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Mckinney Parks posted an update 6 months, 2 weeks ago
Since the recognition of the reactive oxygen species singlet oxygen (1O2) as a versatile signal that induces various stress responses, the mechanisms underlying 1O2-induced signaling transduction pathways have become the subject of much current research. This in turn highlights the need for reliable detection methods for 1O2. Here we describe a protocol for the detection of 1O2 using a commercially available fluorescent probe (Singlet Oxygen Sensor Green) and provide a simple method for direct visualization and quantification of the 1O2-evolving photosensitizer protochlorophyllide in the Arabidopsis fluorescent mutant.Reactive oxygen species (ROS) may severely affect the biochemical viability of most cells. However, ROS may act also as key second messengers regulating important physiological functions in eukaryotic organisms. Of special interest is the potential role of ROS in the regulation of stem cell function and tissue homeostasis and regeneration in adult mammalian tissues. In this context, the hair follicle constitutes an excellent experimental model to study this aspect of ROS biology.Here we present a robust protocol to promote a sustained growth of ex vivo cultured human hair follicles based on the induction of a transient/modulable production of nonlethal endogenous ROS levels in the tissue through a protoporphyrin IX-dependent photodynamic procedure. The light-switchable ROS production activates hair follicle stem cell niches, induces cell proliferation, and maintains the growth/anagen phase for long time. This approach constitutes a complementary experimental tool to study the physiological roles of ROS in human tissues.Redox signaling implication in cell adaptation to hypoxia has been studied for a long time, both in long-term and acute responses. selleck kinase inhibitor However, measurement of superoxide and other reactive oxygen species (ROS) in acute hypoxia is technically challenging, for example, because of the need to overcome the effect of cell reoxygenation before measurement.Here we describe a method we have developed for measuring superoxide production in acute hypoxia using the fluorescent probe dihydroethidine in fixed-cell microscopy. The method allows measuring the kinetics of superoxide production (or other ROS with the appropriate probes) by incubating the probe in different time windows during hypoxia incubation.Production of reactive oxygen species (ROS) in the mitochondria plays multiple roles in physiology, and excessive production of ROS leads to the development of various pathologies. ROS in the mitochondria are generated by various enzymes, mainly in the electron transporvt chain, and it is important to identify not only the trigger but also the source of free radical production. It is important to measure mitochondrial ROS in live, intact cells, because activation of ROS production could be initiated by changes in extramitochondrial processes which could be overseen when using isolated mitochondria. Here we describe the approaches, which allow to measure production of ROS in the matrix of mitochondria in live cells. We also demonstrate how to measure kinetic changes in lipid peroxidation in mitochondria of live cells. These methods could be used for understanding the mechanisms of pathology in a variety of disease models and also for testing neuro- or cardioprotective chemicals.This book chapter is drafted for biologists with experimental experiences in ROS biology but being newcomers in the field of modeling. We start with a general introduction about computational modeling in biology and an overview of software tools suitable for beginners. This chapter encompasses an introduction to computational models with special focus on simulation of ROS dynamics. A step-by-step tutorial follows providing guidance for all relevant model development processes. This course of action gives a comprehensible way to understand the benefits of computational models and to gain the necessary knowledge to build own small equation-based models. Small models can be created without any special programming expertise or in-depth technical and mathematical knowledge. Afterward in the final section, a short overview of pitfalls, challenges, and limitations is provided, combined with suggestions for further reading to improve and expand modeling skills of biologists.
Multidetector computed tomographic urography (MDCTU) is not yet sufficient to be used in the clinical staging of upper tract urothelial carcinoma (UTUC). This study aimed to compare the diagnostic accuracy of MDCTU T stage classification and pathologic T staging for UTUC.
We retrospectively evaluated 125 patients with UTUC who underwent preoperative MDCTU. A single radiologist classified the MDCTU pattern of the tumors as either low or advanced T stage for localized or locally advanced tumors, respectively. The diagnostic values of MDCTU for locally advanced tumors and the kappa agreement between MDCTU and pathologic T stage were investigated.
Among 85 pathologic low T stage (Ta-T2) tumors, 71 low T stage tumors were correctly detected by MDCTU, while 30 out of 40 advanced T stage (T3-T4) tumors were correctly diagnosed by MDCTU. MDCTU led to under-staging in 8% (10/125) tumors and over-staging in 11.2% (14/125) tumors. Therefore, the overall accuracy of MDCTU in the diagnosis of low and advanced T stage tumors was 80.8% (101/125 patients). The sensitivity for advanced T stage tumors was 75% (30/40), the specificity was 83.5% (71/85), and the positive and negative predictive values were 68.1% (30/44) and 87.6% (71/81), respectively. The kappa agreement value between the MDCTU T stage and pathologic T stage was 0.57 (95% confidence interval (CI) 0.42-0.72), which was statistically significant (Pā=ā0.001).
MDCTU T stage classification may be relatively accurate for the detection and staging of UTUC correspondence with a pathologic stage.
MDCTU T stage classification may be relatively accurate for the detection and staging of UTUC correspondence with a pathologic stage.
The incidence of pancreatic cancer is increasing in developed countries. The incorporation of new therapies, to the first-line treatment of patients with good performance status led to better survival in clinical trials. However, there is a wide variability in their use and some concerns about the treatment of elderly patients who were not included in the clinical trials.
This is a retrospective multicenter study. Data from consecutive patients diagnosed with metastatic pancreatic cancer (mPC) treated with FOLFIRINOX (FFX) or gemcitabine plus nab-paclitaxel (GnP) were analysed to evaluate efficacy (overall survival-OS) and toxicity.
A total of 119 patients were included. 49.6% were treated with FFX and 50.4% with GNP in first-line. The median OS was 12months with no statistically significant differences between both regimens (12.7m for FFX vs 10.2m for GnP). Elevated Ca 19.9 levels and neutrophil-lymphocyte ratio (NLR) increased the risk of death. Patients who received both regimens in first/second line had a median OS longer than 15months whichever the sequence.