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Giordani M, Meli MA, Roselli C, Betti M, Peruzzi F, Taussi M, Valentini L, Fagiolino I, Mattioli M. Could soluble minerals be hazardous to human health? Evidence from fibrous epsomite. ENVIRONMENTAL RESEARCH 2022; 206:112579. [PMID: 34968437 DOI: 10.1016/j.envres.2021.112579] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 12/03/2021] [Accepted: 12/12/2021] [Indexed: 06/14/2023]
Abstract
From a toxicological point of view, particulates and fibres with high solubility in water and/or in biological environments have not been considered in detail and the knowledge to date in this area is very scarce. In this study, the water-soluble natural epsomite fibres from Perticara Mine (Italy) were investigated using SEM-EDS, XRPD, ICP-AES and alpha spectrometry measurements which were combined and integrated to characterise the fibres' morphology, crystal chemistry and mineralogy. The morphological and morphometric results showed that most of the fibres are of inhalable size (Dae 5.09 μm) and can be potentially adsorbed from all parts of the respiratory tract. Chemical analysis reveals significant amounts of toxic elements (As, Co, Fe, Mn, Ni, Sr, Ti, Zn) and surprisingly high contents of radioactive isotopes (210Po and 228Th) in epsomite crystals, making the inhalation of these fibres potentially hazardous to human health. Through this study, we want to focus on soluble minerals, such as epsomite, which can be present in both natural and anthropic environments and have never been considered from the point of view of their potential hazard.
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Affiliation(s)
- Matteo Giordani
- Department of Pure and Applied Sciences, University of Urbino Carlo Bo, Urbino, Italy.
| | - Maria Assunta Meli
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Carla Roselli
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Michele Betti
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Fabio Peruzzi
- Speleological Federation of the Emilia-Romagna Region, Bologna, Italy
| | - Marco Taussi
- Department of Pure and Applied Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | - Laura Valentini
- Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, Italy
| | | | - Michele Mattioli
- Department of Pure and Applied Sciences, University of Urbino Carlo Bo, Urbino, Italy
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2
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O'Neil DA, Nicholas MA, Lajud N, Kline AE, Bondi CO. Preclinical Models of Traumatic Brain Injury: Emerging Role of Glutamate in the Pathophysiology of Depression. Front Pharmacol 2018; 9:579. [PMID: 29910733 PMCID: PMC5992468 DOI: 10.3389/fphar.2018.00579] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 05/15/2018] [Indexed: 12/19/2022] Open
Abstract
More than 10 million people worldwide incur a traumatic brain injury (TBI) each year, with two million cases occurring in the United States. TBI survivors exhibit long-lasting cognitive and affective sequelae that are associated with reduced quality of life and work productivity, as well as mental and emotional disturbances. While TBI-related disabilities often manifest physically and conspicuously, TBI has been linked with a "silent epidemic" of psychological disorders, including major depressive disorder (MDD). The prevalence of MDD post-insult is approximately 50% within the 1st year. Furthermore, given they are often under-reported when mild, TBIs could be a significant overall cause of MDD in the United States. The emergence of MDD post-TBI may be rooted in widespread disturbances in the modulatory role of glutamate, such that glutamatergic signaling becomes excessive and deleterious to neuronal integrity, as reported in both clinical and preclinical studies. Following this acute glutamatergic storm, regulators of glutamatergic function undergo various manipulations, which include, but are not limited to, alterations in glutamatergic subunit composition, release, and reuptake. This review will characterize the glutamatergic functional and signaling changes that emerge and persist following experimental TBI, utilizing evidence from clinical, molecular, and rodent behavioral investigations. Special care will be taken to speculate on how these manipulations may correlate with the development of MDD following injury in the clinic, as well as pharmacotherapies to date. Indisputably, TBI is a significant healthcare issue that warrants discovery and subsequent refinement of therapeutic strategies to improve neurobehavioral recovery and mental health.
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Affiliation(s)
- Darik A O'Neil
- Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States.,Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA, United States
| | - Melissa A Nicholas
- Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States.,Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA, United States
| | - Naima Lajud
- Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States.,Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA, United States.,División de Neurociencias, Centro de Investigación Biomédica de Michoacán - Instituto Mexicano del Seguro Social, Morelia, Mexico
| | - Anthony E Kline
- Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States.,Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA, United States.,Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States.,Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, United States.,Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, United States.,Department of Psychology, University of Pittsburgh, Pittsburgh, PA, United States
| | - Corina O Bondi
- Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States.,Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA, United States.,Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States.,Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA, United States.,Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, United States
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3
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Huang Z, Filipovic Z, Mp N, Ung C, Troy EL, Colburn RW, Iaci JF, Hackett C, Button DC, Caggiano AO, Parry TJ. AC105 Increases Extracellular Magnesium Delivery and Reduces Excitotoxic Glutamate Exposure within Injured Spinal Cords in Rats. J Neurotrauma 2016; 34:685-694. [PMID: 27503053 DOI: 10.1089/neu.2016.4607] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Magnesium (Mg2+) homeostasis is impaired following spinal cord injury (SCI) and the loss of extracellular Mg2+ contributes to secondary injury by various mechanisms, including glutamate neurotoxicity. The neuroprotective effects of high dose Mg2+ supplementation have been reported in many animal models. Recent studies found that lower Mg2+ doses also improved neurologic outcomes when Mg2+ was formulated with polyethylene glycol (PEG), suggesting that a PEG/ Mg2+ formulation might increase Mg2+ delivery to the injured spinal cord, compared with that of MgSO4 alone. Here, we assessed spinal extracellular Mg2+ and glutamate levels following SCI in rats using microdialysis. Basal levels of extracellular Mg2+ (∼0.5 mM) were significantly reduced to 0.15 mM in the core and 0.12 mM in the rostral peri-lesion area after SCI. A single intravenous infusion of saline or of MgSO4 at 192 μmoL/kg did not significantly change extracellular Mg2+ concentrations. However, a single infusion of AC105 (a MgCl2 in PEG) at an equimolar Mg2+ dose significantly increased the Mg2+ concentration to 0.3 mM (core area) and 0.25 mM (rostral peri-lesion area). Moreover, multiple AC105 treatments completely restored the depleted extracellular Mg2+ concentrations after SCI to levels in the uninjured spinal cord. Repeated MgSO4 infusions slightly increased the Mg2+ concentrations while saline infusion had no effect. In addition, AC105 treatment significantly reduced extracellular glutamate levels in the lesion center after SCI. These results indicate that intravenous infusion of PEG-formulated Mg2+ normalized the Mg2+ homeostasis following SCI and reduced potentially neurotoxic glutamate levels, consistent with a neuroprotective mechanism of blocking excitotoxicity.
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Affiliation(s)
| | | | | | - Chia Ung
- Acorda Therapeutics, Inc. , Ardsley, New York
| | | | | | | | | | | | | | - Tom J Parry
- Acorda Therapeutics, Inc. , Ardsley, New York
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4
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Xia Y, Bo A, Liu Z, Chi B, Su Z, Hu Y, Luo R, Su X, Sun J. Effects of magnesium sulfate on apoptosis in cultured human gastric epithelial cells. FOOD AGR IMMUNOL 2015. [DOI: 10.1080/09540105.2015.1079596] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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5
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Humphrey S, Kirby R, Rudloff E. Magnesium physiology and clinical therapy in veterinary critical care. J Vet Emerg Crit Care (San Antonio) 2014; 25:210-25. [PMID: 25427407 DOI: 10.1111/vec.12253] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 09/30/2014] [Indexed: 12/26/2022]
Abstract
OBJECTIVE To review magnesium physiology including absorption, excretion, and function within the body, causes of magnesium abnormalities, and the current applications of magnesium monitoring and therapy in people and animals. ETIOLOGY Magnesium plays a pivotal role in energy production and specific functions in every cell in the body. Disorders of magnesium can be correlated with severity of disease, length of hospital stay, and recovery of the septic patient. Hypermagnesemia is seen infrequently in people and animals with significant consequences reported. Hypomagnesemia is more common in critically ill people and animals, and can be associated with platelet, immune system, neurological, and cardiovascular dysfunction as well as alterations in insulin responsiveness and electrolyte imbalance. DIAGNOSIS Measurement of serum ionized magnesium in critically or chronically ill veterinary patients is practical and provides information necessary for stabilization and treatment. Tissue magnesium concentrations may be assessed using nuclear magnetic resonance spectroscopy as well as through the application of fluorescent dye techniques. THERAPY Magnesium infusions may play a therapeutic role in reperfusion injury, myocardial ischemia, cerebral infarcts, systemic inflammatory response syndromes, tetanus, digitalis toxicity, bronchospasms, hypercoagulable states, and as an adjunct to specific anesthetic or analgesic protocols. Further veterinary studies are needed to establish the frequency and importance of magnesium disorders in animals and the potential benefit of magnesium infusions as a therapeutic adjunct to specific diseases. PROGNOSIS The prognosis for most patients with magnesium disorders is variable and largely dependent on the underlying cause of the disorder.
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Affiliation(s)
- Sarah Humphrey
- From the Animal Emergency Center and Specialty Services, Glendale, WI 52309
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6
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Vennemeyer JJ, Hopkins T, Hershcovitch M, Little KD, Hagen MC, Minteer D, Hom DB, Marra K, Pixley SK. Initial observations on using magnesium metal in peripheral nerve repair. J Biomater Appl 2014; 29:1145-54. [PMID: 25281648 DOI: 10.1177/0885328214553135] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Biodegradable magnesium metal filaments placed inside biodegradable nerve conduits might provide the physical guidance support needed to improve the rate and extent of regeneration of peripheral nerves across injury gaps. In this study, we examined basic issues of magnesium metal resorption and biocompatibility by repairing sub-critical size gap injuries (6 mm) in one sciatic nerve of 24 adult male Lewis rats. Separated nerve stumps were connected with poly(caprolactone) nerve conduits, with and without magnesium filaments (0.25 mm diameter, 10 mm length), with two different conduit filler substances (saline and keratin hydrogel). At 6 weeks after implantation, magnesium degradation was examined by micro-computed tomography and histological analyses. Magnesium degradation was significantly greater when the conduits were filled with an acidic keratin hydrogel than with saline (p < 0.05). But magnesium filaments in some animals remained intact for 6 weeks. Using histological and immunocytochemical analyses, good biocompatibility of the magnesium implants was observed at 6 weeks, as shown by good development of regenerating nerve mini-fascicles and only mild inflammation in tissues even after complete degradation of the magnesium. Nerve regeneration was not interrupted by complete magnesium degradation. An initial functional evaluation, determination of size recovery of the gastrocnemius muscle, showed a slight improvement due to magnesium with the saline but not the keratin filler, compared with respective control conduits without magnesium. These results suggest that magnesium filament implants have the potential to improve repair of injured peripheral nerve defects in this rodent model.
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Affiliation(s)
- J J Vennemeyer
- Department of Biomedical Engineering, University of Cincinnati, OH, USA
| | - T Hopkins
- Department of Molecular and Cellular Physiology, University of Cincinnati, OH, USA
| | - M Hershcovitch
- Department of Otolaryngology-Head & Neck Surgery, University of Cincinnati, OH, USA
| | - K D Little
- Department of Orthopaedic Surgery, University of Cincinnati, OH, USA
| | - M C Hagen
- Department of Pathology and Laboratory Medicine, University of Cincinnati, OH, USA
| | - D Minteer
- Department of Bioengineering, University of Pittsburgh, PA, USA
| | - D B Hom
- Division of Facial Plastic and Reconstructive Surgery, Department of Otolaryngology-Head & Neck Surgery and Dermatology, University of Cincinnati, OH, USA
| | - K Marra
- Department of Bioengineering and Department of Plastic Surgery, University of Pittsburgh, PA, USA
| | - S K Pixley
- Department of Molecular and Cellular Physiology, University of Cincinnati, OH, USA
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7
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Gold EM, Su D, López-Velázquez L, Haus DL, Perez H, Lacuesta GA, Anderson AJ, Cummings BJ. Functional assessment of long-term deficits in rodent models of traumatic brain injury. Regen Med 2014; 8:483-516. [PMID: 23826701 DOI: 10.2217/rme.13.41] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Traumatic brain injury (TBI) ranks as the leading cause of mortality and disability in the young population worldwide. The annual US incidence of TBI in the general population is estimated at 1.7 million per year, with an estimated financial burden in excess of US$75 billion a year in the USA alone. Despite the prevalence and cost of TBI to individuals and society, no treatments have passed clinical trial to clinical implementation. The rapid expansion of stem cell research and technology offers an alternative to traditional pharmacological approaches targeting acute neuroprotection. However, preclinical testing of these approaches depends on the selection and characterization of appropriate animal models. In this article we consider the underlying pathophysiology for the focal and diffuse TBI subtypes, discuss the existing preclinical TBI models and functional outcome tasks used for assessment of injury and recovery, identify criteria particular to preclinical animal models of TBI in which stem cell therapies can be tested for safety and efficacy, and review these criteria in the context of the existing TBI literature. We suggest that 2 months post-TBI is the minimum period needed to evaluate human cell transplant efficacy and safety. Comprehensive review of the published TBI literature revealed that only 32% of rodent TBI papers evaluated functional outcome ≥1 month post-TBI, and only 10% evaluated functional outcomes ≥2 months post-TBI. Not all published papers that evaluated functional deficits at a minimum of 2 months post-TBI reported deficits; hence, only 8.6% of overall TBI papers captured in this review demonstrated functional deficits at 2 months or more postinjury. A 2-month survival and assessment period would allow sufficient time for differentiation and integration of human neural stem cells with the host. Critically, while trophic effects might be observed at earlier time points, it will also be important to demonstrate the sustainability of such an effect, supporting the importance of an extended period of in vivo observation. Furthermore, regulatory bodies will likely require at least 6 months survival post-transplantation for assessment of toxicology/safety, particularly in the context of assessing cell abnormalities.
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Affiliation(s)
- Eric M Gold
- Sue & Bill Gross Stem Cell Research Center, University of California, Irvine 2030 Gross Hall, CA 92697-1705, USA
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8
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Blaylock RL, Maroon J. Natural plant products and extracts that reduce immunoexcitotoxicity-associated neurodegeneration and promote repair within the central nervous system. Surg Neurol Int 2012; 3:19. [PMID: 22439110 PMCID: PMC3307240 DOI: 10.4103/2152-7806.92935] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 01/11/2012] [Indexed: 12/14/2022] Open
Abstract
Our understanding of the pathophysiological and biochemical basis of a number of neurological disorders has increased enormously over the last three decades. Parallel with this growth of knowledge has been a clearer understanding of the mechanism by which a number of naturally occurring plant extracts, as well as whole plants, can affect these mechanisms so as to offer protection against injury and promote healing of neurological tissues. Curcumin, quercetin, green tea catechins, balcalein, and luteolin have been extensively studied, and they demonstrate important effects on cell signaling that go far beyond their antioxidant effects. Of particular interest is the effect of these compounds on immunoexcitotoxicity, which, the authors suggest, is a common mechanism in a number of neurological disorders. By suppressing or affecting microglial activation states as well as the excitotoxic cascade and inflammatory mediators, these compounds dramatically affect the pathophysiology of central nervous system disorders and promote the release and generation of neurotrophic factors essential for central nervous system healing. We discuss the various aspects of these processes and suggest future directions for study.
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Affiliation(s)
- Russell L Blaylock
- Theoretical Neurosciences, Department of Biology, Belhaven University, Jackson, MS 39157, USA
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9
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Wheaton P, Mathias JL, Vink R. Impact of pharmacological treatments on outcome in adult rodents after traumatic brain injury: a meta-analysis. J Psychopharmacol 2011; 25:1581-99. [PMID: 21300634 DOI: 10.1177/0269881110388331] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Pharmacological treatments have been widely investigated in pre-clinical animal trials to evaluate their usefulness in reducing cognitive, behavioural and motor problems after traumatic brain injury (TBI). However, the relative efficacy of these agents has yet to be evaluated, making it difficult to assess the strength of evidence for their use in a clinical population. A meta-analytic review of research (1980-2009) was therefore conducted to examine the impact of pharmacological treatments administered to adult male rodents after experimental TBI on cognitive, behavioural, and motor outcome. The PubMed and PsycInfo databases were searched using 35 terms. Weighted Cohen's d effect sizes, percent overlap, Fail-Safe N statistics and confidence intervals were calculated for each treatment. In total, 91 treatments were evaluated in 223 pre-clinical trials, comprising 5988 rodents. Treatments that were investigated by multiple studies and showed large and significant treatment effects were of greatest interest. Of the 16 treatments that were efficacious, six improved cognition, 10 improved motor function and no treatment improved behaviour (depression/anxiety, aggression, zoosocial behaviour). Treatment benefits were found across a range of TBI models. Drug dosage and treatment interval impacted on treatment effects.
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Affiliation(s)
- P Wheaton
- School of Psychology, University of Adelaide, Adelaide, Australia
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10
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Marklund N, Hillered L. Animal modelling of traumatic brain injury in preclinical drug development: where do we go from here? Br J Pharmacol 2011; 164:1207-29. [PMID: 21175576 PMCID: PMC3229758 DOI: 10.1111/j.1476-5381.2010.01163.x] [Citation(s) in RCA: 178] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 12/02/2010] [Accepted: 12/06/2010] [Indexed: 11/26/2022] Open
Abstract
Traumatic brain injury (TBI) is the leading cause of death and disability in young adults. Survivors of TBI frequently suffer from long-term personality changes and deficits in cognitive and motor performance, urgently calling for novel pharmacological treatment options. To date, all clinical trials evaluating neuroprotective compounds have failed in demonstrating clinical efficacy in cohorts of severely injured TBI patients. The purpose of the present review is to describe the utility of animal models of TBI for preclinical evaluation of pharmacological compounds. No single animal model can adequately mimic all aspects of human TBI owing to the heterogeneity of clinical TBI. To successfully develop compounds for clinical TBI, a thorough evaluation in several TBI models and injury severities is crucial. Additionally, brain pharmacokinetics and the time window must be carefully evaluated. Although the search for a single-compound, 'silver bullet' therapy is ongoing, a combination of drugs targeting various aspects of neuroprotection, neuroinflammation and regeneration may be needed. In summary, finding drugs and prove clinical efficacy in TBI is a major challenge ahead for the research community and the drug industry. For a successful translation of basic science knowledge to the clinic to occur we believe that a further refinement of animal models and functional outcome methods is important. In the clinical setting, improved patient classification, more homogenous patient cohorts in clinical trials, standardized treatment strategies, improved central nervous system drug delivery systems and monitoring of target drug levels and drug effects is warranted.
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Affiliation(s)
- Niklas Marklund
- Department of Neuroscience, Neurosurgery, Uppsala University, Uppsala University Hospital, Uppsala, Sweden.
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11
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Sen AP, Gulati A. Use of magnesium in traumatic brain injury. Neurotherapeutics 2010; 7:91-9. [PMID: 20129501 PMCID: PMC5084116 DOI: 10.1016/j.nurt.2009.10.014] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Revised: 10/23/2009] [Accepted: 10/26/2009] [Indexed: 11/30/2022] Open
Abstract
Depletion of magnesium is observed in animal brain and in human blood after brain injury. Treatment with magnesium attenuates the pathological and behavioral changes in rats with brain injury; however, the therapeutic effect of magnesium has not been consistently observed in humans with traumatic brain injury (TBI). Secondary brain insults are observed in patients with brain injury, which adversely affect clinical outcome. Systemic administration studies in rats have shown that magnesium enters the brain; however, inducing hypermagnesemia in humans did not concomitantly increase magnesium levels in the CSF. We hypothesize that the neuroprotective effects of magnesium in TBI patients could be observed by increasing its brain bioavailability with mannitol. Here, we review the role of magnesium in brain injury, preclinical studies in brain injury, clinical safety and efficacy studies in TBI patients, brain bioavailability studies in rat, and pharmacokinetic studies in humans with brain injury. Neurodegeneration after brain injury involves multiple biochemical pathways. Treatment with a single agent has often resulted in poor efficacy at a safe dose or toxicity at a therapeutic dose. A successful neuroprotective therapy needs to be aimed at homeostatic control of these pathways with multiple agents. Other pharmacological agents, such as dexanabinol and progesterone, and physiological interventions, with hypothermia and hyperoxia, have been studied for the treatment of brain injury. Treatment with magnesium and hypothermia has shown favorable outcome in rats with cerebral ischemia. We conclude that coadministration of magnesium and mannitol with pharmacological and physiological agents could be an effective neuroprotective regimen for the treatment of TBI.
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12
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Tzen JT, Jinn TR, Chen YC, Li FY, Cheng FC, Shi LS, She HK, Chen BC, Hsieh V, Tu ML. Magnesium lithospermate B possesses inhibitory activity on Na+,K+-ATPase and neuroprotective effects against ischemic stroke. Acta Pharmacol Sin 2007; 28:609-15. [PMID: 17439716 DOI: 10.1111/j.1745-7254.2007.00544.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
AIM To examine if magnesium lithospermate B (MLB) extracted from Danshen, the dried roots of Salvia miltiorrhiza, may act as an active component responsible for the cardiac therapeutic effect of this traditional Chinese herb via the same molecular mechanism triggered by cardiac glycosides, such as ouabain and digoxin. Moreover, we wanted to test if MLB may provide neuroprotection against ischemic stroke as observed for cardiac glycosides. METHODS Similarity in the chemical structure and molecular configuration between MLB and ouabain was analyzed. The inhibition potency of MLB and ouabain on Na( +),K( +) -ATPase activity of a commercial product, as well as in purified membrane fractions from rat brain and heart tissues, was examined and compared. Neuroprotective effect of MLB against ischemic stroke was also evaluated using a cortical brain slice-based assay model. RESULTS Dose-dependent inhibition on the commercial Na( +),K( +)-ATPase equivalent to that for ouabain was observed for MLB of approximately half dosage by weight. This relative potency of ouabain and MLB was also observed for their inhibition on Na( +),K( +)-ATPase activity of plasma membrane purified from rat tissues, although these 2 inhibitors exhibited somewhat lower competence in these crude extracts. In ischemic gerbil brains, post-treatment with MLB significantly reduced the infarct size, visualized by 2,3,5-triphenyltetrazolium chloride staining, by approximately 55% when compared with the control group. CONCLUSION These results evidently suggest that the cardiac therapeutic effect of Danshen should be at least partly attributed to the effective inhibition of Na( +),K( +)-ATPase by MLB, and that MLB provides anti-ischemic neuroprotection in gerbils subjected to focal ischemia and reperfusion.
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Affiliation(s)
- Jason Tc Tzen
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, Taiwan 402 China.
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13
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Temkin NR, Anderson GD, Winn HR, Ellenbogen RG, Britz GW, Schuster J, Lucas T, Newell DW, Mansfield PN, Machamer JE, Barber J, Dikmen SS. Magnesium sulfate for neuroprotection after traumatic brain injury: a randomised controlled trial. Lancet Neurol 2007; 6:29-38. [PMID: 17166799 DOI: 10.1016/s1474-4422(06)70630-5] [Citation(s) in RCA: 187] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
BACKGROUND Traumatic brain injuries represent an important and costly health problem. Supplemental magnesium positively affects many of the processes involved in secondary injury after traumatic brain injury and consistently improves outcome in animal models. We aimed to test whether treatment with magnesium favourably affects outcome in head-injured patients. METHODS In a double-blind trial, 499 patients aged 14 years or older admitted to a level 1 regional trauma centre between August, 1998, and October, 2004, with moderate or severe traumatic brain injury were randomly assigned one of two doses of magnesium or placebo within 8 h of injury and continuing for 5 days. Magnesium doses were targeted to achieve serum magnesium ranges of 1.0-1.85 mmol/L or 1.25-2.5 mmol/L. The primary outcome was a composite of mortality, seizures, functional measures, and neuropsychological tests assessed up to 6 months after injury. Analyses were done according to the intention-to-treat principle. This trial is registered with , number . FINDINGS Magnesium showed no significant positive effect on the composite primary outcome measure at the higher dose (mean=55 average percentile ranking on magnesium vs 52 on placebo, 95% CI for difference -7 to 14; p=0.70). Those randomly assigned magnesium at the lower dose did significantly worse than those assigned placebo (48 vs 54, 95% CI -10.5 to -2; p=0.007). Furthermore, there was higher mortality with the higher magnesium dose than with placebo. Other major medical complications were similar between groups, except for a slight excess of pulmonary oedema and respiratory failure in the lower magnesium target group. No subgroups were identified in which magnesium had a significantly positive effect. INTERPRETATION Continuous infusions of magnesium for 5 days given to patients within 8 h of moderate or severe traumatic brain injury were not neuroprotective and might even have a negative effect in the treatment of significant head injury.
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Affiliation(s)
- Nancy R Temkin
- Department of Neurological Surgery, University of Washington, Seattle, USA.
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14
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Khashaba MT, Shouman BO, Shaltout AA, Al-Marsafawy HM, Abdel-Aziz MM, Patel K, Aly H. Excitatory amino acids and magnesium sulfate in neonatal asphyxia. Brain Dev 2006; 28:375-9. [PMID: 16545929 DOI: 10.1016/j.braindev.2005.11.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2005] [Revised: 11/24/2005] [Accepted: 11/28/2005] [Indexed: 11/22/2022]
Abstract
The excitatory amino acids (EAA); glutamate and aspartate are released into the cerebrospinal fluids (CSF) of asphyxiated newborns. The objectives of this study were: (a) to examine the relation of the concentration of EAA in the CSF with the degree of brain injury, (b) To determine the time of the release of these EAA into the CSF, and (c) to detect the effect of magnesium sulfate (MgSO(4)) on their levels. DESIGNS AND METHODS. A randomized controlled trial was conducted on 47 full term asphyxiated newborns. Twenty three infants received an intravenous 10% solution of MgSO(4) at a dose of 250 mg/kg within the first 24h of life while the other 24 newborns received isotonic saline (0.9%) of an equal volume. Levels of glutamate and aspartate were measured before and 72 h after giving the trial solution. Results. In the study population (n=47) both glutamate and aspartate were significantly elevated in infants with higher grades of HIE compared to those with lower grades (P=0.013 and 0.031, respectively). Compared to baseline level, glutamate decreased significantly over time in placebo group (-8.28+/-14.26, P=0.025) and in MgSO(4) group (-14.39+/-18.72, P=0.005). Glutamate concentration did not differ between groups when measured at baseline (29.26+/-16.31 vs. 31.27+/-22.62, P=0.82) and at 72 h (19.28+/-15.63 vs. 19.6+/-16.54, P=0.87). The change in aspartate concentration over time was not significant in placebo group (-0.45+/-1.96, P=0.34) or in MgSO(4) group (-0.7+/-3.19, P=0.37). Aspartate did not differ between groups when measured at baseline (3.52+/-2.4 vs. 3.92+/-2.59, P=0.49) or at 72 h (2.79+/-1.24 vs. 3.05+/-2.48, P=0.92). Conclusions. The EAA; glutamate and aspartate are released in the CSF of asphyxiated newborns immediately after birth and declined by 72 h. Their initial concentrations correlated with the severity of HIE. Postnatal administration of MgSO(4) did not alter the levels of these 2 EAA.
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Affiliation(s)
- Mohamed T Khashaba
- Department of Pediatrics, Mansoura University Children's Hospital, Mansoura, Egypt
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15
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Abstract
Epilepsy is a major unfavorable long-term consequence of traumatic brain injury (TBI). Moreover, TBI is one of the most important predisposing factors for the development of epilepsy, particularly in young adults. Understanding the molecular and cellular cascades that lead to the development of post-traumatic epilepsy (PTE) is key for preventing its development or modifying the disease process in such a way that epilepsy, if it develops, is milder and easier-to-treat. Tissue from TBI patients undergoing epileptogenesis is not available for such studies, which underscores the importance of developing clinically relevant animal models of PTE. The goal of this review is to (1) provide a description of PTE in humans, which is critical for the development of clinically relevant models of PTE, (2) review the characteristics of currently available PTE models, and (3) provide suggestions for the development of future models of PTE based on our current understanding of the mechanisms of TBI and epilepsy. The development of clinically relevant models of PTE is critical to advance our understanding of the mechanisms of post-traumatic epileptogenesis and epilepsy, as well as for producing breakthroughs in the development and testing of novel antiepileptogenic treatments.
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Affiliation(s)
- Asla Pitkänen
- Epilepsy Research Laboratory, AI Virtanen Institute for Molecular Sciences, University of Kuopio, Kuopio, Finland.
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16
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Iwata A, Browne KD, Chen XH, Yuguchi T, Smith DH. Traumatic brain injury induces biphasic upregulation of ApoE and ApoJ protein in rats. J Neurosci Res 2006; 82:103-14. [PMID: 16118797 DOI: 10.1002/jnr.20607] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Apolipoproteins play an important role in cell repair and have been found to increase shortly after traumatic brain injury (TBI). In addition, apolipoproteins reduce amyloid-beta (Abeta) accumulation in models of Alzheimer's disease. Considering that TBI induces progressive neurodegeneration including Abeta accumulation, we explored potential long-term changes in the gene and protein expression of apolipoproteins E and J (ApoE and J) over 6 months after injury. Anesthetized male Sprague-Dawley rats were subjected to parasagittal fluid-percussion brain injury and their brains were evaluated at 2, 4, 7, 14 days, and 1 and 6 months after TBI. In situ hybridization, Western blot, and immunohistochemical analysis demonstrated that although there was a prolonged upregulation in both the gene expression and protein concentration of ApoE and J after injury, these responses were uncoupled. Upregulation of ApoE and J mRNA expression lasted from 4 days to 1 month after injury. In contrast, a biphasic increase in protein concentration and number of immunoreactive cells for ApoE and ApoJ was observed, initially peaking at 2 days (i.e., before increased mRNA expression), returning to baseline by 2 weeks and then gradually increasing through 6 months postinjury. In addition, ApoE and J were found to colocalize with Abeta accumulation in neurons and astrocytes at 1-6 months after injury. Collectively, these data suggest that ApoE and J play a role in the acute sequelae of brain trauma and reemerge long after the initial insult, potentially to modulate progressive neurodegenerative changes.
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Affiliation(s)
- Akira Iwata
- Department of Neurosurgery, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-6316, USA
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