Intravenous infusion of trieicosapentaenoyl-glycerol and LTB4 and LTB5 production by leukocytes of rabbits

1992 ◽  
Vol 262 (6) ◽  
pp. H1711-H1718
Author(s):  
S. Sawazaki ◽  
N. Nakamura ◽  
T. Hamazaki ◽  
K. Yamazaki ◽  
M. Urakaze ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Tissue Damage ◽  
Polymorphonuclear Leukocytes ◽  
Ex Vivo ◽  
Leukotriene B4 ◽  
Control Groups ◽  
Oil Emulsion ◽  
Ltb4 Production ◽  
Ex Vivo Study ◽  
Determining Factor

During myocardial infarction leukotriene B4 (LTB4) is probably a major determining factor of tissue damage because it can amplify the inflammatory reaction by recruiting leukocytes and degranulating them. Oral administration of eicosapentaenoic acid (EPA) is known to reduce LTB4 production by polymorphonuclear leukocytes (PMNL). However, it takes several weeks for EPA to take effect. In this study, we formulated a trieicosapentaenoyl-glycerol emulsion and infused it into rabbits (0.8 g EPA/kg). In the ex vivo study, the inhibition of LTB4 production by PMNL from EPA-infused rabbits was maximal (32-60% of preinfusion values, P less than 0.01) 6 h after the infusion. There was also a tendency toward reduced LTB4 production 1, 24, and 168 h after the infusion. A lower dose (0.2 g EPA/kg) also reduced LTB4 production (45% of preinfusion values, P less than 0.02) 6 h after the infusion. There was no significant change in LTB4 production in control groups in which soybean oil emulsion was infused instead of EPA. EPA infusion might be useful for reduction of tissue damage in the acute phase of LTB4-related diseases such as acute myocardial infarction.

Leukotriene B4 production in healthy subjects carrying variants of the arachidonate 5-lipoxygenase-activating protein gene associated with a risk of myocardial infarction

2007 ◽  
Vol 112 (7) ◽  
pp. 411-416 ◽  
Author(s):  
Annette Maznyczka ◽  
Massimo Mangino ◽  
Andrew Whittaker ◽  
Peter Braund ◽  
Tom Palmer ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Healthy Subjects ◽  
Calcium Ionophore ◽  
Population Based ◽  
Leukotriene B4 ◽  
Calcium Ionophore A23187 ◽  
Ionophore A23187 ◽  
Blood Neutrophils ◽  
Ltb4 Production ◽  
Main Regulator

Leukotrienes are implicated in the pathogenesis of coronary artery disease. Recently two haplotypes (HapA and HapB) in the gene encoding ALOX5AP (arachidonate 5-lipoxygenase-activating protein), the main regulator of 5-lipoxygenase, have been associated with a doubling of the risk of myocardial infarction. Studies have also shown that treatment with a leukotriene inhibitor reduces biomarkers of coronary risk in patients carrying HapA, raising the possibility of developing genotype-specific therapy. In the present study, we examined whether carriage of HapA or HapB is associated with increased LTB4 (leukotriene B4) production in healthy subjects. Age- and gender-matched healthy HapA carriers (n=21), HapB carriers (n=20) and non-A/non-B carriers (n=18), with no reported history of cardiovascular disease, were recruited following DNA screening of 1268 subjects from a population-based study. Blood neutrophils were isolated, and LTB4 production was measured in response to stimulation with 1 μmol/l of the calcium ionophore A23187. There was no difference in the mean level for LTB4 production in the three groups (non-A/non-B, 24.9±8.3 ng/106 cells; HapA, 22.2±11.9 ng/106 cells; HapB, 19.8±4.8 ng/106; P=0.14). The findings indicate that if either the HapA or the HapB haplotype of ALOX5AP indeed increases cardiovascular risk, then the mechanism is not simply due to a systematically observable effect of the haplotype on LTB4 production in response to stimulation. The results suggest that knowledge of a patient's haplotype may not provide useful information on the probable clinical response to ALOX5AP inhibitors.

scholarly journals Comparative Analysis of Different Flavonoids on the Immediate Shear Bond Strength of Bleached Enamel Surface: An ex-vivo Study

2021 ◽  
Vol 5 (3) ◽  
pp. OR1-OR5
Author(s):  
Nidhi Shrivastava ◽  
Marisha Bhandari
Keyword(s):  
Comparative Analysis ◽  
Bond Strength ◽  
Green Tea ◽  
Shear Bond Strength ◽  
Ex Vivo ◽  
Grape Seed ◽  
Positive Control ◽  
Sodium Ascorbate ◽  
Control Groups ◽  
Ex Vivo Study

INTRODUCTION: Bleaching, although considered as the first choice of treatment for discoloured teeth, can be utilized in conjunction with composite resin bonding or veneering and porcelain laminate veneers, to provide a more esthetic result. AIM: The aim of the ex-vivo study is to obtain a comparative analysis to evaluate the effectiveness of antioxidants on the immediate composite bond strength on bleached enamel surface.MATERIALS AND METHOD: Freshly extracted human permanent maxillary central incisors were selected and prepared for the respective study. All the specimens then were randomly divided into two control groups and three experimental groups, each group consisting of 20 specimens each. Among these were three experimental groups 10% Sodium Ascorbate, 5% Grape Seed extracts (Proanthocyanidin, PA) & 10% Green tea extracts (catechins and epigallocatechin gallate, CA and EG) and two control groups (Positive control & Negative control).RESULTS: When compared to Group 1 (positive control, 26.24 ± 0.90 MPa ), Group 3 (5%Grape seed extract; 32.17 ± 1.52 MPa), Group 4 (10% Sodium Ascorbate; 28.91 ±1.50 MPa ) and Group 5 (5% Green tea extract; 24.10 ± 1.21MPa ) showed significantly higher shear bond strength values.CONCLUSION: The present study indicated that the shear bond strength of the antioxidant group (Group3) is higher than all three experimental groups. In addition, the shear bond strength of the bleached group (Group 2) is significantly lower than all the other groups. This implies that immediate use of antioxidants, contributes in reversal the bond strength of bleached enamel.

Plasminogen Depletion during Streptokinase Treatment or Two-Chain Urokinase Incubation Correlates with Decreased Clot Lysability Ex Vivo and In Vitro

1993 ◽  
Vol 70 (06) ◽  
pp. 0998-1004 ◽  
Author(s):  
Páll T Önundarson ◽  
H Magnús Haraldsson ◽  
Lena Bergmann ◽  
Charles W Francis ◽  
Victor J Marder
Keyword(s):  
Myocardial Infarction ◽  
Ex Vivo ◽  
Time Dependent ◽  
State Variables ◽  
Thrombolytic Treatment ◽  
Direct Proportion ◽  
Plasmin Activity ◽  
Plasma Exposure ◽  
The Relationship

SummaryThe relationship between lytic state variables and ex vivo clot lysability was investigated in blood drawn from patients during streptokinase administration for acute myocardial infarction. A lytic state was already evident after 5 min of treatment and after 20 min the plasminogen concentration had decreased to 24%, antiplasmin to 7% and fibrinogen 0.2 g/1. Lysis of radiolabeled retracted clots in the patient plasmas decreased from 37 ± 8% after 5 min to 21 ± 8% at 10 min and was significantly lower (8 ± 9%, p <0.005) in samples drawn at 20, 40 and 80 min. Clot lysability correlated positively with the plasminogen concentration (r = 0.78, p = 0.003), but not with plasmin activity. Suspension of radiolabeled clots in normal plasma pre-exposed to 250 U/ml two-chain urokinase for varying time to induce an in vitro lytic state was also associated with decreasing clot lysability in direct proportion with the duration of prior plasma exposure to urokinase. The decreased lysability correlated with the time-dependent reduction in plasminogen concentration (r = 0.88, p <0.0005). Thus, clot lysability decreases in conjunction with the development of the lytic state and the associated plasminogen depletion. The lytic state may therefore limit reperfusion during thrombolytic treatment.

The Quantitation of Platelet Aggregation Induced by Four Compounds: A Study in Relation to Myocardial Infarction

1966 ◽  
Vol 16 (03/04) ◽  
pp. 752-767 ◽  
Author(s):  
J. R O’Brien ◽  
F. C Path ◽  
Joan B. Heywood ◽  
J. A Heady
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Platelet Aggregation ◽  
Platelet Rich Plasma ◽  
Myocardial Infarct ◽  
Control Groups ◽  
The Mean ◽  
Platelet Shape

SummaryMethods for measuring and comparing day to day differences in the response of platelet aggregation in platelet-rich plasma to added ADP, 5-H.T., adrenaline and collagen are reported. Platelet aggregation induced by ADP, 5-H.T. and adrenaline was studied in patients with acute myocardial infarction and in others 3 months to 5 years after an infarct; some were receiving anti-coagulants and others not: these three groups were compared with three control groups. The mean platelet shape was rounder and the response to ADP and to 5-H.T. and one parameter of the response to adrenaline was significantly greater in all groups of patients with myocardial infarct taken together than in the controls. The platelet-rich plasma from patients with recent infarction were most responsive to ADP and 5-H.T. immediately after the infarct. Anti-coagulants had no effect on these tests. However, there was wide variation within the individuals and much overlap between groups, and these tests can only reliably distinguish between groups and not between individuals. The significance of these findings is discussed.

Direct Visualization of A2, A3, and A4 Finger Flexor Pulley Injuries at 3-T and 7-T MRI: An Ex Vivo Study

2020 ◽  
Author(s):  
Rafael Heiss ◽  
Frank W. Roemer ◽  
Christoph Lutter ◽  
Rolf Janka ◽  
Volker Schöffl ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Direct Visualization ◽  
Ex Vivo Study

Impact of metal artefacts in QCT of the hip caused by a contralateral Gamma type nail: an ex vivo study

2014 ◽  
Author(s):  
Klaus Engelke ◽  
Nicolas Bouler ◽  
Oleg Museyko Fuerst ◽  
Sebastien Parratte ◽  
Thomas Fuerst ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Metal Artefacts ◽  
Ex Vivo Study

Interactions between programmable shunt valves and magnetically controlled growing rods for scoliosis

2020 ◽  
Vol 26 (6) ◽  
pp. 667-670
Author(s):  
Thomas Larrew ◽  
Mohammed Alshareef ◽  
Robert F. Murphy ◽  
Ramin Eskandari ◽  
Libby Kosnik Infinger
Keyword(s):  
Remote Control ◽  
Ex Vivo ◽  
Shunt Valve ◽  
Growing Rods ◽  
Growing Rod ◽  
Before And After ◽  
Magnetically Controlled Growing Rods ◽  
Ex Vivo Study

OBJECTIVEAlthough the advent of magnetic growing rod technology for scoliosis has provided a means to bypass multiple hardware lengthening operations, it is important to be aware that many of these same patients have a codiagnosis of hydrocephalus with magnet-sensitive programmable ventricular shunts. As the magnetic distraction of scoliosis rods has not previously been described to affect the shunt valve setting, the authors conducted an investigation to characterize the interaction between the two devices.METHODSIn this ex vivo study, the authors carried out 360 encounters between four different shunt valve types at varying distances from the magnetic external remote control (ERC) used to distract the growing rods. Valve settings were examined before and after every interaction with the remote control to determine if there was a change in the setting.RESULTSThe Medtronic Strata and Codman Hakim valves were found to have setting changes at distances of 3 and 6 inches but not at 12 inches. The Aesculap proGAV and Codman Certas valves, typically described as MRI-resistant, did not have any setting changes due to the magnetic ERC regardless of distance.CONCLUSIONSAlthough it is not necessary to check a shunt valve after every magnetic distraction of scoliosis growing rods, if there is concern that the magnetic ERC may have been within 12 inches (30 cm) of a programmable ventricular shunt valve, the valve should be checked at the bedside with a programmer or with a skull radiograph along with postdistraction scoliosis radiographs.

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