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We present new fluorophore-conjugates for dual-color photoactivation and super-resolution imaging inside live mammalian cells., We present new fluorophore-conjugates for dual-color photoactivation and super-resolution imaging inside live mammalian cells. These custom-designed, photo-caged Q-rhodamines and fluoresceins are cell-permeable, bright and localize specifically to intracellular targets. We utilized established orthogonal protein labeling strategies to precisely attach the photoactivatable fluorophores to proteins with subsequent activation of fluorescence by irradiation with UV light. That way, diffusive cytosolic proteins, histone proteins as well as filigree mitochondrial networks and focal adhesion proteins were visualized inside living cells. We applied the new photoactivatable probes in inverse fluorescence recovery after photo-bleaching (iFRAP) experiments, gaining real-time access to protein dynamics from live biological settings with resolution in space and time. Finally, we used the caged Q-rhodamine for photo-activated localization microscopy (PALM) on both fixed and live mammalian cells, where the superior molecular brightness and photo-stability directly resulted in improved localization precisions for different protein targets.

Secretion of insulin in response to extracellular stimuli, such as elevated glucose levels and small molecules that act on G-protein coupled receptors (GPCRs), is the hallmark of β-cell physiology. Sufficiently high blood insulin levels are ensured by the coupling of the secretory activity within pancreatic islets. Intercellular and inter-islet coordination are partly mediated by small diffusible ligands of GPCRs within the extracellular space of pancreatic islets. Therefore, insulin release is considered a synchronized multi-cellular process. We show herein that β-cell activity and insulin secretion essentially rely on the presence of extracellular endogenous (autocrine) signaling factors, exemplified by two classes of small cellular metabolites. Trace amines (TAs) are small aromatic metabolites that were identified as low-abundant ligands of the trace amine-associated receptor 1 (TAAR1) in the central nervous system (CNS). In the presented work, we identify TAs as essential autocrine signaling factors that maintain and regulate oscillations of the intracellular Ca2+ concentration ([Ca2+]i oscillations) along with insulin secretion from β-cells via TAAR1. We found that the modulation of endogenous TA levels by the selective inhibition of TA biosynthetic pathways directly translated into changes of [Ca2+]i oscillations and insulin secretion. Application of aromatic amine-withdrawing β-cyclodextrin temporarily reduced [Ca2+]i oscillations. This demonstrates the essential role of TAs for β-cell activity as well as their high metabolic turnover rates. Notably, herein applied inhibitors and synthetic TAAR1 (ant-)agonists are partly approved for the therapeutic modulation of biogenic amine levels within the CNS, and hence for the treatment of common neurological disorders. According to our findings, these drugs even affect β-cell activity and insulin secretion through pancreatic TAAR1. With the discovery of the free fatty acid (FA) receptor GPR40 in β-cells, FAs have come into focus as exogenous insulin secretagogues. However, the role of FAs as endogenous (local) signaling factors of β-cells has not been considered so far. We show herein that lowering endogenous FAlevels in the presence of FA-free bovine serum albumin (FAF-BSA) immediately reduced [Ca2+]i oscillations and insulin secretion. [Ca2+]i oscillations resumed upon exchange of FAF-BSA by buffer or upon restoration of extracellular FA pools. The latter was accomplished by the photolysis of caged FAs on plasma membranes, by the addition of a recombinant lipase or of FA-loaded BSA. Our approach to subordinate β-cell activity and insulin secretion to the presence of autocrine signaling factors of the yet underestimated receptors TAAR1 and GPR40 in the pancreas contributes to a more detailed and complete understanding of the fundamental regulation of β-cell activity and insulin secretion.

Amatoxins, which are mainly found in Amanita phalloides, Amanita virosa, and Galerina autumnalis, are responsible for the majority of fatal intoxication with green death cap. The intoxication is associated with acute liver failure, which explains the poor prognosis. Acute liver injury is generally preceeded by a gastrointestinal phase with nausea, vomiting and diarrhea. In the course, pre-renal kidney failure due to the associated fluid deficit and fulminant liver failure may occur. General guidelines for the treatment of amatoxin poisoning are yet not available. We report on three patients who suffered from amatoxin mushroom poisoning after ingestion of green death cap mushrooms. Based on the pathophysiology of amatoxin poisoning, we discuss a potential therapeutic approach.

Inositol pyrophosphates, such as diphospho-myo-inositol pentakisphosphates (InsP7), are an important family of signalling molecules, implicated in many cellular processes and therapeutic indications including insulin secretion, glucose homeostasis and weight gain. To understand their cellular functions, chemical tools such as photocaged analogues for their real-time modulation in cells are required. Here we describe a concise, modular synthesis of InsP7 and caged InsP7. The caged molecule is stable and releases InsP7 only on irradiation. While photocaged InsP7 does not enter cells, its cellular uptake is achieved using nanoparticles formed by association with a guanidinium-rich molecular transporter. This novel synthesis and unprecedented polyphosphate delivery strategy enable the first studies required to understand InsP7 signalling in cells with controlled spatiotemporal resolution. It is shown herein that cytoplasmic photouncaging of InsP7 leads to translocation of the PH-domain of Akt, an important signalling-node kinase involved in glucose homeostasis, from the membrane into the cytoplasm., Photocaged inositol-pyrophosphates offer a tool to study cellular signalling, but their challenging synthesis has precluded any biological studies so far. Here, the authors report the synthesis and cellular delivery of a photocaged analogue, and show that it mediates protein translocation in cellulo.

Our investigation aimed to evaluate the impact of endoscopic transpapillary forceps biopsies (ETP) in bile duct strictures of unknown etiology based on the largest European patient cohort at a tertiary referral center. To date only studies with limited patient numbers exist.Three-hundred-and-twelve patients (162 males, 150 females, mean age 62±12.7 years) with bile duct strictures of unknown etiology were examined with ETP. Sensitivity, specificity and accuracy of ETP were compared to the definite diagnosis proved by histopathology of surgical resection specimens or long-term follow-up of those patients not undergoing surgery.Using ETP a correct pe-interventional diagnosis was achieved in 211 out of 312 patients resulting in an accuracy rate of 67.6%. Eighty-six out of 187 malignant stenoses were correctly diagnosed by ETP, giving rise to sensitivity and specificity rates of 46 and 100%, respectively. Sensitivity of ETP in cholangiocellular carcinoma was significantly superior to that in pancreatic carcinoma (52.5% vs. 35.6%, p = 0.026). Sensitivity and accuracy rates of ETP did not depend on the localization of the stenosis in the common bile duct.ETP alone is not reliable enough in diagnosing bile duct malignancies as shown by low sensitivity and accuracy rates (false-negative rate of 32%).

Pneumocystis jirovecii pneumonia also known as pneumocystis pneumonia (PCP) is an opportunistic respiratory infection in human immunodeficiency virus (HIV) patients that may also develop in non-HIV immunocompromised persons. The aim of our study was to evaluate mortality predictors of PCP patients in a tertiary referral centre.Fifty-one patients with symptomatic PCP were enrolled in the study. The patients had either HIV infection (n = 21) or other immunosuppressive conditions (n = 30). Baseline characteristics (e.g. age, sex and underlying disease) were retrieved. Kaplan-Meier analysis was employed to calculate survival. Comparisons were made by log-rank test. A multivariate analysis of factors influencing survival was carried out using the Cox regression model. Chi-squared test and Wilcoxon-Mann-Whitney test was applied as appropriate.The median survival time for the HIV group was120 months compared with 3 months for the non-HIV group (P = 0.009). Three-month survival probability was also significantly greater in the HIV group compared with the non-HIV group (90% vs 41%, P = 0.002). In univariate log-rank test, intensive care unit (ICU) necessity, HIV negativity, age50 years, haemoglobin10g/dl, C-reactive protein 5 mg/dL and multiple comorbidities were significant negative predictors of survival. In the Cox regression model, ICU and HIV statuses turned out to be independent prognostic factors of survival.PCP is a serious problem in non-HIV immunocompromised patients in whom survival outcomes are worse than those in HIV patients.