Search results for "Bioluminescence"
showing 10 items of 46 documents
Mechanism of activated chemiluminescence of cyclic peroxides: 1,2-dioxetanes and 1,2-dioxetanones
2017
Almost all chemiluminescent and bioluminescent reactions involve cyclic peroxides. The structure of the peroxide and reaction conditions determine the quantum efficiency of light emission. Oxidizable fluorophores, the so-called activators, react with 1,2-dioxetanones promoting the former to their first singlet excited state. This transformation is inefficient and does not occur with 1,2-dioxetanes; however, they have been used as models for the efficient firefly bioluminescence. In this work, we use the SA-CASSCF/CASPT2 method to investigate the activated chemiexcitation of the parent 1,2-dioxetane and 1,2-dioxetanone. Our findings suggest that ground state decomposition of the peroxide com…
Bioluminescent-like squamation in the galeomorph shark Apristurus ampliceps (Chondrichthyes: Elasmobranchii)
2018
Galeomorph sharks constitute the most taxonomically and ecologically diverse superorder of living selachians. Despite comprising several typically deep-water taxa, no bioluminescent species have been reported in this group so far. Interestingly, the study of shark squamation has been revealed in recent years to be a good proxy for inferring some ecological aspects of poorly known species. In particular, the high morphological specificity of the dermal denticles and the squamation patterns of all currently-known bioluminescent sharks could constitute a potential tool for predicting bioluminescence in both fossil and living taxa. Following this idea, we provide the first evidence supporting t…
Potential of induced metabolic bioluminescence imaging to uncover metabolic effects of antiangiogenic therapy in tumors
2016
Tumor heterogeneity at the genetic level has been illustrated by a multitude of studies on the genomics of cancer, but whether tumors can be heterogeneous at the metabolic level is an issue which has been less systematically investigated so far. A burning related question is whether the metabolic features of tumors can change either following natural tumor progression (i.e. in primary tumors versus metastasis) or therapeutic interventions. In this regard, recent findings by independent teams indicate that anti-angiogenic drugs cause metabolic perturbations in tumors as well as metabolic adaptations associated with increased malignancy. Induced metabolic bioluminescence imaging (imBI) is an …
Quantitative Imaging of D-2-Hydroxyglutarate in Selected Histological Tissue Areas by a Novel Bioluminescence Technique
2016
Abstract Patients with malignant gliomas have a poor prognosis with average survival of less than one year. Whereas in other tumor entities the characteristics of tumor metabolism are successfully used for therapeutic approaches, such developments are very rare in brain tumors, notably in gliomas. One metabolic feature characteristic of gliomas, in particular diffuse astrocytomas and oligodendroglial tumors, is the variable content of D-2-hydroxyglutarate (D2HG), a metabolite, which was discovered first in this tumor entity. D2HG is generated in large amounts due to various “gain-of–function” mutations in the isocitrate dehydrogenases IDH-1 and IDH-2. Meanwhile, D2HG has been detected in se…
Uncovering Metabolic Effects of Anti-angiogenic Therapy in Tumors by Induced Metabolic Bioluminescence Imaging
2016
Induced metabolic bioluminescence imaging (imBI) is an imaging technique which enables detection of various metabolites associated with glycolysis in tumor sections. Signals captured by imBI can be used to chart the topographic distribution of lactate, glucose, pyruvate, and ATP and quantify their absolute amount. ImBi can enable us to perform metabolic classification of tumors as well as to detect metabolic changes in the glycolytic pathway associated with certain therapies, such as anti-angiogenic drugs.
Comparison between adenosine triphosphate bioluminescence and aerobic colony count to assess surface sanitation in the hospital environment
2022
Background: Adenosine triphosphate bioluminescence produced by the firefly luciferase has been successfullyintroduced to verify cleaning procedures in the food industry according to the Hazard Analysis Critical Control Pointprogram.Our aim was to evaluate the reliability of bioluminescence as a tool to monitor the effectiveness of sanitation in healthcaresettings, in comparison with the microbiological gold standard.Methods: 614 surfaces of various material were randomly sampled in Policlinico University Hospital units in Palermo,Italy, to detect adenosine triphosphate bioluminescence and aerobic colony count. Linear regression model andPearson correlation coefficient were used to estimate …
Harnessing the potential of noninvasive in vivo preclinical imaging of the immune system: challenges and prospects.
2016
Preclinical imaging has become a powerful method for investigation of in vivo processes such as pharmacokinetics of therapeutic substances and visualization of physiologic and pathophysiological mechanisms. These are important aspects to understand diseases and develop strategies to modify their progression with pharmacologic interventions. One promising intervention is the application of specifically tailored nanoscale particles that modulate the immune system to generate a tumor targeting immune response. In this complex interaction between immunomodulatory therapies, the immune system and malignant disease, imaging methods are expected to play a key role on the way to generate new thera…
Lactate—An Integrative Mirror of Cancer Metabolism
2016
The technique of induced metabolic bioluminescence imaging (imBI) has been developed to obtain a “snapshot” of the momentary metabolic status of biological tissues. Using cryosections of snap-frozen tissue specimens, imBI combines highly specific and sensitive in situ detection of metabolites with a spatial resolution on a microscopic level and with metabolic imaging in relation to tissue histology. Here, we present the application of imBI in human colorectal cancer. Comparing the metabolic information of one biopsy with that of 2 or 3 biopsies per individual cancer, the classification into high versus low lactate tumors, reflecting different glycolytic activities, based on a single biopsy …
Use of Early Life-Stages of Zebrafish to Assess Toxicity of Sediments Contaminated by Organotin Compounds
2016
ABSTRACTThis study examined the response of early life-stages (ELS) of zebrafish to organotin-contaminated sediment from Lake Huruslahti (HL) in Central Finland. A dilution series (0, 10, 33, and 100%) of the native (HL) and the sediment spiked with tributyltin (TBT) determined a dose-response of zebrafish ELS to organotin-contaminated sediment. Sediment elutriates were assessed by bacterial bioluminescence assay and microscopical pathologies of 1–3 days post-fertilization zebrafish (1–3dpfZF). Brain aromatase (cyp19a1b) and tissue vitellogenin (vtg1) were assayed from early-juvenile zebrafish (20dpfZF) exposed to intact sediment. In vivo modulation of cyp19a1b and vtg1 transcripts in 20dpf…
Deep-Sea Bioluminescence Blooms after Dense Water Formation at the Ocean Surface
2013
The deep ocean is the largest and least known ecosystem on Earth. It hosts numerous pelagic organisms, most of which are able to emit light. Here we present a unique data set consisting of a 2.5-year long record of light emission by deep-sea pelagic organisms, measured from December 2007 to June 2010 at the ANTARES underwater neutrino telescope in the deep NW Mediterranean Sea, jointly with synchronous hydrological records. This is the longest continuous time-series of deep-sea bioluminescence ever recorded. Our record reveals several weeks long, seasonal bioluminescence blooms with light intensity up to two orders of magnitude higher than background values, which correlate to changes in th…