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Moghaddam AS, Reissig LF, Geyer SH, Weninger WJ. Arterio-venous Anastomoses of the Sucquet-Hoyer Type: Complexity and Distribution in the Human Dermis. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2024; 30:334-341. [PMID: 38442214 DOI: 10.1093/mam/ozae012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 12/19/2023] [Accepted: 02/12/2024] [Indexed: 03/07/2024]
Abstract
Our study aims at providing detailed information on numbers, form, and spatial distribution of arterio-venous anastomoses of the Sucquet-Hoyer type in the dermis of the nail bed, nail fold corner, thumb pad, arm, nose, glabella, lip, and ear. It further aims at providing a system, which relies on objective morphologic criteria for classifying Sucquet-Hoyer canals (SHCs). Using high-resolution episcopic microscopy (HREM), digital volume data of eight samples of each skin region were produced. Virtual three-dimensional (3D) models of the dermally located SHCs were created, and their 3D tortuosity (τ) values were determined. Dermal SHCs were identified in all 24 finger samples and in 1 lip sample. Beneath a field of 2 × 2 mm2, an average of four were located in the nail bed, three in the dermis of the thumb pad, and one in the dermis of the nail fold corner. Only a single dermal SHC was found in one lip sample. No SHCs were observed in the dermis of the other samples. The τ values of the SHCs ranged from 1.11 to 10. Building on these values, a classification system was designed, which distinguishes four SHC classes. The dermal distribution of the SHCs of different classes was similar in all specimens.
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Affiliation(s)
- Atieh S Moghaddam
- Division of Anatomy, MIC, Center for Anatomy and Cell Biology, Medical University of Vienna, Währinger Strasse 13, 1090 Vienna, Austria
| | - Lukas F Reissig
- Division of Anatomy, MIC, Center for Anatomy and Cell Biology, Medical University of Vienna, Währinger Strasse 13, 1090 Vienna, Austria
| | - Stefan H Geyer
- Division of Anatomy, MIC, Center for Anatomy and Cell Biology, Medical University of Vienna, Währinger Strasse 13, 1090 Vienna, Austria
| | - Wolfgang J Weninger
- Division of Anatomy, MIC, Center for Anatomy and Cell Biology, Medical University of Vienna, Währinger Strasse 13, 1090 Vienna, Austria
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Bajwa MS, Bashir MM, Bajwa MH, Iqbal Z, Salahuddin MA, Hussain A, Shahzad F. How long to wait after local infiltration anaesthesia: systematic review. BJS Open 2023; 7:zrad089. [PMID: 37768699 PMCID: PMC10538258 DOI: 10.1093/bjsopen/zrad089] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 07/27/2023] [Indexed: 09/29/2023] Open
Abstract
BACKGROUND Conflicting evidence exists regarding the optimal waiting time for stable analgesic and vasoconstrictive effects after local infiltration of lidocaine with epinephrine. An objective review is needed to dispel surgical dogma. METHODS This systematic review (PROSPERO ID: CRD42022362414) included RCTs and prospective cohort studies. Primary outcomes were (1) onset of analgesia and (2) onset of stable hypoperfusion, assessed directly, or measured indirectly using perfusion imaging. Other data extracted include waiting strategies, means of outcome assessment, anaesthetic concentrations, volume/endpoint of infiltration, and injection sites. Methodological quality was evaluated using the Cochrane risk-of-bias tool for randomized trials. Articles describing waiting strategies were critically appraised by the Joanna Briggs Institute tools. RESULTS Twenty-four articles were analysed, comprising 1013 participants. Ten investigated analgesia onset. Their pooled mean was 2.1 min (range 0.4-9.0 min). This varied with anatomic site and targeted nerve diameter. Fourteen articles investigated onset of stable hypoperfusion. Four observed bleeding intraoperatively, finding the minimum time to hypoperfusion at 7.0 min in the eyelid skin and 25.0 min in the upper limb. The ten remaining studies used perfusion imaging, reporting a wide range of results (0.0-30.0 min) due to differences in anatomic sites and depth, resolution and artefacts. Studies using near-infrared reflectance spectroscopy and hyperspectral imaging correlated with clinical observations. Thirteen articles discussed waiting strategies, seven relating to large-volume tumescent local infiltration anaesthesia. Different waiting strategies exist for emergency, arthroscopic and cosmetic surgeries, according to the degree of hypoperfusion required. In tumescent liposuction, waiting 10.0-60.0 min is the norm. CONCLUSION Current literature suggests that around 2 min are required for most patients to achieve complete analgesia in all sites and with all anaesthesia concentrations. Waiting around 7 min in eyelids and at least 25 min in other regions results in optimal hypoperfusion. The strategies discussed inform decisions of when and how long to wait.
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Affiliation(s)
- Mohammad Suleman Bajwa
- Department of Plastic & Reconstructive Surgery/Mayo Burn Centre, Mayo Hospital, King Edward Medical University, Lahore, Pakistan
- Department of Surgery, Montefiore Medical Center, New York, USA
| | - Muhammad Mustehsan Bashir
- Department of Plastic & Reconstructive Surgery/Mayo Burn Centre, Mayo Hospital, King Edward Medical University, Lahore, Pakistan
| | | | - Zafar Iqbal
- Department of Plastic & Reconstructive Surgery/Mayo Burn Centre, Mayo Hospital, King Edward Medical University, Lahore, Pakistan
| | - Muhammad Aizaz Salahuddin
- Department of Plastic & Reconstructive Surgery/Mayo Burn Centre, Mayo Hospital, King Edward Medical University, Lahore, Pakistan
| | - Ahmad Hussain
- Department of Plastic & Reconstructive Surgery/Mayo Burn Centre, Mayo Hospital, King Edward Medical University, Lahore, Pakistan
| | - Farooq Shahzad
- Plastic & Reconstructive Surgery Service, Memorial Sloan-Kettering Cancer Center, New York, New York, USA
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Kim D, Ahn J, Park E, Kim JY, Kim C. In vivo quantitative photoacoustic monitoring of corticosteroid-induced vasoconstriction. JOURNAL OF BIOMEDICAL OPTICS 2023; 28:082805. [PMID: 36844430 PMCID: PMC9951467 DOI: 10.1117/1.jbo.28.8.082805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Accepted: 02/02/2023] [Indexed: 06/18/2023]
Abstract
SIGNIFICANCE Corticosteroids-commonly prescribed medications for skin diseases-inhibit the secretion of vasodilators, such as prostaglandin, thereby exerting anti-inflammatory action by constricting capillaries in the dermis. The effectiveness of corticosteroids is determined by the degree of vasoconstriction followed by skin whitening, namely, the blanching effect. However, the current method of observing the blanching effect indirectly evaluates the effects of corticosteroids. AIM In this study, we employed optical-resolution photoacoustic (PA) microscopy (OR-PAM) to directly visualize the blood vessels and quantitatively evaluate vasoconstriction. APPROACH Using OR-PAM, the vascular density in mice skin was monitored for 60 min after performing each experimental procedure for four groups, and the vasoconstriction was quantified. Volumetric PA data were segmented into the papillary dermis, reticular dermis, and hypodermis based on the vascular characteristics obtained through OR-PAM. The vasoconstrictive effect of each skin layer was quantified according to the dermatological treatment method. RESULTS In the case of corticosteroid topical application, vasoconstriction was observed in the papillary ( 56.4 ± 10.9 % ) and reticular ( 45.1 ± 4.71 % ) dermis. For corticosteroid subcutaneous injection, constriction was observed solely in the reticular ( 49.5 ± 9.35 % ) dermis. In contrast, no vasoconstrictions were observed with nonsteroidal topical application. CONCLUSIONS Our results indicate that OR-PAM can quantitatively monitor the vasoconstriction induced by corticosteroids, thereby validating OR-PAMs potential as a practical evaluation tool for predicting the effectiveness of corticosteroids in dermatology.
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Affiliation(s)
- Donggyu Kim
- Pohang University of Science and Technology, Departments of Electrical Engineering, Convergence IT Engineering, Mechanical Engineering, Medical Science and Engineering, and Medical Device Innovation Center Group, Pohang, Republic of Korea
| | - Joongho Ahn
- Pohang University of Science and Technology, Departments of Electrical Engineering, Convergence IT Engineering, Mechanical Engineering, Medical Science and Engineering, and Medical Device Innovation Center Group, Pohang, Republic of Korea
| | - Eunwoo Park
- Pohang University of Science and Technology, Departments of Electrical Engineering, Convergence IT Engineering, Mechanical Engineering, Medical Science and Engineering, and Medical Device Innovation Center Group, Pohang, Republic of Korea
| | - Jin Young Kim
- Pohang University of Science and Technology, Departments of Electrical Engineering, Convergence IT Engineering, Mechanical Engineering, Medical Science and Engineering, and Medical Device Innovation Center Group, Pohang, Republic of Korea
| | - Chulhong Kim
- Pohang University of Science and Technology, Departments of Electrical Engineering, Convergence IT Engineering, Mechanical Engineering, Medical Science and Engineering, and Medical Device Innovation Center Group, Pohang, Republic of Korea
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Guillot AJ, Martínez-Navarrete M, Zinchuk-Mironova V, Melero A. Microneedle-assisted transdermal delivery of nanoparticles: Recent insights and prospects. WILEY INTERDISCIPLINARY REVIEWS. NANOMEDICINE AND NANOBIOTECHNOLOGY 2023:e1884. [PMID: 37041036 DOI: 10.1002/wnan.1884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 02/01/2023] [Accepted: 02/13/2023] [Indexed: 04/13/2023]
Abstract
Transdermal delivery of drugs offers an interesting alternative for the administration of molecules that present certain troubles when delivered by the oral route. It can produce systemic effects or perform a local action when the formulation exerts an optimal controlled drug release or a targeted delivery to the specific cell type or site. It also avoids several inconveniences of the oral administration such as the hepatic first pass effect, gastric pH-induced hydrolysis, drug malabsorption because of certain diseases or surgeries, and unpleasant organoleptic properties. Nanomedicine and microneedle array patches (MAPs) are two of the trendiest delivery systems applied to transdermal research nowadays. However, the skin is a protective barrier and nanoparticles (NPs) cannot pass through the intact stratum corneum. The association of NPs and MAPs (NPs@MAPs) work synergistically, since MAPs assist NPs to bypass the outer skin layers, and NPs contribute to the system providing controlled drug release and targeted delivery. Vaccination and tailored therapies have been proposed as fields where both NPs and MAPs have great potential due to inherent characteristics. MAPs conception and easy use could allow self-administration and therefore facilitate mass vaccination campaigns in undeveloped areas with weak healthcare services. Additionally, nanomedicine is being explored as a platform to personalize therapies in such an important field as oncology. In this work we show recent insights that prove the benefits of NPs@MAPs association and analyze the prospects and the discrete interest of the industry in NPs@MAPs, evaluating different limiting steps that restricts NPs@MAPs translation to the clinical practice. This article is categorized under: Nanotechnology Approaches to Biology > NA Therapeutic Approaches and Drug Discovery > NA.
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Affiliation(s)
- Antonio José Guillot
- Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, University of Valencia, Av. Vicent Andrés Estelles s/n, 46100, Burjassot, Spain
| | - Miquel Martínez-Navarrete
- Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, University of Valencia, Av. Vicent Andrés Estelles s/n, 46100, Burjassot, Spain
| | - Valeria Zinchuk-Mironova
- Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, University of Valencia, Av. Vicent Andrés Estelles s/n, 46100, Burjassot, Spain
| | - Ana Melero
- Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, University of Valencia, Av. Vicent Andrés Estelles s/n, 46100, Burjassot, Spain
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5
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Holroyd NA, Walsh C, Gourmet L, Walker-Samuel S. Quantitative Image Processing for Three-Dimensional Episcopic Images of Biological Structures: Current State and Future Directions. Biomedicines 2023; 11:909. [PMID: 36979887 PMCID: PMC10045950 DOI: 10.3390/biomedicines11030909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 03/03/2023] [Accepted: 03/10/2023] [Indexed: 03/17/2023] Open
Abstract
Episcopic imaging using techniques such as High Resolution Episcopic Microscopy (HREM) and its variants, allows biological samples to be visualized in three dimensions over a large field of view. Quantitative analysis of episcopic image data is undertaken using a range of methods. In this systematic review, we look at trends in quantitative analysis of episcopic images and discuss avenues for further research. Papers published between 2011 and 2022 were analyzed for details about quantitative analysis approaches, methods of image annotation and choice of image processing software. It is shown that quantitative processing is becoming more common in episcopic microscopy and that manual annotation is the predominant method of image analysis. Our meta-analysis highlights where tools and methods require further development in this field, and we discuss what this means for the future of quantitative episcopic imaging, as well as how annotation and quantification may be automated and standardized across the field.
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Affiliation(s)
| | - Claire Walsh
- Centre for Computational Medicine, University College London, London WC1E 6DD, UK
- Department of Mechanical Engineering, University College London, London WC1E 7JE, UK
| | - Lucie Gourmet
- Centre for Computational Medicine, University College London, London WC1E 6DD, UK
| | - Simon Walker-Samuel
- Centre for Computational Medicine, University College London, London WC1E 6DD, UK
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Guillot AJ, Martínez-Navarrete M, Garrigues TM, Melero A. Skin drug delivery using lipid vesicles: A starting guideline for their development. J Control Release 2023; 355:624-654. [PMID: 36775245 DOI: 10.1016/j.jconrel.2023.02.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 02/02/2023] [Accepted: 02/02/2023] [Indexed: 02/14/2023]
Abstract
Lipid vesicles can provide a cost-effective enhancement of skin drug absorption when vesicle production process is optimised. It is an important challenge to design the ideal vesicle, since their properties and features are related, as changes in one affect the others. Here, we review the main components, preparation and characterization methods commonly used, and the key properties that lead to highly efficient vesicles for transdermal drug delivery purposes. We stand by size, deformability degree and drug loading, as the most important vesicle features that determine the further transdermal drug absorption. The interest in this technology is increasing, as demonstrated by the exponential growth of publications on the topic. Although long-term preservation and scalability issues have limited the commercialization of lipid vesicle products, freeze-drying and modern escalation methods overcome these difficulties, thus predicting a higher use of these technologies in the market and clinical practice.
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Affiliation(s)
- Antonio José Guillot
- Department of Pharmacy and Pharmaceutical Technology and Parasitology, University of Valencia, Avda. Vicente A. Estelles SN, Burjassot (Valencia), Spain
| | - Miquel Martínez-Navarrete
- Department of Pharmacy and Pharmaceutical Technology and Parasitology, University of Valencia, Avda. Vicente A. Estelles SN, Burjassot (Valencia), Spain
| | - Teresa M Garrigues
- Department of Pharmacy and Pharmaceutical Technology and Parasitology, University of Valencia, Avda. Vicente A. Estelles SN, Burjassot (Valencia), Spain
| | - Ana Melero
- Department of Pharmacy and Pharmaceutical Technology and Parasitology, University of Valencia, Avda. Vicente A. Estelles SN, Burjassot (Valencia), Spain.
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7
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Calcutt JJ, Roberts MS, Anissimov YG. Predicting Viable Skin Concentration: Modelling the Subpapillary Plexus. Pharm Res 2022; 39:783-793. [PMID: 35266087 PMCID: PMC9090854 DOI: 10.1007/s11095-022-03215-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 02/22/2022] [Indexed: 12/14/2022]
Abstract
The skin concentration of a substance after a topical application or exposure determines both local treatment outcomes and the dermal toxicity assessment of various products. However, quantifying the time course of those concentrations at skin effect sites, such as the viable epidermal, superficial dermis and appendages in humans is especially problematic in vivo, making physiologically based mathematical modelling an essential tool to meet this need. This work further develops our published physiologically based pharmacokinetic and COMSOL based dermal transport modelling by considering the impact of the superficial subpapillary dermal plexus, which we represent as two well stirred compartments. The work also studied the impact on dermal concentrations of subpapillary plexus size, depth, blood velocity and density of subpapillary plexus vessels. Sensitivity analyses are used to define the most important transport determinants of skin concentrations after topical application of a substance, with previously published results used to validate the resulting analyses. This resulting model describes the available experimental data better than previous models, especially at deeper dermal depths.
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Affiliation(s)
- Joshua J Calcutt
- School of Environment and Science, Griffith University, Gold Coast, Queensland, 4222, Australia
| | - Michael S Roberts
- University of South Australia, Clinical Health Sciences and Basil Hetzel Institute for Translational Health Research, Adelaide, 5011, Australia
- Diamantina Institute, University of Queensland, Brisbane, 4072, Australia
| | - Yuri G Anissimov
- School of Environment and Science, Griffith University, Gold Coast, Queensland, 4222, Australia.
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8
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Artefacts in Volume Data Generated with High Resolution Episcopic Microscopy (HREM). Biomedicines 2021; 9:biomedicines9111711. [PMID: 34829939 PMCID: PMC8615656 DOI: 10.3390/biomedicines9111711] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/11/2021] [Accepted: 11/16/2021] [Indexed: 11/23/2022] Open
Abstract
High resolution episcopic microscopy (HREM) produces digital volume data by physically sectioning histologically processed specimens, while capturing images of the subsequently exposed block faces. Our study aims to systematically define the spectrum of typical artefacts inherent to HREM data and to research their effect on the interpretation of the phenotype of wildtype and mutant mouse embryos. A total of 607 (198 wildtypes, 409 mutants) HREM data sets of mouse embryos harvested at embryonic day (E) 14.5 were systematically and comprehensively examined. The specimens had been processed according to essentially identical protocols. Each data set comprised 2000 to 4000 single digital images. Voxel dimensions were 3 × 3 × 3 µm3. Using 3D volume models and virtual resections, we identified a number of characteristic artefacts and grouped them according to their most likely causality. Furthermore, we highlight those that affect the interpretation of embryo data and provide examples for artefacts mimicking tissue defects and structural pathologies. Our results aid in optimizing specimen preparation and data generation, are vital for the correct interpretation of HREM data and allow distinguishing tissue defects and pathologies from harmless artificial alterations. In particular, they enable correct diagnosis of pathologies in mouse embryos serving as models for deciphering the mechanisms of developmental disorders.
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Wendling O, Hentsch D, Jacobs H, Lemercier N, Taubert S, Pertuy F, Vonesch JL, Sorg T, Di Michele M, Le Cam L, Rosahl T, Carballo-Jane E, Liu M, Mu J, Mark M, Herault Y. High Resolution Episcopic Microscopy for Qualitative and Quantitative Data in Phenotyping Altered Embryos and Adult Mice Using the New "Histo3D" System. Biomedicines 2021; 9:767. [PMID: 34356832 PMCID: PMC8301480 DOI: 10.3390/biomedicines9070767] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/21/2021] [Accepted: 06/23/2021] [Indexed: 12/27/2022] Open
Abstract
3D imaging in animal models, during development or in adults, facilitates the identification of structural morphological changes that cannot be achieved with traditional 2D histological staining. Through the reconstruction of whole embryos or a region-of-interest, specific changes are better delimited and can be easily quantified. We focused here on high-resolution episcopic microscopy (HREM), and its potential for visualizing and quantifying the organ systems of normal and genetically altered embryos and adult organisms. Although the technique is based on episcopic images, these are of high resolution and are close to histological quality. The images reflect the tissue structure and densities revealed by histology, albeit in a grayscale color map. HREM technology permits researchers to take advantage of serial 2D aligned stacks of images to perform 3D reconstructions. Three-dimensional visualization allows for an appreciation of topology and morphology that is difficult to achieve with classical histological studies. The nature of the data lends itself to novel forms of computational analysis that permit the accurate quantitation and comparison of individual embryos in a manner that is impossible with histology. Here, we have developed a new HREM prototype consisting of the assembly of a Leica Biosystems Nanocut rotary microtome with optics and a camera. We describe some examples of applications in the prenatal and adult lifestage of the mouse to show the added value of HREM for phenotyping experimental cohorts to compare and quantify structure volumes. At prenatal stages, segmentations and 3D reconstructions allowed the quantification of neural tissue and ventricular system volumes of normal brains at E14.5 and E16.5 stages. 3D representations of normal cranial and peripheric nerves at E15.5 and of the normal urogenital system from stages E11.5 to E14.5 were also performed. We also present a methodology to quantify the volume of the atherosclerotic plaques of ApoEtm1Unc/tm1Unc mutant mice and illustrate a 3D reconstruction of knee ligaments in adult mice.
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Affiliation(s)
- Olivia Wendling
- CNRS, INSERM, CELPHEDIA, PHENOMIN-Institut Clinique de la Souris (ICS), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (O.W.); (H.J.); (F.P.); (T.S.); (M.M.)
- CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (D.H.); (S.T.); (J.-L.V.)
| | - Didier Hentsch
- CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (D.H.); (S.T.); (J.-L.V.)
| | - Hugues Jacobs
- CNRS, INSERM, CELPHEDIA, PHENOMIN-Institut Clinique de la Souris (ICS), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (O.W.); (H.J.); (F.P.); (T.S.); (M.M.)
| | | | - Serge Taubert
- CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (D.H.); (S.T.); (J.-L.V.)
| | - Fabien Pertuy
- CNRS, INSERM, CELPHEDIA, PHENOMIN-Institut Clinique de la Souris (ICS), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (O.W.); (H.J.); (F.P.); (T.S.); (M.M.)
| | - Jean-Luc Vonesch
- CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (D.H.); (S.T.); (J.-L.V.)
| | - Tania Sorg
- CNRS, INSERM, CELPHEDIA, PHENOMIN-Institut Clinique de la Souris (ICS), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (O.W.); (H.J.); (F.P.); (T.S.); (M.M.)
| | - Michela Di Michele
- Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM U1194, Université Montpellier, 34298 Montpellier, France; (M.D.M.); (L.L.C.)
- Institut Régional du Cancer de Montpellier (ICM), Université Montpellier, 34298 Montpellier, France
| | - Laurent Le Cam
- Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM U1194, Université Montpellier, 34298 Montpellier, France; (M.D.M.); (L.L.C.)
- Institut Régional du Cancer de Montpellier (ICM), Université Montpellier, 34298 Montpellier, France
| | - Thomas Rosahl
- Merck & Co. Inc., Kenilworth, NJ 07033, USA; (T.R.); (E.C.-J.); (M.L.); (J.M.)
| | - Ester Carballo-Jane
- Merck & Co. Inc., Kenilworth, NJ 07033, USA; (T.R.); (E.C.-J.); (M.L.); (J.M.)
| | - Mindy Liu
- Merck & Co. Inc., Kenilworth, NJ 07033, USA; (T.R.); (E.C.-J.); (M.L.); (J.M.)
| | - James Mu
- Merck & Co. Inc., Kenilworth, NJ 07033, USA; (T.R.); (E.C.-J.); (M.L.); (J.M.)
| | - Manuel Mark
- CNRS, INSERM, CELPHEDIA, PHENOMIN-Institut Clinique de la Souris (ICS), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (O.W.); (H.J.); (F.P.); (T.S.); (M.M.)
- CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (D.H.); (S.T.); (J.-L.V.)
- Service de Biologie de la Reproduction, Hôpitaux Universitaires de Strasbourg (HUS), CEDEX, 67091 Strasbourg, France
| | - Yann Herault
- CNRS, INSERM, CELPHEDIA, PHENOMIN-Institut Clinique de la Souris (ICS), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (O.W.); (H.J.); (F.P.); (T.S.); (M.M.)
- CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, 1 Rue Laurent Fries, 67404 Illkirch Graffenstaden, France; (D.H.); (S.T.); (J.-L.V.)
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10
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Saknite I, Zhao Z, Patrinely JR, Byrne M, Jagasia M, Tkaczyk ER. Individual cell motion in healthy human skin microvasculature by reflectance confocal video microscopy. Microcirculation 2020; 27:e12621. [PMID: 32304109 PMCID: PMC7554192 DOI: 10.1111/micc.12621] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 03/06/2020] [Accepted: 04/11/2020] [Indexed: 12/14/2022]
Abstract
OBJECTIVE To describe upper dermal microvasculature of healthy human skin in terms of density and size of cutaneous blood vessels, leukocyte velocity, and leukocyte interactions with the endothelium. METHODS We used a reflectance confocal microscope, the VivaScope 1500, to acquire videos of individual cell motion. RESULTS We found no rolling leukocytes in the upper microvasculature of ten healthy subjects. We observed "paused" leukocytes, that is, leukocytes that temporarily stop, coinciding with the simultaneous stopping of the rest of the blood flow. We imaged more paused (median: 1.0 per subject) and adherent (1.5) leukocytes in the forearm than in the chest (median 0 paused and 0 adherent per subject) per 5 minutes of videos per body site. Leukocytes were paused for a median of 7 seconds in the forearm and 3 seconds in the chest, and we found no correlation between this parameter and the blood vessel or leukocyte size. We visualized blood flow change direction. Flowing leukocyte velocities followed a lognormal distribution and were on average higher in the chest (117 µm/s) than in the forearm (66 µm/s). CONCLUSION The proposed method and reported values in healthy skin provide new insights into intact human skin microcirculation.
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Affiliation(s)
- Inga Saknite
- Vanderbilt Dermatology Translational Research Clinic,
Department of Dermatology, Vanderbilt University Medical Center, Nashville, TN,
USA
| | - Zijun Zhao
- Vanderbilt Dermatology Translational Research Clinic,
Department of Dermatology, Vanderbilt University Medical Center, Nashville, TN,
USA
- Dermatology Service and Research Service, Tennessee Valley
Healthcare System, Department of Veterans Affairs, Nashville, TN, USA
- Vanderbilt University School of Medicine, Nashville, TN,
USA
| | - J. Randall Patrinely
- Vanderbilt Dermatology Translational Research Clinic,
Department of Dermatology, Vanderbilt University Medical Center, Nashville, TN,
USA
- Dermatology Service and Research Service, Tennessee Valley
Healthcare System, Department of Veterans Affairs, Nashville, TN, USA
- Vanderbilt University School of Medicine, Nashville, TN,
USA
| | - Michael Byrne
- Division of Hematology/Oncology, Department of Medicine,
Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt-Ingram Cancer Center, Nashville, TN, USA
| | - Madan Jagasia
- Division of Hematology/Oncology, Department of Medicine,
Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt-Ingram Cancer Center, Nashville, TN, USA
| | - Eric R. Tkaczyk
- Vanderbilt Dermatology Translational Research Clinic,
Department of Dermatology, Vanderbilt University Medical Center, Nashville, TN,
USA
- Dermatology Service and Research Service, Tennessee Valley
Healthcare System, Department of Veterans Affairs, Nashville, TN, USA
- Vanderbilt-Ingram Cancer Center, Nashville, TN, USA
- Department of Biomedical Engineering, Vanderbilt
University, Nashville, TN, USA
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11
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Dabiri B, Kampusch S, Geyer SH, Le VH, Weninger WJ, Széles JC, Kaniusas E. High-Resolution Episcopic Imaging for Visualization of Dermal Arteries and Nerves of the Auricular Cymba Conchae in Humans. Front Neuroanat 2020; 14:22. [PMID: 32477074 PMCID: PMC7236887 DOI: 10.3389/fnana.2020.00022] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 03/27/2020] [Indexed: 12/16/2022] Open
Abstract
Therapeutic applications of auricular vagus nerve stimulation (VNS) have drawn recent attention. Since the targeted stimulation process and parameters depend on the electrode–tissue interaction, the lack of structural anatomical information on innervation and vascularization of the auricle restrain the current optimization of stimulation paradigms. For the first time, we employed high-resolution episcopic imaging (HREM) to generate histologic volume data from donated human cadaver ears. Optimal parameters for specimen preparation were evaluated. Anatomical 3D vascular and nerve structures were reconstructed in one sample of an auricular cymba conchae (CC). The feasibility of HREM to visualize anatomical structures was assessed in that diameters, occupied areas, volumes, and mutual distances between auricular arteries, nerves, and veins were registered. The selected region of CC (3 × 5.5 mm) showed in its cross-sections 21.7 ± 2.7 (mean ± standard deviation) arteries and 14.66 ± 2.74 nerve fibers. Identified nerve diameters were 33.66 ± 21.71 μm, and arteries had diameters in the range of 71.58 ± 80.70 μm. The respective occupied area showed a share of, on average, 2.71% and 0.3% for arteries and nerves, respectively, and similar volume occupancy for arteries and nerves. Inter-centroid minimum distance between arteries and nerves was 274 ± 222 μm. The density of vessels and nerves around a point within CC on a given grid was assessed, showing that 50% of all vessels and nerves were found in a radial distance of 1.6–1.8 mm from any of these points, which is strategically relevant when using stimulation needles in the auricle for excitation of nerves. HREM seems suitable for anatomical studies of the human ear. A 3D model of CC was established in the micrometer scale, which forms the basis for future optimization of the auricular VNS. Obviously, the presented single cadaver study needs to be validated by additional anatomical data on the innervation and vascularization of the auricle.
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Affiliation(s)
- Babak Dabiri
- Institute of Electrodynamics, Microwave and Circuit Engineering, Vienna University of Technology, Vienna, Austria
| | - Stefan Kampusch
- Institute of Electrodynamics, Microwave and Circuit Engineering, Vienna University of Technology, Vienna, Austria.,SzeleSTIM GmbH, Vienna, Austria
| | - Stefan H Geyer
- Division of Anatomy, MIC, Medical University of Vienna, Vienna, Austria
| | - Van Hoang Le
- Institute of Electrodynamics, Microwave and Circuit Engineering, Vienna University of Technology, Vienna, Austria
| | | | - Jozsef Constantin Széles
- Department for Vascular Surgery, University Clinic for Surgery, Medical University of Vienna, Vienna, Austria
| | - Eugenijus Kaniusas
- Institute of Electrodynamics, Microwave and Circuit Engineering, Vienna University of Technology, Vienna, Austria.,SzeleSTIM GmbH, Vienna, Austria
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12
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High-Resolution Episcopic Microscopy (HREM): Looking Back on 13 Years of Successful Generation of Digital Volume Data of Organic Material for 3D Visualisation and 3D Display. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9183826] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
High-resolution episcopic microscopy (HREM) is an imaging technique that permits the simple and rapid generation of three-dimensional (3D) digital volume data of histologically embedded and physically sectioned specimens. The data can be immediately used for high-detail 3D analysis of a broad variety of organic materials with all modern methods of 3D visualisation and display. Since its first description in 2006, HREM has been adopted as a method for exploring organic specimens in many fields of science, and it has recruited a slowly but steadily growing user community. This review aims to briefly introduce the basic principles of HREM data generation and to provide an overview of scientific publications that have been published in the last 13 years involving HREM imaging. The studies to which we refer describe technical details and specimen-specific protocols, and provide examples of the successful use of HREM in biological, biomedical and medical research. Finally, the limitations, potentials and anticipated further improvements are briefly outlined.
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13
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Liu M, Drexler W. Optical coherence tomography angiography and photoacoustic imaging in dermatology. Photochem Photobiol Sci 2019; 18:945-962. [PMID: 30735220 DOI: 10.1039/c8pp00471d] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Optical coherence tomography angiography (OCTA) is a relatively novel functional extension of the widely accepted ophthalmic imaging tool named optical coherence tomography (OCT). Since OCTA's debut in ophthalmology, researchers have also been trying to expand its translational application in dermatology. The ability of OCTA to resolve microvasculature has shown promising results in imaging skin diseases. Meanwhile, photoacoustic imaging (PAI), which uses laser pulse induced ultrasound waves as the signal, has been studied to differentiate human skin layers and to help in skin disease diagnosis. This perspective article gives a short review of OCTA and PAI in the field of photodermatology. After an introduction to the principles of OCTA and PAI, we describe the most updated results of skin disease imaging using these two optical imaging modalities. We also place emphasis on dual modality imaging combining OCTA and photoacoustic tomography (PAT) for dermatological applications. In the end, the challenges and prospects of these two imaging modalities in dermatology are discussed.
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Affiliation(s)
- Mengyang Liu
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, 1090 Vienna, Austria.
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14
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Visualising the Cardiovascular System of Embryos of Biomedical Model Organisms with High Resolution Episcopic Microscopy (HREM). J Cardiovasc Dev Dis 2018; 5:jcdd5040058. [PMID: 30558275 PMCID: PMC6306920 DOI: 10.3390/jcdd5040058] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 12/09/2018] [Accepted: 12/11/2018] [Indexed: 12/17/2022] Open
Abstract
The article will briefly introduce the high-resolution episcopic microscopy (HREM) technique and will focus on its potential for researching cardiovascular development and remodelling in embryos of biomedical model organisms. It will demonstrate the capacity of HREM for analysing the cardiovascular system of normally developed and genetically or experimentally malformed zebrafish, frog, chick and mouse embryos in the context of the whole specimen and will exemplarily show the possibilities HREM offers for comprehensive visualisation of the vasculature of adult human skin. Finally, it will provide examples of the successful application of HREM for identifying cardiovascular malformations in genetically altered mouse embryos produced in the deciphering the mechanisms of developmental disorders (DMDD) program.
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15
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Zhao Y, Applegate MB, Istfan R, Pande A, Roblyer D. Quantitative real-time pulse oximetry with ultrafast frequency-domain diffuse optics and deep neural network processing. BIOMEDICAL OPTICS EXPRESS 2018; 9:5997-6008. [PMID: 31065408 PMCID: PMC6491012 DOI: 10.1364/boe.9.005997] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 10/23/2018] [Accepted: 10/24/2018] [Indexed: 05/02/2023]
Abstract
Pulse oximetry is a ubiquitous optical technology, widely used for diagnosis and treatment guidance. Current pulse oximeters provide indications of arterial oxygen saturation. We present here a new quantitative methodology that extends the capability of pulse oximetry and provides real-time molar concentrations of oxy- and deoxy-hemoglobin at rates of up to 27 Hz by using advanced digital hardware, real-time firmware processing, and ultra-fast optical property calculations with a deep neural network (DNN). The technique utilizes a high-speed frequency domain spectroscopy system with five frequency-multiplexed wavelengths. High-speed demultiplexing and data reduction were performed in firmware. The DNN inversion algorithm was benchmarked as five orders of magnitude faster than conventional iterative methods for optical property extractions. The DNN provided unbiased optical property extractions, with an average error of 0 ± 5.6% in absorption and 0 ± 1.4% in reduced scattering. Together, these improvements enabled the measurement, calculation, and real-time continuous display of hemoglobin concentrations. A proof-of-concept cuff occlusion measurement was performed to demonstrate the ability of the device to track oxy- and deoxy-hemoglobin, and measure quantitative photoplethysmographic changes during the cardiac cycle. This technique substantially extends the capability of pulse oximetry and provides unprecedented real-time non-invasive functional information with broad applicability for cardiopulmonary applications.
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Affiliation(s)
- Yanyu Zhao
- Boston University, Department of Biomedical Engineering, 44 Cummington Mall, Boston, MA 02215, USA
| | - Mattew B. Applegate
- Boston University, Department of Biomedical Engineering, 44 Cummington Mall, Boston, MA 02215, USA
| | - Raeef Istfan
- Boston University, Department of Biomedical Engineering, 44 Cummington Mall, Boston, MA 02215, USA
| | - Ashvin Pande
- Boston University School of Medicine, Section of Cardiovascular Medicine, Boston, MA 02118, USA
| | - Darren Roblyer
- Boston University, Department of Biomedical Engineering, 44 Cummington Mall, Boston, MA 02215, USA
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16
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New insights into the origin of remote PPG signals in visible light and infrared. Sci Rep 2018; 8:8501. [PMID: 29855610 PMCID: PMC5981460 DOI: 10.1038/s41598-018-26068-2] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 05/03/2018] [Indexed: 12/22/2022] Open
Abstract
Remote photoplethysmography (PPG) is an optical measurement technique with established applications in vital signs monitoring. Recently, the consensual understanding of blood volume variations (BVVs) as the origin of PPG signals was challenged, raising validity concerns about the remote SpO2 methodology. Recognizing the imperative for new opto-physiological evidence, this investigation supports the volumetric hypothesis with living skin experiments and Monte Carlo simulations of remote PPG-amplitude in visible light (VIS) and infrared (IR). Multilayered models of the skin were developed to simulate the separate contributions from skin layers containing pulsatile arterioles to the PPG signal in the 450–1000 nm range. The simulated spectra were qualitatively compared with observations of the resting and compressed finger pad, and complemented with videocapillaroscopy. Our results indicate that remote PPG systems indeed probe arterial blood. Green wavelengths probe dermal arterioles while red-IR wavelengths also reach subcutaneous BVVs. Owing to stable penetration depths, the red-IR diagnostic window promotes the invariance of SpO2 measurements to skin non-homogeneities.
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17
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Tinhofer IE, Zaussinger M, Geyer SH, Meng S, Kamolz LP, Tzou CH, Weninger WJ. The dermal arteries in the cutaneous angiosome of the descending genicular artery. J Anat 2018; 232:979-986. [PMID: 29441575 DOI: 10.1111/joa.12792] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/16/2018] [Indexed: 12/12/2022] Open
Abstract
Studies examining thick skin of the thumb pad have challenged the existence of an arterial plexus in the papillary dermis. Instead of a plexus, discrete arterial units, interconnected by arterio-arterial anastomoses, were identified. We hypothesise that the dermal arteries of thin skin are arranged likewise and that there are fewer arterio-arterial anastomoses in the centre of an angiosome than in zones where neighbouring angiosomes overlap. To test these hypotheses, we examined the dermal arteries in the centre of the cutaneous angiosome of the descending genicular artery (DGA) and its zone of overlap with neighbouring angiosomes. Using traditional perfusion techniques, the cutaneous angiosomes of the DGA and the popliteal artery were identified in 11 fresh frozen human lower limbs. Biopsies were harvested from the centre of the cutaneous DGA angiosome and from the zone where neighbouring vascular territories overlapped. Employing high-resolution episcopic microscopy (HREM), digital volume data were generated and the dermal arteries were three-dimensionally reconstructed and examined. In all examined skin areas, the dermal arteries showed tree-like ramifications. The branches of the dermal arteries were connected on average by 1.73 ± 1.01 arterio-arterial anastomoses in the centre of the DGA angiosome and by 3.27 ± 1.27 in the zone where angiosomes overlapped. We demonstrate that discrete but overlapping dermal arterial units with a mean dimension of 1.62 ± 1.34 and 1.80 ± 1.56 mm2 , respectively, supply oxygen and nutrients to the superficial dermis and epidermis of the thin skin of the medial femur. This forms the basis for diagnosing and researching skin pathologies.
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Affiliation(s)
- Ines E Tinhofer
- Division of Anatomy, Centre for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Maximilian Zaussinger
- Division of Anatomy, Centre for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Stefan H Geyer
- Division of Anatomy, Centre for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Stefan Meng
- Division of Anatomy, Centre for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria.,Department of Radiology, Kaiser-Franz-Josef Hospital, Vienna, Austria
| | - Lars-Peter Kamolz
- Division of Plastic, Aesthetic and Reconstructive Surgery, Department of Surgery, Medizinische Universitat Graz, Graz, Austria.,COREMED - Cooperative Centre for Regenerative Medicine, Joanneum Research GmbH, Graz, Austria
| | - Chieh-Han Tzou
- Plastic and Reconstructive Surgery, Department of Surgery, Hospital of the Divine Saviour, Vienna, Austria
| | - Wolfgang J Weninger
- Division of Anatomy, Centre for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
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18
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Chen Z, Rank E, Meiburger KM, Sinz C, Hodul A, Zhang E, Hoover E, Minneman M, Ensher J, Beard PC, Kittler H, Leitgeb RA, Drexler W, Liu M. Non-invasive multimodal optical coherence and photoacoustic tomography for human skin imaging. Sci Rep 2017; 7:17975. [PMID: 29269886 PMCID: PMC5740114 DOI: 10.1038/s41598-017-18331-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 12/08/2017] [Indexed: 12/29/2022] Open
Abstract
The cutaneous vasculature is involved in many diseases. Current clinical examination techniques, however, cannot resolve the human vasculature with all plexus in a non-invasive manner. By combining an optical coherence tomography system with angiography extension and an all optical photoacoustic tomography system, we can resolve in 3D the blood vessels in human skin for all plexus non-invasively. With a customized imaging unit that permits access to various parts of patients' bodies, we applied our multimodality imaging system to investigate several different types of skin conditions. Quantitative vascular analysis is given for each of the dermatological conditions to show the potential diagnostic value of our system in non-invasive examination of diseases and physiological processes. Improved performance of our system over its previous generation is also demonstrated with an updated characterization.
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Affiliation(s)
- Zhe Chen
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, AKH 4L, 1090, Vienna, Austria
| | - Elisabet Rank
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, AKH 4L, 1090, Vienna, Austria
| | - Kristen M Meiburger
- Dipartimento di Elettronica e Telecomunicazioni, Biolab, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129, Torino, Italy
| | - Christoph Sinz
- Department of Dermatology, Medical University of Vienna, Währinger Gürtel 18-20, AKH 7J, 1090, Vienna, Austria
| | - Andreas Hodul
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, AKH 4L, 1090, Vienna, Austria
| | - Edward Zhang
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, WC1E 6BT, London, UK
| | - Erich Hoover
- Insight Photonic Solutions, Inc., 2650 Crescent Drive, Number 201, Lafayette, CO, 80026, USA
| | - Micheal Minneman
- Insight Photonic Solutions, Inc., 2650 Crescent Drive, Number 201, Lafayette, CO, 80026, USA
| | - Jason Ensher
- Insight Photonic Solutions, Inc., 2650 Crescent Drive, Number 201, Lafayette, CO, 80026, USA
| | - Paul C Beard
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, WC1E 6BT, London, UK
| | - Harald Kittler
- Department of Dermatology, Medical University of Vienna, Währinger Gürtel 18-20, AKH 7J, 1090, Vienna, Austria
| | - Rainer A Leitgeb
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, AKH 4L, 1090, Vienna, Austria
| | - Wolfgang Drexler
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, AKH 4L, 1090, Vienna, Austria
| | - Mengyang Liu
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, AKH 4L, 1090, Vienna, Austria.
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19
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Geyer SH, Maurer-Gesek B, Reissig LF, Weninger WJ. High-resolution Episcopic Microscopy (HREM) - Simple and Robust Protocols for Processing and Visualizing Organic Materials. J Vis Exp 2017. [PMID: 28715372 PMCID: PMC5609318 DOI: 10.3791/56071] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
We provide simple protocols for generating digital volume data with the high-resolution episcopic microscopy (HREM) method. HREM is capable of imaging organic materials with volumes up to 5 x 5 x 7 mm3 in typical numeric resolutions between 1 x 1 x 1 and 5 x 5 x 5 µm3. Specimens are embedded in methacrylate resin and sectioned on a microtome. After each section an image of the block surface is captured with a digital video camera that sits on the phototube connected to the compound microscope head. The optical axis passes through a green fluorescent protein (GFP) filter cube and is aligned with a position, at which the bock holder arm comes to rest after each section. In this way, a series of inherently aligned digital images, displaying subsequent block surfaces are produced. Loading such an image series in three-dimensional (3D) visualization software facilitates the immediate conversion to digital volume data, which permit virtual sectioning in various orthogonal and oblique planes and the creation of volume and surface rendered computer models. We present three simple, tissue specific protocols for processing various groups of organic specimens, including mouse, chick, quail, frog and zebra fish embryos, human biopsy material, uncoated paper and skin replacement material.
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Affiliation(s)
- Stefan H Geyer
- Division of Anatomy, Center for Anatomy and Cell Biology & MIC, Medical University of Vienna
| | - Barbara Maurer-Gesek
- Division of Anatomy, Center for Anatomy and Cell Biology & MIC, Medical University of Vienna
| | - Lukas F Reissig
- Division of Anatomy, Center for Anatomy and Cell Biology & MIC, Medical University of Vienna
| | - Wolfgang J Weninger
- Division of Anatomy, Center for Anatomy and Cell Biology & MIC, Medical University of Vienna;
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20
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Liu M, Chen Z, Zabihian B, Sinz C, Zhang E, Beard PC, Ginner L, Hoover E, Minneman MP, Leitgeb RA, Kittler H, Drexler W. Combined multi-modal photoacoustic tomography, optical coherence tomography (OCT) and OCT angiography system with an articulated probe for in vivo human skin structure and vasculature imaging. BIOMEDICAL OPTICS EXPRESS 2016; 7:3390-3402. [PMID: 27699106 PMCID: PMC5030018 DOI: 10.1364/boe.7.003390] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 07/28/2016] [Accepted: 08/09/2016] [Indexed: 05/05/2023]
Abstract
Cutaneous blood flow accounts for approximately 5% of cardiac output in human and plays a key role in a number of a physiological and pathological processes. We show for the first time a multi-modal photoacoustic tomography (PAT), optical coherence tomography (OCT) and OCT angiography system with an articulated probe to extract human cutaneous vasculature in vivo in various skin regions. OCT angiography supplements the microvasculature which PAT alone is unable to provide. Co-registered volumes for vessel network is further embedded in the morphologic image provided by OCT. This multi-modal system is therefore demonstrated as a valuable tool for comprehensive non-invasive human skin vasculature and morphology imaging in vivo.
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Affiliation(s)
- Mengyang Liu
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, AKH 4L, Vienna, 1090, Austria
| | - Zhe Chen
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, AKH 4L, Vienna, 1090, Austria
| | - Behrooz Zabihian
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, AKH 4L, Vienna, 1090, Austria
| | - Christoph Sinz
- Department of Dermatology, Medical University of Vienna, Währinger Gürtel 18-20, AKH 7J, Vienna, 1090, Austria
| | - Edward Zhang
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, UK
| | - Paul C. Beard
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, UK
| | - Laurin Ginner
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, AKH 4L, Vienna, 1090, Austria
| | - Erich Hoover
- INSIGHT Photonic Solutions, Inc., 300 S. Public Road, Lafayette, CO, 80026, USA
| | - Micheal P. Minneman
- INSIGHT Photonic Solutions, Inc., 300 S. Public Road, Lafayette, CO, 80026, USA
| | - Rainer A. Leitgeb
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, AKH 4L, Vienna, 1090, Austria
| | - Harald Kittler
- Department of Dermatology, Medical University of Vienna, Währinger Gürtel 18-20, AKH 7J, Vienna, 1090, Austria
| | - Wolfgang Drexler
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, AKH 4L, Vienna, 1090, Austria
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21
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Wong R, Geyer S, Weninger W, Guimberteau JC, Wong JK. The dynamic anatomy and patterning of skin. Exp Dermatol 2015; 25:92-8. [PMID: 26284579 DOI: 10.1111/exd.12832] [Citation(s) in RCA: 175] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/12/2015] [Indexed: 12/14/2022]
Abstract
The skin is often viewed as a static barrier that protects the body from the outside world. Emphasis on studying the skin's architecture and biomechanics in the context of restoring skin movement and function is often ignored. It is fundamentally important that if skin is to be modelled or developed, we do not only focus on the biology of skin but also aim to understand its mechanical properties and structure in living dynamic tissue. In this review, we describe the architecture of skin and patterning seen in skin as viewed from a surgical perspective and highlight aspects of the microanatomy that have never fully been realized and provide evidence or concepts that support the importance of studying living skin's dynamic behaviour. We highlight how the structure of the skin has evolved to allow the body dynamic form and function, and how injury, disease or ageing results in a dramatic changes to the microarchitecture and changes physical characteristics of skin. Therefore, appreciating the dynamic microanatomy of skin from the deep fascia through to the skin surface is vitally important from a dermatological and surgical perspective. This focus provides an alternative perspective and approach to addressing skin pathologies and skin ageing.
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Affiliation(s)
- Richard Wong
- Plastic Surgery Research, Centre of Dermatology, University of Manchester, Manchester, UK
| | - Stefan Geyer
- Center for Anatomy & Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Weninger
- Center for Anatomy & Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Jean-Claude Guimberteau
- De la Main et Plastique Reconstructice, Institut Aquitain de la Main Bordeaux, Pessac, France
| | - Jason K Wong
- Plastic Surgery Research, Centre of Dermatology, University of Manchester, Manchester, UK
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22
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Wiedner M, Tinhofer IE, Kamolz LP, Seyedian Moghaddam A, Justich I, Liegl-Atzwanger B, Bubalo V, Weninger WJ, Lumenta DB. Simultaneous dermal matrix and autologous split-thickness skin graft transplantation in a porcine wound model: a three-dimensional histological analysis of revascularization. Wound Repair Regen 2015; 22:749-54. [PMID: 25358670 DOI: 10.1111/wrr.12233] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Accepted: 09/04/2014] [Indexed: 01/01/2023]
Abstract
Despite the popularity of a simultaneous application of dermal matrices and split-thickness skin grafts, scarce evidence exists about the process of revascularization involved. In this study, we aimed at analyzing the progression of revascularization by high-resolution episcopic microscopy (HREM) in a porcine excisional wound model. Following the surgical procedure creating 5 × 5 cm(2) full-thickness defects on the back, one area was covered with an autologous split-thickness skin graft alone (control group), the other with a collagen-elastin dermal matrix plus split-thickness skin graft (dermal matrix group). Two skin biopsies per each group and location were performed on day 5, 10, 15, and 28 postoperatively and separately processed for H&E as well as HREM. The dermal layer was thicker in the dermal matrix group vs. control on day 5 and 28. No differences were found for revascularization by conventional histology. In HREM, the dermal matrix did not appear to decelerate the revascularization process. The presence of the dermal matrix could be distinguished until day 15. By day 28, the structure of the dermal matrix could no longer be delineated and was replaced by autologous tissue. As assessed by conventional histology and confirmed by HREM, the revascularization process was comparable in both groups, notably with regard to the vertical ingrowth of sprouting vessels. The presented technique of HREM is a valuable addition for analyzing small vessel sprouting in dermal matrices in the future.
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Affiliation(s)
- Maria Wiedner
- Research Unit for Tissue Regeneration, Repair, and Reconstruction, Division of Plastic, Aesthetic, and Reconstructive Surgery, Department of Surgery, Medical University of Graz, Graz, Austria
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23
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High-resolution episcopic microscopy (HREM): A useful technique for research in wound care. Ann Anat 2015; 197:3-10. [DOI: 10.1016/j.aanat.2014.10.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 09/24/2014] [Accepted: 10/13/2014] [Indexed: 12/15/2022]
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24
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Geyer SH, Nöhammer MM, Mathä M, Reissig L, Tinhofer IE, Weninger WJ. High-resolution episcopic microscopy (HREM): a tool for visualizing skin biopsies. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2014; 20:1356-64. [PMID: 25198556 DOI: 10.1017/s1431927614013063] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
We evaluate the usefulness of digital volume data produced with the high-resolution episcopic microscopy (HREM) method for visualizing the three-dimensional (3D) arrangement of components of human skin, and present protocols designed for processing skin biopsies for HREM data generation. A total of 328 biopsies collected from normally appearing skin and from a melanocytic nevus were processed. Cuboidal data volumes with side lengths of ~2×3×6 mm3 and voxel sizes of 1.07×1.07×1.5 µm3 were produced. HREM data fit ideally for visualizing the epidermis at large, and for producing highly detailed volume and surface-rendered 3D representations of the dermal and hypodermal components at a structural level. The architecture of the collagen fiber bundles and the spatial distribution of nevus cells can be easily visualized with volume-rendering algorithms. We conclude that HREM has great potential to serve as a routine tool for researching and diagnosing skin pathologies.
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Affiliation(s)
- Stefan H Geyer
- 1MRC National Institute for Medical Research,London,NW7 1AA,UK
| | - Maria M Nöhammer
- 2Centre for Anatomy and Cell Biology,Medical University of Vienna,Waehringer Street 13,A-1090 Vienna,Austria
| | - Markus Mathä
- 2Centre for Anatomy and Cell Biology,Medical University of Vienna,Waehringer Street 13,A-1090 Vienna,Austria
| | - Lukas Reissig
- 2Centre for Anatomy and Cell Biology,Medical University of Vienna,Waehringer Street 13,A-1090 Vienna,Austria
| | - Ines E Tinhofer
- 2Centre for Anatomy and Cell Biology,Medical University of Vienna,Waehringer Street 13,A-1090 Vienna,Austria
| | - Wolfgang J Weninger
- 2Centre for Anatomy and Cell Biology,Medical University of Vienna,Waehringer Street 13,A-1090 Vienna,Austria
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