Natural flavonoids as potential multifunctional agents in prevention of diabetic cataract

Cataract is one of the earliest secondary complications of diabetes mellitus. The lens is a closed system with limited capability to repair or regenerate itself. Current evidence supports the view that cataractogenesis is a multifactorial process. Mechanisms related to glucose toxicity, namely oxidative stress, processes of non-enzymatic glycation and enhanced polyol pathway significantly contribute to the development of eye lens opacity under conditions of diabetes. There is an urgent need for inexpensive, non-surgical approaches to the treatment of cataract. Recently, considerable attention has been devoted to the search for phytochemical therapeutics. Several pharmacological actions of natural flavonoids may operate in the prevention of cataract since flavonoids are capable of affecting multiple mechanisms or etiological factors responsible for the development of diabetic cataract. In the present paper, natural flavonoids are reviewed as potential agents that could reduce the risk of cataract formation via affecting multiple pathways pertinent to eye lens opacification. In addition, the bioavailability of flavonoids for the lens is considered

Size effect on fragmentation in tandem mass spectrometry.

International audienceThe collision energy or collision voltage necessary to obtain 50% fragmentation (characteristic collision energy/voltage, CCE or CCV) has been systematically determined for different types of molecules [poly(ethylene glycols) (PEG), poly(tetrahydrofuran) (PTHF), and peptides] over a wide mass (degrees of freedom) range. In the case of lithium-cationized PEGs a clear linear correlation (R(2) > 0.996) has been found between CCE and precursor ion mass on various instrument types up to 4.5 kDa. A similar linear correlation was observed between CCV and the mass-to-charge ratio. For singly and multiply charged polymers studied under a variety of experimental conditions and on several instruments, all data were plotted together and showed correlation coefficient R(2) = 0.991. A prerequisite to observe such a good linear correlation is that the energy and entropy of activation in a class of polymers is likely to remain constant. When compounds of different structure are compared, the CCV will depend not only on the molecular mass but the activation energy and entropy as well. This finding has both theoretical and practical importance. From a theoretical point of view it suggests fast energy randomization up to at least 4.5 kDa so that statistical rate theories are applicable in this range. These results also suggest an easy method for instrument tuning for high-throughput structural characterization through tandem MS: after a standard compound is measured, the optimum excitation voltage is in a simple proportion with the mass of any structurally similar analyte at constant experimental conditions

Ocular Disease, Knowledge and Technology Applications in Patients With Diabetes

An estimated 25.8 million children and adults in the United States, approximately 8.3% of the population, have diabetes. Diabetes prevalence varies by race and ethnicity. African Americans have the highest prevalence (12.6%), followed closely by Hispanics (11.8%), Asian Americans (8.4%), and Whites (7.1%). The purpose of this article is to discuss the ocular complications of diabetes, the cultural and racial differences in diabetes knowledge, and the role of telemedicine as a means to reach the undeserved who are at risk of complications. Information on the pathophysiology of ocular disease in patients with diabetes and the role of telemedicine in diabetes care was derived from a literature review. National Institutes of Health (NIH) on-line resources were queried to present data on the racial and cultural understandings of diabetes and diabetes-related complications. The microvascular ocular complications of diabetes are discussed for retinopathy, cataracts, glaucoma and ocular surface disease. Racial and cultural differences in knowledge of recommended self-care practices are presented. These differences in part, may explain health disparities and the increased risk of diabetes and its complications in rural minority communities. Finally, advances in telemedicine technology are discussed that show improvements in metabolic control and cardiovascular risk in adults with type 2 diabetes. Improving provider and patient understanding of diabetes complications may improve management and self care practices that are important for diabetes control. Telemedicine may improve access to diabetes specialists and may improve self-management education and diabetes control particularly in rural and underserved communities