scholarly journals Use of OCT Angiography in Choroidal Melanocytic Tumors

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Juan J. Toledo ◽  
Mónica Asencio-Duran ◽  
Jesús R. García-Martinez ◽  
Alejandro López-Gaona
Keyword(s):  
New Technology ◽  
Choroidal Melanoma ◽  
General Description ◽  
Vascular Networks ◽  
Cross Sectional ◽  
Melanocytic Tumors ◽  
Choroidal Melanomas ◽  
Choroidal Nevus ◽  
Histopathological Studies

Objective. To describe OCTA findings in choroidal melanocytic tumors, especially the microcirculation patterns, and to try to correlate with the histopathological studies. Methods. Cross-sectional, comparative, observational study. 70 cases, including 55 choroidal nevi and 15 choroidal melanomas. Three different observers evaluated specific variables in the choriocapillaris layer on AOCT images and searched for images which described histopathologic vascular patterns, and also, a general description of the images was made. Complementary multi-imaging studies included EDI SD-OCT, color and autofluorescence fundus imaging, Doppler ultrasound, and indocyanine/fluorescein angiography. Main Results. Good quality studies were acquired in 80% of the cases, with kappa indexes 0.768–0.958. Nevus OCTA images were described mainly as hyperreflective (72.7%), whereas choroidal melanoma as iso/hyporeflective (62.5%). Avascular areas were found in 50.96% and in 33.3% of choroidal nevus and choroidal melanomas, respectively. A neovascular membrane was found only in cases of choroidal nevus (16.3%). Only in cases of choroidal melanomas, we found vascular loops (6.6%) or vascular networks (6.6%). Conclusion. OCTA is a promising new technology that can be used to study in vivo the differential characteristics of microcirculations between posterior segment melanocytic lesions. Today, larger studies are needed to corroborate these findings and to correlate it with malignancy.

Is optical coherence tomography angiography helpful in the differential diagnosis of choroidal nevus versus melanoma?

2019 ◽  
Vol 30 (4) ◽  
pp. 723-729 ◽  
Author(s):  
Claudia Garcia-Arumi Fuste ◽  
Federico Peralta Iturburu ◽  
Jose Garcia-Arumi
Keyword(s):  
Optical Coherence Tomography ◽  
Differential Diagnosis ◽  
Optical Coherence Tomography Angiography ◽  
Choroidal Melanoma ◽  
Fundus Photography ◽  
Imaging Features ◽  
Optical Coherence ◽  
Vascular Networks ◽  
Choroidal Nevus ◽  
Choroidal Nevi

Purpose: To describe the imaging features of choroidal nevus and melanoma using optical coherence tomography angiography, and evaluate the ability of this technique to establish the differential diagnosis based on the display of the tumor’s intrinsic vasculature. Methods: Comparative analysis of optical coherence tomography angiography findings in consecutive patients diagnosed with choroidal nevus or choroidal melanoma following a complete ophthalmic evaluation, including best-corrected visual acuity and several imaging studies: color fundus photography, B-scan ultrasound, spectral-domain optical coherence tomography, and optical coherence tomography angiography. Optical coherence tomography angiography was used to investigate qualitative differences in the tumor vasculature. Results: Thirty-six eyes (18 cases of choroidal nevus and 18 cases of choroidal melanoma) from 36 consecutive patients were included in the study. Only cases located posterior to equator were included to enable performance of all tests. On optical coherence tomography angiography, choroidal nevus showed well-delimited margins (78%), hyperreflective choroid capillary vasculature (83%), fewer avascular areas (17%), and neovascular membrane in one case (6%). Choroidal melanoma showed imprecise margins (72%), hyporeflective choroidal capillary vasculature (72%), multiple avascular areas (78%), and choroidal vascular changes (e.g. thick vascular networks or vascular loops; 45%). Conclusion: Optical coherence tomography angiography can provide useful information for assessing and differentiating between choroidal nevi and small melanomas. Significant differences between these conditions were found for the pattern of reflectivity, and presence/absence of avascular zones and vascular anomalies, which could be helpful for supporting the diagnosis.

scholarly journals Application of Multimodal and Molecular Imaging Techniques in the Detection of Choroidal Melanomas

2021 ◽  
Vol 10 ◽  
Author(s):  
Xuying Li ◽  
Lixiang Wang ◽  
Li Zhang ◽  
Fei Tang ◽  
Xin Wei
Keyword(s):  
Molecular Imaging ◽  
Benign Tumor ◽  
Malignant Tumors ◽  
Imaging Techniques ◽  
Choroidal Melanoma ◽  
Common Benign Tumor ◽  
Choroidal Melanomas ◽  
Choroidal Nevus ◽  
Choroidal Nevi

Choroidal melanomas are the most common ocular malignant tumors worldwide. The onset of such tumors is insidious, such that affected patients often have no pain or obvious discomfort during early stages. Notably, enucleation is required for patients with a severe choroidal melanoma, which can seriously impact their quality of life. Moreover, choroidal melanomas metastasize early, often to the liver; this eventually causes affected patients to die of liver failure. Therefore, early diagnosis of choroidal melanomas is extremely important. Unfortunately, an early choroidal melanoma is easily confused with a choroidal nevus, which is the most common benign tumor of the eye and does not often require surgical treatment. This review discusses recent advances in the use of multimodal and molecular imaging to identify choroidal melanomas and choroidal nevi, detect early metastasis, and diagnose patients with choroidal melanomas.

Hair cell changes after cationic stimulation of corti's organ

1989 ◽  
Vol 47 ◽  
pp. 798-799
Author(s):  
Cesar D. Fermin ◽  
Hans-Peter Zenner
Keyword(s):  
Organ Of Corti ◽  
Cross Sectional ◽  
Surface Areas ◽  
High K ◽  
Anatomical Arrangement ◽  
Cell Cytosol ◽  
High Concentrations ◽  
K Concentration ◽  
Cell Changes

Contraction of outer and inner hair cells (OHC&IHC) in the Organ of Corti (OC) of the inner ear is necessary for sound transduction. Getting at HC in vivo preparations is difficult. Thus, isolated HCs have been used to study OHC properties. Even though viability has been shown in isolated (iOHC) preparations by good responses to current and cationic stimulation, the contribution of adjoining cells can not be explained with iOHC preparations. This study was undertaken to examine changes in the OHC after expossure of the OHC to high concentrations of potassium (K) and sodium (Na), by carefully immersing the OC in either artifical endolymph or perilymph. After K and Na exposure, OCs were fixed with 3% glutaraldehyde, post-fixed in osmium, separated into base, middle and apex and embedded in Araldite™. One μm thick sections were prepared for analysis with the light and E.M. Cross sectional areas were measured with Bioquant™ software.Potassium and sodium both cause isolated guinea pig OHC to contract. In vivo high K concentration may cause uncontrolled and sustained contractions that could contribute to Meniere's disease. The behavior of OHC in the vivo setting might be very different from that of iOHC. We show here changes of the cell cytosol and cisterns caused by K and Na to OHC in situs. The table below shows results from cross sectional area measurements of OHC from OC that were exposed to either K or Na. As one would expect, from the anatomical arrangement of the OC, OHC#l that are supported by rigid tissue would probably be displaced (move) less than those OHC located away from the pillar. Surprisingly, cells in the middle turn of the cochlea changed their surface areas more than those at either end of the cochlea. Moreover, changes in surface area do not seem to differ between K and Na treated OCs.

scholarly journals Occupational Exposure to Carbon Nanotubes and Carbon Nanofibres: More Than a Cobweb

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 745
Author(s):  
Enrico Bergamaschi ◽  
Giacomo Garzaro ◽  
Georgia Wilson Jones ◽  
Martina Buglisi ◽  
Michele Caniglia ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Animal Studies ◽  
Chemical Properties ◽  
Biological Behavior ◽  
Cross Sectional ◽  
Carbon Nanofibres ◽  
Material Entity ◽  
Cross Sectional Design

Carbon nanotubes (CNTs) and carbon nanofibers (CNFs) are erroneously considered as singular material entities. Instead, they should be regarded as a heterogeneous class of materials bearing different properties eliciting peculiar biological outcomes both in vitro and in vivo. Given the pace at which the industrial production of CNTs/CNFs is increasing, it is becoming of utmost importance to acquire comprehensive knowledge regarding their biological activity and their hazardous effects in humans. Animal studies carried out by inhalation showed that some CNTs/CNFs species can cause deleterious effects such as inflammation and lung tissue remodeling. Their physico-chemical properties, biological behavior and biopersistence make them similar to asbestos fibers. Human studies suggest some mild effects in workers handling CNT/CNF. However, owing to their cross-sectional design, researchers have been as yet unable to firmly demonstrate a causal relationship between such an exposure and the observed effects. Estimation of acceptable exposure levels should warrant a proper risk management. The aim of this review is to challenge the conception of CNTs/CNFs as a single, unified material entity and prompt the establishment of standardized hazard and exposure assessment methodologies able to properly feeding risk assessment and management frameworks.

scholarly journals Simulating a Ground Truth for Transit Time Analysis of Indicator Dilution Curves

2020 ◽  
Vol 6 (3) ◽  
pp. 268-271
Author(s):  
Michael Reiß ◽  
Ady Naber ◽  
Werner Nahm
Keyword(s):  
Transit Time ◽  
Sampling Rate ◽  
Ground Truth ◽  
Indicator Dilution ◽  
Cross Sectional ◽  
In Vivo Measurements ◽  
Multiple Indicator Dilution ◽  
Transit Times ◽  
Dilution Curves

AbstractTransit times of a bolus through an organ can provide valuable information for researchers, technicians and clinicians. Therefore, an indicator is injected and the temporal propagation is monitored at two distinct locations. The transit time extracted from two indicator dilution curves can be used to calculate for example blood flow and thus provide the surgeon with important diagnostic information. However, the performance of methods to determine the transit time Δt cannot be assessed quantitatively due to the lack of a sufficient and trustworthy ground truth derived from in vivo measurements. Therefore, we propose a method to obtain an in silico generated dataset of differently subsampled indicator dilution curves with a ground truth of the transit time. This method allows variations on shape, sampling rate and noise while being accurate and easily configurable. COMSOL Multiphysics is used to simulate a laminar flow through a pipe containing blood analogue. The indicator is modelled as a rectangular function of concentration in a segment of the pipe. Afterwards, a flow is applied and the rectangular function will be diluted. Shape varying dilution curves are obtained by discrete-time measurement of the average dye concentration over different cross-sectional areas of the pipe. One dataset is obtained by duplicating one curve followed by subsampling, delaying and applying noise. Multiple indicator dilution curves were simulated, which are qualitatively matching in vivo measurements. The curves temporal resolution, delay and noise level can be chosen according to the requirements of the field of research. Various datasets, each containing two corresponding dilution curves with an existing ground truth transit time, are now available. With additional knowledge or assumptions regarding the detection-specific transfer function, realistic signal characteristics can be simulated. The accuracy of methods for the assessment of Δt can now be quantitatively compared and their sensitivity to noise evaluated.

Revisiting the Factors Influencing Teaching Choice Framework: Exploring What Fits with Virtual Teaching

2021 ◽  
pp. 097215092110153
Author(s):  
Sudhir Rana ◽  
Amit Kumar Singh ◽  
Shubham Singhania ◽  
Shubhangi Verma ◽  
Moon Moon Haque
Keyword(s):  
Higher Education ◽  
Technological Development ◽  
Learning Experience ◽  
New Technology ◽  
Business Management ◽  
Teaching Efficacy ◽  
Influential Factors ◽  
Cross Sectional ◽  
Factors Influencing ◽  
Virtual Teaching

The present study revisits the Factors Influencing Teaching Choice (FIT-Choice) framework and explores what motivates business management academicians in teaching virtually. The revisit is based on a quantitative cross-sectional research design using 256 responses collected from in-service business management academicians teaching post-graduate business courses in India, through a structured questionnaire. The exercise of revisiting the FIT-Choice framework in the context of virtual teaching in business management courses led us to find four new variables, that is, task demand and expert career, teaching efficacy, knowledge assimilation and institutional utility value, as well as suggest revising teaching and learning experience, task returns and values. The results reveal that some additional factors motivating business academicians are teaching efficacy, content expertise, learning of new technology, futuristic growth and opportunities, alternative career opportunities and personal branding. The study provides suggestions to the apex bodies, regulators of higher education and institutions to take a call on motivational and influential factors while drafting the job requirements in business schools. Finally, the study emphasizes the importance of infrastructural and technological development required to be achieved by higher education institutions.

scholarly journals Rectus Femoris Mimicking Ultrasound Phantom for Muscle Mass Assessment: Design, Research, and Training Application

2021 ◽  
Vol 10 (12) ◽  
pp. 2721
Author(s):  
Nobuto Nakanishi ◽  
Shigeaki Inoue ◽  
Rie Tsutsumi ◽  
Yusuke Akimoto ◽  
Yuko Ono ◽  
...  
Keyword(s):  
Measurement Accuracy ◽  
Rectus Femoris ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Phantom Model ◽  
Ultrasound Measurements ◽  
Ultrasound Phantom

Ultrasound has become widely used as a means to measure the rectus femoris muscle in the acute and chronic phases of critical illness. Despite its noninvasiveness and accessibility, its accuracy highly depends on the skills of the technician. However, few ultrasound phantoms for the confirmation of its accuracy or to improve technical skills exist. In this study, the authors created a novel phantom model and used it for investigating the accuracy of measurements and for training. Study 1 investigated how various conditions affect ultrasound measurements such as thickness, cross-sectional area, and echogenicity. Study 2 investigated if the phantom can be used for the training of various health care providers in vitro and in vivo. Study 1 showed that thickness, cross-sectional area, and echogenicity were affected by probe compression strength, probe angle, phantom compression, and varying equipment. Study 2 in vitro showed that using the phantom for training improved the accuracy of the measurements taken within the phantom, and Study 2 in vivo showed the phantom training had a short-term effect on improving the measurement accuracy in a human volunteer. The new ultrasound phantom model revealed that various conditions affected ultrasound measurements, and phantom training improved the measurement accuracy.

scholarly journals Relationship between NAFLD and Periodontal Disease from the View of Clinical and Basic Research, and Immunological Response

2021 ◽  
Vol 22 (7) ◽  
pp. 3728
Author(s):  
Masahiro Hatasa ◽  
Sumiko Yoshida ◽  
Hirokazu Takahashi ◽  
Kenichi Tanaka ◽  
Yoshihito Kubotsu ◽  
...  
Keyword(s):  
Risk Factor ◽  
Periodontal Disease ◽  
Alveolar Bone ◽  
Basic Research ◽  
Epidemiological Studies ◽  
Cross Sectional ◽  
Periodontopathic Bacteria ◽  
In Vivo Animal Model ◽  
The Relationship

Periodontal disease is an inflammatory disease caused by pathogenic oral microorganisms that leads to the destruction of alveolar bone and connective tissues around the teeth. Although many studies have shown that periodontal disease is a risk factor for systemic diseases, such as type 2 diabetes and cardiovascular diseases, the relationship between nonalcoholic fatty liver disease (NAFLD) and periodontal disease has not yet been clarified. Thus, the purpose of this review was to reveal the relationship between NAFLD and periodontal disease based on epidemiological studies, basic research, and immunology. Many cross-sectional and prospective epidemiological studies have indicated that periodontal disease is a risk factor for NAFLD. An in vivo animal model revealed that infection with periodontopathic bacteria accelerates the progression of NAFLD accompanied by enhanced steatosis. Moreover, the detection of periodontopathic bacteria in the liver may demonstrate that the bacteria have a direct impact on NAFLD. Furthermore, Porphyromonas gingivalis lipopolysaccharide induces inflammation and accumulation of intracellular lipids in hepatocytes. Th17 may be a key molecule for explaining the relationship between periodontal disease and NAFLD. In this review, we attempted to establish that oral health is essential for systemic health, especially in patients with NAFLD.

scholarly journals Patterning Vascular Networks In Vivo for Tissue Engineering Applications

2015 ◽  
Vol 21 (5) ◽  
pp. 509-517 ◽  
Author(s):  
Ritika R. Chaturvedi ◽  
Kelly R. Stevens ◽  
Ricardo D. Solorzano ◽  
Robert E. Schwartz ◽  
Jeroen Eyckmans ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Vascular Networks ◽  
Engineering Applications
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