a role for TGF-beta s in regulating cranial suture morphogenesis and establish the in vitro model as a valid system for examining mechanisms by which growth factors regulate both suture morphogenesis and bone growth at the suture site.

Animals↗
PubMed1997

Elevated levels of transforming growth factors beta 2 and beta 3 in lambdoid sutures from children with persistent plagiocephaly.

OBJECTIVE: To analyze the pertinent history and physical findings specific to the subset of patients with a progressive posterior skull deformity, requiring surgery to correct their deformity. PATIENTS: Since the Academy of Pediatrics issued its recommendation on supine positioning of infants to prevent sudden infant death syndrome (SIDS) in 1992, 73 children have presented to the University of Virginia Craniofacial Anomalies Clinic with posterior-skull deformities. The majority were successfully managed with conservative therapy, but in six patients, the deformity was severe and persistent, requiring surgical correction. All six children were older (7.5-12 mo), presenting with more severe morphologic appearances and a higher incidence of associated neurodevelopmental delay. Three had family backgrounds of isolated craniosynostosis. METHODS: Characteristics of these patients were examined to determine why they may have differed from those that responded to conservative management. Immunohistochemical staining of their lambdoid sutures was performed. RESULTS: Significantly increased staining for TGF-beta 2 and TGF-beta 3, potent stimulators of bone cell growth and differentiation, was seen in all 'affected' sutures from the flattened side of the skull, compared to unaffected sutures from the protruding side of the skull-a pattern similar to that seen during normal bony obliteration of calvarial sutures. CONCLUSION: The majority of patients with posterior plagiocephaly associated with positioning responded to conservative management, while a small subset of patients with persistent posterior skull deformation required surgical intervention. A genetic basis for the latter patients' persistent plagiocephaly, rather than positioning, cannot be ruled out. Genetics, prolonged external pressure against the sutures, or a combination of these factors may lead to permanently raised levels of growth factors in 'affected' sutures.

Cell Differentiation↗
PubMed1996

Nasal reconstruction using an osteoconductive collagen gel matrix.

BACKGROUND: Congenital malformations, granulomatous diseases, and trauma can all cause destruction of the nasal structural framework, resulting in functional nasal obstruction and altered facial cosmesis. Current methods of nasal reconstruction include cartilaginous and bony grafts, Silastic implants, and homograft only materials. However, these techniques have significant functional and cosmetic drawbacks and are not risk free. Native, isotonic, neutral-pH, space-filling type I collagen gels have been shown to mediate total repair of critical-size collagen grafts provide a framework for rapid intramembranous ossification and osteoconduction of bone from the perimeter of a defect, resulting in total bony coverage. OBJECTIVE: To evaluate a novel approach to nasal reconstruction using a major defect of the bony nasal dorsum with a type I collagen gel matrix. DESIGN: Sixteen retired male breeder Sprague-Dawley rats were divided into control and experimental groups. The nasal bones were exposed through a dorsal incision and completely removed with a bone-cutting drill to the level of the mucosal membranes of the nasal vestibule. Defects in the experimental animals were then implanted with 200 micrograms of type I collagen gel, with control animals receiving no inlay. After 6 weeks, the animals were examined with three-dimensional computed tomography before necropsy, at which time the defects were photographed, measured by planimetry, and sectioned for histologic analysis. RESULTS: Experimental defects were observed to manifest 100% surface area healing with a thin layer of bone using a type I collagen gel osteoconductive implant for nasal reconstruction. Conversely, control animals showed only a 5.7% (+/- 3.7% SD) healing by area. Histologic sections of the collagen gel implant revealed restoration of the anatomy with a thin plate of immature bone spanning the defect in continuity with the cartilage of the nasal septum and with apparent preservation of maxillonasalis suture lines. CONCLUSIONS: Native, isotonic, neutral-pH, space-filling collagen gels positively influenced the repair of large nasal defects, which showed minimal bone closure in untreated animals. Their use in this role merits further investigation.

Animals↗
PubMed1996

Altered production of laminin and nidogen by high and low metastatic variants of murine melanoma cells.

An altered ability to interact with and degrade extracellular matrix molecules is a common feature of the malignant phenotype. Although changes in the expression of matrix proteins in metastases in vivo are relatively well documented, little is known about the changes in matrix production by malignant cells in culture. Here we have examined the synthesis of the basement membrane components laminin and nidogen (entactin) by low and high metastatic variants of the K-1735 murine melanoma cells. Protein deposition was examined by western blotting as well as immunofluorescence; protein synthesis was examined by immunoprecipitation with specific antibodies. Gene expression was also evaluated by measuring steady-state mRNA levels using cDNA probes on northern and dot-blots. Laminin gamma 1 levels appeared to be similar in both high and low metastatic lines; however, the high metastatic lines had reduced levels of the laminin beta 1 chain. On the contrary, nidogen expression was observed only in the high metastatic lines. Traces of a laminin alpha chain were present only in immunoprecipitates of the low metastatic cells and could not be detected in the high metastatic cells. Both high and low metastatic cells deposited an extracellular matrix of basement membrane components, with laminin deposition decreased in high metastatic cells. Modified expression, production, and deposition of basement membrane components in high metastatic melanoma cells could be involved in their altered interactions with the extracellular matrix.

Animals↗
PubMed1995

Cranial sutures require tissue interactions with dura mater to resist osseous obliteration in vitro.

A chemically defined serum-free medium, which supports the development of bones and fibrous tissues of rat calvaria from nonmineralized mesenchymal precursor tissues, was employed to investigate tissue interactions between the dura matter and overlying tissues. Fetal calvarial rudiments from stages prior to bone and suture morphogenesis (fetal days 19 and 20) and neonatal calvarial rudiments with formed sutures (day 1) were cultured with and without associated dura mater. Removal of calvaria for in vitro culture allowed the examination of suture morphogenesis in the absence of tensional forces exerted on the sutures via fiber tracts in the dura mater originating in the cranial base. Ossification of frontal and parietal bones proceeded in a fashion comparable to development in vivo, but the cranial (coronal) sutures--primary sites for subsequent skull growth--were obliterated by osseous tissue union in the absence of dura mater. Bony fusion did not occur when rudiments were cocultured with dura mater on the opposite sides of 0.45 microns polycarbonate transwell filters, suggesting that the influence of dura mater on sutural obliteration was mediated by soluble factors rather than cell-cell or cell-matrix interactions. These results indicate that cell signaling mechanisms rather than biomechanical tensional forces are required for morphogenesis of the calvaria.

Animals↗
PubMed1995

A rapid in vitro assay of cellular chemomigration in an epithelial carcinoma cell line.

We have studied the chemomigration activity of an epithelial carcinoma cell line using a modified 96-well Boyden chamber apparatus consisting of upper and lower wells separated by an 8-microns pore polycarbonate filter. Cells from the malignant squamous carcinoma cell line A-431 were plated in the upper wells over a collagen IV-coated filter. In chemokinesis assays, the cells were allowed to migrate toward NIH 3T3 fibroblast-conditioned medium or control media in the lower wells for 6 hours at 37 degrees C with 10% CO2. A-431 cells preferentially migrate across the barrier toward conditioned media but not control media. Control normal keratinocytes showed no migration. A highly metastatic melanoma cell line and poorly metastatic melanoma cell line, in which chemomigration has been shown previously to correlate with metastatic potential, were used as positive and negative cellular controls. This system provides a rapidly quantifiable method by which the invasion characteristics of multiple cell lines can be studied simultaneously in a single assay using the 96-well format.

3T3 Cells↗
PubMed1995

Repair of critical size rat calvarial defects using extracellular matrix protein gels.

In this study the authors examined the capacity of gels of reconstituted basement membrane, laminin, and type I collagen to mediate repair of critical size defects in rat calvaria. Although autografts are widely used to repair bone defects caused by trauma or surgical treatment of congenital malformations, neoplasms, and infections, an adequate quantity of graft is not always available. Allogenic bone is readily available, but its use is associated with an increased incidence of nonunion, fatigue fracture, and rejection. Biologically active, purified components of basement membranes, which have been shown to promote osteogenic differentiation and angiogenesis in vitro and type I collagen (the major constituent of bone extracellular matrix) can be formed into native isotonic space-filling gels. In this study critical size calvarial defects were created in retired male Sprague-Dawley rats. Thirty-six animals were divided into seven groups. Group 1 (control) received no treatment for the defects. Group 2 animals were implanted with methylcellulose. Groups 3, 4, 5, and 6 were implanted with gels of type I collagen, reconstituted basement membrane, or laminin, respectively. The last group of three animals (Group 7) was implanted with 100 micrograms of type I collagen gels (identical to Group 3) and sacrificed at 20 weeks following a single CT scan to determine if complete healing could be obtained with this method given sufficient time. Except for rats in the type I collagen group that was evaluated by multiple computerized tomography (CT) scans biweekly from 2 to 12 weeks, bone repair was evaluated using CT at 12 weeks. Healing was quantified using three-dimensional reconstruction of CT. Following the final CT scan in each experimental group, animals were sacrificed, and a sample of tissues was evaluated by conventional histology. Animals treated with type I collagen gels showed 87.5% repair of the area of the defects at 12 weeks and 92.5% repair by 20 weeks. Increasing the gel volume 1.5 x accelerated complete repair to 3 months. Murine-reconstituted basement membrane and laminin gels induced 55.5% and 46.3% repair, respectively, at 3 months. In untreated control animals 7% repair of the area of the defects showed at 3 months. Histological analysis confirmed new bone formation in partial and completely healed defects. Bioengineered native collagen gels may have wide applicability for bone repair as an alternative bone graft material alone, in combination with autograft or marrow aspirate, or as a delivery system for osteogenic growth factors.

Animals↗
PubMed1994

In the absence of periosteum, transplanted fetal and neonatal rat coronal sutures resist osseous obliteration.

Normal craniofacial development depends on expansion of the cranial vault by growth at the sutures. Inappropriate development of the sutures leads to global disruption of patterns of craniofacial growth. Tissue interactions between dura mater and suture matrix play a critical role in the phenotypic maintenance of cranial sutures. However, the function of the periosteum in this process remains under-reported and controversial. To examine the contribution of periosteum in maintaining the patency of coronal sutures, fetal and neonatal rat coronal sutures were transplanted to surgically created defects in adult rat host parietal bones. These sutures were examined for their ability to persist in the host milieu in the presence and absence of both donor and host periosteum. This study established that removal of both host and transplant periosteum, unlike removal of dura mater, did not lead to obliteration of either fetal or neonatal sutures. Thus, periosteum and dura mater are nonequivalent tissues with respect to influence on suture patency.

Animals↗
PubMed1993

Tissue interactions with underlying dura mater inhibit osseous obliteration of developing cranial sutures.

Cranial sutures play a critical role in calvarial morphogenesis, serving as growth centers during skull development. Both biomechanical tensile forces originating in the cranial base and biochemical factors present in dura mater have been postulated as determinants of suture morphogenesis and patency. A rat transplant model free of the putative biomechanical influence of the dura and cranial base was used to investigate the role of the dura mater in both the initial morphogenesis and maintenance of sutures during skull growth. Day 19 fetal presumptive (F19) and day 1 neonatal differentiated (N1) coronal sutures, including associated frontal and parietal bones, were transplanted with or without underlying dura mater to the center of adult parietal bones. After 1, 2, and 3 weeks, transplanted tissues were examined histologically and histomorphometrically to determine whether sutures formed and whether they were obliterated by ossification in the absence of dura mater. Both F19 and N1 sutures remained patent for 2 weeks either in the presence or the absence of transplant dura mater. However, at 3 weeks, in the absence of transplant dura mater, sutures were obliterated by bone, while in the presence of dura mater sutures resisted ossification, demonstrating an essential requirement for interactions with the transplant dura mater in maintaining functional sutures. Both F19 and N1 transplants showed comparable bone growth (cross-sectional surface area), regardless of the presence of transplant dura mater. These experiments suggest that tissue interactions of a biochemical nature, rather than biomechanical forces generated through the cranial base, are required to maintain the suture as a non-ossified growth center. Furthermore, while the presence of dura mater was essential for maintenance of suture patency, fetal dura mater was not required for initial suture formation.

Animals↗
PubMed1993

Calvarial deformity regeneration following subtotal craniectomy for craniosynostosis: a case report and theoretical implications.

We describe an infant with combined sagittal and unilateral coronal synostosis who underwent "total vault" craniectomy for skull reshaping. The operative procedure was interrupted without replacement of the calvarial bone grafts. Follow-up over the ensuing 2 months revealed regeneration of the entire cranium and supraorbital rims, as well as (in contrast to earlier reports) redevelopment of fusion within the suture at the same site noted in the initial operation, associated with similar skull deformity. These observations are reviewed with special emphasis on the theoretical implications for the etiology of craniosynostosis and skull deformity.

Bone Regeneration↗