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Pidcoke HF, Delacruz W, Herzig MC, Schaffer BS, Leazer ST, Fedyk CG, Montogomery RK, Prat NJ, Parida BK, Aden JK, Scherer MR, Reddick RL, Shade RE, Cap AP. Perfluorocarbons cause thrombocytopenia, changes in RBC morphology and death in a baboon model of systemic inflammation. PLoS One 2022; 17:e0279694. [PMID: 36584001 PMCID: PMC9803179 DOI: 10.1371/journal.pone.0279694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 12/13/2022] [Indexed: 12/31/2022] Open
Abstract
A perfluorocarbon (PFC) investigated for treatment of traumatic brain injury (TBI) delivers oxygen to support brain function, but causes transient thrombocytopenia. TBI can cause acute inflammation with resulting thrombocytopenia; an interaction between the PFC effects and TBI inflammation might exacerbate thrombocytopenia. Therefore, PFC effects on platelet (PLT) function and hemostasis in a lipopolysaccharide (LPS) model of inflammation in the baboon were studied. Animals were randomized to receive saline ±LPS, and ± one of two doses of PFC. PLT count, transmission electron microscopy, and microparticle populations were quantified at baseline (BL) and at 2, 24, 48, 72, and 96 hours; hemostatic parameters for aggregometry and for blood clotting were measured at baseline (BL) and days 3 and 4. Injection of vehicle and LPS caused thrombocytopenia within hours; PFCs caused delayed thrombocytopenia beginning 48 hours post-infusion. LPS+PFC produced a more prolonged PLT decline and decreased clot strength. LPS+PFC increased ADP-stimulated aggregation, but PFC alone did not. Microparticle abundance was greatest in the LPS+PFC groups. LPS+PFC caused diffuse microvascular hemorrhage and death in 2 of 5 baboons in the low dose LPS-PFC group and 2 of 2 in the high dose LPS-PFC group. Necropsy and histology suggested death was caused by shock associated with hemorrhage in multiple organs. Abnormal morphology of platelets and red blood cells were notable for PFC inclusions. In summary, PFC infusion caused clinically significant thrombocytopenia and exacerbated LPS-induced platelet activation. The interaction between these effects resulted in decreased hemostatic capacity, diffuse bleeding, shock and death.
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Affiliation(s)
- Heather F. Pidcoke
- Blood and Shock Resuscitation, U.S. Army Institute of Surgical Research, Fort Sam Houston, TX, United States of America
| | - Wilfred Delacruz
- Hematology-Oncology Service, San Antonio Military Medical Center, Fort Sam Houston, TX, United States of America
| | - Maryanne C. Herzig
- Blood and Shock Resuscitation, U.S. Army Institute of Surgical Research, Fort Sam Houston, TX, United States of America
| | - Beverly S. Schaffer
- Blood and Shock Resuscitation, U.S. Army Institute of Surgical Research, Fort Sam Houston, TX, United States of America
| | - Sahar T. Leazer
- Blood and Shock Resuscitation, U.S. Army Institute of Surgical Research, Fort Sam Houston, TX, United States of America
| | - Chriselda G. Fedyk
- Blood and Shock Resuscitation, U.S. Army Institute of Surgical Research, Fort Sam Houston, TX, United States of America
| | - Robbie K. Montogomery
- Blood and Shock Resuscitation, U.S. Army Institute of Surgical Research, Fort Sam Houston, TX, United States of America
| | - Nicolas J. Prat
- Blood and Shock Resuscitation, U.S. Army Institute of Surgical Research, Fort Sam Houston, TX, United States of America
| | - Bijaya K. Parida
- Blood and Shock Resuscitation, U.S. Army Institute of Surgical Research, Fort Sam Houston, TX, United States of America
| | - James K. Aden
- Blood and Shock Resuscitation, U.S. Army Institute of Surgical Research, Fort Sam Houston, TX, United States of America
| | - Michael R. Scherer
- Blood and Shock Resuscitation, U.S. Army Institute of Surgical Research, Fort Sam Houston, TX, United States of America
| | - Robert L. Reddick
- Department of Pathology and Laboratory Medicine, University of Texas, Health Science Center, San Antonio, TX, United States of America
| | - Robert E. Shade
- Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX, United States of America
| | - Andrew P. Cap
- Blood and Shock Resuscitation, U.S. Army Institute of Surgical Research, Fort Sam Houston, TX, United States of America
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Mini-review: Perfluorocarbons, Oxygen Transport, and Microcirculation in Low Flow States: in Vivo and in Vitro Studies. Shock 2020; 52:19-27. [PMID: 28930919 DOI: 10.1097/shk.0000000000000994] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The in vivo study of microvascular oxygen transport requires accurate and challenging measurements of several mass transfer parameters. Although recommended, blood flow and oxygenation are typically not measured in many studies where treatments for ischemia are tested. Therefore, the aim of this communication is to briefly review cardinal aspects of oxygen transport, and the effects of perfluorocarbon (PFC) treatment on blood flow and oxygenation based mostly on studies performed in our laboratory. As physiologically relevant events in oxygen transport take place at the microvascular level, we implemented the phosphorescence quenching technique coupled with noninvasive intravital videomicroscopy for quantitative evaluation of these events in vivo. Rodent experimental models and various approaches have been used to induce ischemia, including hemorrhage, micro- and macroembolism, and microvessel occlusion. Measurements show decrease in microvascular blood flow as well as intravascular and tissue oxygen partial pressure (PO2) after these procedures. To minimize or reverse the effects of ischemia and hypoxia, artificial oxygen carriers such as different PFCs were tested. Well-defined endpoints such as blood flow and tissue PO2 were measured because they have significant effect on tissue survival and outcome. In several cases, enhancement of flow and oxygenation could be demonstrated. Similar results were found in vitro: PFC emulsion mixed with blood (from healthy donors and sickle cell disease patients) enhanced oxygen transport. In summary, PFCs may provide beneficial effects in these models by mechanisms at the microvascular level including facilitated diffusion and bubble reabsorption leading to improved blood flow and oxygenation.
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Padma AM, Truong M, Jar-Allah T, Song MJ, Oltean M, Brännström M, Hellström M. The development of an extended normothermic ex vivo reperfusion model of the sheep uterus to evaluate organ quality after cold ischemia in relation to uterus transplantation. Acta Obstet Gynecol Scand 2019; 98:1127-1138. [PMID: 30932168 DOI: 10.1111/aogs.13617] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 03/01/2019] [Accepted: 03/27/2019] [Indexed: 12/17/2022]
Abstract
INTRODUCTION Uterus transplantation has recently proved that infertility in women with uterine factor infertility can be cured. It is still an experimental procedure with numerous critical details remaining to be established, including tolerance to warm and cold ischemic insults. In preparation for human uterus transplantation trials, most teams use the sheep as a model system for research and team training, since the vasculature and the uterus is of similar size as in the human. We, therefore, aimed to develop an ex vivo sheep uterus reperfusion platform that mimics the reperfusion situation so that initial assessments and comparisons can be performed without the need for costly and labor-intensive in vivo transplantation experiments. MATERIAL AND METHODS Isolated sheep uteri were perfused with the preservation solution IGL-1 and were then exposed to cold ischemia for either 4 (n = 6) or 48 hours (n = 7). Uteri were then reperfused for 48 hours under normothermic conditions with an oxygenated recirculating perfusate containing growth factors and synthetic oxygen carriers. Histological and biochemical analysis of the perfusate was conducted to assess reperfusion injury. RESULTS Quantification of cell density indicated no significant edema in the myometrium or in the endometrium of uteri exposed to 4 hours cold ischemia and then a normothermic ex vivo reperfusion for 48 hours. Only the outer serosa layer and the inner columnar luminal epithelial cells were affected by the reperfusion. However, a much faster and severe reperfusion damage of all uterine layers were evident during the reperfusion experiment following 48 hours of cold ischemia. This was indicated by major accumulation of extracellular fluid, presence of apoptotic-labeled glandular epithelial layer and vascular endothelium. A significant accumulation of lactate was measured in the perfusate with a subsequent decrease in pH. CONCLUSIONS We developed a novel ex vivo sheep uterus model for prolonged perfusion. This model proved to be able to distinguish reperfusion injury-related differences associated to organ preservation. The experimental setup is a platform that can be used to conduct further studies on uterine ischemia- and reperfusion injury that may lead to improved human uterus transplantation protocols.
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Affiliation(s)
- Arvind M Padma
- Laboratory for Transplantation and Regenerative Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Department of Obstetrics and Gynecology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - MyLan Truong
- Laboratory for Transplantation and Regenerative Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Department of Obstetrics and Gynecology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Tagrid Jar-Allah
- Laboratory for Transplantation and Regenerative Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Department of Obstetrics and Gynecology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Min J Song
- Laboratory for Transplantation and Regenerative Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Department of Obstetrics and Gynecology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Daejeon St. Mary's Hospital, The Catholic University of Korea, Daejeon, South Korea
| | - Mihai Oltean
- Laboratory for Transplantation and Regenerative Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Department of Surgery, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Mats Brännström
- Laboratory for Transplantation and Regenerative Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Department of Obstetrics and Gynecology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Stockholm IVF-EUGIN, Stockholm, Sweden
| | - Mats Hellström
- Laboratory for Transplantation and Regenerative Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Department of Obstetrics and Gynecology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
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Abutarboush R, Mullah SH, Saha BK, Haque A, Walker PB, Aligbe C, Pappas G, Tran Ho LTV, Arnaud FG, Auker CR, McCarron RM, Scultetus AH, Moon-Massat P. Brain oxygenation with a non-vasoactive perfluorocarbon emulsion in a rat model of traumatic brain injury. Microcirculation 2018; 25:e12441. [DOI: 10.1111/micc.12441] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 01/12/2018] [Indexed: 12/17/2022]
Affiliation(s)
- Rania Abutarboush
- NeuroTrauma Department; Naval Medical Research Center; Silver Spring MD USA
| | - Saad H. Mullah
- NeuroTrauma Department; Naval Medical Research Center; Silver Spring MD USA
| | - Biswajit K. Saha
- NeuroTrauma Department; Naval Medical Research Center; Silver Spring MD USA
| | - Ashraful Haque
- NeuroTrauma Department; Naval Medical Research Center; Silver Spring MD USA
| | - Peter B. Walker
- NeuroTrauma Department; Naval Medical Research Center; Silver Spring MD USA
| | - Chioma Aligbe
- Department of Surgery; Uniformed Services University of the Health Sciences; Bethesda MD USA
| | - Georgina Pappas
- Department of Surgery; Uniformed Services University of the Health Sciences; Bethesda MD USA
| | | | - Francoise G. Arnaud
- NeuroTrauma Department; Naval Medical Research Center; Silver Spring MD USA
- Department of Surgery; Uniformed Services University of the Health Sciences; Bethesda MD USA
| | - Charles R. Auker
- NeuroTrauma Department; Naval Medical Research Center; Silver Spring MD USA
| | - Richard M. McCarron
- NeuroTrauma Department; Naval Medical Research Center; Silver Spring MD USA
- Department of Surgery; Uniformed Services University of the Health Sciences; Bethesda MD USA
| | - Anke H. Scultetus
- NeuroTrauma Department; Naval Medical Research Center; Silver Spring MD USA
- Department of Surgery; Uniformed Services University of the Health Sciences; Bethesda MD USA
| | - Paula Moon-Massat
- NeuroTrauma Department; Naval Medical Research Center; Silver Spring MD USA
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Kawaguchi AT, Yamano M, Haida M, Ohba H, Kakiuchi T, Tsukada H. Effect of Oxygen Affinity of Liposome-Encapsulated Hemoglobin on Cerebral Ischemia and Reperfusion as Detected by Positron Emission Tomography in Nonhuman Primates. Artif Organs 2017; 41:336-345. [DOI: 10.1111/aor.12905] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2016] [Accepted: 11/22/2016] [Indexed: 12/21/2022]
Affiliation(s)
| | | | - Munetaka Haida
- Tokai University Junior College of Nursing and Medical Technologies; Hiratsuka
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Tegeler C, Sherman D. Analytic Review: Ischemic Cerebrovascular Disease: Diagnosis and Management. J Intensive Care Med 2016. [DOI: 10.1177/088506668600100404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Ischemic stroke is the most common cause of neurologic morbidity and mortality. The proper management of a stroke patient is dictated by the underlying pathophysiology. An ischemic stroke may occur as a result of restricted flow or thrombosis from atherosclerosis, artery-to-artery embolization, cardiac-to-brain embolization, or disorders of coagulation, to mention a few of the most common causes. Determining the relevant cause of stroke is made more difficult by the coexistence of many possible factors such as hypertension, atherosclerosis, and cardiac disease. Nevertheless, judgments are based on the clinical presentation, computed tomographic scans, cerebral angiograms, and results of echocardiography and electrocardiographic monitoring. Therapy of the ischemic stroke patient is aimed primarily at preserving areas of potentially recoverable ischemic brain. This is accomplished by correcting or avoiding circumstances that can promote further impairment of ischemic brain. These include proper management of blood pressure, cardiac function, oxygenation, and fluid balance. The role of anticoagulation, hemodilution therapy, and other proposed forms of therapy is often unclear.
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Affiliation(s)
- Charles Tegeler
- Department of Medicine, Division of Neurology, University of Texas Health Science Center, San Antonio, Texas
| | - David Sherman
- Department of Medicine, Division of Neurology, University of Texas Health Science Center, San Antonio, Texas
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Wang PF, Zhou Y, Fang H, Lin S, Wang YC, Liu Y, Xia J, Eslick GD, Yang QW. Treatment of acute cerebral ischemia using animal models: a meta-analysis. Transl Neurosci 2015; 6:47-58. [PMID: 28123790 PMCID: PMC4936615 DOI: 10.1515/tnsci-2015-0006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 12/11/2014] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND There are numerous potential treatments assessed for acute cerebral ischemia using animal models. This study aimed to assess the effect of these treatments in terms of infarct size and neurobehavioral change. This meta-analysis was conducted to determine if any of these treatments provide a superior benefit so that they might be used on humans. METHODS A systematic search was conducted using several electronic databases for controlled animal studies using only nonsurgical interventions for acute cerebral ischemia. A random-effects model was used. RESULTS After an extensive literature search, 145 studies were included in the analysis. These studies included 1408 treated animals and 1362 control animals. Treatments that had the most significant effect on neurobehavioral scales included insulin, various antagonists, including N-methyl-D-aspartate (NMDA) receptor antagonist ACEA1021, calmodulin antagonist DY-9760e, and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist YM872, and antiviral agents. Treatments providing the greatest effect on infarct size included statins, sphingosine-1-phosphate agonist (fingolimod), alcohol, angiotensin, and leukotrienes. Treatments offering the greatest reduction in brain water content included various agonists, including sphingosine-1-phosphate agonist fingolimod, statins, and peroxisome proliferator-activated receptor gamma (PPAR-γ). Treatment groups with more than one study all had high heterogeneity (I2 > 80%), however, using meta-regression we determined several sources of heterogeneity including sample size of the treatment and control groups, the occlusion time, but not the year when the study was conducted. CONCLUSIONS Some treatments stand out when compared to others for acute cerebral ischemia in animals. Greater replication of treatment studies is required before any treatments are selected for future human trials.
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Affiliation(s)
- Peng-Fei Wang
- Department of Neurology, Xinqiao Hospital, The Second Affiliated Hospital, The Third Military Medical University, Chongqing, China
| | - Yu Zhou
- Department of Neurology, Xinqiao Hospital, The Second Affiliated Hospital, The Third Military Medical University, Chongqing, China
| | - Huang Fang
- Department of Neurology, Xinqiao Hospital, The Second Affiliated Hospital, The Third Military Medical University, Chongqing, China
| | - Sen Lin
- Department of Development and Regeneration Key Laboratory of Sichuan Province, Department of Histoembryology and Neurobiology, Chengdu Medical College, Chengdu, China
| | - Yan-Chun Wang
- Department of Neurology, Xinqiao Hospital, The Second Affiliated Hospital, The Third Military Medical University, Chongqing, China
| | - Yong Liu
- Department of Neurology, Xinqiao Hospital, The Second Affiliated Hospital, The Third Military Medical University, Chongqing, China
| | - Jun Xia
- Systematic Review Solutions, China
| | - Guy D Eslick
- Department of Surgery, The University of Sydney, Nepean Hospital, Penrith, Australia
| | - Qing-Wu Yang
- Department of Neurology, Xinqiao Hospital, The Second Affiliated Hospital, The Third Military Medical University, Chongqing, China
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Schneider UC, Karutz T, Schilling L, Woitzik J. Administration of a second generation perfluorochemical in combination with hyperbaric oxygenation does not provide additional benefit in a model of permanent middle cerebral artery occlusion in rats. SPRINGERPLUS 2014; 3:32. [PMID: 25674426 PMCID: PMC4320177 DOI: 10.1186/2193-1801-3-32] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 01/03/2014] [Indexed: 01/24/2023]
Abstract
Objective Both, second generation perfluorochemicals (Oxycyte®) and hyperbaric oxygen (HBO) have been shown to reduce necrotic tissue volume if administered early after experimental cerebral ischemia. With the idea of exponentiation of oxygen delivery to ischemic tissue, this study was conducted to investigate the combined effect of both treatment modalities on the extent of ischemic brain damage. Methods Permanent focal cerebral ischemia was induced in rats by middle cerebral artery occlusion (MCAO). Animals were assigned randomly to one of the following treatment groups: Control (0.9% NaCl, 1 ml/100 g i.v.), Oxycyte® (1 ml/100 g i.v.), HBO (1 bar hyperbaric oxygenation for 1 h) and HBO + Oxycyte® (1 ml/100 g i.v. combined with 1 bar hyperbaric oxygenation for 1 h). Injection of NaCl or Oxycyte® was performed following MCAO. After injection, breathing was changed to 100% oxygen in Oxycyte®-, HBO- and HBO + Oxycyte®-groups. After eight hours the necrotic volume was calculated from serial coronal sections stained with silver-nitrate and corrected for the extent of swelling. Results Hemodynamic and metabolic parameters were not affected by infusion of Oxycyte®. Total necrosis volume was significantly reduced in HBO-treated animals (223 ± 70 mm3), when compared to control animals (335 ± 36 mm3). In animals after Oxycyte®-treatment alone (299 ± 33 mm3) or combined HBO + Oxycyte®-treatment (364 ± 50 mm3) did not show a significantly smaller necrosis volume compared to control animals (necrosis volumes are given as mean ± SD). Discussion These results suggest that combination of hyperbaric oxygenation and Oxycyte® administered immediately after onset of vascular occlusion does not provide an additional neuroprotective effect in the early phase of brain ischemia.
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Affiliation(s)
- Ulf C Schneider
- Department of Neurosurgery, Charité - Universitätsmedizin Berlin, Berlin, Germany ; Center for Stroke Research Berlin, Berlin, Germany
| | - Tobias Karutz
- Department of Neurosurgery, University Hospital Mannheim, Mannheim, Germany
| | - Lothar Schilling
- Department of Neurosurgery, University Hospital Mannheim, Mannheim, Germany
| | - Johannes Woitzik
- Department of Neurosurgery, Charité - Universitätsmedizin Berlin, Berlin, Germany ; Center for Stroke Research Berlin, Berlin, Germany ; Department of Neurosurgery, University Hospital Mannheim, Mannheim, Germany
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Woitzik J, Weinzierl N, Schilling L. Early administration of a second-generation perfluorochemical decreases ischemic brain damage in a model of permanent middle cerebral artery occlusion in the rat. Neurol Res 2013; 27:509-15. [PMID: 15978177 DOI: 10.1179/016164105x15677] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVES Perfluorochemicals (PFCs) may exert a neuroprotective function in the early phase of ischemia by improving the oxygen supply to the endangered tissue. We have, therefore, investigated the effect of Oxycyte, a second-generation perfluorocarbon solution, on the extent of early ischemic brain damage in a model of permanent focal cerebral ischemia. METHODS Eight hours of permanent focal cerebral ischemia was induced in isoflurane anesthetized male Sprague-Dawley rats by unilateral middle cerebral artery (MCA) thread occlusion under the control of laser Doppler flowmetry (LDF). Animals were assigned to one of the following treatment groups: nO2-NaCl and hO2-NaCl-NaCl (0.9%, 1 ml/100 g i.v.) and nO2-Oxycyte and hO2-Oxycyte-Oxycyte (1 ml/100 g i.v.). The injection of NaCl or Oxycyte was performed immediately after MCA occlusion. After injection, breathing was changed to pure oxygen in groups hO2-NaCl and hO2-Oxycyte while animals in groups nO2-NaCl and nO2-Oxycyte were allowed to breathe air. The necrotic volume was calculated from serial coronal sections stained with silver-nitrate. In addition, nitrotyrosine production was studied by immunohistochemistry. RESULTS Upon MCA occlusion, animals showed a reduction of cerebral blood flow of approximately 80% of the LDF signal in all groups. Hemodynamic and metabolic parameters were not affected by the infusion of Oxycyte. The total infarct volume was reduced in hO2-Oxycyte animals [group nO2-NaCl: 341+/-31 mm3 (mean+/-SD), group hO2-NaCl: 351+/-33 mm3, group nO2-Oxycyte: 354+/-24 mm3, and group hO2-Oxycyte: 300+/-29 mm3, p < 0.05 versus all other groups]. Moreover, hO2-Oxycyte animals showed lesser intensity of nitrotyrosine staining when compared with hO2-NaCl animals. DISCUSSION These results suggest that Oxycyte administered immediately after the onset of vascular occlusion may exert neuroprotective effects in the early phase of brain ischemia.
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Affiliation(s)
- Johannes Woitzik
- Department of Neurosurgery, University Hospital Mannheim, Mannheim, Germany.
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Kawaguchi AT, Kurita D, Furuya H, Yamano M, Ogata Y, Haida M. Liposome-encapsulated hemoglobin alleviates brain edema after permanent occlusion of the middle cerebral artery in rats. Artif Organs 2009; 33:153-8. [PMID: 19178460 DOI: 10.1111/j.1525-1594.2008.00700.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Liposome-encapsulated hemoglobin (LEH) was proven to be protective in cerebral ischemia/reperfusion injury. The present study evaluated LEH in a rat model of permanent middle cerebral artery (MCA) occlusion to clarify its effect during ischemia and reperfusion. Five minutes after thread occlusion of the MCA, rats were infused with 10 mL/kg of LEH (LEH, n = 13), and compared with normal controls (n = 11). Additional animals received the same MCA occlusion with no treatment (CT, n = 11), saline (saline, n = 10), empty liposome solution (EL, n = 13), or washed red blood cells (RBC, n = 7). Severity of brain edema was determined 24 h later by signal strength in T2-weighted magnetic resonance imaging of the cortex, striatum, hippocampus, and pyriform lobe. The results showed that brain edema/infarction observed in any vehicle-infused control was significantly more severe than in LEH-treated rats. There was a tendency toward aggravated edema in rats receiving ELs. LEH infusion at a dose of 10 mL/kg significantly reduced edema formation as compared to other treatments in a wide area of the brain 24 h after permanent occlusion of the MCA. Low oncotic pressure of EL and LEH solution (vehicle solution) appeared to cause nonsignificant aggravation of edema and reduced protective effects of LEH.
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Zhou Z, Sun D, Levasseur JE, Merenda A, Hamm RJ, Zhu J, Spiess BD, Bullock MR. Perfluorocarbon emulsions improve cognitive recovery after lateral fluid percussion brain injury in rats. Neurosurgery 2009; 63:799-806; discussion 806-7. [PMID: 18981892 DOI: 10.1227/01.neu.0000325493.51900.53] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE Perfluorocarbon emulsions have been shown to improve outcomes in stroke models. This study examined the effect of Oxycyte, a third-generation perfluorocarbon emulsion (04RD33; Synthetic Blood International, Inc., Costa Mesa, CA) treatment on cognitive recovery and mitochondrial oxygen consumption after a moderate lateral fluid percussion injury (LFPI). METHODS Adult male Sprague-Dawley rats (Harlan Bioproducts for Science, Indianapolis, IN) were allocated to 4 groups: 1) LFPI treated with a lower dose of Oxycyte (4.5 mL/kg); 2) LFPI with a higher dose of Oxycyte (9.0 mL/kg); 3) LFPI with saline infusion; and 4) sham animals treated with saline. Fifteen minutes after receiving moderate LFPI or sham surgery, animals were infused intravenously with Oxycyte or saline within 30 minutes while breathing 100% O2. Animals breathed 100% O2 continuously for a total of 4 hours after injury. At 11 to 15 days after LFPI, animals were assessed for cognitive deficits using the Morris water maze test. They were sacrificed at Day 15 after injury for histology to assess hippocampal neuronal cell loss. In a parallel study, mitochondrial oxygen consumption values were measured by the Cartesian diver microrespirometer method. RESULTS We found that injured animals treated with a lower or higher dose of Oxycyte had significant improvement in cognitive function when compared with injured saline-control animals (P < 0.05). Moreover, injured animals that received either dose of Oxycyte had significantly less neuronal cell loss in the hippocampal CA3 region compared with saline-treated animals (P < 0.05). Furthermore, a lower dose of Oxycyte significantly improved mitochondrial oxygen consumption levels (P < 0.05). CONCLUSION The current study demonstrates that Oxycyte can improve cognitive recovery and reduce CA3 neuronal cell loss after traumatic brain injury in rats.
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Affiliation(s)
- Zhengwen Zhou
- Department of Neurosurgery, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia, USA
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Yang ZJ, Price CD, Bosco G, Tucci M, El-Badri NS, Mangar D, Camporesi EM. The effect of isovolemic hemodilution with oxycyte, a perfluorocarbon emulsion, on cerebral blood flow in rats. PLoS One 2008; 3:e2010. [PMID: 18431491 PMCID: PMC2291566 DOI: 10.1371/journal.pone.0002010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2008] [Accepted: 03/04/2008] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Cerebral blood flow (CBF) is auto-regulated to meet the brain's metabolic requirements. Oxycyte is a perfluorocarbon emulsion that acts as a highly effective oxygen carrier compared to blood. The aim of this study is to determine the effects of Oxycyte on regional CBF (rCBF), by evaluating the effects of stepwise isovolemic hemodilution with Oxycyte on CBF. METHODOLOGY Male rats were intubated and ventilated with 100% O(2) under isoflurane anesthesia. The regional (striatum) CBF (rCBF) was measured with a laser doppler flowmeter (LDF). Stepwise isovolemic hemodilution was performed by withdrawing 4ml of blood and substituting the same volume of 5% albumin or 2 ml Oxycyte plus 2 ml albumin at 20-minute intervals until the hematocrit (Hct) values reached 5%. PRINCIPAL FINDINGS In the albumin-treated group, rCBF progressively increased to approximately twice its baseline level (208+/-30%) when Hct levels were less than 10%. In the Oxycyte-treated group on the other hand, rCBF increased by significantly smaller increments, and this group's mean rCBF was only slightly higher than baseline (118+/-18%) when Hct levels were less than 10%. Similarly, in the albumin-treated group, rCBF started to increase when hemodilution with albumin caused the CaO(2) to decrease below 17.5 ml/dl. Thereafter, the increase in rCBF was accompanied by a nearly proportional decrease in the CaO(2) level. In the Oxycyte-treated group, the increase in rCBF was significantly smaller than in the albumin-treated group when the CaO(2) level dropped below 10 ml/dl (142+/-20% vs. 186+/-26%), and rCBF returned to almost baseline levels (106+/-15) when the CaO(2) level was below 7 ml/dl. CONCLUSIONS/SIGNIFICANCE Hemodilution with Oxycyte was accompanied with higher CaO(2) and PO(2) than control group treated with albumin alone. This effect may be partially responsible for maintaining relatively constant CBF and not allowing the elevated blood flow that was observed with albumin.
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Affiliation(s)
- Zhong-jin Yang
- Department of Anesthesiology, SUNY Upstate Medical University, Syracuse, New York, United States of America
| | - Chrystal D. Price
- Department of Anesthesiology, University of South Florida, Tampa, Florida
| | - Gerardo Bosco
- Department of Physiology, University of Chieti, Chieti, Italy
| | - Micheal Tucci
- Department of Anesthesiology, SUNY Upstate Medical University, Syracuse, New York, United States of America
| | - Nagwa S. El-Badri
- Department of Anesthesiology, University of South Florida, Tampa, Florida
| | - Devanand Mangar
- Department of Anesthesiology, University of South Florida, Tampa, Florida
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13
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Daugherty WP, Levasseur JE, Sun D, Spiess BD, Bullock MR. Perfluorocarbon Emulsion Improves Cerebral Oxygenation and Mitochondrial Function after Fluid Percussion Brain Injury in Rats. Neurosurgery 2004; 54:1223-30; discussion 1230. [PMID: 15113478 DOI: 10.1227/01.neu.0000119238.68938.5d] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2003] [Accepted: 01/14/2004] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE Cerebral ischemia is a common secondary sequela of traumatic brain injury (TBI). Experimental models of stroke have demonstrated reductions in ischemia after perfluorocarbon (PFC) administration; however, there are no published reports of PFC efficacy after TBI. The current study analyzed the effect of the PFC emulsion Oxygent (AF0144; Alliance Pharmaceutical Corp., San Diego, CA) on cerebral oxygenation, mitochondrial redox potential, and free radical formation after lateral fluid percussion injury. METHODS After fluid percussion injury, five 2.25 ml/kg doses of PFC or saline were administered to rats breathing 100% O(2), and oxygen tension was recorded. In a second experiment, a single bolus (11.25 ml/kg) of PFC or saline was given after injury, and redox potential and free radical formation were measured at 1 or 4 hours with Alamar blue dye and dihydrorhodamine 123, respectively. RESULTS Cerebral oxygen tension was significantly increased in both injured and sham animals treated with 11.25 ml/kg of PFC as compared with saline (P < 0.05). Likewise, PFC significantly increased mitochondrial redox potential as compared with saline at 4 hours after injury (P < 0.01). Mitochondrial peroxynitrite and peroxide production also increased with the administration of PFC (P < 0.05). CONCLUSION The current study demonstrates that a PFC emulsion can significantly increase cerebral oxygenation after TBI and enhance mitochondrial function at 4 hours after injury as compared with saline. This study demonstrates a new therapeutic potential for PFC to enhance cerebral oxygenation and aerobic metabolism after TBI. However, the increased free radical formation with high-dose PFCs suggests the need for further studies combining PFCs with free radical scavengers.
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Affiliation(s)
- Wilson P Daugherty
- Departments of Neurosurgery and Physiology, Medical College of Virginia, Virginia Commonwealth University, Richmond, Virginia 23298, USA
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14
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Yang YR, Wang RY, Wang PSG, Yu SM. Treadmill training effects on neurological outcome after middle cerebral artery occlusion in rats. Can J Neurol Sci 2003; 30:252-8. [PMID: 12945951 DOI: 10.1017/s0317167100002687] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Treadmill training is used for promoting rhythmical vigorous walking and for task-related training in patients with stroke. The neurological impact of treadmill training has not been established. The present investigation is aimed at (1) examining neurological changes over a four-week period after middle cerebral artery occlusion (MCAO) in rats and (2) assessing the impact of one-week, two-week and four-week treadmill training in MCAO rats. METHODS Male Sprague-Dawley rats were subjected to 60-minute right MCAO. All rats were randomly assigned to one of seven groups. Infarct volume and neurological score were measured. RESULTS Rats sacrificed 24 hours post MCAO had the largest infarct volumes (171.4 +/- 14.4 mm3) and the highest neurological score (median: 2, range: 1-3). We noted that without treadmill training, infarct sizes and neurological score diminished with time. Treadmill training for at least one week further reduced infarct volume and significantly improved neurologic function in MCAO rats. CONCLUSION Treadmill training after focal cerebral ischemia significantly improves neurological outcome in MCAO rats. Treadmill training may be beneficial for ischemic brain recovery.
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Affiliation(s)
- Yea-Ru Yang
- Faculty and Institute of Physical Therapy, National Yang-Ming University, Shih-Pai, Taipei, Taiwan
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15
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Riess JG. Oxygen carriers ("blood substitutes")--raison d'etre, chemistry, and some physiology. Chem Rev 2001; 101:2797-920. [PMID: 11749396 DOI: 10.1021/cr970143c] [Citation(s) in RCA: 544] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- J G Riess
- MRI Institute, University of California at San Diego, San Diego, CA 92103, USA.
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16
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Padnick LB, Linsenmeier RA, Goldstick TK. Perfluorocarbon emulsion improves oxygenation of the cat primary visual cortex. J Appl Physiol (1985) 1999; 86:1497-504. [PMID: 10233110 DOI: 10.1152/jappl.1999.86.5.1497] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Tissue PO2 was measured in the primary visual cortex of anesthetized, artificially ventilated, normovolemic cats to evaluate the effect of small doses [1 g perfluorocarbon (PFC)/kg] of a PFC emulsion (1 g PFC/1.1 ml emulsion; Alliance Pharmaceutical, San Diego, CA) on brain oxygenation. The change in tissue PO2 (DeltaPO2), resulting from briefly changing the respiratory gas from room air to 100% oxygen, was measured before and after intravenous infusion of the emulsion. Before emulsion, DeltaPO2 was 51.1 +/- 45.6 Torr (n = 8 cats). Increases in DeltaPO2 of 34.0 +/- 26.1 (SD) % (n = 8) and 16. 3 +/- 8.4% (n = 6) were observed after the first and second emulsion infusions, respectively. The further increase in DeltaPO2 after the third dose (7.9 +/- 10.5%; n = 7) was not statistically significant. The observed increases in tissue oxygenation as a result of the PFC infusions appear to be the result of enhanced oxygen transport to the tissue.
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Affiliation(s)
- L B Padnick
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208-3107, USA
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Abstract
Perfluorocarbons are now being used as oxygen carriers in clinical settings. Because these chemicals may have a role as a blood substitute, in organ preservation, and in the management of respiratory failure, we have reviewed some of the research leading to these applications.
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Affiliation(s)
- M C Clark
- Department of Mechanical Engineering, University of Memphis, Tennessee, USA
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19
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Doppenberg EM, Watson JC, Bullock R, Gerber MJ, Zauner A, Abraham DJ. The rationale for, and effects of oxygen delivery enhancement to ischemic brain in a feline model of human stroke. Ann N Y Acad Sci 1997; 825:241-57. [PMID: 9369991 DOI: 10.1111/j.1749-6632.1997.tb48435.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Reduced brain tissue oxygenation is frequently seen in severe head injury and after subarachnoid hemorrhage, and this is considered a major cause of secondary ischemic brain injury. In fact, in a previous study, we found a tight correlation between low brain tissue oxygen tension and poor outcome. Therefore, we tested the hypothesis that an allosteric modifier of hemoglobin, which improves oxygen transport to tissue, could reduce the size of an acute infarct in a feline model of human stroke. This compound produces a shift in the hemoglobin dissociation curve to the right and therefore facilitates the unloading of oxygen during low oxygen tension. Seventeen adult cats were studied. Ischemic stroke was induced through a transorbital, permanent, middle cerebral artery occlusion. Seven animals received saline, and 10 received the allosteric Hb modifier RSR-13. Three different endpoints were used to determine the effect of the allosteric modifier. Delta p50 values were measured in the arterial blood; the intra-infarct oxygen tension was measured, and finally, the volume of the infarct was assessed using TTC staining. Mean delta p50 changes varied from 10.4 +/- 9.2 mmHg up to 15.0 +/- 6.8 mmHg. Mean intra-infarct oxygen tension was 27 +/- 6 mmHg for the control group and 33 +/- 7 mmHg for the drug-treated animals. The mean infarct size (measured as percentage of hemisphere volume) in the control group was 32 +/- 9% and for the RSR-13 animals 22 +/- 10% (p < 0.05). A definitive trend towards improvement in brain oxygen tension was seen, such that animals pretreated with RSR-13 showed a higher infarct oxygen tension. Infarct size was significantly reduced in the drug group. Therefore, RSR-13 is potentially beneficial in the treatment of brain ischemia. Since human studies with this compound are already completed, and other compounds which increase oxygen delivery, such as perfluorocarbons, are already being evaluated, it is likely that oxygen delivery enhancement will rapidly become the first 'neuroprotective' modality, employed in patients with severe brain injury, stroke and subarachnoid hemorrhage.
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Affiliation(s)
- E M Doppenberg
- Department of Neurosurgery, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0631, USA.
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20
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Doppenberg EM, Bullock R. Clinical neuro-protection trials in severe traumatic brain injury: lessons from previous studies. J Neurotrauma 1997; 14:71-80. [PMID: 9069438 DOI: 10.1089/neu.1997.14.71] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Major advances have been made in understanding the pathophysiological events after severe human traumatic brain injury, and consequently, many compounds have been tested in clinical trials. Thus far, no Phase III trials have been clearly successful, in human neurotrauma, although several Phase II studies have shown apparent benefit. This review is an attempt to identify factors that could be responsible for some of these failures. Recommendations are made that attempt to avoid these pitfalls in the future. Five criteria for future conduct of clinical trials are proposed. The usefulness of animal models for traumatic brain injury and their ability are discussed. Clearly, it is now becoming accepted that mechanism-driven trials, in which individual pathophysiological mechanisms are targeted, may be preferable in this heterogeneous patient population. The degree of brain penetration, the safety and tolerability of the compound, and end points used for outcome assessment are major influences upon the success of these trials. New approaches in developing, conducting, and analyzing these clinical trials should be considered in the future, if the costly failures of the past are not to be repeated, with the advent of newer "neuroprotective agents" and techniques.
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Affiliation(s)
- E M Doppenberg
- Division of Neurosurgery, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298, USA
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21
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Sakas DE, Whittaker KW, Crowell RM, Zervas NT. Perfluorocarbons: recent developments and implications for neurosurgery. J Neurosurg 1996; 85:248-54. [PMID: 8755753 DOI: 10.3171/jns.1996.85.2.0248] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Over the last 30 years, perfluorocarbons (PFCs) have been extensively investigated as oxygen carriers. Early studies indicated that these compounds could be used as blood substitutes or protective agents against ischemia. Adverse characteristics such as instability, short intravascular half-life, and uncertainties concerning possible toxicity precluded wide clinical application. However, advances in PFC technology have led to the development of improved second-generation oxygen carriers that incorporate well-tolerated emulsifiers (egg-yolk phospholipids). The authors review recent developments in this field and consider the potential role of PFCs in future neurosurgical practice. Diagnostic applications could include their use to assess cerebral blood flow, local oxygen tension, and brain metabolism or to achieve enhanced imaging and precise staging of inflammatory, neoplastic, or vascular disease processes by means of computerized tomography, ultrasonography, and magnetic resonance studies. Therapeutic applications could include cerebral protection, an adjunctive role in radiotherapy of malignant brain tumors, protection against air embolism, the preservation of organs for transplantation, and ventilatory support in head-injured patients with compromised lung function. In addition, PFCs have been used successfully as a tool in ophthalmic microsurgery and potentially they could fulfill a similar role in microneurosurgery.
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Affiliation(s)
- D E Sakas
- Neurosurgical Service, Massachusetts General Hospital, Harvard Medical School, Boston, USA
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Spiess BD, Cochran RP. Perfluorocarbon emulsions and cardiopulmonary bypass: a technique for the future. J Cardiothorac Vasc Anesth 1996; 10:83-89; quiz 89-90. [PMID: 8634391 DOI: 10.1016/s1053-0770(96)80182-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Artificial blood has been sought for a considerable period of time and two major lines of research have led to FDA testing of some possible compounds. The two major types of compounds are polymerized hemoglobin moieties and perfluorocarbon emulsions (PFC). Polymerized hemoglobin preparations have the ability to carry oxygen and release it in a manner similar to the oxyhemoglobin dissociation curve of whole blood. PFCs carry oxygen, nitrogen and carbon dioxide, as well as all other non-polar gases, by enhanced chemical solubility. Therefore, all dissolved gases are available for metabolic utilization and no sinusoidal release curve of oxygen is encountered. Early PFC emulsions had problems with toxicity of the emulsifier and were difficult to get into their emulsion for infusion. Furthermore they were very dilute in the active ingredient for gas transport. Today there are second generation PFCs becoming available that have a 40% concentration of the PFC and therefore the potential for gas transport is greatly increased. The PFC emulsions have a very small size, 0.1 microns, so the surface for gas exchange is massively increased as well as the potential increased for perfusion into areas of potentially sludged erythrocytes. Work with the PFCs has shown them now to be able to carry adequate oxygen to work as blood substitutes. They have shown protection from air embolism in a number of animal and end-organ models. What makes the PFCs unique is their ability to carry/absorb nitrogen and therefore protect from gas embolization. There are data in animal models showing significant cerebral protection in cardiopulmonary bypass models. The new PFCs should sometime in the not-too-distant future be tested in human bypass with assessments of neuropsychiatric dysfunction and stroke.
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Affiliation(s)
- B D Spiess
- Department of Anesthesiology, University of Washington, Seattle 98195, USA
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Guo J, White JA, Batjer HH. Intravenous perflubron emulsion administration improves the recovery of auditory evoked potentials after temporary brain stem ischemia in dogs. Neurosurgery 1995; 36:350-6; discussion 356-7. [PMID: 7731516 DOI: 10.1227/00006123-199502000-00015] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Oxygent, a second-generation perfluorocarbon (Perflubron) emulsion (Alliance Pharmaceutical Corporation, San Diego, CA) with superior oxygen delivery characteristics and greater stability than previous perfluorocarbon emulsions, was evaluated as a cerebroprotective agent in a dog model of partial brain stem ischemia. Six dogs were exposed to 20 minutes of isolated brain stem ischemia after receiving an intravenous bolus of Oxygent at a dose of 1.5 ml/kg. Brain stem auditory evoked potentials (BAEP) and regional cerebral blood flow were measured before and during the ischemia and for 5 hours after reperfusion. Changes in BAEP in this group were compared with those in four control dogs that experienced an identical ischemic period but that did not receive Oxygent. During the ischemic period, both control and Oxygent-treated animals experienced a dramatic decline in BAEP to under 10% of the baseline value. After reperfusion, the BAEP increased in both groups to between 50 and 70% of the baseline. In the Oxygent-treated group, the BAEP continued to recover to a final sustained level of over 80% of baseline. In contrast, the control animals suffered a drop in BAEP to 23% of baseline after the brief postischemic peak. The continued improvement in the BAEP in the Oxygent-treated group compared with the control groups suggests that Oxygent may be of some value as a protective agent to the brain stem during ischemia. This effect may be the result of improved oxygen delivery to the brain stem or may be related to other effects of Oxygent, such as reduction of reperfusion injury. Results suggest that Oxygent may be useful as a cerebroprotectant during cerebrovascular surgeries that require temporarily reducing blood flow to the brain stem.
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Affiliation(s)
- J Guo
- Department of Neurological Surgery, University of Texas Southwestern Medical Center, Dallas, USA
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24
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Intravenous Perflubron Emulsion Administration Improves the Recovery of Auditory Evoked Potentials after Temporary Brain Stem Ischemia in Dogs. Neurosurgery 1995. [DOI: 10.1097/00006123-199502000-00015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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25
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Millard RW. Oxygen solubility, rheology and hemodynamics of perfluorocarbon emulsion blood substitutes. ARTIFICIAL CELLS, BLOOD SUBSTITUTES, AND IMMOBILIZATION BIOTECHNOLOGY 1994; 22:235-44. [PMID: 8087245 DOI: 10.3109/10731199409117417] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Perfluorocarbon-based blood substitute emulsions have been under development for more than a quarter century. The first generation emulsions have provided confirmation that the physical principals of high gas solubility and low viscosity can effectively support organ and organism respiration and metabolism. Clinical trials led the US FDA in 1990 to be the first to approve a 20 w/v % perfluorocarbon emulsion for human use as coronary angioplasty adjuvant therapy. Hemodynamic responses to hemodilution with intravascular perfluorocarbon emulsions have varied with species and the mechanisms for adverse reactions are better understood now as second generation emulsions containing up to 100 w/v % perfluorocarbon are under development as blood substitutes, imaging agents, and for other therapeutic applications. This report describes the evolution of perfluorocarbon emulsions as blood substitutes by emphasizing oxygen solubility, rheology and hemodynamic aspects of the emulsions as they have been applied in experimental laboratory animal and human clinical settings.
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Affiliation(s)
- R W Millard
- College of Medicine, University of Cincinnati, Ohio 45267-0575
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Sakas DE, Crowell RM, Zervas NT. Effects of lecithin-emulsified perfluorochemical compounds in ischemic brain injury. ARTIFICIAL CELLS, BLOOD SUBSTITUTES, AND IMMOBILIZATION BIOTECHNOLOGY 1994; 22:83-9. [PMID: 8055099 DOI: 10.3109/10731199409117401] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A lecithin-emulsified "Pluronic F-68"-free perfluorochemical compound, named F-1,3-DMA, was tested as a new agent in the prevention of central nervous tissue ischemia. A permanent ischemia leading to cerebral infarction was induced after microsurgical exposure and occlusion of the internal carotid, anterior, and middle cerebral arteries in the rabbit. Following arterial occlusion, F-1,3-DMA was administered intravenously, in a solution rendered isotonic to plasma, over a 30 minute period. The F-1,3-DMA was well tolerated. Hemodynamic, cardiovascular and metabolic parameters were not affected by the infusion of F-1,3-DMA. Although PO2 remained virtually unchanged, animals treated with F-1,3-DMA (n = 9), had smaller infarct volume by 61 percent as compared to the control (n = 8) group (P < 0.04, Student's t-test). Histopathology did not reveal any F-1,3-DMA related damage in the non-infarcted brain. These results suggest that F-1,3-DMA has nervous tissue ischemia protective properties possibly because of microflow effects although O2 transport to "local" tissue may be enhanced as well. We believe that further research is necessary in order to make clinical trials of F-1,3-DMA possible.
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Affiliation(s)
- D E Sakas
- Massachusetts General Hospital, Department of Surgery, Harvard Medical School, Boston 02114
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McGovern KA, Schoeniger JS, Wehrle JP, Ng CE, Glickson JD. Gel-entrapment of perfluorocarbons: a fluorine-19 NMR spectroscopic method for monitoring oxygen concentration in cell perfusion systems. Magn Reson Med 1993; 29:196-204. [PMID: 8429783 DOI: 10.1002/mrm.1910290207] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Oxygenation is a major determinant of the physiological state of cultured cells. 19F NMR can be used to determine the oxygen concentration available to cells immobilized in a gel matrix by measuring the relaxation rate (1/T1) of perfluorocarbons (PFC) incorporated into the gel matrix. In calcium alginate gel beads without cells the relaxation rate (1/T1) of the trifluoromethyl group of perfluorotripropylamine (FTPA) varies linearly with oxygen concentration, with a slope of 1.26 +/- 0.15 x 10(-3) s-1 microM-1 and an intercept of 0.50 +/- 0.04 s-1. During perfusion with medium equilibrated with 95%/5% O2/CO2, changes in PFC T1s indicate that the average oxygen concentration was reduced from 894 +/- 102 microM in the absence of cells to 476 +/- 65 microM and 475 +/- 50 microM in the presence of 0.7 x 10(8) EMT6/Ro and RIF-1 murine tumor cells per milliliter of gel, respectively. The presence of 0.2 microliters of FTPA/ml of gel had no effect on the energy status of the cells as indicated by 31P NMR spectra. To calculate oxygen gradients within the beads from the average PFC T1 of the sample, a mathematical model was used assuming that oxygen is the limiting nutrient for cell metabolism and that the cellular oxygen consumption rate is independent of oxygen concentration. Data for EMT6/Ro cells were fit using experimentally determined perfusion parameters together with literature values for cell volume and oxygen consumption rate.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- K A McGovern
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287
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Mohan C, Gennaro M, Marini C, Ascer E. Reduction of the extent of ischemic skeletal muscle necrosis by perfusion with oxygenated perfluorocarbon. Am J Surg 1992; 164:194-8. [PMID: 1329572 DOI: 10.1016/s0002-9610(05)81069-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Oxygenated perfluorocarbon emulsion has been shown to preserve feline cerebral function after ischemia. The postulated protective effects of perfluorocarbons include improvement of blood rheology and prevention of neutrophil adherence by nonchemical inhibition of surface receptors. In this study, we used a well-described gracilis muscle model to investigate whether oxygenated perfluorocarbon can minimize skeletal muscle necrosis by mitigating the degree of leuko-sequestration. In eight adult mongrel dogs, both gracilis muscles were weighed and then subjected to 6 hours of normothermic ischemia followed by 48 hours of normothermic reperfusion. However, one randomly selected side (experimental side) was infused with oxygen (O2) Fluosol-DA 20% (4.4 +/- 0.2 mL O2/100 mL) intra-arterially at 12 mL/min for 40 minutes immediately after ischemia. Muscle biopsy specimens were obtained before ischemia and after 1 hour and 48 hours of reperfusion to estimate myeloperoxidase (MPO) activity, a marker of neutrophil infiltration. After 48 hours, both gracilis muscles were harvested and weighed in all animals. Muscle necrosis was measured by serial transections, nitroblue tetrazolium staining, and computerized planimetry. The transmuscular oxygen tension (pO2) of the gracilis muscle on the experimental side increased from 2 to 4 mm Hg during ischemia to 315 +/- 50 mm Hg during O2 Fluosol-DA 20% infusion. The percentage of muscle necrosis on the control side was 48.08% +/- 8.46%, compared with 27.62% +/- 6.96% on the experimental side (p less than 0.001). MPO activity was significantly higher at 48 hours of reperfusion compared with pre-ischemic and 1-hour reperfusion values (5.46 +/- 1.52 U/mg tissue protein versus 0.06 +/- 0.01 U/mg tissue protein and 0.16 +/- 0.06 U/mg tissue protein, respectively, in the control group; 1.78 +/- 0.60 U/mg tissue protein versus 0.16 +/- 0.08 U/mg tissue protein and 0.27 +/- 0.10 U/mg tissue protein, respectively, in the experimental group, p less than 0.05). However, MPO activity at 48 hours of reperfusion in the experimental group was significantly lower than in the control group (p less than 0.05). There was no difference in the percentage of weight gain between the control and the experimental groups (38.31% +/- 9.36% and 28.34% +/- 7.35%, respectively, p greater than 0.05). These data show that perfluorocarbons minimize the extent of skeletal muscle necrosis in this canine model. Based on our data on MPO activity, we believe t hat the protective effect of perfluorocarbons is in part due to th e decreased leuko-sequestration in the muscle during the the periods of ischemia and reperfusion.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- C Mohan
- Division of Vascular Surgery, Maimonides Medical Center, SUNY Health Science Center, Brooklyn
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Faithfull NS. Artificial oxygen carrying blood substitutes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1992; 317:55-72. [PMID: 1288172 DOI: 10.1007/978-1-4615-3428-0_6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Rockwell S, Kelley M, Irvin CG, Hughes CS, Yabuki H, Porter E, Fischer JJ. Preclinical evaluation of Oxygent as an adjunct to radiotherapy. BIOMATERIALS, ARTIFICIAL CELLS, AND IMMOBILIZATION BIOTECHNOLOGY : OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY FOR ARTIFICIAL CELLS AND IMMOBILIZATION BIOTECHNOLOGY 1992; 20:883-93. [PMID: 1391528 DOI: 10.3109/10731199209119735] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
These studies examine the potential value of a concentrated emulsion of perfluorooctylbromide (perflubron; Oxygent, Alliance Pharmaceutical Corp.) as an adjunct to radiotherapy. The effects of Oxygent on solid tumors were examined using EMT6 mammary tumors in BALB/c mice and BA1112 rhabdomyosarcomas in WAG/rij rats. Treatment with Oxygent plus O2, carbogen (95% O2/5% CO2), or hyperbaric oxygen (HBO) increased the effects of radiation on the tumors. Analyses of tumor cell survival curves and measurements of intratumor pO2 showed that this potentiation reflected an increase in the proportion of well-oxygenated tumor cells. Neither treatment of the animals with carbogen, O2, or HBO alone nor treatment of air-breathing rodents with Oxygent produced changes of similar magnitude. Treatment with a vehicle emulsion containing all the components of Oxygent except the perflubron did not alter tumor radiosensitivity, showing that tumor radiosensitization required the oxygen-transporting perfluorocarbon, and did not result from any biologic or physiologic effects of other components of the emulsion. These studies also examined the effects of Oxygent on the radiation responses of mouse skin and bone marrow. Oxygent selectively increased the radiation sensitivity of tumors relative to these normal tissues, thereby increasing the therapeutic ratio and producing therapeutic gain. Oxygent appears to warrant further testing as an adjunct to cancer therapy.
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Affiliation(s)
- S Rockwell
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06510-8040
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32
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Abstracts from the Second Japanese Neurotrauma Symposium Tokyo, Japan September 19,1990. J Neurotrauma 1991. [DOI: 10.1089/neu.1991.8.55] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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33
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34
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Preventive effect of Fluosol-DA for paraplegia encountered after surgical treatment of the thoracic aorta. J Thorac Cardiovasc Surg 1990. [DOI: 10.1016/s0022-5223(19)36941-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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35
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Lowe KC. Perfluorochemical oxygen carriers and ischaemic tissues. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1990; 277:257-66. [PMID: 2096631 DOI: 10.1007/978-1-4684-8181-5_31] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/27/2023]
Abstract
This paper has outlined the potential beneficial effects of emulsified PFCs for ischaemic tissue rescue. There are very strong indications that PFC emulsions will come to play an important part in the management of the ischaemic tissues. However, the immediate goal of future studies should be to assess the value of improved formulations in this context together with analysis of their mechanism(s) of action, both alone and in combination with other therapeutic agents.
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Affiliation(s)
- K C Lowe
- Dept. Zoology, University of Nottingham, University Park, UK
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36
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Aspey BS, Ehteshami S, Hurst CM, Pereira S, Harrison MJ. Effect of bezafibrate on the sequelae of acute experimental focal cerebral ischaemia. J Neurol Neurosurg Psychiatry 1989; 52:1432-4. [PMID: 2614443 PMCID: PMC1031607 DOI: 10.1136/jnnp.52.12.1432] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The possibility that the ability of bezafibrate to lower the oxygen affinity of haemoglobin might lead to an increased oxygen delivery to ischaemic cerebral tissue was explored in preliminary studies in two animal models. The combined morbidity and mortality of unilateral carotid ligation in the gerbil appeared to be reduced at two hours in bezafibrate treated animals. By four hours and thereafter the outcome was unaffected. Two hours after MCA occlusion bezafibrate-treated rats showed a significantly reduced rise in tissue lactate concentration (p less than 0.01) suggesting less anaerobic metabolism had occurred in the ischaemic tissue.
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Affiliation(s)
- B S Aspey
- Reta Lila Weston Institute of Neurological Studies, Middlesex Hospital, London, United Kingdom
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37
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Kern MJ, Deligonul U, Labovitz A. Influence of drug therapy on the ischemic response to acute coronary occlusion in man: supply-side economics. Am Heart J 1989; 118:361-80. [PMID: 2665464 DOI: 10.1016/0002-8703(89)90198-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- M J Kern
- Department of Internal Medicine, St. Louis University Hospital, MO 63110-0250
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38
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Lartigau E, Thomas C, Le Blanc M, Riess J, Long D, Long C, Malaise EP, Guichard M. New high O2 carrying perfluorochemical emulsions: toxicity, radiosensitivity of GM-CFC and development of metastases in mice. Int J Radiat Oncol Biol Phys 1989; 16:1153-6. [PMID: 2715062 DOI: 10.1016/0360-3016(89)90272-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The effects of two new concentrated perfluorochemical emulsions based on F-66E and PFOB, which carry significantly more oxygen than Fluosol-DA 20%, were tested on normal tissues (toxicity and radiation response) and on the development of metastases from Lewis Lung Carcinoma (3LL) in female C57 BL/6 mice. Twenty one days after injection of F-66E or PFOB emulsions (15 ml/kg body weight), the spleen and liver weights were significantly increased but had returned to normal after 2-3 months. Splenomegaly already observed in 3LL bearing mice was significantly increased by F-66E emulsion injection. The radiosensitivity of GM-CFC was not altered when unanesthetized GM-CFC was not altered when unanesthetized mice were pretreated with F-66E emulsions and/or carbogen 1 hr prior to and during irradiation. The rate of tumor take and the period before detection of tumors were not modified when an emulsion of F-66E was injected simultaneously or 10 days after 3LL cells. Mean survival of mice, and the number of metastases on lung surfaces were similar in F-66E injected mice and control mice.
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Affiliation(s)
- E Lartigau
- Laboratoire de Radiobiologie Cellulaire (Unité Inserm 247), Institut Gustave-Roussy, Villejuif, France
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39
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Abstract
EMT6 mouse mammary tumors transplanted into aging mice are less sensitive to radiation than are tumors growing in young adult animals. We hypothesized previously that this reflected a greater proportion of radiation resistant, hypoxic cells in the tumors of aging animals. The experiments reported here compare the radiation dose-response curves defining the survivals of tumor cells in aging mice and in young adult mice. Cell survival curves were assessed in normal air-breathing mice and in mice which had been asphyxiated with N2 to produce uniform hypoxia throughout the tumors. Analyses of these survival curves revealed that 41% of the viable malignant cells were severely hypoxic in tumors in aging mice, while only 19% of the tumor cells in young adult animals were radiobiologically hypoxic. This did not appear to reflect anemia in the old animals, as the hematocrits of young and aging tumor-bearing animals were similar. Treatment of aging animals with a perfluorochemical emulsion plus carbogen (95% O2/5% CO2) increased the radiation response of the tumors, apparently by improving tumor oxygenation and thereby decreasing the number of severely hypoxic, radiation resistant cells in the tumors.
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Affiliation(s)
- S Rockwell
- Yale University School of Medicine, Department of Therapeutic Radiology, New Haven, Connecticut 06510-8040
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Gelb AW, Steinberg GK, Lam AM, Manninen PH, Peerless SJ, Rassi-Neto A. The effects of a prophylactic bolus of lidocaine in focal cerebral ischaemia. Can J Anaesth 1988; 35:489-93. [PMID: 3168133 DOI: 10.1007/bf03026897] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
In order to determine the cerebral protective effects of an intravenous bolus of 5 mg.kg-1 of lidocaine, the left middle cerebral artery (MCA) was transorbitally occluded in 19 cats. Ten animals received the lidocaine bolus and nine a similar volume of saline immediately before MCA occlusion. Somatosensory evoked potentials (SEP) were recorded before and after the lidocaine bolus as well as continually after MCA occlusion. After six hours of vessel occlusion and without reperfusion, the animals were sacrificed and the brains fixed for histology. Prior to MCA occlusion, lidocaine caused a statistically significant (p less than 0.01) reduction in the amplitude of the major cortical component of the SEP (10 +/- 1.2 microV vs 6.0 +/- 1.3 microV). Latency was unchanged. In the lidocaine group, SEP's persisted in 40 per cent immediately following occlusion whereas they disappeared in all of the control animals (p less than 0.05). Gradual recovery occurred in both groups and there were no differences at the end of the experiment although the amplitudes tended to be greater in the lidocaine group. There were no statistically significant differences in the histological size or severity of the infarcts between the groups. Although infarct size was not reduced, transient sparing of the SEP suggests that further studies of lidocaine by continuous infusion in models of temporary focal cerebral ischaemia may be warranted.
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Affiliation(s)
- A W Gelb
- Department of Anaesthesia, University Hospital, University of Western Ontario, London
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41
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Eidelberg D, Johnson G, Tofts PS, Dobbin J, Crockard HA, Plummer D. 19F imaging of cerebral blood oxygenation in experimental middle cerebral artery occlusion: preliminary results. J Cereb Blood Flow Metab 1988; 8:276-81. [PMID: 3343299 DOI: 10.1038/jcbfm.1988.58] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Fluorine (19F) nuclear magnetic resonance may be used to image cerebral perfusion in cats receiving perfluorocarbon blood substitutes. 19F relaxation times in these blood substitutes are dependent on oxygen tension (PO2) and may be used to calculate and spatially map cerebrovascular PO2 values in vivo. We have applied this noninvasive method to experimental middle cerebral artery (MCA) occlusion. Following MCA occlusion a perfusion defect is evident in the sylvian region, followed by the appearance of collaterals. Signal from the ipsilateral rete mirabilis is increased. Calculated cortical vascular PO2 values indicate a relative reduction in oxygenation in the ischaemic hemisphere. PO2 maps show a perfused hypoxaemic zone adjacent to the perfusion defect. These changes are partly reversed with reperfusion.
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Affiliation(s)
- D Eidelberg
- NMR Research Group, National Hospital for Nervous Diseases, London, England
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Eidelberg D, Johnson G, Barnes D, Tofts PS, Delpy D, Plummer D, McDonald WI. 19F NMR imaging of blood oxygenation in the brain. Magn Reson Med 1988; 6:344-52. [PMID: 3362067 DOI: 10.1002/mrm.1910060312] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Perfluorocarbon (PFC) emulsions have been developed as oxygen carrying blood substitutes. High fluorine concentrations allow them to be used in 19F NMR imaging of blood vessels. Furthermore, 19F relaxation times in PFCs are dependent on oxygen tension (pO2) so that NMR imaging may provide a noninvasive method of measuring spatially localized pO2 values in vivo. Using these principles, we have formed 19F images and calculated pO2 maps of the cat brain.
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Affiliation(s)
- D Eidelberg
- NMR Research Group, Institute of Neurology, National Hospital for Nervous Diseases, Queen Square, London
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Clark LC, Spokane RB, Hoffmann RE, Sudan R, Homan MM, Maloney AC, Jacobs SJ, Stroup TL, Winston PE. Polarographic cerebral oxygen availability, fluorocarbon blood levels and efficacy of oxygen transport by emulsions. BIOMATERIALS, ARTIFICIAL CELLS, AND ARTIFICIAL ORGANS 1988; 16:375-93. [PMID: 3140920 DOI: 10.3109/10731198809132588] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
In order to relate blood perfluorocarbon (PFC) level to brain tissue oxygen availability (aO2) and respiratory oxygen (FIO2), twelve conscious rabbits with chronically implanted platinum cathodes were infused with six types of emulsions in 14 infusions and their response to oxygen and carbogen breathing recorded. Blood was removed for sampling and to avoid a volume overload. Blood lactate was measured as an indicator of adequacy of perfusion. Glucose, osmotic pressure, packed cell volume, PFC by combustion and volatilization were also measured in blood samples. Methyl prednisolone was administered to 5 rabbits. Blood PFC levels measured by the commonly used centrifugation method (Fluorocrit) were subject to considerable variation, depending mainly upon centrifugation time. Fluorocrit values after Oxypherol infusion decreased from an average of 43% for 5 minutes to 15% for 30 minutes centrifugation. Fluorocrit tended to slightly increase with time of centrifugation when phospholipid was used as the emulsifier, early in PFC infusion and on the next day. Blood fluorocarbon was always lower, about half that of 30 minutes of centrifugation, when determined by combustion or by volatilization, than by centrifugation. The increase in brain a O# response to oxygen and carbogen was observed at a lower PFC blood level than expected and in some animals appeared in either the right or left hemisphere, but not in both, suggesting that oxygen transport, at least near the electrode, was by other than oxygen solubility in blood PFC. Blood lactate proved to be an excellent monitor of whole body perfusion. Animals with a blood lactate above 5 mM/L at 1 hour post infusion died the following day. The fluorocrit after 5, 10, 20, and 30 minutes of centrifugation, which we have named the "fluoro-gram," can have a sharp downward, a slight upward curve, or stay level, depending upon the type of emulsifier, the amount of PFC circulating and the time it has circulated. The fluorocarbon-induced increases in aO2 persist through the third day. This enhanced cerebrocortical aO2 current can be very roughly calculated as: aO2 current equals the air aO2 current plus (the 30 minute fluorocrit times K) where K for oxygen is 0.05 and for carbogen is 0.07. Some enhancement of the aO2 current in oxygen lingers to the fifth day after the blood PFC level is vanishingly small. Methyl prednisolone has a transient effect in suppressing the PFC enhanced oxygen and carbogen aO2 responses and no effect on the Oxypherol fluorogram.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- L C Clark
- Children's Hospital Research Foundation, Cincinnati, Ohio
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44
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Kolluri S, DeGirolami U, Heros R, Vacanti F, Zervas N. Fluosol and experimental spinal cord ischemia. Acta Neuropathol 1988; 75:491-4. [PMID: 2454012 DOI: 10.1007/bf00687136] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Spinal cord ischemia was produced by temporary aortic occlusion for 12.5 min in 27 rabbits. Animals were divided into three groups: Group A received Fluosol DA 20% and 100% oxygen; Group B Fluosol and room air only, and Group C Dextran 40 and 100% oxygen. There was no difference in neurological outcome or in the extent and severity of histologically documented infarction of the spinal cord in the three groups. There was also no difference between these groups and untreated controls previously studied by us.
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Affiliation(s)
- S Kolluri
- Department of Surgery (Neurosurgery), Massachusetts General Hospital/Harvard Medical School, Boston 02114
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45
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Abstract
The interest in the possibility of cerebral resuscitation has been growing exponentially during the last decade. It became clear that pharmacotherapeutic interaction can possibly alter the outcome of cerebral hypoxia/ischemia. The present review is an attempt to provide an organizational framework for a systematic integration of studies specifically dealing with pharmacological treatment post-insult.
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Affiliation(s)
- A Wauquier
- Department of Neuropharmacology, Janssen Pharmaceutica, Beerse, Belgium
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46
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Abstract
This article presents information on medical applications of fluorocarbons. These inert chemicals have a high solubility for the respiratory gases and, in emulsified form, are present in the oxygen-transporting plasma substitutes now undergoing clinical trials. Oxygen content is directly related to arterial partial pressure of oxygen (PaO2). Thus, although oxygen transport of Fluosol-DA 20% (FDA) is only 0.75 ml per 100 ml per 10 kPa, oxygen delivery at the tissues will be adequate in the presence of a high PaO2. FDA has a low viscosity at low shear rates and this, together with a very small emulsion particle size of 0.1 micron, helps provide improved tissue oxygenation in conditions of ischaemic hypoxia. Fluorocarbon plasma substitutes may be employed as 'blood', but may also be used for a wide range of purposes in clinical practice. This review describes some current and potential future applications.
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47
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Light RB, Perez-Padilla R, Kryger MH. Perfluorochemical artificial blood as a volume expander in hypoxemic respiratory failure in dogs. Chest 1987; 91:444-9. [PMID: 3816321 DOI: 10.1378/chest.91.3.444] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The perfluorochemical O2-transport fluid, Fluosol-DA 20 percent (PFC), is being clinically evaluated as a volume expander in patients who are unable to receive blood products. Since patients treated with Fluosol-DA may be at risk of developing adult respiratory distress syndrome (ARDS) as a complication of the original disorder for which they were transfused, we examined central hemodynamics and gas exchange in anesthetized O2-ventilated dogs with oleic-acid induced pulmonary edema before and after transfusion with 400 ml of either PFC (n = 5) or whole blood (n = 5). Transfusion produced similar increases in cardiac output, pulmonary and systemic vascular pressures and intrapulmonary shunt in the two groups. Arterial O2 tension, however, fell from 209 +/- 117 to 172 +/- 81 mmHg in the blood transfused group but increased from 219 +/- 145 to 302 +/- 138 mmHg in the PFC group. Arterial O2 content, on the other hand, increased in the blood transfused group due to an increase in hematocrit, but fell with PFC because of hemodilution. This lower total arterial O2 content in the PFC group was, however, compensated for by more efficient O2 transport by the PFC in that the PFC arteriovenous O2 content difference accounted for 26 percent of the total arteriovenous O2 content difference, making it about four times as efficient as hemoglobin in tissue O2 delivery. Fluosol DA, 20 percent, is an effective volume expander in this model of hypoxemic respiratory failure, and it can transport significant amounts of O2 even in the presence of a substantial intrapulmonary shunt.
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48
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Meyer FB, Anderson RE, Sundt TM, Yaksh TL. Treatment of experimental focal cerebral ischemia with mannitol. Assessment by intracellular brain pH, cortical blood flow, and electroencephalography. J Neurosurg 1987; 66:109-15. [PMID: 3097275 DOI: 10.3171/jns.1987.66.1.0109] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Intracellular brain pH, cortical blood flow (CBF), and electrocorticograms were recorded in regions of severe and moderate ischemia in 10 control rabbits and 10 rabbits given mannitol, 1 gm/kg, after occlusion of a major branch of the middle cerebral artery. Pooling the data from all 20 animals, preocclusion CBF was 46.4 +/- 3.6 ml/100 gm/min and intracellular brain pH was 7.01 +/- 0.04 (means +/- standard error of the means). Although mannitol administration mildly improved CBF in regions of severe ischemia, this increase was not sufficient to prevent metabolic deterioration as assessed by brain pH. However, in regions of moderate ischemia, CBF improved significantly with mannitol and the gradual decline in brain pH observed in control animals was prevented. For example, in the treated moderate ischemia sites 4-hour postocclusion CBF and pH values were 31.8 ml/100 gm/min and 6.89 +/- 0.09, respectively, as compared to control values of 14.3 ml/100 gm/min and 6.75 +/- 0.06. These results suggest that mannitol may be of benefit in stabilizing regions of moderate, but not severe, ischemia after vessel occlusion.
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49
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Meyer FB, Sundt TM, Yanagihara T, Anderson RE. Focal cerebral ischemia: pathophysiologic mechanisms and rationale for future avenues of treatment. Mayo Clin Proc 1987; 62:35-55. [PMID: 3099103 DOI: 10.1016/s0025-6196(12)61523-7] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Although approximately 500,000 patients suffer from a stroke each year in the United States, treatment of these patients to date has consisted primarily of prevention, supportive measures, and rehabilitation. The modification of experimental cerebral infarction by new pharmacologic agents, along with encouraging results from the restoration of blood flow to areas of focal ischemia in both laboratory and clinical trials, suggests that a more aggressive approach might be considered in selected patients with acute stroke.
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Abstract
The salient physicochemical properties of the fluorocarbons are briefly reviewed, including their solubility for the physiologically important gases and their properties relevant to formulation (nonmiscibility with water). The preparations used to date are described, including their properties and compositions, with some comment about the available knowledge of the properties of the constituents. A critical review of the biological aspects and the possible uses of fluorocarbon emulsions constitutes the main body of the manuscript. Gas-transporting capabilities are considered quantitatively. The biological effects of these preparations are reviewed in in vivo, whole body systems, with some in vitro evidence where appropriate. The usefulness of these preparations investigated to date are reviewed under the broad headings of cardiovascular system, radiology, intoxications, and organ preservation. Finally, the shortcomings and potential usefulness are discussed, with recommendations for potential modifications.
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