Interdigitated microelectronic bandage augments hemostasis and clot formation at low applied voltagein vitroandin vivo

Lab on a Chip ◽  
2018 ◽  
Vol 18 (19) ◽  
pp. 2985-2993 ◽  
Author(s):  
Elaissa T. Hardy ◽  
Yannan J. Wang ◽  
Sanathan Iyer ◽  
Robert G. Mannino ◽  
Yumiko Sakurai ◽  
...  
Keyword(s):  
Low Voltage ◽  
Clot Formation ◽  
Microelectronic Device ◽  
Electrical Field

An interdigitated microelectronic device that applies low voltage (<9 V) electrical field augments hemostasisin vitroandin vivo.

Release of epithelium-derived PGE2 from canine trachea after antigen inhalation

1998 ◽  
Vol 274 (2) ◽  
pp. L220-L225 ◽  
Author(s):  
I. McGrogan ◽  
L. J. Janssen ◽  
J. Wattie ◽  
P. M. O’Byrne ◽  
E. E. Daniel
Keyword(s):  
Smooth Muscle ◽  
Electrical Field Stimulation ◽  
Tracheal Smooth Muscle ◽  
Organ Bath ◽  
Field Stimulation ◽  
Electrical Field ◽  
Concentration Response Curve

To investigate the role of prostaglandin (PG) E2 in allergen-induced hyperresponsiveness, dogs inhaled either the allergen Ascaris suum or vehicle (Sham). Twenty-four hours after inhalation, some animals exposed to allergen demonstrated an increased responsiveness to acetylcholine challenge in vivo (Hyp-Resp), whereas others did not (Non-Resp). Strips of tracheal smooth muscle, either epithelium intact or epithelium denuded, were suspended on stimulating electrodes, and a concentration-response curve to carbachol (10−9 to 10−5 M) was generated. Tissues received electrical field stimulation, and organ bath fluid was collected to determine PGE2content. With the epithelium present, all three groups contracted similarly to 10−5 M carbachol, whereas epithelium-denuded tissues from animals that inhaled allergen contracted more than tissues from Sham dogs. In response to electrical field stimulation, Hyp-Resp tissues contracted less than Sham tissues in the presence of epithelium and more than Sham tissues in the absence of epithelium. PGE2release in the muscle bath was greater in Non-Resp tissues than in Sham or Hyp-Resp tissues when the epithelium was present. Removal of the epithelium greatly inhibited PGE2release. We conclude that tracheal smooth muscle is hyperresponsive in vitro after in vivo allergen exposure only when the modulatory effect of the epithelium, largely through PGE2 release, is removed.

Role of factor XIII in fibrin clot formation and effects of genetic polymorphisms

Blood ◽  
2002 ◽  
Vol 100 (3) ◽  
pp. 743-754 ◽  
Author(s):  
Robert A. S. Ariëns ◽  
Thung-Shenq Lai ◽  
John W. Weisel ◽  
Charles S. Greenberg ◽  
Peter J. Grant
Keyword(s):  
Genetic Polymorphisms ◽  
Factor Xiii ◽  
Blood Clot ◽  
Site Directed Mutagenesis ◽  
Clot Formation ◽  
Factor Xiiia ◽  
Clotting Factors ◽  
Functional Features

Abstract Factor XIII and fibrinogen are unusual among clotting factors in that neither is a serine protease. Fibrin is the main protein constituent of the blood clot, which is stabilized by factor XIIIa through an amide or isopeptide bond that ligates adjacent fibrin monomers. Many of the structural and functional features of factor XIII and fibrin(ogen) have been elucidated by protein and gene analysis, site-directed mutagenesis, and x-ray crystallography. However, some of the molecular aspects involved in the complex processes of insoluble fibrin formation in vivo and in vitro remain unresolved. The findings of a relationship between fibrinogen, factor XIII, and cardiovascular or other thrombotic disorders have focused much attention on these 2 proteins. Of particular interest are associations between common variations in the genes of factor XIII and altered risk profiles for thrombosis. Although there is much debate regarding these observations, the implications for our understanding of clot formation and therapeutic intervention may be of major importance. In this review, we have summarized recent findings on the structure and function of factor XIII. This is followed by a review of the effects of genetic polymorphisms on protein structure/function and their relationship to disease.

In vitro and in vivo assessment of oxygenator blood volume for the prediction of clot formation in an ECMO circuit (theory and validation)

Perfusion ◽  
2018 ◽  
Vol 33 (1_suppl) ◽  
pp. 51-56 ◽  
Author(s):  
Nikolai Krivitski ◽  
Gregory Galyanov ◽  
Deborah Cooper ◽  
Mariam M. Said ◽  
Oswaldo Rivera ◽  
...  
Keyword(s):  
Blood Volume ◽  
Meta Analysis ◽  
Clot Formation ◽  
Ecmo Circuit ◽  
Mortality And Morbidity ◽  
Ultrasound Dilution ◽  
Causes Of Mortality ◽  
Clinical Measurements

Introduction: Clotting is one of the major causes of mortality and morbidity during extracorporeal membrane oxygenation (ECMO). A large meta-analysis study suggests that 29% of patients require the oxygenator to be replaced during ECMO. As clots usually form in the oxygenator, the oxygenator blood volume (OXBV) decreases over time. The currently used pressure gradient as a predicator of clot formation is unreliable. Objective: The aim of this study was to develop and validate ultrasound dilution technology in a quantitative assessment of clotting, using measurements of OXBV. Methods: OXBV was measured using the ELSA monitor (Transonic Systems Inc., Ithaca, NY, USA) from the transit time of a saline bolus passing through the oxygenator as recorded by a sensor placed after the oxygenator. The accuracy and reproducibility (coefficient of variation [CV]) of OXBV measurement and its independence from ECMO flow was assessed in vitro in lambs and from a clinical data archive. Results: The in vitro accuracy compared with volumetric measurements of OXBV of 22-134 ml at flows of 300-700 ml/min was −0.8±6.6%. For an OXBV of 355 ml at flows of 1020-7000 ml/min, accuracy was −0.4±1.6%. In 88 animal OXBV measurements, the CV was 1.49±1.12%. For an OXBV of 153 (range 42-387 ml), clinical measurements at flow ranged from 210-5960 ml/min, with a CV of 3.20±2.44 %. Conclusion: Dilution technology has the ability to accurately and reproducibly assess the clotting process in the oxygenator. Larger studies are needed to establish guidelines for the prediction of imminent clotting and may help to avoid unnecessary circuit changes.

scholarly journals Electrochemistry as a surrogate for protein phosphorylation: voltage-controlled assembly of reflectin A1

2020 ◽  
Vol 17 (173) ◽  
pp. 20200774
Author(s):  
Sheng-Ping Liang ◽  
Robert Levenson ◽  
Brandon Malady ◽  
Michael J. Gordon ◽  
Daniel E. Morse ◽  
...  
Keyword(s):  
Low Voltage ◽  
Selective Reduction ◽  
Structure And Function ◽  
Fine Tuning ◽  
Primary Amines ◽  
Environmental Signals ◽  
Instrument Measuring ◽  
And Function

Phosphorylation is among the most widely distributed mechanisms regulating the tunable structure and function of proteins in response to neuronal, hormonal and environmental signals. We demonstrate here that the low-voltage electrochemical reduction of histidine residues in reflectin A1, a protein that mediates the neuronal fine-tuning of colour reflected from skin cells for camouflage and communication in squids, acts as an in vitro surrogate for phosphorylation in vivo , driving the assembly previously shown to regulate its function. Using micro-drop voltammetry and a newly designed electrochemical cell integrated with an instrument measuring dynamic light scattering, we demonstrate selective reduction of the imidazolium side chains of histidine in monomers, oligopeptides and this complex protein in solution. The formal reduction potential of imidazolium proves readily distinguishable from those of hydronium and primary amines, allowing unequivocal confirmation of the direct and energetically selective deprotonation of histidine in the protein. The resulting ‘electro-assembly’ provides a new approach to probe, understand, and control the mechanisms that dynamically tune protein structure and function in normal physiology and disease. With its abilities to serve as a surrogate for phosphorylation and other mechanisms of charge neutralization, and to potentially isolate early intermediates in protein assembly, this method may be useful for analysing never-before-seen early intermediates in the phosphorylation-driven assembly of other proteins in normal physiology and disease.

Development of MDL 28,050, a Small Stable Antithrombin Agent Based on a Functional Domain of the Leech Protein, Hirudin

1990 ◽  
Vol 63 (02) ◽  
pp. 208-214 ◽  
Author(s):  
John L Krstenansky ◽  
Robert J Broersma ◽  
Thomas J Owen ◽  
Marguerite H Payne ◽  
Mark T Yates ◽  
...  
Keyword(s):  
Structural Optimization ◽  
Systematic Study ◽  
Fibrin Clot ◽  
Clot Formation ◽  
Functional Domain ◽  
In Vivo Models ◽  
Agent Based ◽  
Structure Activity

SummaryMDL 28,050 is a decapeptide antithrombin agent that inhibits a-thrombin-induced fibrin clot formation by binding to a non-catalytic site on α-thromhin. It is the result of chemical and structural optimization of a functional domain of the leech anticoagulant, hirudin. In contrast to the contention that the polyanionic nature of this C-terminal functional domain governs its interaction with α-thrombin, systematic study of this region has shown the importance of the lipophilic residues for providing the functionality necessary foi potent binding to a-thrombin. The development of MDL 28,050 and other effective antithrombin agents are outlined through the description of the structure-activity relationships (SAR) for these peptides. These peptides are effective in a variety of in vitro and in vivo models of thrombosis.

scholarly journals Nanoencapsulation Enhances Anticoagulant Activity of Adenosine and Dipeptide IleTrp

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1191
Author(s):  
Trung Dinh Nguyen ◽  
The Ngoc Nguyen ◽  
Trang Thuy Thi Nguyen ◽  
Igor A. Ivanov ◽  
Khoa Cuu Nguyen ◽  
...  
Keyword(s):  
Biological Activity ◽  
Bleeding Time ◽  
Anticoagulant Activity ◽  
The Body ◽  
Clot Formation ◽  
Pluronic P123 ◽  
Transmission Electron ◽  
Clot Formation Time

It is well-known that drugs administered into an organism intravenously or through the gastrointestinal tract are degraded by enzymes of the body, reducing their therapeutic effect. One of the ways to decrease this undesirable process is through the inclusion of drugs in nanomaterials. Earlier strong anticoagulant activity was demonstrated for dipeptide IleTrp (IW) and adenosine (Ado). In this work, the effect of inclusion in nanomaterials on the biological activity of IW and Ado was studied. For this purpose, Ado and IW were incorporated into thermosensitive nanogel composed of pluronic P123-grafted heparin. The prepared nanocarrier was characterized by transmission electron microscopy, dynamic light scattering, and ζ-potential. Biological activity was determined by measuring the bleeding time from mouse tail in vivo and the time of clot formation in vitro. It was found that encapsulation of Ado and IW into nanomaterial significantly increased their effects, resulting in an increase in the bleeding time from mouse tail and clot formation time. Thus, inclusion of low molecular weight anticoagulants Ado and IW into nanomaterials may be considered a way to increase their biological activity.

Airway smooth muscle responsiveness from dogs with airway hyperresponsiveness after O3 inhalation

1988 ◽  
Vol 65 (1) ◽  
pp. 57-64 ◽  
Author(s):  
G. L. Jones ◽  
P. M. O'Byrne ◽  
M. Pashley ◽  
R. Serio ◽  
J. Jury ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Potassium Chloride ◽  
Airway Smooth Muscle ◽  
Airway Hyperresponsiveness ◽  
Electrical Field Stimulation ◽  
Field Stimulation ◽  
Electrical Field ◽  
Trachealis Muscle

Airway hyperresponsiveness occurs after inhalation of O3 in dogs. The purpose of this study was to examine the responsiveness of trachealis smooth muscle in vitro to electrical field stimulation, exogenous acetylcholine, and potassium chloride from dogs with airway hyperresponsiveness after inhaled O3 in vivo and to compare this with the responsiveness of trachealis muscle from control dogs. In addition, excitatory junction potentials were measured with the use of single and double sucrose gap techniques in both groups of dogs to determine whether inhaled O3 affects the release of acetylcholine from parasympathetic nerves in trachealis muscle. Airway hyperresponsiveness developed in all dogs after inhaled O3 (3 ppm for 30 min). The acetylcholine provocative concentration decreased from 4.11 mg/ml before O3 inhalation to 0.66 mg/ml after O3 (P less than 0.0001). The acetylcholine provocative concentration increased slightly after control inhalation of dry room air. Airway smooth muscle showed increased responses to both electrical field stimulation and exogenous acetylcholine but not to potassium chloride in preparations from dogs with airway hyperresponsiveness in vivo. The increased response to electrical field stimulation was not associated with a change in excitatory junctional potentials. These results suggest that a postjunctional alteration in trachealis muscle function occurs after inhaled O3 in dogs, which may account for airway hyperresponsiveness after O3 in vivo.

Mechanism underlying ozone-induced in vitro hyperresponsiveness in canine bronchi

1991 ◽  
Vol 261 (2) ◽  
pp. L55-L62
Author(s):  
L. J. Janssen ◽  
P. M. O'Byrne ◽  
E. E. Daniel
Keyword(s):  
Airway Hyperresponsiveness ◽  
Electrical Field Stimulation ◽  
Progressive Decrease ◽  
Electrical Field ◽  
Thromboxane Receptor ◽  
Direct Measurements ◽  
Thromboxane Receptor Antagonist ◽  
Over Time

The effects of ozone inhalation on the contractility of canine bronchi and the mechanisms underlying any changes observed were investigated. Ozone inhalation caused acetylcholine airway hyperresponsiveness in vivo. Isolated segments of bronchi (3rd to 5th order) from dogs previously exposed to ozone (or normal air) were mounted in organ baths. Contractile responses to electrical field stimulation (FS) in all tissues decreased in magnitude over time (measured at 10, 120, 210, and 300 min after mounting tissues in the organ baths); responses to 150 mM KCl did not show such a progressive decrease. Ozone inhalation produced a dramatic enhancement of FS responses, a smaller enhancement of responses to carbachol (10(-8)-10(-4) M), and no change in responses to KCl (150 mM). In the presence of 10(-5) M indomethacin, all responses were enhanced and tended to increase in magnitude over time; indomethacin also abolished the differences in responsiveness between the control and ozone-exposed tissues. In the presence of the thromboxane receptor antagonist L-670,596 (10(-8) M), the magnitudes of all FS responses showed a progressive decrease over time while KCl responses did not; again, the differences in FS responses between control and ozone-exposed tissues were decreased or made insignificant. In conclusion, ozone produced airway hyperresponsiveness in vivo and hyperresponsiveness in canine bronchi in vitro via decreased prejunctional and postjunctional inhibition (likely mediated by prostaglandin E2) and increased prejunctional excitation mediated by thromboxane A2. However, direct measurements of mediator release should be carried out to reach a firm conclusion.

Allergen-induced airway hyperresponsiveness in Brown-Norway rat: role of parasympathetic mechanisms

1993 ◽  
Vol 75 (1) ◽  
pp. 279-284 ◽  
Author(s):  
W. Elwood ◽  
T. Sakamoto ◽  
P. J. Barnes ◽  
K. F. Chung
Keyword(s):  
Airway Hyperresponsiveness ◽  
Allergen Challenge ◽  
Electrical Field Stimulation ◽  
Airway Responsiveness ◽  
Brown Norway ◽  
Field Stimulation ◽  
Electrical Field ◽  
Norway Rat

Enhanced parasympathetic mechanisms may contribute to airway hyperresponsiveness. The present study examined whether the in vivo increase in airway responsiveness seen 18–24 h after either a single or chronic aerosolized allergen challenge protocol in actively sensitized Brown-Norway rats was due to altered parasympathetic mechanisms. The roles of central and reflex vagal mechanisms were studied by performing bilateral cervical vagotomy before measurement of airway responsiveness. Bilateral vagotomy failed to reduce the increase in airway responsiveness after either a single or chronic allergen challenge. The roles of increased neural release of acetylcholine (ACh) and increased end organ responsiveness were studied in vitro. The isometric responses of tracheal and bronchial strips to both electrical field stimulation and exogenously applied ACh from rats exposed both to single and chronic allergen challenges were compared with those from saline-exposed rats. The responses to electrical field stimulation and to exogenous ACh were not significantly enhanced 18–24 h after either protocol. We conclude that the airway hyperresponsiveness observed in this allergic rat model is not mediated through an enhancement of parasympathetic mechanisms.

Interaction of heparin and protamine in presence of overdosage: in vitro study

2020 ◽  
pp. 021849232095506
Author(s):  
Alexander A Hanke ◽  
Ines Severloh ◽  
Felix Flöricke ◽  
Christian F Weber ◽  
Thomas Lang
Keyword(s):  
In Vitro Study ◽  
Vitro Study ◽  
Clot Formation ◽  
Rotational Thromboelastometry ◽  
Significant Prolongation ◽  
Heparin Neutralization ◽  
Positive Effect ◽  
Clot Formation Time

Background Heparin is used for anticoagulation during cardiopulmonary bypass. After weaning from bypass, protamine is administered to neutralize the effects of heparin and thus reestablish hemostasis. Rotational thrombelastometry has been shown to discriminate between heparin and other impairing effects on coagulation. We analyzed the interaction of heparin and protamine under different conditions of overdosage in an in-vitro trial. Methods Blood samples were taken from 17 healthy volunteers, separated, and spiked in vitro with heparin, protamine for heparin neutralization, an overdosage of protamine, and two dosages of re-heparinization to evaluate heparin effects under the condition of protamine overdosage. All samples were analyzed in a standard ROTEM rotational thromboelastometry device after intrinsic activation with and without addition of heparinase. Coagulation time, maximum clot firmness, and clot formation time were recorded. Results Heparin led to prolongation of coagulation and clot formation times in the test without heparinase. Adequate protamine addition normalized the test, and overdosage of protamine led to significant prolongation of both times. Addition of heparin in the presence of protamine overdosage normalized these parameters. Conclusion We reconfirmed that the ROTEM device enables discrimination of the effects heparin and protamine on coagulation and detection of the coagulation-impairing effects of protamine overdosage. Furthermore, we were able to show a positive effect on coagulation times by heparin in the presence of protamine overdosage. Because this was an in-vitro study, these findings need to be confirmed in vivo, requiring further research.

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