scholarly journals Palette of Luciferases: Natural Biotools for New Applications in Biomedicine

Acta Naturae ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 15-27
Author(s):  
A. A. Kotlobay ◽  
Z. M. Kaskova ◽  
I. V. Yampolsky
Keyword(s):  
Atmospheric Oxygen ◽  
Biochemical Properties ◽  
Quantum Yields ◽  
External Irradiation ◽  
Low Molecular Weight ◽  
Non Invasive ◽  
Enzyme Thermostability ◽  
Highly Sensitive ◽  
New Applications ◽  
Optimal Ph

Optoanalytical methods based on using genetically encoded bioluminescent enzymes,luciferases, allow one to obtain highly sensitive signals, are non-invasive, and require no external irradiation. Bioluminescence is based on the chemical reaction of oxidation of a low-molecular-weight substrate (luciferin) by atmospheric oxygen, which is catalyzed by an enzyme (luciferase). Relaxation of the luciferin oxidation product from its excited state is accompanied by a release of a quantum of light, which can be detected as an analytical signal.The ability to express luciferase genes in various heterological systems and high quantum yields of luminescence reactions have made these tools rather popular in biology and medicine. Amongseveral naturally available luciferases, a few have been found to be useful for practicalapplication. Luciferase size, the wavelength of its luminescence maximum, enzyme thermostability, optimal pH of the reaction, and the need for cofactors areparameters that may differ for luciferases from different groups of organisms, and this fact directly affects the choice of the application area for each enzyme. It is quite important to overview the whole range of currently available luciferases based ontheir biochemical properties before choosing one bioluminescent probe suitable for a specific application.

scholarly journals Palette of Luciferases: Natural Biotools for New Applications in Biomedicine

Acta Naturae ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 15-27
Author(s):  
A. A. Kotlobay ◽  
Z. M. Kaskova ◽  
I. V. Yampolsky
Keyword(s):  
Atmospheric Oxygen ◽  
Biochemical Properties ◽  
Quantum Yields ◽  
External Irradiation ◽  
Low Molecular Weight ◽  
Non Invasive ◽  
Enzyme Thermostability ◽  
Highly Sensitive ◽  
New Applications ◽  
Optimal Ph

Optoanalytical methods based on using genetically encoded bioluminescent enzymes,luciferases, allow one to obtain highly sensitive signals, are non-invasive, and require no external irradiation. Bioluminescence is based on the chemical reaction of oxidation of a low-molecular-weight substrate (luciferin) by atmospheric oxygen, which is catalyzed by an enzyme (luciferase). Relaxation of the luciferin oxidation product from its excited state is accompanied by a release of a quantum of light, which can be detected as an analytical signal.The ability to express luciferase genes in various heterological systems and high quantum yields of luminescence reactions have made these tools rather popular in biology and medicine. Amongseveral naturally available luciferases, a few have been found to be useful for practicalapplication. Luciferase size, the wavelength of its luminescence maximum, enzyme thermostability, optimal pH of the reaction, and the need for cofactors areparameters that may differ for luciferases from different groups of organisms, and this fact directly affects the choice of the application area for each enzyme. It is quite important to overview the whole range of currently available luciferases based ontheir biochemical properties before choosing one bioluminescent probe suitable for a specific application.

scholarly journals Difluoroboron β-diketonate polylactic acid oxygen nanosensors for intracellular neuronal imaging

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Meng Zhuang ◽  
Suchitra Joshi ◽  
Huayu Sun ◽  
Tamal Batabyal ◽  
Cassandra L. Fraser ◽  
...  
Keyword(s):  
Neuronal Activity ◽  
Oxygen Sensing ◽  
Brain Slices ◽  
Neuronal Cell ◽  
Quantum Yields ◽  
Poly Lactic Acid ◽  
Neuronal Cultures ◽  
Primary Neuronal Cultures ◽  
Non Invasive ◽  
Mitotracker Red

AbstractCritical for metabolism, oxygen plays an essential role in maintaining the structure and function of neurons. Oxygen sensing is important in common neurological disorders such as strokes, seizures, or neonatal hypoxic–ischemic injuries, which result from an imbalance between metabolic demand and oxygen supply. Phosphorescence quenching by oxygen provides a non-invasive optical method to measure oxygen levels within cells and tissues. Difluoroboron β-diketonates are a family of luminophores with high quantum yields and tunable fluorescence and phosphorescence when embedded in certain rigid matrices such as poly (lactic acid) (PLA). Boron nanoparticles (BNPs) can be fabricated from dye-PLA materials for oxygen mapping in a variety of biological milieu. These dual-emissive nanoparticles have oxygen-insensitive fluorescence, oxygen-sensitive phosphorescence, and rigid matrix all in one, enabling real-time ratiometric oxygen sensing at micron-level spatial and millisecond-level temporal resolution. In this study, BNPs are applied in mouse brain slices to investigate oxygen distributions and neuronal activity. The optical properties and physical stability of BNPs in a biologically relevant buffer were stable. Primary neuronal cultures were labeled by BNPs and the mitochondria membrane probe MitoTracker Red FM. BNPs were taken up by neuronal cell bodies, at dendrites, and at synapses, and the localization of BNPs was consistent with that of MitoTracker Red FM. The brain slices were stained with the BNPs, and the BNPs did not significantly affect the electrophysiological properties of neurons. Oxygen maps were generated in living brain slices where oxygen is found to be mostly consumed by mitochondria near synapses. Finally, the BNPs exhibited excellent response when the conditions varied from normoxic to hypoxic and when the neuronal activity was increased by increasing K+ concentration. This work demonstrates the capability of BNPs as a non-invasive tool in oxygen sensing and could provide fundamental insight into neuronal mechanisms and excitability research.

scholarly journals Role of MRI evaluation in acute secondary inability to walk in children

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
K. H. Sedeek ◽  
K. Aboualfotouh ◽  
S. M. Hassanein ◽  
N. M. Osman ◽  
M. H. Shalaby
Keyword(s):  
Transverse Myelitis ◽  
High Sensitivity ◽  
Acute Disseminated Encephalomyelitis ◽  
Limb Weakness ◽  
Non Invasive ◽  
Highly Sensitive ◽  
Common Causes ◽  
Bilateral Lower Limb ◽  
Severity Of The Disease

Abstract Background Acute bilateral lower limb weakness is a common problem in children which necessitates a rapid method for diagnosis. MRI is a non-invasive imaging technique that produces high-quality images of the internal structure of the brain and spinal cord. Results MRI was very helpful in reaching rapid and prompt diagnosis in children with acute inability to walk. Acute disseminated encephalomyelitis (ADEM), Guillain–Barré syndrome (GBS), and acute transverse myelitis (ATM) were the most common causes in our study. MRI proved to be of high sensitivity in detecting the lesions and reaching the diagnosis in ADEM and GBS; however, there was no significant relation between the lesions’ size, enhancement pattern, and severity of the disease or prognosis, yet in ATM the site of the lesion and number of cord segment affection were significantly related to the severity of the disease and prognosis. Conclusion MRI is a quick tool to reach the diagnosis of children with acute secondary inability to walk, and to eliminate other differential diagnosis which is essential for proper treatment and rapid full recovery. It is highly sensitive in detecting the lesions, their site and size.

scholarly journals Laccases: Versatile Biocatalysts for the Synthesis of Heterocyclic Cores

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3719
Author(s):  
Ana Catarina Sousa ◽  
Lígia O. Martins ◽  
M. Paula Robalo
Keyword(s):  
Membered Ring ◽  
Low Molecular Weight ◽  
Redox Potentials ◽  
Redox Mediators ◽  
Multicopper Oxidases ◽  
Phenothiazine Derivatives ◽  
Ph Values ◽  
Electron Shuttles ◽  
Specific Oxidation ◽  
Optimal Ph

Laccases are multicopper oxidases that have shown a great potential in various biotechnological and green chemistry processes mainly due to their high relative non-specific oxidation of phenols, arylamines and some inorganic metals, and their high redox potentials that can span from 500 to 800 mV vs. SHE. Other advantages of laccases include the use of readily available oxygen as a second substrate, the formation of water as a side-product and no requirement for cofactors. Importantly, addition of low-molecular-weight redox mediators that act as electron shuttles, promoting the oxidation of complex bulky substrates and/or of higher redox potential than the enzymes themselves, can further expand their substrate scope, in the so-called laccase-mediated systems (LMS). Laccase bioprocesses can be designed for efficiency at both acidic and basic conditions since it is known that fungal and bacterial laccases exhibit distinct optimal pH values for the similar phenolic and aromatic amines. This review covers studies on the synthesis of five- and six-membered ring heterocyclic cores, such as benzimidazoles, benzofurans, benzothiazoles, quinazoline and quinazolinone, phenazine, phenoxazine, phenoxazinone and phenothiazine derivatives. The enzymes used and the reaction protocols are briefly outlined, and the mechanistic pathways described.

scholarly journals Identification and mapping of ancient pigments in a Roman Egyptian funerary portrait by application of reflectance and luminescence imaging spectroscopy

2022 ◽  
Vol 10 (1) ◽  
Author(s):  
Roxanne Radpour ◽  
Glenn A. Gates ◽  
Ioanna Kakoulli ◽  
John K. Delaney
Keyword(s):  
Molecular Spectroscopy ◽  
Imaging Spectroscopy ◽  
Chemical Mapping ◽  
Spectral Signatures ◽  
Egyptian Blue ◽  
Non Invasive ◽  
Analytical Protocol ◽  
Linear Unmixing ◽  
New Applications ◽  
Madder Lake

AbstractImaging spectroscopy (IS) is an important tool in the comprehensive technical analysis required of archaeological paintings. The complexity of pigment mixtures, diverse artistic practices and painting technologies, and the often-fragile and weathered nature of these objects render macroscale, non-invasive chemical mapping an essential component of the analytical protocol. Furthermore, the use of pigments such as Egyptian blue and madder lake, featuring diagnostic photoluminescence emission, provides motivation to perform photoluminescence mapping on the macroscale. This work demonstrates and advances new applications of dual-mode imaging spectroscopy and data analysis approaches for ancient painting. Both reflectance (RIS) and luminescence (LIS) modes were utilized for the study of a Roman Egyptian funerary portrait from second century CE Egypt. The first derivative of the RIS image cube was analyzed and found to significantly improve materials separation, identification, and the extent of mapping. Egyptian blue and madder lake were mapped across a decorated surface using their luminescence spectral signatures in the region of 540–1000 nm as endmembers in LIS analyses. Linear unmixing of the LIS endmembers and subsequent derivative analyses resulted in an improved separation and mapping of the luminescence pigments. RIS and LIS studies, combined with complementary, single-spot collection elemental and molecular spectroscopy, were able to successfully characterize the portrait’s painting materials and binding media used by the ancient artist, providing key insight into their material use, stylistic practices, and technological choices.

scholarly journals CECT in Pulmonary Thrombolism

2021 ◽  
pp. 284-293
Author(s):  
Shaha Pramod ◽  
Ragi Skanda ◽  
Bhoite Amol ◽  
Tamboli Asif ◽  
Gautama Amol
Keyword(s):  
Pulmonary Embolism ◽  
Public Health Problem ◽  
Pulmonary Angiography ◽  
High Morbidity ◽  
Major Public Health Problem ◽  
Medical Sciences ◽  
Non Invasive ◽  
Highly Sensitive ◽  
Associated Conditions

Introduction: Pulmonary embolism (PE) is the third most common acute heart disease after myocardial infarction and stroke and is a major public health problem. PE is a disease that has high morbidity and mortality, yet it is challenging to obtain a diagnosis. Objective: The study aims to assess the role of MDCT-PA in the diagnosis of pulmonary embolism, and it's associated conditions in suspected cases of pulmonary embolism. Materials and Methods: The study was conducted in the department of radiology in KRISHNA INSTITUTE OF MEDICAL SCIENCES DEEMED TO BE UNIVERSITY situated in KARAD equipped with a 16 slice MDCT scanner (EMOTION) manufactured by Siemens. Results: Through the study period of one and half year and have met the inclusion criteria, a total of 90 consecutive patients who presented with suspicion of PE were referred for MDCT-PA in the department of radio-diagnosis, Krishna Hospital, Karad. A review of all the cases was done, and the results were presented in the form of tables. Conclusion: Multidetector computed tomography pulmonary angiography can be used to confidently diagnose pulmonary embolism in which it is not contraindicated. MDCT-PA is the investigation of choice because it is a rapid, non-invasive study, highly sensitive and specific.

Postural freezing foretells startle-potentiation in a human fear-conditioning paradigm

2021 ◽  
Author(s):  
Vanessa van Ast ◽  
Floris Klumpers ◽  
Raoul P P P Grasman ◽  
Angelos-Miltiadis Krypotos ◽  
Karin Roelofs
Keyword(s):  
Fear Conditioning ◽  
Real Life ◽  
Conditioning Paradigm ◽  
Non Invasive ◽  
Startle Magnitude ◽  
Highly Sensitive ◽  
Human Conditioning ◽  
Conditioned Freezing ◽  
Fear And Anxiety ◽  
Active Preparation

Freezing to impending threat is a core defensive response. It has been studied primarily using fear-conditioning in non-human animals, thwarting advances in translational human anxiety-research. Here we examine postural freezing as a human conditioning-index for translational anxiety-research. We show (n=28) that human freezing is highly sensitive to fear-conditioning, generalizes to ambiguous contexts, and amplifies with threat-imminence. Intriguingly, stronger parasympathetically-driven freezing under threat, but not sympathetically-mediated skin conductance, predicts subsequent startle magnitude. These results demonstrate that humans show fear-conditioned animal-like freezing responses, known to aid in active preparation for unexpected attack, and that freezing captures real-life anxiety-expression. Conditioned freezing offers a promising new, non-invasive, and continuous, readout for human fear-conditioning, paving the way for future translational studies into human fear and anxiety.

Infrared Thermography as a Means of Monitoring and Preventing Sports Injuries

2017 ◽  
pp. 165-198
Author(s):  
Manuel Sillero-Quintana ◽  
Pedro M. Gomez-Carmona ◽  
Ismael Fernández-Cuevas
Keyword(s):  
Infrared Thermography ◽  
Thermal Equilibrium ◽  
Sports Injuries ◽  
Low Cost ◽  
Professional Sports ◽  
Recovery Process ◽  
Non Invasive ◽  
Healthy State ◽  
New Applications ◽  
Contact Recording

Sports injuries are one of the most important problems in sports. Moreover, professional sports injuries lead to a difficult recovery process for the athletes, reduced athletic performance, and large economic costs. Infrared thermography (IRT) is a safe, non-invasive and low-cost technique that allows for the rapid and non-contact recording of Skin Temperature (Tsk). Recent research results have demonstrated new applications for this technique; among them, the monitoring and prevention of sports injuries appears to be one of the most interesting applications. Although IRT is not as objective as other methods, it may be sufficiently accurate and reliable as a complementary tool considering the theory that musculoskeletal structures should be in thermal equilibrium when in a healthy state. Therefore, the main contribution of IRT is to help identify an injury before it occurs, providing an opportunity for preventative action.

Infrared Thermography as a Means of Monitoring and Preventing Sports Injuries

2021 ◽  
pp. 832-865
Author(s):  
Manuel Sillero-Quintana ◽  
Pedro M. Gomez-Carmona ◽  
Ismael Fernández-Cuevas
Keyword(s):  
Infrared Thermography ◽  
Thermal Equilibrium ◽  
Sports Injuries ◽  
Low Cost ◽  
Professional Sports ◽  
Recovery Process ◽  
Non Invasive ◽  
Healthy State ◽  
New Applications ◽  
Contact Recording

Sports injuries are one of the most important problems in sports. Moreover, professional sports injuries lead to a difficult recovery process for the athletes, reduced athletic performance, and large economic costs. Infrared thermography (IRT) is a safe, non-invasive and low-cost technique that allows for the rapid and non-contact recording of Skin Temperature (Tsk). Recent research results have demonstrated new applications for this technique; among them, the monitoring and prevention of sports injuries appears to be one of the most interesting applications. Although IRT is not as objective as other methods, it may be sufficiently accurate and reliable as a complementary tool considering the theory that musculoskeletal structures should be in thermal equilibrium when in a healthy state. Therefore, the main contribution of IRT is to help identify an injury before it occurs, providing an opportunity for preventative action.

scholarly journals Ultrasound - first imaging modality in the detection of parathyroid adenomas

2008 ◽  
Vol 12 (3) ◽  
pp. 64 ◽  
Author(s):  
R Ahmed ◽  
N Khan ◽  
S Ellemdin ◽  
K Gayaparsad
Keyword(s):  
Nuclear Medicine ◽  
High Resolution ◽  
Gold Standard ◽  
Imaging Modality ◽  
Non Invasive ◽  
Highly Sensitive ◽  
Parathyroid Adenomas ◽  
Thyroid Adenomas ◽  
Invasive Method ◽  
Ultrasound Features

Abstract We present a series of 12 patients in whom the typical ultrasound features of parathyroid adenomas were accurately demonstrated. High resolution ultrasound [in experienced hands] is a highly sensitive accurate, safe and non invasive method of localizing parathyroid adenomas especially in patients with typically located glands and an absence of thyroid pathology. Our aim was to compare ultrasound with nuclear medicine as an imaging gold standard in patients with thyroid adenomas.

Sign in / Sign up

Export Citation Format

Share Document