Tumor cells are protected against intercellular reactive oxygen species (ROS)-mediated apoptosis signaling mediated by the HOCl and/or the nitric oxide (NO)/peroxynitrite signaling pathway. We have recently shown that tumor cell resistance against HOCl signaling can be abrogated through inhibition of catalase. The protection of tumor cells against the NO/peroxynitrite signaling pathway has remained enigmatic so far. Here, we show that suboptimal inhibition of catalase by 3-aminotriazole or a monoclonal antibody against catalase, as well as partial knockdown of catalase by specific siRNA allows selective reactivation of the NO/peroxynitrite pathway in MKN 45 gastric carcinoma cells, followed by the HOCl pathway at higher inhibitor or siRNA concentrations. In SKN-MC Ewing sarcoma cells, catalase inhibition causes apoptosis induction solely based on the NO/peroxynitrite pathway. Protection against NO/peroxynitrite signaling is shown to be due to the potential of catalase to decompose peroxynitrite. The direct interaction of catalase with peroxynitrite is verified through the detection of compound I (CAT Fe(IV)=O(+)*) after the interaction of peroxynitrite with catalase. In a complementary experiment, addition of catalase protects sensitive transformed cells against ROS-mediated apoptosis induction. Thus, the expression of membrane-associated catalase is sufficient to protect tumor cells against multiple intercellular ROS-mediated signaling pathways.

MR imaging of superficial cranial arteries is accurate in the initial diagnosis of GCA giant cell arteritis . Sensitivity probably decreases after more than 5 days of sCS systemic corticosteroid therapy; thus, imaging should not be delayed. Clinical trial registration no. DRKS00000594 .

We found that donor age and endothelial cell density influence the properties of DMEK grafts, and thereby the duration of the surgical procedure. Increased unfolding times result in higher endothelial cell loss. Therefore, it seems reasonable to accept preferably older donors with high endothelial cell densities for DMEK, which may be particularly true for inexperienced surgeons or complex clinical situations.

CMO is a frequent complication following DMEK in phacic and pseudophacic eyes. The prognosis is excellent given medical treatment. We recommend regular SD-OCT monitoring during the first 6 months following DMEK.

In contrast to recent reports from national keratoplasty registers, the overall clinical outcome of EK in FED and BK is superior to PK. Including ocular comorbidities and learning curves, these data reflect a realistic setting for comparing the different keratoplasty techniques. Corneal surgeons may be encouraged to preferentially use DMEK in FED and BK.

Oncogenic transformation is dependent on activated membrane-associated NADPH oxidase (NOX). However, the resultant extracellular superoxide anions are also driving the NO/peroxynitrite and the HOCl pathway, which eliminates NOX-expressing transformed cells through selective apoptosis induction. Tumor progression is dependent on dominant interference with intercellular apoptosis-inducing ROS signaling through membraneassociated catalase, which decomposes H 2 O 2 and peroxynitrite and oxidizes NO. Particularly, the decomposition of extracellular peroxynitrite strictly requires membraneassociated catalase. We utilized small interfering RNA (siRNA)-mediated knockdown of catalase and neutralizing antibodies directed against the enzyme in combination with challenging H 2 O 2 or peroxynitrite to determine activity and localization of catalase in cells from three distinct steps of multistage oncogenesis. Nontransformed cells did not generate extracellular superoxide anions and only showed intracellular catalase activity. Transformed cells showed superoxide anion-dependent intercellular apoptosis-inducing ROS signaling in the presence of suboptimal catalase activity in their membrane. Tumor cells exhibited tight control of intercellular apoptosis-inducing ROS signaling through a high local concentration of membrane-associated catalase. These data demonstrate that translocation of catalase to the outside of the cell membrane is already associated with the transformation step. A strong local increase in the concentration of membrane-associated catalase is achieved during tumor progression and is controlled by tumor cell-derived H 2 O 2 and by transglutaminase.

PurposeTo study the impact of soluble IL2 receptor (sIL2R), chest x-ray (CxR), and angiotensin-converting enzyme (ACE) as markers for sarcoidosis in uveitis patients.DesignRetrospective study.MethodsSerum concentrations of sIL2R and ACE were measured in patients with active uveitis. Those with elevated sIL2R and /or ACE values were examined for suspected systemic sarcoidosis.Main Outcome MeasureOur main outcome parameters were the specificity and sensitivity of sIL2R, CxR and ACE in screening for ocular sarcoidosis.ResultsWe measured 261 patients with uveitis for sarcoidosis using sIL2R and ACE between January 2008 and November 2011; sarcoidosis was been diagnosed using other tests (e.g. computer tomography, brochoalveolar lavage, biopsy) in 41 of 53 patients with elevated sIL2R values (>639 U/ml) and in one patient with normal sIL2R (582 U/ml). Their mean sIL2R value was 1310 U/ml, extending from 582 to 8659 U/ml. Only 9 patients, however, presented elevated ACE (>82 U/l). Their mean ACE value was 116.4 U/l, ranging from 84.1 to 175.5 U/l. IL2R specificity was 94% with 98% sensitivity. In contrast, ACE had a specificity of 99.5%, but a sensitivity of only 22%; the chest x-ray had a specificity of 100% with 50% sensitivity in detecting sarcoidosis. We observed the entire spectrum of uveitis: sixteen patients suffered from anterior, 8 from intermediate, 16 from posterior, and 2 from panuveitis.ConclusionsAn elevated level of soluble IL2R suggests sarcoidosis with uveitis more convincingly than ACE, making sIL2R a more effective marker parameter for sarcoidosis than ACE or chest x-ray in uveitis patients.

BackgroundPatients with intermediate uveitis (IU) represent a heterogenous group characterized by a wide spectrum of etiologies and regional differences. Aim of the study was to analyze the characteristics of patients with IU examined in an academic center in Germany.MethodsWe conducted a retrospective analysis of the clinical records of all patients with intermediate uveitis referred to the Eye Center, University of Freiburg from 2007 to 2014. Diagnosis followed the Standardization in Uveitis Nomenclature (SUN) criteria. Data analysis included: etiology of IU, demographics, complications, treatment and visual acuity.ResultsWe identified 159 patients with intermediate uveitis during that period. Mean age at diagnosis was 35 years. Most are female (64%), and the mean duration of IU was 6.1 years (range 1 month – 35 years). Etiology of IU was idiopathic in 59%. Multiple sclerosis (MS) (20%) and sarcoidosis (10%) were frequent systemic causes of IU. Other etiologies including infectious diseases (tuberculosis, borreliosis) or immune-mediated conditions (eg, after vaccination) were present in 11%. The pattern of complications included macular edema (CME) (36%), cataract (24%), secondary glaucoma (7%), and epiretinal membrane formation (19%). Periphlebitis and optic neuritis were more frequent in conjunction with MS. Treatment comprised local and systemic steroids, immunosuppressive agents, biologics, and surgery. Best corrected visual acuity was better than 20/25 in 60% of the eyes after more than 10 years of follow-up.ConclusionsIn our German academic center, most IU cases were idiopathic or associated with MS or sarcoidosis. In contrast to other countries, infectious cases were rare. Patients’ overall visual prognosis is favorable even when the duration of IU has been long and and despite numerous complications.