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[en] Measurements of the incident dose on the eye have been taken during the tomographic examinations of the middle ear. These measurements have been effectuated without any protection of the eye, and with a Pb-diagram protection, thickness 2mm. The tomograph which has been used is an Italian one (Eurostrator-Zuder, Genoa) provided with complex radiation movements (circular, spiral) and which gives technical results such as the Polytom (generally used for these researches) but which has a focus-film distance of 1m instead of 1.40m. The average incident dose on the crystalline lens is high (11.7R); the use of the Pb-diaphragm reduces the dose considerably (0.65R) without any significant imperfections on the radiological image
[fr]Des mesures de la dose incidente recue par l'oeil ont ete faites au cours des examens tomographiques de l'oreille moyenne. Ces mesures ont ete effectuees sans aucune protection de l'oeil, puis avec protection d'un diaphragme de plomb, epais de 2mm. Le tomographe utilise est un appareil italien (Eurostrator-Zuder, Genes) doue de mouvements d'effacement complexes (circulaires et spirales), qui donne des resultats equivalents a ceux du polytome, generalement employe dans ces recherches, mais a une distance foyer-film de 1m au lieu de 1,40m. On a constate que la dose moyenne incidente sur le cristallin est elevee (11,7R), mais que l'utilisation du diaphragme de Pb la reduit sensiblement (0,65R), sans imperfections significatives de l'image radiologique
[en] Positron emitters may contribute considerably to the radiation from induced radioactivity in accelerator environments. In most cases of thick radiating objects (magnets, shielding walls) the dose rate from gamma emitters, including the 511 keV annihilation photons from positron emitters, dominates the radiation field. Direct positron interaction in skin tissue and in the lens of the eye may be an important contribution to absorbed dose in cases of thin targets and beam separating septa. Results of calculations and measurements show, however, that the dose to the lens of the eye is limited by limitations placed on whole-body doses. Irradiation from positron emitters gives rise to about the same absorbed doses as those experienced in the case of an electron exposure. (author)
[en] Purpose: To apply surface collimation for superficial flap HDR skin brachytherapy utilizing common clinical resources and to demonstrate the potential for OAR dose reduction within a clinically relevant setting. Methods: Two phantom setups were used. 3 mm lead collimation was applied to a solid slab phantom to determine appropriate geometries relating to collimation and dwell activation. The same collimation was applied to the temple of an anthropomorphic head phantom to demonstrate lens dose reduction. Each setup was simulated and planned to deliver 400 cGy to a 3 cm circular target to 3 mm depth. The control and collimated irradiations were sequentially measured using calibrated radiochromic films. Results: Collimation for the slab phantom attenuated the dose beyond the collimator opening, decreasing the fall-off distances by half and reducing the area of healthy skin irradiated. Target coverage can be negatively impacted by a tight collimation margin, with the required margin approximated by the primary beam geometric penumbra. Surface collimation applied to the head phantom similarly attenuated the surrounding normal tissue dose while reducing the lens dose from 84 to 68 cGy. To ensure consistent setup between simulation and treatment, additional QA was performed including collimator markup, accounting for collimator placement uncertainties, standoff distance verification, and in vivo dosimetry. Conclusions: Surface collimation was shown to reduce normal tissue dose without compromising target coverage. Lens dose reduction was demonstrated on an anthropomorphic phantom within a clinical setting. Additional QA is proposed to ensure treatment fidelity.
[en] Objective: To evaluate the effects of prolonged use of anastrozole as an endocrine treatment of breast cancer on the corneal epithelium in an animal model. Study Design: Laboratory based randomized control trial. Place and Duration of Study: Department of Anatomy, Army Medical College, Rawalpindi in collaboration with National Institute of Health, Islamabad, six months from Jun 2012 to Nov 2012. Material and Methods: Twenty adult female NewZealand white rabbits were taken. Ten rabbits were placed in control group taking normal diet and 10 were given anastrozole orally in the normal dose of 1 mg/day (0.02 mg/kg/day). After the completion of the study, corneas were removed and grossly examined. The specimen were fixed and slides prepared for histomorphological examination. The epithelium in each slide was examined for any deposits, edema or increase in stratification and the height of the epithelium was measured for each eye. The results were compared between the groups for statistical significance. Results: The epithelium had normal shape with no areas of any deposits, edema or ulceration. The mean epithelial height in the control group was 21.25 +- 4.29 mu m and 21.00 +- 4.28 mu m in the right corneas and left corneas, respectively. The mean epithelial height taken from the experimental group was 20.50 +- 4.97 mu m and 21.00 +- 4.28 mu m in right sided and left sided corneas, respectively. The p value was calculated to be 0.722 and 1.00 for the right and left corneas, respectively and no statistical significance was found in between the two groups. Conclusion: Long term administration of anastrozole has no effect on the histological morphology of the corneal epithelium. (author)
[en] The authors used 23Na NMR spectroscopy to investigate the intralenticular sodium resonance and the transmembrane fluxes in intact crystalline lenses incubated in TC-Earle culture medium. The preliminary results of a 23Na NMR study on human lenses taken from patients with cataract are reported. The paramagnetic shift reagent Dy(PPP)27- was used to distinguish the resonances from intra- and extracellular 23Na+. (Auth.)
[en] Shrinkage and whitening of the anterior capsule opening - capsular contraction syndrome - is a well-known complication after continuous curvilinear capsulorrhexis. A 72-year-old women underwent continuous curvilinear capsulorrhexis, phacoemulsification, and implantation of posterior chamber intraocular lens with polymethylmethacrylate haptics. Four months postoperatively, the patient reported deterioration in visual acuity that was resulted due to complete occlusion of anterior capsular opening by fibrotic tissue. The fibrous membrane was excised surgically in capsulorrhexis fashion. (author)
[en] Purpose: To study the findings and the diagnostic value of CT in traumatic cataract. Materials and methods: Out of 75 patients with orbital trauma, 55 cataractous lens were confirmed by clinical observations and operations. The CT appearances of cataract lens were analyzed and compared with the contralateral normal lens. Results: The lens density of the injured eye without traumatic cataract was similar to that of the contralateral normal lens. In 83.6%(46/55) of traumatic cataractous lens, the density was lower than that of the contralateral normal lens and the lens density of 17 was similar to that of the vitreous body. The decrease of lens density was related to the course of disease and the degree of damage, but not related to the cause of trauma, the coincidence rate of the CT and clinical diagnoses was 83.6%. The false negative rate was 16.4%. Conclusion: Decreased density of the injured lens is suggestive of formation of traumatic cataract
[en] Background: Age-related cataract is among the most common chronic disorders of ageing and the apoptosis of lens epithelial cells contributes to non-congenital cataract development. We amid to explore the role of TUG1 and miR-421 in the age-related cataract. Methods: The expression level of TUG1, miR-421 and caspase-3 were detected by RT-qPCR. The apoptotic-related protein, caspase-3, Bax and blc-2 were analyzed by western blot. We performed ultraviolet (UV) irradiation to induce SAR01/04 cell apoptosis which was analyzed by flow cytometry. RIP pull-down and luciferase reporter assay were used to verified the combination and regulating among TUG1, miR-421 and caspase-3. Results: Here, we observed that the expression level of TUG1 and caspase-3 in the anterior lens capsules of age-related cataract were significantly higher and miR-421 was significantly lower than that in the normal anterior lens capsules. The apoptosis-related protein, caspase-3, Bax and blc-2 were abnormal expression in the anterior lens capsules of age-related cataract tissue. Our data showed that the expression level of TUG1 and caspase-3 and cell apoptosis rate in SAR01/04 cells treated with UV irradiation was remarkably higher than that in the control. TUG1 negatively regulated miR-421 expression and promoted UV irradiation-induced SAR01/04 cell apoptosis. However, miR-421 inhibitor and pcDNA-caspase-3 could reverse the action of the SRA01/04 cell apoptosis by si-TUG1, which suggested TUG1 promoted UV irradiation-induced apoptosis through downregulating miR-421 expression. Furthermore, this study confirmed TUG1 could been in combination with miR-421, and TUG1 and caspase-3 were both a directly target of miR-421. Conclusion: TUG1 modulated lens epithelial cell apoptosis through miR-421/caspase-3 axis. These findings will offer a novel insight into the pathogenesis of cataract. - Highlights: • TUG1 is increased in age-related cataract and UV irradiation-induced SAR01/04 cell. • Highly expressed TUG1 promotes UV irradiation-induced SAR01/04 cell apoptosis. • TUG1 and caspase-3 are both a direct target of miR-421. • MiR-421 inhibitor increases si-TUG1-inhibited SAR01/04 cells apoptosis.