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 Treatment of HIV-associated facial lipoatrophy: impact on infection progression assessed by viral load and CD4 count

2013 ◽  
Vol 88 (4) ◽  
pp. 570-577 ◽  
Author(s):  
Flávia Machado Gonçalves Soares ◽  
Izelda Maria Carvalho Costa
Keyword(s):  
Viral Load ◽  
Disease Progression ◽  
Statistical Significance ◽  
Undetectable Viral Load ◽  
Fat Distribution ◽  
Cd4 Count ◽  
Before And After ◽  
Facial Lipoatrophy ◽  
A Prospective Study ◽  
The Impact

BACKGROUND: HIV/AIDS-Associated Lipodystrophy Syndrome includes changes in body fat distribution, with or without metabolic changes. The loss of fat from the face, called facial lipoatrophy, is one of the most stigmatizing signs of the syndrome.OBJECTIVES:To evaluate the effect of FL treatment using polymethylmethacrylate (PMMA) implants on disease progression, assessed by viral load and CD4 cell count.METHODS: This was a prospective study of 44 patients treated from July 2009 to December 2010. Male and female patients, aged over 18 years, with clinically detectable FL and who had never been treated were included in the study. PMMA implantation was done to fill atrophic areas. Laboratory tests were conducted to measure viral load and CD4 count before and after treatment.RESULTS: Of the 44 patients, 72.72% were male and 27.27% female, mean age of 44.38 years. Before treatment, 82% of patients had undetectable viral load, which increased to 88.6% after treatment, but without statistical significance (p = 0.67). CD4 count before treatment ranged from 209 to 1293, averaging 493.97. After treatment, the average increased to 548.61. The increase in CD4 count after treatment was statistically significant with p = 0.02.CONCLUSION: The treatment of FL with PMMA implants showed a statistically significant increase in CD4 count after treatment, revealing the impact of FL treatment on disease progression. Viral load before and after treatment did not vary significantly.

scholarly journals Effects of pre-extraction intermittent PTH administration on extraction socket healing in bisphosphonate administered ovariectomized rats

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jae-Young Kim ◽  
Hyo-Won Jang ◽  
Jung-In Kim ◽  
In-Ho Cha
Keyword(s):  
Tooth Extraction ◽  
Bisphosphonate Therapy ◽  
Ovariectomized Rats ◽  
Control Group ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Extraction Socket ◽  
Before And After ◽  
Socket Healing ◽  
Positive Effect

AbstractThe purpose of this study was to investigate the effect of administering intermittent parathyroid hormone (iPTH) before tooth extraction versus after tooth extraction on the risk of developing MRONJ in experimental animal model. Twenty-five ovariectomized rats received 6 weeks of bisphosphonate therapy. They were classified into 3 groups, based on the timing of the medication, as Control, Pre-PTH and Post-PTH groups. For Control group, normal saline was administered before and after tooth extraction. iPTH was administered during 4 weeks before tooth extraction for Pre-PTH group and after tooth extraction for Post-PTH group. The animals were euthanized 8 weeks after tooth extraction. Macroscopic, histological, micro-computed tomography (micro-CT), and histomorphometric examinations were conducted. The incidences of impaired healing were 11.11% both in Pre-PTH and Post-PTH groups, which was lower than the Control group (42.86%). Bone healing in the extraction socket, based on micro-CT and histomorphometry evaluations, was best in Post-PTH and worst in Control group. The Pre-PTH group showed moderate healing pattern. Despite of limitations in this study, the authors identified Pre-PTH group seems to have positive effect on extraction socket healing. With regard to timing, administering iPTH after tooth extraction was superior to applying it before tooth extraction.

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 Influence of the calcium hydroxide paste vehicle on penetration into lateral canals

2018 ◽  
Vol 21 (3) ◽  
pp. 282
Author(s):  
Amanda Sousa Vidal ◽  
Daniele Aparecida Leão ◽  
Fernanda Mota Guimarães ◽  
Mariana Oliveira Gonçalves ◽  
Raissa Freitas Pinheiro ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Calcium Hydroxide ◽  
Propylene Glycol ◽  
Group Analysis ◽  
Distilled Water ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Respective Group ◽  
Before And After

<p><strong>Objective: </strong>The aim of this study was to use Micro computed tomography (micro-CT) to evaluate the influence of the type of vehicle associated with calcium hydroxide on its ability to penetrate simulated lateral canals. <strong>Materials and methods:</strong> 30 acrylic blocks with simulated lateral canals comprising apical, middle and cervical thirds were used in the <em>in vitro</em> study. The blocks were divided into 3 groups (n = 10) according to the type of vehicle used (chlorhexidine, distilled water and propylene glycol) in the calcium hydroxide slurry, which was inserted in the respective group of simulated canals with a K# 30 file and then agitated with an ultrasonic tip. The blocks were scanned by micro-computed tomography (micro-CT) before and after insertion of the medication. The images obtained were reconstructed and analyzed to obtain the initial volume of lateral canals and the volume of medication that penetrated into them. <strong>Results:</strong> In the intragroup analysis, both distilled water and chlorhexidine 2% were observed to present statistical difference in all thirds of the canal. Propylene glycol showed no intragroup difference. In the inter-group analysis, the propylene glycol paste presented higher values of penetration into the simulated lateral canals than the other groups (p &lt;0.05). <strong>Conclusion:</strong> Propylene glycol used as vehicle of the calcium hydroxide paste provided better penetration results in simulated lateral canals.</p>

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 Stochastic Model for In-Host HIV Dynamics with Therapeutic Intervention

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Waema R. Mbogo ◽  
Livingstone S. Luboobi ◽  
John W. Odhiambo
Keyword(s):  
Therapeutic Intervention ◽  
Probability Generating Function ◽  
Simulated Data ◽  
Drug Efficacy ◽  
Undetectable Viral Load ◽  
Stochastic Approach ◽  
Intracellular Delay ◽  
Before And After ◽  
The Moment

Untangling the dynamics between HIV and CD4 cellular populations and molecular interactions can be used to investigate the effective points of interventions in the HIV life cycle. With that in mind, we propose and show the usefulness of a stochastic approach towards modeling HIV and CD4 cells’ dynamics in vivo by obtaining probability generating function, the moment structures of the healthy CD4 cell and the virus particles at any time t, and the probability of HIV clearance. The unique feature is that both therapy and the intracellular delay are incorporated into the model. Our analysis shows that, when it is assumed that the drug is not completely effective as is the case of HIV in vivo, the probability of HIV clearance depends on two factors: the combination of drug efficacy and length of the intracellular delay and also the education of the infected patients. Comparing simulated data before and after treatment indicates the importance of combined therapeutic intervention and intracellular delay in having low, undetectable viral load in HIV-infected person.

scholarly journals Microtomographic Evaluation of Canal Centralization and Dentine Removal after Canal Preparation with Two Rotary Systems: HyFlex EDM and ProTaper Next

2022 ◽  
Author(s):  
Vivian Ronquete ◽  
Alexandre Sigrist de Martin ◽  
Karin Zuim ◽  
Thais Machado de Carvalho Coutinho ◽  
Eduardo Fagury Videira Marceliano ◽  
...  
Keyword(s):  
Root Canal ◽  
Root Diameter ◽  
Micro Ct ◽  
Micro Computed Tomography ◽  
Type Iv ◽  
Canal Diameter ◽  
Mandibular Molar ◽  
Apical Transportation ◽  
Significant Difference ◽  
Before And After

Abstract Objective This study compared the ProTaper Next (PTN; Dentsply Sirona, Tulsa, Oklahoma, United States) and HyFlex EDM (HEDM; Coltene/Whaledent AG, Alstätten, Switzerland) systems using micro–computed tomography (CT). Materials and Methods Twenty-one mesial roots classified as Vertucci's type IV from extracted mandibular first molars with curvatures between 20 and 40 degrees were selected. The teeth were scanned using a micro-CT before and after root canal preparation by both systems, applied to the same root, in alternating canals. The following parameters were analyzed: canal centering, apical transportation, root canal diameter/root diameter. Results No statistically significant differences between both systems were observed for any of the assessed morphological parameters (p > 0.05). All canals presented diameter enlargement of more than 40% in relation to root diameter in the cervical and middle segments. No statistically significant difference was noted between the HEDM and PTN groups. The wear percentage for the HEDM group in the cervical and middle thirds were 49.66 ± 8.65 and 46.48 ± 14.29, respectively, and 51.02 ± 11.81 and 45.48 ± 10.79 for the PTN group, respectively. Conclusion Both systems displayed similar mandibular molar mesial canals preparation, with no differences noted for any of the assessed parameters. Both groups showed increased canal diameter in the cervical and middle thirds by more than 40%.

scholarly journals Assessment of Corneal subbasal nerve plexus using confocal in vivo microscopy in patients with pseudoexfoliation syndrome after phacoemulsification

2018 ◽  
Vol 11 (2) ◽  
pp. 13-18 ◽  
Author(s):  
Vitaly V. Potyomkin ◽  
Tatyana S. Varganova ◽  
Irina V. Terehova ◽  
Elena V. Ageeva
Keyword(s):  
Cataract Surgery ◽  
Main Group ◽  
Nerve Plexus ◽  
Pseudoexfoliation Syndrome ◽  
Control Group ◽  
In Vivo Microscopy ◽  
Before And After ◽  
The Impact ◽  
Subbasal Nerve Plexus

Phacoemulsification (PE) is the leading method of cataract surgery. Purpose. To assess the impact of PE on corneal subbasal nerve plexus in patients with pseudoexfoliation syndrome (PEX) using confocal in vivo microscopy. Methods. 42 patients (42 eyes) were enrolled in the study. The main group consisted of 24 patients (24 eyes) with PEX syndrome, and 18 patients (18 eyes) without it composed the control group. Confocal in vivo microscopy was performed before and after PHACO. Results. In patients with PEX after PE, an increase in number of nerve branches and pellet-like structures in them were noticed (p < 0,05).

scholarly journals Effect of freezing on the microstructure of a highly decomposed peat material close to water saturation when used prior to X-ray micro computed tomography

2021 ◽  
Author(s):  
Hassan Al Majou ◽  
Ary Bruand ◽  
Olivier Rozembaum ◽  
Emmanuel Le Trong
Keyword(s):  
Computed Tomography ◽  
Pore Volume ◽  
Specific Volume ◽  
Water Saturation ◽  
Organic Matrix ◽  
Micro Computed Tomography ◽  
X Ray ◽  
Two Samples ◽  
Before And After ◽  
The Impact

Abstract. The modelling of peatland functioning, in particular the impact of anthropogenic warming and direct human disturbance on CO2, CH4 and N2O, requires detailed knowledge of the peat structure and of both water and gas flow with respect to the groundwater table level. To this end, freezing is nowadays increasingly used to obtain small size peat samples for X-ray micro computed tomography (X-ray μ-CT) as required by the need to increase the resolution of the 3D X-ray CT images of the peat structure recorded. The aim of this study was to analyze the structure of a peat material before and after freezing using X-ray μ-CT and to look for possible alterations in the structure by investigating looking at the air-filled porosity. A highly decomposed peat material close to water saturation was selected for study and collected between 25 and 40 cm depth. Two samples 4 × 4 × 7 cm3 in volume were analyzed before and after freezing using an X-ray μ-CT Nanotom 180NF (GE Phoenix X-ray, Wunstorf, Germany) with a 180 kV nanofocus X-ray tube and a digital detector array (2304 × 1152 pixels Hamamatsu detector). Results showed that the continuity and cross section of the air-filled tubular pores several hundreds to about one thousand micrometers in diameter were altered after freezing. Many much smaller air-filled pores not detected before freezing were also recorded after freezing with 470 and 474 pores higher than one voxel in volume (60 × 60 × 60 μm3 in volume each) before freezing, and 4792 and 4371 air-filled pores higher than one voxel in volume after freezing for the two samples studied. Detailed analysis showed that this increase resulted from a difference in the whole range of pore size studied and particularly from a dramatic increase in the number of air-filled pores ranging between 1 voxel (216 103 μm3) and 50 voxels (10.8 106 μm3) in volume. Theoretical calculation of the consequences of the increase in the specific volume of water by 8.7 % when it turns from liquid to solid because of freezing led to the creation of a pore volume in the organic matrix which remains saturated by water when returning to room temperature and consequently to the desaturation of the largest pores of the organic matrix as well as the finest tubular pores which were water-filled before freezing. These new air-filled pores are those measured after freezing using X-ray μ-CT and their volume is consistent with the one calculated theoretically. They correspond to small air-filled ovoid pores several voxels in volume to several dozen voxels in volume and to discontinuous air-filled fine tubular pores which were both detected after freezing. Finally, the increase in the specific volume of water because of freezing appears also be also responsible for the alteration of the already air-filled tubular pores before freezing as shown by the 3D binary images and the pore volume distribution.

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.

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