1
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Yamamoto S, Kurokawa R, Kim P. Postdecompressive spinal cord blood flow increments in a cervical chronic myelopathy model in rats. J Neurosurg Spine 2021; 35:202-210. [PMID: 34144516 DOI: 10.3171/2020.11.spine201194] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 11/23/2020] [Indexed: 11/06/2022]
Abstract
OBJECTIVE In cervical spondylotic myelopathy (CSM), compromise of blood flow to the compressed spinal cord has been postulated to contribute to the development of myelopathy. Although decompressive surgery has been considered to improve spinal cord blood flow, evidence to support this notion is scarce. To determine whether blood flow improves after decompressive surgery for CSM, regional blood flow was measured in a model of chronic cervical compression in rats by using a fluorescent microsphere technique. METHODS Thin polyurethane sheets, measuring precisely 3 × 5 × 0.7 mm, were implanted under the C5-6 laminae in 24 rats to induce continuous compression on the cervical spinal cord. These sheets expand gradually by absorbing tissue fluid. This animal model has been demonstrated to reproduce the clinical features and histological changes of CSM, including progressive motor weakness with delayed onset and insidious tissue damage prior to symptom onset. Twenty-four rats that underwent sham operation were allocated to a control group. To confirm the development of cervical myelopathy, motor functions were measured weekly over the study period. Nine weeks after implantation of the sublaminar expanding sheets, histological studies and C5-6 decompressive surgery were conducted. Regional blood flow in the brainstem and cervical spinal cord was measured sequentially until 120 minutes after decompression. RESULTS In the CSM group, bilateral forepaw grip strength deteriorated progressively from 5 weeks after implantation. In the compressed C5-6 segment of the spinal cord, significant flattening of the cord, a decreased number of motor neurons, and vacuolations of gray matter were demonstrated. In the control group, blood flow in the brainstem and cervical spinal cord was unchanged by the decompressive surgery. In the CSM group, however, diminished blood flow and continuous blood flow increments for 120 minutes after decompression were demonstrated in the compressed C5-6 spinal cord segment. CONCLUSIONS Chronic mechanical compression induced regional spinal cord blood flow insufficiency concomitant with progressive neuronal loss and motor dysfunction in a chronic compression model in rats. Decompressive surgery increased spinal cord blood flow. These findings suggest that blood flow recovery may contribute to postoperative neurological improvement.
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Affiliation(s)
- Shinji Yamamoto
- 1Department of Neurosurgery, Ohnishi Neurological Center, Hyogo, Japan; and
- 2Department of Neurosurgery, Dokkyo University School of Medicine, Tochigi, Japan
| | - Ryu Kurokawa
- 2Department of Neurosurgery, Dokkyo University School of Medicine, Tochigi, Japan
| | - Phyo Kim
- 2Department of Neurosurgery, Dokkyo University School of Medicine, Tochigi, Japan
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2
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Zhu D, Hou J, Qian M, Jin D, Hao T, Pan Y, Wang H, Wu S, Liu S, Wang F, Wu L, Zhong Y, Yang Z, Che Y, Shen J, Kong D, Yin M, Zhao Q. Nitrate-functionalized patch confers cardioprotection and improves heart repair after myocardial infarction via local nitric oxide delivery. Nat Commun 2021; 12:4501. [PMID: 34301958 PMCID: PMC8302626 DOI: 10.1038/s41467-021-24804-3] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 07/05/2021] [Indexed: 02/07/2023] Open
Abstract
Nitric oxide (NO) is a short-lived signaling molecule that plays a pivotal role in cardiovascular system. Organic nitrates represent a class of NO-donating drugs for treating coronary artery diseases, acting through the vasodilation of systemic vasculature that often leads to adverse effects. Herein, we design a nitrate-functionalized patch, wherein the nitrate pharmacological functional groups are covalently bound to biodegradable polymers, thus transforming small-molecule drugs into therapeutic biomaterials. When implanted onto the myocardium, the patch releases NO locally through a stepwise biotransformation, and NO generation is remarkably enhanced in infarcted myocardium because of the ischemic microenvironment, which gives rise to mitochondrial-targeted cardioprotection as well as enhanced cardiac repair. The therapeutic efficacy is further confirmed in a clinically relevant porcine model of myocardial infarction. All these results support the translational potential of this functional patch for treating ischemic heart disease by therapeutic mechanisms different from conventional organic nitrate drugs.
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Affiliation(s)
- Dashuai Zhu
- State key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials (Ministry of Education), College of Life Sciences, Nankai University, Tianjin, China
- School of Medicine, Nankai University, Tianjin, China
| | - Jingli Hou
- Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnostics, School of Pharmacy, Tianjin Medical University, Tianjin, China
| | - Meng Qian
- State key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials (Ministry of Education), College of Life Sciences, Nankai University, Tianjin, China
| | - Dawei Jin
- Department of Cardiothoracic Surgery, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Tian Hao
- State key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials (Ministry of Education), College of Life Sciences, Nankai University, Tianjin, China
| | - Yanjun Pan
- Department of Cardiothoracic Surgery, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - He Wang
- State key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials (Ministry of Education), College of Life Sciences, Nankai University, Tianjin, China
| | - Shuting Wu
- Department of Cardiothoracic Surgery, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Shuo Liu
- School of Medicine, Nankai University, Tianjin, China
| | - Fei Wang
- State key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials (Ministry of Education), College of Life Sciences, Nankai University, Tianjin, China
| | - Lanping Wu
- Department of Cardiac Ultrasound, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yumin Zhong
- Diagnostic Imaging Center, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Zhilu Yang
- Key Laboratory of Advanced Technology for Materials of Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, China
| | - Yongzhe Che
- School of Medicine, Nankai University, Tianjin, China
| | - Jie Shen
- College of Pharmacy, Nankai University, Tianjin, China
| | - Deling Kong
- State key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials (Ministry of Education), College of Life Sciences, Nankai University, Tianjin, China
| | - Meng Yin
- Department of Cardiothoracic Surgery, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
| | - Qiang Zhao
- State key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials (Ministry of Education), College of Life Sciences, Nankai University, Tianjin, China.
- Zhengzhou Cardiovascular Hospital and 7th People's Hospital of Zhengzhou, Zhengzhou, Henan Province, China.
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3
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MohanKumar K, Namachivayam K, Song T, Jake Cha B, Slate A, Hendrickson JE, Pan H, Wickline SA, Oh JY, Patel RP, He L, Torres BA, Maheshwari A. A murine neonatal model of necrotizing enterocolitis caused by anemia and red blood cell transfusions. Nat Commun 2019; 10:3494. [PMID: 31375667 PMCID: PMC6677753 DOI: 10.1038/s41467-019-11199-5] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 06/27/2019] [Indexed: 12/23/2022] Open
Abstract
Necrotizing enterocolitis (NEC) is an idiopathic, inflammatory bowel necrosis of premature infants. Clinical studies have linked NEC with antecedent red blood cell (RBC) transfusions, but the underlying mechanisms are unclear. Here we report a neonatal murine model to investigate this association. C57BL/6 mouse pups rendered anemic by timed phlebotomy and then given RBC transfusions develop NEC-like intestinal injury with prominent necrosis, inflammation, and submucosal edema/separation of the lamina propria in the ileocecal region and colon within 12-24 h. The anemic intestine is infiltrated by inflammatory macrophages, which are activated in situ by RBC transfusions via a Toll-like receptor (TLR)-4-mediated mechanism and cause bowel injury. Chelation of RBC degradation products with haptoglobin, absence of TLR4, macrophage depletion, and inhibition of macrophage activation is protective. Intestinal injury worsens with increasing severity and the duration of anemia prior to transfusion, indicating a need for the re-evaluation of current transfusion guidelines for premature infants.
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MESH Headings
- Anemia/complications
- Anemia/therapy
- Animals
- Animals, Newborn
- Cecum/pathology
- Colon/pathology
- Disease Models, Animal
- Enterocolitis, Necrotizing/etiology
- Enterocolitis, Necrotizing/pathology
- Erythrocyte Transfusion/adverse effects
- Humans
- Ileum/pathology
- Infant, Newborn
- Infant, Newborn, Diseases/etiology
- Infant, Newborn, Diseases/pathology
- Infant, Premature
- Intestinal Mucosa/pathology
- Macrophages/immunology
- Macrophages/metabolism
- Mice
- Toll-Like Receptor 4/immunology
- Toll-Like Receptor 4/metabolism
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Affiliation(s)
- Krishnan MohanKumar
- Department of Pediatrics, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA
- Department of Pediatrics, Johns Hopkins University, Baltimore, MD, 21287, USA
| | - Kopperuncholan Namachivayam
- Department of Pediatrics, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA
- Department of Pediatrics, Johns Hopkins University, Baltimore, MD, 21287, USA
| | - Tanjing Song
- Department of Pediatrics, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA
| | - Byeong Jake Cha
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA
| | - Andrea Slate
- Department of Comparative Medicine, University of South Florida, Tampa, FL, 33612, USA
- Center for Comparative Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Jeanne E Hendrickson
- Department of Laboratory Medicine, Yale School of Medicine, New Haven, CT, 06520, USA
- Department of Pediatrics, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Hua Pan
- Department of Cardiology, Morsani College of Medicine, University of South Florida, Tampa, FL, 33629, USA
| | - Samuel A Wickline
- Department of Cardiology, Morsani College of Medicine, University of South Florida, Tampa, FL, 33629, USA
| | - Joo-Yeun Oh
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Rakesh P Patel
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Ling He
- Department of Pediatrics, Johns Hopkins University, Baltimore, MD, 21287, USA
| | - Benjamin A Torres
- Department of Pediatrics, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA
| | - Akhil Maheshwari
- Department of Pediatrics, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA.
- Department of Pediatrics, Johns Hopkins University, Baltimore, MD, 21287, USA.
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4
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Proctor AR, Ramirez GA, Han S, Liu Z, Bubel TM, Choe R. Validation of diffuse correlation spectroscopy sensitivity to nicotinamide-induced blood flow elevation in the murine hindlimb using the fluorescent microsphere technique. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-9. [PMID: 29595019 PMCID: PMC5873645 DOI: 10.1117/1.jbo.23.3.035006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 03/06/2018] [Indexed: 05/15/2023]
Abstract
Nicotinamide has been shown to affect blood flow in both tumor and normal tissues, including skeletal muscle. Intraperitoneal injection of nicotinamide was used as a simple intervention to test the sensitivity of noninvasive diffuse correlation spectroscopy (DCS) to changes in blood flow in the murine left quadriceps femoris skeletal muscle. DCS was then compared with the gold-standard fluorescent microsphere (FM) technique for validation. The nicotinamide dose-response experiment showed that relative blood flow measured by DCS increased following treatment with 500- and 1000-mg / kg nicotinamide. The DCS and FM technique comparison showed that blood flow index measured by DCS was correlated with FM counts quantified by image analysis. The results of this study show that DCS is sensitive to nicotinamide-induced blood flow elevation in the murine left quadriceps femoris. Additionally, the results of the comparison were consistent with similar studies in higher-order animal models, suggesting that mouse models can be effectively employed to investigate the utility of DCS for various blood flow measurement applications.
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Affiliation(s)
- Ashley R. Proctor
- University of Rochester, Department of Biomedical Engineering, Rochester, New York, United States
| | - Gabriel A. Ramirez
- University of Rochester, Department of Biomedical Engineering, Rochester, New York, United States
| | - Songfeng Han
- University of Rochester, Institute of Optics, Rochester, New York, United States
| | - Ziping Liu
- University of Rochester, Department of Biomedical Engineering, Rochester, New York, United States
| | - Tracy M. Bubel
- University of Rochester, Center for Visual Science, Rochester, New York, United States
| | - Regine Choe
- University of Rochester, Department of Biomedical Engineering, Rochester, New York, United States
- University of Rochester, Department of Electrical and Computer Engineering, Rochester, New York, United States
- Address all correspondence to: Regine Choe, E-mail:
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5
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Zhang Y, Cattrall RW, Kolev SD. Fast and Environmentally Friendly Microfluidic Technique for the Fabrication of Polymer Microspheres. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:14691-14698. [PMID: 29227109 DOI: 10.1021/acs.langmuir.7b03574] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
This paper reports on a novel microfluidic technique for the fabrication of microspheres of synthetic polymers including poly(vinyl chloride) (PVC), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), poly(lactic acid) (PLA), and polystyrene (PS). The polymers are dissolved in tetrahydrofuran (THF) and the method is based on the diminished solubility of THF in a 20% (w/v) NaCl solution which allows the formation of droplets of the polymer solution. These polymer solution droplets are generated in a microfluidic system and their desolvation is accomplished within seconds by allowing the droplets to rise by buoyancy through a NaCl solution with a concentration lower than 15%. The size and morphology of the resultant polymer microspheres have been investigated by optical and scanning electron microscopy. Apart from the elimination of the use of highly toxic solvents as in conventional methods for manufacturing of polymer microspheres, the newly developed technique has the advantages of providing faster desolvation of the polymer solution droplets and a higher yield of microspheres compared to emulsification-based techniques.
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Affiliation(s)
- Yanlin Zhang
- School of Chemistry, The University of Melbourne , Victoria 3010, Australia
| | - Robert W Cattrall
- School of Chemistry, The University of Melbourne , Victoria 3010, Australia
| | - Spas D Kolev
- School of Chemistry, The University of Melbourne , Victoria 3010, Australia
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6
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Wang J, Wang Q, Zheng Y, Peng T, Yao K, Xie S, Zhang X, Xia X, Li J, Jiang H. Development of a quantitative fluorescence-based lateral flow immunoassay for determination of chloramphenicol, thiamphenicol and florfenicol in milk. FOOD AGR IMMUNOL 2017. [DOI: 10.1080/09540105.2017.1359498] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Jianyi Wang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing, People’s Republic of China
| | - Qi Wang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing, People’s Republic of China
| | - Yongjun Zheng
- Department of Mechanical and Electrical Engineering, College of Engineering, China Agricultural University, Beijing, People’s Republic of China
| | - Tao Peng
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing, People’s Republic of China
| | - Kai Yao
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing, People’s Republic of China
| | - Sanlei Xie
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing, People’s Republic of China
| | - Xiya Zhang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing, People’s Republic of China
| | - Xi Xia
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing, People’s Republic of China
| | - Jiancheng Li
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing, People’s Republic of China
| | - Haiyang Jiang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agricultural University, Beijing, People’s Republic of China
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7
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Coats B, Binenbaum G, Smith C, Peiffer RL, Christian CW, Duhaime AC, Margulies SS. Cyclic Head Rotations Produce Modest Brain Injury in Infant Piglets. J Neurotrauma 2016; 34:235-247. [PMID: 26953505 DOI: 10.1089/neu.2015.4352] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Repetitive back-and-forth head rotation from vigorous shaking is purported to be a central mechanism responsible for diffuse white matter injury, subdural hemorrhage, and retinal hemorrhage in some cases of abusive head trauma (AHT) in young children. Although animal studies have identified mechanisms of traumatic brain injury (TBI) associated with single rapid head acceleration-decelerations at levels experienced in a motor vehicle crash, few experimental studies have investigated TBI from repetitive head rotations. The objective of this study was to systematically investigate the post-injury pathological time-course after cyclic, low-velocity head rotations in the piglet and compare them with single head rotations. Injury metrics were the occurrence and extent of axonal injury (AI), extra-axial hemorrhage (EAH), red cell neuronal/axonal change (RCNAC), and ocular injury (OI). Hyperflexion/extension of the neck were purposefully avoided in the study, resulting in unscaled angular accelerations at the lower end of reported infant surrogate shaking kinematics. All findings were at the mild end of the injury spectrum, with no significant findings at 6 h post-injury. Cyclic head rotations, however, produced modest AI that significantly increased with time post-injury (p < 0.035) and had significantly greater amounts of RCNAC and EAH than noncyclic head rotations after 24 h post-injury (p < 0.05). No OI was observed. Future studies should investigate the contributions of additional physiological and mechanical features associated with AHT (e.g., hyperflexion/extension, increased intracranial pressure from crying or thoracic compression, and more than two cyclic episodes) to enhance our understanding of the causality between proposed mechanistic factors and AHT in infants.
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Affiliation(s)
- Brittany Coats
- 1 Department of Mechanical Engineering, University of Utah , Salt Lake City, Utah
| | - Gil Binenbaum
- 2 Department of Ophthalmology, Children's Hospital of Philadelphia , Philadelphia, Pennsylvania.,3 Department of Ophthalmology, University of Pennsylvania , Philadelphia, Pennsylvania
| | - Colin Smith
- 4 Department Pathology, Edinburgh University , Edinburgh, Scotland
| | - Robert L Peiffer
- 3 Department of Ophthalmology, University of Pennsylvania , Philadelphia, Pennsylvania
| | - Cindy W Christian
- 5 Department of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania , Philadelphia, Pennsylvania
| | - Ann-Christine Duhaime
- 6 Department of Neurosurgery, Massachusetts General Hospital and Harvard University , Boston, Massachusetts
| | - Susan S Margulies
- 7 Department of Bioengineering, University of Pennsylvania , Philadelphia, Pennsylvania
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8
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Brew N, Walker D, Wong FY. Cerebral vascular regulation and brain injury in preterm infants. Am J Physiol Regul Integr Comp Physiol 2014; 306:R773-86. [PMID: 24647591 DOI: 10.1152/ajpregu.00487.2013] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cerebrovascular lesions, mainly germinal matrix hemorrhage and ischemic injury to the periventricular white matter, are major causes of adverse neurodevelopmental outcome in preterm infants. Cerebrovascular lesions and neuromorbidity increase with decreasing gestational age, with the white matter predominantly affected. Developmental immaturity in the cerebral circulation, including ongoing angiogenesis and vasoregulatory immaturity, plays a major role in the severity and pattern of preterm brain injury. Prevention of this injury requires insight into pathogenesis. Cerebral blood flow (CBF) is low in the preterm white matter, which also has blunted vasoreactivity compared with other brain regions. Vasoreactivity in the preterm brain to cerebral perfusion pressure, oxygen, carbon dioxide, and neuronal metabolism is also immature. This could be related to immaturity of both the vasculature and vasoactive signaling. Other pathologies arising from preterm birth and the neonatal intensive care environment itself may contribute to impaired vasoreactivity and ineffective CBF regulation, resulting in the marked variations in cerebral hemodynamics reported both within and between infants depending on their clinical condition. Many gaps exist in our understanding of how neonatal treatment procedures and medications have an impact on cerebral hemodynamics and preterm brain injury. Future research directions for neuroprotective strategies include establishing cotside, real-time clinical reference values for cerebral hemodynamics and vasoregulatory capacity and to demonstrate that these thresholds improve long-term outcomes for the preterm infant. In addition, stimulation of vascular development and repair with growth factor and cell-based therapies also hold promise.
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Affiliation(s)
- Nadine Brew
- The Ritchie Centre, Monash Institute of Medical Research-Prince Henry's Institute, Melbourne, Clayton, Victoria, Australia; and
| | - David Walker
- The Ritchie Centre, Monash Institute of Medical Research-Prince Henry's Institute, Melbourne, Clayton, Victoria, Australia; and Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia
| | - Flora Y Wong
- The Ritchie Centre, Monash Institute of Medical Research-Prince Henry's Institute, Melbourne, Clayton, Victoria, Australia; and Monash Newborn, Monash Medical Centre, Melbourne, Victoria, Australia; and Department of Pediatrics, Monash University, Melbourne, Victoria, Australia
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9
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Mesquita RC, D’Souza A, Bilfinger TV, Galler RM, Emanuel A, Schenkel SS, Yodh AG, Floyd TF. Optical monitoring and detection of spinal cord ischemia. PLoS One 2013; 8:e83370. [PMID: 24358279 PMCID: PMC3865183 DOI: 10.1371/journal.pone.0083370] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 11/01/2013] [Indexed: 12/14/2022] Open
Abstract
Spinal cord ischemia can lead to paralysis or paraparesis, but if detected early it may be amenable to treatment. Current methods use evoked potentials for detection of spinal cord ischemia, a decades old technology whose warning signs are indirect and significantly delayed from the onset of ischemia. Here we introduce and demonstrate a prototype fiber optic device that directly measures spinal cord blood flow and oxygenation. This technical advance in neurological monitoring promises a new standard of care for detection of spinal cord ischemia and the opportunity for early intervention. We demonstrate the probe in an adult Dorset sheep model. Both open and percutaneous approaches were evaluated during pharmacologic, physiological, and mechanical interventions designed to induce variations in spinal cord blood flow and oxygenation. The induced variations were rapidly and reproducibly detected, demonstrating direct measurement of spinal cord ischemia in real-time. In the future, this form of hemodynamic spinal cord diagnosis could significantly improve monitoring and management in a broad range of patients, including those undergoing thoracic and abdominal aortic revascularization, spine stabilization procedures for scoliosis and trauma, spinal cord tumor resection, and those requiring management of spinal cord injury in intensive care settings.
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Affiliation(s)
- Rickson C. Mesquita
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Institute of Physics, University of Campinas, Campinas, São Paulo, Brazil
| | - Angela D’Souza
- Department of Anesthesiology, Stony Brook University Medical Center, Stony Brook, New York, United States of America
- Department of Biomedical Engineering, Stony Brook University Medical Center, Stony Brook, New York, United States of America
| | - Thomas V. Bilfinger
- Department of Surgery, Stony Brook University Medical Center, Stony Brook, New York, United States of America
| | - Robert M. Galler
- Department of Neurosurgery, Stony Brook University Medical Center, Stony Brook, New York, United States of America
| | - Asher Emanuel
- Department of Anesthesiology, Stony Brook University Medical Center, Stony Brook, New York, United States of America
| | - Steven S. Schenkel
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Arjun G. Yodh
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Thomas F. Floyd
- Department of Anesthesiology, Stony Brook University Medical Center, Stony Brook, New York, United States of America
- Department of Biomedical Engineering, Stony Brook University Medical Center, Stony Brook, New York, United States of America
- * E-mail:
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10
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Chen R, Li H, Zhang H, Zhang S, Shi W, Shen J, Wang Z. Development of a lateral flow fluorescent microsphere immunoassay for the determination of sulfamethazine in milk. Anal Bioanal Chem 2013; 405:6783-9. [DOI: 10.1007/s00216-013-7150-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 06/01/2013] [Accepted: 06/14/2013] [Indexed: 10/26/2022]
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11
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Abstract
RATIONALE The spatial distribution of blood flow in the hearts of genetically modified mice is a phenotype of interest because derangements in blood flow may precede detectable changes in organ function. However, quantifying the regional distribution of blood flow within organs of mice is challenging because of the small organ volume and the high resolution required to observe spatial differences in flow. Traditional microsphere methods in which the numbers of microspheres per region are indirectly estimated from radioactive counts or extracted fluorescence have been limited to larger organs for 2 reasons; to ensure statistical confidence in the measured flow per region and to be able to physically dissect the organ to acquire spatial information. OBJECTIVE To develop methods to quantify and statistically compare the spatial distribution of blood flow within organs of mice. METHODS AND RESULTS We developed and validated statistical methods to compare blood flow between regions and with the same regions over time using 15-µm fluorescent microspheres. We then tested this approach by injecting fluorescent microspheres into isolated perfused mice hearts, determining the spatial location of every microsphere in the hearts, and then visualizing regional flow patterns. We demonstrated application of these statistical and visualizing methods in a coronary artery ligation model in mice. CONCLUSIONS These new methods provide tools to investigate the spatial and temporal changes in blood flow within organs of mice at a much higher spatial resolution than currently available by other methods.
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Affiliation(s)
- Melissa A Krueger
- Division of Pulmonary and Critical Care Medicine, Box 356522, University of Washington School of Medicine, Seattle, WA 98195, USA.
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12
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Wang J, Ginther RM, Riegel M, Huang R, Sharma MS, Guleserian KJ, Forbess JM. The impact of temperature and pump flow rate during selective cerebral perfusion on regional blood flow in piglets. J Thorac Cardiovasc Surg 2012; 145:188-94; discussion 194-5. [PMID: 23141032 DOI: 10.1016/j.jtcvs.2012.09.055] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 09/12/2012] [Accepted: 09/21/2012] [Indexed: 10/27/2022]
Abstract
OBJECTIVE Ideal temperature and flow rate for selective cerebral perfusion (SCP) are not known. We examined regional organ perfusion in a piglet SCP model. METHODS Three groups underwent SCP at 30 mL/kg/min at different temperatures (15°C, 25°C, and 32°C) and 4 groups remained at 25°C for SCP at different flow rates (10, 30, 50 and 75 mL/kg/min). Fluorescent microspheres were injected at 5 minutes of normothermic cardiopulmonary bypass (CPB), immediately before SCP, SCP 45 minutes, SCP 90 minutes, and 2 hours after CPB. Brain and lower body organs were collected to examine regional blood flow (RBF, mL/min/g). RESULTS At 2 hours after CPB, RBF of the 32°C group was higher than that of the 15°C group (P < .05) at the caudate nucleus and hippocampus; RBF of the 32°C group was higher than that of the 25°C and 15°C groups (P < .05) at the neocortex. No significant difference in RBF was observed among any of the 25°C groups at different flow rates. Also, there was no significant difference between the RBF to the left and right sides of brain in either the temperature or flow rate groups. RBF did significantly increase with temperature in the liver and quadriceps during SCP (P < .05). At the kidney, RBF at SCP 90 minutes was significantly higher than that at SCP 45 minutes when all temperature groups were combined (P < .05). CONCLUSIONS SCP at 32°C provides higher brain RBF 2 hours after CPB. Increasing SCP flow rate does not increase RBF significantly at 25°C. Higher temperature during SCP results in improved RBF to the liver and quadriceps.
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Affiliation(s)
- Jian Wang
- Division of Pediatric Cardiothoracic Surgery, University of Texas Southwestern Medical Center, Dallas, Tex 75235, USA
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Oláh O, Németh I, Tóth-Szuki V, Bari F, Domoki F. Regional Differences in the Neuronal Expression of Cyclooxygenase-2 (COX-2) in the Newborn Pig Brain. Acta Histochem Cytochem 2012; 45:187-92. [PMID: 22829712 PMCID: PMC3395304 DOI: 10.1267/ahc.11056] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Accepted: 03/21/2012] [Indexed: 11/22/2022] Open
Abstract
Cyclooxygenase (COX)-2 is the major constitutively expressed COX isoform in the newborn brain. COX-2 derived prostanoids and reactive oxygen species appear to play a major role in the mechanism of perinatal hypoxic-ischemic injury in the newborn piglet, an accepted animal model of the human term neonate. The study aimed to quantitatively determine COX-2 immunopositive neurons in different brain regions in piglets under normoxic conditions (n=15), and 4 hours after 10 min asphyxia (n=11). Asphyxia did not induce significant changes in neuronal COX-2 expression of any studied brain areas. In contrast, there was a marked regional difference in all experimental groups. Thus, significant difference was observed between fronto-parietal and temporo-occipital regions: 59±4% and 67±3% versus 41±2%* and 31±3%* respectively (mean±SEM, data are pooled from all subjects, n=26, *p<0.05, vs. fronto-parietal region). In the hippocampus, COX-2 immunopositivity was rare (highest expression in CA1 region: 14±2%). The studied subcortical areas showed negligible COX-2 staining. Our findings suggest that asphyxia does not significantly alter the pattern of neuronal COX-2 expression in the early reventilation period. Furthermore, based on the striking differences observed in cortical neuronal COX-2 distribution, the contribution of COX-2 mediated neuronal injury after asphyxia may also show region-specific differences.
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Affiliation(s)
- Orsolya Oláh
- Department of Physiology, University of Szeged School of Medicine
- Department of Physiology, University of Szeged School of Medicine
| | - István Németh
- Department of Dermatology and Allergology, University of Szeged School of Medicine
- Department of Dermatology and Allergology, University of Szeged School of Medicine
| | - Valéria Tóth-Szuki
- Department of Physiology, University of Szeged School of Medicine
- Department of Physiology, University of Szeged School of Medicine
| | - Ferenc Bari
- Department of Medical Physics and Informatics, University of Szeged School of Medicine
- Department of Medical Physics and Informatics, University of Szeged School of Medicine
| | - Ferenc Domoki
- Department of Physiology, University of Szeged School of Medicine
- Department of Physiology, University of Szeged School of Medicine
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Zhang H, Qiao H, Frank RS, Huang B, Propert KJ, Margulies S, Ferrari VA, Epstein JA, Zhou R. Spin-labeling magnetic resonance imaging detects increased myocardial blood flow after endothelial cell transplantation in the infarcted heart. Circ Cardiovasc Imaging 2012; 5:210-7. [PMID: 22311739 DOI: 10.1161/circimaging.111.966317] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND We quantified absolute myocardial blood flow (MBF) using a spin-labeling MRI (SL-MRI) method after transplantation of endothelial cells (ECs) into the infarcted heart. Our aims were to study the temporal changes in MBF in response to EC transplantation and to compare regional MBF with contractile function (wall motion) and microvascular density. METHODS AND RESULTS We first validated the SL-MRI method with the standard microsphere technique in normal rats. We then induced myocardial infarction in athymic rats and injected 5 million ECs (human umbilical vein endothelial cells) suspended in Matrigel or Matrigel alone (vehicle) along the border of the blanched infarcted area. At 2 weeks after myocardial infarction, MBF averaged over the entire slice (P=0.038) and in the infarcted region (P=0.0086) was significantly higher in EC versus vehicle group; the greater MBF was accompanied by an increase of microvasculature density in the infarcted region (P=0.0105 versus vehicle). At 4 weeks after myocardial infarction, MBF in the remote region was significantly elevated in EC-treated hearts (P=0.0277); this was accompanied by increased wall motion in this region assessed by circumferential strains (P=0.0075). Intraclass correlation coefficients and Bland-Altman plot revealed a good reproducibility of the SL-MRI method. CONCLUSIONS MBF in free-breathing rats measured by SL-MRI is validated by the standard color microsphere technique. SL-MRI allows quantification of temporal changes of regional MBF in response to EC treatment. The proof-of-principle study indicates that MBF is a unique and sensitive index to evaluate EC-mediated therapy for the infarcted heart.
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Affiliation(s)
- Hualei Zhang
- Laboratories of Molecular Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA
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Eucker SA, Smith C, Ralston J, Friess SH, Margulies SS. Physiological and histopathological responses following closed rotational head injury depend on direction of head motion. Exp Neurol 2010; 227:79-88. [PMID: 20875409 DOI: 10.1016/j.expneurol.2010.09.015] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Revised: 08/31/2010] [Accepted: 09/21/2010] [Indexed: 10/19/2022]
Abstract
Rotational inertial forces are thought to be the underlying mechanism for most severe brain injuries. However, little is known about the effect of head rotation direction on injury outcomes, particularly in the pediatric population. Neonatal piglets were subjected to a single non-impact head rotation in the horizontal, coronal, or sagittal direction, and physiological and histopathological responses were observed. Sagittal rotation produced the longest duration of unconsciousness, highest incidence of apnea, and largest intracranial pressure increase, while coronal rotation produced little change, and horizontal rotation produced intermediate and variable derangements. Significant cerebral blood flow reductions were observed following sagittal but not coronal or horizontal injury compared to sham. Subarachnoid hemorrhage, ischemia, and brainstem pathology were observed in the sagittal and horizontal groups but not in a single coronal animal. Significant axonal injury occurred following both horizontal and sagittal rotations. For both groups, the distribution of injury was greater in the frontal and parietotemporal lobes than in the occipital lobes, frequently occurred in the absence of ischemia, and did not correlate with regional cerebral blood flow reductions. We postulate that these direction-dependent differences in injury outcomes are due to differences in tissue mechanical loading produced during head rotation.
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Affiliation(s)
- Stephanie A Eucker
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA 19104, USA
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