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Clinical Workflows Supported by Patient Care Device Data
Published in John R. Zaleski, Clinical Surveillance, 2020
A relationship exists between PaCO2 and CBF specifically in the PaCO2 range from 30 through 80 mmHg [120]. Reductions in PaCO2 result in vasoconstriction in cerebral vessels, reducing CBF and ICP. Yet, excessive reductions in PaCO2 can result in brain ischemia. Nominal ranges of PaCO2 of 35–45 mmHg, per weaning protocols, are designed to balance the competing effects leading to increases in ICP and ischemia. A factor that can impact CBF is blood viscosity primarily related to hematocrit. Hematocrit is measured and reported through comprehensive metabolic panels. Reduction in core body temperature also improves CBF tolerance [122]. Anesthetics and certain IV drugs can affect CBF through vasodilation, as well [38].
Chemical Exchange Saturation Transfer and Amide Proton Transfer Imaging
Published in Shoogo Ueno, Bioimaging, 2020
where Kw is the ion product of water at a given temperature. Therefore, under assumptions of constant amide proton concentration and water content, it is possible to obtain a pH-weighted image. Using a kbase value measured in an animal experiment with 31 P MRS, Zhou et al. [3] further demonstrated the feasibility of pH quantification of focal brain ischemia in a rat model. Sun et al. [65] demonstrated the value of APT imaging in identifying ischemic “penumbra,” the hypoperfused region that is still viable but at risk of infarction. In a rat ischemia model, they showed that a pH-weighted image at the hyperacute stage can predict the extent of final infarction more accurately than diffusion or perfusion-weighted imaging. This information may allow the optimal treatment strategy for patients with hyperacute ischemic stroke to be chosen. Nevertheless, to date, the clinical translation of APT-based pH-weighted imaging has not progressed, which is in part due to small signal intensity changes. Figure 5.11 shows a pH-weighted image of a patient with hyperacute infarction.
Vitis vinifera Extracts Against Free Radicals
Published in Cristobal N. Aguilar, Suresh C. Ameta, A. K. Haghi, Green Chemistry and Biodiversity, 2019
Katarína Valachová, Elsayed E. Hafez, Milan Nagy, Ladislav Šoltés
Pomegranate (Punica granatum L.) fruit is well-known for its nutritional and sensory properties. It grows in most tropical and subtropical countries and belongs to the Lythraceae family. Edible parts of this fruit are fresh seeds containing around 80% of juice and 20% of seed. The fruit is rich in minerals, pigments, galloylglucose, ellagic acid, alkaloids, glycosides, resins, volatile oils, gums, and tannins especially anthocyanins (glucosides of delphinidin and cyanidin), which have chemopreventive, antimutagenic, antibacterial, antihypertensive, antiatherogenic, and anti-oxidative properties. The fruit is also effective in reduction in liver injury (Bhandary et al., 2012; Rummun et al., 2013; Barman et al., 2014; Zhao et al., 2016). Pomegranate can be used in treatment and prevention of cardiovascular diseases, diabetes, dental conditions, and protection from ultraviolet radiation. Moreover, it is beneficial in infant brain ischemia, Alzheimer’s disease, male infertility, arthritis, and obesity (Kumar et al., 2012; Zhao et al., 2016).
Parecoxib exhibits anti-inflammatory and neuroprotective effects in a rat model of transient global cerebral ischemia
Published in Journal of Toxicology and Environmental Health, Part A, 2020
Shaoxing Liu, Yue’e Dai, Chen Zhou, Tao Zhu
Cerebral ischemia reperfusion injury may produce inflammatory responses, excitotoxicity, free radicals, and acute Ca2+ overload, all of these events leading to BBB dysfunction and apoptosis (Amantea et al. 2016; Mo, Sun, and Liu 2020; Wu et al. 2018, 2019). Inflammatory responses and oxidative stress are crucial in the progression of cerebral ischemia reperfusion injury (Song et al. 2019; Wu et al. 2019). Persistent inflammatory responses may initiate ischemic neuron cell apoptosis and neurological deficit in cerebral ischemia reperfusion injury. Inflammation, BBB dysfunction, and apoptosis promote the development of ischemic reperfusion injury. Anti-inflammatory treatment is one of the strategies for cerebral ischemia. It is well established that Chinese herbal medicinal plants possess constituents that are effective in cerebral ischemia reperfusion injury (Song et al. 2019; Wu et al. 2018, 2019). In addition, several investigators demonstrated that COX-2 inhibitors exhibited neuroprotective effects, improving neurological functional outcome in the brain ischemia, hemorrhage, Parkinson’s and Alzheimer’s disease, and traumatic brain injury (Dembo, Park, and Kharasch 2005; Yagami, Koma, and Yamamoto 2016).
Optimizing fast first pass complete reperfusion in acute ischemic stroke – the BADDASS approach (BAlloon guiDe with large bore Distal Access catheter with dual aspiration with Stent-retriever as Standard approach)
Published in Expert Review of Medical Devices, 2019
J. M. Ospel, O. Volny, M. Jayaraman, R. McTaggart, M. Goyal
Once the DAC is placed at the proximal end of the stent-retriever, the clot is corked/held captive, and we are ready to remove the stent-retriever/clot/DAC complex as one unit. At this point, we inflate the balloon of the guide catheter to create a state of flow arrest. We then apply aspiration (either manually with a syringe or automated aspiration using a pump) to both the DAC and the BGC (Figure 8). This combined aspiration technique has been shown to decrease procedure times and, more importantly, improves patient outcome [36]. We start aspiration at the time of the clot retrieval. While some authors postulate that continuous aspiration before clot retrieval improves flow control, it also potentially worsens brain ischemia by decreasing collateral inflow in the ischemic parenchyma through flow reversal in collateral vessels. The precise timing of turning on aspiration is yet to be optimized with there being pro's and con's of various timings. However, as a general rule, the total time of aspiration should be kept to a minimum.
MRI-guided endovascular intervention: current methods and future potential
Published in Expert Review of Medical Devices, 2022
Bridget F. Kilbride, Kazim H. Narsinh, Caroline D. Jordan, Kerstin Mueller, Teri Moore, Alastair J. Martin, Mark W. Wilson, Steven W. Hetts
Many endovascular interventional radiology applications have been tested in vivo in animal models, given the lack of clinically approved devices. Notable preclinical applications that could benefit from using MRI to quantitatively measure success are stroke embolectomy and tumor embolization. Recently, one group demonstrated a proof-of-concept performing a carotid embolectomy under MRI guidance in a swine stroke model [147]. This approach could be particularly valuable in acute ischemic stroke where intervention could be streamlined into one interventional suite, reducing treatment delays and allowing for intra-procedural evaluation of brain parenchyma viability, such that reperfusion therapy could be directed to living tissue and not at infarcted tissue [148]. Lillaney et al. demonstrated the ability to embolize renal arteries in a swine embolization model, additionally evaluating perfusion and flow pre- and post-procedure as imaging biomarkers [114]. Similar studies have been executed demonstrating renal artery embolization and hepatic artery drug infusion [149,150]. This approach could be particularly valuable in tumor embolization where new MR imaging techniques are being applied to evaluate tumor perfusion reduction during chemoembolization and have been shown to predict transplant-free survival [146]. Other interventional radiology applications that have been tested in animal models include endovascular stenting of aortic aneurysms [151,152], stenting of descending thoracic dissections [153], angioplasty and stenting of arteries including carotid, renal and iliac arteries [82,154–156], inferior vena cava filter placement [157], and creation of porto-systemic shunts [158,159]. Preclinical interventional cardiology applications include coronary artery septum placement [160,161], pulmonary artery stenting [162], balloon angioplasty of aortic co-arctation [163], aortic valve placement [164] and septum occlusion [165,166]. Oncology applications have established small and large animal models for stem cell delivery to the CNS [167] as well as optimization of OBBBO with other intra-arterial therapies [140,168–170]. Finally, researchers have found an intersection between molecular MRI and endovascular interventions with chemical exchange saturation transfer (CEST) MR contrast agents. Preclinical models to better assess OBBBO perfusion territory [171] and function as ‘label-free’ theranostics following brain ischemia [172] have been identified in this field of research in addition to an expanding portfolio of MR contrast agents on the horizon [173].