Experimental Design And Characterization Of Nanoemulsion Based Topical Herbal Gel Developed For Site-Specific Activity Of Glycyrrhiza Glabra Extract: In Vitro And Ex- Vivo Studies

2019 ◽  
Vol 12 (2) ◽  
pp. 408-418 ◽  
Author(s):  
Anil Tatiya ◽  
Snehal Bhavsar ◽  
Hitendra Mahajan ◽  
Sanjay Surana
Keyword(s):  
Experimental Design ◽  
Specific Activity ◽  
Ex Vivo ◽  
Glycyrrhiza Glabra ◽  
Site Specific

Assays for Phospholipid-Dependent Formation of Thrombin and Xa: A Potential Method for Quantifying Lupus Anticoagulant Activity

1991 ◽  
Vol 66 (04) ◽  
pp. 453-458 ◽  
Author(s):  
John T Brandt
Keyword(s):  
Specific Activity ◽  
Anticoagulant Activity ◽  
Factor Xa ◽  
Clinical Importance ◽  
Potential Method ◽  
Quantitative Expression ◽  
Increased Risk ◽  
Apparent Association

SummaryLupus anticoagulants (LAs) are antibodies which interfere with phospholipid-dependent procoagulant reactions. Their clinical importance is due to their apparent association with an increased risk of thrombo-embolic disease. To date there have been few assays for quantifying the specific activity of these antibodies in vitro and this has hampered attempts to purify and characterize these antibodies. Methods for determining phospholipid-dependent generation of thrombin and factor Xa are described. Isolated IgG fractions from 7 of 9 patients with LAs were found to reproducibly inhibit enzyme generation in these assay systems, permitting quantitative expression of inhibitor activity. Different patterns of inhibitory activity, based on the relative inhibition of thrombin and factor Xa generation, were found, further substantiating the known heterogeneity of these antibodies. These systems may prove helpful in further purification and characterization of LAs.

scholarly journals In-Vitro, Ex-Vivo Characterization of Furosemide Bounded Pharmacosomes for Improvement of Solubility and Permeability

2014 ◽  
Vol 2 (5) ◽  
pp. 67-76
Author(s):  
Vivekanand K.Chatap ◽  
Prashant L. Patil ◽  
Savita D. Patil
Keyword(s):  
Ex Vivo

scholarly journals Formulation and characterization of chlorhexidine HCl nanoemulsion as a promising antibacterial root canal irrigant: in-vitro and ex-vivo studies

2019 ◽  
Vol Volume 14 ◽  
pp. 4697-4708 ◽  
Author(s):  
Rehab Abdelmonem ◽  
Mona K. Younis ◽  
Doaa H Hassan ◽  
Mohamed Abd El-Gawad El-Sayed Ahmed ◽  
Ehab Hassanien ◽  
...  
Keyword(s):  
Root Canal ◽  
Ex Vivo ◽  
Root Canal Irrigant

scholarly journals Purification and Characterization of the R64 Shufflon-Specific Recombinase

2000 ◽  
Vol 182 (10) ◽  
pp. 2787-2792 ◽  
Author(s):  
Atsuko Gyohda ◽  
Teruya Komano
Keyword(s):  
Electrophoretic Analysis ◽  
Recombination Reaction ◽  
Site Specific ◽  
Dna Inversion ◽  
Repeat Sequences ◽  
In Vitro Recombination ◽  
Recombinase Gene ◽  
A Site

ABSTRACT The shufflon, a multiple DNA inversion system in plasmid R64, consists of four invertible DNA segments which are separated and flanked by seven 19-bp repeat sequences. The product of a site-specific recombinase gene, rci, promotes site-specific recombination between any two of the inverted 19-bp repeat sequences of the shufflon. To analyze the molecular mechanism of this recombination reaction, Rci protein was overproduced and purified. The purified Rci protein promoted the in vitro recombination reaction between the inverted 19-bp repeats of supercoiled DNA of a plasmid carrying segment A of the R64 shufflon. The recombination reaction was enhanced by the bacterial host factor HU. Gel electrophoretic analysis indicated that the Rci protein specifically binds to the DNA segments carrying the 19-bp sequences. The binding affinity of the Rci protein to the four shufflon segments as well as four synthetic 19-bp sequences differed greatly: among the four 19-bp repeat sequences, the repeat-a and -d sequences displayed higher affinity to Rci protein. These results suggest that the differences in the affinity of Rci protein for the 19-bp repeat sequences determine the inversion frequencies of the four segments.

Development of an in vitro model of calcified cerebral emboli in acute ischemic stroke for mechanical thrombectomy evaluation

2020 ◽  
Vol 12 (10) ◽  
pp. 1002-1007
Author(s):  
Sarah Johnson ◽  
Ray McCarthy ◽  
Brian Fahy ◽  
Oana Madalina Mereuta ◽  
Seán Fitzgerald ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
In Vitro Model ◽  
Mechanical Thrombectomy ◽  
Ex Vivo ◽  
Guide Catheter ◽  
Vitro Model ◽  
Calcified Tissues

​BackgroundCalcified cerebral emboli (CCEs) are a rare cause of acute ischemic stroke (AIS) and are frequently associated with poor outcomes. The presence of dense calcified material enables reliable identification of CCEs using non-contrast CT. However, recanalization rates with the available mechanical thrombectomy (MT) devices remain low.ObjectiveTo recreate a large vessel occlusion involving a CCE using an in vitro silicone model of the intracranial vessels and to demonstrate the feasability of this model to test different endovascular strategies to recanalize an occlusion of the M1 segment of the middle cerebral artery (MCA).​MethodsAn in vitro model was developed to evaluate different endovascular treatment approaches using contemporary devices in the M1 segment of the MCA. The in vitro model consisted of a CCE analog placed in a silicone neurovascular model. Development of an appropriate CCE analog was based on characterization of human calcified tissues that represent likely sources of CCEs. Feasibility of the model was demonstrated in a small number of MT devices using four common procedural techniques.​ResultsCCE analogs were developed with similar mechanical behavior to that of ex vivo calcified material. The in vitro model was evaluated with various MT techniques and devices to show feasibility of the model. In this limited evaluation, the most successful retrieval approach was performed with a stent retriever combined with local aspiration through a distal access catheter, and importantly, with flow arrest and dual aspiration using a balloon guide catheter.​ConclusionCharacterization of calcified tissues, which are likely sources of CCEs, has shown that CCEs are considerably stiffer than thrombus. This highlights the need for a different in vitro AIS model for CCEs than those used for thromboemboli. Consequentially, an in vitro AIS model representative of a CCE occlusion in the M1 segment of the MCA has been developed.

Phosphorylation of eNOS initiates excessive NO production in early phases of portal hypertension

2002 ◽  
Vol 282 (6) ◽  
pp. H2084-H2090 ◽  
Author(s):  
Yasuko Iwakiri ◽  
Ming-Hung Tsai ◽  
Timothy J. McCabe ◽  
Jean-Philippe Gratton ◽  
David Fulton ◽  
...  
Keyword(s):  
Portal Hypertension ◽  
Specific Activity ◽  
Ex Vivo ◽  
Active Form ◽  
Initial Increase ◽  
No Production ◽  
Portal Vein Ligation ◽  
Sprague Dawley ◽  
Perfusion Studies

Akt, also known as protein kinase B, is a serine/threonine kinase. Akt becomes active when phosphorylated by the activation of receptor tyrosine kinases, G protein-coupled receptors, and mechanical forces such as shear stress. Studies in vitro have shown that Akt can directly phosphorylate endothelial nitric oxide (NO) synthase (eNOS) and activate the enzyme, leading to NO production. The aim of this study was to test the hypothesis that the phosphorylation of eNOS plays a role in the enhanced NO production observed in early portal hypertension. Male Sprague-Dawley rats were subjected to either sham or portal vein ligation (PVL), and mesenteric arterial beds were used for ex vivo perfusion studies. Mesenteric arterial beds from PVL rats had an approximately 60–70% decrease in response to methoxamine (an α1-agonist and vasoconstrictor) compared with the sham group ( P < 0.01). When N G-monomethyl-l-arginine (a NOS inhibitor) was added to the perfusion, the difference in perfusion pressure between the two groups was abolished, suggesting that enhanced NO production in the PVL group blunted the response to the vasoconstrictor. The reduced responsiveness in PVL was not due to changes in eNOS expression but was due to an increase in enzyme-specific activity, suggesting posttranslational modification of eNOS. The phosphorylation of eNOS at Ser1176 was significantly increased by twofold ( P < 0.05) in the PVL group. Furthermore, PVL significantly increased Akt phosphorylation (an active form of Akt) by threefold ( P< 0.05). When vessels were treated with wortmannin (10 nM) to block the phosphatidylinositol-3-OH-kinase/Akt pathway, NO-induced vasodilatation was significantly reduced. These results suggest that the phosphorylation of eNOS by Akt activates the enzyme and may be the first step leading to an initial increase in NO production in portal hypertension.

scholarly journals Complex formation between urokinase and plasma protein C inhibitor in vitro and in vivo

Blood ◽  
1989 ◽  
Vol 74 (2) ◽  
pp. 722-728 ◽  
Author(s):  
M Geiger ◽  
K Huber ◽  
J Wojta ◽  
L Stingl ◽  
F Espana ◽  
...  
Keyword(s):  
Complex Formation ◽  
Protein C ◽  
Specific Activity ◽  
Ex Vivo ◽  
Plasminogen Activator Inhibitor ◽  
Enzyme Linked Immunosorbent Assay ◽  
Plasma Samples ◽  
Protein C Inhibitor

Abstract Protein C inhibitor (PCI) and plasminogen activator inhibitor 3 (PAI-3; urinary urokinase inhibitor) are immunologically identical. The role of PCI for urokinase (uPA) inhibition in vivo was investigated. We therefore developed an enzyme-linked immunosorbent assay (ELISA) specific for uPA-PCI complexes: Rabbit anti-PCI IgG was immobilized on a microtiter plate and following incubation with uPA-PCI complex- containing samples, bound uPA-PCI complexes were quantified with a horseradish-peroxidase-linked monoclonal antibody (MoAb) to uPA. Using this assay, time, dose, and heparin-dependent complexes were detected when uPA was incubated with normal plasma or purified urinary PCI, whereas no complexes were measurable using PCI-immunodepleted plasma. Plasma samples (containing 20 mmol/L benzamidine to prevent complex formation ex vivo) from patients undergoing systemic urokinase therapy (1 x 10(6) IU/60 min intravenously [IV]) after myocardial infarction were also studied. uPA present in these plasma samples (up to 1,200 ng/mL) had only 43% to 70% of the specific activity of purified 2-chain uPA, suggesting that a major portion of uPA is complexed to inhibitors. In these plasma samples uPA-PCI complexes were present in a concentration corresponding to 21% to 25% of inactive uPA antigen. These data suggest that at high uPA concentrations, such as during uPA therapy, plasma PCI might contribute significantly to uPA inhibition in vivo.

scholarly journals Development and Characterization of Potential Ocular Mucoadhesive Nano Lipid Carriers Using Full Factorial Design

Pharmaceutics ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 682
Author(s):  
Eszter L. Kiss ◽  
Szilvia Berkó ◽  
Attila Gácsi ◽  
Anita Kovács ◽  
Gábor Katona ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Harmful Effect ◽  
Cell Junctions ◽  
Toxicity Tests ◽  
Eye Drops ◽  
Corneal Toxicity ◽  
Penetration Tests ◽  
Full Factorial

Generally, topically applied eye drops have low bioavailability due to short residence time and low penetration of the drug. The aim of the present study was to incorporate dexamethasone (DXM) into nano lipid carriers (NLC), which contain mucoadhesive polymer, in order to increase the bioavailability of the drug. A 23 factorial experimental design was applied, in which the three factors were the polymer, the DXM, and the emulsifier concentrations. The samples were analyzed for particle size, zeta potential, polydispersity index, and Span value. The significant factors were identified. The biocompatibility of the formulations was evaluated with human corneal toxicity tests and immunoassay analysis. The possible increase in bioavailability was analyzed by means of mucoadhesivity, in vitro drug diffusion, and different penetration tests, such as in vitro cornea PAMPA model, human corneal cell penetration, and ex vivo porcine corneal penetration using Raman mapping. The results indicated that DXM can be incorporated in stable mucoadhesive NLC systems, which are non-toxic and do not have any harmful effect on cell junctions. Mucoadhesive NLCs can create a depot on the surface of the cornea, which can predict improved bioavailability.

Sign in / Sign up

Export Citation Format

Share Document