scholarly journals Reconstruction of Cochlea Based on Micro-CT and Histological Images of the Human Inner Ear

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Christos Bellos ◽  
George Rigas ◽  
Ioannis F. Spiridon ◽  
Athanasios Bibas ◽  
Dimitra Iliopoulou ◽  
...  
Keyword(s):  
Mathematical Modelling ◽  
Inner Ear ◽  
Basilar Membrane ◽  
Three Dimensional ◽  
Surgical Excision ◽  
Multiscale Model ◽  
Normal Function ◽  
Spiral Ligament ◽  
Micro Ct ◽  
Histological Images

The study of the normal function and pathology of the inner ear has unique difficulties as it is inaccessible during life and, so, conventional techniques of pathologic studies such as biopsy and surgical excision are not feasible, without further impairing function. Mathematical modelling is therefore particularly attractive as a tool in researching the cochlea and its pathology. The first step towards efficient mathematical modelling is the reconstruction of an accurate three dimensional (3D) model of the cochlea that will be presented in this paper. The high quality of the histological images is being exploited in order to extract several sections of the cochlea that are not visible on the micro-CT (mCT) images (i.e., scala media, spiral ligament, and organ of Corti) as well as other important sections (i.e., basilar membrane, Reissner membrane, scala vestibule, and scala tympani). The reconstructed model is being projected in the centerline of the coiled cochlea, extracted from mCT images, and represented in the 3D space. The reconstruction activities are part of the SIFEM project, which will result in the delivery of an infrastructure, semantically interlinking various tools and libraries (i.e., segmentation, reconstruction, and visualization tools) with the clinical knowledge, which is represented by existing data, towards the delivery of a robust multiscale model of the inner ear.

Immunolocalization of aquaporin CHIP in the guinea pig inner ear

1995 ◽  
Vol 269 (6) ◽  
pp. C1450-C1456 ◽  
Author(s):  
K. M. Stankovic ◽  
J. C. Adams ◽  
D. Brown
Keyword(s):  
Inner Ear ◽  
Basilar Membrane ◽  
Polyclonal Antibodies ◽  
Close Association ◽  
Water Channel ◽  
Normal Function ◽  
Oval Window ◽  
Spiral Ligament ◽  
Bony Labyrinth ◽  
Spiral Ligament Fibrocytes

Aquaporin CHIP (AQP-CHIP) is a water channel protein previously identified in red blood cells and water transporting epithelia. The inner ear is an organ of hearing and balance whose normal function depends critically on maintenance of fluid homeostasis. In this study, AQP-CHIP, or a close homologue, was found in specific cells of the inner ear, as assessed by immunocytochemistry with the use of affinity-purified polyclonal antibodies against AQP-CHIP.AQP-CHIP was predominantly found in fibrocytes in close association with bone, including most of the cells lining the bony labyrinth and in fibrocytes lining the endolymphatic duct and sac. AQP-CHIP-positive cells not directly apposing bone include cells under the basilar membrane, some type III fibrocytes of the spiral ligament, fibrocytes of the spiral limbus, and the trabecular perilymphatic tissue extending from the membranous to the bony labyrinth. AQP-CHIP was also found in the periosteum of the middle ear and cranial bones, as well as in chondrocytes of the oval window and stapes. The distribution of AQP-CHIP in the inner ear suggests that AQP-CHIP may have special significance for maintenance of bone and the basilar membrane, and for function of the spiral ligament.

The localization and specificity of guinea pig inner ear antigenic epitopes

1995 ◽  
Vol 109 (1) ◽  
pp. 19-23 ◽  
Author(s):  
Ming-Yu Cao ◽  
Michel Gersdorff ◽  
Naïma Deggouj ◽  
Jean-Paul Tomasi
Keyword(s):  
Guinea Pig ◽  
Inner Ear ◽  
Basilar Membrane ◽  
Stria Vascularis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Spiral Ligament ◽  
Antigenic Epitope ◽  
Acoustic Nerve ◽  
The Brain ◽  
Antigenic Epitopes

AbstractIn this study, we investigated the relative localization of some antigenic epitopes in the inner ear. The inner ear protein antigens were extracted from various parts of the guinea pig inner ear. Brain, kidney, lung, heart and liver extracts were also obtained. We found by SDS-polyacrylamide gel electrophoresis that total inner ear extracts separated into three high concentration polypeptide bands with molecular weights of approximately 30, 42, 58 kd and three low density bands of 20,25 and 35 kd. The 30 kd band was found mainly in the extract of the spiral ganglion and the acoustic nerve in the modiolus. The 42 and 58 kd bands were detected in the extract of the spiral ligament and the stria vascularis. The Organ of Corti and the basilar membrane extract gave rise to three bands of 30,42 and 58 kd. Twenty-eight of the 75 sera from patients with inner ear disease reacted with the 30 and 58 kd bands of the inner ear protein extracts by immunoblotting. Sixteen of these 28 positive sera were then used to probe immunoblots of the brain, kidney, lung, heart and liver extracts. The 58 kd band was also found in protein extracts of the brain, the lung and the liver. This study suggests that the 30 kd antigenic epitope may be mainly related to the acoustic nerve and that the 58 kd antigenic epitope is not cochlear specific.

scholarly journals Targeted Deletion of Loxl3 by Col2a1-Cre Leads to Progressive Hearing Loss

2021 ◽  
Vol 9 ◽  
Author(s):  
Ziyi Liu ◽  
Xinfeng Bai ◽  
Peifeng Wan ◽  
Fan Mo ◽  
Ge Chen ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Inner Ear ◽  
Essential Role ◽  
Basilar Membrane ◽  
Inflammatory Responses ◽  
Spiral Ganglion ◽  
Spiral Ligament ◽  
Progressive Hearing Loss ◽  
Secondary Degeneration ◽  
Ganglion Neurons

Collagens are major constituents of the extracellular matrix (ECM) that play an essential role in the structure of the inner ear and provide elasticity and rigidity when the signals of sound are received and transformed into electrical signals. LOXL3 is a member of the lysyl oxidase (LOX) family that are copper-dependent amine oxidases, generating covalent cross-links to stabilize polymeric elastin and collagen fibers in the ECM. Biallelic missense variant of LOXL3 was found in Stickler syndrome with mild conductive hearing loss. However, available information regarding the specific roles of LOXL3 in auditory function is limited. In this study, we showed that the Col2a1-Cre-mediated ablation of Loxl3 in the inner ear can cause progressive hearing loss, degeneration of hair cells and secondary degeneration of spiral ganglion neurons. The abnormal distribution of type II collagen in the spiral ligament and increased inflammatory responses were also found in Col2a1–Loxl3–/– mice. Amino oxidase activity exerts an effect on collagen; thus, Loxl3 deficiency was expected to result in the instability of collagen in the spiral ligament and the basilar membrane, which may interfere with the mechanical properties of the organ of Corti and induce the inflammatory responses that are responsible for the hearing loss. Overall, our findings suggest that Loxl3 may play an essential role in maintaining hearing function.

scholarly journals A Microcomputed Tomographic Evaluation of Root Canal Morphology of Maxillary Second Premolars in a Pakistani Cohort

2021 ◽  
Vol 11 (11) ◽  
pp. 5086
Author(s):  
Mazen F. Alkahtany ◽  
Saqib Ali ◽  
Abdul Khabeer ◽  
Shafqat A. Shah ◽  
Khalid H. Almadi ◽  
...  
Keyword(s):  
Root Canal ◽  
Three Dimensional ◽  
Ct Scanning ◽  
Micro Ct ◽  
Single Root ◽  
Root Canal Morphology ◽  
Spss Software ◽  
Variable Morphology ◽  
Canal Morphology

This study aimed to investigate variations in the root canal morphology of maxillary second premolar (MSP) teeth using microcomputed tomography (micro-CT). Sixty (N = 60) human extracted MSPs were collected and prepared for micro-CT scanning. The duration for scanning a single sample ranged between 30 and 40 min and a three-dimensional (3-D) image was obtained for all the MSPs. The images were evaluated by a single observer who recorded the canal morphology type, number of roots, canal orifices, apical foramina(s), apical delta(s), and accessory canals. The root canal configuration was categorized in agreement with Vertucci’s classification, and any configuration not in agreement with Vertucci’s classification was reported as an “additional canal configuration”. Descriptive statistics (such as mean percentages) were calculated using SPSS software. The most common types agreeing with Vertucci’s classification (in order of highest to lowest incidence) were types I, III, V, VII, II, and VI. The teeth also exhibited four additional configurations that were different from Vertucci’s classification: types 2-3, 1-2-3, 2-1-2-1, and 1-2-1-3. A single root was found in 96.7% and the majority of the samples demonstrated two canals (73.3%). Further, 80% of the teeth showed one canal orifice. The number of apical foramina’s in the teeth was variable, with 56.7% having solitary apical foramen. The accessory canal was found in 33.3%, and apical delta was found in only 20% of the samples. Variable morphology of the MSPs was detected in our study. The canal configuration most prevalent was type 1; however, the results also revealed some additional canal types.

scholarly journals An In Vivo 3D Micro-CT Evaluation of Tooth Movement After the Application of Different Force Magnitudes in Rat Molar

2009 ◽  
Vol 79 (4) ◽  
pp. 703-714 ◽  
Author(s):  
Carmen Gonzales ◽  
Hitoshi Hotokezaka ◽  
Yoshinori Arai ◽  
Tadashi Ninomiya ◽  
Junya Tominaga ◽  
...  
Keyword(s):  
Tooth Movement ◽  
Three Dimensional ◽  
Element Model ◽  
Longitudinal Change ◽  
Micro Ct ◽  
Linear Measurements ◽  
Center Of Rotation ◽  
Ct Evaluation ◽  
Space Width

Abstract Objective: To investigate the precise longitudinal change in the periodontal ligament (PDL) space width and three-dimensional tooth movement with continuous-force magnitudes in living rats. Materials and Methods: Using nickel-titanium closed-coil springs for 28 days, 10-, 25-, 50-, and 100-g mesial force was applied to the maxillary left first molars. Micro-CT was taken in the same rat at 0, 1, 2, 3, 10, 14, and 28 days. The width of the PDL was measured in the pressure and tension sides from 0 to 3 days. Angular and linear measurements were used to evaluate molar position at day 0, 10, 14, and 28. The finite element model (FEM) was constructed to evaluate the initial stress distribution, molar displacement, and center of rotation of the molar. Results: The initial evaluation of PDL width showed no statistical differences among different force magnitudes. Tooth movement was registered 1 hour after force application and gradually increased with time. From day 10, greater tooth movement was observed when 10 g of force was applied. The FEM showed that the center of rotation in the molar is located in the center of five roots at the apical third of the molar roots. Conclusion: The rat's molar movement mainly consists of mesial tipping, extrusion of distal roots, intrusion of mesial root, palatal inclination, and mesial rotation. Although the initial tooth movement after the application of different force magnitudes until day 3 was not remarkably different, 10 g of force produced more tooth movement compared with heavier forces at day 28.

Early changes in coronary artery wall structure detected by microcomputed tomography in experimental hypercholesterolemia

2007 ◽  
Vol 293 (3) ◽  
pp. H1997-H2003 ◽  
Author(s):  
Xiang-Yang Zhu ◽  
Michael D. Bentley ◽  
Alejandro R. Chade ◽  
Erik L. Ritman ◽  
Amir Lerman ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Coronary Artery ◽  
Growth Factor ◽  
Three Dimensional ◽  
Wall Structure ◽  
Vascular Endothelial ◽  
Micro Ct ◽  
Artery Wall ◽  
Coronary Artery Wall ◽  
Endothelial Growth Factor

Changes in the structure of the artery wall commence shortly after exposure to cardiovascular risk factors, such as hypercholesterolemia (HC), but may be difficult to detect. The ability to study vascular wall structure could be helpful in evaluation of the factors that instigate atherosclerosis and its pathomechanisms. The present study tested the hypothesis that early morphological changes in coronary arteries of hypercholesterolemic (HC) pigs can be detected using the novel X-ray contrast agent OsO4 and three-dimensional micro-computed tomography (CT). Two groups of pigs were studied after they were fed a normal or an HC (2% cholesterol) diet for 12 wk. Hearts were harvested, coronary arteries were injected with 1% OsO4 solution, and cardiac samples (6-μm-thick) were scanned by micro-CT. Layers of the epicardial coronary artery wall, early lesions, and perivascular OsO4 accumulation were determined. Leakage of OsO4 from myocardial microvessels was used to assess vascular permeability, which was correlated with immunoreactivity of vascular endothelial growth factor in corresponding histological cross sections. OsO4 enhanced the visualization of coronary artery wall layers and facilitated detection of early lesions in HC in longitudinal tomographic sections of vascular segments. Increased density of perivascular OsO4 in HC was correlated with increased vascular endothelial growth factor expression and suggested increased microvascular permeability. The use of OsO4 as a contrast agent in micro-CT allows three-dimensional visualization of coronary artery wall structure, early lesion formation, and changes in vascular permeability. Therefore, this technique can be a useful tool in atherosclerosis research.

scholarly journals Micro-CT data of early physiological cancellous bone formation in the lumbar spine of female C57BL/6 mice

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Michael Zenzes ◽  
Paul Zaslansky
Keyword(s):  
Cancellous Bone ◽  
Structural Changes ◽  
Bone Growth ◽  
Post Partum ◽  
Three Dimensional ◽  
Lumbar Vertebra ◽  
Tissue Growth ◽  
Micro Ct ◽  
Mineral Density ◽  
Ct Data

AbstractMicro-CT provides critical data for musculoskeletal research, yielding three-dimensional datasets containing distributions of mineral density. Using high-resolution scans, we quantified changes in the fine architecture of bone in the spine of young mice. This data is made available as a reference to physiological cancellous bone growth. The scans (n = 19) depict the extensive structural changes typical for female C57BL/6 mice pups, aged 1-, 3-, 7-, 10- and 14-days post-partum, as they attain the mature geometry. We reveal the micro-morphology down to individual trabeculae in the spine that follow phases of mineral-tissue rearrangement in the growing lumbar vertebra on a micrometer length scale. Phantom data is provided to facilitate mineral density calibration. Conventional histomorphometry matched with our micro-CT data on selected samples confirms the validity and accuracy of our 3D scans. The data may thus serve as a reference for modeling normal bone growth and can be used to benchmark other experiments assessing the effects of biomaterials, tissue growth, healing, and regeneration.

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