scholarly journals Effect of sugar metabolite methylglyoxal on equine lamellar explants: An ex vivo model of laminitis

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0253840
Author(s):  
Cristina Vercelli ◽  
Massimiliano Tursi ◽  
Silvia Miretti ◽  
Gessica Giusto ◽  
Marco Gandini ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Tissue Inhibitor Of Metalloproteinase ◽  
Carbonyl Stress ◽  
Dihydroxyacetone Phosphate ◽  
High Concentration ◽  
Ex Vivo Model ◽  
Experimental Conditions ◽  
Irreversible Damage ◽  
Tissue Samples ◽  
Separation Force

Laminitis is one of the most devastating diseases in equine medicine, and although several etiopathogenetic mechanisms have been proposed, few clear answers have been identified to date. Several lines of evidence point towards its underlying pathology as being metabolism-related. In the carbonyl stress pathway, sugars are converted to methylglyoxal (MG)—a highly reactive α-oxoaldehyde, mainly derived during glycolysis in eukaryotic cells from the triose phosphates: D-glyceraldehyde-3-phosphate and dihydroxyacetone phosphate. One common hypothesis is that MG could be synthesized during the digestive process in horses, and excessive levels absorbed into peripheral blood could be delivered to the foot and lead to alterations in the hoof lamellar structure. In the present study, employing an ex vivo experimental design, different concentrations of MG were applied to hoof explants (HE), which were then incubated and maintained in a specific medium for 24 and 48 h. Macroscopic and histological analyses and a separation force test were performed at 24 and 48 h post-MG application. Gene expression levels of matrix metalloproteinase (MMP)-2 and -14 and tissue inhibitor of metalloproteinase (TIMP)-2 were also measured at each time point for all experimental conditions. High concentrations of MG induced macroscopic and histological changes mimicking laminitis. The separation force test revealed that hoof tissue samples incubated for 24 h in a high concentration of MG, or with lower doses but for a longer period (48 h), demonstrated significant weaknesses, and samples were easily separated. All results support that high levels of MG could induce irreversible damage in HEs, mimicking laminitis in an ex vivo model.

scholarly journals In Vitro and Ex Vivo Activities of Minocycline and EDTA against Microorganisms Embedded in Biofilm on Catheter Surfaces

2003 ◽  
Vol 47 (11) ◽  
pp. 3580-3585 ◽  
Author(s):  
Issam Raad ◽  
Ioannis Chatzinikolaou ◽  
Gassan Chaiban ◽  
Hend Hanna ◽  
Ray Hachem ◽  
...  
Keyword(s):  
Low Dose ◽  
Ex Vivo ◽  
Bacterial Colonization ◽  
Rabbit Model ◽  
Confocal Laser ◽  
High Dose ◽  
High Concentration ◽  
Ex Vivo Model ◽  
Highly Active

ABSTRACT Minocycline-EDTA (M-EDTA) flush solution has been shown to prevent catheter-related infection and colonization in a rabbit model and in hemodialysis patients. We undertook this study in order to determine the activities of M-EDTA against organisms embedded in fresh biofilm (in vitro) and mature biofilm (ex vivo). For the experiment with the in vitro model, a modified Robbin’s device (MRD) was used whereby 25 catheter segments were flushed for 18 h with 106 CFU of biofilm-producing Staphylococcus epidermidis, Staphyloccocus aureus, and Candida albicans per ml. Subsequently, each of the catheter segments was incubated in one of the following solutions: (i) streptokinase, (ii) heparin, (iii) broth alone, (iv) vancomycin, (v) vancomycin-heparin, (vi) EDTA, (vii) minocycline (high-dose alternating with low-dose), or (viii) M-EDTA (low-dose minocycline alternating with high-dose minocycline were used to study the additive and synergistic activities of M-EDTA). All segments were cultured quantitatively by scrape sonication. For the experiment with the ex vivo model, 54 catheter tip segments removed from patients and colonized with bacterial organisms by roll plate were longitudinally cut into two equal segments and exposed to either saline, heparin, EDTA, or M-EDTA (with high-dose minocycline). Subsequently, all segments were examined by confocal laser electron microscopy. In the in vitro MRD model, M-EDTA (with a low concentration of minocycline) was significantly more effective than any other agent in reducing colonization of S. epidermidis, S. aureus, and C. albicans (P < 0.01). M-EDTA (with a high concentration of minocycline) eradicated all staphylococcal and C. albicans organisms embedded in the biofilm. In the ex vivo model, M-EDTA (with a high concentration of minocycline) reduced bacterial colonization more frequently than EDTA or heparin (P < 0.01). We concluded that M-EDTA is highly active in eradicating microorganisms embedded in fresh and mature biofilm adhering to catheter surfaces.

scholarly journals P048 A NEW MODALITY FOR BIOMECHANICAL VALIDATION OF CLOSURE TECHNIQUES OF LAPAROTOMIES

2021 ◽  
Vol 108 (Supplement_8) ◽  
Author(s):  
Floris den Hartog ◽  
Dimitri Sneiders ◽  
John Vlot ◽  
Gert-Jan Kleinrensink ◽  
Johannes Jeekel ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Tissue Sample ◽  
Speckle Pattern ◽  
Tensile Load ◽  
Suture Technique ◽  
Fascial Closure ◽  
Ex Vivo Model ◽  
Tissue Samples ◽  
Pulling Forces ◽  
Set Up

Abstract Aim Incisional hernia remains one of the most frequent complications after abdominal surgery. Several closure techniques exist. However, fundamental biomechanical understanding of these techniques and of the differences in clinical outcomes are still lacking. It is thought that distribution of lateral forces on the midline plays a role. Testing in a clinical setting is limited by sample sizes, costs and ethical regulations. We propose a preclinical ex vivo model in which multiple closure configurations can be tested in a controlled setting, eliminating interfering variables existing in previously published, more complex abdominal wall models. Consequently, this allows a valid comparison between closure modalities based on biomechanical merits. Material and Methods The experimental set-up is represented by a vertical tensile load tester, in which a sutured tissue sample is clamped. The tissue samples are covered with a fine, random speckle pattern via miniscule ink droplets. A high-resolution camera captures the speckles as the tissue is subjected to linear pulling forces. Image analysis documenting relative movement of speckles as a means for measuring tissue deformation is performed in ex-vivo tissue samples, resulting in specific objective biomechanical characteristics for each closure configuration. Results Local tissue strain fields are visualized, and compared between closure modalities and correlated to known linear forces applied to the tissue. The latest results will be shared and discussed. Conclusions A new modality for biomechanical evaluation of closure techniques has been developed. Further validation and serial experiments with different closure modalities with and without mesh reinforcement can be performed in order to determine the biomechanically optimal suture-technique for fascial closure.

scholarly journals Optimizing a reliable ex vivo human blood model to analyze expression of Staphylococcus epidermidis genes

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9295
Author(s):  
Susana Brás ◽  
Ângela França ◽  
Nuno Cerca
Keyword(s):  
Gene Expression ◽  
Antimicrobial Activity ◽  
Human Blood ◽  
Staphylococcus Epidermidis ◽  
Ex Vivo ◽  
Bacterial Concentration ◽  
Ex Vivo Model ◽  
Experimental Conditions ◽  
Experimental Parameters ◽  
The Stability

Human blood is often used as an ex vivo model to mimic the environment encountered by pathogens inside the host. A significant variety of experimental conditions has been reported. However, optimization strategies are often not described. This study aimed to evaluate key parameters that are expected to influence Staphylococcus epidermidis gene expression when using human blood ex vivo models. Our data confirmed that blood antimicrobial activity was dependent on initial bacterial concentration. Furthermore, blood degradation over time resulted in lower antimicrobial activity, with a 2% loss of leukocytes viability correlating with a 5-fold loss of antimicrobial activity against S. epidermidis. We further demonstrated that the volume of human blood could be reduced to as little as 0.18 mL without affecting the stability of gene expression of the tested genes. Overall, the data described herein highlight experimental parameters that should be considered when using a human blood ex vivo model for S. epidermidis gene expression analysis.

scholarly journals Analysis of resorbable mesh implants in short-term human muscular fascia cultures: a pilot study

Hernia ◽  
2020 ◽  
Vol 24 (6) ◽  
pp. 1283-1291
Author(s):  
V. Trapani ◽  
G. Bagni ◽  
M. Piccoli ◽  
I. Roli ◽  
F. Di Patti ◽  
...  
Keyword(s):  
Hernia Repair ◽  
Ex Vivo ◽  
Tissue Remodeling ◽  
Vital Staining ◽  
Culture Method ◽  
Type I ◽  
Ex Vivo Model ◽  
Tissue Samples ◽  
Color Deconvolution ◽  
Resorbable Implants

Abstract Purpose Alteration in fascial tissue collagen composition represents a key factor in hernia etiology and recurrence. Both resorbable and non-resorbable meshes for hernia repair are currently used in the surgical setting. However, no study has investigated so far the role of different implant materials on collagen deposition and tissue remodeling in human fascia. The aim of the present study was to develop a novel ex vivo model of human soft tissue repair mesh implant, and to test its suitability to investigate the effects of different materials on tissue remodeling and collagen composition. Methods Resorbable poly-4-hydroxybutyrate and non-resorbable polypropylene mesh implants were embedded in human abdominal fascia samples, mimicking common surgical procedures. Calcein-AM/Propidium Iodide vital staining was used to assess tissue vitality. Tissue morphology was evaluated using Mallory trichrome and hematoxylin and eosin staining. Collagen type I and III expression was determined through immunostaining semi-quantification by color deconvolution. All analyses were performed after 54 days of culture. Results The established ex vivo model showed good viability at 54 days of culture, confirming both culture method feasibility and implants biocompatibility. Both mesh implants induced a disorganization of collagen fibers pattern. A statistically significantly higher collagen I/III ratio was detected in fascial tissue samples cultured with resorbable implants compared to either non-resorbable implants or meshes-free controls. Conclusion We developed a novel ex vivo model and provided evidence that resorbable polyhydroxybutyrate meshes display better biomechanical properties suitable for proper restoration in surgical hernia repair.

1849: Systematic Evaluation of 21μm Thulium Laser Device for Treatment of Benign Prostatic Enlargement in an Ex-VIVO Model

2007 ◽  
Vol 177 (4S) ◽  
pp. 614-614 ◽  
Author(s):  
Gunnar Wendt-Nordahl ◽  
Stefanie Huckele ◽  
Patrick Honeck ◽  
Peter Aiken ◽  
Thomas Knoll ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Systematic Evaluation ◽  
Thulium Laser ◽  
Laser Device ◽  
Benign Prostatic Enlargement ◽  
Ex Vivo Model ◽  
Prostatic Enlargement

Porcine small intestine, a good ex vivo model to investigate absorption and metabolism of natural products

2017 ◽  
Author(s):  
J Houriet ◽  
YE Arnold ◽  
C Petit ◽  
YN Kalia ◽  
JL Wolfender
Keyword(s):  
Natural Products ◽  
Small Intestine ◽  
Ex Vivo ◽  
Ex Vivo Model

Effects of Two Different Doses of Hirudin on APTT, Determined with Eight Different Reagents

1995 ◽  
Vol 73 (02) ◽  
pp. 219-222 ◽  
Author(s):  
Manuel Monreal ◽  
Luis Monreal ◽  
Rafael Ruiz de Gopegui ◽  
Yvonne Espada ◽  
Ana Maria Angles ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Anticoagulant Activity ◽  
Subcutaneous Administration ◽  
In Vitro Study ◽  
Ex Vivo Model ◽  
Suitable Candidate ◽  
Significant Prolongation ◽  
High Doses ◽  
Different Doses

SummaryThe APTT has been considered the most suitable candidate to monitor the anticoagulant activity of hirudin. However, its use is hampered by problems of standardization, which make the results heavily dependent on the responsiveness of the reagent used. Our aim was to investigate if this different responsiveness of different reagents when added in vitro is to be confirmed in an ex vivo study.Two different doses of r-hirudin (CGP 39393), 0.3 mg/kg and 1 mg/kg, were administered subcutaneously to 20 New Zealand male rabbits, and the differences in prolongation of APTT 2 and 12 h later were compared, using 8 widely used commercial reagents. All groups exhibited a significant prolongation of APTT 2 h after sc administration of hirudin, both at low and high doses. But this prolongation persisted 12 h later only when the PTTa reagent (Boehringer Mannheim) was used. In general, hirudin prolonged the APTT most with the silica- based reagents.In a further study, we compared the same APTT reagents in an in vitro study in which normal pooled plasma was mixed with increasing amount of hirudin. We failed to confirm a higher sensitivity for silica- containing reagents. Thus, we conclude that subcutaneous administration of hirudin prolongs the APTT most with the silica-based reagents, but this effect is exclusive for the ex vivo model.

EMR+: Vorstellung einer neuen endoskopischen Resektionsmethode im ex-vivo Model

2019 ◽  
Author(s):  
RF Knoop ◽  
E Wedi ◽  
V Ellenrieder ◽  
A Neesse ◽  
S Kunsch
Keyword(s):  
Ex Vivo ◽  
Ex Vivo Model
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