CT Analysis (ct + analysis)

Distribution by Scientific Domains

Selected Abstracts

Mutations in the Insulin-Like Factor 3 Receptor Are Associated With Osteoporosis,

Alberto Ferlin
Abstract Introduction: Insulin-like factor 3 (INSL3) is produced primarily by testicular Leydig cells. It acts by binding to its specific G protein,coupled receptor RXFP2 (relaxin family peptide 2) and is involved in testicular descent during fetal development. The physiological role of INSL3 in adults is not known, although substantial INSL3 circulating levels are present. The aim of this study was to verify whether reduced INSL3 activity could cause or contribute to some signs of hypogonadism, such as reduced BMD, currently attributed to testosterone deficiency. Materials and Methods: Extensive clinical, biochemical, and hormonal study, including bone densitometry by DXA, was performed on 25 young men (age, 27,41 yr) with the well-characterized T222P mutation in the RXFP2 gene. Expression analysis of INSL3 and RXFP2 on human bone biopsy and human and mouse osteoblast cell cultures was performed by RT-PCR, quantitative RT-PCR, and immunohistochemistry. Real-time cAMP imaging analysis and proliferation assay under the stimulus of INSL3 was performed on these cells. Lumbar spine and femoral bone of Rxfp2- deficient mice were studied by static and dynamic histomorphometry and ,CT, respectively. Results: Sixteen of 25 (64%) young men with RXFP2 mutations had significantly reduced BMD. No other apparent cause of osteoporosis was evident in these subjects, whose testosterone levels and gonadal function were normal. Expression analyses showed the presence of RXFP2 in human and mouse osteoblasts. Stimulation of these cells with INSL3 produced a dose- and time-dependent increase in cAMP and cell proliferation, confirming the functionality of the RXFP2/INSL3 receptor,ligand complex. Consistent with the human phenotype, bone histomorphometric and ,CT analyses of Rxfp2,/, mice showed decreased bone mass, mineralizing surface, bone formation, and osteoclast surface compared with wildtype littermates. Conclusions: This study suggests for the first time a role for INSL3/RXFP2 signaling in bone metabolism and links RXFP2 gene mutations with human osteoporosis. [source]

The Prospects of Carrying and Releasing Drugs Via Biodegradable Magnesium Foam,

Eli Aghion
Abstract Powder metallurgy technology was used to produce magnesium foams in order to evaluate their ability to perform as a solid biodegradable platform for drug delivery. The amount and delivery time of the released drug (gentamicin) was controlled by the level of space-holding particles (spacer) that was mixed with the magnesium powder prior to the sintering process. Metallurgical examination of the magnesium foams was carried out using optical and scanning electron microscopy (SEM) and X-ray diffraction analysis. Microtomography CT analysis was used to evaluate the structural characteristics of the magnesium foams and their internal interconnected porosity configuration. The corrosion behavior of the magnesium foams was evaluated by immersion test in a simulated physiological environment (PBS solution). The absorption of gentamicin was obtained by immersing magnesium foams in concentrated gentamicin solutions within a vacuum chamber, followed by water evaporation. The detection of gentamicin in PBS solution was carried out using a Fluorescence Polarimetry analyzer. The results show that the release profile of gentamicin from magnesium foam with 10 and 25% spacer in PBS solution was in accord with common dissolution kinetics of an active ingredient from polymeric drug delivery systems. [source]

Cyclic fatigue resistance and three-dimensional analysis of instruments from two nickel,titanium rotary systems

N. M. Grande
Abstract Aim, To determine how instrument design affects the fatigue life of two nickel,titanium (Ni,Ti) rotary systems (Mtwo and ProTaper) under cyclic fatigue stress in simulated root canals. Methodology, Cyclic fatigue testing of instruments was performed in stainless steel artificial canals with radii of curvature of 2 or 5 mm and an angle of curvature of 60°. A total of 260 instruments were rotated until fracture occurred and the number of cycles to failure were recorded. The morphology of Ni,Ti rotary instruments was investigated by measuring the volume of millimetre slices of each instrument size starting from the tip to the shank by means of ,CT analysis. The fracture surface of three representative samples of each size was analysed by scanning electron microscopy (SEM). Data were analysed by one-way anova, Holm t -test, paired t -test and linear regression; the significance was determined at the 95% confidence level. Results, Cycles to failure significantly decreased as the instrument volume increased for both the radii of curvature tested (P < 0.01). The radius of curvature had a statistically significant influence on the fatigue life of the instruments (P < 0.05). Larger instruments underwent fracture in less time under cyclic stress than smaller ones. SEM evaluation showed typical features of fracture through fatigue failure. Conclusions, The metal volume in the point of maximum stress during a cyclic fatigue test could affect the fatigue life of Ni,Ti rotary instruments. The larger the metal volume, the lower the fatigue resistance. [source]

Targeted Deletion of the Sclerostin Gene in Mice Results in Increased Bone Formation and Bone Strength,,

Xiaodong Li
Abstract Introduction: Sclerosteosis is a rare high bone mass genetic disorder in humans caused by inactivating mutations in SOST, the gene encoding sclerostin. Based on these data, sclerostin has emerged as a key negative regulator of bone mass. We generated SOST knockout (KO) mice to gain a more detailed understanding of the effects of sclerostin deficiency on bone. Materials and Methods: Gene targeting was used to inactivate SOST and generate a line of SOST KO mice. Radiography, densitometry, ,CT, histomorphometry, and mechanical testing were used to characterize the impact of sclerostin deficiency on bone in male and female mice. Comparisons were made between same sex KO and wildtype (WT) mice. Results: The results for male and female SOST KO mice were similar, with differences only in the magnitude of some effects. SOST KO mice had increased radiodensity throughout the skeleton, with general skeletal morphology being normal in appearance. DXA analysis of lumbar vertebrae and whole leg showed that there was a significant increase in BMD (>50%) at both sites. ,CT analysis of femur showed that bone volume was significantly increased in both the trabecular and cortical compartments. Histomorphometry of trabecular bone revealed a significant increase in osteoblast surface and no significant change in osteoclast surface in SOST KO mice. The bone formation rate in SOST KO mice was significantly increased for trabecular bone (>9-fold) at the distal femur, as well as for the endocortical and periosteal surfaces of the femur midshaft. Mechanical testing of lumbar vertebrae and femur showed that bone strength was significantly increased at both sites in SOST KO mice. Conclusions:SOST KO mice have a high bone mass phenotype characterized by marked increases in BMD, bone volume, bone formation, and bone strength. These results show that sclerostin is a key negative regulator of a powerful, evolutionarily conserved bone formation pathway that acts on both trabecular and cortical bone. [source]

Enhanced Chondrogenesis and Wnt Signaling in PTH-Treated Fractures,

Sanjeev Kakar
Abstract Studies have shown that systemic PTH treatment enhanced the rate of bone repair in rodent models. However, the mechanisms through which PTH affects bone repair have not been elucidated. In these studies we show that PTH primarily enhanced the earliest stages of endochondral bone repair by increasing chondrocyte recruitment and rate of differentiation. In coordination with these cellular events, we observed an increased level of canonical Wnt-signaling in PTH-treated bones at multiple time-points across the time-course of fracture repair, supporting the conclusion that PTH responses are at least in part mediated through Wnt signaling. Introduction: Since FDA approval of PTH [PTH(1,34); Forteo] as a treatment for osteoporosis, there has been interest in its use in other musculoskeletal conditions. Fracture repair is one area in which PTH may have a significant clinical impact. Multiple animal studies have shown that systemic PTH treatment of healing fractures increased both callus volume and return of mechanical competence in models of fracture healing. Whereas the potential for PTH has been established, the mechanism(s) by which PTH produces these effects remain elusive. Materials and Methods: Closed femoral fractures were generated in 8-wk-old male C57Bl/6 mice followed by daily systemic injections of either saline (control) or 30 ,g/kg PTH(1,34) for 14 days after fracture. Bones were harvested at days 2, 3, 5, 7, 10, 14, 21, and 28 after fracture and analyzed at the tissue level by radiography and histomorphometry and at the molecular and biochemical levels level by RNase protection assay (RPA), real-time PCR, and Western blot analysis. Results: Quantitative ,CT analysis showed that PTH treatment induced a larger callus cross-sectional area, length, and total volume compared with controls. Molecular analysis of the expression of extracellular matrix genes associated with chondrogenesis and osteogenesis showed that PTH treated fractures displayed a 3-fold greater increase in chondrogenesis relative to osteogenesis over the course of the repair process. In addition, chondrocyte hypertrophy occurred earlier in the PTH-treated callus tissues. Analysis of the expression of potential mediators of PTH actions showed that PTH treatment significantly induced the expression of Wnts 4, 5a, 5b, and 10b and increased levels of unphosphorylated, nuclear localized ,-catenin protein, a central feature of canonical Wnt signaling. Conclusions: These results showed that the PTH-mediated enhancement of fracture repair is primarily associated with an amplification of chondrocyte recruitment and maturation in the early fracture callus. Associated with these cellular effects, we observed an increase in canonical Wnt signaling supporting the conclusion that PTH effects on bone repair are mediated at least in part through the activation of Wnt-signaling pathways. [source]

Noggin Inhibits Postoperative Resynostosis in Craniosynostotic Rabbits,

Gregory M Cooper PhD
Abstract Inhibition of bone formation after surgery to correct craniosynostosis would alleviate the need for secondary surgeries and decrease morbidity and mortality. This study used a single dose of Noggin protein to prevent resynostosis and improve postoperative outcomes in a rabbit model of craniosynostosis. Introduction: Craniosynostosis is defined as the premature fusion of one or more of the cranial sutures, which causes secondary deformations of the cranial vault, cranial base, and brain. Current surgical intervention involves extirpation of the fused suture to allow unrestricted brain growth. However, resynostosis of the extirpated regions often occurs. Several bone morphogenetic proteins (BMPs), well-described inducers of ossification, are involved in bone healing. This study tested the hypothesis that a postoperative treatment with Noggin, an extracellular BMP inhibitor, can inhibit resynostosis in a rabbit model of human familial nonsyndromic craniosynostosis. Materials and Methods: Thirty-one New Zealand white rabbits with bilateral coronal suture synostosis were divided into three groups: (1) suturectomy controls (n = 13); (2) suturectomy with BSA in a slow-resorbing collagen vehicle, (n = 8); and (3) suturectomy with Noggin in a slow-resorbing collagen vehicle (n = 10). At 10 days of age, a 3 × 15-mm coronal suturectomy was performed. The sites in groups 2 and 3 were immediately filled with BSA-loaded gel or Noggin-loaded gel, respectively. Serial 3D-CT scan reconstructions of the defects and standard radiographs were obtained at 10, 25, 42, and 84 days of age, and the sutures were harvested for histological analysis. Results: Radiographic analysis revealed that Noggin-treated animals had significantly greater coronal suture marker separation by 25 days and significantly greater craniofacial length at 84 days of age compared with controls. 3D-CT analysis revealed that Noggin treatment led to significantly greater defect areas through 84 days and to increased intracranial volumes at 84 days of age compared with other groups. Histological analysis supported CT data, showing that the untreated and BSA-treated groups had significant healing of the suturectomy site, whereas the Noggin-treated group had incomplete wound healing. Conclusions: These data support our hypothesis that inhibition of BMP activity using Noggin may prevent postoperative resynostosis in this rabbit model. These findings also suggest that Noggin therapy may have potential clinical use to prevent postoperative resynostosis in infants with craniosynostosis. [source]

Osteoblast Deletion of Exon 3 of the Androgen Receptor Gene Results in Trabecular Bone Loss in Adult Male Mice,

Amanda J Notini
Abstract The mechanism of androgen action on bone was studied in male mice with the AR deleted in mature osteoblasts. These mice had decreased trabecular bone volume associated with a decrease in trabecular number, suggesting that androgens may act directly on osteoblasts to maintain trabecular bone. Introduction: Androgens modulate bone cell activity and are important for the maintenance of bone mass. However, the mechanisms by which they exert these actions on bone remain poorly defined. The aim of this study was to investigate the role of androgens acting through the classical androgen receptor (AR) signaling pathways (i.e., DNA-binding dependent pathways) in osteoblasts using male mice in which exon 3 of the AR gene was deleted specifically in mature osteoblasts. Materials and Methods: Mice with a floxed exon 3 of the AR gene were bred with Col 2.3-cre transgenic mice, in which Cre recombinase is expressed in mineralizing osteoblasts. The skeletal phenotype of mutant mice was assessed by histomorphometry and quantitative ,CT at 6, 12, and 32 weeks of age (n = 8 per group). Wildtype, hemizygous exon 3 floxed and hemizygous Col 2.3-cre male littermates were used as controls. Data were analyzed by one-way ANOVA and Tukey's posthoc test. Results: ,CT analysis of the fifth lumbar vertebral body showed that these mice had reduced trabecular bone volume (p < 0.05) at 32 weeks of age compared with controls. This was associated with a decrease in trabecular number (p < 0.01) at 12 and 32 weeks of age, suggesting increased bone resorption. These effects were accompanied by a reduction in connectivity density (p < 0.01) and an increase in trabecular separation (p < 0.01). A similar pattern of trabecular bone loss was observed in the distal femoral metaphysis at 32 weeks of age. Conclusions: These findings show that inactivation of the DNA binding,dependent functions of the AR, specifically in mature osteoblasts in male mice, results in increased bone resorption and decreased structural integrity of the bone, leading to a reduction in trabecular bone volume at 32 weeks of age. These data provide evidence of a role for androgens in the maintenance of trabecular bone volume directly through DNA binding,dependent actions of the AR in mature osteoblasts. [source]

Inhibitory helix-loop-helix transcription factors Id1/Id3 promote bone formation in vivo

Yukiko Maeda
Abstract Bone formation is under the control of a set of transcription factors. Ids are inhibitory helix-loop-helix (HLH) transcription factors and expression of Id genes in osteoblasts is under the control of calciotropic agents such as BMP and vitamin D. However, the function of Ids during bone formation in vivo has not yet been elucidated. We, therefore, examined the role of Id1 and Id3 in the regulation of bone metabolism in vivo. Using wild type and Id1/Id3 heterozygous knockout mice, we analyzed calvarial bone formation in the suture by X-ray picture, proliferation, and mineralization activities of primary calvarial osteoblasts by MTT assay and alizarin red staining and onthotopic in vivo bone formation by BMP injection onto calvaria and micro CT analysis. The width of calvarial sutures was reduced by more than 50% in Id1/Id3 heterozygous knock out mice. Analyses on the cellular basis for the mechanism underlying the defects in the mutant mice revealed suppression of proliferation and mineralization in osteoblasts derived from Id1/Id3 heterozygous knock out mice. Furthermore, Id1/Id3 heterozygous knock out mice suppressed BMP-induced bone formation in vivo. These results indicated that Id1 and Id3 are positive factors to promote bone formation in vivo. © 2004 Wiley-Liss, Inc. [source]

Computer-assisted tibia preparation for total ankle arthroplasty: a cadaveric study

Samuel B. Adams Jr
Abstract Background Most surgeons performing total ankle arthroplasty (TAA) suggest that accurate tibial preparation perpendicular to the tibial shaft axis improves outcomes. Recent studies demonstrate that computerized surgical navigation significantly improves the accuracy of tibial preparation in total knee arthroplasty (TKA). Methods We performed the tibial preparation for TAA in seven matched pairs of cadaver lower extremities. One set of matched pairs was prepared using the conventional external tibial alignment guide/cutting block from the Scandanavian Total Ankle Replacement system (STAR, Waldemar Link GmbH & Co., Hamburg, Germany) under fluoroscopic guidance. The second set of matched pairs was prepared using the VectorVision® navigation system (BrainLAB, Munich, Germany), with currently available computed tomography (CT)-based TKA software. Pre-operative CT data were used to assess the tibial mechanical axis. In both groups, accuracy of the tibial plafond preparation relative to the tibial shaft axis in both the coronal and sagittal planes was determined by fluoroscopic, radiographic and CT analysis. Results Mean values of the tibial cut for the set of matched-pair tibiae prepared by the conventional surgical method ranged across the three imaging assessment techniques in the ranges 89.3,89.6° (coronal plane, anteroposterior) and 90.3,90.4° (sagittal plane, lateral). For the computer-navigated set, the values were 89.7,89.9° (coronal) and 89.1,89.4° (sagittal). Comparison between the conventional and computer-navigated tibial measurements were not different at the 95% confidence interval (CI) for CT, fluoroscopy or radiographic assessments. Conclusions Our results demonstrate that accuracy of TAA tibial preparation using computer-navigation equals that of the conventional technique performed by a foot and ankle surgeon experienced in TAA. We anticipate that this investigation will encourage the development of computer-navigation applications specific to TAA, with the potential of improving accuracy over conventional methods. Copyright © 2008 John Wiley & Sons, Ltd. [source]

CT analysis after distraction osteogenesis in Pierre Robin Sequence

Saswata Roy MD
Abstract Objectives/Hypothesis: Early mandibular lengthening by distraction osteogenesis provides an alternative to traditional methods of airway management in infants with Pierre Robin sequence (PRS). Little evidence in the medical literature quantitatively demonstrates the changes in skeletal, soft tissue, and hypopharyngeal spaces with mandibular distraction. Study Design: Prospective analysis of a cohort of three patients with PRS. Methods: We reviewed a series of infants with PRS and severe upper airway obstruction who underwent mandibular distraction. The infants underwent mandibular lengthening with the same internal, unidirectional distraction osteogenesis device. Standardized serial computed tomography (CT) scans were obtained according to established protocol. Computed tomography data were extracted and analyzed with medical image analysis software for mandibulo-maxillary arch harmony, symmetry, hypopharyngeal airway volume, geniohyoid distance, distraction osteogenesis bone volume, and mandibular length. Results: Mandibulo-maxillary alveolar ridge distances were corrected to 0.5 mm after distraction. Clinical examination showed good arch harmony without open-bite or cross-bite deformities. Mandibular ramus was lengthened by 19.5%; the body, 43.4%. After distraction, total mandibular length was increased by 26.2%; hypopharyngeal airway volume, 192%; posterior distance from pharyngeal wall to tongue base, 198.9%; and geniohyoid distance, 14.1%. Conclusions: Unidirectional internal microdistractors can achieve good mandibulo-maxillary arch harmony. Hypopharyngeal airway volume increases substantially, with an even greater increase in distance between tongue base and posterior pharyngeal wall. As the distal mandibular segment is distracted, the hyoid moves anteriorly, with minor increase in geniohyoid relationship. Internal mandibular microdistraction devices represent a substantial advance in airway obstruction management in infants with micrognathia. Laryngoscope, 2009 [source]

Bone formation following sinus grafting with autogenous bone-derived cells and bovine bone mineral in minipigs: preliminary findings

Gabor Fuerst
Abstract: Bone formation in a sinus grafted with a cell-free scaffold requires the presence of local progenitor cells that differentiate into osteoblasts. The purpose of this study was to examine the effect of culture expanded autogenous bone-derived cells (ABC) with bovine bone mineral (BBM) on bone formation after single-stage sinus grafting in minipigs. Bone biopsies from the iliac crest were harvested 4 weeks prior to sinus grafting and ABC were culture expanded in vitro. The sinuses of five adult minipigs were grafted. In one sinus of each minipig the space between Schneider's membrane (SM) and the sinus wall was grafted with ABC (325,000 cells per sinus, on average) and BBM. In the other sinus, BBM alone was used. The animals were sacrificed after 12 weeks. One block of each grafted area was prepared by saw cutting and the amount of newly formed bone was analysed by micro-computed tomography (,-CT). The addition of ABC to BBM significantly increased the amount of newly formed bone compared with BBM alone on ,-CT analysis (ABC+BBM: 29.86±6.45% vs. BBM: 22.51±7.28% (P=0.016)). Bone formation was increased near SM (ABC+BBM: 20.7±4.5% vs. BBM: 15.43±3.62% (P=0.009)) and in the middle zone of the grafting material (ABC+BBM: 31.63±7.74% vs. BBM: 22.5±7.91% (P=0.001)), but not near the local host bone (ABC+BBM: 37.23±8.23% vs. BBM: 28.42±12.54% (P=0.15)). These preliminary findings indicate that supplementation of cell-free grafting material with culture expanded ABC can stimulate bone formation in areas with low bone-forming capacity. Résumé La néoformation osseuse dans un sinus grefféà l'aide d'un échafaudage acellulaire requiert la présence de cellules progénitrices locales qui se différencient en ostéoblastes. Le but de cette étude a été d'examiner l'effet de cellules dérivées de l'os autogène (ABC) avec expansion par culture avec un minéral osseux bovin (BBM) sur la formation osseuse après une greffe sinusale en une étape chez le mini-porc. Des biopsies osseuses de la crête iliaque ont été prélevées quatre semaines avant la greffe sinusale et les ABC ont été placées en culture in vitro. Les sinus de cinq mini-porcs adultes ont été greffés. Dans un sinus de chaque mini-porc l'espace entre la membrane de Schneider et la paroi sinusale a été greffé avec les ABC (en moyenne 325 000 cellules/sinus) et BBM. Dans l'autre sinus, BBM seul a été utilisé. Les animaux ont été euthanasiés après douze semaines. Un bloc de chaque aire greffée a été scié et la quantité d'os néoformé a été analysée par tomographie par micro-ordinateur (,-CT). L'addition d'ABC au BBM augmentait significativement la quantité d'os néoformé comparée à l'utilisation du BBM seul lors de l'analyse micro-CT [ABC+BBM : 29,9±6,5% vs BBM : 22,5±7,3% (P=0,016)]. La formation osseuse était augmentée près de la membrane de Schneiderian [ABC+BBM : 20,7±4,5 vs BBM : 15,4±3,6% (P=0,009)] et dans la zone moyenne du matériel greffé [ABC+BBM : 31,6±7,7% vs BBM : 22,5±7,9 (P=0,001)], mais pas dans la région proche de l'hôte (ABC+BBM : 37,2±8,2% vs BBM : 28,4±12,5% (P=0,150). Ces découvertes préliminaires indiquent que l'addition à un matériau acellulaire de ABC en culture d'expansion pouvait stimuler la formation osseuse dans des zones avec des faibles capacités de formation osseuse. Zusammenfassung Knochenformation nach Sinusaugmentation mit autologen Zellen knöchernen Ursprungs und bovinem Knochenmineral in Minipigs: erste Ergebnisse Die Bildung von neuem Knochen im augmentierten Sinus mit einer zellfreien Matrix benötigt lokale Progenitorzellen, welche sich in Osteoblasten differenzieren können. Das Ziel dieser Studie war, den Effekt von in Kultur gezüchteten autologen Zellen knöchernen Ursprungs (ABC) mit bovinem Knochenmineral (BBM) auf die Knochenbildung nach Sinusaugmentation in Minipigs zu untersuchen. Knochenbiopsien vom Beckenkamm wurden 4 Wochen vor der Sinusaugmentation entnommen und die ABC in vitro in einer Kultur vermehrt. Die Kieferhöhlen von 5 ausgewachsenen Minipigs wurden augmentiert. Bei einer Kieferhöhle jedes Minipigs wurde der Raum zwischen der Schneider'schen Membran und der Sinuswand mit ABC (325,000 Zellen pro Sinus in Durchschnitt) und BBM aufgefüllt. In der anderen Kieferhöhle wurde BBM allein verwendet. Die Tiere wurden nach 12 Wochen geopfert. Von jeder augmentierten Region wurde mittels Sägeschnitt ein Block präpariert und die Menge an neu gebildetem Knochen wurde durch Mikro-Computertomographie (,-CT) analysiert. Die Zugabe von ABC zu BBM bewirkte in der ,-CT Analyse eine signifikante Zunahme des neu gebildeten Knochens im Vergleich zu BBM allein (ABC+BBM: 29.86±6.45% gegenüber BBM. 22.51±7.28% (P=0.016)). Die Knochenbildung hatte im Bereich der Schneider'schen Membran (ABC+BBM: 20.7±4.5% gegenüber BBM: 15.43±3.62%(P=0.009)) und in der Mittelzone des Transplantatmaterials (ABC+BBM: 31.63±7.74% gegenüber BBM: 22.5±7.91% (P=0.001)) zugenommen, aber nicht in der Nähe des lokalen Wirtsknochens (ABC+BBM: 37.23±8.23% gegenüber BBM: 28.42±12.54% (P=0.15)). Diese ersten Resultate zeigen, dass der Zusatz von in Kultur gezüchteten ABC zu zellfreien Transplantatmaterialien die Knochenbildung in Regionen mit niedriger Knochenbildungskapazität stimulieren kann. Resumen La formación de nuevo hueso en un seno injertado con una estructura libre de células requiere la presencia de células progenitoras que se diferencien en osteoblastos. El propósito de este estudio fue examinar el efecto de células autógenas derivadas de hueso de cultivo expandido (ABC) con mineral de hueso bovino (BBM) en la formación de hueso tras un injerto del seno en una sola fase en minicerdos. Se tomaron biopsias de hueso de la cresta iliaca 4 semanas antes del injerto del seno y se cultivaron expandidamente las células ABC in vitro. Se injertaron los senos de 5 minicerdos. En un seno de cada minicerdo el espacio entre la membrana de Schneider y la pared del seno se injertó con ABC (325,000 células por seno, de media) y BBM. En el otro seno se uso BBM únicamente. Los animales se sacrificaron tras 12 semanas. Se preparó un bloque de cada área injertada por medio de una sierra y se analizó la cantidad de hueso neoformado por medio de micro tomografía computarizada (,-CT). La adición de ABC a BBM incrementó significativamente la cantidad de hueso neoformado comparado con BBM solo en el análisis de ,-CT [ABC+BBM: 29.86±6.45% vs. BBM: 22.51±7.28% (P=0.016)]. La formación del hueso se incrementó cerca de la membrana de Schneider [ABC+BBM: 20.7±4.5% vs. BBM: 15.43±3.62% (P=0.009)] y en la zona media de del material de injerto [ABC+BBM: 31.63±7.74% vs. BBM: 22.5±7.91% (P=0.001], pero no cerca del hueso huésped local [ABC+BBM: 37.23±8.23% vs. BBM: 28.42±12.54% (P=0.15)]. Estos hallazgos preliminares indican que la suplementación de injertos sin células con ABC de cultivo expandido puede estimular la formación de hueso en áreas con baja capacidad de formación de hueso. [source]