Radiographic and Micro—Computed Tomographic Imaging of Lipopolysaccharide-Mediated Bone Resorption

2009 ◽  
Vol 118 (5) ◽  
pp. 391-396 ◽  
Author(s):  
Robert Nason ◽  
Dong H. Lee ◽  
Jae Y. Jung ◽  
Richard A. Chole
Keyword(s):  
Bone Resorption ◽  
Chronic Otitis Media ◽  
Plain Radiography ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Gram Negative ◽  
Successful Model ◽  
Computed Tomographic ◽  
Myeloid Differentiation Factor

Objectives: Chronic otitis media and cholesteatomas cause hearing loss as a result of bony erosion. This bone resorption is known to be more aggressive when cholesteatomas become infected. The most common organism isolated from both diseases is the gram-negative bacterium Pseudomonas aeruginosa. Lipopolysaccharide (LPS), a major virulence factor found in the gram-negative bacterial cell wall, is well known to incite inflammatory bone resorption. The mechanisms underlying this process, however, are poorly understood. In this study, we developed a mouse model of calvarial osteolysis in which resorption was reliably imaged by plain radiography and micro–computed tomography (micro-CT). Methods: A murine calvarial model was developed to study bone resorption induced by P aeruginosa LPS. Calvariae from wild-type and knockout mice used in this model were imaged by plain radiography and micro-CT. Results: A high degree of correlation between plain radiography and micro-CT was identified (R2 = 0.8554). Furthermore, maximal LPS-induced bone resorption required functioning toll-like receptor (TLR) 2, TLR4, and myeloid differentiation factor 88 (MyD88). Conclusions: We have developed a successful model of inflammatory osteolysis in which plain radiography can reliably delineate induced bone resorption. In vivo, we have shown that P aeruginosa LPS signals via TLR2, as well as TLR4 through MyD88.

scholarly journals Deferoxamine Reduces Inflammation and Osteoclastogenesis in Avulsed Teeth

2021 ◽  
Vol 22 (15) ◽  
pp. 8225
Author(s):  
Ko Eun Lee ◽  
Mijeong Jeon ◽  
Seunghan Mo ◽  
Hyo-Seol Lee ◽  
Je Seon Song ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Alveolar Bone ◽  
Root Surface ◽  
Tartrate Resistant Acid Phosphatase ◽  
Micro Ct ◽  
Sprague Dawley ◽  
Micro Computed Tomography ◽  
Model Cell

Replacement and inflammatory resorption are serious complications associated with the delayed replantation of avulsed teeth. In this study, we aimed to assess whether deferoxamine (DFO) can suppress inflammation and osteoclastogenesis in vitro and attenuate inflammation and bone resorption in a replanted rat tooth model. Cell viability and inflammation were evaluated in RAW264.7 cells. Osteoclastogenesis was confirmed by tartrate-resistant acid phosphatase staining, reactive oxygen species (ROS) measurement, and quantitative reverse transcriptase–polymerase chain reaction in teeth exposed to different concentrations of DFO. In vivo, molars of 31 six-week-old male Sprague–Dawley rats were extracted and stored in saline (n = 10) or DFO solution (n = 21) before replantation. Micro-computed tomography (micro-CT) imaging and histological analysis were performed to evaluate inflammation and root and alveolar bone resorption. DFO downregulated the genes related to inflammation and osteoclastogenesis. DFO also reduced ROS production and regulated specific pathways. Furthermore, the results of the micro-CT and histological analyses provided evidence of the decrease in inflammation and hard tissue resorption in the DFO group. Overall, these results suggest that DFO reduces inflammation and osteoclastogenesis in a tooth replantation model, and thus, it has to be further investigated as a root surface treatment option for an avulsed tooth.

Observation of the Pulp Chamber of Maxillary First Premolars: A Micro-computed Tomographic Study

2020 ◽  
Vol 16 (3) ◽  
pp. 224-230
Author(s):  
Gozde Serindere ◽  
Ceren Aktuna Belgin ◽  
Kaan Orhan
Keyword(s):  
Root Canal ◽  
Age Groups ◽  
Slice Thickness ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Pulp Chamber ◽  
Anatomical Structures ◽  
Computed Tomographic ◽  
The Mean ◽  
Chamber Floor

Background: There are a few studies about the evaluation of maxillary first premolars internal structure with micro-computed tomography (micro-CT). The aim of this study was to assess morphological features of the pulp chamber in maxillary first premolar teeth using micro- CT. Methods: Extracted 15 maxillary first premolar teeth were selected from the patients who were in different age groups. The distance between the pulp orifices, the diameter of the pulp and the width of the pulp chamber floor were measured on the micro-CT images with the slice thickness of 13.6 µm. The number of root canal orifices and the presence of isthmus were evaluated. Results: The mean diameter of orifices was 0.73 mm on the buccal side while it was 0.61 mm on palatinal side. The mean distance between pulp orifices was 2.84 mm. The mean angle between pulp orifices was -21.53°. The mean height of pulp orifices on the buccal side was 4.32 mm while the mean height of pulp orifices on the palatinal side was 3.56 mm. The most observed shape of root canal orifices was flattened ribbon. No isthmus was found in specimens. Conclusion: Minor anatomical structures can be evaluated in more detail with micro-CT. The observation of the pulp cavity was analyzed using micro-CT.

scholarly journals Lipopolysaccharide-Trap-Fc, a Multifunctional Agent To Battle Gram-Negative Bacteria

2009 ◽  
Vol 77 (7) ◽  
pp. 2925-2931 ◽  
Author(s):  
Philipp Groß ◽  
Katharina Brandl ◽  
Christine Dierkes ◽  
Jürgen Schölmerich ◽  
Bernd Salzberger ◽  
...  
Keyword(s):  
Myeloid Differentiation ◽  
Gram Negative Bacteria ◽  
Bacterial Sepsis ◽  
Tlr Signaling ◽  
Monocytic Cells ◽  
Gram Negative ◽  
The Family ◽  
Myeloid Differentiation Factor ◽  
Lps Treatment

ABSTRACT The family of Toll-like receptors (TLRs) plays a pivotal role in host defense against pathogens. However, overstimulation of these receptors may lead to uncontrolled general inflammation and eventually to systemic organ dysfunction or failure. With the intent to control overwhelming inflammation during gram-negative bacterial sepsis, we constructed soluble fusion proteins of the lipopolysaccharide (LPS)-receptor complex to modulate TLR signaling in multiple ways. The extracellular domain of mouse TLR4 and mouse myeloid differentiation factor 2 (MD-2) fusions (LPS-Trap) were linked to human immunoglobulin G Fc domains (LPS-Trap-Fc). In addition to the ability to bind LPS or gram-negative bacteria and to inhibit interleukin-6 secretion of monocytic cells after LPS treatment, LPS-Trap-Fc was able to opsonize fluorescent Escherichia coli particles. This led to enhancement of phagocytosis by monocytic cells which was strictly dependent on the presence of the Fc region. Moreover, only LPS-Trap-Fc- and not LPS-Trap-coated bacteria were sensitized to complement killing. Therefore, LPS-Trap-Fc not only neutralizes LPS but also, after binding to bacteria, enhances phagocytosis and complement-mediated killing and could thus act as a multifunctional agent to fight gram-negative bacteria in vivo.

scholarly journals Longitudinal in vivo micro-CT-based approach allows spatio-temporal characterization of fracture healing patterns and assessment of biomaterials in mouse femur defect models

2020 ◽  
Author(s):  
Esther Wehrle ◽  
Duncan C Tourolle né Betts ◽  
Gisela A Kuhn ◽  
Erica Floreani ◽  
Malavika H Nambiar ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Healing Process ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Collagen Scaffolds ◽  
Non Union ◽  
Spatio Temporal ◽  
Large Bone

AbstractThorough preclinical evaluation of novel biomaterials for treatment of large bone defects is essential prior to clinical application. Using in vivo micro-computed tomography (micro-CT) and mouse femoral defect models with different defect sizes, we were able to detect spatio-temporal healing patterns indicative of physiological and impaired healing in three defect sub-volumes and the adjacent cortex. The time-lapsed in vivo micro-CT-based approach was then applied to evaluate the bone regeneration potential of biomaterials using collagen and BMP-2 as test materials. Both collagen and BMP-2 treatment led to distinct changes in bone turnover in the different healing phases. Despite increased periosteal bone formation, 87.5% of the defects treated with collagen scaffolds resulted in non-unions. Additional BMP-2 application significantly accelerated the healing process and increased the union rate to 100%. This study further shows potential of time-lapsed in vivo micro-CT for capturing spatio-temporal deviations preceding non-union formation and how this can be prevented by application of biomaterials.This study therefore supports the application of longitudinal in vivo micro-CT for discrimination of normal and disturbed healing patterns and for the spatio-temporal characterization of the bone regeneration capacity of biomaterials.

scholarly journals The Importance of Routine Quality Control For Reproducible Pulmonary Measurements By in Vivo Micro-CT

2022 ◽  
Author(s):  
Martina Mambrini ◽  
Laura Mecozzi ◽  
Erica Ferrini ◽  
Ludovica Leo ◽  
Davide Bernardi ◽  
...  
Keyword(s):  
Disease Progression ◽  
Lung Diseases ◽  
Drug Efficacy ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Efficacy Evaluation ◽  
Lung Density ◽  
Before And After ◽  
The Impact

Abstract Micro-Computed Tomography (CT) imaging provides densitometric and functional assessment of lung diseases in animal models, playing a key role either in understanding disease progression or in drug discovery studies.The generation of reliable and reproducible experimental data is strictly dependent on a system’s stability. Quality Controls (QC) are essential to monitor micro-CT performance but, although QC procedures are standardized and routinely employed in clinical practice, detailed guidelines for preclinical imaging are lacking. In this work, we propose a routine QC protocol for in vivo micro-CT, based on three commercial phantoms. To investigate the impact of a detected scanner drift on image post-processing, a retrospective analysis using twenty-two healthy mice was performed and lung density histograms used to compare the Area Under Curve (AUC), the skewness and the kurtosis before and after the drift. As expected, statistically significant differences were found for all the selected parameters [AUC: 532 ± 31 vs. 420 ± 38 (p < 0.001); skewness: 2.3 ± 0.1 vs. 2.5 ± 0.1 (p < 0.001) and kurtosis: 4.2 ± 0.3 vs. 5.1 ± 0.5 (p < 0.001)], confirming the importance of the designed QC procedure to obtain a reliable longitudinal quantification of disease progression and drug efficacy evaluation.

scholarly journals PEG-modified gadolinium nanoparticles as contrast agents for in vivo micro-CT

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Charmainne Cruje ◽  
P. Joy Dunmore-Buyze ◽  
Eric Grolman ◽  
David W. Holdsworth ◽  
Elizabeth R. Gillies ◽  
...  
Keyword(s):  
Contrast Agent ◽  
Contrast Agents ◽  
Soft Tissues ◽  
Three Dimensional ◽  
Blood Pool ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Poly Ethylene

AbstractVascular research is largely performed in rodents with the goal of developing treatments for human disease. Micro-computed tomography (micro-CT) provides non-destructive three-dimensional imaging that can be used to study the vasculature of rodents. However, to distinguish vasculature from other soft tissues, long-circulating contrast agents are required. In this study, we demonstrated that poly(ethylene glycol) (PEG)-coated gadolinium nanoparticles can be used as a vascular contrast agent in micro-CT. The coated particles could be lyophilized and then redispersed in an aqueous solution to achieve 100 mg/mL of gadolinium. After an intravenous injection of the contrast agent into mice, micro-CT scans showed blood pool contrast enhancements of at least 200 HU for 30 min. Imaging and quantitative analysis of gadolinium in tissues showed the presence of contrast agent in clearance organs including the liver and spleen and very low amounts in other organs. In vitro cell culture experiments, subcutaneous injections, and analysis of mouse body weight suggested that the agents exhibited low toxicity. Histological analysis of tissues 5 days after injection of the contrast agent showed cytotoxicity in the spleen, but no abnormalities were observed in the liver, lungs, kidneys, and bladder.

scholarly journals MyD88, but Not Toll-Like Receptors 4 and 2, Is Required for Efficient Clearance of Brucella abortus

2005 ◽  
Vol 73 (8) ◽  
pp. 5137-5143 ◽  
Author(s):  
David S. Weiss ◽  
Kiyoshi Takeda ◽  
Shizuo Akira ◽  
Arturo Zychlinsky ◽  
Edgardo Moreno
Keyword(s):  
Myeloid Differentiation ◽  
Toll Like Receptor ◽  
Immunostimulatory Activity ◽  
Toll Like Receptor 4 ◽  
Gram Negative ◽  
Macrophage Response ◽  
Tlr4 Activation ◽  
Myeloid Differentiation Factor ◽  
Kinetics Of

ABSTRACT It is not clear how the host initially recognizes and responds to infection by gram-negative pathogenic Brucella spp. It was previously shown (D. S. Weiss, B. Raupach, K. Takeda, S. Akira, and A. Zychlinsky, J. Immunol. 172:4463-4469, 2004) that the early macrophage response against gram-negative bacteria is mediated by Toll-like receptor 4 (TLR4), which signals in response to lipopolysaccharide (LPS). Brucella, however, has a noncanonical LPS which does not have potent immunostimulatory activity. We evaluated the kinetics of TLR4 activation and the cytokine response in murine macrophages after Brucella infection. We found that during infection of macrophages, Brucella avoids activation of TLR4 at 6 h but activates TLR4, TLR2, and myeloid differentiation factor 88 (MyD88) at 24 h postinfection. Interestingly, even though its activation is delayed, MyD88 is important for host defense against Brucella infection in vivo, since MyD88−/− mice do not clear the bacteria as efficiently as wild-type, TLR4−/−, TLR2−/−, or TLR4/TLR2−/− mice.

scholarly journals Role of NOD2 and RIP2 in host–microbe interactions with Gram-negative bacteria: insights from the periodontal disease model

2016 ◽  
Vol 22 (8) ◽  
pp. 598-611 ◽  
Author(s):  
Joao AC Souza ◽  
Marcell C Medeiros ◽  
Fernanda RG Rocha ◽  
Sabrina G de Aquino ◽  
Mario J Ávila-Campos ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Osteoclast Differentiation ◽  
Disease Model ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Macrophage Response ◽  
Chronic Inflammatory Condition ◽  
Host Microbe Interactions

NOD2 is a member of the NLR family of proteins that participate in the activation of the innate immune response. RIP2 is a downstream kinase activated by both NOD1 and NOD2. There is scarcity of information regarding the relevance of NOD2 in periodontitis, a chronic inflammatory condition characterized by inflammatory bone resorption. We used NOD2-KO and RIP2-KO mice in a model of microbial-induced periodontitis. Heat-killed Aggregatibacter actinomycetemcomitans was injected in the gingival tissues three times/wk for 4 wk. Bone resorption was assessed by μCT analysis; osteoclasts were identified by immunohistochemical staining for TRAP and inflammation was assessed using a severity score system in H/E-stained sections. In vitro studies using primary macrophages assessed the response macrophages using qPCR-based array and multi-ligand ELISA. Bone resorption and osteoclastogenesis were significantly reduced in NOD2-KO mice. Severity of inflammation was not affected. qPCR-focused arrays and multi-ligand ELISA showed that expression of pro-inflammatory mediators was reduced in NOD2- and RIP2-deficient cells. RANKL-induced osteoclastogenesis was impaired in NOD2- and RIP2-deficient macrophages. We conclude that NOD2 is important for osteoclast differentiation and inflammatory bone resorption in vivo and also for the macrophage response to Gram-negative bacteria.

scholarly journals The Characteristics of Vascular Growth in VX2 Tumor Measured by MRI and Micro-CT

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
X.-L. Qi ◽  
J. Liu ◽  
P. N. Burns ◽  
G. A. Wright
Keyword(s):  
Volume Fraction ◽  
Tumor Model ◽  
Response To Therapy ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Tumor Vascularity ◽  
Vx2 Tumor ◽  
Relative Blood Volume

Blood supply is crucial for rapid growth of a malignant tumor; medical imaging can play an important role in evaluating the vascular characterstics of tumors. Magnetic resonance imaging (MRI) and micro-computed tomography (CT) are able to detect tumors and measure blood volumes of microcirculation in tissue. In this study, we used MR imaging and micro-CT to assess the microcirculation in a VX2 tumor model in rabbits. MRI characterization was performed using the intravascular contrast agent Clariscan (NC100150-Injection); micro-CT with Microfil was used to directly depict blood vessels with diameters as low as 17 um in tissue. Relative blood volume fraction (rBVF) in the tumor rim and blood vessel density (rBVD) over the whole tumor was calculated using the two imaging methods. Our study indicates that rBVF is negatively related to the volume of the tumor measured by ultrasound (R=0.90). rBVF in the tissue of a VX2 tumor measured by MRIin vivowas qualitatively consistent with the rBVD demonstrated by micro-CTin vitro(R=0.97). The good correlation between the two methods indicates that MRI studies are potentially valuable for assessing characteristics or tumor vascularity and for assessing response to therapy noninvasively.

scholarly journals Lysophosphatidic Acid Analogue rather than Lysophosphatidic Acid Promoted the Bone Formation In Vivo

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Zi-Li Yu ◽  
Bin-Fang Jiao ◽  
Zu-Bing Li
Keyword(s):  
Bone Formation ◽  
Lysophosphatidic Acid ◽  
Histological Analysis ◽  
Alizarin Red S ◽  
Porous Scaffolds ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Alizarin Red ◽  
Lipid Molecule

Lysophosphatidic acid (LPA), a bioactive lipid molecule, has recently emerged as physiological and pathophysiological regulator in skeletal biology. Here we evaluate the effects of LPA on bone formation in vivo in murine femoral critical defect model. Primary femoral osteoblasts were isolated and treated with osteogenic induction conditional media supplemented with 20 μM LPA or LPA analogue. Mineralized nodules were visualized by Alizarin Red S staining. Forty-five C57BL/6 mice underwent unilateral osteotomy. The femoral osteotomy gap was filled with porous scaffolds of degradable chitosan/beta-tricalcium phosphate containing PBS, LPA, or LPA analogue. 2, 5, and 10 weeks after surgery, mice were sacrificed and femurs were harvested and prepared for Micro-Computed Tomography (Micro-CT) and histological analysis. Alizarin Red S staining showed that LPA and LPA analogue significantly enhanced the mineral deposition in osteoblasts. Micro-CT 3D reconstruction images and HE staining revealed that significantly more newly formed bone in osteotomy was treated with LPA analogue when compared to control and LPA group, which was verified by histological analysis and biomechanical characterization testing. In summary, our study demonstrated that although LPA promotes mineralized matrix formation in vitro, the locally administrated LPA was not effective in promoting bone formation in vivo. And bone formation was enhanced by LPA analogue, administrated locally in vivo. LPA analogue was a potent stimulating factor for bone formation in vivo due to its excellent stability.

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