Autophagy and Exosomes in the Aged Retinal Pigment Epithelium: Possible Relevance to Drusen Formation and Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is a major cause of loss of central vision in the elderly. The formation of drusen, an extracellular, amorphous deposit of material on Bruch's membrane in the macula of the retina, occurs early in the course of the disease. Although some of the molecular components of drusen are known, there is no understanding of the cell biology that leads to the formation of drusen. We have previously demonstrated increased mitochondrial DNA (mtDNA) damage and decreased DNA repair enzyme capabilities in the rodent RPE/choroid with age. In this study, we found that drusen in AMD donor eyes contain markers for autophagy and exosomes. Furthermore, these markers are also found in the region of Bruch's membrane in old mice. By in vitro modeling increased mtDNA damage induced by rotenone, an inhibitor of mitochondrial complex I, in the RPE, we found that the phagocytic activity was not altered but that there were: 1) increased autophagic markers, 2) decreased lysosomal activity, 3) increased exocytotic activity and 4) release of chemoattractants. Exosomes released by the stressed RPE are coated with complement and can bind complement factor H, mutations of which are associated with AMD. We speculate that increased autophagy and the release of intracellular proteins via exosomes by the aged RPE may contribute to the formation of drusen. Molecular and cellular changes in the old RPE may underlie susceptibility to genetic mutations that are found in AMD patients and may be associated with the pathogenesis of AMD in the elderly

Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease

BACKGROUND: Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization. RESULTS: During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events. CONCLUSIONS: Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)

Hydrographical and biological investigations in Norwegian fiords /

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Growth Hormone, Glutamine, and an Optimal Diet Reduces Parenteral Nutrition in Patients With Short Bowel Syndrome: A Prospective, Randomized, Placebo-Controlled, Double-Blind Clinical Trial

OBJECTIVE: To determine if growth hormone (GH) and glutamine (Gln) might allow for a reduction in parenteral nutrition (PN) in individuals with short bowel syndrome. BACKGROUND DATA: Following massive intestinal resection, patients frequently sustain severe nutrient malabsorption and are dependent on PN for life. GH treatment with or without Gln might allow for a reduction in PN. METHODS: A prospective, double-blind, randomized, placebo-controlled clinical trial performed in 41 adults dependent on PN. Following screening, patients were admitted to an in-house facility for 6 weeks. After 2 weeks of stabilization and dietary optimization, patients were randomized to one of 3 treatment arms (1:2:2 ratio): oral Gln (30 g/day) + GH placebo (control group, n = 9), Gln placebo + GH (0.1 mg/kg per day, n = 16), or Gln + GH (n = 16). Standard criteria based on clinical and laboratory measurements were followed to determine PN volume and content. After 4 weeks of treatment, patients were discharged and monitored; GH and GH placebo were discontinued, but the diet with Gln or Gln placebo was continued for 3 months. RESULTS: Patients receiving GH + Gln placebo + diet showed greater reductions in PN volume (5.9 ± 3.8 L/wk, mean ± SD), PN calories (4338 ± 1858 calories/wk), and PN infusions (3 ± 2 infusions/wk) than corresponding reductions in the Gln + diet group (3.8 ± 2.4 L/wk; 2633 ± 1341 calories/wk; 2 ± 1 infusions/wk, P < 0.05). Patients who received GH + Gln + diet showed the greatest reductions (7.7 ± 3.2 L/wk; 5751 ± 2082 calories/wk; 4 ± 1 infusions/wk, P < 0.001 versus Gln + diet). At the 3-month follow-up, only patients who had received GH + Gln + diet maintained significant reductions in PN (P < 0.005) compared with the Gln + diet. CONCLUSIONS: Treatment with GH + diet or GH + Gln + diet initially permitted significantly more weaning from PN than Gln + diet. Only subjects receiving GH + Gln + diet maintained this effect for at least 3 months