scholarly journals Effect of cannulation site on emboli travel during cardiac surgery

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Mira Puthettu ◽  
Stijn Vandenberghe ◽  
Stefanos Demertzis
Keyword(s):  
Cardiac Surgery ◽  
In Vitro Study ◽  
Blood Stream ◽  
Air Bubbles ◽  
Arterial Tree ◽  
Air Bubble ◽  
Cannulation Site ◽  
The Brain

Abstract Background During cardiac surgery, micro-air emboli regularly enter the blood stream and can cause cognitive impairment or stroke. It is not clearly understood whether the most threatening air emboli are generated by the heart-lung machine (HLM) or by the blood-air contact when opening the heart. We performed an in vitro study to assess, for the two sources, air emboli distribution in the arterial tree, especially in the brain region, during cardiac surgery with different cannulation sites. Methods A model of the arterial tree was 3D printed and included in a hydraulic circuit, divided such that flow going to the brain was separated from the rest of the circuit. Air micro-emboli were injected either in the HLM (“ECC Bubbles”) or in the mock left ventricle (“Heart Bubbles”) to simulate the two sources. Emboli distribution was measured with an ultrasonic bubble counter. Five repetitions were performed for each combination of injection site and cannulation site, where air bubble counts and volumes were recorded. Air bubbles were separated in three categories based on size. Results For both injection sites, it was possible to identify statistically significant differences between cannulation sites. For ECC Bubbles, axillary cannulation led to a higher amount of air bubbles in the brain with medium-sized bubbles. For Heart Bubbles, aortic cannulation showed a significantly bigger embolic load in the brain with large bubbles. Conclusions These preliminary in vitro findings showed that air embolic load in the brain may be dependent on the cannulation site, which deserves further in vivo exploration.

Effects of Short Duration Overpressure on Astrocytes: An In Vitro Study

2007 ◽  
Author(s):  
Lai Yee Leung ◽  
Pamela J. VandeVord ◽  
Warren Hardy ◽  
Roche De Guzman ◽  
King H. Yang ◽  
...  
Keyword(s):  
Short Duration ◽  
Neuronal Degeneration ◽  
In Vitro Study ◽  
Underlying Mechanism ◽  
Blast Waves ◽  
Body Armor ◽  
The Brain ◽  
Physiological Systems

Blast wave overpressure from detonations can injure physiological systems ‘silently.’ Experimental and clinical studies have revealed the damaging effects of shock waves on different physiological systems, such as ears, lungs and gastrointestinal tracts [1, 2]. Despite the improved helmet and body armor, many veterans returning from wars suffered from neurological disorders that are being diagnosed as mild traumatic brain injury. Warden (2006) reported that most of these veterans were exposed to blast [3]. In vivo study illustrated neuronal degeneration in the brain after exposure to blast waves [4]. As with many neuronal diseases, blast-induced neuronal injury may be related to microglia and astrocyte activation. However, the underlying mechanism is not clearly understood. This study was aimed at investigating the effects of short duration overpressure on astrocytes, in terms of cell proliferation and mRNA expression of several apoptotic genes and glial fibrillary acidic protein (GFAP).

scholarly journals Nanoparticles Based on Quaternary Ammonium Chitosan-methyl-β-cyclodextrin Conjugate for the Neuropeptide Dalargin Delivery to the Central Nervous System: An In Vitro Study

Pharmaceutics ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 5
Author(s):  
Chiara Migone ◽  
Letizia Mattii ◽  
Martina Giannasi ◽  
Stefania Moscato ◽  
Andrea Cesari ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Quaternary Ammonium ◽  
Oral Absorption ◽  
In Vitro Study ◽  
Brain Barrier ◽  
Mucosal Barrier ◽  
Blood Brain ◽  
The Brain

Peptide oral administration is a hard goal to reach, especially if the brain is the target site. The purpose of the present study was to set up a vehicle apt to promote oral absorption of the neuropeptide dalargin (DAL), allowing it to cross the intestinal mucosal barrier, resist enzymatic degradation, and transport drugs to the brain after crossing the blood–brain barrier. Therefore, a chitosan quaternary ammonium derivative was synthesized and conjugated with methyl-β-cyclodextrin to prepare DAL-medicated nanoparticles (DAL-NP). DAL-NP particle size was 227.7 nm, zeta potential +8.60 mV, encapsulation efficiency 89%. DAL-NP protected DAL from degradation by chymotrypsin or pancreatin and tripled DAL degradation time compared to non-encapsulated DAL. Use of DAL-NP was safe for either Caco-2 or bEnd.3 cells, with the latter selected as a blood–brain barrier model. DAL-NP could also cross either the Caco-2 or bEnd.3 monolayer by the transepithelial route. The results suggest a potential DAL-NP ability to transport to the brain a DAL dose fraction administered orally, although in vivo experiments will be needed to confirm the present data obtained in vitro.

In vitro and in vivo Evaluation of the Radiochemical Compound Based on 99mTechnetium Labelled DARPin 9_29 for Molecular Visualization of Malignancies Overexpressing Her2/neu

2020 ◽  
Vol 65 (1) ◽  
pp. 37-41
Author(s):  
O. Bragina ◽  
A. Vorobyeva ◽  
V. Tolmachev ◽  
A. Orlova ◽  
V. Chernov ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Radiochemical Yield ◽  
Blood Stream ◽  
The Body ◽  
Diagnostic Methods ◽  
In Vivo Studies ◽  
In Vivo Evaluation ◽  
High Accumulation

Purpose: Evaluation of a radiopharmaceutical based on 99mTc-labeled targeted molecules DARPin9_29 for radionuclide diagnostics of malignancies with Her2/neu overexpression. Material and methods: The DARPin9_29 sequence was amplified from the plasmid pET-DARP-6HIS for the DARPin9_29-His6 gene expression in E. coli cells. The eluent of 99mTcO4– (400–500 μl, 4 GBq) was added to the kit and incubated at a temperature of 100 °C for 20 minutes. After incubation, 40 μl of tricarbonyl technetium was added to 168 μg of DARPin9_29 in 100 μl of PBS (sodium phosphate buffer), followed by incubation at 40 °C for 60 minutes. The radiochemical yield and purity were determined by thin layer radiochromatography, the purification was performed using NAP-5 cleansing columns (GE Healthcare). Cell lines with different levels of Her2/neu expression were used: SKOV-3> BT474 >> DU-145 for the determination of the radiopharmaceutical specificity. Her2/neu expressing cell line SKOV-3 was used for in vitro study. The study was conducted 6 hours after the administration of the drug. Results: The radiochemical yield was 72 ± 8 %, the radiochemical purity after purification was 98.7 ± 1.0 %. The stability in PBS (phosphate buffered saline) solution after 1 hour was 99.8 ± 0.2; after 3 hours – 98.2 ± 0.1. In vitro studies showed that the accumulation of explored compound was directly proportional to the level of Her2/neu expression in cells, while blocking the receptors with an excess of unlabeled protein showed a significant reduction in binding in the group of cells. Data on biodistribution and SPECT/CT in the body of the animal BALB/c nu/nu demonstrated rapid removal of the compound from the blood stream and high accumulation in the liver, kidney and bladder 6 hours after the introduction of the radiopharmaceutical. Conclusion: The studies demonstrated high radiochemical yields and purity, as well as stability of the studied compound. The results of in vitro and in vivo analysis showed the specificity and affinity of the radiopharmaceutical to the Her2/neu receptor on the surface of tumor cells. The high accumulation of the drug in the liver and kidneys, detected in in vivo studies, is probably due to the lipophilicity of the 99mTc(CO)3-histidine tag and indicates the limitation of its further clinical use in assessing the condition of the above organs, which will require additional diagnostic methods, as well as possible modification chemical structure.

The Action of Glutamic Acid in Hypoglycaemic Coma

1949 ◽  
Vol 95 (401) ◽  
pp. 930-944 ◽  
Author(s):  
H. Weil-Malherbe
Keyword(s):  
Glutamic Acid ◽  
Brain Tissue ◽  
Brain Slices ◽  
Direct Consequence ◽  
Shock Therapy ◽  
Blood Stream ◽  
Nervous Function ◽  
The Brain

The loss of consciousness in hypoglycaemia is generally regarded as a direct consequence of the fact that the brain cells are being increasingly deprived of glucose, their principal fuel. The prompt relief of symptoms by glucose administration led to a number of investigations on the effect of other substrates known to sustain the respiration of surviving brain slices in vitro. Amongst these are various mono- and disaccharides, and such acids as lactic, pyruvic, succinic or glutamic acid which may be formed from glucose in the course of its metabolism. It appeared, however, that, in contrast to their in vitro action, most of these substances, including glutamic acid, were unable to relieve the symptoms of hypoglycaemia in eviscerated or hepatectomized animals (Bollmann and Mann, 1931; Maddock, Hawkins and Holmes, 1939). Similarly, lactic and pyruvic acids were found to have no effect on the oxygen consumption of the brain or the comatose state of hypoglycaemic patients undergoing insulin shock therapy (Wortis and Goldfarb, 1940; Goldfarb and Wort is, 1941). It has been shown for several substrates, including glutamic acid, that their rate of diffusion from the blood stream into brain tissue was markedly slower than that of glucose, and that therefore the concentration necessary for the maintenance of nervous function was not reached (Klein, Hurwitz and Olsen, 1946; Klein and Olsen, 1947). In harmony with this are the observations of Fried berg and Greenberg (1947), and of Waelsch, Schwerin and Bessman (1949) that intravenously injected glutamic acid is not taken up by brain tissue. The differences between the in vitro and in vivo results seemed to be adequately explained by these experiments.

Involvement of cytochrome P450 2D in the formation of serotonin in the brain: in vivo and in vitro study

2016 ◽  
Vol 26 ◽  
pp. S262
Author(s):  
A. Haduch ◽  
E. Bromek ◽  
J. Wójcikowski ◽  
K. Gołembiowska ◽  
W.A. Daniel
Keyword(s):  
Cytochrome P450 ◽  
In Vitro Study ◽  
Vitro Study ◽  
The Brain

Effect of pH and inhibitors on beta-amyloid fibril assembly

1996 ◽  
Vol 54 ◽  
pp. 752-753
Author(s):  
Beverly E. Maleeff ◽  
Timothy K. Hart ◽  
Stephen J. Wood ◽  
Ronald Wetzel
Keyword(s):  
Amyloid Fibril ◽  
Peptide Fragment ◽  
Hydrophobic Peptides ◽  
Amyloid Fibril Formation ◽  
Effects Of Ph ◽  
Severity Of The Disease ◽  
Kinetics Of ◽  
The Brain

Alzheimer's disease is characterized post-mortem in part by abnormal extracellular neuritic plaques found in brain tissue. There appears to be a correlation between the severity of Alzheimer's dementia in vivo and the number of plaques found in particular areas of the brain. These plaques are known to be the deposition sites of fibrils of the protein β-amyloid. It is thought that if the assembly of these plaques could be inhibited, the severity of the disease would be decreased. The peptide fragment Aβ, a precursor of the p-amyloid protein, has a 40 amino acid sequence, and has been shown to be toxic to neuronal cells in culture after an aging process of several days. This toxicity corresponds to the kinetics of in vitro amyloid fibril formation. In this study, we report the biochemical and ultrastructural effects of pH and the inhibitory agent hexadecyl-N-methylpiperidinium (HMP) bromide, one of a class of ionic micellar detergents known to be capable of solubilizing hydrophobic peptides, on the in vitro assembly of the peptide fragment Aβ.

Effects of TSH and calcitriol on bone metabolism: in vivo and in vitro study

2014 ◽  
Author(s):  
Ivo Dumic-Cule ◽  
Dunja Rogic ◽  
Damir Jezek ◽  
Lovorka Grgurevic ◽  
Slobodan Vukicevic
Keyword(s):  
Bone Metabolism ◽  
In Vitro Study ◽  
Vitro Study
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