Exploring feedback‐controlled versus open‐circuit electrochemical lipolysis in ex vivo and in vivo porcine fat: A feasibility study

Author(s):  
Andrew E. Heidari ◽  
Ellen M. Hong ◽  
Asher Park ◽  
Tiffany T. Pham ◽  
Earl Steward ◽  
...  
2020 ◽  
Vol 43 (1) ◽  
pp. 3-9
Author(s):  
Lucrezia Mazzantini ◽  
Mattia Dimitri ◽  
Fabio Staderini ◽  
Fabio Cianchi ◽  
Andrea Corvi

Ex vivo testing is a fundamental step in the development of new medical devices; indeed without it, it is impossible to proceed with in vivo tests. At the University of Florence, a robotic tool for microwave thermal ablation is under development. Up to now, the thermoablation tests for the validation of the tool were carried out on non-perfused ex vivo livers, providing results that inevitably differ from those obtainable with an in vivo liver. The aim is to design, and consequently create, a compact and transportable system which allows to perfuse a swine liver with physiological solution and heparin. This device should also allow the organ to be transported from the explantation place to the laboratory, keeping it under normothermal condition. The perfusor was designed to simulate the physiological flow within the liver in the most realistic way possible. The design, construction, and optimization of the perfusor have been addressed using the physiological values of hepatic flow and pressure identified in the literature, neglecting in the first instance any load losses. Therefore, open circuit tests were conducted, validated through perfusion tests on freshly explanted pig liver; during these tests, the surface temperature of the organ was recorded using an infrared camera, and the fluid temperature was verified using an immersion probe. The perfusion test showed a good alignment with the open circuit tests, demonstrating the validity of the simplifications adopted to treat the complex vascular structure of the liver.


2017 ◽  
Vol 05 (08) ◽  
pp. E775-E783 ◽  
Author(s):  
Liang Lim ◽  
Catherine Streutker ◽  
Norman Marcon ◽  
Maria Cirocco ◽  
Alexandra Lao ◽  
...  

Abstract Background and study aims Accurate endoscopic detection of dysplasia in patients with Barrett’s esophagus (BE) remains a major clinical challenge. The current standard is to take multiple biopsies under endoscopic image guidance, but this leaves the majority of the tissue unsampled, leading to significant risk of missing dysplasia. Furthermore, determining whether there is submucosal invasion is essential for proper staging. Hence, there is a clinical need for a rapid in vivo wide-field imaging method to identify dysplasia in BE, with the capability of imaging beyond the mucosal layer. We conducted an ex vivo feasibility study using photoacoustic imaging (PAI) in patients undergoing endoscopic mucosal resection (EMR) for known dysplasia. The objective was to characterize the esophageal microvascular pattern, with the long-term goal of performing in vivo endoscopic PAI for dysplasia detection and therapeutic guidance. Materials and methods EMR tissues were mounted luminal side up. The tissues were scanned over a field of view of 14 mm (width) by 15 mm (depth) at 680, 750, and 850 nm (40 MHz acoustic central frequency). Ultrasound and photoacoustic images were simultaneously acquired. Tissues were then sliced and fixed in formalin for histopathology with hematoxylin and eosin staining. A total of 13 EMR specimens from eight patients were included in the analysis, which consisted of co-registration of the photoacoustic images with corresponding pathologist-classified histological images. We conducted mean difference test of the total hemoglobin distribution between tissue classes. Results Dysplastic and nondysplastic BE can be distinguished from squamous tissue in 84 % of region-of-interest comparisons (42/50). However, the ability of intrinsic PAI to distinguish dysplasia from NDBE, which is the clinically important challenge, was only about 33 % (10/30). Conclusion We demonstrated the technical feasibility of this approach. Based on our ex vivo data, changes in total hemoglobin content from intrinsic PAI (i. e. without exogenous contrast) can differentiate BE from squamous esophageal mucosa. However, most likely intrinsic PAI is unable to differentiate dysplastic from nondysplastic BE with adequate sensitivity for clinical translation.


Endoscopy ◽  
2015 ◽  
Vol 47 (09) ◽  
pp. 820-824 ◽  
Author(s):  
Ryu Nakadate ◽  
Shotaro Nakamura ◽  
Tomohiko Moriyama ◽  
Hajime Kenmotsu ◽  
Susumu Oguri ◽  
...  

2020 ◽  
Vol 4 (12) ◽  
pp. 2768-2778 ◽  
Author(s):  
Michael A. Spinner ◽  
Alexey Aleshin ◽  
Marianne T. Santaguida ◽  
Steven A. Schaffert ◽  
James L. Zehnder ◽  
...  

Abstract Precision medicine approaches such as ex vivo drug sensitivity screening (DSS) are appealing to inform rational drug selection in myelodysplastic syndromes (MDSs) and acute myeloid leukemia, given their marked biologic heterogeneity. We evaluated a novel, fully automated ex vivo DSS platform that uses high-throughput flow cytometry in 54 patients with newly diagnosed or treatment-refractory myeloid neoplasms to evaluate sensitivity (blast cytotoxicity and differentiation) to 74 US Food and Drug Administration–approved or investigational drugs and 36 drug combinations. After piloting the platform in 33 patients, we conducted a prospective feasibility study enrolling 21 patients refractory to hypomethylating agents (HMAs) to determine whether this assay could be performed within a clinically actionable time frame and could accurately predict clinical responses in vivo. When assayed for cytotoxicity, ex vivo drug sensitivity patterns were heterogeneous, but they defined distinct patient clusters with differential sensitivity to HMAs, anthracyclines, histone deacetylase inhibitors, and kinase inhibitors (P < .001 among clusters) and demonstrated synergy between HMAs and venetoclax (P < .01 for combinations vs single agents). In our feasibility study, ex vivo DSS results were available at a median of 15 days after bone marrow biopsy, and they informed personalized therapy, which frequently included venetoclax combinations, kinase inhibitors, differentiative agents, and androgens. In 21 patients with available ex vivo and in vivo clinical response data, the DSS platform had a positive predictive value of 0.92, negative predictive value of 0.82, and overall accuracy of 0.85. These data demonstrate the utility of this approach for identifying potentially useful and often novel therapeutic drugs for patients with myeloid neoplasms refractory to standard therapies.


Author(s):  
Jiawei Ge ◽  
Justin D. Opfermann ◽  
Hamed Saeidi ◽  
Katherine A. Huenerberg ◽  
Christopher D. Badger ◽  
...  

Surgical tumor resection is a common approach to cancer treatment. India Ink tattoos are widely used to aid tumor resection by localizing and mapping the tumor edge at the surface. However, India Ink tattoos are easily obscured during electrosurgical resection, and fade in intensity over time. In this work, a novel near-infrared (NIR) fluorescent marker is introduced as an alternative. The NIR marker was made by mixing indocyanine green (ICG), biocompatible cyanoacrylate, and acetone. The marking strategy was evaluated in a chronic ex vivo feasibility study using porcine tissues, followed by a chronic in vivo mouse study while compared with India Ink. In both studies, signal-to-noise (SNR) ratios and dimensions of the NIR markers and/or India Ink over the study period were calculated and reported. Electrocautery was performed on the last day of the mouse study after mice were euthanized, and SNR ratios and dimensions were quantified and compared. Biopsy was performed at all injection sites and slides were examined by a pathologist. The proposed NIR marker achieved (i) consistent visibility in the 26-day feasibility study and (ii) improved durability, visibility, and biocompatibility when compared to traditional India Ink over the six-week period in an in vivo mouse model. These effects persist after electrocautery whereas the India Ink markers were obscured. The use of a NIR fluorescent presurgical marking strategy has the potential for intraoperative tracking during long-term treatment protocols.


2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito

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.


2010 ◽  
Vol 58 (S 01) ◽  
Author(s):  
S Wipper ◽  
Y von Rittberg ◽  
J Lindner ◽  
C Pahrmann ◽  
H Reichenspurner ◽  
...  

1994 ◽  
Vol 71 (01) ◽  
pp. 095-102 ◽  
Author(s):  
Désiré Collen ◽  
Hua Rong Lu ◽  
Jean-Marie Stassen ◽  
Ingrid Vreys ◽  
Tsunehiro Yasuda ◽  
...  

SummaryCyclic Arg-Gly-Asp (RGD) containing synthetic peptides such as L-cysteine, N-(mercaptoacetyl)-D-tyrosyl-L-arginylglycyl-L-a-aspartyl-cyclic (1→5)-sulfide, 5-oxide (G4120) and acetyl-L-cysteinyl-L-asparaginyl-L-prolyl-L-arginyl-glycyl-L-α-aspartyl-[0-methyltyrosyl]-L-arginyl-L-cysteinamide, cyclic 1→9-sulfide (TP9201) bind with high affinity to the platelet GPIIb/IIIa receptor.The relationship between antithrombotic effect, ex vivo platelet aggregation and bleeding time prolongation with both agents was studied in hamsters with a standardized femoral vein endothelial cell injury predisposing to platelet-rich mural thrombosis, and in dogs with a carotid arterial eversion graft inserted in the femoral artery. Intravenous administration of G4120 in hamsters inhibited in vivo thrombus formation with a 50% inhibitory bolus dose (ID50) of approximately 20 μg/kg, ex vivo ADP-induccd platelet aggregation with ID50 of 10 μg/kg, and bolus injection of 1 mg/kg prolonged the bleeding time from 38 ± 9 to 1,100 ± 330 s. Administration of TP9201 in hamsters inhibited in vivo thrombus formation with ID50 of 30 μg/kg, ex vivo platelet aggregation with an ID50 of 50 μg/kg and bolus injection of 1 mg/kg did not prolong the template bleeding time. In the dog eversion graft model, infusion of 100 μg/kg of G4120 over 60 min did not fully inhibit platelet-mediated thrombotic occlusion but was associated with inhibition of ADP-induccd ex vivo platelet aggregation and with prolongation of the template bleeding time from 1.3 ± 0.4 to 12 ± 2 min. Infusion of 300 μg/kg of TP9201 over 60 min completely prevented thrombotic occlusion, inhibited ex vivo platelet aggregation, but was not associated with prolongation of the template bleeding time.TP9201, unlike G4120, inhibits in vivo platelet-mediated thrombus formation without associated prolongation of the template bleeding time.


Sign in / Sign up

Export Citation Format

Share Document