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This study aimed to assess retinal alterations following membrane peeling procedures using novel ILM Forceps with laser ablated surface with the help of intraoperative optical coherence tomography (iOCT). A post-hoc analysis was performed to evaluate iOCT findings in eyes that underwent membrane peeling procedures with the novel ILM Forceps. Pre-peel and post-peel iOCT videos and images were evaluated for each eye to assess for post-peel anatomic alterations. Surgical video/iOCT scan correlation was conducted to evaluate the etiology of anatomic alterations. Thirty-two eyes were included in the analysis. Three eyes (9%) had focal full thickness retinal elevations identified on iOCT following tissue-instrument interaction with the ILM Forceps. Two eyes (6%) had focal inner retinal elevations and one eye (3%) had a full-thickness retinal elevation that were not related to direct tissue-instrument interaction but rather indirect peeling forces. iOCT-identified architectural alterations related to direct-tissue instrument interaction were relatively infrequent (< 10%) with similar frequency to previously reported alterations with other surgical instruments.
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Retina , Instrumentos Cirúrgicos , Tomografia de Coerência Óptica , Humanos , Tomografia de Coerência Óptica/métodos , Masculino , Retina/cirurgia , Retina/diagnóstico por imagem , Retina/patologia , Feminino , Idoso , Pessoa de Meia-Idade , Vitrectomia/métodos , Vitrectomia/instrumentação , Vitrectomia/efeitos adversos , Membrana Epirretiniana/cirurgia , Membrana Epirretiniana/diagnóstico por imagemRESUMO
PURPOSE: To compare fundus autofluorescence (FAF) and spectral domain optical coherence tomography (OCT) measurements of geographic atrophy (GA) area and to analyze lesion area changes measured by spectral domain OCT in GATHER1. DESIGN: An assessment reliability analysis using prospective, randomized, double-masked phase 2/3 clinical trial data. METHODS: GATHER1 examined the efficacy and safety of avacincaptad pegol (ACP) for GA treatment. A post hoc analysis was performed to identify correlations between FAF- and OCT-based measurements of GA. GA area was measured on blue-light FAF images using semiautomatic segmentation software with support from OCT and near-infrared imaging. Machine-learning enhanced, multilayer segmentation of OCT scans were reviewed by human readers, and segmentation errors were corrected as needed. GA area was defined as total RPE loss on cross-sectional B scans. Time points included Months 0, 6, 12, and 18. Additionally, OCT-based GA-area changes between ACP and sham were analyzed. RESULTS: There was a strong correlation (r = 0.93) between FAF and OCT GA area measurements that persisted through 18 months. Mean (SD) differences between OCT and FAF GA measurements were negligible: 0.11 mm2 (1.42) at Month 0, 0.03 mm2 (1.62) at Month 6, -0.17 mm2 (1.81) at Month 12, and -0.07 mm2 (1.78) at Month 18. OCT assessments of GA growth revealed a 30% and 27% reduction at Months 12 and 18, respectively, between ACP and sham, replicating FAF measurements from GATHER1. CONCLUSIONS: The strong correlation between blue FAF and OCT measurements of GA area supports OCT as a reliable method to measure GA lesion area in clinical trials.
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BACKGROUND: Screening for hydroxychloroquine (HCQ) retinopathy is crucial to detecting early disease. A novel machine-learning-based optical coherence tomography (OCT) biomarker, Ellipsoid Zone (EZ) At-Risk, can quantitatively measure EZ alterations and at-risk areas for progressive EZ loss in a fully automated fashion. The purpose of this analysis was to compare the EZ At-Risk burden in eyes with HCQ toxicity to eyes without toxicity. METHODS: IRB-approved image analysis study of 83 subjects on HCQ and 44 age-matched normal subjects. SD-OCT images were reviewed for evidence of HCQ retinopathy. A ML-based, fully automatic measurement of the percentage of the macular area with EZ At-Risk was performed. RESULTS: The mean age for HCQ subjects was 67.1 ± 13.2 years and 64.2 ± 14.3 years for normal subjects. The mean EZ At-Risk macular burden in the "toxic" group (n = 38) was significantly higher (10.7%) compared to the "non-toxic" group (n = 45; 2.2%; p = 0.023) and the "normal" group (1.4%; p = 0.012). Additionally, the amount of EZ At-Risk burden was significantly correlated with the HCQ dose based on the actual (p = 0.016) and ideal body weight (p = 0.033). CONCLUSIONS: The novel biomarker EZ-At Risk was significantly higher in subjects with evidence of HCQ retinopathy as well as significantly associated with HCQ dose. This novel biomarker should be further evaluated as a potential screening tool for subjects on HCQ.
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In this longitudinal retrospective image analysis, conducted on patients diagnosed with dry age-related macular degeneration (AMD) and 5 years of follow-up imaging data, the study aimed to investigate the relationship between ellipsoid zone (EZ) integrity on spectral domain optical coherence tomography (SD-OCT) and visual acuity (VA). Using a machine learning-enabled feature extraction tool, quantitative EZ parameters were derived from SD-OCT images. The analysis revealed significant correlations between EZ integrity metrics and VA. Eyes with excellent VA (≥20/25 Snellen) exhibited higher EZ integrity, including less EZ attenuation, thicker ellipsoid zone-retinal pigment epithelium (EZ-RPE) thickness, and higher EZ intensity, in contrast to eyes with worse VA (≤20/40 Snellen). Additionally, eyes with geographic atrophy (GA) in the foveal region displayed compromised EZ integrity compared to those without GA. Notably, baseline EZ integrity metrics were predictive of future VA loss. These findings suggest that quantitative SD-OCT measurements of EZ integrity could potentially detect early changes in dry AMD and serve as valuable indicators for predicting future functional outcomes. Furthermore, these measurements hold promise for use in clinical trial screenings, offering insights into the progression of the disease and its impact on visual acuity. This study underscores the importance of EZ integrity assessment in understanding and managing dry AMD.
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Purpose: This report aims to highlight the wide spectrum of ophthalmic adverse events associated with erdafitinib, a fibroblast growth factor inhibitor that blocks activation of the mitogen-activated protein kinase kinase (MAPK/MEK) cascade. The purpose of this report is to describe a case of erdafitinib-associated bilateral outer retinal alterations in the MEK-associated retinopathy spectrum and rapid onset bilateral total cataracts following a 20-month course of erdafitinib therapy. Observations: A 69 year old male with metastatic bladder cancer presented 47 days following treatment initiation with daily erdafitinib (8-mg) with mild new subretinal fluid and minimal associated subretinal debris in the left eye and accentuation/thickening of the interdigitation zone in the right eye. Over the course of treatment, improvements were noted, particularly with erdafitinib dose reduction. At 20 months, both eyes developed rapidly progressive mature cataracts with significant visual changes, necessitating bilateral cataract extraction. Conclusions and importance: The potential stability of moderate outer retinal changes (i.e., ellipsoid zone/interdigitation zone, subretinal fluid) while continuing erdafitinib therapy is highlighted in this report. In addition, the importance of continued ophthalmic surveillance is emphasized given the possible association of anterior segment adverse events with long-term erdafitinib use.
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OBJECTIVE: To evaluate the incidence of bacillary layer detachment in patients with neovascular age-related macular degeneration (nAMD) and their response to anti-VEGF therapy. DESIGN: Post hoc analysis of the brolucizumab 6-mg and aflibercept 2-mg arms from the HAWK clinical trial, a 48-week, prospective, double-masked, phase III trial. PARTICIPANTS: Participants (n = 652 and 652 eyes) randomized to brolucizumab 6-mg and aflibercept 2-mg arms from HAWK (NCT02307682). METHODS: Spectral-domain OCT scans were obtained at 4-week intervals throughout the HAWK trial and segmented automatically using a proprietary, machine learning-enabled, higher-order feature extraction platform. MAIN OUTCOME MEASURES: The incidence of bacillary layer detachment and effect of anti-VEGF therapy in these eyes on best-corrected visual acuity (BCVA), central subfield thickness (CST), retinal fluid volumes, subretinal hyper-reflective material (SHRM) volume, and ellipsoid zone (EZ) integrity from baseline to week 48. RESULTS: Classic bacillary layer detachment was identified in 7.2% (47/652) of eyes, demonstrating worse BCVA and higher CST, EZ total attenuation, subretinal fluid (SRF), and SHRM volume at baseline than eyes without bacillary layer detachment. Anti-VEGF treatment resulted in resolution of bacillary layer detachment in 97.9% of eyes by week 48. In eyes with bacillary layer detachment, anti-VEGF treatment improved BCVA and decreased SRF and SHRM volume; however, eyes with bacillary layer detachment never reached the level of BCVA improvement as eyes without bacillary layer detachment. A greater proportion of eyes with bacillary layer detachment had high-exudative volatility (increased mean standard deviation after loading dose) of CST, SRF, and total fluid than eyes without bacillary layer detachment (P < 0.05 for each comparison). CONCLUSIONS: Bacillary layer detachment, an OCT signature representing photoreceptor schisis, is identifiable in a notable proportion of eyes with nAMD. Anti-VEGF therapy resulted in a very high proportion of bacillary layer detachment resolution with significantly decreased SRF and SHRM volumes. The majority of eyes with bacillary layer detachment have high-exudative volatility, which may be associated with lower BCVA outcomes. The presence of bacillary layer detachment may provide an important imaging biomarker to be considered for clinical trial inclusion/exclusion based on trial design and therapeutic goals because of its unique behavior. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
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Inibidores da Angiogênese , Injeções Intravítreas , Receptores de Fatores de Crescimento do Endotélio Vascular , Proteínas Recombinantes de Fusão , Descolamento Retiniano , Tomografia de Coerência Óptica , Acuidade Visual , Degeneração Macular Exsudativa , Humanos , Tomografia de Coerência Óptica/métodos , Inibidores da Angiogênese/administração & dosagem , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Receptores de Fatores de Crescimento do Endotélio Vascular/administração & dosagem , Método Duplo-Cego , Estudos Prospectivos , Masculino , Degeneração Macular Exsudativa/tratamento farmacológico , Degeneração Macular Exsudativa/diagnóstico , Degeneração Macular Exsudativa/complicações , Descolamento Retiniano/diagnóstico , Descolamento Retiniano/tratamento farmacológico , Descolamento Retiniano/etiologia , Feminino , Idoso , Proteínas Recombinantes de Fusão/administração & dosagem , Anticorpos Monoclonais Humanizados/uso terapêutico , Anticorpos Monoclonais Humanizados/administração & dosagem , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Seguimentos , Fundo de Olho , Angiofluoresceinografia/métodos , Idoso de 80 Anos ou mais , Relação Dose-Resposta a DrogaRESUMO
BACKGROUND: The development and testing of a deep learning (DL)-based approach for detection and measurement of regions of Ellipsoid Zone (EZ) At-Risk to study progression in nonexudative age-related macular degeneration (AMD). METHODS: Used in DL model training and testing were 341 subjects with nonexudative AMD with or without geographic atrophy (GA). An independent dataset of 120 subjects were used for testing model performance for prediction of GA progression. Accuracy, specificity, sensitivity, and intraclass correlation coefficient (ICC) for DL-based EZ At-Risk percentage area measurement was calculated. Random forest-based feature ranking of EZ At-Risk was compared to previously validated quantitative OCT-based biomarkers. RESULTS: The model achieved a detection accuracy of 99% (sensitivity = 99%; specificity = 100%) for EZ At-Risk. Automatic EZ At-Risk measurement achieved an accuracy of 90% (sensitivity = 90%; specificity = 84%) and the ICC compared to ground truth was high (0.83). In the independent dataset, higher baseline mean EZ At-Risk correlated with higher progression to GA at year 5 (p < 0.001). EZ At-Risk was a top ranked feature in the random forest assessment for GA prediction. CONCLUSIONS: This report describes a novel high performance DL-based model for the detection and measurement of EZ At-Risk. This biomarker showed promising results in predicting progression in nonexudative AMD patients.
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The current study describes the development and assessment of innovative, machine learning (ML)-based approaches for automated detection and pixel-accurate measurements of regions with geographic atrophy (GA) in late-stage age-related macular degeneration (AMD) using optical coherence tomography systems. 900 OCT volumes, 100266 B-scans, and en face OCT images from 341 non-exudative AMD patients with or without GA were included in this study from both Cirrus (Zeiss) and Spectralis (Heidelberg) OCT systems. B-scan and en face level ground truth GA masks were created on OCT B-scan where the segmented ellipsoid zone (EZ) line, retinal pigment epithelium (RPE) line, and bruchs membrane (BM) line overlapped. Two deep learning-based approaches, B-scan level and en face level, were trained. The OCT B-scan model had detection accuracy of 91% and GA area measurement accuracy of 94%. The en face OCT model had detection accuracy of 82% and GA area measurement accuracy of 96% with primary target of hypertransmission on en face OCT. Accuracy was good for both devices tested (92-97%). Automated lesion size stratification for CAM cRORA definition of 250um minimum lesion size was feasible. High-performance models for automatic detection and segmentation of GA area were achieved using OCT systems and deep learning. The automatic measurements showed high correlation with the ground truth. The en face model excelled at identification of hypertransmission defects. The models performance generalized well across device types tested. Future development will include integration of both models to enhance feature detection across GA lesions as well as isolating hypertransmission defects without GA for pre-GA biomarker extraction.
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Purpose: The purpose of the study was to evaluate the functional success rates using dacryoscintigraphy (DSG) after transcanalicular diode laser dacryocystorhinostomy (TDL-DCR). Methods: In this retrospective study, we investigated the records of 56 patients who underwent TDL-DCR for unilateral primary acquired nasolacrimal duct obstruction and anatomic patency was achieved. The lacrimal drainage systems of the other eyes of the patients were normal and were selected as control group. The functional success was evaluated with tear transit time (TT) on DSG and epiphora complaints' score (ECS) at postoperative 6 months. Results: Twenty-two (39%) of the patients were male and 34 (61%) were female, with a mean age of 46.6 (21-64). The dacryoscintigraphic findings of the operated and healthy eyes showed that there was statistically insignificant prolongation in the tear TT at the operated side at postoperative 6th month (P > 0.05). The mean ECS of operated eyes was 0.89. Functional success was achieved in 43 (76.8%) patients when the ECS of 0 and 1 was accepted as successful. A statistically significant delay in drainage was observed in DSG in all of the cases with epiphora score of 2 and 3 (P < 0.05). The tear TT was prolonged with the age increase (P < 0.05), but there was no significant difference concerning the gender. Conclusion: DSG is an effective tool to evaluate the functional success of TDL-DCR.
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Dacriocistorinostomia/métodos , Doenças do Aparelho Lacrimal/cirurgia , Terapia a Laser/métodos , Lasers Semicondutores/uso terapêutico , Ducto Nasolacrimal/cirurgia , Cintilografia/métodos , Adulto , Feminino , Humanos , Doenças do Aparelho Lacrimal/diagnóstico , Masculino , Pessoa de Meia-Idade , Ducto Nasolacrimal/diagnóstico por imagem , Estudos Retrospectivos , Resultado do Tratamento , Adulto JovemRESUMO
Choroidal osteoma (CO) is a rare, benign, and usually unilateral intraocular tumor composed of mature bone affecting the choroid. It appears as slightly elevated, yellowish-white, or orange choroidal mass with well-defined borders. It is commonly encountered in young female adults. Here, we report findings of a 4-week-old premature baby with CO in her left eye which was detected during a routine examination for "retinopathy of prematurity." We believe that this case is the youngest patient reported with CO which showing that this pathology can be encountered even in a newborn.
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Neoplasias Ósseas/patologia , Neoplasias da Coroide/patologia , Recém-Nascido Prematuro , Osteoma/patologia , Feminino , Angiofluoresceinografia , Idade Gestacional , Humanos , Lactente , Tomografia de Coerência ÓpticaRESUMO
OBJECTIVES: To evaluate the effect of carotid artery disease on retinal morphology by means of spectral domain optical coherence tomography (SD-OCT). MATERIALS AND METHODS: We examined 23 eyes with internal carotid artery (ICA) stenosis and 24 age- and gender-matched healthy eyes as a control group in this prospective, case-control study. Compherensive ophthalmic examination and SD-OCT scan were performed to all the patients. The average RNFL and macular thicknesses (MT) in the nine macular ETDRS areas were the major OCT measurements for our study. RESULTS: Although all of the average RNFL and MT measurements were lower in the ICA stenosis group, only the total MT and outer ETDRS area (temporal/superior/nasal/inferior outer macula) values were found to be significantly thinner compared to the control group (p=0.004, p=0.009, p<0.001, p=0.002, and p=0.001, respectively). CONCLUSION: In addition to our knowledge about the effects of ICA stenosis on the retino-choroidal circulation, we found that OCT measurements may be beneficial in the early detection of ocular damage due to ICA stenosis.
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BACKGROUND: Alveolar echinococcosis (AE) is a potentially fatal and chronically progressive infestation produced by the multivesicular metacestode of Echinococcus multilocularis, which most commonly affects the liver, lungs, and brain. CASE REPORT: We present a case of AE in which an alveolar cyst, as a result of exophytic growth, adhered to intra-abdominal and pelvic organs and metastasized to the breast. Exploration showed that the exophytic cyst in the liver filled the entire abdominal cavity, reaching to the uterus and bladder, and was adherent to the neighboring tissues and organs. This cystic lesion was totally excised, as was the 7×6 cm cystic lesion in the right breast. CONCLUSIONS: The liver is the most common site for echinococcal cysts of the pastoral strains (>65%), followed by the lungs (25%); the cyst is seen less frequently in the spleen, kidneys, heart, bone, and central nervous system. AE must be considered in areas where liver cysts are endemic and in the presence of a liver cyst, and the organs where a metastasis is possible must be thoroughly investigated. Furthermore, in these areas, when cystic disorders of the breast are present, AE should not be discounted among possible definitive diagnoses.
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Although epidemiologic studies indicate that combined exposure to cigarette smoke and alcohol increase the risk and severity of liver diseases, the molecular mechanisms responsible for hepatotoxicity are unknown. Similarly, emerging evidence indicates a linkage among hepatic steatosis and cardiovascular disease. Herein, we hypothesize that combined exposure to alcohol and environmental tobacco smoke (ETS) on a hypercholesterolemic background increases liver injury through oxidative/nitrative stress, hypoxia, and mitochondrial damage. To test this, male apoE(-/-) mice were exposed to an ethanol-containing diet, ETS alone, or a combination of the two, and histology and functional endpoints were compared to filtered-air-exposed, ethanol-naïve controls.Whereas ethanol consumption induced a mild steatosis, combined exposure to ethanol + ETS resulted in increased hepatic steatosis, inflammation, alpha-smooth muscle actin, and collagen. Exposure to ethanol + ETS induced the largest increase in CYP2E1 and iNOS protein, as well as increased 3-nitrotyrosine, mtDNA damage, and decreased cytochrome c oxidase protein, compared to all other groups. Similarly, the largest increase in HIF1alpha expression was observed in the ethanol + ETS group, indicating enhanced hypoxia. These studies demonstrate that ETS increases alcohol-dependent steatosis and hypoxic stress. Therefore, ETS may be a key environmental "hit" that accelerates and exacerbates alcoholic liver disease in hypercholesterolemic apoE(-/-) mice.
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Etanol/efeitos adversos , Fígado Gorduroso/etiologia , Fígado/metabolismo , Modelos Biológicos , Fumar/efeitos adversos , Actinas/genética , Actinas/metabolismo , Animais , Apolipoproteínas E/deficiência , Citocromo P-450 CYP2E1/genética , Citocromo P-450 CYP2E1/metabolismo , Dano ao DNA , Etanol/administração & dosagem , Fígado Gorduroso/metabolismo , Fígado Gorduroso/fisiopatologia , Regulação da Expressão Gênica , Hipercolesterolemia/genética , Hipóxia , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Fígado/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Estresse Oxidativo , Fatores de RiscoRESUMO
Environmental tobacco smoke (ETS) exposure and alcohol (EtOH) consumption often occur together, yet their combined effects on cardiovascular disease development are currently unclear. A shared feature between ETS and EtOH exposure is that both increase oxidative stress and dysfunction within mitochondria. The hypothesis of this study was that simultaneous EtOH and ETS exposure will significantly increase atherogenesis and mitochondrial damage compared to the individual effects of either factor (ETS or EtOH). To test this hypothesis, apoE(-/-) mice were exposed to EtOH and/or ETS singly or in combination for 4 weeks and compared to filtered air, nonalcohol controls. Atherosclerotic lesion formation (oil red O staining of whole aortas), mitochondrial DNA (mtDNA) damage, and oxidant stress were assessed in vascular tissues. Combined exposure to ETS and EtOH had the greatest impact on atherogenesis, mtDNA damage, and oxidant stress compared to filtered air controls, alcohol, or ETS-exposed animals alone. Because moderate EtOH consumption is commonly thought to be cardioprotective, these studies suggest that the potential influence of common cardiovascular disease risk factors, such as tobacco smoke exposure or hypercholesterolemia, on the cardiovascular effects of alcohol should be considered.
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Consumo de Bebidas Alcoólicas/efeitos adversos , Aterosclerose/etiologia , Aterosclerose/genética , Dano ao DNA , DNA Mitocondrial/metabolismo , Poluição por Fumaça de Tabaco/efeitos adversos , Consumo de Bebidas Alcoólicas/genética , Consumo de Bebidas Alcoólicas/metabolismo , Animais , Apolipoproteínas E/metabolismo , Aterosclerose/sangue , Aterosclerose/metabolismo , DNA Mitocondrial/genética , Hipercolesterolemia/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estresse Oxidativo/fisiologiaAssuntos
Fístula Biliar/diagnóstico , Fístula Biliar/parasitologia , Equinococose Hepática/diagnóstico , Imageamento por Ressonância Magnética , Fístula Biliar/cirurgia , Colecistite/parasitologia , Colecistite/cirurgia , Diagnóstico Diferencial , Equinococose Hepática/cirurgia , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Tricaine (MS-222) is used commonly for sedation, immobilization, and anesthesia of poikilothermic animals. The anesthetic efficacy of different concentrations of MS-222 was compared to benzocaine and pentobarbital on the physiological changes, heart rate and ECG (electrocardiogram) parameters in the leopard frog, Rana pipiens. Loss of righting reflex (RR), loss of pain response (NR = nociceptor response) and recovery time were measured. Heart rate and ECG parameters were also tested before and during anesthesia. The time to loss of RR and NR decreased while recovery time markedly increased with the increasing concentration of MS-222. Benzocaine at 200 mg/l induced a rapid anesthesia, but all frogs needed resuscitation. Pentobarbital at 300 mg/l induced a slow anesthesia, however, all of the frogs also needed resuscitation. All anesthetics at the mentioned concentrations decreased heart rate significantly as well as altered the ECG parameters. All anesthetics prolonged the Q-T interval, and MS-222 at 800 mg/l and benzocaine at 200 mg/l were the most effective anesthetic concentrations in increasing the Q-T interval. Frogs anesthetized by benzocaine and pentobarbital and high concentrations of MS-222 required resuscitation due to hypoxia. Pentobarbital and benzocaine seem to be very effective compounds, but their safety margins are narrow because of ventilatory failure. Therefore, MS-222 at a concentration of 200 mg/l or less is highly recommended for leopard frogs because prolonged recovery, high mortality rate and significant ECG changes are observed with higher concentrations of MS-222.
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Aminobenzoatos , Anestésicos , Benzocaína , Hipnóticos e Sedativos , Pentobarbital , Aminobenzoatos/efeitos adversos , Período de Recuperação da Anestesia , Anestésicos/efeitos adversos , Animais , Benzocaína/efeitos adversos , Relação Dose-Resposta a Droga , Interações Medicamentosas , Eletrocardiografia , Frequência Cardíaca/efeitos dos fármacos , Hipnóticos e Sedativos/efeitos adversos , Nociceptores/efeitos dos fármacos , Nociceptores/fisiologia , Pentobarbital/efeitos adversos , Rana pipiensRESUMO
Cardiovascular disease development is significantly influenced by the effects of reactive species (RS). By virtue of their controlled production, regulation, and reactive nature, RS play important roles in the modulation of cellular signaling, growth, and death in the vasculature. Concentration gradients are important in determining the effects of RS. Low to moderate concentrations of RS act as mediators in signaling cascades and gene regulation, whereas high levels of RS cause cellular damage and death. Because a dual redox regulation state seems to exist in several signaling cascades, e.g., RS often induce upstream initiating events, whereas downstream events are reliant on reductive processes, alterations in cellular redox states influence the activation/inactivation of signaling events and transcription factors. In this review, the relationships between RS, specific signal transduction pathways, and aspects of cell-cycle control are discussed.
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Proteínas Quinases Ativadas por Mitógeno/metabolismo , Espécies Reativas de Nitrogênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Animais , Apoptose , Ciclo Celular , HumanosRESUMO
BACKGROUND: Previous research has indicated that at various organ sites there is a subset of adenocarcinomas that is regulated by beta-adrenergic and arachidonic acid-mediated signal transduction pathways. We wished to determine if this regulation exists in breast adenocarcinomas. Expression of mRNA that encodes a G-protein coupled inwardly rectifying potassium channel (GIRK1) has been shown in tissue samples from approximately 40% of primary human breast cancers. Previously, GIRK channels have been associated with beta-adrenergic signaling. METHODS: Breast cancer cell lines were screened for GIRK channels by RT-PCR. Cell cultures of breast cancer cells were treated with beta-adrenergic agonists and antagonists, and changes in gene expression were determined by both relative competitive and real time PCR. Potassium flux was determined by flow cytometry and cell signaling was determined by western blotting. RESULTS: Breast cancer cell lines MCF-7, MDA-MB-361 MDA-MB 453, and ZR-75-1 expressed mRNA for the GIRK1 channel, while MDA-MB-468 and MDA-MB-435S did not. GIRK4 was expressed in all six breast cancer cell lines, and GIRK2 was expressed in all but ZR-75-1 and MDA-MB-435. Exposure of MDA-MB-453 cells for 6 days to the beta-blocker propranolol (1 microM) increased the GIRK1 mRNA levels and decreased beta2-adrenergic mRNA levels, while treatment for 30 minutes daily for 7 days had no effect. Exposure to a beta-adrenergic agonist and antagonist for 24 hours had no effect on gene expression. The beta adrenergic agonist, formoterol hemifumarate, led to increases in K+ flux into MDA-MB-453 cells, and this increase was inhibited by the GIRK channel inhibitor clozapine. The tobacco carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a high affinity agonist for beta-adrenergic receptors stimulated activation of Erk 1/2 in MDA-MB-453 cells. CONCLUSIONS: Our data suggests beta-adrenergic receptors and GIRK channels may play a role in breast cancer.