The Role of Oxidative Stress in the Pathogenesis of Age-Related Macular Degeneration

The epidemiologic literature in the English language regarding intake of tomatoes and tomato-based products and blood lycopene (a compound derived predominantly from tomatoes) level in relation to the risk of various cancers was reviewed. Among 72 studies identified, 57 reported inverse associations between tomato intake or blood lycopene level and the risk of cancer at a defined anatomic site; 35 of these inverse associations were statistically significant. No study indicated that higher tomato consumption or blood lycopene level statistically significantly increased the risk of cancer at any of the investigated sites. About half of the relative risks for comparisons of high with low intakes or levels for tomatoes or lycopene were approximately 0.6 or lower. The evidence for a benefit was strongest for cancers of the prostate, lung, and stomach. Data were also suggestive of a benefit for cancers of the pancreas, colon and rectum, esophagus, oral cavity, breast, and cervix. Because the data are from observational studies, a cause-effect relationship cannot be established definitively. However, the consistency of the results across numerous studies in diverse populations, for case-control and prospective studies, and for dietary-based and blood-based investigations argues against bias or confounding as the explanation for these findings. Lycopene may account for or contribute to these benefits, but this possibility is not yet proven and requires further study. Numerous other potentially beneficial compounds are present in tomatoes, and, conceivably, complex interactions among multiple components may contribute to the anticancer properties of tomatoes. The consistently lower risk of cancer for a variety of anatomic sites that is associated with higher consumption of tomatoes and tomato-based products adds further support for current dietary recommendations to increase fruit and vegetable consumption.

/pdf/tomatoes-tomato-based-products-lycopene-and-cancer-review-of-58ewr3o8rf.pdf

Tomatoes, Tomato-Based Products, Lycopene, and Cancer: Review of the Epidemiologic Literature

https://faculty.missouri.edu/~glaserr/3700s14/Antioxidant_Carotenoids_2005.pdf

Carotenoid actions and their relation to health and disease.

Objective To review and synthesize information concerning the pathogenesis ofage-related macular degeneration (AMD). Methods Review of the English-language literature. Results Five concepts relevant to the cell biology of AMD are as follows: (1)AMD involves aging changes plus additional pathological changes (ie, AMD isnot just an aging change); (2) in aging and AMD, oxidative stress causes retinalpigment epithelial (RPE) and, possibly, choriocapillaris injury; (3) in AMD(and perhaps in aging), RPE and, possibly, choriocapillaris injury resultsin a chronic inflammatory response within the Bruch membrane and the choroid;(4) in AMD, RPE and, possibly, choriocapillaris injury and inflammation leadto formation of an abnormal extracellular matrix (ECM), which causes altereddiffusion of nutrients to the retina and RPE, possibly precipitating furtherRPE and retinal damage; and (5) the abnormal ECM results in altered RPE-choriocapillarisbehavior leading ultimately to atrophy of the retina, RPE, and choriocapillarisand/or choroidal new vessel growth. In this sequence of events, both the environmentand multiple genes can alter a patient's susceptibility to AMD. Implicit inthis characterization of AMD pathogenesis is the concept that there is linearprogression from one stage of the disease to the next. This assumption maybe incorrect, and different biochemical pathways leading to geographic atrophyand/or choroidal new vessels may operate simultaneously. Conclusions Better knowledge of AMD cell biology will lead to better treatmentsfor AMD at all stages of the disease. Many unanswered questions regardingAMD pathogenesis remain. Multiple animal models and in vitro models of specificaspects of AMD are needed to make rapid progress in developing effective therapiesfor different stages of the disease.

https://jamanetwork.com/journals/jamaophthalmology/articlepdf/416250/EMO20000.pdf

Current Concepts in the Pathogenesis of Age-Related Macular Degeneration

https://febs.onlinelibrary.wiley.com/doi/pdf/10.1016/0014-5793%2896%2900323-7

Antioxidant activities of carotenes and xanthophylls

Carotenoids protect against cell membrane damage by the nitrogen dioxide radical.

Interactions between Carotenoids and the CCl3O2.bul. Radical

A physical chemistry technique based on singlet oxygen luminescence at about 1270 nm and a biological cell membrane technique were used to study the quenching of singlet oxygen by four carotenoids bound to the surface of lymphoid cells. All the carotenoids studied showed a beneficial effect in cell protection, but there were subtle differences between them.

Dietary carotenoids protect human cells from damage.

The interaction of carotenoids with reactive oxy-species

The COVID-19 pandemic caused the closures of schools worldwide and a move to remote learning. This article presents the findings of a study that explored the use of digital technology during school closures in Australia, drawing on the perspectives of primary school teachers and parents. Data were collected using Facebook groups and semi-structured interviews, and a thematic analysis conducted. The results describe seven themes associated with the teacher and parent experiences of remote learning: learning how to teach and learn remotely; learning to use technology; moving away from technology; hardware and internet access; collaboration and communication; social connection; and technology and engagement. The findings indicate the need to prioritise teachers’ technological and pedagogical skills as standard practice; include parents in the development of remote learning skills; and move away from transformative rhetoric around educational technologies to a more realistic and needs-based approach. 

J H Tinkler

Papers

Carotenoids protect against cell membrane damage by the nitrogen dioxide radical.

Interactions between Carotenoids and the CCl3O2.bul. Radical

Dietary carotenoids protect human cells from damage.

The interaction of carotenoids with reactive oxy-species

Transformative rhetoric and educational technologies: digital technologies for schooling during the COVID-19 pandemic