scholarly journals Tyrosinases from crustaceans form hexamers

2003 ◽  
Vol 371 (2) ◽  
pp. 515-523 ◽  
Author(s):  
Elmar JAENICKE ◽  
Heinz DECKER
Keyword(s):  
Oxygen Carrier ◽  
Spiny Lobster ◽  
Physicochemical Characterization ◽  
Primary Immune Response ◽  
Freshwater Crayfish ◽  
Astacus Leptodactylus ◽  
Purification Protocol ◽  
Palinurus Elephas

Tyrosinases, which are widely distributed among animals, plants and fungi, are involved in many biologically essential functions, including pigmentation, sclerotization, primary immune response and host defence. In the present study, we present a structural and physicochemical characterization of two new tyrosinases from the crustaceans Palinurus elephas (European spiny lobster) and Astacus leptodactylus (freshwater crayfish). In vivo, the purified crustacean tyrosinases occur as hexamers composed of one subunit type with a molecular mass of approx. 71kDa. The tyrosinase hexamers appear to be similar to the haemocyanins, based on electron microscopy. Thus a careful purification protocol was developed to discriminate clearly between tyrosinases and the closely related haemocyanins. The physicochemical properties of haemocyanins and tyrosinases are different with respect to electronegativity and hydrophobicity. The hexameric nature of arthropod tyrosinases suggests that these proteins were the ideal predecessors from which to develop the oxygen-carrier protein haemocyanin, with its allosteric and co-operative properties, later on.

Ultrastructural and functional characterization of circulating hemocytes from the freshwater crayfish Astacus leptodactylus: Cell types and their role after in vivo artificial non-self challenge

Micron ◽  
2007 ◽  
Vol 38 (1) ◽  
pp. 49-57 ◽  
Author(s):  
Piero Giulio Giulianini ◽  
Manuel Bierti ◽  
Simonetta Lorenzon ◽  
Silvia Battistella ◽  
Enrico Antonio Ferrero
Keyword(s):  
Functional Characterization ◽  
Cell Types ◽  
Freshwater Crayfish ◽  
Astacus Leptodactylus

scholarly journals Anti-Inflammatory and Physicochemical Characterization of the Croton rhamnifolioides Essential Oil Inclusion Complex in β-Cyclodextrin

Biology ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 114
Author(s):  
Anita Oliveira Brito Pereira Bezerra Martins ◽  
Almir Gonçalves Wanderley ◽  
Isabel Sousa Alcântara ◽  
Lindaiane Bezerra Rodrigues ◽  
Francisco Rafael Alves Santana Cesário ◽  
...  
Keyword(s):  
Essential Oil ◽  
Vascular Permeability ◽  
Inflammatory Diseases ◽  
Physicochemical Characterization ◽  
Major Constituent ◽  
Paw Edema ◽  
Popular Medicine ◽  
Anti Inflammatory

Croton rhamnifolioides is used in popular medicine for the treatment of inflammatory diseases. The objective of this study was to characterize and evaluate the anti-inflammatory effect of C. rhamnifolioides essential oil complexed in β-cyclodextrin (COEFC). The physicochemical characterization of the complexes was performed using different physical methods. The anti-inflammatory activity was evaluated in vivo by ear edema, paw edema, cotton pellet-induced granuloma, and vascular permeability by Evans blue extravasation. The mechanism of action was validated by molecular docking of the major constituent into the cyclooxygenase-2 (COX-2 enzyme). All doses of the COEFC reduced acute paw edema induced by carrageenan and dextran, as well as vascular permeability. Our results suggest the lowest effective dose of all samples inhibited the response induced by histamine or arachidonic acid as well as the granuloma formation. The complexation process showed that the pharmacological effects were maintained, however, showing similar results using much lower doses. The results demonstrated an involvement of the inhibition of pathways dependent on eicosanoids and histamine. Complexation of β-cyclodextrin/Essential oil (β-CD/EO) may present an important tool in the study of new compounds for the development of anti-inflammatory drugs.

DELIVERY OF STIMULI-SENSITIVE NANOPARTICLES FOR VISUALIZATION OF REACTIVE OXYGEN SPECIES IN LIVER DISEASES

2021 ◽  
Vol 1 (19) ◽  
pp. 67-69
Author(s):  
P.I. Vetosheva ◽  
A.G. Shokhina ◽  
D.M. Melnik ◽  
V.V. Belousov ◽  
T.S. Zatsepin
Keyword(s):  
Reactive Oxygen Species ◽  
Physicochemical Characterization ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Leuco Form ◽  
Effective Visualization ◽  
Stimuli Sensitive

We developed lipid nanoparticles for effective visualization of reactive oxygen species (ROS) in damaged hepatocytes. These nanoparticles contain ROS - sensor: 1) HyPer – plasmid DNA encoded the same protein that is sensitive to the hydrogen peroxide or 2) hydrocyanine (leuco-form of cyanine) 5). The physicochemical characterization of the obtained particles was carried out, as well as their efficacy in vitro and in vivo was evaluated.

scholarly journals Formulation Strategies, Characterization, and In Vitro Evaluation of Lecithin-Based Nanoparticles for siRNA Delivery

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Sebastián Ezequiel Pérez ◽  
Yamila Gándola ◽  
Adriana Mónica Carlucci ◽  
Lorena González ◽  
Daniel Turyn ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Sirna Delivery ◽  
Physicochemical Characterization ◽  
Human Breast ◽  
Efficient Delivery ◽  
Interfering Rna ◽  
Mcf 7

The aim of the present work was to take advantage of lecithin’s biocompatibility along with its physicochemical properties for the preparation of lecithin-based nanocarriers for small interfering RNA (siRNA) delivery. Water lecithin dispersions were prepared in different conditions, loaded with siRNA at different N/P ratios, and evaluated for loading capacity. The most appropriate ones were then assayed for cytotoxicity and characterized in terms of particle size distribution, zeta potential, and morphology. Results demonstrated that formulations prepared at pH 5.0 and 7.0 were able to load siRNA at broad N/P ratios, and cellular uptake assays showed an efficient delivery of oligos in MCF-7 human breast cancer cells; fluorescent-labeled dsRNA mainly located next to its target, near the nucleus of the cells. No signs of toxicity were observed for broad compositions of lecithin. The physicochemical characterization of the siRNA-loaded dispersions exhibited particles of nanometric sizes and pH-dependant shapes, which make them suitable for ex vivo and in vivo further evaluation.

scholarly journals Morphological and Physicochemical Characterization of Agglomerates of Titanium Dioxide Nanoparticles in Cell Culture Media

2016 ◽  
Vol 2016 ◽  
pp. 1-19 ◽  
Author(s):  
Verónica Freyre-Fonseca ◽  
Darío I. Téllez-Medina ◽  
Estefany I. Medina-Reyes ◽  
Maribel Cornejo-Mazón ◽  
Edgar O. López-Villegas ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Culture Media ◽  
Titanium Dioxide Nanoparticles ◽  
Physicochemical Characterization ◽  
Cell Culture Media ◽  
Size Stability ◽  
Maximum Stability

Titanium dioxide nanoparticles (TiO2NP) are possible carcinogenic materials (2B-IARC) and their toxicity depends on shape, size, and electrical charge of primary NP and on the system formed by NP media. The aim of this work was to characterize agglomerates of three TiO2NP by evaluating their morphometry, stability, and zeta potential (ζ) in liquid media and their changes with time. Sizes of agglomerates by dynamic light scattering (DLS) resulted to be 10–50 times larger than those obtained by digital image analysis (DIA) given the charged zone around particles. Fractal dimension (FD) was highest for agglomerates of spheres and belts in F12K, and in E171 in FBS media. E171 and belts increased FD with time. At time zero, using water as dispersant FD was larger for agglomerates of spheres than for of E171. Belts suspended in water had the smallest values of circularity (Ci) which was approximately unchanged with time. All dispersions hadζvalues around −30 mV at physiological pH (7.4) and dispersions of NP in water and FBS showed maximum stability (Turbiscan Lab analysis). Results help in understanding the complex NP geometry-size-stability relationships when performingin vivoandin vitroenvironmental-toxicity works and help in supporting decisions on the usage of TiO2NP.

scholarly journals Physicochemical and Tissue Response of PLA Nanofiber Scaffolds Sterilized by Different Techniques

2018 ◽  
pp. 169-180
Author(s):  
Isarai Mendieta-Barrañon DDS ◽  
Osmar A. Chanes-Cuevas DDS, MSc ◽  
Marco A. Álvarez-Pérez PhD ◽  
Patricia González-Alva DDS, PhD ◽  
Luis A. Medina PhD ◽  
...  
Keyword(s):  
Tissue Regeneration ◽  
Physicochemical Characterization ◽  
Biochemical Properties ◽  
Tissue Reaction ◽  
Tissue Response ◽  
Poly Lactic Acid ◽  
Response Analysis ◽  
Sterile Product

In recent years, tissue engineering has evolved considerably, due to the problems in the biomedical area concerning tissue regeneration therapies. Currently, work has been focused on the synthesis and physicochemical characterization of poly lactic acid scaffolds, a synthetic polyester that has been extensively study for its excellent biocompatibility and biodegradability. Moreover, sterilization strategies of scaffold are a crucial step for its application in tissue regeneration, however, the sterilization process have to maintain the structural and biochemical properties of the scaffold. Therefore, it is very important to carry out studies on the sterilization methods of the sample’s material, since translational medicine is intended for in vivo applications. The aim of the present study was designed to analyze the effects of different sterilization techniques, i.e. ethylene oxide (ETO), gamma radiation (GR) and hydrogen peroxide-based plasma (H2O2) in biodegradable PLA scaffolds, and to determine the best sterilization technique to render a sterile product with minimal degradation and deformation, and good tissue response. Analysis of surface morphology showed that ETO and GR modified the PLA scaffolds without any change in its chemical composition. Moreover, the histological response showed that the scaffolds are biocompatible and those sterilized by GR showed a more severe inflammatory response, accompanied with the presence of giant foreign body cells. In conclusion, the results show that among sterilization techniques used in the preset study, the best results were observed with H2O2 sterilization, since it did not significantly modify the surface structure of the PLA fibers and their in vivo response did not cause an unfavorable tissue reaction.

Physicochemical characterization of cross-linked human serum albumin dimer and its synthetic heme hybrid as an oxygen carrier

2004 ◽  
Vol 1675 (1-3) ◽  
pp. 21-31 ◽  
Author(s):  
Teruyuki Komatsu ◽  
Yukiko Oguro ◽  
Yuji Teramura ◽  
Shinji Takeoka ◽  
Junpei Okai ◽  
...  
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Oxygen Carrier ◽  
Physicochemical Characterization

Ionotropic GABA Receptor From Lobster Olfactory Projection Neurons

1997 ◽  
Vol 77 (5) ◽  
pp. 2235-2251 ◽  
Author(s):  
A. B. Zhainazarov ◽  
M. Wachowiak ◽  
A. Boettcher ◽  
S. Elenes ◽  
B. W. Ache
Keyword(s):  
Gaba Receptors ◽  
Gaba Receptor ◽  
Spiny Lobster ◽  
Equilibrium Potential ◽  
Projection Neurons ◽  
Patch Clamp Recording ◽  
Pharmacological Characterization ◽  
Chloride Currents

Zhainazarov, A. B., M. Wachowiak, A. Boettcher, S. Elenes, and B. W. Ache. Ionotropic GABA receptor from lobster olfactory projection neurons. J. Neurophysiol. 77: 2235–2251, 1997. This study reports an ionotropic GABA (γ-aminobutyric acid) receptor in projection neurons acutely dissociated from the olfactory lobe of the brain of the spiny lobster and analyzed by whole cell and cell-free patch-clamp recording. GABA evokes a macroscopic current in the cells that is linear from −100 to +100 mV, reverses at the imposed chloride equilibrium potential, has a permeability sequence of Cl− > acetate > bicarbonate > phosphate > propionate and SCN− > Br− > I− > Cl− > F−, and is reversibly blocked by the Cl channel blocker picrotoxin but not tert-butylbicyclophosphorothionate (TBPS). The current is bicuculline insensitive and activated by muscimol, isoguvacine, cis-4-aminocrotonic acid (CACA), and trans-aminocrotonic acid (TACA), as well as by the GABAC-receptor antagonists 4,5,6,7-tetrahydroisoxazolo [5,4,-c]pyridin-3-ol (THIP), 3-amino-1-propanesulfonic acid(3-APS), and imidazole-4-acetic acid (I-4AA), but not theGABAB-receptor agonists baclofen and 3-aminopropylphosphonic acid (3-APA). Agonist potency for the receptor is TACA > muscimol > GABA > I-4AA > isoguvacine > 3-APS > CACA > THIP. Unitary chloride currents in cell-free, outside-out patches from the cells share enough of these pharmacological properties to indicate that the channel underlies the macroscopic current. The receptor mediates an inhibitory current in the cells in vivo. The receptor is similar, if not identical, to one from neurons cultured from the thoracic ganglia of the clawed lobster. The more extensive pharmacological characterization of the receptor reported here indicates that this lobster CNS receptor is pharmacologically distinct from previously characterized ionotropic GABA receptors.

scholarly journals Physicochemical characterization and evaluation of in vitro and in vivo toxicity of goldenberry extract nanoemulsion

2019 ◽  
Vol 49 (8) ◽  
Author(s):  
Suelen Santos da Silva ◽  
Maiara Taís Bazana ◽  
Cassandra de Deus ◽  
Marina Lopes Machado ◽  
Larissa Marafiga Cordeiro ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Droplet Diameter ◽  
Physicochemical Characterization ◽  
High Energy ◽  
In Vitro Assays ◽  
Oil In Water ◽  
The Mean

ABSTRACT: Oil-in-water (O/W) nanoemulsion containing goldenberry extract was elaborated using a high-energy ultrasonic bath method. Physicochemical characterization of the formulation was carried out by determining pH, mean droplet diameter, polydispersity index (PDI) and zeta potential. Nanoemulsion toxicity was assessed using in vitro assays with tumor and non-tumor cell lines, and in vivo using Caenorhabditis elegans. The pH of the nanoemulsion was 3.84, the mean droplet diameter was 268 ± 7 nm, PDI 0.113 and zeta potential -13.94 mV. Results of the cytotoxicity assays employing non-tumor cells indicated that the extract associated or not with nanoemulsion maintained cell viability at different concentrations tested. In the assays using tumor lineage, it is observed that the nanoemulsion containing the extract had higher antitumor activity than the free extract. As for the in vivo tests, there was no change in the survival rate of the worms.

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