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Hof S, Untiedt H, Hübner A, Marcus C, Kuebart A, Herminghaus A, Vollmer C, Bauer I, Picker O, Truse R. Effects of remote ischemic preconditioning on early markers of intestinal injury in experimental hemorrhage in rats. Sci Rep 2024; 14:12960. [PMID: 38839819 PMCID: PMC11153647 DOI: 10.1038/s41598-024-63293-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 05/27/2024] [Indexed: 06/07/2024] Open
Abstract
The maintenance of intestinal integrity and barrier function under conditions of restricted oxygen availability is crucial to avoid bacterial translocation and local inflammation. Both lead to secondary diseases after hemorrhagic shock and might increase morbidity and mortality after surviving the initial event. Monitoring of the intestinal integrity especially in the early course of critical illness remains challenging. Since microcirculation and mitochondrial respiration are main components of the terminal stretch of tissue oxygenation, the evaluation of microcirculatory and mitochondrial variables could identify tissues at risk during hypoxic challenges, indicate an increase of intestinal injury, and improve our understanding of regional pathophysiology during acute hemorrhage. Furthermore, improving intestinal microcirculation or mitochondrial respiration, e.g. by remote ischemic preconditioning (RIPC) that was reported to exert a sufficient tissue protection in various tissues and was linked to mediators with vasoactive properties could maintain intestinal integrity. In this study, postcapillary oxygen saturation (µHbO2), microvascular flow index (MFI) and plasmatic D-lactate concentration revealed to be early markers of intestinal injury in a rodent model of experimental hemorrhagic shock. Mitochondrial function was not impaired in this experimental model of acute hemorrhage. Remote ischemic preconditioning (RIPC) failed to improve intestinal microcirculation and intestinal damage during hemorrhagic shock.
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Affiliation(s)
- Stefan Hof
- Department of Anesthesiology, University Hospital Düsseldorf, Düsseldorf, Germany.
| | - Hendrik Untiedt
- Department of Anesthesiology, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Anne Hübner
- Department of Anesthesiology, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Carsten Marcus
- Department of Anesthesiology, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Anne Kuebart
- Department of Anesthesiology, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Anna Herminghaus
- Department of Anesthesiology, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Christian Vollmer
- Department of Anesthesiology, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Inge Bauer
- Department of Anesthesiology, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Olaf Picker
- Department of Anesthesiology, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Richard Truse
- Department of Anesthesiology, University Hospital Düsseldorf, Düsseldorf, Germany
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Nakabayashi M, Tanabe J, Ogura Y, Ichinose M, Shibagaki Y, Kamijo-Ikemori A, Ono Y. Correlation of diabetic renal hypoperfusion with microvascular responses of the skeletal muscle: a rat model study using diffuse correlation spectroscopy. BIOMEDICAL OPTICS EXPRESS 2024; 15:3900-3913. [PMID: 38867789 PMCID: PMC11166419 DOI: 10.1364/boe.522385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 05/10/2024] [Accepted: 05/12/2024] [Indexed: 06/14/2024]
Abstract
Using diffuse correlation spectroscopy, we assessed the renal blood flow and thigh muscle microvascular responses in a rat model of type 2 diabetes. The blood flow index at the renal surface decreased significantly with arterial clamping, cardiac extirpation, and the progression of diabetic endothelial dysfunction. Renal blood flow measured in diabetic and nondiabetic rats also showed a significant correlation with the reactive hyperemic response of the thigh muscle. These results suggest shared microcirculatory dysfunction in the kidney and skeletal muscle and support endothelial responses in the skeletal muscle as a potential noninvasive biomarker of renal hypoperfusion.
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Affiliation(s)
- Mikie Nakabayashi
- Electrical Engineering Program, Graduate School of Science and Technology, Meiji University, 1-1-1 Higashi-Mita, Tama-ku, Kawasaki, Kanagawa 2148571, Japan
| | - Jun Tanabe
- Division of Nephrology and hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa 2168511, Japan
| | - Yuji Ogura
- Department of Physiology, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa 2168511, Japan
| | - Masashi Ichinose
- Human Integrative Physiology Laboratory, School of Business Administration, Meiji University, 1-1 Surugadai, Kanda, Chiyoda-ku Tokyo 1018301, Japan
| | - Yugo Shibagaki
- Division of Nephrology and hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa 2168511, Japan
| | - Atsuko Kamijo-Ikemori
- Division of Nephrology and hypertension, Department of Internal Medicine, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa 2168511, Japan
- Department of Anatomy, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa 2168511, Japan
| | - Yumie Ono
- Department of Electronics and Bioinformatics, School of Science and Technology, Meiji University, 1-1-1 Higashi-Mita, Tama-ku, Kawasaki, Kanagawa 2148571, Japan
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Berkowitz BA, Paruchuri A, Stanek J, Abdul-Nabi M, Podolsky RH, Bustos AH, Childers KL, Murphy GG, Stangis K, Roberts R. Biomarker evidence of early vision and rod energy-linked pathophysiology benefits from very low dose DMSO in 5xFAD mice. Acta Neuropathol Commun 2024; 12:85. [PMID: 38822433 PMCID: PMC11140992 DOI: 10.1186/s40478-024-01799-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Accepted: 05/20/2024] [Indexed: 06/03/2024] Open
Abstract
Here, we test whether early visual and OCT rod energy-linked biomarkers indicating pathophysiology in nicotinamide nucleotide transhydrogenase (Nnt)-null 5xFAD mice also occur in Nnt-intact 5xFAD mice and whether these biomarkers can be pharmacologically treated. Four-month-old wild-type or 5xFAD C57BL/6 substrains with either a null (B6J) Nnt or intact Nnt gene (B6NTac) and 5xFAD B6J mice treated for one month with either R-carvedilol + vehicle or only vehicle (0.01% DMSO) were studied. The contrast sensitivity (CS), external limiting membrane-retinal pigment epithelium (ELM-RPE) thickness (a proxy for low pH-triggered water removal), profile shape of the hyperreflective band just posterior to the ELM (i.e., the mitochondrial configuration within photoreceptors per aspect ratio [MCP/AR]), and retinal laminar thickness were measured. Both wild-type substrains showed similar visual performance indices and dark-evoked ELM-RPE contraction. The lack of a light-dark change in B6NTac MCP/AR, unlike in B6J mice, is consistent with relatively greater mitochondrial efficiency. 5xFAD B6J mice, but not 5xFAD B6NTac mice, showed lower-than-WT CS. Light-adapted 5xFAD substrains both showed abnormal ELM-RPE contraction and greater-than-WT MCP/AR contraction. The inner retina and superior outer retina were thinner. Treating 5xFAD B6J mice with R-carvedilol + DMSO or DMSO alone corrected CS and ELM-RPE contraction but not supernormal MCP/AR contraction or laminar thinning. These results provide biomarker evidence for prodromal photoreceptor mitochondrial dysfunction/oxidative stress/oxidative damage, which is unrelated to visual performance, as well as the presence of the Nnt gene. This pathophysiology is druggable in 5xFAD mice.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI, 48201, USA.
| | - Anuhya Paruchuri
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI, 48201, USA
| | - Josh Stanek
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI, 48201, USA
| | - Mura Abdul-Nabi
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI, 48201, USA
| | - Robert H Podolsky
- Biostatistics and Study Methodology, Children's National Hospital, Silver Spring, MD, USA
| | | | | | - Geoffrey G Murphy
- Department of Molecular and Integrative Physiology, Molecular Behavioral Neuroscience Institute, University of Michigan Medical School, Ann Arbor, MI, USA
- Michigan Neuroscience Institute, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Katherine Stangis
- Michigan Neuroscience Institute, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Robin Roberts
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI, 48201, USA
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Abousy M, Drew-Bear LE, Gibbons A, Pan-Doh N, Li X, Handa JT. In-Depth Analysis of Preoperative OCT Markers as Prognostic Factors for Lamellar Macular Holes and Epiretinal Membrane Foveoschisis. Ophthalmol Retina 2024; 8:465-472. [PMID: 37972892 PMCID: PMC11070309 DOI: 10.1016/j.oret.2023.10.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 10/23/2023] [Accepted: 10/27/2023] [Indexed: 11/19/2023]
Abstract
OBJECTIVE To identify preoperative OCT markers that correlate with postoperative visual acuity (VA) changes in eyes with lamellar macular hole (LMH) and epiretinal membrane foveoschisis (ERMF) after pars plana vitrectomy (PPV). DESIGN Cross-sectional retrospective study. SUBJECTS Patients seen at the Wilmer Eye Institute between 2011 and 2021 with an International Classification of Diseases, Ninth Revision, or International Classification of Diseases, 10th Revision, code for "macular hole" that underwent PPV, and demonstrated all OCT criteria present for either LMH or ERMF based on the Hubschman et al (2020) classification. METHODS OCT markers including hole dimensions, retinal layer continuity, and ellipsoid zone (EZ) convexity and pixelated intensity were quantified. Visual acuity immediately before PPV and at the last follow-up date available were both recorded. MAIN OUTCOME MEASURES Preoperative OCT variables that are correlated with postoperative changes in VA. RESULTS Forty-two eyes from 42 patients with LMH (n = 11) and ERMF (n = 31) that underwent PPV were identified. Visual acuity in the ERMF cohort significantly improved at last follow-up compared with preoperative VA (P < 0.001), whereas VA in the LMH cohort did not (P = 0.14). In the LMH cohort, retinal layer continuity at the hole edge was positively correlated with change in VA at final follow-up, whereas hole height was negatively correlated with VA. In the ERMF cohort, preoperative VA was negatively correlated with change in VA at final follow-up. CONCLUSIONS Retinal layer continuity at the hole and hole height are novel preoperative markers that predict postoperative VA change in LMH. After identifying the type of macular lesion, surgeons should consider using these preoperative OCT markers when counseling patients on potential postoperative VA outcomes and when managing patient expectations. FINANCIAL DISCLOSURE(S) The authors have no proprietary or commercial interest in any materials discussed in this article.
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Affiliation(s)
- Mya Abousy
- Bascom Palmer Eye Institute, University of Miami, Miami, Florida; Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Laura E Drew-Bear
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland; University of Missouri-Kansas City Department of Ophthalmology, Kansas City, Missouri
| | - Alison Gibbons
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Nathan Pan-Doh
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Ximin Li
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - James T Handa
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland.
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Kuebart A, Gross K, Maicher C, Sonnenschein M, Raupach A, Schulz J, Truse R, Hof S, Marcus C, Vollmer C, Bauer I, Picker O, Relja B, Herminghaus A. Gemfibrozil Improves Microcirculatory Oxygenation of Colon and Liver without Affecting Mitochondrial Function in a Model of Abdominal Sepsis in Rats. Int J Mol Sci 2023; 25:262. [PMID: 38203431 PMCID: PMC10778839 DOI: 10.3390/ijms25010262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/15/2023] [Accepted: 12/21/2023] [Indexed: 01/12/2024] Open
Abstract
Recent studies observed, despite an anti-hyperlipidaemic effect, a positive impact of fibrates on septic conditions. This study evaluates the effects of gemfibrozil on microcirculatory variables, mitochondrial function, and lipid peroxidation levels with regard to its potential role as an indicator for oxidative stress in the colon and liver under control and septic conditions and dependencies on PPARα-mediated mechanisms of action. With the approval of the local ethics committee, 120 Wistar rats were randomly divided into 12 groups. Sham and septic animals were treated with a vehicle, gemfibrozil (30 and 100 mg/kg BW), GW 6471 (1 mg/kg BW, PPARα inhibitor), or a combination of both drugs. Sepsis was induced via the colon ascendens stent peritonitis (CASP) model. Then, 24 h post sham or CASP surgery, a re-laparotomy was performed. Measures of vital parameters (heart rate (HR), mean arterial pressure (MAP), and microcirculation (µHbO2)) were recorded for 90 min. Mitochondrial respirometry and assessment of lipid peroxidation via a malondialdehyde (MDA) assay were performed on colon and liver tissues. In the untreated sham animals, microcirculation remained stable, while pre-treatment with gemfibrozil showed significant decreases in the microcirculatory oxygenation of the colon. In the CASP animals, µHbO2 levels in the colon and the liver were significantly decreased 90 min after laparotomy. Pre-treatment with gemfibrozil prevented the microcirculatory aberrations in both organs. Gemfibrozil did not affect mitochondrial function and lipid peroxidation levels in the sham or CASP animals. Gemfibrozil treatment influences microcirculation depending on the underlying condition. Gemfibrozil prevents sepsis-induced microcirculatory aberrances in the colon and liver PPARα-independently. In non-septic animals, gemfibrozil impairs the microcirculatory variables in the colon without affecting those in the liver.
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Affiliation(s)
- Anne Kuebart
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstrasse 5, 40225 Duesseldorf, Germany; (A.K.)
| | - Katharina Gross
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstrasse 5, 40225 Duesseldorf, Germany; (A.K.)
| | - Charlotte Maicher
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstrasse 5, 40225 Duesseldorf, Germany; (A.K.)
| | - Max Sonnenschein
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstrasse 5, 40225 Duesseldorf, Germany; (A.K.)
| | - Annika Raupach
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstrasse 5, 40225 Duesseldorf, Germany; (A.K.)
| | - Jan Schulz
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstrasse 5, 40225 Duesseldorf, Germany; (A.K.)
| | - Richard Truse
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstrasse 5, 40225 Duesseldorf, Germany; (A.K.)
| | - Stefan Hof
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstrasse 5, 40225 Duesseldorf, Germany; (A.K.)
| | - Carsten Marcus
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstrasse 5, 40225 Duesseldorf, Germany; (A.K.)
| | - Christian Vollmer
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstrasse 5, 40225 Duesseldorf, Germany; (A.K.)
| | - Inge Bauer
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstrasse 5, 40225 Duesseldorf, Germany; (A.K.)
| | - Olaf Picker
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstrasse 5, 40225 Duesseldorf, Germany; (A.K.)
| | - Borna Relja
- Department of Trauma, Hand, Plastic and Reconstructive Surgery, Translational and Experimental Trauma Research, University Hospital Ulm, Ulm University, Albert-Einstein-Allee 23, 89081 Ulm, Germany
| | - Anna Herminghaus
- Department of Anesthesiology, University Hospital Duesseldorf, Moorenstrasse 5, 40225 Duesseldorf, Germany; (A.K.)
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Berkowitz BA, Podolsky RH, Childers KL, Roberts R, Waseem R. Multiple Bioenergy-Linked OCT Biomarkers Suggest Greater-Than-Normal Rod Mitochondria Activity Early in Experimental Alzheimer's Disease. Invest Ophthalmol Vis Sci 2023; 64:12. [PMID: 36867132 PMCID: PMC9988708 DOI: 10.1167/iovs.64.3.12] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023] Open
Abstract
Purpose In Alzheimer's disease, central brain neurons show evidence for early hyperactivity. It is unclear if this occurs in the retina, another disease target. Here, we tested for imaging biomarker manifestation of prodromal hyperactivity in rod mitochondria in vivo in experimental Alzheimer's disease. Methods Light- and dark-adapted 4-month-old 5xFAD and wild-type (WT) mice, both on a C57BL/6J background, were studied with optical coherence tomography (OCT). We measured the reflectivity profile shape of the inner segment ellipsoid zone (EZ) as a proxy for mitochondria distribution. Two additional indices responsive to mitochondria activity were also measured: the thickness of the external limiting membrane-retinal pigment epithelium (ELM-RPE) region and the signal magnitude of a hyporeflective band (HB) between photoreceptor tips and apical RPE. Retinal laminar thickness and visual performance were evaluated. Results In response to low energy demand (light), WT mice showed the expected elongation in EZ reflectivity profile shape, relatively thicker ELM-RPE, and greater HB signal. Under high energy demand (dark), the EZ reflectivity profile shape was rounder, the ELM-RPE was thinner, and the HB was reduced. These OCT biomarker patterns for light-adapted 5xFAD mice did not match those of light-adapted WT mice but rather that of dark-adapted WT mice. Dark-adapted 5xFAD and WT mice showed the same biomarker pattern. The 5xFAD mice exhibited modest nuclear layer thinning and lower-than-normal contrast sensitivity. Conclusions Results from three OCT bioenergy biomarkers raise the novel possibility of early rod hyperactivity in vivo in a common Alzheimer's disease model.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Robert H Podolsky
- Biostatistics and Study Methodology, Children's National Hospital, Silver Spring, Maryland, United States
| | - Karen L Childers
- Beaumont Research Institute, Beaumont Health, Royal Oak, Michigan, United States
| | - Robin Roberts
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Rida Waseem
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
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Algieri C, Blanco-Prieto O, Llavanera M, Yeste M, Spinaci M, Mari G, Bucci D, Nesci S. Effects of cryopreservation on the mitochondrial bioenergetics of bovine sperm. Reprod Domest Anim 2023; 58:184-188. [PMID: 36107136 PMCID: PMC10092266 DOI: 10.1111/rda.14261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 09/12/2022] [Accepted: 09/13/2022] [Indexed: 01/07/2023]
Abstract
This study evaluated the bioenergetic map of mitochondria metabolism in cryopreserved bovine sperm. The detected oligomycin-sensitive basal respiration supported ATP production; frozen-thawed spermatozoa were found to have a coupling efficiency higher than 0.80. Cell respiration, however, was not stimulated by the protonophoric action of FCCP, as its titration with 1, 2, 4 and 6 μM did not stimulate the uncoupling activity on oxidative phosphorylation as highlighted by unresponsive oxygen consumption. The unusual effect on the stimulation of maximal respiration was not related to fibronectin- or PDL-coated plates used for cellular metabolism analysis. Conversely, irradiation of frozen-thawed bovine sperm with the red light improved mitochondrial parameters. In effect, the maximal respiration of red-light-stimulated sperm in PDL-coated plates was higher than the non-irradiated. In spite of this, red-light irradiation had no impact on membrane integrity and mitochondrial activity evaluated by epifluorescence microscopy.
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Affiliation(s)
- Cristina Algieri
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - Olga Blanco-Prieto
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - Marc Llavanera
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy.,Biotechnology of Animal and Human Reproduction (TechnoSperm), Unit of Cell Biology, Department of Biology, Faculty of Sciences, Institute of Food and Agricultural Technology, University of Girona, Girona, Spain
| | - Marc Yeste
- Biotechnology of Animal and Human Reproduction (TechnoSperm), Unit of Cell Biology, Department of Biology, Faculty of Sciences, Institute of Food and Agricultural Technology, University of Girona, Girona, Spain.,Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
| | - Marcella Spinaci
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - Gaetano Mari
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy.,National Institute for Artificial Insemination-AUB INFA, University of Bologna, Bologna, Spain
| | - Diego Bucci
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
| | - Salvatore Nesci
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, Bologna, Italy
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Natural History of the Relative Ellipsoid Zone Reflectivity in Age-Related Macular Degeneration. Ophthalmol Retina 2022; 6:1165-1172. [PMID: 35709960 DOI: 10.1016/j.oret.2022.06.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 05/08/2022] [Accepted: 06/06/2022] [Indexed: 01/06/2023]
Abstract
PURPOSE Relative ellipsoid zone reflectivity (rEZR) has been reported to be reduced in intermediate age-related macular degeneration (iAMD). However, longitudinal changes in rEZR remain unknown. This study investigated the natural history of rEZR in iAMD and its association with risk factors for disease progression, including the presence or extent of drusen volume, reticular pseudodrusen (RPD), and pigmentary abnormalities (PAs). DESIGN Longitudinal observational study. PARTICIPANTS Subjects with bilateral large drusen. METHODS Spectral-domain (SD) OCT images of both eyes from each participant were obtained every 6 months for 3 years. Using an automated rEZR determination approach, the average rEZR of the central 20° macula was determined for each SD-OCT volume scan. Linear mixed models were used to determine the rate of change in rEZR with age (using the cross-sectional data at baseline) and over time (longitudinal data) and the interactions between the rate of rEZR changes with AMD risk factors at baseline. MAIN OUTCOME MEASURES Relative ellipsoid zone reflectivity and its rate of change with age and over time. RESULTS A total of 280 eyes from 140 individuals with bilateral large drusen were included in this study. Cross-sectional data showed that rEZR reduced with increasing age (-8.4 arbitrary units [AUs] per decade; 95% confidence interval [CI], -11.5 to -5.2; P < 0.001). Longitudinal data showed that, on average, rEZR declined at a rate of -2.1 AU per year (95% CI, -2.6 to -1.6 AU per year; P < 0.001). Larger RPD area (P = 0.042) at baseline was associated with a faster rate of rEZR decline over time, whereas the presence of PAs and the drusen volume at baseline showed no significant association with rEZR decline over time (P = 0.068 and P = 0.529, respectively). CONCLUSIONS The rEZR significantly reduces over 3 years in subjects with iAMD, and both the presence and increasing extent of coexistent RPD at baseline are associated with a faster rate of decline. These findings warrant further studies to understand the value of rEZR as a biomarker of AMD progression.
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Berkowitz BA, Podolsky RH, Childers KL, Burgoyne T, De Rossi G, Qian H, Roberts R, Katz R, Waseem R, Goodman C. Functional Changes Within the Rod Inner Segment Ellipsoid in Wildtype Mice: An Optical Coherence Tomography and Electron Microscopy Study. Invest Ophthalmol Vis Sci 2022; 63:8. [PMID: 35816042 PMCID: PMC9284466 DOI: 10.1167/iovs.63.8.8] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Purpose To test the hypothesis that changing energy needs alter mitochondria distribution within the rod inner segment ellipsoid. Methods In mice with relatively smaller (C57BL/6J [B6J]) or greater (129S6/ev [S6]) retina mitochondria maximum reserve capacity, the profile shape of the rod inner segment ellipsoid zone (ISez) was measured with optical coherence tomography (OCT) under higher (dark) or lower (light) energy demand conditions. ISez profile shape was characterized using an unbiased ellipse descriptor (minor/major aspect ratio). Other bioenergy indexes evaluated include the external limiting membrane-retinal pigment epithelium (ELM-RPE) thickness and the magnitude of the signal intensity of a hyporeflective band located between the photoreceptor tips and apical RPE. The spatial distribution of rod ellipsoid mitochondria were also examined with electron microscopy. Results In B6J mice, darkness produced a greater ISez aspect ratio, thinner ELM-RPE, and a smaller hyporeflective band intensity than in light. In S6 mice, dark and light ISez aspect ratio values were not different and were greater than in light-adapted B6J mice; dark-adapted S6 mice showed smaller ELM-RPE thinning versus light, and negligible hyporeflective band intensity in the light. In B6J mice, mitochondria number in light increased in the distal inner segment ellipsoid and decreased proximally. In S6 mice, mitochondria number in the inner segment ellipsoid were not different between light and dark, and were greater than in B6J mice. Conclusions These data raise the possibility that rod mitochondria activity in mice can be noninvasively evaluated based on the ISez profile shape, a new OCT index that complements OCT energy biomarkers measured outside of the ISez region.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Robert H Podolsky
- Biostatistics and Study Methodology, Children's National Hospital, Silver Spring, Maryland, United States
| | - Karen Lins Childers
- Beaumont Research Institute, Beaumont Health, Royal Oak, Michigan, Unites States
| | - Tom Burgoyne
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Giulia De Rossi
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Haohua Qian
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland, Unites States
| | - Robin Roberts
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Ryan Katz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Rida Waseem
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Cole Goodman
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
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Ramadan KT, McFadden C, Gomes B, Schwiegelshohn F, Ribeiro RVP, Chan HHL, Betz V, Cypel M, Lilge L. Determination of Optical Properties and Photodynamic Threshold of Lung Tissue for Treatment Planning of In Vivo Lung Perfusion Assisted Photodynamic Therapy. Photodiagnosis Photodyn Ther 2021; 35:102353. [PMID: 34048969 DOI: 10.1016/j.pdpdt.2021.102353] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 05/03/2021] [Accepted: 05/21/2021] [Indexed: 11/17/2022]
Abstract
BACKGROUND Isolated lung metastases in sarcoma and colorectal cancer patients are inadequately treated with current standard therapies. In Vivo Lung Perfusion, a novel platform, could overcome limitations to photodynamic therapy treatment volumes by using low cellular perfusate, removing blood, theoretically allowing greater light penetration. To develop personalized photodynamic therapy protocols requires in silico light propagation simulations based on optical properties and maximal permissible photodynamic threshold dose of lung tissue. This study presents quantification of optical properties for two perfusates and the photodynamic threshold for 5-ALA and Chlorin e6. METHODS Porcine and human lungs were placed on Ex Vivo Lung Perfusion, and perfused with acellular solution or blood. Isotropic diffusers were placed within bronchi and on lung surface for light transmission measurements, from which absorption and light scattering properties were calculated at multiple wavelengths. Separately, pigs were injected with 5-ALA or Chlorin e6, and lung tissue was irradiated at increasing doses. Resultant lesion sizes were measured by CT and histology to quantify the photodynamic threshold. RESULTS Low cellular perfusate reduced the tissue absorption coefficient significantly, increasing penetration depth of light by 3.3 mm and treatment volumes 3-fold. The photodynamic threshold for lung exposed to 5-ALA was consistent with other malignancies. Chlorin e6 levels were undetectable in lung tissue and did not demonstrate photodynamic-induced necrosis. CONCLUSIONS Light penetration with low cellular perfusate is significantly greater and could enable treatments for diffuse disease. This data aids photodynamic treatment planning and will guide clinical translation of photodynamic therapy protocols in the lung, especially during lung perfusion.
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Affiliation(s)
- Khaled T Ramadan
- University of Toronto, Faculty of Medicine, Department of Surgery, 149 College Street, Toronto M5T 1P5, Ontario, Canada
| | - Christopher McFadden
- University of Toronto, Faculty of Medicine, Department of Medical Biophysics, 101 College Street, Toronto M5G 1L7, Ontario, Canada
| | - Bruno Gomes
- Princess Margaret Cancer Centre, University Health Network, 101 College St, Toronto M5G 2C4, Ontario, Canada
| | - Fynn Schwiegelshohn
- University of Toronto, Faculty of Applied Science and Engineering, Department of Electrical and Computer Engineering, 10 Kings College Road, Toronto M5S 3G4, Ontario, Canada
| | - Rafaela V P Ribeiro
- Princess Margaret Cancer Centre, University Health Network, 101 College St, Toronto M5G 2C4, Ontario, Canada
| | - Harley H L Chan
- Techna Institute, Guided Therapeutics Program, University Health Network, 101 College Street, Toronto M5G 1L7, Ontario, Canada
| | - Vaughn Betz
- University of Toronto, Faculty of Applied Science and Engineering, Department of Electrical and Computer Engineering, 10 Kings College Road, Toronto M5S 3G4, Ontario, Canada
| | - Marcelo Cypel
- University of Toronto, Faculty of Medicine, Department of Surgery, 149 College Street, Toronto M5T 1P5, Ontario, Canada; Princess Margaret Cancer Centre, University Health Network, 101 College St, Toronto M5G 2C4, Ontario, Canada
| | - Lothar Lilge
- University of Toronto, Faculty of Medicine, Department of Medical Biophysics, 101 College Street, Toronto M5G 1L7, Ontario, Canada; Princess Margaret Cancer Centre, University Health Network, 101 College St, Toronto M5G 2C4, Ontario, Canada.
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11
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Thiele S, Isselmann B, Pfau M, Holz FG, Schmitz-Valckenberg S, Wu Z, Guymer RH, Luu CD. Validation of an Automated Quantification of Relative Ellipsoid Zone Reflectivity on Spectral Domain-Optical Coherence Tomography Images. Transl Vis Sci Technol 2020; 9:17. [PMID: 33133775 PMCID: PMC7581490 DOI: 10.1167/tvst.9.11.17] [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: 07/02/2020] [Accepted: 09/24/2020] [Indexed: 11/24/2022] Open
Abstract
Purpose Relative ellipsoid zone reflectivity (rEZR) represents a potential biomarker of photoreceptor health on spectral-domain optical coherence tomography (SD-OCT). Because manual quantification of rEZR is laborious and lacks of spatial resolution, automated quantification of the rEZR would be beneficial. The purpose of this study was to evaluate the reliability and reproducibility of an automated rEZR quantification method. Methods The rEZR was acquired using a manual and an automated approach in eyes with age-related macular degeneration (AMD) and healthy controls. The rEZR obtained from both methods was compared and the agreement between the methods and their reproducibility assessed. Results Forty eyes of 40 participants with a mean (± standard deviation) age of 65.2 ± 7.8 years were included. Both the manual and automated method showed that control eyes exhibit a greater rEZR than AMD eyes (P < 0.001). Overall, the limits of agreement between the manual and automated method were -7.5 to 7.3 arbitrary units (AU) and 95% of the data points had a difference in the rEZR between the methods of ±8.2%. An expected perfect reproducibility was observed for the automated method, whereas the manual method had a coefficient of repeatability of 6.3 arbitrary units. Conclusions The automated quantification of rEZR method is reliable and reproducible. Further studies of the rEZR as a novel biomarker for AMD severity and progression are warranted. Translational Relevance Automated quantification of SD-OCT-based rEZR allows for its comprehensive and longitudinal characterization evaluating its relevance as an in vivo biomarker of photoreceptor function and its prognostic value for AMD progression.
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Affiliation(s)
- Sarah Thiele
- Department of Ophthalmology, University of Bonn, Bonn, Germany.,GRADE Reading Center, University of Bonn, Bonn, Germany
| | - Ben Isselmann
- Department of Ophthalmology, University of Bonn, Bonn, Germany
| | - Maximilian Pfau
- Department of Ophthalmology, University of Bonn, Bonn, Germany.,GRADE Reading Center, University of Bonn, Bonn, Germany.,Department of Biomedical Data Science, Stanford University, Stanford, California, USA
| | - Frank G Holz
- Department of Ophthalmology, University of Bonn, Bonn, Germany.,GRADE Reading Center, University of Bonn, Bonn, Germany
| | - Steffen Schmitz-Valckenberg
- Department of Ophthalmology, University of Bonn, Bonn, Germany.,GRADE Reading Center, University of Bonn, Bonn, Germany
| | - Zhichao Wu
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia.,Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Australia
| | - Robyn H Guymer
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia.,Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Australia
| | - Chi D Luu
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia.,Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Australia
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12
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Pollreisz A, Neschi M, Sloan KR, Pircher M, Mittermueller T, Dacey DM, Schmidt-Erfurth U, Curcio CA. Atlas of Human Retinal Pigment Epithelium Organelles Significant for Clinical Imaging. Invest Ophthalmol Vis Sci 2020; 61:13. [PMID: 32648890 PMCID: PMC7425708 DOI: 10.1167/iovs.61.8.13] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 04/27/2020] [Indexed: 02/07/2023] Open
Abstract
Purpose To quantify organelles impacting imaging in the cell body and intact apical processes of human retinal pigment epithelium (RPE), including melanosomes, lipofuscin-melanolipofuscin (LM), mitochondria, and nuclei. Methods A normal perifovea of a 21-year-old white male was preserved after rapid organ recovery. An aligned image stack was generated using serial block-face scanning electron microscopy and was annotated by expert readers (TrakEM, ImageJ). Acquired measures included cell body and nuclear volume (n = 17); organelle count in apical processes (n = 17) and cell bodies (n = 8); distance of cell body organelles along a normalized apical-basal axis (n = 8); and dimensions of organelle-bounding boxes in apical processes in selected subsamples of cell bodies and apical processes. Results In 2661 sections through 17 cells, apical processes contained 65 ± 24 melanosomes in mononucleate (n = 15) and 131 ± 28 in binucleate cells (n = 2). Cell bodies contained 681 ± 153 LM and 734 ± 170 mitochondria. LM was excluded from the basal quartile, and mitochondria from the apical quartile. Lengths of melanosomes, LM, and mitochondria, respectively were 2305 ± 528, 1320 ± 574, and 1195 ± 294 nm. The ratio of cell body to nucleus volume was 4.6 ± 0.4. LM and mitochondria covered 75% and 63%, respectively, of the retinal imaging plane. Conclusions Among RPE signal sources for optical coherence tomography, LM and mitochondria are the most numerous reflective cell body organelles. These and our published data show that most melanosomes are in apical processes. Overlapping LM and previously mitochondria cushions may support multiple reflective bands in cell bodies. This atlas of subcellular reflectivity sources can inform development of advanced optical coherence tomography technologies.
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Affiliation(s)
- Andreas Pollreisz
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - Martina Neschi
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - Kenneth R. Sloan
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Department of Computer Science, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Michael Pircher
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | | | - Dennis M. Dacey
- Department of Biologic Structure, University of Washington, Seattle, Washington, United States
| | | | - Christine A. Curcio
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
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13
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Sommer AP, Schemmer P, Pavláth AE, Försterling HD, Mester ÁR, Trelles MA. Quantum biology in low level light therapy: death of a dogma. ANNALS OF TRANSLATIONAL MEDICINE 2020; 8:440. [PMID: 32395484 PMCID: PMC7210155 DOI: 10.21037/atm.2020.03.159] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Background It is shown that despite exponential increase in the number of clinically exciting results in low level light therapy (LLLT), scientific progress in the field is retarded by a wrong fundamental model employed to explain the photon-cell interaction as well as by an inadequate terminology. This is reflected by a methodological stagnation in LLLT, persisting since 1985. The choice of the topics is, by necessity, somewhat arbitrary. Obviously, we are writing more about the fields we know more about. In some cases, there are obvious objective reasons for the choice. Progress in LLLT is currently realized by a trial and error process, as opposed to a systematic approach based on a valid photon-cell interaction model. Methods The strategy to overcome the current problem consists in a comprehensive analysis of the theoretical foundation of LLLT, and if necessary, by introducing new interaction models and checking their validity on the basis of the two pillars of scientific advance (I) agreement with experiment and (II) predictive capability. The list of references used in this work, does contain a representative part of what has been done in the photon-cell interaction theory in recent years, considered as ascertained by the scientific community. Results Despite the immense literature on the involvement of cytochrome c oxidase (COX) in LLLT, the assumption that COX is the main mitochondrial photoacceptor for R-NIR photons no longer can be counted as part of the theoretical framework proper, at least not after we have addressed the misleading points in the literature. Here, we report the discovery of a coupled system in mitochondria whose working principle corresponds to that of field-effect transistor (FET). The functional interplay of cytochrome c (emitter) and COX (drain) with a nanoscopic interfacial water layer (gate) between the two enzymes forms a biological FET in which the gate is controlled by R-NIR photons. By reducing the viscosity of the nanoscopic interfacial water layers within and around the mitochondrial rotary motor in oxidatively stressed cells R-NIR light promotes the synthesis of extra adenosine triphosphate (ATP). Conclusions Based on the results of our own work and a review of the published literature, we present the effect of R-NIR photons on nanoscopic interfacial water layers in mitochondria and cells as a novel understanding of the biomedical effects R-NIR light. The novel paradigm is in radical contrast to the theory that COX is the main absorber for R-NIR photons and responsible for the increase in ATP synthesis, a dogma propagated for more than 20 years.
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Affiliation(s)
| | - Peter Schemmer
- General, Visceral and Transplant Surgery, Medical University of Graz, Graz, Austria
| | - Attila E Pavláth
- Past President American Chemical Society, Western Regional Research Center, Albany, CA, USA
| | | | - Ádám R Mester
- National Laser Therapy Centre, Péterfy Sándor Teaching Hospital, Budapest, Hungary
| | - Mario A Trelles
- Plastic-Aesthetic Surgery, Vilafortuny Laser Centre, Jumeirah, Dubai, United Arab Emirates
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14
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Hughes JM, Clarke FM, Purslow PP, Warner RD. Meat color is determined not only by chromatic heme pigments but also by the physical structure and achromatic light scattering properties of the muscle. Compr Rev Food Sci Food Saf 2019; 19:44-63. [PMID: 33319522 DOI: 10.1111/1541-4337.12509] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 09/05/2019] [Accepted: 10/07/2019] [Indexed: 11/30/2022]
Abstract
Meat color is important for consumer acceptability, with excessively dark meat often associated with consumer rejection. It is determined chromatically by pigment content (measured by hue and chroma) and achromatically by scattering of light by the microstructure (measured by lightness), the latter of which has received minimal research focus. This review discusses the individual components of the meat microstructure that cause differences in achromatic contributions to color. Differences in achromatic light scattering between light and dark extremes of meat color are most likely explained by structural attributes within the muscle cell. These differences are proposed to arise from variations in (a) transverse shrinkage of the structural lattice of the myofilaments, myofibrils, and muscles fibers, (b) longitudinal shrinkage of the sarcomere, and (c) different protein composition of the surrounding medium (sarcoplasm and extracellular space). These are discussed at a mechanistic level, in relation to six parameters of the muscle cell: (a) protein surface charge altering the myofilament spacing, (b) protein solubility, (c) sarcoplasmic protein binding to myofilaments and myofibrils, (d) integrity of the cytoskeleton and cell adhesion proteins, (e) sarcomere integrity and myofibrillar proteins, and (f) myosin denaturation and rigor bond modification. New data are presented to support the proposed role of structural elements in muscle causing achromatic light scattering and their contribution to the surface color of meat. In addition, the relationships between lightness and water holding capacity and pH are explored and the economic impact of dark meat for the meat industry is discussed.
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Affiliation(s)
- Joanne M Hughes
- Agriculture and Food, CSIRO, Coopers Plains, Brisbane, QLD, 4108, Australia
| | - Frank M Clarke
- School of Environment and Science, Griffith University, Nathan, QLD, 4111, Australia
| | - Peter P Purslow
- Faculty of Veterinary Sciences, Food Science and Technology Department, National University of the Center of Buenos Aires Province, Tandil, B7000, Argentina
| | - Robyn D Warner
- School of Agriculture and Food, The University of Melbourne, Parkville, VIC, 3010, Australia
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15
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Zhang XU, van der Zee P, Atzeni I, Faber DJ, van Leeuwen TG, Sterenborg HJCM. Multidiameter single-fiber reflectance spectroscopy of heavily pigmented skin: modeling the inhomogeneous distribution of melanin. JOURNAL OF BIOMEDICAL OPTICS 2019; 24:1-11. [PMID: 31820596 PMCID: PMC7006040 DOI: 10.1117/1.jbo.24.12.127001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 10/28/2019] [Indexed: 05/05/2023]
Abstract
When analyzing multidiameter single-fiber reflectance (MDSFR) spectra, the inhomogeneous distribution of melanin pigments in skin tissue is usually not accounted for. Especially in heavily pigmented skins, this can result in bad fits and biased estimation of tissue optical properties. A model is introduced to account for the inhomogeneous distribution of melanin pigments in skin tissue. In vivo visible MDSFR measurements were performed on heavily pigmented skin of type IV to VI. Skin tissue optical properties and related physiological properties were extracted from the measured spectra using the introduced model. The absorption of melanin pigments described by the introduced model demonstrates a good correlation with the co-localized measurement of the well-known melanin index.
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Affiliation(s)
- Xu U. Zhang
- Amsterdam UMC, University of Amsterdam, Department of Biomedical Engineering and Physics, Amsterdam, The Netherlands
- Amsterdam UMC, Cancer Center Amsterdam, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
- Address all correspondence to Xu U. Zhang, E-mail:
| | | | - Isabella Atzeni
- University of Groningen, University Medical Center Groningen, Division of Vascular Medicine, Department of Internal Medicine, Groningen, The Netherlands
| | - Dirk J. Faber
- Amsterdam UMC, University of Amsterdam, Department of Biomedical Engineering and Physics, Amsterdam, The Netherlands
- Amsterdam UMC, Cancer Center Amsterdam, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Ton G. van Leeuwen
- Amsterdam UMC, University of Amsterdam, Department of Biomedical Engineering and Physics, Amsterdam, The Netherlands
- Amsterdam UMC, Cancer Center Amsterdam, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Henricus J. C. M. Sterenborg
- Amsterdam UMC, University of Amsterdam, Department of Biomedical Engineering and Physics, Amsterdam, The Netherlands
- Amsterdam UMC, Cancer Center Amsterdam, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
- The Netherlands Cancer Institute, Department of Surgery, Amsterdam, The Netherlands
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16
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Mohajerani H, Salehi AM, Tabeie F, Shafiei S, Tabrizi R. Can Low-Level Laser and Light-Emitting Diode Enhance the Stability of Dental Implants? J Maxillofac Oral Surg 2019; 19:302-306. [PMID: 32346244 DOI: 10.1007/s12663-019-01210-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Accepted: 03/13/2019] [Indexed: 11/29/2022] Open
Abstract
Purpose Stability of dental implants is an important factor for evaluation of osseointegration. The aim of this study was to evaluate the effect of combined use of low-level laser (LLL) and light-emitting diode (LED) therapy on the stability of dental implants during the healing phase. Materials and Methods This was a randomized clinical trial. Patients were assigned to two groups: In group 1, patients received LLL and LED 20 min/day for 10 days after implant insertion. Patients in group 2 (controls) did not undergo LLL and LED. The implant stability quotient (ISQ) was measured at 0 (time 0), 10 (time 1), 21 (time 2), 42 (time 3) and 63 days (time 4) after implant placement. Independent t test was used to compare the ISQs between the two groups. Results Fifty-eight patients were studied in two groups (n = 28). The mean ISQ did not differ immediately after insertion (P > 0.05). The mean ISQ differed significantly between the two groups on days 10, 21, 42 and 63 (P < 0.05). Results demonstrated an increase in the amount of ISQ in group 1 (intervention) at times 1, 2, 3 and 4. In the control group, the amount of ISQ decreased on days 10 and 21 following implant insertion, but increased afterward on days 42 and 63. Conclusion The results of this study showed that simultaneous use of LLL and LED increased the stability of the implants after 9 weeks of follow-up.
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Affiliation(s)
- Hassan Mohajerani
- 1OMFS Department, Shahid Beheshti Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Faraj Tabeie
- 3Department of Basic Sciences, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shervin Shafiei
- 1OMFS Department, Shahid Beheshti Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Reza Tabrizi
- 1OMFS Department, Shahid Beheshti Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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17
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Sommer AP. Mitochondrial cytochrome c oxidase is not the primary acceptor for near infrared light-it is mitochondrial bound water: the principles of low-level light therapy. ANNALS OF TRANSLATIONAL MEDICINE 2019; 7:S13. [PMID: 31032294 DOI: 10.21037/atm.2019.01.43] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Sawyer TW, Chandra S, Rice PFS, Koevary JW, Barton JK. Three-dimensional texture analysis of optical coherence tomography images of ovarian tissue. Phys Med Biol 2018; 63:235020. [PMID: 30511664 PMCID: PMC6934175 DOI: 10.1088/1361-6560/aaefd2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Ovarian cancer has the lowest survival rate among all gynecologic cancers due to predominantly late diagnosis. Optical coherence tomography (OCT) has been applied successfully to experimentally image the ovaries in vivo; however, a robust method for analysis is still required to provide quantitative diagnostic information. Recently, texture analysis has proved to be a useful tool for tissue characterization; unfortunately, existing work in the scope of OCT ovarian imaging is limited to only analyzing 2D sub-regions of the image data, discarding information encoded in the full image area, as well as in the depth dimension. Here we address these challenges by testing three implementations of texture analysis for the ability to classify tissue type. First, we test the traditional case of extracted 2D regions of interest; then we extend this to include the entire image area by segmenting the organ from the background. Finally, we conduct a full volumetric analysis of the image volume using 3D segmented data. For each case, we compute features based on the Grey-Level Co-occurence Matrix and also by introducing a new approach that evaluates the frequency distribution in the image by computing the energy density. We test these methods on a mouse model of ovarian cancer to differentiate between age, genotype, and treatment. The results show that the 3D application of texture analysis is most effective for differentiating tissue types, yielding an average classification accuracy of 78.6%. This is followed by the analysis in 2D with the segmented image volume, yielding an average accuracy of 71.5%. Both of these improve on the traditional approach of extracting square regions of interest, which yield an average classification accuracy of 67.7%. Thus, applying texture analysis in 3D with a fully segmented image volume is the most robust approach to quantitatively characterizing ovarian tissue.
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Affiliation(s)
- Travis W Sawyer
- College of Optical Sciences, The University of Arizona, Tucson 85721, AZ, United States of America
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Design Considerations for Murine Retinal Imaging Using Scattering Angle Resolved Optical Coherence Tomography. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8112159] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Optical coherence tomography (OCT), an optical imaging approach enabling cross-sectional analysis of turbid samples, is routinely used for retinal imaging in human and animal models of diseases affecting the retina. Scattering angle resolved (SAR-)OCT has previously been demonstrated as offering additional contrast in human studies, but no SAR-OCT system has been reported in detail for imaging the retinas of mice. An optical model of a mouse eye was designed and extended for validity at wavelengths of light around 1310 nm; this model was then utilized to develop a SAR-OCT design for murine retinal imaging. A Monte Carlo technique simulates light scattering from the retina, and the simulation results are confirmed with SAR-OCT images. Various images from the SAR-OCT system are presented and utility of the system is described. SAR-OCT is demonstrated as a viable and robust imaging platform to extend utility of retinal OCT imaging by incorporating scattering data into investigative ophthalmologic analysis.
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Ono Y, Esaki K, Takahashi Y, Nakabayashi M, Ichinose M, Lee K. Muscular blood flow responses as an early predictor of the severity of diabetic neuropathy at a later stage in streptozotocin-induced type I diabetic rats: a diffuse correlation spectroscopy study. BIOMEDICAL OPTICS EXPRESS 2018; 9:4539-4551. [PMID: 30615744 PMCID: PMC6157794 DOI: 10.1364/boe.9.004539] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 08/10/2018] [Accepted: 08/16/2018] [Indexed: 06/09/2023]
Abstract
We propose a novel application of diffuse correlation spectroscopy to evaluate microvascular malfunctions of muscle tissue affected by hyperglycemia and determine their correlation with the severity of diabetic neuropathy at a later stage. Microvascular responses of the thigh muscle and the mechanical pain threshold of the hind paw of streptozotocin-induced type I diabetic rats were continuously monitored once per week for 70 days. Significantly decreased baseline blood flow and reactive hyperemia responses were observed as early as 1 week after hyperglycemia induction. The reactive hyperemia response at 2 weeks of hyperglycemia was highly correlated with the mechanical pain threshold at 8 weeks, at which time a decreased pain threshold was statistically confirmed in hyperglycemic rats relative to controls.
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Affiliation(s)
- Yumie Ono
- Department of Electronics and Bioinformatics, School of Science and Technology, Meiji University, 1-1-1 Higashi-Mita, Tama-ku, Kawasaki, Kanagawa 2148571, Japan
| | - Kimiya Esaki
- Electrical Engineering Program, Graduate School of Science and Technology, Meiji University, 1-1-1 Higashi-Mita, Tama-ku, Kawasaki, Kanagawa 2148571, Japan
| | - Yuta Takahashi
- Electrical Engineering Program, Graduate School of Science and Technology, Meiji University, 1-1-1 Higashi-Mita, Tama-ku, Kawasaki, Kanagawa 2148571, Japan
| | - Mikie Nakabayashi
- Department of Electronics and Bioinformatics, School of Science and Technology, Meiji University, 1-1-1 Higashi-Mita, Tama-ku, Kawasaki, Kanagawa 2148571, Japan
- Electrical Engineering Program, Graduate School of Science and Technology, Meiji University, 1-1-1 Higashi-Mita, Tama-ku, Kawasaki, Kanagawa 2148571, Japan
| | - Masashi Ichinose
- Human Integrative Physiology Laboratory, School of Business Administration, Meiji University, 1-1 Surugadai, Kanda, Chiyoda-ku, Tokyo 1018301, Japan
| | - Kijoon Lee
- College of Transdisciplinary Studies, Daegu Gyeongbuk Institute of Science and Technology, 333 Techno Jungang-daero, Hyeonpung-myeon, Dalseong-gun, Daegu, South Korea
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OPTICAL COHERENCE TOMOGRAPHY AND HISTOLOGY OF AGE-RELATED MACULAR DEGENERATION SUPPORT MITOCHONDRIA AS REFLECTIVITY SOURCES. Retina 2018; 38:445-461. [PMID: 29210936 DOI: 10.1097/iae.0000000000001946] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
PURPOSE Widespread adoption of optical coherence tomography has revolutionized the diagnosis and management of retinal disease. If the cellular and subcellular sources of reflectivity in optical coherence tomography can be identified, the value of this technology will be advanced even further toward precision medicine, mechanistic thinking, and molecular discovery. Four hyperreflective outer retinal bands are created by the exquisite arrangement of photoreceptors, Müller cells, retinal pigment epithelium, and Bruch membrane. Because of massed effects of these axially compartmentalized and transversely aligned cells, reflectivity can be localized to the subcellular level. This review focuses on the second of the four bands, called ellipsoid zone in a consensus clinical lexicon, with the central thesis that mitochondria in photoreceptor inner segments are a major independent reflectivity source in this band, because of Mie scattering and waveguiding. METHODS We review the evolution of Band 2 nomenclature in published literature and discuss the origins of imaging signals from photoreceptor mitochondria that could make these organelles visible in vivo. RESULTS Our recent data pertain to outer retinal tubulation, a unique neurodegenerative and gliotic structure with a highly reflective border, prominent in late age-related macular degeneration. High-resolution histology and multimodal imaging of outer retinal tubulation together provide evidence that inner segment mitochondria undergoing fission and translocation toward the nucleus provide the reflectivity signal. CONCLUSION Our data support adoption of the ellipsoid zone nomenclature. Identifying subcellular signal sources will newly inform clinical.
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The Comparison of the Efficacy of Blue Light-Emitting Diode Light and 980-nm Low-Level Laser Light on Bone Regeneration. J Craniofac Surg 2016; 27:2185-2189. [DOI: 10.1097/scs.0000000000003068] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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Wu JS, Yu LP, Chou C. Measurement of the surface effect of a small scattering object in a highly scattering medium by use of diffuse photon-pairs density wave. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:60504. [PMID: 27304418 DOI: 10.1117/1.jbo.21.6.060504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Accepted: 05/27/2016] [Indexed: 06/06/2023]
Abstract
The surface effect close to the boundary of a small light-scattering object in a highly scattering medium is experimentally demonstrated. This is the first attempt to measure the surface effect of a small spherical scattering object in 1% intralipid solution by use of developed diffuse photon-pairs density wave (DPPDW) in terms of the amplitude and phase detection. Theoretically, the surface effect of a small scattering object in turbid media is localized close to the boundary according to the perturbation theory, concerning an inhomogeneous distribution of the diffusion coefficient in the frequency-domain diffusion equation. Hence, an improvement of the spatial resolution of the image via an inverse algorithm, which relates to detection sensitivity of localization to the boundary of the image object in a multiple scattering medium, is anticipated. In this study, we demonstrate that DPPDW is able to sense the surface effect of a 2-mm spherical scattering object in 1% intralipid solution, with high sensitivity. Subsequently, an improvement of spatial resolution of imaging in turbid media by using DPPDW in comparison with conventional diffuse photon density wave (DPDW) using inverse algorithm is discussed.
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Affiliation(s)
- Jheng-Syong Wu
- Chang Gung University, Graduate Institute of Electro-Optical Engineering, No. 259, Wenhua 1st Road, Kwei-shan District, Taoyuan 333, TaiwanbInstitute of Chemistry, Academic Sinica, No. 128, Section 2, Academia Road, Nankang District, Taipei 115, Taiwan
| | - Li-Ping Yu
- Chang Gung University, Graduate Institute of Electro-Optical Engineering, No. 259, Wenhua 1st Road, Kwei-shan District, Taoyuan 333, Taiwan
| | - Chien Chou
- Chang Gung University, Graduate Institute of Electro-Optical Engineering, No. 259, Wenhua 1st Road, Kwei-shan District, Taoyuan 333, Taiwan
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Diffuse optical spectroscopic imaging of subcutaneous adipose tissue metabolic changes during weight loss. Int J Obes (Lond) 2016; 40:1292-300. [PMID: 27089996 PMCID: PMC4970874 DOI: 10.1038/ijo.2016.43] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 01/26/2016] [Accepted: 03/04/2016] [Indexed: 02/06/2023]
Abstract
Background Changes in subcutaneous adipose tissue (AT) structure and metabolism have been shown to correlate with the development of obesity and related metabolic disorders. Measurements of AT physiology could provide new insight into metabolic disease progression and response to therapy. An emerging functional imaging technology, Diffuse Optical Spectroscopic Imaging (DOSI), was used to obtain quantitative measures of near infrared (NIR) AT optical and physiological properties. Methods 10 overweight or obese adults were assessed during three-months on calorie-restricted diets. DOSI-derived tissue concentrations of hemoglobin, water, and lipid and the wavelength-dependent scattering amplitude (A) and slope (b) obtained from 30 abdominal locations and three time points (T0, T6, T12) were calculated and analyzed using linear mixed effects models, and were also used to form 3D surface images. Results Subjects lost a mean of 11.7 ± 3.4% of starting weight, while significant changes in A (+0.23 ± 0.04 mm−1, adj. p < 0.001), b (−0.17 ± 0.04, adj. p < 0.001), tissue water fraction (+7.2 ± 1.1%, adj. p < 0.001) and deoxyhemoglobin [HbR] (1.1 ± 0.3 µM, adj. p < 0.001) were observed using mixed effect model analysis. Discussion Optical scattering signals reveal alterations in tissue structure which possibly correlate with reductions in adipose cell volume, while water and hemoglobin dynamics suggest improved AT perfusion and oxygen extraction. These results suggest that DOSI measurements of NIR optical and physiological properties could be used to enhance understanding of the role of AT in metabolic disorders and provide new strategies for diagnostic monitoring of obesity and weight loss.
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Halaney DL, Zahedivash A, Phipps JE, Wang T, Dwelle J, Saux CJL, Asmis R, Milner TE, Feldman MD. Differences in forward angular light scattering distributions between M1 and M2 macrophages. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:115002. [PMID: 26538329 PMCID: PMC4881287 DOI: 10.1117/1.jbo.20.11.115002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 10/09/2015] [Indexed: 05/11/2023]
Abstract
The ability to distinguish macrophage subtypes noninvasively could have diagnostic potential in cancer, atherosclerosis, and diabetes, where polarized M1 and M2 macrophages play critical and often opposing roles. Current methods to distinguish macrophage subtypes rely on tissue biopsy. Optical imaging techniques based on light scattering are of interest as they can be translated into biopsy-free strategies. Because mitochondria are relatively strong subcellular light scattering centers, and M2 macrophages are known to have enhanced mitochondrial biogenesis compared to M1, we hypothesized that M1 and M2 macrophages may have different angular light scattering profiles. To test this, we developed an in vitro angle-resolved forward light scattering measurement system. We found that M1 and M2 macrophage monolayers scatter relatively unequal amounts of light in the forward direction between 1.6 deg and 3.2 deg with M2 forward scattering significantly more light than M1 at increasing angles. The ratio of forward scattering can be used to identify the polarization state of macrophage populations in culture.
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Affiliation(s)
- David L. Halaney
- University of Texas Health Science Center at San Antonio, Division of Cardiology, Department of Medicine, 7703 Floyd Curl Drive, San Antonio, Texas 78229, United States
- South Texas Veterans Health Care System, Department of Veterans Affairs, 7400 Merton Minter, San Antonio, Texas 78229, United States
| | - Aydin Zahedivash
- University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712, United States
| | - Jennifer E. Phipps
- University of Texas Health Science Center at San Antonio, Division of Cardiology, Department of Medicine, 7703 Floyd Curl Drive, San Antonio, Texas 78229, United States
| | - Tianyi Wang
- University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712, United States
| | - Jordan Dwelle
- South Texas Veterans Health Care System, Department of Veterans Affairs, 7400 Merton Minter, San Antonio, Texas 78229, United States
- University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712, United States
| | - Claude Jourdan Le Saux
- University of Texas Health Science Center at San Antonio, Division of Cardiology, Department of Medicine, 7703 Floyd Curl Drive, San Antonio, Texas 78229, United States
| | - Reto Asmis
- University of Texas Health Science Center at San Antonio, Departments of Clinical Laboratory Sciences and Biochemistry, 7703 Floyd Curl Drive, San Antonio, Texas 78229, United States
| | - Thomas E. Milner
- University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712, United States
| | - Marc D. Feldman
- University of Texas Health Science Center at San Antonio, Division of Cardiology, Department of Medicine, 7703 Floyd Curl Drive, San Antonio, Texas 78229, United States
- South Texas Veterans Health Care System, Department of Veterans Affairs, 7400 Merton Minter, San Antonio, Texas 78229, United States
- Address all correspondence to: Marc D. Feldman, E-mail:
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Ahmad I, Rehman A, Khan JA, Rafi M, Khurshid A, Nisar H, Zaidi S, Ikram M. Effects of varying local temperature on the optical properties of cells in-vitro. Photodiagnosis Photodyn Ther 2015; 12:459-65. [DOI: 10.1016/j.pdpdt.2015.05.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 04/13/2015] [Accepted: 05/05/2015] [Indexed: 12/26/2022]
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Zhai X, Gong Y, Yang W, Kang H, Zhang X. Mn-doped CdS/ZnS/CdS QD-based fluorescent nanosensor for rapid, selective, and ultrasensitive detection of copper(ii) ion. RSC Adv 2015. [DOI: 10.1039/c5ra11435g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Energy levels of Mn-doped QD-based nanosensor and the quenching mechanism of the nanosensor by Cu2+.
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Affiliation(s)
- Xiaoman Zhai
- Key Laboratory of Cluster Science of Ministry of Education
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials
- School of Chemistry
- Beijing Institute of Technology
- Beijing 100081
| | - Yunqian Gong
- Key Laboratory of Cluster Science of Ministry of Education
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials
- School of Chemistry
- Beijing Institute of Technology
- Beijing 100081
| | - Wen Yang
- Key Laboratory of Cluster Science of Ministry of Education
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials
- School of Chemistry
- Beijing Institute of Technology
- Beijing 100081
| | - Huaizhi Kang
- College of Chemistry and Chemical Engineering
- Xiamen University
- Xiamen
- P. R. China
| | - Xiaoling Zhang
- Key Laboratory of Cluster Science of Ministry of Education
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials
- School of Chemistry
- Beijing Institute of Technology
- Beijing 100081
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Pellicioli ACA, Martins MD, Dillenburg CS, Marques MM, Squarize CH, Castilho RM. Laser phototherapy accelerates oral keratinocyte migration through the modulation of the mammalian target of rapamycin signaling pathway. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:028002. [PMID: 24531144 DOI: 10.1117/1.jbo.19.2.028002] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 01/17/2014] [Indexed: 06/03/2023]
Abstract
Keratinocytes play a central role in wound healing by responding to tissue injury through the activation of cellular proliferation and migration. Current clinical evidence suggests that the laser phototherapy (LPT) accelerates wound healing in a variety of oral diseases; however, the molecular mechanisms involved in response to LPT are not fully understood. Oral keratinocytes (NOK-SI) maintained under nutritional-deficit culture medium (2% fetal bovine serum) were irradiated with InGaAlP laser (660 nm; 40 mW; 0.04 cm2 spot size) in punctual and contact modes. The energy densities used were 4 and 20 J/cm2 corresponding to 4 and 20 s of exposure times and 0.16 and 0.8 J of energy per point, respectively. Three sessions of irradiations were applied with 6-h intervals. Further, the impact of LPT over cellular migration, proliferation, and activation of the mammalian target of rapamycin (mTOR) pathway, known to play a major role in epithelial migration and wound healing, was analyzed. Compared with control cells, the LPT-treated cells showed accelerated cellular migration without any changes in proliferation. Furthermore, LPT resulted in an increase in the phospho-S6 ribosomal protein, indicating activation of the mTOR signaling pathway. Collectively, these findings suggest that the LPT activates mTOR signaling pathway, promotes epithelial cell migration, and accelerates healing of oral mucosa.
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Affiliation(s)
- Ana Carolina Amorim Pellicioli
- Universidade Federal do Rio Grande do Sul, School of Dentistry, Department of Oral Pathology, Porto Alegre, Rio Grande do Sul 90035-003, Brazil
| | - Manoela Domingues Martins
- Universidade Federal do Rio Grande do Sul, School of Dentistry, Department of Oral Pathology, Porto Alegre, Rio Grande do Sul 90035-003, Brazil
| | - Caroline Siviero Dillenburg
- Universidade Federal do Rio Grande do Sul, School of Dentistry, Department of Oral Pathology, Porto Alegre, Rio Grande do Sul 90035-003, Brazil
| | - Márcia Martins Marques
- University of São Paulo, School of Dentistry, Department of Dentistry, São Paulo, São Paulo 05508-000, Brazil
| | - Cristiane H Squarize
- University of Michigan, School of Dentistry, Laboratory of Epithelial Biology, Department of Periodontics and Oral Medicine, Ann Arbor, Michigan 48109-1078
| | - Rogerio M Castilho
- University of Michigan, School of Dentistry, Laboratory of Epithelial Biology, Department of Periodontics and Oral Medicine, Ann Arbor, Michigan 48109-1078
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Fu Y, Ding C, Zhu A, Deng Z, Tian Y, Jin M. Two-photon ratiometric fluorescent sensor based on specific biomolecular recognition for selective and sensitive detection of copper ions in live cells. Anal Chem 2013; 85:11936-43. [PMID: 24256150 DOI: 10.1021/ac403527c] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In this work, we develop a ratiometric two-photon fluorescent probe, ATD@QD-E2Zn2SOD (ATD = amino triphenylamine dendron, QD = CdSe/ZnSe quantum dot, E2Zn2SOD = Cu-free derivative of bovine liver copper-zinc superoxide dismutase), for imaging and sensing the changes of intracellular Cu(2+) level with clear red-to-yellow color change based on specific biomolecular recognition of E2Zn2SOD for Cu(2+) ion. The inorganic-organic nanohybrided fluorescent probe features two independent emission peaks located at 515 nm for ATD and 650 nm for QDs, respectively, under two-photon excitation at 800 nm. Upon addition of Cu(2+) ions, the red fluorescence of QDs drastically quenches, while the green emission from ATD stays constant and serves as a reference signal, thus resulting in the ratiometric detection of Cu(2+) with high accuracy by two-photon microscopy (TPM). The present probe shows high sensivity, broad linear range (10(-7)-10(-3) M), low detection limit down to ∼10 nM, and excellent selectivity over other metal ions, amino acids, and other biological species. Meanwhile, a QD-based inorganic-organic probe demonstrates long-term photostability, good cell-permeability, and low cytotoxicity. As a result, the present probe can visualize Cu(2+) changes in live cells by TPM. To the best of our knowledge, this is the first report for the development of a QD-based two-photon ratiometric fluorescence probe suitable for detection of Cu(2+) in live cells.
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Affiliation(s)
- Yan Fu
- Department of Chemistry, Tongji University , Siping Road 1239, Shanghai 200092, P. R. China
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Hart VP, Doyle TE. Simulation of diffuse photon migration in tissue by a Monte Carlo method derived from the optical scattering of spheroids. APPLIED OPTICS 2013; 52:6220-6229. [PMID: 24085080 DOI: 10.1364/ao.52.006220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 07/29/2013] [Indexed: 06/02/2023]
Abstract
A Monte Carlo method was derived from the optical scattering properties of spheroidal particles and used for modeling diffuse photon migration in biological tissue. The spheroidal scattering solution used a separation of variables approach and numerical calculation of the light intensity as a function of the scattering angle. A Monte Carlo algorithm was then developed which utilized the scattering solution to determine successive photon trajectories in a three-dimensional simulation of optical diffusion and resultant scattering intensities in virtual tissue. Monte Carlo simulations using isotropic randomization, Henyey-Greenstein phase functions, and spherical Mie scattering were additionally developed and used for comparison to the spheroidal method. Intensity profiles extracted from diffusion simulations showed that the four models differed significantly. The depth of scattering extinction varied widely among the four models, with the isotropic, spherical, spheroidal, and phase function models displaying total extinction at depths of 3.62, 2.83, 3.28, and 1.95 cm, respectively. The results suggest that advanced scattering simulations could be used as a diagnostic tool by distinguishing specific cellular structures in the diffused signal. For example, simulations could be used to detect large concentrations of deformed cell nuclei indicative of early stage cancer. The presented technique is proposed to be a more physical description of photon migration than existing phase function methods. This is attributed to the spheroidal structure of highly scattering mitochondria and elongation of the cell nucleus, which occurs in the initial phases of certain cancers. The potential applications of the model and its importance to diffusive imaging techniques are discussed.
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Noninvasive diffusive optical imaging of the auditory response to birdsong in the zebra finch. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2013; 199:227-38. [PMID: 23322445 DOI: 10.1007/s00359-012-0788-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 12/08/2012] [Accepted: 12/17/2012] [Indexed: 01/15/2023]
Abstract
Songbirds communicate by learned vocalizations with concomitant changes in neurophysiological and genomic activities in discrete parts of the brain. Here, we tested a novel implementation of diffusive optical imaging (also known as diffuse optical imaging, DOI) for monitoring brain physiology associated with vocal signal perception. DOI noninvasively measures brain activity using red and near-infrared light delivered through optic fibers (optodes) resting on the scalp. DOI does not harm subjects, so it raises the possibility of repeatedly measuring brain activity and the effects of accumulated experience in the same subject over an entire life span, all while leaving tissue intact for further study. We developed a custom-made apparatus for interfacing optodes to the zebra finch (Taeniopygia guttata) head using 3D modeling software and rapid prototyping technology, and applied it to record responses to presentations of birdsong in isoflurane-anesthetized zebra finches. We discovered a subtle but significant difference between the hemoglobin spectra of zebra finches and mammals which has a major impact in how hemodynamic responses are interpreted in the zebra finch. Our measured responses to birdsong playback were robust, highly repeatable, and readily observed in single trials. Responses were complex in shape and closely paralleled responses described in mammals. They were localized to the caudal medial portion of the brain, consistent with response localization from prior gene expression, electrophysiological, and functional magnetic resonance imaging studies. These results define an approach for collecting neurophysiological data from songbirds that should be applicable to diverse species and adaptable for studies in awake behaving animals.
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Chang PC, Chien LY, Ye Y, Kao MJ. Irradiation by light-emitting diode light as an adjunct to facilitate healing of experimental periodontitis in vivo. J Periodontal Res 2012; 48:135-43. [PMID: 22845797 DOI: 10.1111/j.1600-0765.2012.01511.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND OBJECTIVE This study evaluated the biostimulatory effect of 660 nm light-emitting diode (LED) as an adjunct in the treatment of experimental periodontitis. MATERIAL AND METHODS Ninety-six Sprague-Dawley rats underwent experimental periodontitis by placement of a silk ligature followed with or without additive Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) injection. Irradiation with LED light was performed at varying energy densities of 5, 10 and 15 J/cm2, 1 d after debridement and detoxification. Rats were killed at 3, 7 and 14 d after irradiation with LED light, and the effect of irradiation was evaluated by descriptive histology and quantitative measurements of periodontal bone loss, inflammatory infiltration and cellular proliferation. RESULTS Reduction of inflammation, accelerated collagen deposition and realignment was noted following irradiation with LED light at densities of 10 and 15 J/cm2, and temporary reduction of periodontal bone loss, as well as bundle bone apposition, was noted at day 3 in rats treated with 10 J/cm2 light. The biomodulatory effect was stronger in sites treated with Pg-LPS injection. In sites without Pg-LPS injection, temporary reduction of inflammation was noted in all LED light-irradiated specimens at day 3. No significant change in cellular proliferation was noted in any LED light-treated group. CONCLUSIONS LED light (660 nm) with an energy density of 10 J/cm2 appeared suitable as an adjunct modality for periodontitis by temporarily reducing inflammation, facilitating collagen realignment and bundle bone deposition. Future studies will aim to amplify the biostimulatory effect of LED light by adding a supplementary medium or repeated irradiation.
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Affiliation(s)
- P-C Chang
- Faculty of Dentistry, National University of Singapore, Singapore, Singapore.
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Yao J, Wang LV. Photoacoustic tomography: fundamentals, advances and prospects. CONTRAST MEDIA & MOLECULAR IMAGING 2011; 6:332-45. [PMID: 22025335 PMCID: PMC3205414 DOI: 10.1002/cmmi.443] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Optical microscopy has been contributing to the development of life science for more than three centuries. However, due to strong optical scattering in tissue, its in vivo imaging ability has been restricted to studies at superficial depths. Advances in photoacoustic tomography (PAT) now allow multiscale imaging at depths from sub-millimeter to several centimeters, with spatial resolutions from sub-micrometer to sub-millimeter. Because of this high scalability and its unique optical absorption contrast, PAT is capable of performing anatomical, functional, molecular and fluid-dynamic imaging at various system levels, and is playing an increasingly important role in fundamental biological research and clinical practice. This review discusses recent technical progress in PAT and presents corresponding applications. It ends with a discussion of several prospects and their technical challenges.
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Affiliation(s)
- Junjie Yao
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, Campus Box 1097, One Brookings Drive, St. Louis, MO 63130-4899
| | - Lihong V. Wang
- Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, Campus Box 1097, One Brookings Drive, St. Louis, MO 63130-4899
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Pasternack RM, Zheng JY, Boustany NN. Detection of mitochondrial fission with orientation-dependent optical Fourier filters. Cytometry A 2011; 79:137-48. [PMID: 21265007 DOI: 10.1002/cyto.a.21011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2010] [Revised: 10/25/2010] [Accepted: 11/22/2010] [Indexed: 11/08/2022]
Abstract
We utilize a recently developed optical imaging method based on Fourier processing with Gabor-like filters to detect changes in light scattering resulting from alterations in mitochondrial structure in endothelial cells undergoing apoptosis. Imaging based on Gabor filters shows a significant decrease in the orientation of subcellular organelles at 60 to 100 minutes following apoptosis induction and concomitant with mitochondrial fragmentation observed by fluorescence. The optical scatter changes can be detected at low resolution at the whole cell level. At high resolution, we combine fluorescence imaging of the mitochondria with optical Fourier-based imaging to demonstrate that the dynamic decrease in organelle orientation measured by optical Gabor filtering is spatially associated with fluorescent mitochondria and remains largely absent from nonfluorescent subcellular regions. These results provide strong evidence that the optical Gabor responses track mitochondrial fission during apoptosis and can be used to provide label-free, rapid monitoring of this morphological process within single cells.
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Affiliation(s)
- Robert M Pasternack
- Department of Biomedical Engineering, Rutgers University, Piscataway, NJ 08854, USA
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McLaughlin BL, Wells AC, Virtue S, Vidal-Puig A, Wilkinson TD, Watson CJE, Robertson PA. Electrical and optical spectroscopy for quantitative screening of hepatic steatosis in donor livers. Phys Med Biol 2010; 55:6867-79. [PMID: 21048293 DOI: 10.1088/0031-9155/55/22/017] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Macro-steatosis in deceased donor livers is increasingly prevalent and is associated with poor or non-function of the liver upon reperfusion. Current assessment of the extent of steatosis depends upon the macroscopic assessment of the liver by the surgeon and histological examination, if available. In this paper we demonstrate electrical and optical spectroscopy techniques which quantitatively characterize fatty infiltration in liver tissue. Optical spectroscopy showed a correlation coefficient of 0.85 in humans when referenced to clinical hematoxylin and eosin (H&E) sections in 20 human samples. With further development, an optical probe may provide a comprehensive measure of steatosis across the liver at the time of procurement.
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Affiliation(s)
- B L McLaughlin
- Engineering Department, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 OFA, UK.
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Gratton G, Fabiani M. Fast optical imaging of human brain function. Front Hum Neurosci 2010; 4:52. [PMID: 20631845 PMCID: PMC2903192 DOI: 10.3389/fnhum.2010.00052] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Accepted: 06/02/2010] [Indexed: 11/29/2022] Open
Abstract
Great advancements in brain imaging during the last few decades have opened a large number of new possibilities for neuroscientists. The most dominant methodologies (electrophysiological and magnetic resonance-based methods) emphasize temporal and spatial information, respectively. However, theorizing about brain function has recently emphasized the importance of rapid (within 100 ms or so) interactions between different elements of complex neuronal networks. Fast optical imaging, and in particular the event-related optical signal (EROS, a technology that has emerged over the last 15 years) may provide descriptions of localized (to sub-cm level) brain activity with a temporal resolution of less than 100 ms. The main limitations of EROS are its limited penetration, which allows us to image cortical structures not deeper than 3 cm from the surface of the head, and its low signal-to-noise ratio. Advantages include the fact that EROS is compatible with most other imaging methods, including electrophysiological, magnetic resonance, and trans-cranial magnetic stimulation techniques, with which can be recorded concurrently. In this paper we present a summary of the research that has been conducted so far on fast optical imaging, including evidence for the possibility of recording neuronal signals with this method, the properties of the signals, and various examples of applications to the study of human cognitive neuroscience. Extant issues, controversies, and possible future developments are also discussed.
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Affiliation(s)
- Gabriele Gratton
- Department of Psychology, University of Illinois at Urbana-ChampaignUrbana, IL, USA
- Beckman Institute, University of Illinois at Urbana-ChampaignUrbana, IL, USA
| | - Monica Fabiani
- Department of Psychology, University of Illinois at Urbana-ChampaignUrbana, IL, USA
- Beckman Institute, University of Illinois at Urbana-ChampaignUrbana, IL, USA
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Apoptosis- and necrosis-induced changes in light attenuation measured by optical coherence tomography. Lasers Med Sci 2010; 25:259-67. [PMID: 19756838 PMCID: PMC2807596 DOI: 10.1007/s10103-009-0723-y] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2008] [Accepted: 07/31/2009] [Indexed: 11/15/2022]
Abstract
Optical coherence tomography (OCT) was used to determine optical properties of pelleted human fibroblasts in which necrosis or apoptosis had been induced. We analysed the OCT data, including both the scattering properties of the medium and the axial point spread function of the OCT system. The optical attenuation coefficient in necrotic cells decreased from 2.2 ± 0.3 mm−1 to 1.3 ± 0.6 mm−1, whereas, in the apoptotic cells, an increase to 6.4 ± 1.7 mm−1 was observed. The results from cultured cells, as presented in this study, indicate the ability of OCT to detect and differentiate between viable, apoptotic, and necrotic cells, based on their attenuation coefficient. This functional supplement to high-resolution OCT imaging can be of great clinical benefit, enabling on-line monitoring of tissues, e.g. for feedback in cancer treatment.
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Iyomasa DM, Garavelo I, Iyomasa MM, Watanabe IS, Issa JPM. Ultrastructural analysis of the low level laser therapy effects on the lesioned anterior tibial muscle in the gerbil. Micron 2009; 40:413-8. [PMID: 19269186 DOI: 10.1016/j.micron.2009.02.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Revised: 02/02/2009] [Accepted: 02/03/2009] [Indexed: 10/21/2022]
Abstract
Low level laser therapy (LLLT) is known for its positive results but studies on the biological and biomodulator characteristics of the effects produced in the skeletal muscle are still lacking. In this study the effects of two laser dosages, 5 or 10 J/cm(2), on the lesioned tibial muscle were compared. Gerbils previously lesioned by 100 g load impact were divided into three groups: GI (n=5) controls, lesion non-irradiated; GII (n=5), lesion irradiated with 5 J/cm(2) and GIII (n=5), lesion irradiated with 10 J/cm(2), and treated for 7 consecutive days with a laser He-Ne (lambda=633 nm). After intracardiac perfusion, the muscles were dissected and reduced to small fragments, post-fixed in 1% osmium tetroxide, dehydrated in increasing alcohol concentrations, treated with propylene oxide and embedded in Spurr resin at 60 degrees C. Ultrafine cuts examined on a transmission electron microscope (Jeol 1010) revealed in the control GI group a large number of altered muscle fibers with degenerating mitochondria, intercellular substance containing degenerating cell fragments and budding blood capillaries with underdeveloped endothelial cells. However, groups GII and GIII showed muscle fibers with few altered myofibrils, regularly contoured mitochondria, ample intermembrane spaces and dilated mitochondrial crests. The clean intercellular substance showed numerous collagen fibers and capillaries with multiple abluminal processes, intraluminal protrusions and several pinocytic vesicles in endothelial cells. It was concluded that laser dosages of 5 or 10 J/cm(2) delivered by laser He-Ne (lambda=633 nm) during 7 consecutive days increase mitochondrial activity in muscular fibers, activate fibroblasts and macrophages and stimulate angiogenesis, thus suggesting effectivity of laser therapy under these experimental conditions.
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On the mechanism of organelle degradation in the vertebrate lens. Exp Eye Res 2008; 88:133-9. [PMID: 18840431 DOI: 10.1016/j.exer.2008.08.017] [Citation(s) in RCA: 163] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2008] [Revised: 08/22/2008] [Accepted: 08/26/2008] [Indexed: 11/20/2022]
Abstract
The programmed elimination of cytoplasmic organelles occurs during terminal differentiation of erythrocytes, keratinocytes and lens fiber cells. In each case, the process is relatively well understood phenomenologically, but the underlying molecular mechanisms have been surprisingly slow to emerge. This brief review considers the particular case of the lens where, in addition to their specialized physiological roles, organelles represent potential sources of light scattering. The article describes how the elimination of organelles from lens cells located on the visual axis contributes to the transparency of lens tissue. Classic anatomical studies of lens organelle degradation are discussed, along with more contemporary work utilizing confocal microscopy and other imaging modalities. Finally, recent data on the biochemistry of organelle degradation are reviewed. Several review articles on lens organelle degradation are available [Wride, M.A., 1996. Cellular and molecular features of lens differentiation: a review of recent advances. Differentiation 61, 77-93; Wride, M.A., 2000. Minireview: apoptosis as seen through a lens. Apoptosis 5, 203-209; Bassnett, S., 2002. Lens organelle degradation. Exp. Eye Res. 74, 1-6; Dahm, R., 2004. Dying to see. Sci. Am. 291, 82-89] and readers are directed to these for a comprehensive discussion of the earlier literature on this topic.
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Dai L, Qian Z, Li K, Yang T, Wang H. In vivo detection of reduced scattering coefficient of C6 glioma in rat brain tissue by near-infrared spectroscopy. JOURNAL OF BIOMEDICAL OPTICS 2008; 13:044003. [PMID: 19021331 DOI: 10.1117/1.2957974] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The purpose of this study is to investigate the reduced scattering coefficient of C6 glioma by the near-infrared (NIR) technique. Light scattering properties of C6 glioma in brain tissue is measured by NIR spectroscopy within the wavelength range from 700 to 850 nm. C6 gliomas were implanted in rats' right brains. The scattering properties of the left and right target corresponding to the position of normal and tumor tissue were measured by a bifurcated needle probe on postoperative days 3, 10, and 17. The results show that there was no significant difference in reduced scattering coefficient between left and right brain tissue at postoperative day 3, but significant decreases were found between left and right brains at postoperative days 10 and 17. This study proved our initial hypothesis that the NIR technique may have a potential for clinical application in brain muglioma diagnosis.
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Affiliation(s)
- Lijuan Dai
- Nanjing University of Aeronautics and Astronautics, Department of Biomedical Engineering, No. 29 Yuado Street, Nanjing, Jiangsu 210016, China
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Barrionuevo WR, Filho ECM, Bagnato VS. Enhanced visualization of histological samples with an adjustable RGB contrast system with application for tissue used in photodynamic therapy. Microsc Res Tech 2008; 71:403-8. [PMID: 18240325 DOI: 10.1002/jemt.20560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The analysis of histological sections has long been a valuable tool in the pathological studies. The interpretation of tissue conditions, however, relies directly on visual evaluation of tissue slides, which may be difficult to interpret because of poor contrast or poor color differentiation. The Chromatic Contrast Visualization System (CCV) combines an optical microscope with electronically controlled light-emitting diodes (LEDs) in order to generate adjustable intensities of RGB channels for sample illumination. While most image enhancement techniques rely on software post-processing of an image acquired under standard illumination conditions, CCV produces real-time variations in the color composition of the light source itself. The possibility of covering the entire RGB chromatic range, combined with the optical properties of the different tissues, allows for a substantial enhancement in image details. Traditional image acquisition methods do not exploit these visual enhancements which results in poorer visual distinction among tissue structures. Photodynamic therapy (PDT) procedures are of increasing interest in the treatment of several forms of cancer. This study uses histological slides of rat liver samples that were induced to necrosis after being exposed to PDT. Results show that visualization of tissue structures could be improved by changing colors and intensities of the microscope light source. PDT-necrosed tissue samples are better differentiated when illuminated with different color wavelengths, leading to an improved differentiation of cells in the necrosis area. Due to the potential benefits it can bring to interpretation and diagnosis, further research in this field could make CCV an attractive technique for medical applications.
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Lubart R, Landau Z, Jacobi J, Friedmann H. A NEW APPROACH TO ULCER TREATMENT USING BROADBAND VISIBLE LIGHT. Laser Ther 2007. [DOI: 10.5978/islsm.16.7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Bartek M, Wang X, Wells W, Paulsen KD, Pogue BW. Estimation of subcellular particle size histograms with electron microscopy for prediction of optical scattering in breast tissue. JOURNAL OF BIOMEDICAL OPTICS 2006; 11:064007. [PMID: 17212530 DOI: 10.1117/1.2398903] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Diffuse near-infrared tomography of tissue reveals scattering changes that originate from the submicroscopic features of the tissue; yet the existing tools to use this information to predict which features contribute to the scattering spectrum are limited by the lack of direct data quantifying the particle sizes. Breast tissue was examined with electron microscopy, and analysis showed that the distributions of particle sizes appear in double exponential functions for most cellular tissues. The average particle size histograms of high-grade cancer, low-grade cancer, fibroglandular tissue, and adipose tissue were examined. The particle histograms were progressively decreasing in magnitude for these tissue types, and the average size of the particles increased, for these four tissues, respectively. Typical particle sizes in the range of 10 to 500 nm for these tissue types, with biexponential fitting, gave two particle distributions: one near 20 to 25 nm for the smaller size and one at 110 to 230 nm for the larger distributions. Mie scatter theory was used to take these particle distributions and calculate scattering spectra. The ability to image reduced scattering coefficient spectra of bulk breast tissues exists, and so this data provides insight into how bulk imaging may be mapped over to predict factors related to the tissue ultrastructure.
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Affiliation(s)
- Matthew Bartek
- Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755, USA
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Abstract
Understanding wound healing today involves much more than simply stating that there are three phases: inflammation, proliferation, and maturation. Wound healing is a complex series of reactions and interactions among cells and "mediators." Each year, new mediators are discovered and our understanding of inflammatory mediators and cellular interactions grows. This article will attempt to provide a concise overview on wound healing and wound management.
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Affiliation(s)
- George Broughton
- Department of Plastic Surgery, Nancy L & Perry Bass Advanced Wound Healing Laboratory, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9132, USA.
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Desmet KD, Paz DA, Corry JJ, Eells JT, Wong-Riley MTT, Henry MM, Buchmann EV, Connelly MP, Dovi JV, Liang HL, Henshel DS, Yeager RL, Millsap DS, Lim J, Gould LJ, Das R, Jett M, Hodgson BD, Margolis D, Whelan HT. Clinical and Experimental Applications of NIR-LED Photobiomodulation. Photomed Laser Surg 2006; 24:121-8. [PMID: 16706690 DOI: 10.1089/pho.2006.24.121] [Citation(s) in RCA: 217] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
This review presents current research on the use of far-red to near-infrared (NIR) light treatment in various in vitro and in vivo models. Low-intensity light therapy, commonly referred to as "photobiomodulation," uses light in the far-red to near-infrared region of the spectrum (630-1000 nm) and modulates numerous cellular functions. Positive effects of NIR-light-emitting diode (LED) light treatment include acceleration of wound healing, improved recovery from ischemic injury of the heart, and attenuated degeneration of injured optic nerves by improving mitochondrial energy metabolism and production. Various in vitro and in vivo models of mitochondrial dysfunction were treated with a variety of wavelengths of NIR-LED light. These studies were performed to determine the effect of NIR-LED light treatment on physiologic and pathologic processes. NIRLED light treatment stimulates the photoacceptor cytochrome c oxidase, resulting in increased energy metabolism and production. NIR-LED light treatment accelerates wound healing in ischemic rat and murine diabetic wound healing models, attenuates the retinotoxic effects of methanol-derived formic acid in rat models, and attenuates the developmental toxicity of dioxin in chicken embryos. Furthermore, NIR-LED light treatment prevents the development of oral mucositis in pediatric bone marrow transplant patients. The experimental results demonstrate that NIR-LED light treatment stimulates mitochondrial oxidative metabolism in vitro, and accelerates cell and tissue repair in vivo. NIR-LED light represents a novel, noninvasive, therapeutic intervention for the treatment of numerous diseases linked to mitochondrial dysfunction.
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Affiliation(s)
- Kristina D Desmet
- Department of Clinical Laboratory Sciences, University of Wisconsin-Milwaukee, 53226, USA
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Holmer C, Lehmann KS, Risk J, Roggan A, Germer CT, Reissfelder C, Isbert C, Buhr HJ, Ritz JP. Colorectal tumors and hepatic metastases differ in their optical properties—relevance for dosimetry in laser-induced interstitial thermotherapy. Lasers Surg Med 2006; 38:296-304. [PMID: 16526042 DOI: 10.1002/lsm.20300] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND OBJECTIVES The therapeutic application of laser light is a promising alternative to surgical resection of colorectal liver metastases. The extent of tumor destruction achieved by this strategy depends primarily on light distribution in the target tissue. Knowledge about optical properties is necessary to predict light distribution in the tissue for careful irradiation planning. The aim of this study was to compare the optical behavior of healthy colon tissue with that of colorectal carcinomas and their hepatic metastases in the native and coagulated state in order to test the effect of malignant degeneration, metastasis, and thermal coagulation on optical parameters. MATERIALS AND METHODS Ninety tissue samples were taken from patients with a colorectal carcinoma and concomitant liver metastases: healthy colon tissue (n = 30); colon carcinoma (n = 30); liver metastases (n = 30). Optical properties were measured according to the single integrating sphere principle in the native state and after thermal coagulation in the wavelength range of 800-1,100 nm and analyzed by inverse Monte Carlo simulation. RESULTS The highest optical penetration depth for all tissue types was obtained at the end of the spectral range investigated. The highest penetration depths of 4.13 mm (healthy colon), 7.47 mm (colon carcinoma tissue), and 4.08 (liver metastases) were at 1,060 nm, although the values decreased significantly after thermal coagulation. Comparing healthy colon-to-colon carcinoma always revealed a significantly lower absorption and scattering coefficient in the tumor tissue. This resulted in a higher optical penetration depth of the laser light in the colon carcinoma tissue (P < 0.05). A direct comparison disclosed no agreement between the optical properties of the primary tumor and the liver metastases. In the native state, colon carcinoma tissue had a lower scattering coefficient (P < 0.05), higher anisotropy factor, and optical penetration depth than liver metastases (P < 0.05). The absorption coefficient did not differ significantly. The differences in the native state were equalized by tissue coagulation. CONCLUSIONS Colon carcinoma tissue has a higher optical penetration depth than healthy colon tissue, which speaks in favor of tumor selectivity for interstitial laser application, since large treatment volumes can be obtained in the tumor. The lack of agreement between primary tumors and their concomitant liver metastases indicates a modification of optical behavior through metastasis. Thermal coagulation of tissue leads to changes in the optical properties, which are clearly less pronounced in carcinoma tissue. The data obtained in this study clearly show that an individual irradiation schedule is necessary for effective and safe dosimetry in laser-induced thermotherapy (LITT).
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Affiliation(s)
- Christoph Holmer
- Department of General, Vascular and Thoracic Surgery, Charité-Campus Benjamin Franklin, Berlin, Germany
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Ramstein S, Vignal C, Mathevon N, Mottin S. In vivo and noninvasive measurement of a songbird head's optical properties. APPLIED OPTICS 2005; 44:6197-204. [PMID: 16237935 DOI: 10.1364/ao.44.006197] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
By assessing the cerebral blood volume and the hemoglobin oxygen saturation level, near-infrared spectroscopy (NIRS) probes brain oxygenation, which reflects cerebral activity. To develop a noninvasive method monitoring the brain of a songbird, we use an original NIRS device, i.e., a white laser coupled with an ultrafast spectrotemporal detector of optical signals without wavelength scanning. We perform in vivo measurements of the absorption coefficient and the reduced scattering coefficient of the caudal nidopallium area of the head of a songbird (the zebra finch).
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Affiliation(s)
- Stéphane Ramstein
- Laboratoire Traitement du Signal et Instrumentation, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5516, Université Jean Monnet, Saint-Etienne, France
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