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Shi R, Wu Y, Chen H, Zhang Z, Bao S, Qu J, Zhou M. The causal effect of oxidative stress on the risk of glaucoma. Heliyon 2024; 10:e24852. [PMID: 38317903 PMCID: PMC10838757 DOI: 10.1016/j.heliyon.2024.e24852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 12/09/2023] [Accepted: 01/16/2024] [Indexed: 02/07/2024] Open
Abstract
Glaucoma is a complex multifactorial disease. Oxidative stress has been implicated in its pathogenesis. However, establishing a causal relationship between oxidative stress and glaucoma is challenging due to confounding and reverse causality. In this study, we performed bidirectional two-sample Mendelian randomization (MR) analyses based on genetic instrumental variables as proxies for 11 biomarkers of oxidative stress injury to investigate the causal relationship between oxidative stress and glaucoma. Eight significant associations were identified. Increased circulating levels of catalase (OR = 0.915, 95 % CI: 0.848-0.987, P = 0.022), retinol (OR = 0.481, 95 % CI: 0.248-0.932, P = 0.044) and superoxide dismutase (OR = 0.779, 95 % CI: 0. 616-0.986, P = 0.038) are associated with a decreased risk of glaucoma, whereas an increased myeloperoxidase level (OR = 2.145, 95 % CI: 1.119-4.111, P = 0.029) is associated with an increased risk of glaucoma. Glaucoma was causally associated with lower levels of total bilirubin (OR = 0.961, 95 % CI: 0.927-0.997, P = 0.039), glutathione peroxidase (OR = 0. 934, 95 % CI: 0.890-0.981, P = 0.006), paraoxonase (OR = 0.883, 95 % CI: 0.810-0.963, P = 0.005) and albumin (OR = 0.988, 95 % CI: 0.978-0.998, P = 0.014). The bidirectional MR analysis revealed a causal relationship between oxidative stress and glaucoma. These findings provide a greater understanding of the underlying mechanisms of glaucomatous neurodegeneration and imply a potential therapeutic approach for glaucoma through targeting oxidative stress pathways.
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Affiliation(s)
- Ronghua Shi
- School of Biomedical Engineering, School of Information and Communication Engineering, Hainan University, Haikou 570228, China
- Hainan Institute of Real World Data, Qionghai, 571437, China
| | - Yaxuan Wu
- School of Biomedical Engineering, School of Information and Communication Engineering, Hainan University, Haikou 570228, China
- Hainan Institute of Real World Data, Qionghai, 571437, China
| | - He Chen
- School of Biomedical Engineering, School of Information and Communication Engineering, Hainan University, Haikou 570228, China
- Hainan Institute of Real World Data, Qionghai, 571437, China
| | - Zicheng Zhang
- School of Biomedical Engineering, School of Information and Communication Engineering, Hainan University, Haikou 570228, China
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
- Hainan Institute of Real World Data, Qionghai, 571437, China
| | - Siqi Bao
- School of Biomedical Engineering, School of Information and Communication Engineering, Hainan University, Haikou 570228, China
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
- Hainan Institute of Real World Data, Qionghai, 571437, China
| | - Jia Qu
- School of Biomedical Engineering, School of Information and Communication Engineering, Hainan University, Haikou 570228, China
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
- Hainan Institute of Real World Data, Qionghai, 571437, China
| | - Meng Zhou
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
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Tenney S, Oboh-Weilke A, Wagner D, Chen MY. Tamoxifen retinopathy: A comprehensive review. Surv Ophthalmol 2024; 69:42-50. [PMID: 37482306 DOI: 10.1016/j.survophthal.2023.07.003] [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: 10/26/2022] [Revised: 07/03/2023] [Accepted: 07/10/2023] [Indexed: 07/25/2023]
Abstract
Tamoxifen is a selective estrogen receptor modulator used mainly for the treatment of breast cancer. Based on the case reports and studies performed to date on the retinal toxicity of tamoxifen, retinopathy appears to occur in as many as 12% of patients taking 20 mg tamoxifen a day for over 2 years. Of this 12%, as many as half develop symptomatic changes in visual acuity. Retinal changes consist primarily of crystalline deposits, cystoid macular edema, hyperreflective deposits in the inner retinal layers, and telangiectasia. Tamoxifen retinopathy is currently managed by discontinuing tamoxifen therapy as the cancer prognosis permits; however, discontinuing therapy demonstrates little to no improvement in visual acuity once visual changes have taken place. Intravitreal injections of steroids or antivascular endothelial growth factor therapy have been performed, but require further studying before conclusions can be made. Until then, optical coherence tomography screening for retinal changes should be performed every 6 months for patients who have been on tamoxifen therapy for 2 years or more. This way, patients can become aware of retinal changes, and their physicians can consider adjusting tamoxifen therapy before they risk developing changes in visual acuity.
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Affiliation(s)
- Stephen Tenney
- Georgetown University School of Medicine, Washington, DC, USA.
| | | | - David Wagner
- MedStar Georgetown University Hospital, Washington, DC, USA
| | - Mike Yuan Chen
- Georgetown University School of Medicine, Washington, DC, USA
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Mathew NE, Kozak J, Jayasundera KT, Jain N, Prabhu SS. CRYSTALLINE RETINOPATHY IN A 6-YEAR-OLD BOY WITH HISTORY OF HIGH-DOSE TAMOXIFEN USE. Retin Cases Brief Rep 2023; 17:751-753. [PMID: 35383718 DOI: 10.1097/icb.0000000000001280] [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: 06/14/2023]
Abstract
BACKGROUND/PURPOSE To report a case of crystalline retinopathy following high-dose tamoxifen use in a pediatric patient. METHODS Observational case report. RESULTS A 6-year-old boy with history of more than 80-g cumulative tamoxifen use over 25 months for the treatment of atypical teratoid/rhabdoid tumor of the posterior fossa presented with a 4-month history of blurred vision. Fundus examination demonstrated multiple superficial foveal refractile opacities in each eye, and spectral optical coherence tomography revealed numerous punctate hyperreflective deposits located within the inner retina. These findings were suggestive of tamoxifen retinopathy. CONCLUSION To our knowledge, this is the first report of multimodal retinal imaging of tamoxifen retinopathy in a pediatric patient. Given the risk of permanent vision loss, ophthalmic baseline screening and monitoring should be considered for children receiving tamoxifen.
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Affiliation(s)
- Namita E Mathew
- Emory University School of Medicine, Emory University, Atlanta, Georgia
| | - Jennifer Kozak
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan
| | | | - Nieraj Jain
- Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia; and
| | - Shreya S Prabhu
- Department of Ophthalmology, University at Buffalo Jacobs School of Medicine, Buffalo, New York
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Bazvand F, Mahdizad Z, Mohammadi N, Shahi F, Mirghorbani M, Riazi-Esfahani H, Modjtahedi BS. Tamoxifen retinopathy. Surv Ophthalmol 2023:S0039-6257(23)00038-3. [PMID: 36781026 DOI: 10.1016/j.survophthal.2023.02.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 02/03/2023] [Accepted: 02/06/2023] [Indexed: 02/13/2023]
Abstract
Tamoxifen (TAM) is a selective estrogen receptor modulator that is used in the treatment of breast cancer. As there are estrogen receptors in the retina, retinal pigment epithelium, and choroid, these tissues may also be affected by TAM. We describe the reported effects of TAM on the retina and choroid. Medical databases were searched using relevant keywords and the results were extracted and pooled. The incidence of retinal/choroidal toxicity ranged from 0.9% to 12%. There was a wide range for the time of exposure before the development of TAM retinopathy (3 weeks to 13 years). While functional measurements may be appropriate for assessment of TAM retinopathy, they have not been effective for screening patients. There is no generally accepted screening modality, but serial funduscopy and optical coherence tomography imaging seem to be the most reasonable approach for detecting early TAM-induced retinal toxicity.
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Affiliation(s)
- Fatemeh Bazvand
- Department of Ophthalmology, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Zahra Mahdizad
- Department of Ophthalmology, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Nader Mohammadi
- Department of Ophthalmology, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Farhad Shahi
- Department of Hematology and Medical Oncology, Cancer Research Center, Cancer Institute, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran
| | - Masoud Mirghorbani
- Department of Ophthalmology, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
| | - Hamid Riazi-Esfahani
- Department of Ophthalmology, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Bobeck S Modjtahedi
- Department of Research and Evaluation, Southern California Permanente Medical Group, Pasadena, CA, USA; Department of Clinical Science, Kaiser Permanente Bernard J. Tyson School of Medicine, Pasadena, CA, USA; Eye Monitoring Center, Kaiser Permanente Southern California, Baldwin Park, CA, USA
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5
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Lu J, Huang Y, Ye Q, Shang F, Ming M, Xu H, Li Z. Low-dose oral hydroxychloroquine led to impaired vision in a child with renal failure: Case report and literature review. Medicine (Baltimore) 2021; 100:e24919. [PMID: 33725851 PMCID: PMC7969273 DOI: 10.1097/md.0000000000024919] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 02/04/2021] [Indexed: 01/05/2023] Open
Abstract
INTRODUCTION Hydroxychloroquine (HCQ) has received much attention in the treatment of coronavirus disease 2019 recently. However, it can cause irreversible vision loss. Few cases have been reported in pediatric patient with HCQ-related adverse reactions. Appropriate administration and early disease recognition are important for reducing the adverse drug reactions of HCQ. PATIENT CONCERNS We report a case of a 14-year-old Chinese girl who sought treatment for rapidly decreasing vision in the left eye over 3 days. The simulation results of the population pharmacokinetic model of HCQ revealed that the plasma concentration of HCQ abnormally increased before the visual acuity of the eye decreased. DIAGNOSIS She was diagnosed as HCQ related drug adverse reaction. INTERVENTIONS The daily dose of HCQ for this patient was adjusted from 100 mg/d to 50 mg/d. OUTCOMES Follow-up for 6 months showed no more vision loss recurrence. However, the existing decreased visual acuity of the eye did not recover either. CONCLUSION Although decreased visual acuity is an infrequent symptom, ophthalmologists should be aware of the possibility of HCQ concentration enrichment and consider minimizing HCQ use when a child with renal hypofunction seeks treatment for shortsightedness.
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Affiliation(s)
- Jinmiao Lu
- Department of Clinical Pharmacy, Children's Hospital of Fudan University, Shanghai
| | - Yidie Huang
- Department of Clinical Pharmacy, Children's Hospital of Fudan University, Shanghai
| | - Qiaofeng Ye
- Department of Clinical Pharmacy, Children's Hospital of Fudan University, Shanghai
| | - Feineng Shang
- Department of Pharmacy, Dehong People's Hospital, Yunnan
| | - Mei Ming
- Department of ophthalmology, Huangshi Central Hospital, Affiliated Hospital of Hubei Polytechnic University, Huangshi
| | - Hong Xu
- Department of Nephrology, Children's Hospital of Fudan University, Shanghai, China
| | - Zhiping Li
- Department of Clinical Pharmacy, Children's Hospital of Fudan University, Shanghai
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Zinc and Autophagy in Age-Related Macular Degeneration. Int J Mol Sci 2020; 21:ijms21144994. [PMID: 32679798 PMCID: PMC7404247 DOI: 10.3390/ijms21144994] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 07/13/2020] [Accepted: 07/13/2020] [Indexed: 02/06/2023] Open
Abstract
Zinc supplementation is reported to slow down the progression of age-related macular degeneration (AMD), but there is no general consensus on the beneficiary effect on zinc in AMD. As zinc can stimulate autophagy that is declined in AMD, it is rational to assume that it can slow down its progression. As melanosomes are the main reservoir of zinc in the retina, zinc may decrease the number of lipofuscin granules that are substrates for autophagy. The triad zinc–autophagy–AMD could explain some controversies associated with population studies on zinc supplementation in AMD as the effect of zinc on AMD may be modulated by genetic background. This aspect was not determined in many studies regarding zinc in AMD. Zinc deficiency induces several events associated with AMD pathogenesis, including increased oxidative stress, lipid peroxidation and the resulting lipofuscinogenesis. The latter requires autophagy, which is impaired. This is a vicious cycle-like reaction that may contribute to AMD progression. Promising results with zinc deficiency and supplementation in AMD patients and animal models, as well as emerging evidence of the importance of autophagy in AMD, are the rationale for future research on the role of autophagy in the role of zinc supplementation in AMD.
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Oliveira KRHM, Kauffmann N, Leão LKR, Passos ACF, Rocha FAF, Herculano AM, do Nascimento JLM. Cerebral malaria induces electrophysiological and neurochemical impairment in mice retinal tissue: possible effect on glutathione and glutamatergic system. Malar J 2017; 16:440. [PMID: 29096633 PMCID: PMC5668953 DOI: 10.1186/s12936-017-2083-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 10/23/2017] [Indexed: 01/28/2023] Open
Abstract
Background Cerebral malaria (CM) is a severe complication resulting from Plasmodium falciparum infection. This condition has usually been associated with cognitive, behavioural and motor dysfunctions, being the retinopathy the most serious consequence resulting from the disease. The pathophysiological mechanisms underlying this complication remain incompletely understood. Several experimental models of CM have already been developed in order to clarify those mechanisms related to this syndrome. In this context, the present work has been performed to investigate which possible electrophysiological and neurochemistry alterations could be involved in the CM pathology. Methods Experimental CM was induced in Plasmodium berghei-infected male and female C57Bl/6 mice. The survival and neurological symptoms of CM were registered. Brains and retina were assayed for TNF levels and NOS2 expression. Electroretinography measurements were recorded to assessed a- and b-wave amplitudes and neurochemicals changes were evaluated by determination of glutamate and glutathione levels by HPLC. Results Susceptible C57Bl/6 mice infected with ≈ 106 parasitized red blood cells (P. berghei ANKA strain), showed a low parasitaemia, with evident clinical signs as: respiratory failure, ataxia, hemiplegia, and coma followed by animal death. In parallel to the clinical characterization of CM, the retinal electrophysiological analysis showed an intense decrease of a- and-b-wave amplitude associated to cone photoreceptor response only at the 7 days post-infection. Neurochemical results demonstrated that the disease led to a decrease in the glutathione levels with 2 days post inoculation. It was also demonstrated that the increase in the glutathione levels during the infection was followed by the increase in the 3H-glutamate uptake rate (4 and 7 days post-infection), suggesting that CM condition causes an up-regulation of the transporters systems. Furthermore, these findings also highlighted that the electrophysiological and neurochemical alterations occurs in a manner independent on the establishment of an inflammatory response, once tumour necrosis factor levels and inducible nitric oxide synthase expression were altered only in the cerebral tissue but not in the retina. Conclusions In summary, these findings indicate for the first time that CM induces neurochemical and electrophysiological impairment in the mice retinal tissue, in a TNF-independent manner.
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Affiliation(s)
- Karen R H M Oliveira
- Laboratório de Neurofarmacologia Experimental, Instituto de Ciências Biológicas, Universidade Federal do Pará, R. Augusto Corrêa, 01, Belém, PA, 66075-110, Brazil.
| | - Nayara Kauffmann
- Laboratório de Neurofarmacologia Experimental, Instituto de Ciências Biológicas, Universidade Federal do Pará, R. Augusto Corrêa, 01, Belém, PA, 66075-110, Brazil
| | - Luana K R Leão
- Laboratório de Neurofarmacologia Experimental, Instituto de Ciências Biológicas, Universidade Federal do Pará, R. Augusto Corrêa, 01, Belém, PA, 66075-110, Brazil
| | - Adelaide C F Passos
- Laboratório de Neurofarmacologia Experimental, Instituto de Ciências Biológicas, Universidade Federal do Pará, R. Augusto Corrêa, 01, Belém, PA, 66075-110, Brazil
| | - Fernando A F Rocha
- Laboratório de Neurofisiologia Eduardo Oswaldo Cruz, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil
| | - Anderson M Herculano
- Laboratório de Neurofarmacologia Experimental, Instituto de Ciências Biológicas, Universidade Federal do Pará, R. Augusto Corrêa, 01, Belém, PA, 66075-110, Brazil
| | - José L M do Nascimento
- Laboratório de Neuroquímica Molecular e Celular Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil
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Zhao J, Kim HJ, Sparrow JR. Multimodal Fundus Imaging of Sodium Iodate-Treated Mice Informs RPE Susceptibility and Origins of Increased Fundus Autofluorescence. Invest Ophthalmol Vis Sci 2017; 58:2152-2159. [PMID: 28395299 PMCID: PMC5389744 DOI: 10.1167/iovs.17-21557] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Purpose By multimodal imaging, and the use of mouse and in vitro models, we have addressed changes in fundus autofluorescence (488 and 790 nm) and observed interactions between the photooxidative stress imposed by RPE bisretinoid lipofuscin and the oxidative impact of systemic sodium iodate (NaIO3). Methods Abca4−/−, wild-type, and Rpe65rd12 mice were given systemic injections of NaIO3 (30 mg/kg). Analysis included noninvasive imaging of fundus autofluorescence (short-wavelength [SW-AF]; near-infrared excitation [NIR-AF]), quantitative fundus AF (qAF; 488 nm); light microscopy, RPE flat-mounts and measurements of outer nuclear layer (ONL) thickness. NaIO3 also was studied by using in vitro assays. Results In SW-AF and NIR-AF images, fundus mottling was visible 3 and 7 days after NaIO3 injection with changes being more pronounced in Abca4−/− mice that are characterized by an abundance of RPE bisretinoid lipofuscin. In Abca4−/− mice, qAF was elevated 3 and 7 days after NaIO3 administration. In light micrographs and RPE flat-mounts stained to reveal tight junctions (ZO-1) and nuclei, the RPE monolayer was disorganized, and clumping and loss of RPE was visible. ONL thinning was most pronounced in Abca4−/− mice. Treatment of ARPE-19 cells with NaIO3 together with the photooxidation of the bisretinoid A2E by exposure to 430-nm light produced an additive effect whereby loss of cell viability was greater than with either perturbation alone. Conclusions Elevations in SW-AF intensity can occur due to photoreceptor cell dysfunction as induced secondarily by NaIO3. Photooxidative stress associated with RPE cell bisretinoid lipofuscin may confer increased susceptibility to the oxidant NaIO3.
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Affiliation(s)
- Jin Zhao
- Department of Ophthalmology, Columbia University Medical Center, New York, New York, United States
| | - Hye Jin Kim
- Department of Ophthalmology, Columbia University Medical Center, New York, New York, United States
| | - Janet R Sparrow
- Department of Ophthalmology, Columbia University Medical Center, New York, New York, United States 2Pathology and Cell Biology, Columbia University Medical Center, New York, New York, United States
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Chen X, Wang S, Xu H, Pereira JD, Hatzistergos KE, Saur D, Seidler B, Hare JM, Perrella MA, Yin ZQ, Liu X. Evidence for a retinal progenitor cell in the postnatal and adult mouse. Stem Cell Res 2017; 23:20-32. [PMID: 28672156 DOI: 10.1016/j.scr.2017.06.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 06/16/2017] [Accepted: 06/19/2017] [Indexed: 12/22/2022] Open
Abstract
Progress in cell therapy for retinal disorders has been challenging. Recognized retinal progenitors are a heterogeneous population of cells that lack surface markers for the isolation of live cells for clinical implementation. In the present application, our objective was to use the stem cell factor receptor c-Kit (CD117), a surface marker, to isolate and evaluate a distinct progenitor cell population from retinas of postnatal and adult mice. Here we report that, by combining traditional methods with fate mapping, we have identified a c-Kit-positive (c-Kit+) retinal progenitor cell (RPC) that is self-renewing and clonogenic in vitro, and capable of generating many cell types in vitro and in vivo. Based on cell lineage tracing, significant subpopulations of photoreceptors in the outer nuclear layer and bipolar, horizontal, amacrine and Müller cells in the inner nuclear layer are the progeny of c-Kit+ cells in vivo. The RPC progeny contributes to retinal neurons and glial cells, which are responsible for the conversion of light into visual signals. The ability to isolate and expand in vitro live c-Kit+ RPCs makes them a future therapeutic option for retinal diseases.
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Affiliation(s)
- Xi Chen
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing, China; Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Shaojun Wang
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing, China; Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Haiwei Xu
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing, China
| | - Joao D Pereira
- Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; Department of Anesthesia, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Dieter Saur
- Medicine II, Technische Universitaet Muenchen, Munich, Germany; German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Barbara Seidler
- Medicine II, Technische Universitaet Muenchen, Munich, Germany; German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Joshua M Hare
- Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Mark A Perrella
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; Department of Pediatric Newborn Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Zheng Qin Yin
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing, China
| | - Xiaoli Liu
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; Department of Pediatric Newborn Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
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Tamoxifen Provides Structural and Functional Rescue in Murine Models of Photoreceptor Degeneration. J Neurosci 2017; 37:3294-3310. [PMID: 28235894 DOI: 10.1523/jneurosci.2717-16.2017] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Revised: 02/05/2017] [Accepted: 02/08/2017] [Indexed: 12/19/2022] Open
Abstract
Photoreceptor degeneration is a cause of irreversible vision loss in incurable blinding retinal diseases including retinitis pigmentosa (RP) and atrophic age-related macular degeneration. We found in two separate mouse models of photoreceptor degeneration that tamoxifen, a selective estrogen receptor modulator and a drug previously linked with retinal toxicity, paradoxically provided potent neuroprotective effects. In a light-induced degeneration model, tamoxifen prevented onset of photoreceptor apoptosis and atrophy and maintained near-normal levels of electroretinographic responses. Rescue effects were correlated with decreased microglial activation and inflammatory cytokine production in the retina in vivo and a reduction of microglia-mediated toxicity to photoreceptors in vitro, indicating a microglia-mediated mechanism of rescue. Tamoxifen also rescued degeneration in a genetic (Pde6brd10) model of RP, significantly improving retinal structure, electrophysiological responses, and visual behavior. These prominent neuroprotective effects warrant the consideration of tamoxifen as a drug suitable for being repurposed to treat photoreceptor degenerative disease.SIGNIFICANCE STATEMENT Photoreceptor degeneration is a cause of irreversible blindness in a number of retinal diseases such as retinitis pigmentosa (RP) and atrophic age-related macular degeneration. Tamoxifen, a selective estrogen receptor modulator approved for the treatment of breast cancer and previously linked to a low incidence of retinal toxicity, was unexpectedly found to exert marked protective effects against photoreceptor degeneration. Structural and functional protective effects were found for an acute model of light-induced photoreceptor injury and for a genetic model for RP. The mechanism of protection involved the modulation of microglial activation and the production of inflammatory cytokines, highlighting the role of inflammatory mechanisms in photoreceptor degeneration. Tamoxifen may be suitable for clinical study as a potential treatment for diseases involving photoreceptor degeneration.
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Bourgeois N, Chavant F, Lafay-Chebassier C, Leveziel N, Pérault-Pochat MC. Atteintes rétiniennes iatrogènes : étude cas/non cas dans la banque nationale de pharmacovigilance. Therapie 2016; 71:365-74. [DOI: 10.1016/j.therap.2016.02.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 02/12/2016] [Indexed: 01/19/2023]
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Theoretical elucidation of the metabolic mechanisms of phenothiazine neuroleptic chlorpromazine catalyzed by cytochrome P450 isoenzyme 1A2. Theor Chem Acc 2016. [DOI: 10.1007/s00214-016-1943-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Otreba M, Wrześniok D, Beberok A, Rok J, Buszman E. Melanogenesis and antioxidant defense system in normal human melanocytes cultured in the presence of chlorpromazine. Toxicol In Vitro 2015; 29:221-7. [PMID: 25449126 DOI: 10.1016/j.tiv.2014.10.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 10/14/2014] [Accepted: 10/17/2014] [Indexed: 11/17/2022]
Abstract
Chlorpromazine is used in the treatment of schizophrenia and psychotic disorders and belongs to phenothiazine class of neuroleptic drugs. It shows severe side effects such as extrapyramidal symptoms as well as ocular and skin disorders, but the mechanism is still not fully established. The aim of this study was to examine the effect of chlorpromazine on cell viability, melanogenesis and antioxidant defense system in normal human melanocytes. It has been demonstrated that chlorpromazine induces concentration dependent loss in cell viability. The value of EC(50) was calculated to be 2.53 μM. Chlorpromazine in lower concentrations (0.0001, 0.001 and 0.01 μM) increased the melanin and microphthalmia-associated transcription factor (MITF) content and tyrosinase activity, while changes of antioxidant enzymes activity were not observed. It suggests that long-term chlorpromazine therapy, even with low drug doses, may lead to hyperpigmentation disorders in skin and/or eye. The use of the analyzed drug in higher concentrations (0.1 and 1.0 μM) caused significant alterations of antioxidant enzymes activity in normal melanocytes, what may explain a potential role of chlorpromazine in the depletion of cellular antioxidant status leading to other adverse effects associated with the high-dose and/or long-term therapy.
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Affiliation(s)
- Michał Otreba
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Medical University of Silesia, Jagiellońska 4, PL 41-200 Sosnowiec, Poland
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Otręba M, Zdybel M, Pilawa B, Beberok A, Wrześniok D, Rok J, Buszman E. EPR spectroscopy of chlorpromazine-induced free radical formation in normal human melanocytes. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2015; 44:359-65. [PMID: 25981866 PMCID: PMC4464733 DOI: 10.1007/s00249-015-1029-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 03/27/2015] [Accepted: 04/29/2015] [Indexed: 11/26/2022]
Abstract
The purpose of this study was to estimate the effect of chlorpromazine on free radical concentration in HEMn-DP melanocytes using electron paramagnetic resonance (EPR) spectroscopy. It was found that chlorpromazine at concentrations of 1 × 10(-7) and 1 × 10(-6) M contributed to the formation of free radicals (g values ~2) in a dose-dependent manner. The increase in free radical formation was accompanied by an increase in cytotoxicity, as shown by a tetrazolium assay. Homogeneous broadening of EPR lines, slow spin-lattice relaxation processes, and strong dipolar interactions characterized all the tested cellular samples. The performed examination of free radical formation in cells exposed to different chlorpromazine concentrations confirmed the usefulness of electron paramagnetic resonance spectroscopy to determine the effect of a drug on free radical production in a cellular model system in vitro.
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Affiliation(s)
- Michał Otręba
- />Chair and Department of Pharmaceutical Chemistry, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Jagiellońska 4, 41-200 Sosnowiec, Poland
| | - Magdalena Zdybel
- />Chair and Department of Biophysics, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Jedności 8, 41-200 Sosnowiec, Poland
| | - Barbara Pilawa
- />Chair and Department of Biophysics, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Jedności 8, 41-200 Sosnowiec, Poland
| | - Artur Beberok
- />Chair and Department of Pharmaceutical Chemistry, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Jagiellońska 4, 41-200 Sosnowiec, Poland
| | - Dorota Wrześniok
- />Chair and Department of Pharmaceutical Chemistry, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Jagiellońska 4, 41-200 Sosnowiec, Poland
| | - Jakub Rok
- />Chair and Department of Pharmaceutical Chemistry, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Jagiellońska 4, 41-200 Sosnowiec, Poland
| | - Ewa Buszman
- />Chair and Department of Pharmaceutical Chemistry, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Jagiellońska 4, 41-200 Sosnowiec, Poland
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Abstract
The present study focused on potentially beneficial effects of agmatine on oxidative stress development in the liver during chlorpromazine treatment in rats. We wanted to examine the role of reactive oxygen species and efficiency of antioxidant protection through the determination of malondylaldehyde and total glutathione concentrations in rat liver homogenate, as well as plasma concentrations of malonylaldehyde and sulfhydryl groups after the treatment. Also, liver tissue sections were examined to follow histological changes. Chlorpromazine was applied intraperitoneally at a single dose of 38.7 mg/kg b.w. The second group was treated with both chlorpromazine (at a single dose of 38.7 mg/kg b.w.) and agmatine (at a single dose of 75 mg/kg b.w.). Agmatine was applied immediately after the chlorpromazine. The control group was treated with 0.9% saline solution in the same manner. Rats were sacrificed by decapitation 24 h after the treatment and biochemical and immunohistochemical examinations were performed. Analysis of data showed that treatment with agmatine significantly attenuated the oxidative stress indicators as evidenced by lowering malonylaldehyde concentrations in the liver and in plasma while not affecting liver concentrations of total glutathione and plasma concentration of sulfhydryl groups. Additionally, histological evaluation revealed the improvement of liver damage in this respect. The presented data indicated that intraperitoneally administered agmatine protects against chlorpromazine-induced liver disease in rats.
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Optical coherence tomography findings in hydroxychloroquine and chloroquine-associated maculopathy. Retin Cases Brief Rep 2014; 1:128-30. [PMID: 25390773 DOI: 10.1097/01.iae.0000226540.61840.d7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Vision loss and maculopathy associated with hydroxychloroquine and chloroquine use are infrequent but significant adverse effects. Bull's eye maculopathy related to these drugs, including peripheral and macular pigment changes, has been described; however, to our knowledge, optical coherence tomography (OCT) findings of the associated retinal pigment epithelium (RPE) atrophy have not yet been reported. METHODS Single case report. RESULTS A 48-year-old woman was treated with hydroxychloroquine (7.8 mg/[kg · d]) for 8 years followed by chloroquine (3.9 mg/[kg · d]) for 5 months for systemic lupus erythematosus. Fundus examinations for toxicity were conducted every 6 months. These medications were discontinued when the patient developed photopsias. Nine years after discontinuation, the patient further developed new scotomas and a bull's eye pattern RPE atrophy. The photographic and OCT findings of hydroxychloroquine- and chloroquine-associated maculopathy are presented along with guidelines on dosing and screening. CONCLUSION The ophthalmologist's awareness of dosing guidelines and communication with prescribing physicians are important in preventing ocular toxicities associated with hydroxychloroquine and chloroquine. Current guidelines suggest the following maximal dosages: hydroxychloroquine, 6.5 mg/(kg · d); and chloroquine, 3 mg/(kg · d). A patient weighing <135 lb should not receive >400 mg of hydroxychloroquine daily.
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Abstract
The 4-aminoquinolines are weak bases that are completely absorbed from the gastrointestinal tract, sequestered in peripheral tissues, metabolized in the liver to pharmacologically active by-products, and excreted via the kidneys and the feces. The parent drugs and metabolites are excreted with a half-life of elimination of approximately 40 days. However, slow release from sequestered stores of the drugs means that after discontinuation, they continue to be released into the plasma for years. Correct dosing is based on the ideal body weight of the patient, which depends on height. The 4AQs diminish autoimmunity without compromising immunity to infections.
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Affiliation(s)
- David J. Browning
- grid.490463.cCharlotte Eye Ear Nose & Throat Associates, Charlotte, NC USA
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Scholz RT, Sunness JS. Dark adaptation abnormalities and recovery in acute thioridazine toxicity. Retin Cases Brief Rep 2014; 8:45-49. [PMID: 25372207 DOI: 10.1097/icb.0000000000000000] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
PUPOSE To document acute thioridazine toxicity from the symptoms only, through the development of ophthalmoscopic signs and recovery of dark adaptation and electroretinogram responses. These findings support the thesis that visual loss is metabolic and reversible if diagnosed early. METHODS Case Report. RESULTS A case is presented of acute thioridazine toxicity with documentation of the development of symptoms before any ophthalmoscopic evidence of toxicity. This case uniquely shows the time course of dark adaptation, showing both delay in adaptation and elevated final threshold, it includes full electrophysiologic studies from within the first weeks of symptoms and regular follow-up demonstrating marked recovery of dark adaptation in terms of both delay and final threshold, a nearly normal electroretinography and normal color vision within 10 months. CONCLUSION Our findings give support to the thesis that functional visual disturbance is primarily metabolic and reversible if detected early in the course of toxicity.
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Affiliation(s)
- Richard T Scholz
- *Clinical Associates, Baltimore, Maryland; and †Department of Ophthalmology, Richard E. Hoover Low Vision Rehabilitation Services, Greater Baltimore Medical Center, Baltimore, Maryland
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19
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Bernasinska J, Duchnowicz P, Koter-Michalak M, Koceva-Chyla A. Effect of safeners on damage of human erythrocytes treated with chloroacetamide herbicides. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2013; 36:368-377. [PMID: 23732483 DOI: 10.1016/j.etap.2013.04.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 03/28/2013] [Accepted: 04/21/2013] [Indexed: 05/18/2023]
Abstract
Chloroacetamides are used as pre-emergent substances for growth control of annual grasses and weeds. Since they can be harmful for crop plants, protective compounds (safeners) are used along with herbicides. So far, their effects on human blood cells have not been evaluated, and this study is the very first one devoted to this subject. We examined the harmful effects of chloroacetamides, their metabolites and safeners, used alone or in combination with herbicides, on human erythrocytes measuring the extent of hemolysis, lipid peroxidation and catalase activity. Higher impact of herbicides than their metabolites on all of the investigated parameters was found. Safeners alone did not produce any damage to erythrocytes and did not elicit any changes in oxidative stress parameters. Combination of safener with herbicide did not attenuate hemolysis of erythrocytes compared to the herbicide alone. Safeners reduced lipid peroxidation induced by herbicides, which suggest the role of safeners as antioxidants.
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Affiliation(s)
- Joanna Bernasinska
- Department of Thermobiology, Institute of Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, 141/143 Pomorska St., 90-237 Lodz, Poland.
| | - Piotr Duchnowicz
- Department of Environmental Pollution Biophysics, Institute of Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, 141/143 Pomorska St., 90-237 Lodz, Poland
| | - Maria Koter-Michalak
- Department of Environmental Pollution Biophysics, Institute of Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, 141/143 Pomorska St., 90-237 Lodz, Poland
| | - Aneta Koceva-Chyla
- Department of Thermobiology, Institute of Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, 141/143 Pomorska St., 90-237 Lodz, Poland
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20
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Effects of three different fibrates on intrahepatic cholestasis experimentally induced in rats. PPAR Res 2013; 2013:781348. [PMID: 23997763 PMCID: PMC3753769 DOI: 10.1155/2013/781348] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 06/16/2013] [Accepted: 07/10/2013] [Indexed: 02/06/2023] Open
Abstract
Background. Activation of PPAR α modulates cholesterol metabolism and suppresses bile acid synthesis. This study aims to evaluate the effect of PPAR α agonists, fenofibrate, bezafibrate, and gemfibrozil, on acute cholestasis induced by ethinylestradiol (EE) plus chlorpromazine (CPZ) in rats. Method. 100 male albino rats (150-200 gm) were divided randomly into 10 equal groups. Control group received 1% methylcellulose vehicle; disease group received CPZ plus EE for 5 consecutive days; four groups received either ursodeoxycholic acid, fenofibrate, bezafibrate, or gemfibrozil for 7 days; 2 days before EE + CPZ, three other groups received one of the three fibrates after GW6471, a selective PPAR α antagonist in addition to EE + CPZ. The final group received GW6471 alone. Results. The three fibrates showed marked reduction (P < 0.05) in serum levels of ALP, GGT, ALT, AST, total bile acids, bilirubin, TNF α , and IL-1 β and in hepatic malondialdehyde level as well as a significant increase in bile flow rate (P < 0.05) in addition to improvements in histopathological parameters compared to diseased group. In groups which received GW6471, these effects were completely abolished with fenofibrate and partially blocked with bezafibrate and gemfibrozil. Conclusion. Short-term administration of fibrates to EE/CPZ-induced intrahepatic cholestatic rats exerted beneficial effects on hepatocellular damage and apoptosis. Fenofibrate anticholestatic effect was solely PPAR α dependent while other mechanisms played part in bezafibrate and gemfibrozil actions.
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21
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Georgalas I, Paraskevopoulos T, Papaconstaninou D, Brouzas D, Koutsandrea C. Large bilateral foveal cysts in the inner retina of a patient treated with tamoxifen, diagnosed with Fourier-domain optical coherence tomography. Clin Ophthalmol 2013; 7:707-9. [PMID: 23630411 PMCID: PMC3626412 DOI: 10.2147/opth.s38951] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Purpose To report a case of a patient receiving tamoxifen with visual deterioration and describe the unusual optical coherence tomography (OCT) findings. Method Observational case report. Results A 55-year-old female patient was referred to our department complaining of gradual visual deterioration in both eyes. Medical history was unremarkable apart from breast cancer for which she had received tamoxifen for 10 years (mean dosage 20 mg/day). Best corrected visual acuity was 20/400 in her right eye and 20/40 in her left eye. Fundoscopy in both eyes was without any obvious signs of maculopathy. However, Fourier-domain OCT demonstrated bilateral extensive areas of disruption in inner retinal layers without any signs of crystalline retinopathy. Six months after the cessation of tamoxifen, the situation remains unchanged. Conclusion Patients receiving tamoxifen should be monitored with high-resolution OCT for fundoscopically invisible changes in the inner retinal layers, the progression of which may seriously affect the patient’s vision and subsequently their quality of life.
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Affiliation(s)
- Ilias Georgalas
- Department of Ophthalmology, "G Gennimatas" Hospital of Athens, NHS, University of Athens, Athens, Greece
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22
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Shi R, Zhang Y, Shi Y, Shi S, Jiang L. Inhibition of peroxisomal β-oxidation by thioridazine increases the amount of VLCFAs and Aβ generation in the rat brain. Neurosci Lett 2012; 528:6-10. [PMID: 22985512 DOI: 10.1016/j.neulet.2012.08.086] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 08/04/2012] [Accepted: 08/30/2012] [Indexed: 12/21/2022]
Abstract
Alzheimer's disease (AD) is characterized by the accumulation of the β-amyloid peptide (Aβ), which is generated from sequential cleavages of the amyloid precursor protein (APP) by β-secretase (BACE1) and γ-secretase. Fatty acid alterations in AD brains have recently received substantial attention. Because increased very long chain fatty acid (VLCFA) levels in AD brains imply that peroxisomal β-oxidation dysfunction may be associated with AD pathogenesis, we investigated the effects of impaired peroxisomal β-oxidation on Aβ generation in vivo and in vitro using thioridazine, a selective peroxisomal β-oxidation inhibitor. Under the experimental conditions, thioridazine caused VLCFA accumulation and increases in Aβ(40) content, APP immunoreactivity and APP(751+770) mRNA expressions in the rat cerebral cortex. A correlation analysis showed that the Aβ(40) levels were positively correlated with the cortex C(24:0) and C(26:0) levels. Additionally, the primary cerebral cortex neurons treated with this compound showed increases in APP(751+770) mRNA, APP protein, BACE1 mRNA and protein, and secreted Aβ40 levels. This work supports an emerging viewpoint that impaired peroxisomal function may play an important role in the progression of AD pathology.
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Affiliation(s)
- Ruling Shi
- Department of Biochemistry and Molecular Biology, Hebei Medical University, Shijiazhuang 050017, China
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23
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Gokulgandhi MR, Vadlapudi AD, Mitra AK. Ocular toxicity from systemically administered xenobiotics. Expert Opin Drug Metab Toxicol 2012; 8:1277-91. [PMID: 22803583 DOI: 10.1517/17425255.2012.708337] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION The eye is considered as the most privileged organ because of the blood-ocular barrier that acts as a barrier to systemically administered xenobiotics. However, there has been a significant increase in the number of reports on systemic drug-induced ocular complications. If such complications are left untreated, then it may cause permanent damage to vision. Hence, knowledge of most recent updates on ever-increasing reports of such toxicities has become imperative to develop better therapy while minimizing toxicities. AREAS COVERED The article is mainly divided into anterior and posterior segment manifestations caused by systemically administered drugs. The anterior segment is further elaborated on corneal complications where as the posterior segment is focused on optic nerve, retinal and vitreous complications. Furthermore, this article includes recent updates on acute and chronic ocular predicaments, in addition to discussing various associated symptoms caused by drugs. EXPERT OPINION Direct correlation of ocular toxicities due to systemic drug therapy is evident from current literature. Therefore, it is necessary to have detailed documentation of these complications to improve understanding and predict toxicities. We made an attempt to ensure that the reader is aware of the characteristic ocular complications, the potential for irreversible drug toxicity and indications for cessation.
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Affiliation(s)
- Mitan R Gokulgandhi
- University of Missouri-Kansas City, School of Pharmacy, Division of Pharmaceutical Sciences, HSB 5258, 2464 Charlotte St, Kansas City, MO 64108, USA
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24
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Uzar E, Ozay R, Evliyaoglu O, Aktas A, Ulkay MB, Uyar ME, Ersoy A, Burakgazi AZ, Turkay C, Ilhan A. Hydroxycloroquine-induced oxidative stress on sciatic nerve and muscle tissue of rats. Hum Exp Toxicol 2012; 31:1066-73. [DOI: 10.1177/0960327111433183] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- E Uzar
- Department of Neurology, School of Medicine, Dicle University, Diyarbakır, Turkey
| | - R Ozay
- Department of Neurosurgery, Etlik Ihtisas Research and Educational Hospital, Ankara, Turkey
| | - O Evliyaoglu
- Department of Biochemistry, School of Medicine, Dicle University, Diyarbakır, Turkey
| | - A Aktas
- Faculty of Veterinary Medicine, Department of Histology and Embryology, Istanbul University, Istanbul, Turkey
| | - MB Ulkay
- Faculty of Veterinary Medicine, Department of Histology and Embryology, Istanbul University, Istanbul, Turkey
| | - ME Uyar
- Department of Internal Medicine, School of Medicine, Fatih University, Ankara, Turkey
| | - A Ersoy
- Department of Neurology, School of Medicine, Fatih University, Ankara, Turkey
| | - AZ Burakgazi
- Neuroscience Section, Virginia Tech Carilion School of Medicine, Roanoke, USA
| | - C Turkay
- Department of Internal Medicine, School of Medicine, Fatih University, Ankara, Turkey
| | - A Ilhan
- Department of Neurology, School of Medicine, Fatih University, Ankara, Turkey
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Abstract
PURPOSE OF REVIEW Various medications can modify the physiology of retinal and cochlear neurons and lead to major, sometime permanent, sensory loss. A better knowledge of pathogenic mechanisms and the establishment of relevant monitoring protocols are necessary to prevent permanent sensory impairment. In this article, we review main systemic medications associated with direct neuronal toxicity on the retina and cochlea, their putative pathogenic mechanisms, when identified, as well as current recommendations, when available, for monitoring protocols. RECENT FINDINGS Pathogenic mechanisms and cellular target of retinotoxic drugs are often not well characterized but a better knowledge of the course of visual defect has recently helped in defining more relevant monitoring protocols especially for antimalarials and vigabatrin. Mechanisms of ototoxicity have recently been better defined, from inner ear entry with the use of fluorescent tracers to evidence for the role of oxidative stress and program cell death pathways. SUMMARY Experimental and clinical studies have elucidated some of the pathogenic mechanisms, courses and risk factors of retinal toxicity and ototoxicity, which have led to establishment of relevant monitoring protocols. Further studies are, however, warranted to better understand cellular pathways leading to degeneration. These would help to build more efficient preventive intervention and may also contribute to understanding of other degenerative processes such as genetic disorders.
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Ronzani G, Giaretta R, Morello M. Evaluation of oxidative stress and antioxidative action of green tea catechins in patients treated with tamoxifen: a randomized open-label, crossover study. MEDITERRANEAN JOURNAL OF NUTRITION AND METABOLISM 2011. [DOI: 10.1007/s12349-010-0020-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Caramoy A, Scholz P, Fauser S, Kirchhof B. Imaging tamoxifen retinopathy using spectral-domain optical coherence tomography. GMS OPHTHALMOLOGY CASES 2011; 1:Doc07. [PMID: 27625929 PMCID: PMC5015609 DOI: 10.3205/oc000007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A case of tamoxifen retinopathy examined with spectral-domain optical coherence tomography (SD-OCT) is presented. The typical refractile deposits are located between ganglion cell layer and inner plexiform layer in SD-OCT. A defect on the outer retinal layer with disruption of the photoreceptor layer with sharp edges is seen. The still attached posterior hyaloids gives evidence of other pathomechanism involved in the outer retinal defect than that of macular hole, as suggested in the literature.
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Affiliation(s)
- Albert Caramoy
- University of Cologne, Center of Ophthalmology, Department of Vitreo-Retinal Surgery, Cologne, Germany
| | - Paula Scholz
- University of Cologne, Center of Ophthalmology, Department of Vitreo-Retinal Surgery, Cologne, Germany
| | - Sascha Fauser
- University of Cologne, Center of Ophthalmology, Department of Vitreo-Retinal Surgery, Cologne, Germany
| | - Bernd Kirchhof
- University of Cologne, Center of Ophthalmology, Department of Vitreo-Retinal Surgery, Cologne, Germany
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28
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Feng J, Sun J, Wang MZ, Zhang Z, Kim ST, Zhu Y, Sun J, Xu J. Compilation of a comprehensive gene panel for systematic assessment of genes that govern an individual’s drug responses. Pharmacogenomics 2010; 11:1403-25. [DOI: 10.2217/pgs.10.99] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Aims: Polymorphisms of genes involved in the pharmacokinetic and pharmacodynamic processes underlie the divergent drug responses among individuals. Despite some successes in identifying these polymorphisms, the candidate gene approach suffers from insufficient gene coverage whereas the genome-wide association approach is limited by less than ideal coverage of SNPs in some important genes. To expand the potential of the candidate approach, we aim to delineate a comprehensive network of drug-response genes for in-depth genetic studies. Materials & methods: Pharmacologically important genes were extracted from various sources including literatures and web resources. These genes, along with their homologs and regulatory miRNAs, were organized based on their pharmacological functions and weighted by literature evidence and confidence levels. Their coverage was evaluated by analyzing three commercial SNP chips commonly used for genome-wide association studies: Affymetrix SNP array 6.0, Illumina HumanHap1M and Illumina Omni. Results: A panel of drug-response genes was constructed, which contains 923 pharmacokinetic genes, 703 pharmacodynamic genes and 720 miRNAs. There are only 16.7% of these genes whose all known SNPs can be directly or indirectly (r2 > 0.8) captured by the SNP chips with coverage of more than 80%. This is possibly because these SNPs chips have notably poor performance over rare SNPs and miRNA genes. Conclusion: We have compiled a panel of candidate genes that may be pharmacologically important. Using this knowledgebase, we are able to systematically evaluate genes and their variants that govern an individual’s response to a given pharmaceutical therapy. This approach can serve as a necessary complement to genome-wide associations.
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Affiliation(s)
- Junjie Feng
- Center for Cancer Genomics, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Jielin Sun
- Center for Cancer Genomics, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Michael Zhuo Wang
- Division of Pharmacotherapy & Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, NC, USA
| | - Zheng Zhang
- Center for Cancer Genomics, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Seong-Tae Kim
- Center for Cancer Genomics, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Yi Zhu
- Center for Cancer Genomics, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Jishan Sun
- Center for Cancer Genomics, Wake Forest University School of Medicine, Winston-Salem, NC, USA
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Redfern WS, Storey S, Tse K, Hussain Q, Maung KP, Valentin JP, Ahmed G, Bigley A, Heathcote D, McKay JS. Evaluation of a convenient method of assessing rodent visual function in safety pharmacology studies: effects of sodium iodate on visual acuity and retinal morphology in albino and pigmented rats and mice. J Pharmacol Toxicol Methods 2010; 63:102-14. [PMID: 20619348 DOI: 10.1016/j.vascn.2010.06.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2009] [Revised: 06/04/2010] [Accepted: 06/29/2010] [Indexed: 11/13/2022]
Abstract
INTRODUCTION We have evaluated the ability of a semi-automated, optomotor reflex method to assess drug-induced visual dysfunction, in albino and pigmented rats and mice. METHODS Male Han Wistar (HW) and Long Evans (LE) rats and mice (CD-1 and C57BL/6) were tested in a chamber formed by 4 computer monitors displaying a rotating vertical grating, to elicit head-tracking movements. The highest visible grating frequency was taken as the threshold of visual acuity, in cycles per degree (c/d). Animals received an intravenous infusion of either sodium iodate (50mg/kg) or 0.9% w/v NaCl (aq). They were tested 2h later, then re-tested daily for a further 3 days. The time course of the effect was assessed in HW rats over a 6-week period, including electron microscopy, and immunohistochemical analysis of markers of injury and repair in the retina. RESULTS Baseline visual acuities for HW and LE rats were 0.355 ± 0.007 and 0.530 ± 0.004 c/d, respectively, and 0.296 ± 0.003 c/d and 0.370 ± 0.001 c/d for CD-1 and C57BL/6 mice, respectively (n=10 for each). In HW rats there was a dramatic loss of visual acuity 2h after administration of sodium iodate (0.021 ± 0.021 c/d; P<0.001). Less dramatic decreases in visual acuity were seen in LE rats and in the two mouse strains. In HW rats, visual acuity was restored after 4 weeks. This paralleled the histopathological recovery of the peripheral retina, whereas the central retina did not recover. DISCUSSION The method proved to be very convenient, and the stability of visual acuity in vehicle control rats over a 6-week period also demonstrated its suitability for inclusion in long-term toxicity studies. Both albino and pigmented mice and rats are suitable for assessment of retinotoxicity using this method, but albino rats are the most sensitive to sodium iodate.
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Affiliation(s)
- William S Redfern
- Safety Pharmacology Departmen, Safety Assessment UK, AstraZeneca R&D, Alderley Park, Cheshire SK10 4TG, United Kingdom.
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Abstract
Glutathione and the related enzymes belong to the defence system protecting the eye against chemical and oxidative stress. This review focuses on GSH and two key enzymes, glutathione reductase and glucose-6-phosphate dehydrogenase in lens, cornea, and retina. Lens contains a high concentration of reduced glutathione, which maintains the thiol groups in the reduced form. These contribute to lens complete transparency as well as to the transparent and refractive properties of the mammalian cornea, which are essential for proper image formation on the retina. In cornea, gluthatione also plays an important role in maintaining normal hydration level, and in protecting cellular membrane integrity. In retina, glutathione is distributed in the different types of retinal cells. Intracellular enzyme, glutathione reductase, involved in reducing the oxidized glutathione has been found at highest activity in human and primate lenses, as compared to other species. Besides the enzymes directly involved in maintaining the normal redox status of the cell, glucose-6-phosphate dehydrogenase which catalyzes the first reaction of the pentose phosphate pathway, plays a key role in protection of the eye against reactive oxygen species. Cornea has a high activity of the pentose phosphate pathway and glucose-6-phosphate dehydrogenase activity. Glycation, the non-enzymic reaction between a free amino group in proteins and a reducing sugar, slowly inactivates gluthathione-related and other enzymes. In addition, glutathione can be also glycated. The presence of glutathione, and of the related enzymes has been also reported in other parts of the eye, such as ciliary body and trabecular meshwork, suggesting that the same enzyme systems are present in all tissues of the eye to generate NADPH and to maintain gluthatione in the reduced form. Changes of glutathione and related enzymes activity in lens, cornea, retina and other eye tissues, occur with ageing, cataract, diabetes, irradiation and administration of some drugs.
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Affiliation(s)
- Elena Ganea
- Institute of Biochemistry, Splaiul Independentei 296, Bucharest, Romania.
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Roffey SJ, Obach RS, Gedge JI, Smith DA. What is the Objective of the Mass Balance Study? A Retrospective Analysis of Data in Animal and Human Excretion Studies Employing Radiolabeled Drugs. Drug Metab Rev 2008; 39:17-43. [PMID: 17364879 DOI: 10.1080/03602530600952172] [Citation(s) in RCA: 158] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Mass balance excretion studies in laboratory animals and humans using radiolabeled compounds represent a standard part of the development process for new drugs. From these studies, the total fate of drug-related material is obtained: mass balance, routes of excretion, and, with additional analyses, metabolic pathways. However, rarely does the mass balance in radiolabeled excretion studies truly achieve 100% recovery. Many definitions of cutoff criteria for mass balance that identify acceptable versus unacceptable recovery have been presented as ad hoc statements without a strong rationale. To address this, a retrospective analysis was undertaken to explore the overall performance of mass balance studies in both laboratory animal species and humans using data for 27 proprietary compounds within Pfizer and extensive review of published studies. The review has examined variation in recovery and the question of whether low recovery was a cause for concern in terms of drug safety. Overall, mean recovery was greater in rats and dogs than in humans. When the circulating half-life of total radioactivity is greater than 50 h, the recovery tends to be lower. Excretion data from the literature were queried as to whether drugs linked with toxicities associated with sequestration in tissues or covalent binding exhibit low mass balance. This was not the case, unless the sequestration led to a long elimination half-life of drug-related material. In the vast majority of cases, sequestration or concentration of drug-related material in an organ or tissue was without deleterious effect and, in some cases, was related to the pharmacological mechanism of action. Overall, from these data, recovery of radiolabel would normally be equal to or greater than 90%, 85%, and 80% in rat, dog, and human, respectively. Since several technical limitations can underlie a lack of mass balance and since mass balance data are not sensitive indicators of the potential for toxicity arising via tissue sequestration, absolute recovery in humans should not be used as a major decision criteria as to whether a radiolabeled study has met its objectives. Instead, the study should be seen as an integral part of drug development answering four principal questions: 1) Is the proposed clearance mechanism sufficiently supported by the identities of the drug-related materials in excreta, so as to provide a complete understanding of clearance and potential contributors to interpatient variability and drug-drug interactions? 2) What are the drug-related entities present in circulation that are the active principals contributing to primary and secondary pharmacology? 3) Are there findings (low extraction recovery of radiolabel from plasma, metabolite structures indicative of chemically reactive intermediates) that suggest potential safety issues requiring further risk assessment? 4) Do questions 2 and 3 have appropriate preclinical support in terms of pharmacology, safety pharmacology, and toxicology? Only if one or more of these four questions remain unanswered should additional mass balance studies be considered.
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Affiliation(s)
- Sarah J Roffey
- Pharmacokinetics, Dynamics, and Metabolism, Pfizer, Inc., Sandwich, Kent, UK
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Gaynes BI, Torczynski E, Varro Z, Grostern R, Perlman J. Retinal toxicity of chloroquine hydrochloride administered by intraperitoneal injection. J Appl Toxicol 2008; 28:895-900. [DOI: 10.1002/jat.1353] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Ritter C, Renner AB, Wachtlin J, Bechrakis NE, Krause L. [Tamoxifen retinopathy: a case series of clinical and functional data]. Ophthalmologe 2008; 105:544-9. [PMID: 18415107 DOI: 10.1007/s00347-007-1677-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Tamoxifen is used in the treatment of selected patients with breast carcinoma. Rarely, it has been shown to cause ocular toxic effects including crystalline retinopathy. METHODS Retrospective analysis of clinical and functional (visual acuity, visual field, colour vision) data of a case series of eight female patients under tamoxifen therapy with electrophysiological examination. RESULTS Seven of eight patients complained of visual disturbances. In one case, examination showed crystalline deposits in the cornea and macular area. Three patients revealed changes in full-field and multifocal electroretinogram, and two had a pathological multifocal electroretinogram only. In six cases we applied a desaturated panel D-15 colour vision test; five of these showed some disorders. CONCLUSIONS Most tamoxifen patients who complained of visual disturbances showed electrophysiological changes, particularly in the multifocal electroretinogram and often without a certain morphological correlate. We recommend electrophysiological examination for patients with unclear visual deterioration who are receiving tamoxifen therapy.
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Affiliation(s)
- C Ritter
- Augenklinik , Charité - Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12200, Berlin, Deutschland.
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Richards F, Alderton W, Kimber G, Liu Z, Strang I, Redfern W, Valentin JP, Winter M, Hutchinson T. Validation of the use of zebrafish larvae in visual safety assessment. J Pharmacol Toxicol Methods 2008; 58:50-8. [DOI: 10.1016/j.vascn.2008.04.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Accepted: 04/26/2008] [Indexed: 10/22/2022]
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Bhandari N, Figueroa DJ, Lawrence JW, Gerhold DL. Phospholipidosis Assay in HepG2 Cells and Rat or Rhesus Hepatocytes Using Phospholipid Probe NBD-PE. Assay Drug Dev Technol 2008; 6:407-19. [PMID: 18537465 DOI: 10.1089/adt.2007.119] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Viertiö S, Laitinen A, Perälä J, Saarni SI, Koskinen S, Lönnqvist J, Suvisaari J. Visual impairment in persons with psychotic disorder. Soc Psychiatry Psychiatr Epidemiol 2007; 42:902-8. [PMID: 17846698 DOI: 10.1007/s00127-007-0252-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Accepted: 08/14/2007] [Indexed: 10/22/2022]
Abstract
BACKGROUND Persons with psychotic disorder may have poorer visual acuity (VA). The aim of the study is to investigate in a general population the prevalence of impaired habitual VA and self-reported difficulties in vision among persons with different psychotic disorders. METHOD A nationally representative sample of 6,663 persons aged 30 or older whose binocular VA for distance and for near vision was measured with current spectacles, if any. Diagnostic assessment of DSM-IV psychotic disorders used both SCID interview and case note data. Life-time ever diagnoses of psychotic disorders were classified into schizophrenia, other non-affective psychotic disorders and affective psychoses. RESULTS After adjusting for age and sex, schizophrenia was associated with significantly increased odds of having visual impairment for distance (OR 5.04, P < 0.0001) and for near vision (OR 6.22, P < 0.0001), while other psychotic disorders were not. Self-reported problems in VA were more common in persons with schizophrenia and other non-affective psychotic disorders than in the remaining study sample. Only 43.9% of persons with schizophrenia, compared with 69.7% in the total sample (chi(2) = 13.79, d.f. 1, P = 0.0002), had had their vision examined during the 5 years before the VA measurement. CONCLUSIONS Because persons with schizophrenia attend vision examinations substantially less frequently than others, and their vision is notably weaker, regular ocular evaluations should be included in physical health monitoring in psychotic disorders.
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Affiliation(s)
- Satu Viertiö
- Dept. of Mental Health and Alcohol Research, National Public Health Institute, Mannerheimintie 166, 00300, Helsinki, Finland.
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37
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Affiliation(s)
- Paul S Bernstein
- University of Utah, Department of Ophthalmology, John A. Moran Eye Center, Salt Lake City, Utah, USA
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Mecklenburg L, Schraermeyer U. An overview on the toxic morphological changes in the retinal pigment epithelium after systemic compound administration. Toxicol Pathol 2007; 35:252-67. [PMID: 17366319 DOI: 10.1080/01926230601178199] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Many medications that are administered systemically for nonocular conditions may evoke ocular toxicological complications. Therefore, the eye is routinely investigated histopathologically in preclinical in vivo toxicity studies. The retinal pigment epithelium is a likely target for systemically administered compounds, since the underlying choroid is highly vascularized. The specialized pigment epithelium has numerous functions that all maintain the integrity and function of photoreceptors. Consequently, toxic effects on the pigment epithelium will eventually affect the neural retina. The potential of pigment epithelial cells to respond to toxic injury is limited, but a standardized terminology to describe its morphological changes does not exist in the scientific literature. Detailed morphologic analysis, however, might allow early detection of retinotoxicity and may provide evidence on the underlying pathomechanism. We here review toxic effects on the pigment epithelium focusing in particular on the morphology of toxic cell injury. Morphological changes comprise hypertrophy, intracytoplasmic accumulation of cellular components, loss of cell polarity, degeneration, metaplasia, and formation of subretinal membranes. Some of these changes are reversible whereas others are permanent, leading to impaired function of the pigment epithelium and eventually to photoreceptor loss and retinal atrophy.
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Affiliation(s)
- Lars Mecklenburg
- ALTANA Pharma AG, Institute of Preclinical Drug Safety, Hamburg, 22885, Germany.
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Farombi EO. Genotoxicity of chloroquine in rat liver cells: protective role of free radical scavengers. Cell Biol Toxicol 2007; 22:159-67. [PMID: 16532284 DOI: 10.1007/s10565-006-0173-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2005] [Accepted: 12/15/2005] [Indexed: 10/24/2022]
Abstract
The genotoxic effect of chloroquine (CQ), a 4-aminoquinoline antimalarial drug was investigated in rat liver cells using the alkaline comet assay. Chloroquine (0-1000 micromol/L) significantly increased DNA strand breaks of rat liver cells dose-dependently. Rat liver cells exposed to CQ (100-500 micromol/L) and treated with endonuclease III and formamidopyrimidine-DNA glycosylase, the bacterial DNA repair enzymes that recognize oxidized pyrimidine and purine, respectively, showed greater DNA damage than those not treated with the enzymes, providing evidence that CQ induced oxidation of purines and pyrimidines. Treatment of cells with 5 mmol/L N-acetylcysteine, an intracellular reactive oxygen species (ROS) scavenger, and 100 micromol/L and 250 micromol/L deferoxamine, an established iron chelator, significantly decreased the CQ-induced strand breaks and base oxidation, respectively. Similarly, the formation of DNA strand breaks and oxidized bases was prevented by vitamin C (10 micromol/L) (a water-soluble antioxidant), quercetin (50 micromol/L) (an antioxidant flavonoid), and kolaviron (30 micromol/L and 90 micromol/L) (an antioxidant and a liver hepatoprotective phytochemical). The results indicate that the genotoxicity of CQ in rat liver cells might involve ROS and that free radical scavengers may elicit protective effects in these cells.
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Affiliation(s)
- E O Farombi
- Drug Metabolism and Toxicology Research Laboratories, Department of Biochemistry, College of Medicine, University of Ibadan, Nigeria.
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Toler SM, Noe D, Sharma A. Selective enhancement of cellular oxidative stress by chloroquine: implications for the treatment of glioblastoma multiforme. Neurosurg Focus 2006; 21:E10. [PMID: 17341043 DOI: 10.3171/foc.2006.21.6.1] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Chloroquine is used in the treatment of malaria, a disease caused by infection with the parasite Plasmodium. Although chloroquine appears to possess diverse pharmacological activity, its plasmodicidal activity results from augmentation of parasite oxidative stress. Chloroquine also appears to augment oxidative stress in metabolically active mammalian cells, including human astroglial cells. The authors propose that chloroquine may augment oxidative stress induced by radiotherapy in the treatment of glioblastoma multiforme, enhancing therapeutic efficacy. Such an effect would be consistent with the known pharmacological effects of chloroquine observed in Plasmodium. Other selective redox agents, such as tempol and artemisinin, should be investigated clinically for therapeutic benefit when coadministered with combined radio- and chemotherapy for cancer.
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Affiliation(s)
- Steven M Toler
- Department of Clinical Pharmacology, Pfizer, Incorporated, 50 Pequot Avenue, New London, Connecticut 06320, USA.
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Abstract
Many types of crystalline retinopathies have been described, associated with a myriad of medical conditions ranging from chronic retinal conditions to inherited systemic diseases. This comprehensive review summarizes the different types of crystalline retinopathies, including their clinical presentations, diagnostic criteria, pathology, and treatment options.
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Wickremasinghe S, Dansingani KK, Tranos P, Liyanage S, Jones A, Davey C. Ocular presentations of breast cancer. ACTA ACUST UNITED AC 2006; 85:133-42. [PMID: 17305726 DOI: 10.1111/j.1600-0420.2006.00737.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
CONTEXT Breast cancer is the most common malignancy in women, with increasing incidence in Europe and North America. The frequency of involvement of the eye and visual pathways is reported to be as high as 30% in patients with known metastatic disease. In some cases, ophthalmic involvement can be the first sign of metastatic spread. Metastasis occurs via the haematogenous route and predominantly involves the choroid. Metastases to other ocular structures, the orbit and the visual pathways have also been described. Paraneoplastic effects are rare but significant. TREATMENTS Different modalities are employed in the treatment of breast cancer and its metastases. These include chemotherapy and radiotherapy. The ocular adverse effects of these have been well described, but recently developed new treatment modalities, such as monoclonal antibodies, may have different side-effects. With the increasing incidence of breast cancer and the advent of new treatment strategies, the complications of the disease and the sequelae of therapy are highly relevant to both oncologists and ophthalmologists.
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Liu Y, Zhang Y, Liu J, Huang D. The role of reactive oxygen species in the herbicide acetochlor-induced DNA damage on Bufo raddei tadpole liver. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2006; 78:21-6. [PMID: 16513190 DOI: 10.1016/j.aquatox.2006.01.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2005] [Revised: 01/24/2006] [Accepted: 01/24/2006] [Indexed: 05/06/2023]
Abstract
After exposure of Bufo raddei tadpoles to acetochlor (ACETO) for 14 days, malondialdehyde (MDA) and DNA-single strand break (DNA-SSB) in livers were analyzed. An enhanced accumulation of MDA suggests that ACETO causes oxidative stress, and the significant increase in the level of DNA-SSB indicates that ACETO induces DNA damage in a dose-dependent manner as well. On the basis of the fact that oxidative stress is caused by excessive production of reactive oxygen species (ROS), and the present results, we speculate that ACETO-induced DNA damage may be a consequence of the generation of ROS. To evaluate this hypothesis, tadpoles were treated with ROS scavenger, N-acetyl-L-cysteine (NAC) or melatonin (MEL), prior to ACETO exposure. The decrease of DNA-SSB level and the increase of total antioxidant capability (TAC) show that ACETO-caused DNA damage can be attenuated by NAC and MEL. In addition, a negative correlation was observed between the extent of DNA damage and the level of TAC in tadpole liver. In conclusion, the results suggest that ACETO-induced DNA damage is mediated by ROS.
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Affiliation(s)
- Yang Liu
- School of Life Sciences, Lanzhou University, Lanzhou 730000, Gansu, China
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Attar M, Shen J, Ling KHJ, Tang-Liu D. Ophthalmic drug delivery considerations at the cellular level: drug-metabolising enzymes and transporters. Expert Opin Drug Deliv 2005; 2:891-908. [PMID: 16296785 DOI: 10.1517/17425247.2.5.891] [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: 11/05/2022]
Abstract
Ophthalmic drugs typically achieve < 10% ocular bioavailability. A drug applied to the surface of the eye may cross ocular-blood barriers where it may encounter metabolising enzymes and cellular transporters before it distributes to the site of action. Characterisation of ocular enzyme systems and cellular transporters and their respective substrate selectivity have provided new insight into the roles these proteins may play in ocular drug delivery and distribution. Altered metabolism and transport have been proposed to contribute to a number of ocular disease processes including inflammation, glaucoma, cataract, dry eye and neurodegeneration. As ocular enzyme and transport systems are better characterised, their properties become an integral consideration in drug design and development.
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Affiliation(s)
- Mayssa Attar
- Allergan, Inc., Department of Pharmacokinetics and Drug Metabolism, Irvine, CA 92612, USA
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Peters S, Reinthal E, Blitgen-Heinecke P, Bartz-Schmidt KU, Schraermeyer U. Inhibition of lysosomal degradation in retinal pigment epithelium cells induces exocytosis of phagocytic residual material at the basolateral plasma membrane. Ophthalmic Res 2005; 38:83-8. [PMID: 16352920 DOI: 10.1159/000090268] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2005] [Accepted: 08/15/2005] [Indexed: 11/19/2022]
Abstract
PURPOSE To analyze chloroquine-induced morphological changes in the retinal pigment epithelium (RPE) and Bruch's membrane (BM). METHODS Retina-choroid complexes of chloroquine-treated Long-Evans rats were analyzed by electron microscopy. RESULTS Intercellular spaces between the RPE cells and BM were enlarged. Residual material from phagosomes was released into these enlarged spaces. Debris accumulated within BM and encircled choriocapillaris endothelial cells. CONCLUSION There is a release of undegraded phagocytic material (rod outer segments) into the extracellular space between BM and RPE cells, following inhibition of lysosomal degradation. Electron-dense deposits in BM and choriocapillaris may lead to reduced oxygen and nutrition flow.
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Affiliation(s)
- Swaantje Peters
- University Eye Hospital Tübingen, Section of Experimental Vitreo-Retinal Surgery, Tübingen, Germany.
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Abstract
Recently, fluphenazine, a phenothiazine neuroleptic, has been associated with idiosyncratic retinopathy. Neuroleptic-induced retinopathy appears to be isolated to only a few structurally related phenothiazines, suggesting that the causality is not the result of dopamine antagonism. The chemical structure of fluphenazine is very similar to that of chlorpromazine and thioridazine, agents known to produce retinopathy. Like chlorpromazine and thioridazine, fluphenazine may be oxidized by retinal cytochrome P450 and/or myeloperoxidase to an electrophile, producing injury in susceptible patients.
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Affiliation(s)
- Steven M Toler
- Clinical Pharmacology, Pfizer Global Research and Development, Pfizer Inc., New London, CT 06320, USA.
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