A photoprotein isolated from the bioluminescent jellyfish Aequorea. It emits visible light by an intramolecular reaction when a trace amount of calcium ion is added. The light-emitting moiety in the bioluminescence reaction is believed to be 2-amino-3-benzyl-5-(p-hydroxyphenyl)pyrazine (AF-350).
The class of true jellyfish, in the phylum CNIDARIA. They are mostly free-swimming marine organisms that go through five stages in their life cycle and exhibit two body forms: polyp and medusa.
Techniques used for determining the values of photometric parameters of light resulting from LUMINESCENCE.
Semidomesticated variety of European polecat much used for hunting RODENTS and/or RABBITS and as a laboratory animal. It is in the subfamily Mustelinae, family MUSTELIDAE.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
A class of Arthropoda that includes SPIDERS; TICKS; MITES; and SCORPIONS.
Emission of LIGHT when ELECTRONS return to the electronic ground state from an excited state and lose the energy as PHOTONS. It is sometimes called cool light in contrast to INCANDESCENCE. LUMINESCENT MEASUREMENTS take advantage of this type of light emitted from LUMINESCENT AGENTS.
Proteins which are involved in the phenomenon of light emission in living systems. Included are the "enzymatic" and "non-enzymatic" types of system with or without the presence of oxygen or co-factors.
A phylum of radially symmetrical invertebrates characterized by possession of stinging cells called nematocysts. It includes the classes ANTHOZOA; CUBOZOA; HYDROZOA, and SCYPHOZOA. Members carry CNIDARIAN VENOMS.
A superorder of marine CRUSTACEA, free swimming in the larval state, but permanently fixed as adults. There are some 800 described species, grouped in several genera, and comprising of two major orders of barnacles: stalked (Pedunculata) and sessile (Sessilia).
Conical muscular projections from the walls of the cardiac ventricles, attached to the cusps of the atrioventricular valves by the chordae tendineae.
An order of MAMMALS, usually flesh eaters with appropriate dentition. Suborders include the terrestrial carnivores Fissipedia, and the aquatic carnivores PINNIPEDIA.
The protein components of a number of complexes, such as enzymes (APOENZYMES), ferritin (APOFERRITINS), or lipoproteins (APOLIPOPROTEINS).
An adrenergic-beta-2 antagonist that has been used for cardiac arrhythmia, angina pectoris, hypertension, glaucoma, and as an antithrombotic.
Compound such as LUMINESCENT PROTEINS that cause or emit light (PHYSICAL LUMINESCENCE).
A methylxanthine naturally occurring in some beverages and also used as a pharmacological agent. Caffeine's most notable pharmacological effect is as a central nervous system stimulant, increasing alertness and producing agitation. It also relaxes SMOOTH MUSCLE, stimulates CARDIAC MUSCLE, stimulates DIURESIS, and appears to be useful in the treatment of some types of headache. Several cellular actions of caffeine have been observed, but it is not entirely clear how each contributes to its pharmacological profile. Among the most important are inhibition of cyclic nucleotide PHOSPHODIESTERASES, antagonism of ADENOSINE RECEPTORS, and modulation of intracellular calcium handling.
3 beta,5,14-Trihydroxy-19-oxo-5 beta-card-20(22)-enolide. The aglycone cardioactive agent isolated from Strophanthus Kombe, S. gratus and other species; it is a very toxic material formerly used as digitalis. Synonyms: Apocymarin; Corchorin; Cynotoxin; Corchorgenin.
Pyrazines are heterocyclic organic compounds containing a six-membered ring with two nitrogen atoms at opposite positions, often responsible for the characteristic flavors and aromas found in various foods, beverages, and some biological systems, but they do not have a direct medical definition as they are not a drug, treatment, or a significant component of human physiology or pathology.
A benzothaizole which is oxidized by LUCIFERASES, FIREFLY to cause emission of light (LUMINESCENCE).
Metallochrome indicator that changes color when complexed to the calcium ion under physiological conditions. It is used to measure local calcium ion concentrations in vivo.
A chelating agent relatively more specific for calcium and less toxic than EDETIC ACID.
Contractile activity of the MYOCARDIUM.
A methylpyrrole-carboxylate from RYANIA that disrupts the RYANODINE RECEPTOR CALCIUM RELEASE CHANNEL to modify CALCIUM release from SARCOPLASMIC RETICULUM resulting in alteration of MUSCLE CONTRACTION. It was previously used in INSECTICIDES. It is used experimentally in conjunction with THAPSIGARGIN and other inhibitors of CALCIUM ATPASE uptake of calcium into SARCOPLASMIC RETICULUM.

Intracellular trafficking pathways in the assembly of connexins into gap junctions. (1/417)

Trafficking pathways underlying the assembly of connexins into gap junctions were examined using living COS-7 cells expressing a range of connexin-aequorin (Cx-Aeq) chimeras. By measuring the chemiluminescence of the aequorin fusion partner, the translocation of oligomerized connexins from intracellular stores to the plasma membrane was shown to occur at different rates that depended on the connexin isoform. Treatment of COS-7 cells expressing Cx32-Aeq and Cx43-Aeq with brefeldin A inhibited the movement of these chimera to the plasma membrane by 84 +/- 4 and 88 +/- 4%, respectively. Nocodazole treatment of the cells expressing Cx32-Aeq and Cx43-Aeq produced 29 +/- 16 and 4 +/- 7% inhibition, respectively. In contrast, the transport of Cx26 to the plasma membrane, studied using a construct (Cx26/43T-Aeq) in which the short cytoplasmic carboxyl-terminal tail of Cx26 was replaced with the extended carboxyl terminus of Cx43, was inhibited 89 +/- 5% by nocodazole and was minimally affected by exposure of cells to brefeldin A (17 +/-11%). The transfer of Lucifer yellow across gap junctions between cells expressing wild-type Cx32, Cx43, and the corresponding Cx32-Aeq and Cx43-Aeq chimeras was reduced by nocodazole treatment and abolished by brefeldin A treatment. However, the extent of dye coupling between cells expressing wild-type Cx26 or the Cx26/43T-Aeq chimeras was not significantly affected by brefeldin A treatment, but after nocodazole treatment, transfer of dye to neighboring cells was greatly reduced. These contrasting effects of brefeldin A and nocodazole on the trafficking properties and intercellular dye transfer are interpreted to suggest that two pathways contribute to the routing of connexins to the gap junction.  (+info)

Reactive oxygen metabolites increase mitochondrial calcium in endothelial cells: implication of the Ca2+/Na+ exchanger. (2/417)

In endothelial cells, a bolus of hydrogen peroxide (H2O2) or oxygen metabolites generated by hypoxanthine-xanthine oxidase (HX-XO) increased the mitochondrial calcium concentration [Ca2+]m. Both agents caused a biphasic increase in [Ca2+]m which was preceded by a rise in cytosolic free calcium concentration [Ca2+]c (18 and 6 seconds for H2O2 and HX-XO, respectively). The peak and plateau elevations of [Ca2+] were consistently higher in the mitochondrial matrix than in the cytosol. In Ca2+-free/EGTA medium, the plateau phase of elevated [Ca2+] evoked by H2O2 due to capacitative Ca2+ influx was abolished in the cytosol, but was maintained in the mitochondria. In contrast to H2O2 and HX-XO, ATP which binds the P2Y purinoceptors induced an increase in [Ca2+]m that was similar to that of [Ca2+]c. When cells were first stimulated with inositol 1,4, 5-trisphosphate-generating agonists or the Ca2+-ATPase inhibitor cyclopiazonic acid (CPA), subsequent addition of H2O2 did not affect [Ca2+]c, but still caused an elevation of [Ca2+]m. Moreover, the specific inhibitor of the mitochondrial Ca2+/Na+ exchanger, 7-chloro-3,5-dihydro-5-phenyl-1H-4.1-benzothiazepine-2-on (CGP37157), did not potentiate the effects of H2O2 and HX-XO on [Ca2+]m, while causing a marked increase in the peak [Ca2+]m and a significant attenuation of the rate of [Ca2+]m efflux upon addition of histamine or CPA. In permeabilized cells, H2O2 mimicked the effects of CGP37157 causing an increase in the basal level of matrix free Ca2+ and decreased efflux. Dissipation of the electrochemical proton gradient by carbonylcyanide p-(trifluoromethoxy) phenylhydrazone (FCCP), and blocade of the Ca2+ uptake by ruthenium red prevented [Ca2+]m increases evoked by H2O2. These results demonstrate that the H2O2-induced elevation in [Ca2+]m results from a transfer of Ca2+ secondary to increased [Ca2+]c, and an inhibition of the Ca2+/Na+ electroneutral exchanger of the mitochondria.  (+info)

Functional effects of endothelin and regulation of endothelin receptors in isolated human nonfailing and failing myocardium. (3/417)

BACKGROUND: An activated endothelin (ET) system may be of pathophysiological relevance in human heart failure. We characterized the functional effects of ET-1, ET receptors, and ET-1 peptide concentration in left ventricular myocardium from 10 nonfailing hearts (NF) and 27 hearts in end-stage failure due to idiopathic dilative cardiomyopathy (DCM). METHODS AND RESULTS: Inotropic effects were characterized in isolated muscle strips (1 Hz; 37 degrees C). ET-1 0.0001 to 0.3 micromol/L significantly (P<0.05) increased twitch force by maximally 59+/-10% in NF and by 36+/-11% in DCM (P<0.05 versus NF). Preincubation with propranolol 1 micromol/L and prazosin 0.1 micromol/L did not affect the response to ET-1, but the mixed ET receptor antagonist bosentan and the ETA receptor antagonist BQ-123 shifted the concentration-response curves for ET-1 rightward. The ETB receptor agonist sarafotoxin S6c 0.001 to 0.3 micromol/L had no functional effects. The inotropic response to ET-1 was not associated with increased intracellular Ca2+ transients, as assessed in aequorin-loaded muscle strips. ET receptor density (Bmax; radioligand binding) was 62.5+/-12.5 fmol/mg protein in NF and 122. 4+/-24.3 fmol/mg protein in DCM (P<0.05 versus NF). The increase in Bmax in DCM resulted from an increase in ETA receptors without change in ETB receptors. ET-1 peptide concentration (radioimmunoassay) was higher in DCM than in NF (14 447+/-2232 versus 4541+/-1340 pg/mg protein, P<0.05). CONCLUSIONS: ET-1 exerts inotropic effects in human myocardium through ETA receptor-mediated increases in myofibrillar Ca2+ responsiveness. In DCM, functional effects of ET-1 are attenuated, but ETA receptor density and ET-1 peptide concentration are increased, indicating an activated local cardiac ET system and possibly a reduced postreceptor signaling efficiency.  (+info)

Secretagogues modulate the calcium concentration in the endoplasmic reticulum of insulin-secreting cells. Studies in aequorin-expressing intact and permeabilized ins-1 cells. (4/417)

The precise regulation of the Ca2+ concentration in the endoplasmic reticulum ([Ca2+]er) is important for protein processing and signal transduction. In the pancreatic beta-cell, dysregulation of [Ca2+]er may cause impaired insulin secretion. The Ca2+-sensitive photoprotein aequorin mutated to lower its Ca2+ affinity was stably expressed in the endoplasmic reticulum (ER) of rat insulinoma INS-1 cells. The steady state [Ca2+]er was 267 +/- 9 microM. Both the Ca2+-ATPase inhibitor cyclopiazonic acid and 4-chloro-m-cresol, an activator of ryanodine receptors, caused an almost complete emptying of ER Ca2+. The inositol 1,4,5-trisphosphate generating agonists, carbachol, and ATP, reduced [Ca2+]er by 20-25%. Insulin secretagogues that raise cytosolic [Ca2+] by membrane depolarization increased [Ca2+]er in the potency order K+ >> glucose > leucine, paralleling their actions in the cytosolic compartment. Glucose, which augmented [Ca2+]er by about 25%, potentiated the Ca2+-mobilizing effect of carbachol, explaining the corresponding observation in cytosolic [Ca2+]. The filling of ER Ca2+ by glucose is not directly mediated by ATP production as shown by the continuous monitoring of cytosolic ATP in luciferase expressing cells. Both glucose and K+ increase [Ca2+]er, but only the former generated whereas the latter consumed ATP. Nonetheless, drastic lowering of cellular ATP with a mitochondrial uncoupler resulted in a marked decrease in [Ca2+]er, emphasizing the requirement for mitochondrially derived ATP above a critical threshold concentration. Using alpha-toxin permeabilized cells in the presence of ATP, glucose 6-phosphate did not change [Ca2+]er, invalidating the hypothesis that glucose acts through this metabolite. Therefore, insulin secretagogues that primarily stimulate Ca2+ influx, elevate [Ca2+]er to ensure beta-cell homeostasis.  (+info)

Reactive oxygen species activate a Ca2+-dependent cell death pathway in the unicellular organism Trypanosoma brucei brucei. (5/417)

Here we examine a cell death process induced by reactive oxygen species (ROS) in the haemoflagellate Trypanosoma brucei brucei. Ca2+ distribution in cellular compartments was measured with stable transformants expressing aequorin targeted to the cytosol, nucleus or mitochondrion. Within 1.5 h of ROS production, mitochondrial Ca2+ transport was impaired and the Ca2+ barrier between the nuclear envelope and cytosol was disrupted. Consequently the mitochondrion did not accumulate Ca2+ efficiently in response to an extracellular stimulus, and excess Ca2+ accumulated in the nucleus. The terminal transferase deoxytidyl uridine end labelling assay revealed that, 5 h after treatment with ROS, extensive fragmentation of nuclear DNA occurred in over 90% of the cells. Permeability changes in the plasma membrane did not occur until an additional 2 h had elapsed. The intracellular Ca2+ buffer, EGTA acetoxymethyl ester, prevented DNA fragmentation and prolonged the onset of changes in cell permeability. Despite some similarities to apoptosis, nuclease activation was not a consequence of caspase 3, caspase 1, calpain, serine protease, cysteine protease or proteasome activity. Moreover, trypanosomes expressing mouse Bcl-2 were not protected from ROS even though protection from mitochondrial dysfunction and ROS have been reported for mammalian cells. Overall, these results demonstrate that Ca2+ pathways can induce pathology in trypanosomes, although the specific proteins involved might be distinct from those in metazoans.  (+info)

The vacuolar Ca2+/H+ exchanger Vcx1p/Hum1p tightly controls cytosolic Ca2+ levels in S. cerevisiae. (6/417)

It is well established that the vacuole plays an important role in the cellular adaptation to growth in the presence of elevated extracellular Ca2+ concentrations in Saccharomyces cerevisiae. The Ca2+ ATPase Pmc1p and the Ca2+/H+ exchanger Vcx1p/Hum1p have been shown to facilitate Ca2+ sequestration into the vacuole. However, the distinct physiological roles of these two vacuolar Ca2+ transporters remain uncertain. Here we show that Vcx1p can rapidly sequester a sudden pulse of cytosolic Ca2+ into the vacuole, while Pmc1p carries out this function much less efficiently. This finding is consistent with the postulated role of Vcx1p as a high capacity, low affinity Ca2+ transporter and suggests that Vcx1p may act to attenuate the propagation of Ca2+ signals in this organism.  (+info)

Differential pharmacological properties and signal transduction of the sphingosine 1-phosphate receptors EDG-1, EDG-3, and EDG-5. (7/417)

Sphingosine 1-phosphate (SPP) is a potent lipid mediator released upon cellular activation. In this report, pharmacological properties of the three G-protein-coupled receptors (GPCRs) for SPP, EDG-1, -3, and -5 are characterized using a Xenopus oocyte expression system, which lacks endogenous SPP receptors. Microinjection of the EDG-3 and EDG-5 but not EDG-1 mRNA conferred SPP-responsive intracellular calcium transients; however, the EDG-5 response was quantitatively much less. Co-expression of EDG-1 receptor with the chimeric Galphaqi protein conferred SPP responsiveness. Galphaqi or Galphaq co-injection also potentiated the EDG-5 and EDG-3 mediated responses to SPP. These data suggest that SPP receptors couple differentially to the Gq and Gi pathway. All three GPCRs were also activated by sphingosylphosphorylcholine, albeit at higher concentrations. None of the other related sphingolipids tested stimulated or blocked SPP-induced calcium responses. However, suramin, a polycyclic anionic compound, selectively antagonized SPP-activated calcium transients in EDG-3 expressing oocytes with an IC50 of 22 microM, suggesting that it is an antagonist selective for the EDG-3 GPCR isotype. We conclude that the three SPP receptors signal differentially by coupling to different G-proteins. Furthermore, because only EDG-3 was antagonized by suramin, variations in receptor structure may determine differences in antagonist selectivity. This property may be exploited to synthesize receptor subtype-specific antagonists.  (+info)

Measurement of perimitochondrial Ca2+ concentration in bovine adrenal glomerulosa cells with aequorin targeted to the outer mitochondrial membrane. (8/417)

Microdomains of high cytosolic free Ca(2+) concentration in the proximity of mitochondria might have an important role in the stimulation of steroidogenesis in bovine adrenal glomerulosa cells. In the present study we have investigated local changes of free Ca(2+) concentration near the outer mitochondrial membrane ([Ca(2+)](om)) under stimulation with angiotensin II (Ang II) and K(+). Glomerulosa cells in primary culture were transfected with a recombinant cDNA encoding the N-terminal region of the human translocase protein 20 of the outer mitochondrial membrane, in frame with the Ca(2+)-sensitive photoprotein aequorin. This chimaeric aequorin (TomAeq) was associated with mitochondria-enriched subcellular fractions of transfected COS-7 cells and was susceptible to proteinase K, showing that it was targeted to the outer mitochondrial membrane, facing the cytosolic space. In bovine adrenal glomerulosa cells transfected with TomAeq cDNA, Ang II induced a transient [Ca(2+)](om) peak reaching 1.42+/-0.28 microM, which decreased immediately to the basal resting value. The peak response to Ang II was strikingly lower than the peak response of mitochondrial free Ca(2+) concentration, which increased to 5.4+/-1.2 microM. The smaller response of [Ca(2+)](om) to Ang II compared with the elevated matrix response did not result from buffering effects of the organelle, from altered mechanisms of intramitochondrial Ca(2+) transport or from differences in the affinity of the chimaeric aequorins for Ca(2+). This approach has allowed us to follow perimitochondrial Ca(2+) homeostasis in bovine glomerulosa cells under stimulation with Ca(2+)-mobilizing agonists and to reveal a strong gradient of Ca(2+) concentration between the mitochondrial matrix and the immediate environment of the organelle.  (+info)

Aequorin is a bioluminescent protein found in certain jellyfish species, such as Aequorea victoria. It emits light when it undergoes a conformational change in the presence of calcium ions (Ca^2+^). This property makes aequorin a valuable tool in studying intracellular calcium levels and dynamics in various biological systems, including cells and model organisms.

The reaction that leads to light emission involves the binding of Ca^2+^ ions to aequorin, which then triggers the oxidation of coelenterazine, a chromophore molecule, to produce coelenteramide along with the release of energy in the form of blue light (approximately 469 nm). The intensity of the light emitted is directly proportional to the concentration of Ca^2+^ ions, allowing researchers to monitor and measure calcium levels in real-time.

Aequorin has been widely used in various research fields, such as neuroscience, cardiology, and cell biology, to investigate calcium signaling pathways and their roles in numerous physiological processes and diseases. Additionally, aequorin-based biosensors have been developed to study calcium dynamics in vivo, providing valuable insights into the complex interplay between calcium homeostasis and cellular functions.

Scyphozoa is a class in the phylum Cnidaria, which includes true jellyfish. Scyphozoans are free-swimming marine animals characterized by a medusa-like stage in their life cycle that is dominant and persistent. They have a bell-shaped body with tentacles hanging from the margin of the bell. The tentacles contain cnidocytes, specialized cells that deliver venom through nematocysts to capture prey. Scyphozoans have a simple nervous system and lack a brain or centralized nervous system. They also have a radial symmetry, meaning their body parts are arranged around a central axis. Some examples of Scyphozoa include the sea nettle, moon jelly, and lion's mane jellyfish.

Luminescent measurements refer to the quantitative assessment of the emission of light from a substance that has been excited, typically through some form of energy input such as electrical energy or radiation. In the context of medical diagnostics and research, luminescent measurements can be used in various applications, including bioluminescence imaging, which is used to study biological processes at the cellular and molecular level.

Bioluminescence occurs when a chemical reaction produces light within a living organism, often through the action of enzymes such as luciferase. By introducing a luciferase gene into cells or organisms, researchers can use bioluminescent measurements to track cellular processes and monitor gene expression in real time.

Luminescent measurements may also be used in medical research to study the properties of materials used in medical devices, such as LEDs or optical fibers, or to develop new diagnostic tools based on light-emitting nanoparticles or other luminescent materials.

In summary, luminescent measurements are a valuable tool in medical research and diagnostics, providing a non-invasive way to study biological processes and develop new technologies for disease detection and treatment.

A ferret is a domesticated mammal that belongs to the weasel family, Mustelidae. The scientific name for the common ferret is Mustela putorius furo. Ferrets are native to Europe and have been kept as pets for thousands of years due to their playful and curious nature. They are small animals, typically measuring between 13-20 inches in length, including their tail, and weighing between 1.5-4 pounds.

Ferrets have a slender body with short legs, a long neck, and a pointed snout. They have a thick coat of fur that can vary in color from white to black, with many different patterns in between. Ferrets are known for their high level of activity and intelligence, and they require regular exercise and mental stimulation to stay healthy and happy.

Ferrets are obligate carnivores, which means that they require a diet that is high in protein and low in carbohydrates. They have a unique digestive system that allows them to absorb nutrients efficiently from their food, but it also means that they are prone to certain health problems if they do not receive proper nutrition.

Ferrets are social animals and typically live in groups. They communicate with each other using a variety of vocalizations, including barks, chirps, and purrs. Ferrets can be trained to use a litter box and can learn to perform simple tricks. With proper care and attention, ferrets can make loving and entertaining pets.

Calcium is an essential mineral that is vital for various physiological processes in the human body. The medical definition of calcium is as follows:

Calcium (Ca2+) is a crucial cation and the most abundant mineral in the human body, with approximately 99% of it found in bones and teeth. It plays a vital role in maintaining structural integrity, nerve impulse transmission, muscle contraction, hormonal secretion, blood coagulation, and enzyme activation.

Calcium homeostasis is tightly regulated through the interplay of several hormones, including parathyroid hormone (PTH), calcitonin, and vitamin D. Dietary calcium intake, absorption, and excretion are also critical factors in maintaining optimal calcium levels in the body.

Hypocalcemia refers to low serum calcium levels, while hypercalcemia indicates high serum calcium levels. Both conditions can have detrimental effects on various organ systems and require medical intervention to correct.

Arachnida is a class of joint-legged invertebrate animals that includes spiders, scorpions, mites, and ticks. They are characterized by having two main body segments (the cephalothorax and the abdomen), eight legs, and simple eyes. Most arachnids produce silk, which they use for various purposes such as capturing prey or building shelters.

Arachnids are arthropods, a group that also includes insects, crustaceans, and other related animals. They are found worldwide in diverse habitats, ranging from forests and grasslands to deserts and caves. Many arachnids are predators, feeding on insects and other small animals. Some species are parasites, living on the blood or tissue of other organisms.

Arachnids have a hard exoskeleton made of chitin, which provides protection and support for their soft internal organs. They molt periodically to grow and replace damaged body parts. Arachnids also have a complex reproductive system that involves the transfer of sperm from the male to the female through specialized structures called pedipalps.

While some arachnids are harmless or even beneficial to humans, others can be dangerous or pests. For example, spider bites can cause painful reactions and in rare cases, death. Ticks and mites can transmit diseases such as Lyme disease and scrub typhus. Scorpions can deliver venomous stings that can be fatal to humans. Despite these risks, arachnids play important roles in ecosystems, controlling pests and contributing to nutrient cycling.

Luminescence is not a term that has a specific medical definition. However, in general terms, luminescence refers to the emission of light by a substance that has absorbed energy. This phenomenon can occur in some medical contexts, such as in medical imaging techniques like bioluminescence imaging (BLI) and chemiluminescence immunoassays (CLIA).

In BLI, genetically modified organisms or cells are used to produce light at specific wavelengths that can be detected and measured. This technique is often used in preclinical research to study biological processes such as gene expression, cell proliferation, and metastasis.

In CLIA, an enzymatic reaction produces light that is used to detect and quantify the presence of a specific analyte or target molecule. This technique is commonly used in clinical laboratories for the detection of various biomarkers, such as hormones, drugs, and infectious agents.

Therefore, while luminescence is not a medical term per se, it has important applications in medical research and diagnostics.

Luminescent proteins are a type of protein that emit light through a chemical reaction, rather than by absorbing and re-emitting light like fluorescent proteins. This process is called bioluminescence. The light emitted by luminescent proteins is often used in scientific research as a way to visualize and track biological processes within cells and organisms.

One of the most well-known luminescent proteins is Green Fluorescent Protein (GFP), which was originally isolated from jellyfish. However, GFP is actually a fluorescent protein, not a luminescent one. A true example of a luminescent protein is the enzyme luciferase, which is found in fireflies and other bioluminescent organisms. When luciferase reacts with its substrate, luciferin, it produces light through a process called oxidation.

Luminescent proteins have many applications in research, including as reporters for gene expression, as markers for protein-protein interactions, and as tools for studying the dynamics of cellular processes. They are also used in medical imaging and diagnostics, as well as in the development of new therapies.

Cnidaria is a phylum of aquatic animals that includes jellyfish, sea anemones, hydra, and corals. They are characterized by the presence of specialized stinging cells called cnidocytes, which they use for defense and capturing prey. Cnidarians have a simple body organization with two basic forms: polyps, which are typically cylindrical and attached to a substrate; and medusae, which are free-swimming and bell-shaped. Some species can exist in both forms during their life cycle.

Cnidarians have no true organs or organ systems, but they do have a unique tissue arrangement with two main layers: an outer epidermis and an inner gastrodermis, separated by a jelly-like mesoglea. They have a digestive cavity called the coelenteron, where they absorb nutrients after capturing and digesting prey. Cnidarians reproduce both sexually and asexually, with some species exhibiting complex life cycles involving multiple forms and reproductive strategies.

"Thoracica" is not a term that has a widely accepted medical definition. However, in the field of anatomy and zoology, "Thoracica" is used to refer to a superorder of small, marine animals known as barnacles, which attach themselves permanently to rocks, whales, and other surfaces. The thoracican barnacles have a unique body structure, with their heads enclosed in a shell and their legs extended through an operculum (a trapdoor-like structure) to filter food from the water.

If you meant to ask about a different medical or scientific term, please let me know and I will be happy to help.

Papillary muscles are specialized muscle structures located in the heart, specifically in the ventricles (the lower chambers of the heart). They are attached to the tricuspid and mitral valves' leaflets via tendinous cords, also known as chordae tendineae. The main function of papillary muscles is to prevent the backflow of blood during contraction by providing tension to the valve leaflets through these tendinous cords.

There are two sets of papillary muscles in the heart:

1. Anterior and posterior papillary muscles in the left ventricle, which are attached to the mitral (bicuspid) valve.
2. Three smaller papillary muscles in the right ventricle, which are attached to the tricuspid valve.

These muscle structures play a crucial role in maintaining proper blood flow through the heart and ensuring efficient cardiac function.

Carnivora is an order of mammals that consists of animals whose primary diet consists of flesh. The term "Carnivora" comes from the Latin words "caro", meaning flesh, and "vorare", meaning to devour. This order includes a wide variety of species, ranging from large predators such as lions, tigers, and bears, to smaller animals such as weasels, otters, and raccoons.

While members of the Carnivora order are often referred to as "carnivores," it is important to note that not all members exclusively eat meat. Some species, such as raccoons and bears, have an omnivorous diet that includes both plants and animals. Additionally, some species within this order have evolved specialized adaptations for their specific diets, such as the elongated canines and carnassial teeth of felids (cats) and canids (dogs), which are adapted for tearing and shearing meat.

Overall, the medical definition of Carnivora refers to an order of mammals that have a diet primarily consisting of flesh, although not all members exclusively eat meat.

Apoproteins are the protein components of lipoprotein complexes, which are responsible for transporting fat molecules, such as cholesterol and triglycerides, throughout the body. Apoproteins play a crucial role in the metabolism of lipids by acting as recognition signals that allow lipoproteins to interact with specific receptors on cell surfaces.

There are several different types of apoproteins, each with distinct functions. For example, apolipoprotein A-1 (apoA-1) is the major protein component of high-density lipoproteins (HDL), which are responsible for transporting excess cholesterol from tissues to the liver for excretion. Apolipoprotein B (apoB) is a large apoprotein found in low-density lipoproteins (LDL), very low-density lipoproteins (VLDL), and lipoprotein(a). ApoB plays a critical role in the assembly and secretion of VLDL from the liver, and it also mediates the uptake of LDL by cells.

Abnormalities in apoprotein levels or function can contribute to the development of various diseases, including cardiovascular disease, diabetes, and Alzheimer's disease. Therefore, measuring apoprotein levels in the blood can provide valuable information for diagnosing and monitoring these conditions.

Bupranolol is a beta-blocker medication that is primarily used to treat high blood pressure, angina (chest pain), and certain types of irregular heartbeats. It works by blocking the action of certain natural substances in your body, such as epinephrine, that affect the heart and blood vessels. This helps to reduce heart rate, lower blood pressure, and improve blood flow, which can help prevent heart attacks and strokes.

Bupranolol may also be used for other purposes, such as preventing migraines or treating anxiety disorders. It is available in immediate-release and extended-release tablets, and the dosage may vary depending on the specific condition being treated. As with any medication, bupranolol can have side effects, including dizziness, fatigue, and gastrointestinal symptoms. It is important to follow your doctor's instructions carefully when taking this medication and to report any unusual or bothersome side effects promptly.

Luminescent agents, also known as optical imaging agents or fluorescent contrast agents, are substances that emit light upon excitation with external energy sources such as ultraviolet or visible light. In the medical field, these agents are often used in diagnostic and research applications, particularly in medical imaging techniques like fluorescence imaging and bioluminescence imaging.

Luminescent agents can be divided into two main categories: organic and inorganic. Organic luminescent agents include small molecules, dyes, and proteins such as green fluorescent protein (GFP), while inorganic luminescent agents include nanoparticles like quantum dots and upconversion nanoparticles.

These agents are used to enhance the contrast between healthy and diseased tissues or cells, allowing for better visualization of specific structures or processes within the body. They have been used in various medical applications such as cancer detection, atherosclerosis imaging, stem cell tracking, and gene expression analysis. However, it is important to note that the use of luminescent agents in medical imaging requires careful consideration of their potential toxicity, biocompatibility, and pharmacokinetics.

Caffeine is a central nervous system stimulant that occurs naturally in the leaves, seeds, or fruits of some plants. It can also be produced artificially and added to various products, such as food, drinks, and medications. Caffeine has a number of effects on the body, including increasing alertness, improving mood, and boosting energy levels.

In small doses, caffeine is generally considered safe for most people. However, consuming large amounts of caffeine can lead to negative side effects, such as restlessness, insomnia, rapid heart rate, and increased blood pressure. It is also possible to become dependent on caffeine, and withdrawal symptoms can occur if consumption is suddenly stopped.

Caffeine is found in a variety of products, including coffee, tea, chocolate, energy drinks, and some medications. The amount of caffeine in these products can vary widely, so it is important to pay attention to serving sizes and labels to avoid consuming too much.

Strophanthidin is not a commonly used medical term, but it is a chemical compound that comes from the seeds of certain plants in the strokehantus family. It's a cardiac glycoside, meaning it has a toxic effect on the heart muscle and can affect its rhythm. In the past, it was used as a medication to treat heart failure and arrhythmias, but it has largely been replaced by other drugs that are safer and more effective.

In modern medical practice, Strophanthidin is not typically used clinically due to its narrow therapeutic index, potential for toxicity, and the availability of safer alternatives. It's important to note that the use of Strophanthidin or any other cardiac glycoside should be under the close supervision of a healthcare professional.

I'm sorry for any confusion, but "pyrazines" is not a term commonly used in medical definitions. Pyrazines are actually a class of organic compounds that contain a ring made up of two nitrogen atoms and three carbon atoms. They are found in various foods and contribute to their flavors. If you have any questions about organic chemistry or food science, I'd be happy to try to help!

Firefly luciferin is not a medical term, but a biological term used to describe a compound involved in bioluminescence, specifically in fireflies.

Luciferin is a molecule that can produce light when it reacts with oxygen in the presence of an enzyme called luciferase and adenosine triphosphate (ATP), which is a source of energy in cells. In fireflies, this reaction occurs in specialized cells within the lantern organ of the insect, producing the characteristic glowing light.

While not directly related to medical terminology, bioluminescence and its underlying mechanisms have been studied for potential applications in medical research, such as developing sensitive biosensors for detecting various biological molecules or monitoring cellular processes.

Arsenazo III is a chemical compound that is used as a complexometric reagent in analytical chemistry, particularly for the determination of metal ions such as calcium and magnesium. It forms stable, brightly colored chelates with these metals, allowing for their quantitative analysis through spectrophotometry or other techniques. Arsenazo III is also used in some medical tests, such as the arsenazo III calcium test, to measure serum calcium levels.

I apologize, but I am not able to provide a medical definition for "Egtazic Acid" because it is not a term that is recognized in the field of medicine or pharmacology. It is possible that you may have meant "Egтарic Acid," which also does not have a specific medical meaning, or "Ethylene Glycol Tetraacetic Acid (EGTA)," which is a chemical compound used in research and medicine for its ability to bind calcium ions. If you have any other questions, I would be happy to try to help answer them.

Myocardial contraction refers to the rhythmic and forceful shortening of heart muscle cells (myocytes) in the myocardium, which is the muscular wall of the heart. This process is initiated by electrical signals generated by the sinoatrial node, causing a wave of depolarization that spreads throughout the heart.

During myocardial contraction, calcium ions flow into the myocytes, triggering the interaction between actin and myosin filaments, which are the contractile proteins in the muscle cells. This interaction causes the myofilaments to slide past each other, resulting in the shortening of the sarcomeres (the functional units of muscle contraction) and ultimately leading to the contraction of the heart muscle.

Myocardial contraction is essential for pumping blood throughout the body and maintaining adequate circulation to vital organs. Any impairment in myocardial contractility can lead to various cardiac disorders, such as heart failure, cardiomyopathy, and arrhythmias.

Ryanodine is not a medical condition or term, but it is a chemical compound that interacts with ryanodine receptors (RyRs), which are calcium release channels found in the sarcoplasmic reticulum of muscle cells. Ryanodine receptors play a crucial role in excitation-contraction coupling, which is the process by which electrical signals trigger muscle contractions.

Ryanodine itself is a plant alkaloid that was initially isolated from the South American shrub Ryania speciosa. It can bind to and inhibit ryanodine receptors, altering calcium signaling in muscle cells. This ability of ryanodine to modulate calcium release has made it a valuable tool in researching excitation-contraction coupling and related processes.

In some cases, the term "ryanodine" may be used in a medical context to refer to the effects of ryanodine or ryanodine receptor modulation on muscle function, particularly in relation to diseases associated with calcium handling abnormalities. However, it is not a medical condition per se.

Chemical characterization of aequorin indicates the protein is somewhat resilient to harsh treatments. Aequorin is heat ... Shimomura O, Inouye S, Musicki B, Kishi Y (1990). "Recombinant aequorin and recombinant semi-synthetic aequorins. Cellular Ca2+ ... making aequorin suitable as a Ca2+ reporter in plants, fungi, and mammalian cells. Aequorin has a number of advantages over ... not aequorin, although both originally derive from the same animal. Apoaequorin, the protein portion of aequorin, is an ...
Aequorin luminescence imaging. Transgenic A. thaliana (L.) Heynh Col-0 wild-type expressing the APOAEQUORIN gene under control ... Aequorin luminescence imaging was performed using a highly sensitive CCD camera iKon-XL (Oxford Instruments plc, Tubney Woods, ... thaliana plants expressing APOAEQUORIN treated with coelenterazine for AEQUORIN reconstitution, in response to diethyl ether ... confirming that the signal in AEQUORIN plants came from increased [Ca2+]cyt. ...
... aequorin, a substance that emits light when it combines with calcium ion (Ca++). Small amounts of aequorin were microinjected ... aequorin, a substance that emits light when it combines with calcium ion (Ca++). Small amounts of aequorin were microinjected ... aequorin, a substance that emits light when it combines with calcium ion (Ca++). Small amounts of aequorin were microinjected ... aequorin, a substance that emits light when it combines with calcium ion (Ca++). Small amounts of aequorin were microinjected ...
... insulin secretion from INS-1 cells stably expressing the Ca2+-sensitive photoprotein aequorin in the appropriate ... quired for aequorin activation (31). The highest expressers of ae- quorin were termed EK-3 for the mitochondrial aequorin cell ... m as meaured by aequorin, and [Ca21]c as measured by both fura-2 and ae- quorin in INS-1 EK-3 and C-29 cell lines. (A) [Ca21]m ... in Aequorin-expressing INS-1 Cells. Eleanor D. Kennedy,* Rosario Rizzuto,‡ Jean-Marc Theler,* William-F. Pralong,* Carlo ...
26] Isolation and expression of a cDNA coding for aequorin, the Ca2+-activated photoprotein from Aequorea victoria. Methods in ... A short story of aequorin. The Biological Bulletin 189:1-5, https://doi.org/​10.2307/1542194. ...
PDB Description: Crystal structure of i-aequorin. PDB Compounds: (B:) Aequorin 2. SCOP Domain Sequences for d1uhib1:. Sequence ... Species Jellyfish (Aequorea aequorea), aequorin [TaxId:168712] [47513] (5 PDB entries). *. Domain d1uhib1: 1uhi B:3-189 [119678 ... d1uhib1 a.39.1.5 (B:3-189) Calcium-regulated photoprotein {Jellyfish (Aequorea aequorea), aequorin [TaxId: 168712]} ...
Aequorin was first. discovered in the jellyfish. Aequorea victoria. Image courtesy of Typoform /. the Royal Swedish Academy of ... There have been a number of experiments investigating aequorin, a protein found in certain jellyfish, which produces blue light ...
George, C., Kendall, J., Campbell, A., Evans, W., & George, C. (1998). Connexin-Aequorin Chimerae Report Cytoplasmic Calcium ... Assembly of Chimeric Connexin-Aequorin Proteins into Functional Gap Junction Channels. Journal of Biological Chemistry, 273(3) ... Reporting the calcium environment in trafficking pathways leading to gap junction biogenesis using connexion-aequorin chimera. ... Reporting the Calcium Environment in Trafficking Pathways Leading to Gap Junction Biogenesis Using Connexin-Aequorin Chimerae. ...
The remaining aequorin was discharged for 5 min using a mixture containing 2 M CaCl2, 20% ethanol (v/v), and 0.01% Triton X-100 ... by aequorin luminometry. Col-0 seeds were obtained from the European Arabidopsis Stock Centre (arabidopsis.info). For all ... elevations, 0.01-30 mM AA was added to excised roots of intact A. thaliana plants constitutively expressing aequorin (Fig. 1). ... Nevertheless, iron chelators were effective in aequorin luminometry, suggesting that catalytically active bio-available iron ...
... e instaurazione del Regne di Dio nel pensiero dei text? shop História aequorin automá. 101-104, 165-168, 198-202 ...
"Surface properties of Jellyfish: Langmuir monolayer and Langmuir-Blodgett film studies of recombinant aequorin". 15. Wang C ... "Infrared Reflection-Absorption Spectroscopy (IRRAS) and Polarization Modulated-IRRAS (PM-IRRAS) Study of the Aequorin Langmuir ...
Different stress-induced calcium signatures are reported by aequorin-mediated calcium measurements in living cells of ...
Aequorin 08711794000600長山礼三: 第28回日本臨床血液学会総会抄録集. 281 (1986) / 【Ca^(++)】動員 / Aequorin. ... Publications] Nagayama,R.et al.: Platelet ionized calcium mobilization (Aequorin method) in patients with primary platelet ... 2 or arachidonate-induction using aequorin loading method. In presence of L mM Ca^,++,, patient (P) platelets showed
Shimomura, O., Johnson, F. H. & Saiga, Y. Extraction, purification and properties of aequorin, a bioluminescent protein from ...
Shimomura first isolated GFP, along with a protein called aequorin, in the crystal jellyfish, Aequorea victoria, which is found ...
Prevagen (aequorin) Jellyfish Fight Aging. Quincy Bioscience. 4.5 Stars. Diesel Energy Stix. Diesel. 4.5 Stars. Focus Formula ... Prevagen (aequorin) Jellyfish Fight Aging I am a Pastor from N. Carolina. Prevagen has been helping me greatly. I am sleeping ...
Its role is to transduce the blue chemiluminescence of the protein aequorin into green fluorescent light by energy transfer. ... Fluoresces in vivo upon receiving energy from the Ca(2+)-activated photoprotein aequorin. ...
to test its effect in the induction of Ca2+ flux in rice roots using aequorin luminescence imaging ...
A toolset of aequorin expression vectors for in planta studies of subcellular calcium concentrations in Arabidopsis thaliana. ... cellular response by temporal and spatial changes in cellular calcium concentration and the calcium-sensitive protein aequorin ...
A high-throughput assay for connexin 43 (Cx43, GJA1) gap junctions using codon-optimized aequorin. Assay Drug Dev Technol. 2013 ...
Figure.2(a.)Aequorin-GFP sequence after purify gel image。Left:(1)100b.p. marker,(2)Aequorin-GFP。(b.)After TA cloning ... And took the successful purify Aequorin-GFP to run the TA cloning, let Aequorin-GFP could ligate to Pgem-T-easy plasmid. After ... The Aequorin-GFP size was about 2000bp;Fig.2-a show that template was placed at 2000 bp,so it confirm that suecssfully purify ... Because of Aequorin-GFP didnt know the purify and concentration;Through PCR, we run the purify step to increasing the purify. ...
Aequorin, from the jellyfish Aequorea victoria, produces a blue glow in the presence of Ca2+ ions (by a chemical reaction). It ... The success with aequorin spurred further investigation of A. victoria and led to the discovery of Green Fluorescent Protein ( ...
In the jellyfish, GFP interacts with another protein, called aequorin, which emits blue light when added with calcium. ... which they called aequorin. When they purified aequorin, they also discovered traces of another protein, which showed green ... "The Discovery of Aequorin and Green Fluorescent Protein." Journal of Microscopy 217 (2005): 3-15. "The Nobel Prize in Chemistry ... Shimomura focused on aequorin, purified the protein, crystallized it, and elucidated its underlying structure. He also studied ...
... and aequorin), radiolabels (e.g., 3H, 125I, 35S, 14C, or 32P), enzymes (e.g., galactosidases, glucorinidases, phosphatases (e.g ... Aequorin (Photoprotein); Alexa Fluor 350™; Alexa Fluor 430™; Alexa Fluor 488™; Alexa Fluor 532™; Alexa Fluor 546™; Alexa Fluor ...
Some of the first calcium sensors used the calcium-sensitivity of aequorin and led to a number of discoveries (Ref 46) . The ... In the jellyfish, in the presence of Calcium ions, Aequorin can to turn into an excited form that relaxes with the emission of ... In 1962, while trying to isolate the bioluminescent protein Aequorin from the jellyfish Aequorea victoria, the Japanese ... 5. O. Shimomura, « The discovery of aequorin and green fluorescent protein », Journal of Microscopy, vol. 217, pp. 3-15, jan ...
K. Glynou, P. C. Ioannou, and T. K. Christopoulos, "One-step purification and refolding of recombinant photoprotein aequorin by ...
EC50s of 3.6 nM and 36 nM for GPR40 in A9 cells (GPR40 IP3 assay) and CHO cells (GPR40 aequorin assay), respectively. ... EC50s of 3.6 nM and 36 nM for GPR40 in A9 cells (GPR40 IP3 assay) and CHO cells (GPR40 aequorin assay), respectively. ... EC50s of 3.6 nM and 36 nM for GPR40 in A9 cells (GPR40 IP3 assay) and CHO cells (GPR40 aequorin assay), respectively. ...
Aequorin-expressing yeast emits light under electric control  Vilanova, Cristina; Hueso,Ángeles; Palanca, Carles; Marco, ... aequorin, expressed in a transgenic yeast strain. Yeast cultures were electrically stimulated ... ...

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