复方中药青光安对兔慢性高眼压筛板结构及Ⅳ型胶原纤维含量的影响

目的:探讨复方中药青光安混悬液对慢性高眼压兔筛板结构及功能的影响。方法:健康白兔30只,体质量2.5～3.0kg,雌雄不拘。每组6只12眼,分为5组,A为正常空白组、B为模型组、C为青光安组、D为噻吗心安组、E为青光安联合噻吗心安组,建立慢性高眼压模型前、后第1wk内3d测1次眼压,2,5wk各测1次眼压。5wk处死家兔取视乳头及周围组织然后修剪得筛板组织,用免疫组化方法测Ⅳ型胶原纤维平均吸光度值,并在光镜及电镜下观察组织结构的变化。结果:40眼成功造模后当时;1,2,5wk眼压均>22mmHg。造模后5wk时各组眼压进行比较:青光安组眼压与模型组相比无明显差异(P>0.05),与其他治疗组及正常组相比有极显著差异(P<0.01);噻吗心安组与联合组眼压相比无明显差异,并且两组与正常组眼压相比亦无明显差异。造模后5wk正常组Ⅳ型胶原纤维平均吸光度值与联合组相比无显著差异,与其他3组相比有极显著差异(P<0.01);联合组与青光安组、噻吗心安组及模型组相比有极显著差异(P<0.01)。光镜、电镜结果表明,与模型组比较,治疗组巩膜筛板部纤维走向基本有序,无断裂、水肿,神经细胞胞质内线粒体大致正常,其中各组筛板结构病理改变程度由大到小依次为:噻吗心安组、青光安、联合治疗组。结论:青光安混悬液对慢性高眼压通过改善视网膜微循环起到筛板组织保护的作用,青光安联合噻吗心安明确降压后对筛板组织结构保护作用更为明显。     

Severity,therapeutic, and activity tear biomarkers in dry eye disease: An analysis from a phase III clinical trial

Purpose

To evaluate the effect of 0.1%-fluorometholone (FML) on tear inflammatory molecule levels after 22-days treatment in dry eye disease (DED) patients exposed to an adverse controlled environment (ACE), identifying different biomarkers.

Accommodation in human eye models: a comparison between the optical designs of Navarro, Arizona and Liou-Brennan

AIM: To simulate and compare accommodation in accommodative and non-accommodative human eye models. METHODS: Ray tracing and optical design program was used. Three eye models were designed and studied: the Navarro, the Arizona and the Liou-Brennan. In order to make the Navarro and Liou-Brennan models to accommodate, specific geometric parameters of the models were altered with values that were chosen from the literature. For the Arizona model, its’ mathematical functions for accommodation were used for the same accommodative demands. The simulation included four distances of accommodation for each model: at infinity, 3, 1 and 0.5 m.The results were diffraction images of a “letter F” for graphical comparison, spot diagrams on the retinal field and Modulation Transfer Function (MTF) graphs. RESULTS:Zernike coefficients for the aberrations, Airy disk diameter, root mean square (RMS) error diameter and total axial length of the model were provided from the program. These were compared between them in all distances. The Navarro model had the smallest axial length change as a simple model. The Arizona did not change its axial length because it is designed to be accommodative. The Liou-Brennan model had different results concerning the aberrations because of the decentration of the pupil. The MTF graphs showed small differences between the models because of the differences in their designs. CONCLUSION: All the three models are able to simulate accommodation with the expected results. There is no model that can be assumed as the best choice. Accommodation can be simulated in non-accommodativemodels and in customized ones.     

UV filter decomposition. A study of reactions of 4-(2-aminophenyl)-4-oxocrotonic acid with amino acids and antioxidants present in the human lens

Deamination of UV filters, such as kynurenine (KN), in the human lens results in protein modification. Thermal reactions of the product of kynurenine deamination, 4-(2-aminophenyl)-4-oxocrotonic acid (CKA), with amino acids (histidine, lysine, methionine, tryptophan, tyrosine, cysteine) and antioxidants (ascorbate, NADH, glutathione reduced) were studied. The rate constants of the reactions under physiological conditions were measured. The rate constants of CKA addition to cysteine k(Cys)=36+/-4M(-1)s(-1) and to glutathione k(GSH)=2.1+/-0.2M(-1)s(-1) are 4-5 orders of magnitude higher than the rate constants of CKA reactions with the other amino acids and antioxidants. The Arrhenius parameters for k(Cys) and k(GSH) were determined: A(GSH)=(1.8+/-0.7)x10(5)M(-1)s(-1), E(GSH)=29.2+/-5.6kJmol(-1), A(Cys)=(2.7+/-0.9)x10(8)M(-1)s(-1), E(Cys)=40.4+/-5.7kJmol(-1). The large difference in frequency factors for k(Cys) and k(GSH) is attributed to steric hindrance, peculiar to the bulky GSH molecule.     

Distribution of syndecans 1-4 within the anterior segment of the human eye: expression of a variant syndecan-3 and matrix-associated syndecan-2

Control of the actomyosin network plays a role in regulating the movement of aqueous humor through the anterior segment of the eye. Receptors that could control its activity are unknown. In this study, we show that all four members of the syndecan family, which can regulate the actomyosin network, are present within the anterior segment. In both sections of human anterior segments and cultures of human trabecular meshwork (HTM), Schlemm's canal (HSC) and the ciliary muscle (HCM) cells from the anterior segment, syndecans-3 and -4 were the predominant family members. They were widely distributed throughout the anterior segment. Syndecan-3 within the anterior segment was a novel, recently described variant 55 kDa form. Low levels of syndecans-1 and -2 were also observed in situ and in all three cultures. Their expression was weaker and more localized than that observed for syndecans-3 and -4. Staining for syndecan-1 in HCM cultures was variable. In HTM and HSC cultures, syndecan-2 also co-distributed with fibronectin, laminin and type IV collagen suggesting that it was shed and associated with the extracellular matrix. Western blots supported this idea and showed syndecan-2 ectodomains in lysates from anterior segments.