S and inflammation have been linked to AMD [8]. Copper and zinc

S and inflammation have been linked to AMD [8]. Copper and zinc play vital roles in retinal function and are essential for antioxidant defense mechanisms [9], which are important for the survival of the retina, who is routinely exposed to high levels of oxidative stress from light and metabolic processes. Both copper and zinc are known to be necessary for the visual cycle and photoreceptor survival. These metals act as co-factors for the antioxidant enzyme copper-zinc superoxide dismutase, which catalyzes the conversion of superoxide to oxygen and hydrogen peroxide (H2O2). Copper and zinc also stimulateTrace Elements in AMDprotective GNF-7 cost cellular stress-signaling pathways and stabilize proteins, making them less vulnerable to oxidation. Cobalt is an essential trace element for humans, but becomes toxic at high concentrations [10]. Selenium-containing glutathione peroxidase is an important part of the cellular antioxidative system, and selenium itself is widely used in dietary supplements. Polymorphisms of manganese superoxide dismutase (MnSOD) genes may be associated with the development of AMD [11]. Based on this evidence, the aim of this study was to measure alterations of aqueous humor trace elements levels in patients with AMD.Laboratory analysisAll patients with AMD and controls underwent cataract surgery with phacoemulsification. Aqueous humor samples were obtained intraoperatively before fashioning of the corneal tunnel. 100 to 150 ml of aqueous humor was withdrawn through an ab-externo limbal paracentesis site using a 27-gauge needle on a tuberculin syringe, with special care to avoid blood contamination. The samples were immediately frozen in liquid nitrogen and stored in a deep freezer at 280uC until biochemical analysis. Cadmium, cobalt, copper, iron, manganese, selenium, and zinc were measured using Flow-Injection-Inductively-Coupled-PlasmaMass-Spectrometry (FI-ICP-MS) following certified standards.Patients and Methods Ethics StatementThe present prospective case-control study was approved by the Institutional Review Board of the University of ErlangenNurnberg. After detailed explanation of the purpose and methods ?of the study, written and informed consent was obtained from the subjects, who were all German, before participating. The study was conducted in adherence to the hPTH (1-34) biological activity tenets of the Declaration of Helsinki.Elemental analysisDue to the small sample volumes available, a combination of flow injection sample introduction with ICP-MS detection was used. The flow injection sample introduction was conducted by coupling a Knauer 1100 Smartline inert Series HPLC system to the ICP-MS. The HPLC system was equipped with an electronic valve with a 25 ml injection loop (Perkin Elmer, RodgauJugesheim, 15900046 Germany). The flow rate was 1 ml/min of Milli-Q ?water. The outlet of the injector port was directly connected to the nebulizer of the ICP-MS by PEEK (polyetheretherketone) capillary tubing (0.125 cm i.d., ca. 80 cm). Instrumental settings for ICP-MS are shown in table 3. Calibrations were performed with daily fresh prepared standard solutions in the ranges 0?1000 ng/L for Cd, Co, Hg, Mn, Pb, Se or 0?00 mg/L for Cu, Fe, Zn. R2 values were 0.989 for Zn and better than 0.999 for the other elements. For each element a 5-point calibration curve was achieved and sample peak areas were related to respective element calibrations. Cd : y 10:025xz270:Patients and designAt the University Eye Hospital Erlangen, patients who underwent cataract surgery a.S and inflammation have been linked to AMD [8]. Copper and zinc play vital roles in retinal function and are essential for antioxidant defense mechanisms [9], which are important for the survival of the retina, who is routinely exposed to high levels of oxidative stress from light and metabolic processes. Both copper and zinc are known to be necessary for the visual cycle and photoreceptor survival. These metals act as co-factors for the antioxidant enzyme copper-zinc superoxide dismutase, which catalyzes the conversion of superoxide to oxygen and hydrogen peroxide (H2O2). Copper and zinc also stimulateTrace Elements in AMDprotective cellular stress-signaling pathways and stabilize proteins, making them less vulnerable to oxidation. Cobalt is an essential trace element for humans, but becomes toxic at high concentrations [10]. Selenium-containing glutathione peroxidase is an important part of the cellular antioxidative system, and selenium itself is widely used in dietary supplements. Polymorphisms of manganese superoxide dismutase (MnSOD) genes may be associated with the development of AMD [11]. Based on this evidence, the aim of this study was to measure alterations of aqueous humor trace elements levels in patients with AMD.Laboratory analysisAll patients with AMD and controls underwent cataract surgery with phacoemulsification. Aqueous humor samples were obtained intraoperatively before fashioning of the corneal tunnel. 100 to 150 ml of aqueous humor was withdrawn through an ab-externo limbal paracentesis site using a 27-gauge needle on a tuberculin syringe, with special care to avoid blood contamination. The samples were immediately frozen in liquid nitrogen and stored in a deep freezer at 280uC until biochemical analysis. Cadmium, cobalt, copper, iron, manganese, selenium, and zinc were measured using Flow-Injection-Inductively-Coupled-PlasmaMass-Spectrometry (FI-ICP-MS) following certified standards.Patients and Methods Ethics StatementThe present prospective case-control study was approved by the Institutional Review Board of the University of ErlangenNurnberg. After detailed explanation of the purpose and methods ?of the study, written and informed consent was obtained from the subjects, who were all German, before participating. The study was conducted in adherence to the tenets of the Declaration of Helsinki.Elemental analysisDue to the small sample volumes available, a combination of flow injection sample introduction with ICP-MS detection was used. The flow injection sample introduction was conducted by coupling a Knauer 1100 Smartline inert Series HPLC system to the ICP-MS. The HPLC system was equipped with an electronic valve with a 25 ml injection loop (Perkin Elmer, RodgauJugesheim, 15900046 Germany). The flow rate was 1 ml/min of Milli-Q ?water. The outlet of the injector port was directly connected to the nebulizer of the ICP-MS by PEEK (polyetheretherketone) capillary tubing (0.125 cm i.d., ca. 80 cm). Instrumental settings for ICP-MS are shown in table 3. Calibrations were performed with daily fresh prepared standard solutions in the ranges 0?1000 ng/L for Cd, Co, Hg, Mn, Pb, Se or 0?00 mg/L for Cu, Fe, Zn. R2 values were 0.989 for Zn and better than 0.999 for the other elements. For each element a 5-point calibration curve was achieved and sample peak areas were related to respective element calibrations. Cd : y 10:025xz270:Patients and designAt the University Eye Hospital Erlangen, patients who underwent cataract surgery a.