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Berrios-Rivera JP, Street RL, Garcia Popa-Lisseanu MG, Kallen MA, Richardson MN, Janssen NM, Marcus DM, Reveille JD, Warner NB, Suarez-Almazor ME. Trust in physicians and elements of the medical interaction in patients with rheumatoid arthritis and systemic lupus erythematosus. ACTA ACUST UNITED AC 2006; 55:385-93. [PMID: 16739207 DOI: 10.1002/art.21988] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE To identify components of the patient-doctor relationship associated with trust in physicians. METHODS We assessed 102 patients with systemic lupus erythematosus (SLE) or rheumatoid arthritis (RA) seen at publicly funded hospitals in Houston, Texas. Patients completed a self-response survey examining patient perceptions of the medical encounter and trust in their physicians. Evaluated components of physicians' behaviors included: informativeness, sensitivity to concerns, reassurance and support, patient-centeredness, and participatory decision-making style. Scales were scored 0 to 10, with higher numbers indicating more positive perceptions of communication. RESULTS Seventy patients had RA and 32 SLE; 25% were white, 43% Latino, 31% African American, and 75% were female. Mean scores for the medical interaction and trust scales ranged from 6.2-7.1, indicating moderate degrees of positive perceptions. All components were highly and positively correlated with each other, and with trust, suggesting that these traits are all elements of a positive style of doctor-patient communication. In multivariate analysis, ethnicity, physicians' informativeness, physicians' sensitivity to concerns, patient-centeredness, disease activity, and patient trust in the US health care system were independent predictors of trust in physicians. A separate model examined the predictors of patient disclosure of information. Patient perceptions of physicians' patient-centeredness and severity of disease activity were independently predictive of patient disclosure of information. CONCLUSION In patients with SLE and RA, trust in physicians is significantly associated with patients' ethnicity and their perceptions about specific components of physicians' communication style. Trust in physicians can be improved by using a patient-centered approach, being sensitive to patient concerns, and providing adequate clinical information. Furthermore, patients appear to be more willing to disclose concerns when physicians use a patient-centered communication style.
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Marcus DM, Snodgrass WR. Effectiveness and safety of ginger in the treatment of pregnancy-induced nausea and vomiting. Obstet Gynecol 2005; 106:640; author reply 640-1. [PMID: 16135602 DOI: 10.1097/01.aog.0000177776.71861.f1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Marcus DM. A Commentary on the American Society for Clinical Pharmacology and Therapeutics Position Statement on Dietary Supplement Safety and Regulation. Clin Pharmacol Ther 2005; 78:114-7. [PMID: 16084845 DOI: 10.1016/j.clpt.2005.05.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2005] [Accepted: 05/04/2005] [Indexed: 11/26/2022]
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Marcus DM. What ails the FDA? N Engl J Med 2005; 352:2554. [PMID: 15962405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
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Garcia Popa-Lisseanu MG, Greisinger A, Richardson M, O'Malley KJ, Janssen NM, Marcus DM, Tagore J, Suarez-Almazor ME. Determinants of treatment adherence in ethnically diverse, economically disadvantaged patients with rheumatic disease. J Rheumatol 2005; 32:913-9. [PMID: 15868630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
OBJECTIVE To explore the determinants of adherence to medical recommendations, including drug therapy and appointment-keeping, among ethnically diverse and economically disadvantaged patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). METHODS Patients with RA and SLE were identified through chart review and were invited to participate in focus groups to examine their attitudes and beliefs regarding adherence to treatment and medical appointments. Eight focus groups (4 RA, 4 SLE) were conducted, with a total of 40 participants (22 SLE patients and 18 RA patients). Transcripts were analyzed using grounded theory techniques and qualitative analysis software to facilitate coding interpretation. RESULTS The majority of participants reported experiencing difficulty in adhering to their treatment at least occasionally. Both SLE and RA patients reported similar barriers to treatment adherence: fear of side effects, financial problems, difficulty in navigating the public health system, and perceived treatment inefficacy. RA and SLE patients also revealed barriers to appointment keeping, including difficulties in scheduling, financial costs, transportation, and functional impairment limiting their ability to attend the clinic. CONCLUSION Patients' perceptions of and experiences with the health system, physicians, medication effectiveness, and side effects influence their adherence to treatment and other medical recommendations. Strategies to improve adherence could include the following: attempting to modify patients' beliefs and perceptions regarding medication effectiveness, promoting realistic expectations about risk/benefit ratios, and improving access to health care by reducing barriers that limit the interaction between patients and the health system.
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Abstract
Herbal medicines are regarded by the public and some health care providers as gentle and safe, but there is no scientific basis for that belief. The active ingredients of plant extracts are chemicals that are similar to those in purified medications, and they have the same potential to cause serious adverse effects. This commentary summarizes recent data on the poor quality control and toxicity of herbal remedies and on the pharmacologic activities of ginger, which is used for treatment of morning sickness. There are no rigorous scientific studies of the safety of dietary supplements during pregnancy, and the Teratology Society has stated that it should not be assumed that they are safe for the embryo or fetus. Obstetricians should advise women not to expose their fetuses to the risks of herbal medicines.
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Brooks BJ, Ambati BK, Marcus DM, Ratanasit A. Photodynamic therapy for corneal neovascularisation and lipid degeneration. Br J Ophthalmol 2004; 88:840. [PMID: 15148229 PMCID: PMC1772199 DOI: 10.1136/bjo.2003.035071] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Marcus DM, Sheils WC, Young JO, McIntosh SB, Johnson MH, Alexander J, Samy CN. Radiotherapy for recurrent choroidal neovascularisation complicating age related macular degeneration. Br J Ophthalmol 2004; 88:114-9. [PMID: 14693787 PMCID: PMC1771925 DOI: 10.1136/bjo.88.1.114] [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] [Indexed: 11/04/2022]
Abstract
AIMS To report the safety and visual outcome data of external beam irradiation for recurrent choroidal neovascularisation complicating age related macular degeneration. METHODS Eighteen consecutive eyes received external beam irradiation with seven fractions of 2 Gy (total dose 14 Gy). The next 16 consecutive eyes received external beam irradiation with five fractions of 3 Gy (total dose 15 Gy). Main outcome measure was change in visual acuity. Secondary outcome variables were contrast sensitivity and fundus photographic/fluorescein angiographic progression. RESULTS The 3 Gy fraction group lost fewer lines of distance visual acuity at the three and six month follow up. At one year follow up, this difference was not maintained with 2 Gy fraction and 3 Gy fraction eyes. At one year follow up a decrease in visual acuity of three or more lines (moderate visual loss) occurred in 58% of 2 Gy and 42% of 3 Gy fraction eyes (p<0.36). At one year follow up a decrease in visual acuity of six or more lines (severe visual loss) occurred in 41% of 2 Gy eyes and 17% of 3 Gy eyes (p<0.23). At three months follow up, 3 Gy eyes were less likely (0%) than 2 Gy eyes (47%) to show moderate visual loss (p<0.003). However, Kaplan Meier curves estimate a significantly lower rate of severe visual loss in the 3 Gy group (p = 0.02). There were no significant differences in contrast sensitivity loss or fluorescein angiographic stabilisation rates. No evidence of radiation toxicity was observed. CONCLUSION Our results are consistent with trends for a palliative benefit with higher fraction sizes and doses. The radiobiologic differences between low and high fraction size groups in this study are modest and correlate with the modest and short term difference in visual outcomes. These trends support further investigation of radiotherapy using fraction sizes of 4 Gy or higher.
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Amato P, Marcus DM. Review of alternative therapies for treatment of menopausal symptoms. Climacteric 2003; 6:278-84. [PMID: 15006249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
Many women use alternative therapies to treat hot flushes and other menopausal symptoms. The purpose of this review is to summarize current information on the efficacy and safety of phytoestrogens and the herbal medicine black cohosh. A preponderance of evidence indicates that phytoestrogens are ineffective in treating hot flushes. Trials of black cohosh, many of which are small, of limited duration and of poor methodological quality, provide conflicting results, and at present it is unclear whether black cohosh is more effective than placebo. Although phytoestrogens and black cohosh appear to be safe when used for short periods of time, much larger and longer studies are needed to detect infrequent but potentially serious adverse events. Women who do not wish to take hormone therapy to treat menopausal symptoms should be encouraged to consider using selective serotonin reuptake inhibitors and other conventional therapeutic options.
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Hutson AM, Atmar RL, Marcus DM, Estes MK. Norwalk virus-like particle hemagglutination by binding to h histo-blood group antigens. J Virol 2003; 77:405-15. [PMID: 12477845 PMCID: PMC140602 DOI: 10.1128/jvi.77.1.405-415.2003] [Citation(s) in RCA: 205] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2002] [Accepted: 09/24/2002] [Indexed: 11/20/2022] Open
Abstract
Noroviruses are a major cause of epidemic acute nonbacterial gastroenteritis worldwide. Here we report our discovery that recombinant Norwalk virus virus-like particles (rNV VLPs) agglutinate red blood cells (RBCs). Since histo-blood group antigens are expressed on gut mucosa as well as RBCs, we used rNV VLP hemagglutination (HA) as a model system for studying NV attachment to cells in order to help identify a potential NV receptor(s). rNV VLP HA is dependent on low temperature (4 degrees C) and acidic pH. Of the 13 species of RBCs tested, rNV VLPs hemagglutinated only chimpanzee and human RBCs. The rNV VLPs hemagglutinated all human type O (11 of 11), A (9 of 9), and AB (4 of 4) RBCs; however, few human type B RBC samples (4 of 14) were hemagglutinated. HA with periodate- and neuraminidase-treated RBCs indicated that rNV VLP binding was carbohydrate dependent and did not require sialic acid. The rNV VLPs did not hemagglutinate Bombay RBCs (zero of seven) that lack H type 2 antigen, and an anti-H type 2 antibody inhibited rNV VLP HA of human type O RBCs. These data indicated that the H type 2 antigen functions as the rNV VLP HA receptor on human type O RBCs. The rNV VLP HA was also inhibited by rNV VLP-specific monoclonal antibody 8812, an antibody that inhibits VLP binding to Caco-2 cells. Convalescent-phase sera from NV-infected individuals showed increased rNV VLP HA inhibition titers compared to prechallenge sera. In carbohydrate binding assays, the rNV VLPs bound to synthetic Lewis d (Le(d)), Le(b), H type 2, and Le(y) antigens, and these antigens also inhibited rNV VLP HA of human type O RBCs. Overall, our results indicate that carbohydrate antigens in the gut are a previously unrecognized factor in NV pathogenesis.
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Marcus DM. Integrative medicine is a trojan horse. ARCHIVES OF INTERNAL MEDICINE 2002; 162:2381-3; author reply 2383. [PMID: 12418959 DOI: 10.1001/archinte.162.20.2381-a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Marcus DM. Alternative medicine and The Arthritis Foundation. ARTHRITIS AND RHEUMATISM 2002; 47:5-7. [PMID: 11932871 DOI: 10.1002/art1.10223] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Patel MR, Bains AK, O'Hara JP, Kallab AM, Marcus DM. Purtscher retinopathy as the initial sign of thrombotic thrombocytopenic purpura/hemolytic uremic syndrome. ARCHIVES OF OPHTHALMOLOGY (CHICAGO, ILL. : 1960) 2001; 119:1388-9. [PMID: 11545653 DOI: 10.1001/archopht.119.9.1388] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Marcus DM, Costarides AP, Gokhale P, Papastergiou G, Miller JJ, Johnson MH, Chaudhary BA. Sleep disorders: a risk factor for normal-tension glaucoma? J Glaucoma 2001; 10:177-83. [PMID: 11442179 DOI: 10.1097/00061198-200106000-00006] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To determine the prevalence of sleep-related symptoms and sleep-related breathing disorders by polysomnography in patients with normal-tension glaucoma (NTG). PATIENTS AND METHODS This comparative case series included 23 patients with NTG, 14 NTG suspects, and 30 comparison patients without NTG. A sleep history was obtained and determined to be positive or negative. Polysomnography was offered for patients with a positive sleep history. Prevalence of a positive sleep history and prevalence of sleep disorders were the main outcome measures. RESULTS The NTG, NTG suspect, and comparison groups did not differ with respect to age, body mass index, systemic disease, gender, or race. Thirteen (57%) of 23 patients with NTG, 6 (43%) of 14 NTG suspects, and 1 (3%) of 30 comparison patients had a positive sleep history (P = 0.001). Nine of 13 patients with NTG and four of six NTG suspects with a positive sleep history chose to undergo polysomnography. Seven (78%) of nine patients with NTG and all four NTG suspects undergoing polysomnography were diagnosed with a sleep disorder. Five patients with NTG had sleep apnea and two had sleep hypopnea. Two NTG suspects had sleep apnea; one had sleep hypopnea; and one had upper airway resistance syndrome. The one comparison patient with a positive sleep history had upper airway resistance syndrome by polysomnography. CONCLUSIONS Sleep-disturbed breathing may be a risk factor for NTG. Although we do not provide evidence for a cause-and-effect relationship, various physiologic factors produced by sleep-disturbed breathing may play a significant role in the pathogenesis of this optic neuropathy. We recommend obtaining a sleep history from patients with NTG and performing polysomnography in those patients with sleep disturbance symptoms.
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Marcus DM, Lynn J, Miller JJ, Chaudhary O, Thomas D, Chaudhary B. Sleep disorders: a risk factor for pseudotumor cerebri? J Neuroophthalmol 2001; 21:121-3. [PMID: 11450902 DOI: 10.1097/00041327-200106000-00014] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To determine whether sleep-related breathing disorders are common in patients with idiopathic intracranial hypertension. MATERIALS AND METHODS Medical records of 53 patients with idiopathic intracranial hypertension from a tertiary center neuroophthalmology practice were reviewed. Thirty-seven patients were identified who had a history of snoring, difficulty sleeping, or daytime somnolence. The data from polysomnograms were tabulated to determine the frequency of apneas, hypopneas, and arousals. RESULTS Fourteen of 37 patients with idiopathic intracranial hypertension and symptoms of sleep disturbance underwent polysomnography. There were two men and 12 women varying in age from 24 to 58 years (mean, 39.4 +/- 11.9). These patients were obese with body mass indexes varying from 33.0 to 63.2 (mean, 46.0 +/- 9.5). A diagnosis of sleep apnea was made in six and upper airway resistance syndrome in seven patients. CONCLUSIONS Sleep-related breathing problems were common in our patients with idiopathic intracranial hypertension. Obesity was common in these patients and may be playing a causative role in sleep apnea and idiopathic intracranial hypertension. It is suggested that idiopathic intracranial hypertension patients who have symptoms of sleep disturbance should be further evaluated for the presence of sleep-related breathing problems.
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Marcus DM, Schlossman SF. In memoriam. Elvin Abraham Kabat, September 1, 1914-June 16, 2000. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:3635-6. [PMID: 11238598 DOI: 10.4049/jimmunol.166.6.3635] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Marcus DM. How should alternative medicine be taught to medical students and physicians? ACADEMIC MEDICINE : JOURNAL OF THE ASSOCIATION OF AMERICAN MEDICAL COLLEGES 2001; 76:224-229. [PMID: 11242570 DOI: 10.1097/00001888-200103000-00007] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Advocates of alternative medicine are critical of current medical curricula, and have proposed fundamental changes, including the introduction of "integrative medicine" programs to teach alternative medicine. Medical educators have not replied to these criticisms, and have not developed basic curricula in alternative medicine. The author analyzes the alleged deficiencies in medical education, which are based on misrepresentations of medicine and medical training. (For example, critics state that physicians ignore mind-body interactions; in response, several examples are given to show that training physicians to consider the whole person and to identify and address emotional and social problems-the biopsycho-social model-are central tenets of medical education.) The author also examines fundamental differences between traditional and alternative medicine (e.g., their different attitudes toward the importance of evidence; the vitalistic versus the biomedical models of health and disease) that are central to the issue of how alternative medicine should be taught. He concludes that physicians need additional education in order to provide guidance to patients, but teaching about alternative medicine should be evidence-based, not merely the transmission of unproven practices.
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Marcus DM, Sheils W, Johnson MH, McIntosh SB, Leibach DB, Maguire A, Alexander J, Samy CN. External beam irradiation of subfoveal choroidal neovascularization complicating age-related macular degeneration: one-year results of a prospective, double-masked, randomized clinical trial. ARCHIVES OF OPHTHALMOLOGY (CHICAGO, ILL. : 1960) 2001; 119:171-80. [PMID: 11176977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
OBJECTIVES To determine the effects of low-dose external beam irradiation compared with observation on the visual function of eyes with subfoveal choroidal neovascularization (CNV) complicating age-related macular degeneration (ARMD). DESIGN Prospective, double-masked, randomized clinical trial. Patients randomized to the radiation group received external beam irradiation at a dose of 14 Gy in 7 fractions of 2 Gy. Patients randomized to the observation group received sham radiation. SETTING Tertiary care retinal referral practice. PATIENTS Individuals with classic, mixed, or occult subfoveal CNV secondary to ARMD. MAIN OUTCOME MEASURES Change in visual acuity from baseline to specified time periods. Secondary outcome variables were contrast sensitivity and fundus photographic/fluorescein angiographic progression. RESULTS Forty-two eyes were randomized to observation; 41 eyes, to radiation. Baseline characteristics and demographics did not differ between groups. The median distance visual acuity (DVA) in radiation-treated eyes decreased from 20/80 at baseline to 20/320 (mean loss rate, 4.14 lines) at 1-year follow-up. The median DVA in observation group eyes decreased from 20/125 at baseline to 20/250 (mean loss rate, 3.39 lines) at 1-year follow-up. There were no statistically significant differences in changes in DVA, contrast sensitivity, or fluorescein angiographic progression from baseline between groups at any follow-up period. CONCLUSIONS At 1-year follow-up, low-dose external beam irradiation at 14 Gy in 7 fractions of 2 Gy is neither beneficial nor harmful for subfoveal CNV complicating ARMD.
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Brooks SE, Gu X, Samuel S, Marcus DM, Bartoli M, Huang PL, Caldwell RB. Reduced severity of oxygen-induced retinopathy in eNOS-deficient mice. Invest Ophthalmol Vis Sci 2001; 42:222-8. [PMID: 11133872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023] Open
Abstract
PURPOSE Exposure of premature human infants to hyperoxia results in the obliteration of developing retina capillaries, leading to a vision-threatening retinopathy termed retinopathy of prematurity (ROP). The authors hypothesized that this process may be mediated in part by endothelial nitric oxide (NO)-derived oxidants such as peroxynitrite and tested this hypothesis in a mouse model of ROP. METHODS Normal mice, mice treated with the nitric oxide synthase (NOS) inhibitor N:(G)-nitro-L-arginine (L-NNA), and knockout mice carrying a homozygous targeted disruption of the gene for endothelial NOS (eNOS) were studied in an experimental model of ROP. Retinas were compared for extent of capillary obliteration in hyperoxia, vascular endothelial growth factor (VEGF) expression, nitrotyrosine formation, and vitreous neovascularization. RESULTS Oxygen-induced retinal vaso-obliteration was significantly reduced by L-NNA treatment (43% decrease from controls). The eNOS-deficient mice showed a similar reduction in vaso-obliteration (46% decrease from controls), and vitreous neovascularization was also substantially reduced (threefold decrease). Retinal nitrotyrosine formation, a measure of in situ peroxynitrite modification of proteins, was significantly elevated in normal mice during hyperoxia, in a spatial and temporal pattern consistent with a role in oxygen-induced vaso-obliteration. This was not seen in eNOS-deficient mice. VEGF expression was similar in both groups of mice, although suppression in hyperoxia was slightly blunted in eNOS-deficient mice. CONCLUSIONS These data suggest a role for NO and peroxynitrite in the pathogenesis of ROP. Therapies aimed at modulation of eNOS activity may have therapeutic potential for preventing ROP.
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Marcus DM, Rustgi AK, Defoe D, Kucherlapati R, Edelmann W, Hamasaki D, Liou GI, Smith SB. Ultrastructural and ERG findings in mice with adenomatous polyposis coli gene disruption. Mol Vis 2000; 6:169-77. [PMID: 10982921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
PURPOSE In order to continue the previous morphological studies of eyes from mice with adenomatous polyposis coli (APC) gene mutation at codon 1638, we determined the ultrastructural and electrophysiologic characteristics of these eyes. METHODS Thirty-eight eyes from 20 mice heterozygous for APC gene mutation and 22 eyes from 11 wild-type mice were examined by light microscopy. Six APC-modified eyes without light microscopic abnormalities, four APC-modified eyes with focal light microscopic abnormalities, and four wild-type eyes were examined by electron microscopy. Electroretinograms were recorded from four APC-modified and three wild-type mice. RESULTS Four of 38 APC-modified eyes demonstrated ultrastructural evidence of focal RPE cells with increased melanosome production and atrophy. Other areas of the RPE in these four eyes demonstrated no ultrastructural abnormalities. Three APC-modified eyes demonstrated electron and light microscopic evidence of RPE hyperplasia. Electron microscopic examination of APC-modified eyes without light microscopic evidence of abnormalities demonstrated no ultrastructural differences from age-matched controls. Electroretinography demonstrated no differences in the b-wave or c-wave amplitudes between APC-modified and wild-type mice. CONCLUSIONS While light microscopic RPE alterations are observed in these APC-modified mice, the absence of a generalized, ultrastructural murine RPE defect is in contradistinction to observations in electron microscopic investigations of humans with colonic polyposis, pigmented ocular fundus lesions, and APC gene mutations between codons 463 and 1444. Our results in mice with APC mutation at codon 1638, however, are consistent with a previously identified association between the expression of pigmented ocular fundus lesions and region-specific mutation in the human APC gene. The APC protein may possess a physiologic function for both retinal and RPE development.
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