Intraoperative study of the functional perforasome - an experimental model

Medicine and Pharmacy Reports ◽

10.15386/mpr-1896 ◽

2021 ◽

Author(s):

Maria-Eliza Nedu ◽

Alexandru Dan Valentin Georgescu

Keyword(s):

Methylene Blue ◽

Experimental Model ◽

Direct Injection ◽

Fluorescent Dye ◽

Medial Branch ◽

Perforator Flaps ◽

Epigastric Artery ◽

Blue Solution ◽

Minimal Concentration

Background and aims. The aim of this study is to find the most suitable protocol based on an animal experimental model, through the use of a fluorescent dye, determining also its minimal concentration needed to stain the skin after arterial injection, in order to be evidence the functional perforasome by visual examination. Methods. Methylene blue solution was used in order to determine the territory vascularized by one perforator on fresh cadavers in many studies which introduced, as a final result, the concept of perforasome. One of the most frequent complications of perforator flaps is partial flap necrosis which could be avoided by correctly assessing pre-operatively the functional perforasome surface. Two groups of seven rats were used in order to establish a proper surgical protocol to evaluate the functional perforasome in vivo by injecting the dye. Also, the minimal concentration for methylene blue was experimentally determined. Results. The direct injection into the femoral artery of the proper concentration of dye, 1mM for methylene blue and the clamping of all the branches except the medial branch of the superficial epigastric artery is a reliable model to study the functional perforasome. Conclusions. Our study demonstrates that the intraoperative assessment with fluorescent dye of the functional perforasome by intra-arterial injection of methylene blue is an easy, affordable and very efficient method to reduce the number of partial necrosis of the perforator flaps.

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Fluorescent, Prussian Blue-Based Biocompatible Nanoparticle System for Multimodal Imaging Contrast

Nanomaterials ◽

10.3390/nano10091732 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1732

Author(s):

László Forgách ◽

Nikolett Hegedűs ◽

Ildikó Horváth ◽

Bálint Kiss ◽

Noémi Kovács ◽

...

Keyword(s):

Methylene Blue ◽

Prussian Blue ◽

Fluorescent Dyes ◽

Light Emission ◽

Fluorescent Dye ◽

Fluorescent Imaging ◽

Fluorescent Light ◽

Eosin Y ◽

Biodistribution Studies

(1) Background. The main goal of this work was to develop a fluorescent dye-labelling technique for our previously described nanosized platform, citrate-coated Prussian blue (PB) nanoparticles (PBNPs). In addition, characteristics and stability of the PB nanoparticles labelled with fluorescent dyes were determined. (2) Methods. We adsorbed the fluorescent dyes Eosin Y and Rhodamine B and methylene blue (MB) to PB-nanoparticle systems. The physicochemical properties of these fluorescent dye-labeled PBNPs (iron(II);iron(III);octadecacyanide) were determined using atomic force microscopy, dynamic light scattering, zeta potential measurements, scanning- and transmission electron microscopy, X-ray diffraction, and Fourier-transformation infrared spectroscopy. A methylene-blue (MB) labelled, polyethylene-glycol stabilized PBNP platform was selected for further assessment of in vivo distribution and fluorescent imaging after intravenous administration in mice. (3) Results. The MB-labelled particles emitted a strong fluorescent signal at 662 nm. We found that the fluorescent light emission and steric stabilization made this PBNP-MB particle platform applicable for in vivo optical imaging. (4) Conclusion. We successfully produced a fluorescent and stable, Prussian blue-based nanosystem. The particles can be used as a platform for imaging contrast enhancement. In vivo stability and biodistribution studies revealed new aspects of the use of PBNPs.

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Ultrastructure of melanocyte-keratinocyte interactions and pigment transfer in vitro

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100084120 ◽

1978 ◽

Vol 36 (2) ◽

pp. 650-651

Author(s):

Raul I. Garcia ◽

Evelyn A. Flynn ◽

George Szabo

Keyword(s):

Direct Injection ◽

Skin Pigmentation ◽

Freeze Fracture ◽

Pigment Granule ◽

Time Lapse ◽

Ultrastructural Level ◽

Lanthanum Tracer ◽

A Cell

Skin pigmentation in mammals involves the interaction of epidermal melanocytes and keratinocytes in the structural and functional unit known as the Epidermal Melanin Unit. Melanocytes(M) synthesize melanin within specialized membrane-bound organelles, the melanosome or pigment granule. These are subsequently transferred by way of M dendrites to keratinocytes(K) by a mechanism still to be clearly defined. Three different, though not necessarily mutually exclusive, mechanisms of melanosome transfer have been proposed: cytophagocytosis by K of M dendrite tips containing melanosomes, direct injection of melanosomes into the K cytoplasm through a cell-to-cell pore or communicating channel formed by localized fusion of M and K cell membranes, release of melanosomes into the extracellular space(ECS) by exocytosis followed by K uptake using conventional phagocytosis. Variability in methods of transfer has been noted both in vivo and in vitro and there is evidence in support of each transfer mechanism. We Have previously studied M-K interactions in vitro using time-lapse cinemicrography and in vivo at the ultrastructural level using lanthanum tracer and freeze-fracture.

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Hepato- and Nephroprotective Effects of the Polyphenol Concentrate From Cabernet Sauvignon Grape Varieties Cultivated in Kazakhstan in the Experimental Model Of CCL4-Induced Toxicity

INTERNATIONAL JOURNAL OF TOXICOLOGICAL AND PHARMACOLOGICAL RESEARCH ◽

10.25258/ijtpr.v9i03.9068 ◽

2017 ◽

Vol 9 (03) ◽

Author(s):

Nurgozhin T. ◽

Sergazy S. H. ◽

Adilgozhina G. ◽

Gulyayev A. ◽

Shulgau Z. ◽

...

Keyword(s):

Carbon Tetrachloride ◽

Experimental Model ◽

Lethal Dose ◽

Radical Scavenging ◽

Cabernet Sauvignon ◽

Intragastric Administration ◽

Liver And Kidney ◽

Antioxidant Stress

Objective:This study investigates the hepatoprotective effect and the antioxidant role of polyphenol concentrate in the experimental model of carbon tetrachloride (CCl4) induced toxicity. Methods: Antioxidant activity of Cabernet Sauvignon grape polyphenol were evaluated by radical scavenging of 1,1-diphenyl-2-picryl hydrazyl radical (DPPH), 2,2’-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS.+). In addition, the effects of polyphenol concentrate on the survival of Wistar rats in the toxicity model, was also investigated. The polyphenol concentrate was administered for 5 five days prior to injection of carbon tetrachloride in a sub-lethal dose of 300 mg/kg of animal body weight in order to perform histological examinations of the liver and kidney, and detect the levels of AST, ALT and bilirubin. Results: Administration of polyphenol concentrate increased animal survival in the experimental model. Moreover, the intragastric administration of polyphenol concentrate prior to the initiation of the experimental model of toxicity, which was caused by a sub-lethal CCl4 dose, reduced morphological injuries in the liver and kidney, decreased the AST and ALT levels of the blood serum. Discussion and conclusion: Our data demonstrate that polyphenol concentrate possesses an antioxidant potential both in vitro and in vivo by reducing antioxidant stress that was caused by CCl4 administration into rats.

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Faculty Opinions recommendation of Agents blocking the nuclear factor-kappaB pathway are effective inhibitors of endometriosis in an in vivo experimental model.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1097205.553211 ◽

2007 ◽

Author(s):

Ali Akoum

Keyword(s):

Experimental Model ◽

Nuclear Factor Kappab ◽

Nuclear Factor

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Chimeric Mouse With Humanized Liver Is an Appropriate Animal Model to Investigate Mode of Action for Porphyria-Mediated Hepatocytotoxicity

Toxicologic Pathology ◽

10.1177/01926233211027474 ◽

2021 ◽

pp. 019262332110274

Author(s):

Ayumi Eguchi ◽

Satoki Fukunaga ◽

Keiko Ogata ◽

Masahiko Kushida ◽

Hiroyuki Asano ◽

...

Keyword(s):

Experimental Model ◽

Mode Of Action ◽

Aminolevulinic Acid ◽

Protoporphyrin Ix ◽

Human Hepatocytes ◽

Chimeric Mouse ◽

Hepatocellular Injury ◽

Hepatocyte Necrosis ◽

Key Events

Porphyrinogenic compounds are known to induce porphyria-mediated hepatocellular injury and subsequent regenerative proliferation in rodents, ultimately leading to hepatocellular tumor induction. However, an appropriate in vivo experimental model to evaluate an effect of porphyrinogenic compounds on human liver has not been fully established. Recently, the chimeric mouse with humanized liver (PXB mice) became widely used as a humanized model in which human hepatocytes are transplanted. In the present study, we examined the utility of PXB mice as an in vivo experimental model to evaluate the key events of the porphyria-mediated cytotoxicity mode of action (MOA) in humans. The treatment of PXB mice with 5-aminolevulinic acid, a representative porphyrinogenic compound, for 28 days caused protoporphyrin IX accumulation, followed by hepatocyte necrosis, increased mitosis, and an increase in replicative DNA synthesis in human hepatocytes, indicative of cellular injury and regenerative proliferation, similar to findings in patients with porphyria or experimental porphyria models and corresponding to the key events of the MOA for porphyria-mediated hepatocellular carcinogenesis. We conclude that the PXB mouse is a useful model to evaluate the key events of the porphyria-mediated cytotoxicity MOA in humans and suggest the utility of PXB mice for clarifying the human relevancy of findings in mice.

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