Macular

The newest molecular addition to Cl- channels are bestrophins [5]. There are four different bestrophin isoforms in humans. Mutations in Bestl cause Best macular dystrophy, hence their name. All four isoforms induce chloride currents when expressed heterologously. Although they show a dependence on intracellular calcium, their biophysical properties differ from Ca-activated chloride currents typically observed in native cells. Mutagenesis experiments changed the activation of currents and induced slight changes in ion selectivity, lending support to the hypothesis that bestrophins themselves are Cl- channels. 

Ranibizumab Anti-FAB fragment of VEGF Macular degeneration... 

Ferrara N, Damico L, Shams N, et al (2006) Developmemt of Ranibizumab, an anti-vascular endothelial growth factor antigen binding fragment, as therapy for neovascular age-related macular degeneration. Retina 26 859-870... 

The differential diagnosis for PIH includes the following fixed drug eruption, systemic drug-induced hyperpigmentation, macular amyloid, ashy dermatosis, melasma, and tinea versicolor. Medications such as tetracyclines, antimalarial drugs, arsenic, bleomycin, and doxorubicin can result in hyperpigmentation of the skin. 

Solar lentigo are a macular area of brown pigmentation appearing after either acute or chronic sun exposure. The term solar lentigo is In younger patients solar lentigo are seen on preferred to senile lentigo, which is sometimes sim-exposed areas (Fig. i8.i). There is usually a... 

Christiansen C, Dreborg S. Pichler WJ. Ekeli H Macular exanthema appearing 5 days after X-ray contrast medium administration. Eur Radiol 2002 12(suppl 3) S94-S97. 

Most carotenoids have no pro-vitamin A activity with the notable exceptions of P-carotene, and to a lesser extent a-carotene and P-cryptoxanthin. They act as macular pigments (lutein and zeaxanthin) and they have antioxidant and biochemical properties other than pro-vitamin A activity. 

JOHNSON E J, HAMMOND B R, YEUM K, J, QIN J, WANG X D, CASTANEDA C, SNODDERLY D M and RUSSELL R M (2000) Relation among serum and tissue concentrations of lutein and zeaxanthin and macular pigment density. Am J Clin Nutr. 71(6) 1555-62. 

LUTTY G, GRUNWALD J, MAjji A B, UYAMA M and YONEYA s (1999) Changes in choriocapillaris and retinal pigment epithelium (RPE) in age-related macular degeneration. Mol Vis. 5 35-8. 

COOPER D A, ELDRiDGE A L and PETERS J c (1999) Dietary carotenoids and certain cancers, heart disease and age-related macular degeneration a review of recent research , iVMtr Rev, 57, 201-14. 

LANDRUM J T and BONE R A (2001) Lutein, zeaxanthin, and the macular pigment . Arch Biochem Biophys, 385, 28-40. 

Landrum, J.T. and Bone, R.A., Lutein, zeaxanthin and the macular pigment. Arch. Biochem. Biophys., 385, 28, 2001. 

Comprehensive reviews published by Snodderly and Beatty et al. " explore the evidence for a protective fnnction by the macular pigment against age-related macnlar diseases and the mechanisms by which it might act. The antioxidant properties of Intein and zeaxanthin recently reviewed by Young and Lowe may rednce the degree to which oxidative damage promotes these diseases. Otherwise, becanse these... 

Snodderly, D.M., Evidence for protection against age-related macular degeneration by carotenoids and antioxidant vitamins. Am. J. Clin. Nutr, 62, 1448S, 1995. 

Beatty, S. et al.. The role of oxidative stress in the pathogenesis of age-related macular degeneration, Surv. Ophthalmol, 45, 115, 2000. 

Landrum, J.T. et al., The macular pigment a possible role in protection from age-related macular degeneration, Adv. Pharmacol, 38, 537, 1997. 

Whitehead, A.J. et ah. Macular pigment a review of current knowledge. Arch. Ophthalmol, 124, 1038, 2006. 

Wisniewska, A. and Subczynski, W.K., Accumulation of macular xanthophylls in unsaturated membrane domains. Free Radio. Biol. Med., 40, 1820, 2006. 

In the Unites States, the daily intake of 3-carotene is around 2 mg/day Several epidemiological studies have reported that consumption of carotenoid-rich foods is associated with reduced risks of certain chronic diseases such as cancers, cardiovascular disease, and age-related macular degeneration. These preventive effects of carotenoids may be related to their major function as vitamin A precursors and/or their actions as antioxidants, modulators of the immune response, and inducers of gap-junction communications. Not all carotenoids exert similar protective effects against specific diseases. By reason of the potential use of carotenoids as natural food colorants and/or for their health-promoting effects, research has focused on better understanding how they are absorbed by and metabolized in the human body. 

Astaxanthin is a powerful bioactive antioxidant and has demonstrated efficacy in animal and human models of macular degeneration, a cause of blindness in a large population. It is also helpful in treating Alzheimer s and Parkinson s diseases and is known to offer protection against cancer. 

Tso and Lam suggested that astaxanthin could be useful for prevention and treatment of neuronal damage associated with age-related macular degeneration and may also be effective in treating ischemic reperfusion injury, Alzheimer s disease, Parkinson s disease, spinal cord injuries, and other types of central nervous system injuries. Astaxanthin was found to easily cross the blood-brain barrier and did not form crystals in the eye. 

In a 20-week multicenter intervention trial with lutein in healthy human subjects, no changes were noted in hematological or biochemical parameters after continuous daily lutein doses of 15 mg (0.25 mg/kg body weight, assuming a body weight of 60 kg). A relatively large number of human studies have examined correlations between macular degeneration and dietary intake of lutein or zeaxanthin, intakes via dietary supplements, and serum concentrations. 

Smith, R.E. and Nozik, R.A. (1989). Cystoid macular oedema and uveitis. In Uveitis A Clinical Approach to Diagnosis and Management , 2nd edn. pp. 108-119. Williams and Wilkins, Baltimore. 

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