scholarly journals New Biparietal Bipolar Catheter Prototype for Hybrid Atrial Fibrillation Ablation

2021 ◽  
pp. 155698452098102
Author(s):  
Francesco Matteucci ◽  
Bart Maesen ◽  
Carlo De Asmundis ◽  
Gianmarco Parise ◽  
Linda Renata Micali ◽  
...  
Keyword(s):  
Left Atrium ◽  
Ex Vivo ◽  
Pulmonary Veins ◽  
Computer Software ◽  
Maximum Length ◽  
Linear Lesions ◽  
Custom Made ◽  
In Parenthesis ◽  
Neodymium Magnets

Objective To evaluate the size and depth of linear lesions by in vitro testing with a custom-made radio frequency biparietal bipolar ablation catheter in a single-stage setting. Methods A custom-made catheter was created to generate linear lesions around the left atrium and pulmonary veins of an ex vivo pig. Two frames were made, 1 epicardial and 1 endocardial. A continuous copper braid electrode and an alignment system consisting of 2 parallel rows of neodymium magnets were embedded in a flexible plastic support. After 24 hours of formalin conservation, samples of the left atrium of a freshly slaughtered pig were sliced in a cryotome, thus obtaining a sequence of 100-µm thick layers extending from the endocardial to the epicardial side. After being digitized through a scanner, these layers were evaluated using morphometric computer software. For each slice, we evaluated the maximum length of the lesions, the maximum epicardial length, the maximum endocardial length, the total area of the lesion, and the total volume. Results Forty transmural lesions from 40 specimens were obtained. The results were the following (the number in parenthesis is the interquartile range in mm): lesion maximum length ( L MAX) was 7.297 mm (0.006), epicardial maximum length ( L EPI) was 7.291 mm (0.014), and endocardial maximum length was 7.291 mm (0.018). The total area and total volume were 1018.50 ± 36.51 mm2 and 101.85 ± 3.65 mm3, respectively. Conclusions Our prototype showed very promising results. The next step will be to enhance the design for clinical application.

Effects of the Tibetan herbal preparation PADMA 28 on blood lipids and lipid oxidisability in subjects with mild hypercholesterolaemia

VASA ◽  
2005 ◽  
Vol 34 (1) ◽  
pp. 11-17 ◽  
Author(s):  
Brunner-La Rocca ◽  
Schindler ◽  
Schlumpf ◽  
Saller ◽  
Suter
Keyword(s):  
Endothelial Dysfunction ◽  
Blood Lipids ◽  
Ex Vivo ◽  
Hdl Cholesterol ◽  
Blood Lipid ◽  
Tibetan Medicine ◽  
Double Blind ◽  
Intraarterial Infusion ◽  
Padma 28

Background: Previous studies showed an anti-atherosclerotic effect of PADMA 28, an herbal formula based on Tibetan medicine. As the mechanisms of action are not fully understood, we investigated whether PADMA 28 may lower blood lipids and lipid oxidisability, and affect early endothelial dysfunction. Patients and methods: Sixty otherwise healthy subjects with total cholesterol ≥5.2 mmol/l and < 8.0 mmol/l were randomly assigned to placebo or PADMA 28, 3 x 2 capsules daily, for 4 weeks (double-blind). Blood lipids (total, LDL-, and HDL-cholesterol, triglycerides, Apo-lipoprotein A1 and B) and ex vivo lipid oxidisability were measured before and after treatment. In a subset of 24 subjects, endothelial function was assessed using venous occlusion plethysmography with intraarterial infusion of acetylcholine. Isolated LDL and plasma both untreated and pre-treated with PADMA 28 extract were oxidised by the radical generator AAPH. Conjugated diene formation was measured at 245 nm. Results: Blood lipids did not change during the study in both groups. In contrast to previous reports in mild hypercholesterolaemia, no endothelial dysfunction was seen and, consequently, was not influenced by therapy. Ex vivo blood lipid oxidisability was significantly reduced with PADMA 28 (area under curve: 5.29 ± 1.62 to 4.99 ± 1.46, p = 0.01), and remained unchanged in the placebo group (5.33 ± 1.88 to 5.18 ± 1.78, p > 0.1). This effect persisted one week after cessation of medication. In vitro experiments confirmed the prevention of lipid peroxidation in the presence of PADMA 28 extracts. Persistent protection was also seen for LDL isolated from PADMA 28-pretreated blood after being subjected to rigorous purification. Conclusions: This study suggests that the inhibition of blood lipid oxidisability by PADMA 28 may play a role in its anti-atherosclerotic effect.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

In-vitro/ex-vivo HIPEC-Modelle zur Therapieeffizienzprüfung

2013 ◽  
Vol 51 (08) ◽  
Author(s):  
C Ulmer ◽  
L Schaaf ◽  
W Zopf ◽  
W Steurer
Keyword(s):  
Ex Vivo

Kontrolle der erhöhten ex vivo Th1/Th2-Aktivität bei Asthma durch Omalizumab in vitro

Pneumologie ◽  
2017 ◽  
Vol 71 (S 01) ◽  
pp. S1-S125
Author(s):  
G Ulrich-Merzenich ◽  
LJ Juergens ◽  
A Shcherbakova ◽  
A Tüschen ◽  
I Tuleta ◽  
...  
Keyword(s):  
Ex Vivo

Significance of Platelet β-Adrenoceptors for Platelet Responses In Vivo and In Vitro

1992 ◽  
Vol 68 (06) ◽  
pp. 687-693 ◽  
Author(s):  
P T Larsson ◽  
N H Wallén ◽  
A Martinsson ◽  
N Egberg ◽  
P Hjemdahl
Keyword(s):  
Ex Vivo ◽  
High Dose ◽  
Platelet Aggregability ◽  
Adrenoceptor Agonist ◽  
Dose Infusion ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Factor Antigen

SummaryThe significance of platelet β-adrenoceptors for platelet responses to adrenergic stimuli in vivo and in vitro was studied in healthy volunteers. Low dose infusion of the β-adrenoceptor agonist isoprenaline decreased platelet aggregability in vivo as measured by ex vivo filtragometry. Infusion of adrenaline, a mixed α- and β-adrenoceptor agonist, increased platelet aggregability in vivo markedly, as measured by ex vivo filtragometry and plasma β-thromboglobulin levels. Adrenaline levels were 3–4 nM in venous plasma during infusion. Both adrenaline and high dose isoprenaline elevated plasma von Willebrand factor antigen levels β-Blockade by propranolol did not alter our measures of platelet aggregability at rest or during adrenaline infusions, but inhibited adrenaline-induced increases in vWf:ag. In a model using filtragometry to assess platelet aggregability in whole blood in vitro, propranolol enhanced the proaggregatory actions of 5 nM, but not of 10 nM adrenaline. The present data suggest that β-adrenoceptor stimulation can inhibit platelet function in vivo but that effects of adrenaline at high physiological concentrations are dominated by an α-adrenoceptor mediated proaggregatory action.

In Vivo Effect of Suloctidil as an Antiplatelet Agent

1979 ◽  
Vol 41 (03) ◽  
pp. 465-474 ◽  
Author(s):  
Marcia R Stelzer ◽  
Thomas S Burns ◽  
Robert N Saunders
Keyword(s):  
Ex Vivo ◽  
Antiplatelet Agent ◽  
Ratio Method ◽  
Platelet Aggregate ◽  
Permanent Effect ◽  
Platelet Aggregates ◽  
5 Ht Uptake ◽  
High Doses

SummaryThe relationship between the effects of suloctidil in vivo as an antiplatelet agent and in vitro as a modifier of platelet serotonin (5-HT) parameters was investigated. Suloctidil was found to be effective in reducing platelet aggregates formation in the retired breeder rat as determined using the platelet aggregate ratio method (PAR) with an ED50 of 16.1 mg/kg 24 hours post administration. In contrast to the hypothesis that 5-HT depletion is involved in the anti-aggregatory mechanism of suloctidil, no correlation was found between platelet 5- HT content and this antiplatelet activity. Reduction of platelet 5-HT content required multiple injections of high doses (100 mg/kg/day) of suloctidil. Suloctidil administration for 8 days at 100 mg/kg/day, which lowered platelet 5-HT content by 50%, resulted in no permanent effect on ex vivo platelet 5-HT uptake or thrombin-induced release, nor alteration in the plasma 5-HT level. However, these platelets exhibited a short-lived, significant increase in percent leakage of 5-HT after 30 minutes of incubation. Therefore, suloctidil treatment at high doses may with time result in platelet 5-HT depletion, however this effect is probably not related to the primary anti-aggregatory activity of the drug.

Monitoring Heparin Therapy: Relationships between the Activated Partial Thromboplastin Time and Heparin Assays Based on Ex-Vivo Heparin Samples

1990 ◽  
Vol 63 (01) ◽  
pp. 016-023 ◽  
Author(s):  
A M H P van den Bessekaar ◽  
J Meeuwisse-Braun ◽  
R M Bertina
Keyword(s):  
Partial Thromboplastin Time ◽  
Plasma Sample ◽  
Ex Vivo ◽  
Correlation Coefficients ◽  
Heparin Therapy ◽  
Thromboembolic Disease ◽  
Activated Partial Thromboplastin Time ◽  
Venous Thromboembolic Disease ◽  
Venous Thromboembolic

SummaryFive different APTT reagents, two amidolytic anti-ITa assays, one amidoiytic anti-Xa assay, and one coagulometric anti-Xa/ anti-IIa assay were used to assess the effect of heparin in patients treated for venous thromboembolic disease. Good correlations were observed between lug-transformed APYE> determined with the various reagents (correlation coefficients: 0.92-0.96).Nevertheless there were important differences in the slopes of the lines of relationship between the APTT reagents.Good correlations were observed between the anti-Xa and anti-IIa assay results (correlation coefficients: 0.92-0.97). However, the amidolytic anti-Xa activity was significantly higher (p <0.001) than the two amidolytic anti-IIa activities. Less good correlations were observed between the log-transformed APTTs and the anti-Xa or anti-IIa activities (correlation coefficients: 0.64-0.78). The correlations were improved by transforming the APTT into APTT-ratio, i.e. the ratio of the patient’s APTT to the same patient’s APTT after removal of heparin from the plasma sample by means of ECTEOLA-cellulose treatment. The correlation coefficients of log (AFTT-ratio) with anti-Xa or anti-IIa ranged from 0.76 to 0.87.For both APTT and amidolytic heparin assay, the response to in vitro heparin was different from the response to ex vivo heparin.Therefore, equivalent therapeutic ranges should be assessed by using ex vivo samples rather than in vitro heparin. Because of the response differences between the APTT reagents, it is not adequate to define a therapeutic range for heparin therapy without specification of the reagent.

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.

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