Inter-individual variation in trophic history of Dosidicus gigas,as indicated by stable isotopes in eye lenses

Isotopic signatures have been extensively used to reconstruct marine organism trophic habitat over their lifetime.In this study,sequential stable isotopic values ofδ13C andδ15N in eye lenses were measured to investigate the trophic history of Dosidicus gigas during ontogeny.A total of 281 segments from 33 lenses were examined withδ13C ranging from−20.17‰to−16.11‰andδ15N ranging from 5.15‰to 18.74‰.Sequential increasing but variableδ13C andδ15N values in eye lenses indicated that the prey used in the model had a wide range of values,it became able to consume prey from higher trophic levels,perhaps to maximize feeding success.High inter-individual differences in the range and considerable inter-individual variation in the trend of the isotopic values of the sequential segments from the nuclear to the periphery were considered to be the result of the effects of food and the best feeding strategy.These inter-individual isotopic differences in the life history of D.gigas confirmed the high degree of plasticity of feeding for this squid and its high potential to adapt to environmental change.Inter-individual differences ofδ15N values in the growth of D.gigas were more likely to be caused by differences in the baseline values of isotopes.According to the population discrimination model ofδ15N value changes during ontogeny,the D.gigas off Peru fit the model of“generalist population-generalist individuals”.

Age-related changes in the kinetics of human lenses:prevention of the cataract

The crystalline lens is a transparent,biconvex structure in the eye that,along with the cornea,helps to refract light to be focused on the retina and,by changing shape,it adjusts focal distance（accommodation）.The three classes of structural proteins found in the lens areα,β,and γ crystallins.These proteins make up more than 90% of the total dry mass of the eye lens.Other components which can be found are sugars,lipids,water,several antioxidants and low weight molecules.When ageing changes occur in the lens,it causes a gradual reduction in transparency,presbyopia and an increase in the scattering and aberration of light waves as well as a degradation of the optical quality of the eye.The main changes that occur with aging are： 1） reduced diffusion of water from the outside to the inside of the lens and from its cortical to its nuclear zone; 2）crystalline change due to the accumulation of high molecular weight aggregates and insoluble proteins; 3）production of advanced glycation end products（AGEs）,lipid accumulation,reduction of reduced glutathione content and destruction of ascorbic acid.Even if effective strategies in preventing cataract onset are not already known,good results have been reached in some cases with oral administration of antioxidant substances such as caffeine,pyruvic acid,epigallocatechin gallate（EGCG）,α-lipoic acid and ascorbic acid.Furthermore,methionine sulfoxide reductase A（MSRA） over expression could protect lens cells both in presence and in absence of oxidative stress-induced damage.Nevertheless,promising results have been obtained by reducing ultraviolet-induced oxidative damage.

Severe prelenticular membrane formation on the surface of a hydrophilic acrylic intraocular lens after cataract surgery in an eye with an Ahmed valve implant

【正】Dear Sir,Iam Yong-Sun Ahn,from the Department of Ophthalmology of St.Vincent Hospital of Suwon,Kyungki-do,South Korea.Cataracts are a common problem in eyes with a glaucoma drainage device(GDD),because tube shunt surgery increases the incidence and progression of cataracts[1].An Ahmed valve,the most commonly inserted GDD,is composed of a silicone tube connected to a flat plate sewn to the sclera,and aqueous humor flows from the

Comparison of the effects of first and second generation silicone hydrogel contact lens wear on tear film osmolarity

AIM:To compare the effects of first and second generation silicone hydrogel(SiH) contact lens wear on tear film osmolarity.METHODS:The healthy subjects who have never used contact lenses before were enrolled in the study.Tear film osmolarity values of 16 eyes(group 1) who wore first generation SiH contact lenses were compared with those of 18 eyes(group 2) who wore second generation SiH contact lenses after three months follow-up.RESULTS:Beforecontactlenswear,tearfilmosmolarity of groups 1 and 2 were 305.02±49.08 milliosmole(mOsm) and 284.66±30.18mOsm,respectively.After three months of contact lens wear,osmolarity values were found 317.74±60.23mOsm in group 1 and 298.40±37.77mOsm in group 2.Although osmolarity values for both groups of SiH contact lens wear after three months periods were slightly higher than before the contact lens wear,the difference was not statistically significant. CONCLUSION:Contact lens wear may cause evaporation from the tear film and can increase tear film osmolarity leading to symptoms of dry eye disease.In the current study,there is a tendency to increase tear film osmolarity for both groups of SiH contact lens wear,but the difference is not statistically significant.

Hydrogel-based contact lens achieve prolonged,local drug delivery to the eye

With the support by the National Natural Science Foundation of China,the research group led by Prof.Jiang Gangbiao(蒋刚彪)at the Department of Pharmaceutical Engineering,College of Materials and Energy,South China Agricultural University,in collaboration with the research group led by Prof.Yuan