RESUMO
PURPOSES: The aim of this study is to investigate the time evolution of active caspase 3 within first 120 h in the rat lens after in vivo exposure to subthreshold dose of UVR-B. METHODS: Twenty three six-week-old female albino Sprague-Dawley rats were exposed to subthreshold dose (1 kJ/m2) of UVR-B unilaterally and sacrificed at 24, 41, 70 and 120 h after exposure. Lenses were enucleated and active caspase 3 was detected by Western Blot. The time evolution of active caspase 3 was then plotted as a function of relative mean difference in active caspase 3 between exposed and nonexposed lenses. RESULTS: There is expression of active caspase 3 in both exposed and nonexposed lenses but there is no difference in relative mean difference in active caspase 3 between exposed and nonexposed lenses in all four postexposure groups. CONCLUSIONS: Exposure to subthreshold dose of UVR-B does not induce apoptosis in the rat lens in vivo within first 120 h though there is a non-significant increase of active caspase 3 at 120 h. Increase in sample size might reduce the variation level in expression of active caspase 3 in the rat lenses.
Assuntos
Caspase 3 , Cristalino , Raios Ultravioleta , Animais , Feminino , Ratos , Apoptose , Western Blotting , Caspase 3/metabolismo , Caspase 3/efeitos da radiação , Cristalino/metabolismo , Cristalino/efeitos da radiação , Ratos Sprague-DawleyRESUMO
BACKGROUND Competing risk analysis determines the probability of survival and considers competing events. This retrospective study aimed to undertake a competing risk analysis of prognosis in patients with esophageal carcinoma between 2006-2015 using data from the Surveillance, Epidemiology, and End Results (SEER) database. MATERIAL AND METHODS Clinicopathological, demographic, and survival data were analyzed for patients with esophageal carcinoma registered in the SEER database between 2006-2015. The competing risk model calculated the cumulative incidence function (CIF) of events of interest and prognosis. The Cox proportional-hazards model and the cause-specific hazard function (CS) were used to generalize the hazard function for competing risks. The Fine-Gray model was used for multivariate analysis. More accurate prognostic factors were analyzed by comparing the hazard ratio (HR) values between groups. RESULTS There were 14,695 patients identified with esophageal carcinoma, 9,621 died from esophageal carcinoma, and 1,251 patients died from other causes. The cumulative incidence of events of interest was significant for age at diagnosis, race, primary tumor site, grade, stage, and treatment with surgery, radiotherapy, and chemotherapy (P<0.001). Multivariate analysis showed that age at diagnosis, primary tumor site, grade, stage, and treatment with surgery, radiotherapy, and chemotherapy statuses were independent prognostic factors (P<0.05). The Fine-Gray and the CS model showed that grade, stage, and treatments with surgery, radiotherapy, and chemotherapy were significant independent prognostic factors (P<0.05). CONCLUSIONS A competing risk model used data from the SEER database to obtain a more accurate estimate of the CIF of esophageal carcinoma-specific mortality and prognostic factors.
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Neoplasias Esofágicas/epidemiologia , Neoplasias Esofágicas/mortalidade , Medição de Risco/métodos , Adulto , Idoso , Causas de Morte , Bases de Dados Factuais , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Nomogramas , Probabilidade , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de Risco , Programa de SEERRESUMO
Visual quantification and classification of fluorescent signals is the gold standard in microscopy. The purpose of this study was to develop an automated method to delineate cells and to quantify expression of fluorescent signal of biomarkers in each nucleus and cytoplasm of lens epithelial cells in a histological section. A region of interest representing the lens epithelium was manually demarcated in each input image. Thereafter, individual cell nuclei within the region of interest were automatically delineated based on watershed segmentation and thresholding with an algorithm developed in Matlab™. Fluorescence signal was quantified within nuclei, cytoplasms and juxtaposed backgrounds. The classification of cells as labelled or not labelled was based on comparison of the fluorescence signal within cells with local background. The classification rule was thereafter optimized as compared with visual classification of a limited dataset. The performance of the automated classification was evaluated by asking 11 independent blinded observers to classify all cells (n = 395) in one lens image. Time consumed by the automatic algorithm and visual classification of cells was recorded. On an average, 77% of the cells were correctly classified as compared with the majority vote of the visual observers. The average agreement among visual observers was 83%. However, variation among visual observers was high, and agreement between two visual observers was as low as 71% in the worst case. Automated classification was on average 10 times faster than visual scoring. The presented method enables objective and fast detection of lens epithelial cells and quantification of expression of fluorescent signal with an accuracy comparable with the variability among visual observers. © 2017 International Society for Advancement of Cytometry.
Assuntos
Cristalino/metabolismo , Algoritmos , Animais , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Células Epiteliais/metabolismo , Fluorescência , Ratos , Ratos Sprague-DawleyRESUMO
The aim of the present study was to examine if topically applied caffeine influences pupil size in ketamine/xylazine anesthetized animals. Two experiments were carried out. In the first experiment, caffeine was topically applied to one of the eyes of 10 ketamine/xylazine anesthetized animals, while vehicle only was topically applied to the contralateral eye. In the second experiment, caffeine was topically applied to both eyes in one group of 10 ketamine/xylazine anesthetized rats, while in another group both eyes vehicle only was topically applied to both eyes. In both experiments pupil diameter was measured at 0, 10, 20, 40 and 60 min after topical application. In three of the animals, the pupil was dilated with tropicamide 5 mg/ml at 60 min after the topical application of caffeine and the pupil diameter was measured. The first experiment showed a relative miosis in caffeine treated eyes as compared to the vehicle treated eye, that changed over time. The second experiment in line with the first experiment, also showed that topically applied caffeine causes a relative miosis as compared to vehicle only that changes over time. Eyes treated with caffeine reacted with quick dilatation after tropicamide application. Topical caffeine antagonizes ketamine/xylazine anesthesia induced mydriasis in a time dependent manner.
Assuntos
Anestésicos Combinados/administração & dosagem , Cafeína/administração & dosagem , Estimulantes do Sistema Nervoso Central/administração & dosagem , Ketamina/administração & dosagem , Miose/induzido quimicamente , Pupila/efeitos dos fármacos , Xilazina/administração & dosagem , Administração Tópica , Agonistas de Receptores Adrenérgicos alfa 2/administração & dosagem , Animais , Antagonistas de Aminoácidos Excitatórios/administração & dosagem , Injeções Intraperitoneais , Ratos , Ratos Sprague-DawleyRESUMO
Topically applied caffeine was recently identified as a promising candidate molecule for cataract prevention. Little is known about the pharmacokinetics for topically applied caffeine. Potential toxicity of 72 mM caffeine on the ocular surface and the lens was qualitatively monitored and no toxic effects were observed. The concentration of caffeine was measured in the lens and the blood after topical application of 72 mM caffeine to groups of 10 animals sacrificed at 30, 60, 90 and 120 min after topical application. The lens concentration decreased throughout the observation period while the blood concentration increased up to 120 min. Further, the concentration of caffeine in the lens and blood was measured 30 min after topical application of caffeine, the concentration of caffeine being 0.72, 3.34, 15.51 and 72 mM depending on group belonging, in groups of 10 animals. The caffeine concentration in lens and blood, respectively, increased proportionally to the caffeine concentration topically applied. The rat blood concentrations achieved were far below the equivalent threshold dose of FDA recommended daily dose for humans. This information is important for further development of caffeine eye drops for cataract prevention.
Assuntos
Humor Aquoso/metabolismo , Cafeína/farmacocinética , Estimulantes do Sistema Nervoso Central/farmacocinética , Córnea/metabolismo , Cristalino/metabolismo , Administração Tópica , Animais , Cromatografia Líquida de Alta Pressão , Soluções Oftálmicas , Ratos , Ratos Sprague-Dawley , Distribuição TecidualRESUMO
PURPOSE: Glaucoma leads to pathological loss of axons in the retinal nerve fibre layer at the optic nerve head (ONH). This study aimed to develop a strategy for the estimation of the cross-sectional area of the axons in the ONH. Furthermore, improving the estimation of the thickness of the nerve fibre layer, as compared to a method previously published by us. METHODS: In the 3D-OCT image of the ONH, the central limit of the pigment epithelium and the inner limit of the retina, respectively, were identified with deep learning algorithms. The minimal distance was estimated at equidistant angles around the circumference of the ONH. The cross-sectional area was estimated by the computational algorithm. The computational algorithm was applied on 16 non-glaucomatous subjects. RESULTS: The mean cross-sectional area of the waist of the nerve fibre layer in the ONH was 1.97 ± 0.19 mm2 . The mean difference in minimal thickness of the waist of the nerve fibre layer between our previous and the current strategies was estimated as CIµ (0.95) 0 ± 1 µm (d.f. = 15). CONCLUSIONS: The developed algorithm demonstrated an undulating cross-sectional area of the nerve fibre layer at the ONH. Compared to studies using radial scans, our algorithm resulted in slightly higher values for cross-sectional area, taking the undulations of the nerve fibre layer at the ONH into account. The new algorithm for estimation of the thickness of the waist of the nerve fibre layer in the ONH yielded estimates of the same order as our previous algorithm.
Assuntos
Glaucoma , Disco Óptico , Humanos , Disco Óptico/diagnóstico por imagem , Disco Óptico/patologia , Células Ganglionares da Retina/patologia , Fibras Nervosas/patologia , Tomografia de Coerência Óptica/métodosRESUMO
The purpose of this study was to investigate if topically applied caffeine protects against in vivo ultraviolet radiation cataract and if so, to estimate the protection factor. Three experiments were carried out. First, two groups of Sprague-Dawley rats were pre-treated with a single application of either placebo or caffeine eye drops in both eyes. All animals were then unilaterally exposed in vivo to 8 kJ/m(2) UV-B radiation for 15 min. One week later, the lens GSH levels were measured and the degree of cataract was quantified by measurement of in vitro lens light scattering. In the second experiment, placebo and caffeine pre-treated rats were divided in five UV-B radiation dose groups, receiving 0.0, 2.6, 3.7, 4.5 or 5.2 kJ/m(2) UV-B radiation in one eye. Lens light scattering was determined after one week. In the third experiment, placebo and caffeine pre-treated rats were UV-B-exposed and the presence of activated caspase-3 was visualized by immunohistochemistry. There was significantly less UV-B radiation cataract in the caffeine group than in the placebo group (95% confidence interval for mean difference in lens light scattering between the groups = 0.10 ± 0.05 tEDC), and the protection factor for caffeine was 1.23. There was no difference in GSH levels between the placebo- and the caffeine group. There was more caspase-3 staining in UV-B-exposed lenses from the placebo group than in UV-B-exposed lenses from the caffeine group. Topically applied caffeine protects against ultraviolet radiation cataract, reducing lens sensitivity 1.23 times.
Assuntos
Cafeína/administração & dosagem , Catarata/prevenção & controle , Estimulantes do Sistema Nervoso Central/administração & dosagem , Cristalino/efeitos da radiação , Lesões Experimentais por Radiação/prevenção & controle , Raios Ultravioleta/efeitos adversos , Administração Tópica , Animais , Caspase 3/metabolismo , Catarata/diagnóstico , Catarata/metabolismo , Técnica Indireta de Fluorescência para Anticorpo , Glutationa/metabolismo , Cristalino/metabolismo , Cristalino/patologia , Masculino , Soluções Oftálmicas , Doses de Radiação , Lesões Experimentais por Radiação/diagnóstico , Lesões Experimentais por Radiação/metabolismo , Ratos , Ratos Sprague-Dawley , Espalhamento de RadiaçãoRESUMO
PURPOSE: To estimate the sources of variation for Pigment epithelium central limit-Inner limit of the retina Minimal Distance averaged over 2π (PIMD-2π), and further to analyse their consequences for clinical measurements of glaucoma. METHODS: Forty subjects with early to moderate stage glaucoma were included. Three SD-OCT volumes of the optic nerve head (ONH) were captured at two occasions. Each volume was segmented three times for PIMD-2π. The magnitude of the sources of variation for PIMD-2π measurements was estimated with an analysis of variance. RESULTS: A 95% confidence interval for mean PIMD-2π was estimated to 215 ± 12 µm (df = 38). The estimated variance for subjects was 1280 µm2 . The within-subject estimated variance for occasions, volumes and segmentations was 10 µm2 , 30 µm2 and 40 µm2 , respectively. The within-subject variances were used to model follow-up of PIMD-2π over time. A linear loss rate of 0.05 of baseline PIMD-2π/year was assumed. A significant PIMD-2π change could be detected in approximately 16-18 months with evenly spaced visits every 4 or 6 months. CONCLUSIONS: Due to the small within-subject estimated variances, a clinically undesirable PIMD-2π change from baseline can be detected in approximately 18 months. Detection of significant PIMD-2π loss in a subject requires knowledge of normal age loss and measurement variability.
Assuntos
Glaucoma de Ângulo Aberto/diagnóstico , Fibras Nervosas/patologia , Disco Óptico/patologia , Doenças do Nervo Óptico/diagnóstico , Células Ganglionares da Retina/patologia , Idoso , Feminino , Glaucoma de Ângulo Aberto/fisiopatologia , Humanos , Pressão Intraocular/fisiologia , Masculino , Pessoa de Meia-Idade , Disco Óptico/diagnóstico por imagem , Doenças do Nervo Óptico/fisiopatologia , Estudos Prospectivos , Tomografia de Coerência Óptica , Campos Visuais/fisiologiaRESUMO
BACKGROUND: Our aim was to identify the independent prognostic factors in patients with primary urethral carcinoma (PUC) and to predict their overall survival (OS) and cancer-specific survival (CSS) at 3, 5, and 8 years. METHODS: Patients with PUC identified in the Surveillance, Epidemiology, and End Results (SEER) database were divided into training and validation cohorts. Nomograms were constructed based on the results of Cox regression analysis. The predictive performance of each nomogram was evaluated using the consistency index (C-index), the area under the receiver operating characteristics curve (AUC), and calibration plots. Decision-curve analysis (DCA) was used to test the clinical value of the predictive models. RESULTS: Our study screened 822 patients with PUC. Multivariate analysis showed that the age at diagnosis, race, histology, American Joint Committee on Cancer (AJCC) stage, and surgery status were independent prognostic factors for CSS and age at diagnosis, race, histology, AJCC stage, surgery status, and chemotherapy for OS (all P < 0.05). We used these prognostic factors to construct nomograms. The C-indexes for OS and CSS were 0.713 and 0.741 in training cohorts and 0.714 and 0.738 in validation cohorts, respectively. The AUC and calibration plots demonstrated the good performance of both nomograms. The DCA indicated the presence of clinical net benefits in both the training and validation cohorts. CONCLUSION: We developed and validated nomograms for predicting OS and CSS in patients with PUC, which can help clinicians make treatment decisions.
Assuntos
Adenocarcinoma/mortalidade , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células de Transição/mortalidade , Nomogramas , Neoplasias Uretrais/mortalidade , Adenocarcinoma/patologia , Adenocarcinoma/terapia , Negro ou Afro-Americano/estatística & dados numéricos , Fatores Etários , Idoso , Antineoplásicos/uso terapêutico , Área Sob a Curva , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/terapia , Carcinoma de Células de Transição/patologia , Carcinoma de Células de Transição/terapia , Feminino , Humanos , Masculino , Estadiamento de Neoplasias , Prognóstico , Modelos de Riscos Proporcionais , Curva ROC , Programa de SEER , Taxa de Sobrevida , Fatores de Tempo , Estados Unidos/epidemiologia , Neoplasias Uretrais/patologia , Neoplasias Uretrais/terapia , População Branca/estatística & dados numéricosRESUMO
The current study aims to experimentally estimate the temperature in the lens due to heat load indirectly from the measurement of increases in the rate of temperature-induced light scattering. The lens was extracted from SpragueDawley rats and put into a temperature-controlled cuvette filled with a balanced salt solution. Altogether, 80 lenses were equally divided into four temperature groups. Each lens was exposed for 5 min to temperature depending on the group to which it belonged while the intensity of forward light scattering was recorded. The inclination coefficients of light scattering increase at the temperature of 37°C, 40°C, 43°C, and 46°C were estimated as a CI(0.95), 3.1 ± 0.8 , 4.4 ± 0.8 , 5.5 ± 0.9 , and 7.0 ± 0.8 × 10 ? 4 ?? tEDC / s , respectively. The Arrhenius equation implies that the natural logarithm of the inclination coefficient is linearly dependent on the inverse of the temperature. The proportionality constant and the intercept were 9.6 ± 2.4 × 10 3 ?? K and 22.8 ± 7.7 , respectively. The activation energy was 8.0 ± 2.0 × 10 1 ?? kJ · mol ? 1 . The current experiment implies that if averaging 20 measurements of inclination coefficients in a new experiment at constant heat load, the confidence limits for predicted temperature correspond to ± 1.9°C. With the proportionality constant and the intercept estimated in the current experiment, the in vivo temperature in the lens can be determined retrospectively with sufficient resolution.
Assuntos
Temperatura Corporal/fisiologia , Cristalino/fisiologia , Luz , Espalhamento de Radiação , Animais , Temperatura Alta , Ratos , Ratos Sprague-DawleyRESUMO
PURPOSE: To estimate the variation in measurements of neuro-retinal rim area (NRA) determined by confocal scanning laser tomography and consequences for clinical follow-up. METHODS: Altogether, 24 healthy subjects were randomized on -320 µm, Moorfields and Standard NRA plane strategies. Additionally, NRA was measured in 32 glaucoma subjects. Variance components for subjects, visits and measurements were estimated with analysis of variance. Sample sizes required to detect a 6.0 × 10-2 mm2 NRA change were estimated assuming a significance level of 0.05 and a power of 0.8. Consequences for independent group, and paired comparison design, respectively, were analysed. Further, precision in estimates within subjects over time was investigated. RESULTS: The variation of NRA among subjects was considerably larger than the variation among visits and measurements. For glaucoma subjects, the variation among visits and measurements were of the same order but larger than in healthy subjects. It was found that independent group comparisons require inconveniently large sample sizes. Within-subject paired comparisons over time require sample sizes of below 15 subjects. The estimated variations for glaucoma subjects imply that 54 months of follow-up is required for detection of change from baseline. CONCLUSIONS: The variance for subjects is substantial in relation to those for visits and measurements. Cross-sectional independent group comparisons of levels of NRA are unsuitable, due to considerable subject variation. Levels of NRA differences within subjects between visits can be estimated with acceptable precision. Neuro-retinal rim area (NRA) measurement can be used for long-term follow-up of glaucoma progression.
Assuntos
Glaucoma/diagnóstico , Fibras Nervosas/patologia , Disco Óptico/patologia , Células Ganglionares da Retina/patologia , Polarimetria de Varredura a Laser/normas , Adulto , Idoso , Feminino , Seguimentos , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes , Estudos Retrospectivos , Tomografia/normasRESUMO
The damage mechanism for near-infrared radiation (IRR) induced cataract is unclear. Both a photochemical and a thermal mechanism were suggested. The current paper aims to elucidate a photochemical effect based on investigation of irradiance-exposure time reciprocity. Groups of 20 rats were unilaterally exposed to 96-W/cm(2) IRR at 1090 nm within the dilated pupil accumulating 57, 103, 198, and 344 kJ/cm(2), respectively. Temperature was recorded at the limbus of the exposed eye. Seven days after exposure, the lenses were macroscopically imaged and light scattering was quantitatively measured. The average maximum temperature increases for exposure times of 10, 18, 33, and 60 min were expressed as 7.0 ± 1.1, 6.8 ± 1.1, 7.6 ± 1.3, and 7.4 ± 1.1 °C [CI (0.95)] at the limbus of the exposed eye. The difference of light scattering in the lenses between exposed and contralateral not-exposed eyes was 0.00 ± 0.02, 0.01 ± 0.03, -0.01 ± 0.02, and -0.01 ± 0.03 transformed equivalent diazepam concentration (tEDC), respectively, and no apparent morphological changes in the lens were observed. An exposure to 96-W/cm(2) 1090-nm IRR projected on the cornea within the dilated pupil accumulating radiant exposures up to 344 kJ/cm(2) does not induce cataract if the temperature rise at the limbus is <8 °C. This is consistent with a thermal damage mechanism for IRR-induced cataract.
Assuntos
Catarata/etiologia , Temperatura Alta/efeitos adversos , Raios Infravermelhos/efeitos adversos , Cristalino/efeitos da radiação , Animais , Feminino , Luz , Ratos , Ratos Sprague-Dawley , Espalhamento de RadiaçãoRESUMO
PURPOSE: Peak toxicity for in vivo ultraviolet radiation (UVR) exposure to the lens is in the 300-nm wavelength region. However, little is known about corneal cell damage at 300 nm. The purpose of the study was to determine the time evolution of apoptosis in the cornea after in vivo exposure to 300-nm UVR. METHODS: Altogether, 16 Sprague Dawley rats were divided into 4 groups and unilaterally exposed to 5 kJ/m UVR (λmax: 300 nm; λ0.5: 10 nm) for 15 minutes. After a predetermined latency period of 1, 5, 24, and 120 hours, depending on the group, the animals were killed and eyes were enucleated. Eye globes were further cryosectioned in 10-µm thick midsagittal sections. For the detection of apoptosis, the TUNEL method was applied. RESULTS: TUNEL-positive signals were observed in the superficial epithelial cells in the exposed and control eyes at all latency periods. At 5 hours, TUNEL staining was detected in the exposed corneas in epithelial cells, keratocytes, and endothelial cells with a maximum signal at 24 hours. At 120 hours, no TUNEL staining was found in endothelial cells and only occasionally in keratocytes in exposed corneas. Signs of ulceration and stromal thinning were observed at 120 hours. CONCLUSIONS: UVR in the 300-nm wavelength region induces TUNEL staining in all 3 corneal layers. TUNEL staining of all 3 corneal layers is an early postexposure event observed after a 5-hour latency period. Corneal sterile keratolysis occurs in the time window of 24 to 120 hours probably induced by neutrophils.
Assuntos
Apoptose/efeitos da radiação , Córnea/efeitos da radiação , Doenças da Córnea/patologia , Lesões Experimentais por Radiação/patologia , Raios Ultravioleta/efeitos adversos , Animais , Córnea/patologia , Doenças da Córnea/etiologia , Ceratócitos da Córnea/patologia , Ceratócitos da Córnea/efeitos da radiação , Fragmentação do DNA/efeitos da radiação , Endotélio Corneano/patologia , Endotélio Corneano/efeitos da radiação , Epitélio Corneano/patologia , Epitélio Corneano/efeitos da radiação , Feminino , Marcação In Situ das Extremidades Cortadas , Microscopia de Fluorescência , Lesões Experimentais por Radiação/etiologia , Ratos , Ratos Sprague-DawleyRESUMO
PURPOSE: To determine the distribution of active caspase-3 in rat eye lens epithelium. METHODS: In total, 120 sagittal sections from forty rats were assessed for active caspase-3 labelling using immunohistochemistry. Lens epithelial cells were counted, and the fraction of active caspase-3 labelled cells and their relative positions were identified in each section. RESULTS: Active caspase-3 is present in normal lens epithelium. The active caspase-3 expression was higher in the anterior pole of the lens. Probability of radial spatial distribution of labelling was fitted with a logistic model. The increase rate and the inflection point were estimated as CI (0.95) to 23 ± 3 cells and 114 ± 3 cells, respectively. CONCLUSION: The gradually decreasing active caspase-3 labelling from the anterior pole to the periphery suggests that active caspase-3 may be involved in normal protein turnover caused by, for example, incident light.
Assuntos
Caspase 3/metabolismo , Cristalino/enzimologia , Animais , Células Epiteliais/enzimologia , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Cristalino/citologia , Ratos , Ratos Sprague-DawleyRESUMO
PURPOSE: To investigate whether infrared radiation (IRR)-induced cataract is instant or is associated with a time delay between the exposure and the onset of lens light scattering after an exposure to just above threshold dose. METHODS: Six-weeks-old albino Sprague-Dawley female rats were unilaterally exposed to 197 W/cm2 IRR at 1090 nm within the dilated pupil. In the first experiment, the animals were exposed with four exposure times of 5, 8, 13 and 20 second, respectively. At 24 hr after exposure, the light scattering in both exposed and contralateral not exposed lenses was measured. Based on the first experiment, four postexposure time groups were exposed unilaterally to 1090 nm IRR of 197 W/cm2 for 8 second. At 6, 18, 55 and 168 hr after exposure, the light scattering in both lenses was measured. RESULTS: A 197 W/cm2 IRR-induced light scattering in the lens with exposures of at least 8 second. Further, after exposure to IRR of 197 W/cm2 for 8 second, the light-scattering increase in the lens was delayed approximately 16 hr after the exposure. CONCLUSION: There is a time delay between the exposure and the onset of cataract after exposure to close to threshold dose implicating that either near IRR cataract is photochemical or there is a time delay in the biological expression of thermally induced damage.
Assuntos
Catarata/etiologia , Raios Infravermelhos/efeitos adversos , Cristalino/efeitos da radiação , Lesões Experimentais por Radiação/etiologia , Animais , Catarata/patologia , Relação Dose-Resposta à Radiação , Feminino , Doses de Radiação , Lesões Experimentais por Radiação/patologia , Ratos , Ratos Sprague-Dawley , Espalhamento de Radiação , Fatores de TempoRESUMO
PURPOSE: To introduce a model for the time evolution of active caspase-3 protein expression in albino rat lens up to 24 hours after in vivo exposure to low dose UVR in the 300 nm wavelength region (UVR-300 nm). METHODS: Forty Sprague-Dawley rats were unilaterally exposed in vivo to 1 kJ/m2 UVR-300 nm for 15 minutes. At 0.5, 8, 16, and 24 hours after the UVR exposure, the exposed and contralateral not-exposed lenses were removed and processed for immunohistochemistry. The differences in the probability of active caspase-3 expression at four different time points after exposure were used to determine the time evolution of active caspase-3 expression. A logistic model was introduced for the expression of active caspase-3. The parameters for the exposed and the not exposed lenses were estimated for the observation time points. RESULTS: The exposure to UVR-300 nm impacted on the parameters of the logistic model. Further, the parameters of the model varied with time after exposure to UVR-300 nm. CONCLUSION: The logistic model predicts the impact of exposure to UVR-300 nm on the spatial distribution of probability of active caspase-3 protein expression, depending on time.
Assuntos
Caspase 3/metabolismo , Cristalino/efeitos da radiação , Lesões Experimentais por Radiação/metabolismo , Raios Ultravioleta , Animais , Cristalino/metabolismo , Modelos Teóricos , Ratos , Ratos Sprague-Dawley , Fatores de TempoRESUMO
PURPOSE: To determine the time evolution of active caspase-3 protein expression in albino rat lens after in vivo exposure to low-dose UVR-300 nm, as detected by immunofluorescence. METHODS: Forty Sprague-Dawley rats were unilaterally exposed in vivo to 1 kJ/m(2) UVR-300 nm for 15 min. At 0.5, 8, 16 and 24 hr after the UVR exposure, the exposed and contralateral nonexposed lenses were removed and processed for immunohistochemistry. Three mid-sagittal sections from each lens were stained. The cells labelled for active caspase-3 in each section of both the exposed and nonexposed lenses were counted and recorded three times. The difference of the proportion of labelling between the exposed and contralateral nonexposed lenses within each animal was calculated. The differences of active caspase-3 labelling at four different time-points after exposure were used to determine the time evolution of active caspase-3 expression. RESULTS: Caspase-3 expression was higher in the exposed than in contralateral nonexposed lenses. The mean difference between the exposed and contralateral nonexposed lenses, including all lenses from all time intervals, was 0.12 ± 0.01 (= CI 95%). The mean differences between the exposed and contralateral nonexposed lenses were 0.11 ± 0.02, 0.13 ± 0.02, 0.14 ± 0.01 and 0.09 ± 0.03 (= CI 95%) for the 0.5-, 8-, 16- and 24-hr time groups, respectively. The orthogonal comparison showed no difference in the expression of active caspase-3 between the 0.5- and the 24-hr groups (Test statistic 1.50, F1,36 = 4.11, p < 0.05) or between the 8- and the 16-hr groups (test statistic 0.05, F1,36 = 4.11, p < 0.05). There was a difference when comparing the 0.5- and 24-hr groups to the 8- and 16-hr groups (test statistic 7.01, F1,36 = 4.11, p < 0.05). CONCLUSION: The expression of active caspase-3 in the lens epithelium increases after UVR exposure. There is a peak of expression approximately 16 hr after the exposure.
Assuntos
Caspase 3/metabolismo , Cristalino/efeitos da radiação , Lesões Experimentais por Radiação/enzimologia , Raios Ultravioleta/efeitos adversos , Animais , Feminino , Imuno-Histoquímica , Cristalino/enzimologia , Ratos , Ratos Sprague-Dawley , Fatores de TempoRESUMO
An in vivo exposure to 197 W/cm 2 1090-nm infrared radiation (IRR) requires a minimum 8 s for cataract induction. The present study aims to determine the ocular temperature evolution and the associated heat flow at the same exposure conditions. Two groups of 12 rats were unilaterally exposed within the dilated pupil with a close to collimated beam between lens and retina. Temperature was recorded with thermocouples. Within 5 min after exposure, the lens light scattering was measured. In one group, the temperature rise in the exposed eye, expressed as a confidence interval (0.95), was 11±3°C at the limbus, 16±6°C in the vitreous behind lens, and 16±7°C on the sclera next to the optic nerve, respectively. In the other group, the temperature rise in the exposed eye was 9±1°C at the limbus and 26±11°C on the sclera next to the optic nerve, respectively. The difference of forward light scattering between exposed and contralateral not exposed eye was 0.01±0.09 tEDC. An exposure to 197 W/cm 2 1090-nm IRR for 8 s induces a temperature increase of 10°C at the limbus and 26°C close to the retina. IRR cataract is probably of thermal origin.
Assuntos
Temperatura Corporal/efeitos da radiação , Raios Infravermelhos , Cristalino/efeitos da radiação , Fenômenos Fisiológicos Oculares/efeitos da radiação , Termodinâmica , Animais , Feminino , Luz , Ratos , Ratos Sprague-Dawley , Espalhamento de RadiaçãoRESUMO
PURPOSE/AIM: To quantitatively analyse the evolution of TUNEL-labeling, after in vivo exposure to UVB. METHODS: Altogether, 16 Sprague Dawley rats were unilaterally exposed in vivo for 15 min to close to threshold dose, 5 kJ/m(2), of ultraviolet radiation in the 300 nm wavelength region. Animals were sacrificed in groups of 4 at 1, 5, 24 and 120 h after exposure. For each animal, both eye globes were removed and frozen. The frozen eye was cryo-sectioned in 10 µm thick midsagittal sections. From each globe, three midsagittal sections with at least five sections interval in between were mounted on a microscope slide. Sections were TUNEL-labeled and counter stained with DAPI. For quantification of apoptosis, a fluorescence microscope was used. In sections with a continuous epithelial cell surface, the number of lens epithelial cell nuclei and the number of TUNEL-positive epithelial cell nuclei was counted. The total number of TUNEL-positive epithelial cell nuclei for all three sections of one lens in relation to the total number of epithelial cell nuclei for all three sections of the same lens was compared between exposed and contralateral not exposed lens for each animal. RESULTS: The relative difference of the fraction of TUNEL-positive nuclei between exposed and contralateral not exposed lens increased gradually, peaked in the time interval 5-120 h after exposure, and then declined. CONCLUSIONS: Close to threshold dose of UVB induces TUNEL-labeling that peaks in the time window 5-120 h after exposure to UVB.
Assuntos
Catarata/patologia , Marcação In Situ das Extremidades Cortadas/métodos , Cristalino/patologia , Cristalino/efeitos da radiação , Lesões Experimentais por Radiação/patologia , Raios Ultravioleta/efeitos adversos , Animais , Apoptose , Feminino , Doses de Radiação , Ratos , Ratos Sprague-DawleyRESUMO
BACKGROUND AND OBJECTIVE: Interleukin (IL)-10 is a pleiotropic cytokine that can both stimulate and suppress the immune response. Previous studies have reported that IL-10 production was significantly elevated in cachectic patients, and it has been confirmed that polymorphisms of the IL10 gene could influence its expression. Therefore, we designed this study to investigate whether polymorphisms of the IL10 gene were associated with cachexia in patients with low-third gastric cancer in a Chinese population. METHODS: 190 patients with low-third gastric cancer were included in this study. The serum levels of IL-10 were measured by radioimmunoassay. The single nucleotide polymorphisms (SNPs) at positions -1082A/G, -819T/C, and -592A/C in the IL10 gene promoter were analyzed using polymerase chain reaction (PCR) restriction fragment length polymorphism (PCR-RFLP). RESULTS: The serum levels of IL-10 were significantly higher in patients with cachexia than in those without (Z = -10.66, p < 0.001). Single SNP analysis showed that the frequency of the IL10 -1082G allele was increased in patients with cachexia (p = 0.02). The -1082AG and -819CC genotypes were observed to be associated with an increased risk of cachexia. In a logistic regression analysis adjusted for actual weight and carcinoma stage, the -1082AG genotype was associated with an odds ratio (OR) of 2.45 (95% CI 1.21, 4.96; p = 0.01), and the -819CC genotype was associated with an OR of 3.70 (95% CI 1.20, 11.39; p = 0.02) for cachexia. Furthermore, haplotype analysis of the -1082A/G, -819T/C, and -592A/C SNPs revealed that at least five haplotypes (ATA, ACC, GCC, ACA, and ATC) were present in this Chinese population, and the -1082G/-819C/-592C (GCC) haplotype was associated with a significantly increased risk of cachexia as compared with the ATA haplotype (OR = 2.42; 95% CI 1.17, 5.00; p = 0.02). CONCLUSION: Our results indicate that genetic polymorphisms of IL-10 may influence susceptibility to cachexia in patients with low-third gastric cancer in this Chinese population.