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Britz L, Schickhardt SK, Auffarth GU, Khoramnia R. Opacification of Hydrophilic Acrylic Intraocular Lenses: Overview of Laboratory Methods for Histological Analysis and Replication of IOL Calcification. Klin Monbl Augenheilkd 2023; 240:960-970. [PMID: 37391183 DOI: 10.1055/a-2073-8526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/02/2023]
Abstract
Opacification of intraocular lenses (IOLs) due to material changes is a serious complication that can compromise the good visual outcomes of uncomplicated cataract surgery. In hydrophobic acrylic IOLs, opacification can result from glistening formation, while in hydrophilic acrylic IOLs, there is a risk of calcification due to the formation of calcium phosphates within the polymer. Over time, various methods have been developed to investigate calcification in hydrophilic acrylic IOLs. The aim of this article is to provide an overview of standard histological staining and models used to simulate IOL calcification. Histological staining can be used to detect calcification and assess the extent of crystal formation. The development of in vivo and in vitro replication models has helped to identify the underlying pathomechanisms of calcification. In vivo models are suitable for assessing the biocompatibility of IOL materials. Bioreactors as an in vitro model can be used to investigate the kinetics of crystal formation within the polymer. The replication of IOL calcification under standardized conditions using electrophoresis allows for the comparison of different lens materials with respect to the risk of calcification. The combination of different analytical and replication methods can be used in the future to further investigate the pathomechanisms of calcium phosphate crystal formation and the influence of risk factors. This may help to prevent calcification of hydrophilic acrylic IOLs and associated explantation and complications.
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Affiliation(s)
- Leoni Britz
- Universitäts-Augenklinik, UniversitätsKlinikum Heidelberg, Deutschland
| | | | - Gerd U Auffarth
- Universitäts-Augenklinik, UniversitätsKlinikum Heidelberg, Deutschland
| | - Ramin Khoramnia
- International Vision Correction Research Centre (IVCRC) und David J Apple International Laboratory for Ocular Pathology, Univ.-Augenklinik Heidelberg, Deutschland
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Britz L, Schickhardt SK, Yildirim TM, Auffarth GU, Lieberwirth I, Khoramnia R. Development of a standardized in vitro model to reproduce hydrophilic acrylic intraocular lens calcification. Sci Rep 2022; 12:7685. [PMID: 35538104 PMCID: PMC9090772 DOI: 10.1038/s41598-022-11486-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 04/07/2022] [Indexed: 11/20/2022] Open
Abstract
Opacification through calcification of hydrophilic acrylic intraocular lenses (IOL) is a severe complication after cataract surgery. Causing symptoms that range from glare through to severe vision loss, the only effective therapy is explantation of the opacified IOL so far. Although IOL calcification is a well-described phenomenon, its pathogenesis is not fully understood yet. The purpose of the current study was to develop a laboratory model to replicate IOL calcification. Calcification could be reproduced using a horizontal electrophoresis and aqueous solutions of calcium chloride and disodium hydrogen phosphate. The analysis of the in vitro calcified IOLs was performed using light microscopy, Alizarin Red and Von Kossa staining, scanning electron microscopy, energy dispersive x-ray spectroscopy and electron crystallography using transmission electron microscopy and electron diffraction. The presented laboratory model could be used to identify hydrophilic IOLs that are at risk to develop calcification and to assess the influence of associated risk factors. In addition, it can serve as a research tool to further understand this pathology.
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Affiliation(s)
- Leoni Britz
- The David J. Apple International Laboratory for Ocular Pathology, Department of Ophthalmology, University Eye Clinic Heidelberg, University of Heidelberg, INF 400, 69120, Heidelberg, Germany
| | - Sonja Katrin Schickhardt
- The David J. Apple International Laboratory for Ocular Pathology, Department of Ophthalmology, University Eye Clinic Heidelberg, University of Heidelberg, INF 400, 69120, Heidelberg, Germany
| | - Timur Mert Yildirim
- The David J. Apple International Laboratory for Ocular Pathology, Department of Ophthalmology, University Eye Clinic Heidelberg, University of Heidelberg, INF 400, 69120, Heidelberg, Germany
| | - Gerd Uwe Auffarth
- The David J. Apple International Laboratory for Ocular Pathology, Department of Ophthalmology, University Eye Clinic Heidelberg, University of Heidelberg, INF 400, 69120, Heidelberg, Germany.
| | - Ingo Lieberwirth
- Department of Physical Chemistry of Polymers, Max Planck Institute for Polymer Research, Mainz, Germany
| | - Ramin Khoramnia
- The David J. Apple International Laboratory for Ocular Pathology, Department of Ophthalmology, University Eye Clinic Heidelberg, University of Heidelberg, INF 400, 69120, Heidelberg, Germany
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Cosmidis J, Benzerara K, Nassif N, Tyliszczak T, Bourdelle F. Characterization of Ca-phosphate biological materials by scanning transmission X-ray microscopy (STXM) at the Ca L2,3-, P L2,3- and C K-edges. Acta Biomater 2015; 12:260-269. [PMID: 25305511 DOI: 10.1016/j.actbio.2014.10.003] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2014] [Revised: 08/19/2014] [Accepted: 10/02/2014] [Indexed: 02/05/2023]
Abstract
Several naturally occurring biological materials, including bones and teeth, pathological calcifications, microbial mineral deposits formed in marine phosphogenesis areas, as well as bio-inspired cements used for bone and tooth repair are composed of Ca-phosphates. These materials are usually identified and characterized using bulk-scale analytical tools such as X-ray diffraction, Fourier transform infrared spectroscopy or nuclear magnetic resonance. However, there is a need for imaging techniques that provide information on the spatial distribution and chemical composition of the Ca-phosphate phases at the micrometer- and nanometer scales. Such analyses provide insightful indications on how the materials may have formed, e.g. through transient precursor phases that eventually remain spatially separated from the mature phase. Here, we present scanning transmission X-ray microscopy (STXM) analyses of Ca-phosphate reference compounds, showing the feasibility of fingerprinting Ca-phosphate-based materials. We calibrate methods to determine important parameters of Ca-phosphate phases, such as their Ca/P ratio and carbonate content at the ∼25nm scale, using X-ray absorption near-edge spectra at the C K-, Ca L2,3- and P L2,3-edges. As an illustrative case study, we also perform STXM analyses on hydroxyapatite precipitates formed in a dense fibrillar collagen matrix. This study paves the way for future research on Ca-phosphate biomineralization processes down to the scale of a few tens of nanometers.
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Affiliation(s)
- Julie Cosmidis
- Institut de Minéralogie, de Physique des Matériaux, et de Cosmochimie (IMPMC), Sorbonne Universités, Univ Paris 06, CNRS UMR 7590, MNHN, IRD UMR 206, F-75252 Paris 05, France
| | - Karim Benzerara
- Institut de Minéralogie, de Physique des Matériaux, et de Cosmochimie (IMPMC), Sorbonne Universités, Univ Paris 06, CNRS UMR 7590, MNHN, IRD UMR 206, F-75252 Paris 05, France.
| | - Nadine Nassif
- Lab Chim Matière Condensée (LMCM), Univ Paris 06, Coll France, CNRS UMR 7574, F-75231 Paris 05, France
| | - Tolek Tyliszczak
- Lawrence Berkeley National Laboratory, Advanced Light Source, Berkeley, CA 94720 USA
| | - Franck Bourdelle
- Lab Génie Civil et géo-Environnement (LGCgE), Univ Lille 1, SN5, 59655 Villeneuve-d'Ascq, France
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Opacification of hydrophilic acrylic intraocular lens attributable to calcification: investigation on mechanism. Am J Ophthalmol 2008; 146:395-403. [PMID: 18602078 DOI: 10.1016/j.ajo.2008.04.032] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2007] [Revised: 04/22/2008] [Accepted: 04/22/2008] [Indexed: 10/21/2022]
Abstract
PURPOSE To identify the nature and to investigate the biochemical mechanisms leading to late opacification of implanted hydrophilic acrylic intraocular lenses (IOLs). DESIGN Retrospective laboratory investigation. METHODS setting: Department of Ophthalmology, Medical School, Department of Chemical Engineering, Laboratory of Inorganic and Analytical Chemistry, University of Patras and FORTH-ICEHT, Greece. study population: Thirty IOLs were explanted one to 12 years postimplantation attributable to gradual opacification of the lens material. observation procedures: Materials analysis was done using scanning electron microscopy (SEM) equipped with a microanalysis probe (EDS), confocal microscopy, x-ray diffraction (XRD), and Fourier transform infrared (FTIR) for the identification of the substances involved in the opacified lenses. RESULTS SEM investigation showed plate-like as well as prismatic nanoparticle deposits of calcium phosphate crystallites on the surface and in the interior of opacified IOLs. The plate-like deposits exhibited morphology and particle size typical for octacalcium phosphate (OCP), while the respective characteristics of the prismatic nanocrystals were typical of hydroxyapatite (HAP). EDS analysis confirmed the chemical composition of the deposits. Aqueous humor analysis showed that the humor is supersaturated with respect to both OCP and HAP, favoring the formation of the thermodynamically more stable HAP, while the formation and kinetic stabilization of other transient phases is also very likely. In vitro experiments using polyacrylic materials confirmed the clinical findings. CONCLUSIONS Hydrophilic acrylic IOLs' opacification may be attributed to the deposition of calcium phosphate crystallites. HAP is the predominant crystalline phase of these crystallites. Surface hydroxyl groups of the polyacrylic materials facilitate surface nucleation and growth.
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Yang DC, Tsay HJ, Lin SY, Chiou SH, Li MJ, Chang TJ, Hung SC. cAMP/PKA regulates osteogenesis, adipogenesis and ratio of RANKL/OPG mRNA expression in mesenchymal stem cells by suppressing leptin. PLoS One 2008; 3:e1540. [PMID: 18253488 PMCID: PMC2212109 DOI: 10.1371/journal.pone.0001540] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2007] [Accepted: 01/11/2008] [Indexed: 12/16/2022] Open
Abstract
Background Mesenchymal stem cells (MSCs) are a pluripotent cell type that can differentiate into adipocytes, osteoblasts and other cells. The reciprocal relationship between adipogenesis and osteogenesis was previously demonstrated; however, the mechanisms remain largely unknown. Methods and Findings We report that activation of PKA by 3-isobutyl-1 methyl xanthine (IBMX) and forskolin enhances adipogenesis, the gene expression of PPARγ2 and LPL, and downregulates the gene expression of Runx2 and osteopontin, markers of osteogenesis. PKA activation also decreases the ratio of Receptor Activator of the NF-κB Ligand to Osteoprotegerin (RANKL/OPG) gene expression – the key factors of osteoclastogenesis. All these effects are mediated by the cAMP/PKA/CREB pathway by suppressing leptin, and may contribute to PKA stimulators-induced in vivo bone loss in developing zebrafish. Conclusions Using MSCs, the center of a newly proposed bone metabolic unit, we identified cAMP/PKA signaling, one of the many signaling pathways that regulate bone homeostasis via controlling cyto-differentiation of MSCs and altering RANKL/OPG gene expression.
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Affiliation(s)
- Der-Chih Yang
- Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan
- Department of Medical Research and Education, Veterans General Hospital - Taipei, National Yang-Ming University, Taipei, Taiwan
| | - Huey-Jen Tsay
- Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan
| | - Shan-Yang Lin
- Department of Medical Research and Education, Veterans General Hospital - Taipei, National Yang-Ming University, Taipei, Taiwan
| | - Shih-Hwa Chiou
- Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan
- Department of Medical Research and Education, Veterans General Hospital - Taipei, National Yang-Ming University, Taipei, Taiwan
| | - Mei-Jane Li
- Department of Medical Research and Education, Veterans General Hospital - Taipei, National Yang-Ming University, Taipei, Taiwan
| | - Tai-Jay Chang
- Department of Medical Research and Education, Veterans General Hospital - Taipei, National Yang-Ming University, Taipei, Taiwan
| | - Shih-Chieh Hung
- Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan
- Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan
- Department of Medical Research and Education, Veterans General Hospital - Taipei, National Yang-Ming University, Taipei, Taiwan
- Department of Orthopaedics and Traumatology, Veterans General Hospital - Taipei, National Yang-Ming University, Taipei, Taiwan
- * To whom correspondence should be addressed. E-mail:
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Lin SY, Chen KH, Cheng WT, Ho CT, Wang SL. Preliminary identification of Beta-carotene in the vitreous asteroid bodies by micro-Raman spectroscopy and HPLC analysis. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2007; 13:128-32. [PMID: 17367552 DOI: 10.1017/s143192760707002x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2006] [Accepted: 09/12/2006] [Indexed: 05/14/2023]
Abstract
beta-carotene was first identified from the vitreous asteroid bodies (ABs) excised from one patient with asteroid hyalosis (AH) by confocal Raman microspectroscopy and was also verified by high performance liquid chromatography (HPLC). Two patients had been diagnosed with AH and intervened by surgical vitrectomy due to blurred vision. The morphology and components of both AB specimens were observed by optical microscopy and determined by using confocal Raman microspectroscopy and HPLC analysis, respectively. Surprisingly, two unique peaks at 1528 and 1157 cm(-1) were found in the Raman spectrum for the AB specimen of patient 1 alone, which were in close agreement with that of the Raman peaks at 1525 and 1158 cm(-1) for beta-carotene and/or lutein. However, HPLC analytical data clearly indicated that the retention time for the extracted sample from the AB specimen of patient 1 was observed at 13.685 min and just identical to that of beta-carotene (13.759 min) rather than lutein (2.978 min). In addition, the lack of any peak in the HPLC profile for the AB specimen of patient 2 also confirmed the absence of Raman peaks at 1525 and 1158 cm(-1). Thus this preliminary study strongly suggests that beta-carotene as a unique component of ABs was specifically detected from the AB specimen of one AH patient by using confocal Raman microspectroscopy and HPLC analysis.
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Affiliation(s)
- Shan-Yang Lin
- Department of Medical Research & Education, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China.
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Jalota S, Bhaduri SB, Tas AC. Osteoblast proliferation on neat and apatite-like calcium phosphate-coated titanium foam scaffolds. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2007. [DOI: 10.1016/j.msec.2006.05.052] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Jalota S, Bhaduri SB, Tas AC. A new rhenanite (β-NaCaPO4) and hydroxyapatite biphasic biomaterial for skeletal repair. J Biomed Mater Res B Appl Biomater 2007; 80:304-16. [PMID: 16767721 DOI: 10.1002/jbm.b.30598] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Biphasic beta-rhenanite (beta-NaCaPO(4))-hydroxyapatite (Ca(10)(PO(4))(6)(OH)(2)) biomaterials were prepared by using a one-pot, solution-based synthesis procedure at the physiological pH of 7.4, followed by low-temperature (300-600 degrees C) calcination in air for 6 h. Calcination was for the sole purpose of crystallization. An aqueous solution of Ca(NO(3))(2). 4H(2)O was rapidly added to a solution of Na(2)HPO(4) and NaHCO(3), followed by immediate removal of gel-like, poorly-crystallized precursor precipitates from the mother liquors of pH 7.4. Freeze-dried precursors were found to be nanosize with an average particle size of 45 nm and a surface area of 128 m(2)/g. Upon calcination in air, precursor powders crystallized into biphasic (60% HA-40% rhenanite) biomaterials, while retaining their submicron particle sizes and high surface areas. beta-rhenanite is a high solubility sodium calcium phosphate phase. Samples were characterized by XRD, FTIR, SEM, TEM, ICP-AES, TG, DTA, DSC, and surface area measurements.
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Affiliation(s)
- Sahil Jalota
- School of Materials Science and Engineering, Clemson University, Clemson, South Carolina 29634, USA
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Cheng WT, Liu MT, Liu HN, Lin SY. Micro-Raman spectroscopy used to identify and grade human skin pilomatrixoma. Microsc Res Tech 2006; 68:75-9. [PMID: 16228983 DOI: 10.1002/jemt.20229] [Citation(s) in RCA: 206] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Raman microspectroscopy was applied to analyze the changes in structural conformation and chemical composition of the mass of human skin pilomatrixoma (PMX). The normal skin dermis, collagen type I, and hydroxyapatite (HA) were used as control. The excised specimens from two patients diagnosed as a typical PMX were detected, in which one specimen was a soft mass, but the other was a hard mass with somewhat calcified deposits via histopathological examination. The Raman spectrum of normal skin dermis was found to be similar to the Raman spectrum of collagen type I, confirming that the collagen type I was a predominant component in normal skin dermis. The differences of Raman peak intensity between normal skin dermis and soft or hard PMX mass were obvious at 1,622-1,558, 1,400-1,230, 1,128, 1,000-850, 749, and 509 cm(-1). In particular, the peak at 1,665 cm(-1) assigned to amide I band shifted to 1,655 cm(-1) and the peak at 1,246 cm(-1) corresponding to amide III band was reduced in its intensity in hard PMX mass. The significant changes in collagen content and its structural conformation, the higher content of tryptophan, and disulfide formation in PMX masses were markedly evidenced. In addition, the shoulder and weak peak at 960 cm(-1) assigned to the stretching vibration of PO(4) (3-) of HA also appeared respectively in the Raman spectra of soft and hard PMX masses, suggesting the occurrence of calcification of HA in the PMX tissue, particularly in the hard PMX mass. The result indicates that the micro-Raman spectroscopy may provide a highly sensitive and specific method for identifying normal skin dermis and how it differs in chemical composition from different PMX tissues.
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Affiliation(s)
- Wen-Ting Cheng
- Department of Medical Research and Education, Taipei Veterans General Hospital, Taiwan, Republic of China
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Liu MT, Cheng WT, Li MJ, Liu HN, Yang DM, Lin SY. Identification of chemical compositions of skin calcified deposit by vibrational microspectroscopies. Arch Dermatol Res 2005; 297:231-4. [PMID: 16231145 DOI: 10.1007/s00403-005-0614-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2005] [Revised: 09/19/2005] [Accepted: 09/21/2005] [Indexed: 10/25/2022]
Abstract
Calcinosis cutis is characterized by the deposition of calcium salts in the subcutaneous tissues. Both Fourier transform infrared (FTIR) and Raman microspectroscopic analysis have been applied to easily get the chemical compositions of the skin calcified deposit (SCD), which was surgically excised from a female patient. This SCD was cut into two parts for histopathological (H&E stain) examination and vibrational microspectroscopic study. The result indicates that the whole SCD in the skin lesion was found to be a well-developed, mature and hard mass. Several FTIR absorption bands at 873, 961 and 1,031 cm(-1) [the stretching modes of carbonate and phosphate of hydroxyapatite (HA)], 1,547 and 1,658 cm(-1) (the amide I and II bands of collagen) were detected in the IR spectrum of SCD. The Raman spectral bands at 1,665 and 1,450 cm(-1) (collagen); 1,519 and 1,156 cm(-1) (beta-carotene); and 1,072 and 958 cm(-1) (HA) were also obtained. To our knowledge, this is the first report using FTIR and Raman microspectroscopies to quickly identify and quantify three predominant components, collagen, beta-carotene and type B carbonated HA, in the SCD of a patient.
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Affiliation(s)
- Ming-Tzen Liu
- Department of Dermatology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
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Chen KH, Cheng WT, Li MJ, Lin SY. Corneal calcification: chemical composition of calcified deposit. Graefes Arch Clin Exp Ophthalmol 2005; 244:407-10. [PMID: 16133012 DOI: 10.1007/s00417-005-1191-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2005] [Revised: 03/24/2005] [Accepted: 03/30/2005] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND The aim of this study was to quickly and quantitatively detect the chemical composition of the calcified deposit on the surface of a surgically excised cornea by using vibrational microspectroscopy. METHODS Both attenuated total reflection (ATR)/Fourier transform infrared (FTIR) and confocal Raman microspectroscopies were used to evaluate the chemical composition of the excised corneal calcified opaque deposit of a 50-year-old male patient. Hydroxyapatite (HA) was used as a reference. RESULTS Microscopic observations indicated that a whitish-grayish opaque plaquelike deposit was observed. A peak at 1020 cm(-1) assigned to the stretching vibration of phosphate of the poorly crystalline, immature and nonstoichiometric HA was observed from the IR spectrum of the corneal calcified deposit, as compared with the peak at 1030 cm(-1) of the mature, crystalline and stoichiometric HA reference sample. Higher contents of two IR spectral peaks at 871 cm(-1) due to the type-B carbonated apatite and at 866 cm(-1) corresponded to a labile carbonate were also evidenced in the corneal calcified deposit. The predominate peak at 959 cm(-1) due to the stretching mode of phosphate was also found in the Raman spectrum of corneal calcified deposit. CONCLUSIONS The corneal calcified deposit was evidenced to contain much poor crystalline and immature HA having higher content of the type-B carbonated apatite within the corneal collagen matrix. The process of corneal calcification still proceeds on the surface of this cornea.
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Affiliation(s)
- Ko-Hua Chen
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China
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Chen KH, Cheng WT, Li MJ, Yang DM, Lin SY. Calcification of senile cataractous lens determined by Fourier transform infrared (FTIR) and Raman microspectroscopies. J Microsc 2005; 219:36-41. [PMID: 15998364 DOI: 10.1111/j.1365-2818.2005.01491.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A calcified plaque on the surface of a senile cataractous lens (CL) isolated from a 79-year-old male patient was identified and its chemical composition quantified using Fourier transform infrared (FTIR) and confocal Raman microspectroscopies. The noncalcified area of the same CL and hydroxyapatite (HA) were selected as a control. Several unique absorption bands, at 960, 1034 and 1090 cm(-1) assigned to the nu(1) and nu(3) stretching modes of phosphate and at 875 cm(-1) attributed to carbonate, were clearly displayed in the infrared (IR) spectra of calcified plaque and HA. A peak at 961 cm(-1) due to the nu(1) stretching mode of phosphate was also evidenced in the Raman spectra of calcified plaque and HA. The calcified plaque formed within the lens protein was found to mainly consist of a mature HA, in which type-A carbonate apatites (11.4%), type-B carbonate apatites (55.6%) and liable surface carbonate ions (33.0%) were presented. A higher content of the liable carbonate implies that the calcification or mineralization in this calcified lens was incomplete and still in progress. Moreover, calcification seems not to influence the secondary structure of lens protein because both IR and Raman spectra for the lens protein in the noncalcified area and calcified plaque were similar. The result suggests that both microscopic FTIR and Raman spectroscopies were easy to perform and capable of determination of the chemical composition of a calcified CL.
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Affiliation(s)
- K-H Chen
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China
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Lai JY, Chen KH, Hsu WM, Lee TH, Lin SY. Multiple elements in the deposits of opacified Hydroview intraocular lens. Am J Ophthalmol 2005; 139:1123-5. [PMID: 15953454 DOI: 10.1016/j.ajo.2004.11.052] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2004] [Accepted: 11/24/2004] [Indexed: 11/30/2022]
Abstract
PURPOSE To report the ultrastructural and elemental features of two opacified intraocular lenses (IOLs). DESIGN Histopathologic case series. METHODS Two opaque hydrophilic acrylic IOLs (Hydroview H60M, Bausch & Lomb Surgical Clearwater, Florida, USA) explanted from two Chinese patients in Taiwan. The explanted IOLs were evaluated by light microscopy, scanning electron microscopy, and energy-dispersive x-ray spectroscopy. RESULTS Brownish granular and scattered crystal-like deposits were found in case 2, whereas only fine white granular deposits were found in case 1. Using EDX spectroscopy, the elements of deposits on IOL optics were calcium and phosphorus in case 1, but in case 2, fluorine, magnesium, and sodium were demonstrated in addition to calcium and phosphorus. CONCLUSIONS Our study indicated a difference in morphology and elements of deposits on opaque IOL optics between these two cases. It was suggested that multiple elements may contribute to the formation of deposits.
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Affiliation(s)
- Jui-Yang Lai
- Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan, Republic of China
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Li MJ, Lin SY. Vibrational Spectroscopic Studies on the Disulfide Formation and Secondary Conformational Changes of Captopril–HSA Mixture after UV-B Irradiation. Photochem Photobiol 2005; 81:1404-10. [PMID: 16354113 DOI: 10.1562/2005-04-25-rn-497] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The effects of pH and ultraviolet-B (UV-B) irradiation on the secondary structure of human serum albumin (HSA) in the absence or presence of captopril were investigated by an attenuated total reflection (ATR)/Fourier transform infrared (FTIR) spectroscopy. The UV-B exposure affecting the stability of captopril before and after captopril-HSA interaction was also examined by using confocal Raman microspectroscopy. The results indicate that the transparent pale-yellow solution for captopril-HSA mixture in all pH buffer solutions, except pH 5.0 approximately 7.0, changed into a viscous form then a gel form with UV-B exposure time. The secondary structural transformation of HSA in the captopril-HSA mixture with or without UV-B irradiation was found to shift the maxima amide I peak in IR spectra from 1652 cm(-1) assigned to alpha-helix structure to 1622 cm(-1) because of a beta-sheet structure, which was more evident in pH 3.0, 8.0 or 9.0 buffer solutions. The Raman shift from 1653 cm(-1) (alpha-helix) to 1670 cm(-1) (beta-sheet) also confirmed this result. Captopril dissolved in distilled water with or without UV-B irradiation was determined to form a captopril disulfide observed from the Raman spectra of 512 cm(-1), which was exacerbated by UV-B irradiation. There was little disulfide formation in the captopril-HSA mixture even with long-term UV-B exposure, but captopril might interact with HSA to change the protein secondary structure of HSA whether there was UV-B irradiation or not. The pH of the buffer solution and captopril-HSA interaction may play more important roles in transforming the secondary structure of HSA from alpha-helix to beta-sheet in the corresponding captopril-HSA mixture than UV-B exposure. The present study also implies that HSA has the capability to protect the instability of captopril in the course of UV-B irradiation. In addition, a partial unfolding of HSA induced by pH or captopril-HSA interaction under UV-B exposure is proposed.
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Affiliation(s)
- Mei-Jane Li
- Biopharmaceutics Laboratory, Department of Medical Research and Education, Taipei Veterans General Hospital, Shih-Pai, Taipei, Taiwan, Republic of China
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