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Skalska M, Myśliwiec A, Michalak A, Chrzanowski J, Lejk A, Jastrzębska J, Radzimiński Ł, Lopez-Sanchez GF, Myśliwiec K, Jastrzębski Z, Weiss K, Knechtle B. Metabolic control level and glucose variability in adolescents with type 1 diabetes during low and high-intensity exercise. Eur Rev Med Pharmacol Sci 2024; 28:1987-1997. [PMID: 38497881 DOI: 10.26355/eurrev_202403_35613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
OBJECTIVE The main purpose of this study was to characterize the determinants of metabolic changes in young type 1 diabetes (T1DM) and to determine glycemic variability during low and high-intensity exercise. PATIENTS AND METHODS 20 young male T1DM patients were divided into two subgroups characterized by levels of glycated hemoglobin (HbA1c): HbA1c<7.3% (better HbA1c subgroup, n=10) and with levels HbA1c>7.3% (worse HbA1c subgroup, n=10). All participants performed a maximal oxygen uptake test and two efforts of various intensities (45 minutes of aerobic exercise and 30 minutes of mixed aerobic-anaerobic intensity exercise). Continuous glucose monitors (CGM) were used to control the glucose concentration. RESULTS Changes in biomarkers describing the metabolic response were similar in both groups. A comparison of applied efforts exhibited that maximal capacity effort resulted in the highest values of blood glucose (BG) at the end (150.9-160.6 mg/dl) and 1 hour after the exercise (140.2-161.3 mg/dl). BG concentration before, during, 1 hour, and 24 hours after each exercise was insignificantly higher in the worse Hb1Ac group. CONCLUSIONS HbA1c levels are insufficient to confirm whether the applied effort is performed in acceptable glycemic values. The CGM monitors allow for precise control of BG variations and accurate planning of physical activity by adjusting the insulin and carbohydrate consumption dose.
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Affiliation(s)
- M Skalska
- Department of Pediatrics, Diabetology and Endocrinology, Gdansk Medical University, Gdansk, Poland.
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Michalak A, Wdowikowska A, Janicka M. Plant Plasma Membrane Proton Pump: One Protein with Multiple Functions. Cells 2022; 11:cells11244052. [PMID: 36552816 PMCID: PMC9777500 DOI: 10.3390/cells11244052] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/13/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
In plants, the plasma membrane proton pump (PM H+-ATPase) regulates numerous transport-dependent processes such as growth, development, basic physiology, and adaptation to environmental conditions. This review explores the multifunctionality of this enzyme in plant cells. The abundance of several PM H+-ATPase isogenes and their pivotal role in energizing transport in plants have been connected to the phenomena of pleiotropy. The multifunctionality of PM H+-ATPase is a focal point of numerous studies unraveling the molecular mechanisms of plant adaptation to adverse environmental conditions. Furthermore, PM H+-ATPase is a key element in plant defense mechanisms against pathogen attack; however, it also functions as a target for pathogens that enable plant tissue invasion. Here, we provide an extensive review of the PM H+-ATPase as a multitasking protein in plants. We focus on the results of recent studies concerning PM H+-ATPase and its role in plant growth, physiology, and pathogenesis.
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Shabana Z, Michalak A, Garcia-Vite T, Mann A, Grove V, Conway T, Tsigarides J, Gill N, Laycock S, Johannsen L, Lazar A. Effects of sleep restriction and time of the day on balance control in healthy older men and women. Sleep Med 2022. [DOI: 10.1016/j.sleep.2022.05.482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Biala G, Pekala K, Boguszewska-Czubara A, Michalak A, Kruk-Slomka M, Grot K, Budzynska B. Behavioral and Biochemical Impact of Chronic Unpredictable Mild Stress on the Acquisition of Nicotine Conditioned Place Preference in Rats. Mol Neurobiol 2017; 55:3270-3289. [PMID: 28484990 PMCID: PMC5842504 DOI: 10.1007/s12035-017-0585-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 04/27/2017] [Indexed: 01/20/2023]
Abstract
Addiction is a chronic psychiatric disease which represents a global problem, and stress can increase drug addiction and relapse. Taking into account frequent concomitance of nicotine dependence and stress, the purpose of the present study was to assess behavioral and biochemical effects of chronic unpredictable mild stress (CUMS) exposure on nicotine reward in rats measured in the conditioned place preference (CPP) paradigm. Rats were submitted to the CUMS for 3 weeks and conditioned with nicotine (0.175 mg/kg) for 2 or 3 days. Our results revealed that only CUMS-exposed animals exhibited the CPP after 2 days of conditioning indicating that stressed rats were more sensitive to the rewarding properties of nicotine and that chronic stress exacerbates nicotine preference. Administration of metyrapone (50 mg/kg), a glucocorticosteroid antagonist, and imipramine (15 mg/kg), an antidepressant, abolished nicotine CPP in stressed rats after 2 days of conditioning. The biochemical experiments showed increased markers of oxidative stress after nicotine conditioning for 2 and 3 days, while the CUMS further potentiated pro-oxidative effects of nicotine. Moreover, metyrapone reversed oxidative changes caused by stress and nicotine, while imipramine was not able to overwhelm nicotine- and stress-induced oxidative damages; however, it could exert antioxidant effect if administered repeatedly. The results suggest that recent exposure to a stressor may augment the rewarding effects of nicotine through anhedonia- and stress-related mechanisms. Our study contributes to the understanding of behavioral and biochemical stress-induced modification of the rewarding effects of nicotine on the basis of the development of nicotine dependence.
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Affiliation(s)
- G Biala
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodzki 4A Street, 20-093, Lublin, Poland.
| | - K Pekala
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodzki 4A Street, 20-093, Lublin, Poland
| | - A Boguszewska-Czubara
- Department of Medical Chemistry, Medical University of Lublin, Chodzki 4A Street, 20-093, Lublin, Poland
| | - A Michalak
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodzki 4A Street, 20-093, Lublin, Poland
| | - M Kruk-Slomka
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodzki 4A Street, 20-093, Lublin, Poland
| | - K Grot
- Department of Medical Chemistry, Medical University of Lublin, Chodzki 4A Street, 20-093, Lublin, Poland
| | - B Budzynska
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodzki 4A Street, 20-093, Lublin, Poland
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Biala G, Pekala K, Boguszewska-Czubara A, Michalak A, Kruk-Slomka M, Budzynska B. Behavioral and Biochemical Interaction Between Nicotine and Chronic Unpredictable Mild Stress in Mice. Mol Neurobiol 2016; 54:904-921. [PMID: 26780460 PMCID: PMC5310564 DOI: 10.1007/s12035-016-9701-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 01/05/2016] [Indexed: 11/24/2022]
Abstract
Nicotine, the main component of tobacco smoke, exerts influence on mood, and contributes to physical and psychological dependence. Taking into account frequent concomitance of nicotine abuse and stress, we aimed to research behavioral and biochemical effects associated with nicotine administration in combination with chronic unpredictable mild stress (CUMS). Mice were submitted to the procedure of CUMS for 4 weeks, 2 h per day. Our results revealed that CUMS-exposed animals exhibited behavioral alteration like anxiety disorders in the elevated plus maze (EPM) test, the disturbances in memory in the passive avoidance (PA) test and depressive effects in the forced swim test (FST). Moreover, nicotine (0.05–0.5 mg/kg), after an acute or subchronic administration decreased stress-induced depression- and anxiety-like effect as well as memory deficit. Administration of metyrapone (50 mg/kg), a glucocorticosteroid antagonist, alleviated the depressive effect induced by the CUMS. The biochemical experiments showed decreased values of the total antioxidant status (TAS), activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) with simultaneously increased in malondialdehyde (MDA) concentration in mice submitted to the CUMS. The same effects were observed after an acute and subchronic nicotine administration within all examined brain structures (i.e., hippocampus, cortex, and cerebellum) and in the whole brain in non-stressed and stressed mice confirming pro-oxidative effect of nicotine. Our study contributes to the understanding of behavioral and biochemical mechanisms involved in stress-induced disorders such as depression, anxiety and memory disturbances as well as dual nicotine-stress interactions on the basis of the development of nicotine dependence.
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Affiliation(s)
- G Biala
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodzki 4A Street, 20-093, Lublin, Poland.
| | - K Pekala
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodzki 4A Street, 20-093, Lublin, Poland
| | - A Boguszewska-Czubara
- Department of Medical Chemistry, Medical University of Lublin, Chodzki 4A Street, 20-093, Lublin, Poland
| | - A Michalak
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodzki 4A Street, 20-093, Lublin, Poland
| | - M Kruk-Slomka
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodzki 4A Street, 20-093, Lublin, Poland
| | - B Budzynska
- Department of Pharmacology and Pharmacodynamics, Medical University of Lublin, Chodzki 4A Street, 20-093, Lublin, Poland
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Kao R, Rajagopalan A, Beckett A, Beckett A, Rex R, Shah S, Waddell J, Boitano M, Faidi S, Babatunde O, Lawson F, Grant A, Sudarshan M, Sudarshan M, Takashashi M, Waggott M, Lampron J, Post A, Beale E, Bobrovitz N, Zakrison T, Smith A, Bawazeer M, Evans C, Leeper T, Kagedan D, Grenier T, Rezendo-Neto J, Roberts D, Roberts D, Stark P, Berg R, Mehta S, Gardner P, Moore L, Vassilyadi M, Moore L, Moore L, Hoshizaki B, Rezende-Neto J, Slaba I, Ramesh A, Grigorovich A, Parry N, Pajak C, Rosenbloom B, Grunfeld A, van Heest R, Fernandes J, Doucet J, Schooler S, Ali J, Klassen B, Santana M, McFarlan A, Ball C, Blackmore C, Rezende-Neto J, Kidane B, Hicks C, Brennan M, Brennan M, Harrington A, Sorvari A, Stewart TC, Biegler N, Chaubey V, Tsang B, Benjamin S, Hogan A, Fraser J, Martin M, Bridge J, Faidi S, Waligora M, Hsiao M, Sharma S, Sankarankutty A, Mckee J, Mckee J, Mckee J, Snider C, Szpakowski J, Brown R, Shah S, Shiu M, Chen M, Bell N, Besserer F, Bell N, Trudeau MO, Alhabboubi M, Rezende-Neto J, Rizoli S, Hill A, Joseph B, Lawless B, Jiao X, Xenocostas A, Rui T, Parry N, Driman D, Martin C, Stewart TC, Walsh J, Parry N, Merritt N, Elster E, Tien H, Phillips L, Bratu I, Nascimento B, Pinto R, Callum J, Tien H, Rizoli S, McMullan J, McGlasson R, Mahomed N, Flannery J, Bir C, Baillie F, Coates A, Asiri S, Foster P, Baillie F, Bhandari M, Phillips L, Bratu I, Schuurman N, Oliver L, Nathens A, Yazdani A, Alhabboubi M, St. Louis E, Tan X, Fata P, Deckelbaum D, Chughtai T, Razek T, Khwaja K, St. Louis E, Alhabboubi M, Tan X, Fata P, Deckelbaum D, Chughtai T, Razek T, Khwaja K, Takada M, Sawano M, Ito H, Tsutsumi H, Keenan A, Waggott M, Hoshizaki B, Brien S, Gilchrist M, Janis J, Phelan H, Minei J, Santana M, Stelfox H, McCredie V, Leung E, Garcia G, Rizoli S, Nathens A, Dixon E, Niven D, Kirkpatrick A, Feliciano D, D’Amours S, Ball C, Ahmed N, Izadi H, McFarlan A, Nathens A, Pavenski K, Nathens A, Bridge J, Tallon J, Leeper W, Vogt K, Stewart TC, Gray D, Parry N, Ameer A, Alhabboubi M, Alzaid S, Deckelbaum D, Fata P, Khwaja K, Razek T, Deckelbaum D, Drudi L, Boulva K, Rodrigue N, Khwaja K, Chughtai T, Fata P, Razek T, Rizoli S, Carreiro P, Lisboa T, Winter P, Ribeiro E, Cunha-Melo J, Andrade M, Zygun D, Grendar J, Ball C, Robertson H, Ouellet JF, Cheatham M, Kirkpatrick A, Ball C, Ouellet JF, McBeth P, Kirkpatrick A, Dixon E, Groff P, Inaba K, Okoye O, Pasley J, Demetriades D, Al-Harthi F, Cheng A, Lalani A, Mikrogianakis A, Cayne S, Knittel-Keren D, Gomez M, Stelfox H, Turgeon A, Lapointe J, Bourgeois G, Karton C, Rousseau P, Hoshizaki B, Stelfox H, Turgeon A, Bourgeois G, Lapointe J, Stelfox H, Turgeon A, Bourgeois G, Lapointe J, Rousseau P, Braga B, Faleiro R, Magaldi M, Cardoso G, Lozada W, Duarte L, Rizoli S, Ball C, Oddone-Paolucci E, Doig C, Kortbeek J, Gomez M, Fish J, Leach L, Leelapattana P, Fleming J, Bailey C, Nolan B, DeMestral C, McFarlan A, Zakirova R, Nathens A, Dabbs J, Duff D, Michalak A, Mitchell L, Nathens A, Singh M, Topolovec-Vranic J, Tymianski D, Yetman L, Canzian S, MacPhail I, Constable L, van Heest R, Tam A, Mahadevan P, Kim D, Bansal V, Casola G, Coimbra R, Gladwin C, Misra M, Kumar S, Gautam S, Sorvari A, Blackwood B, Coates A, Baillie F, Stelfox H, Nathens A, Wong C, Straus S, Haas B, Lenartowicz M, Parkovnick M, Parry N, Inaba K, Dixon E, Salim A, Pasley J, Kirkpatrick A, Ouellet JF, Niven D, Kirkpatrick A, Ball C, Neto C, Nogueira G, Fernandes M, Almeida T, de Abreu EMS, Rizoli S, Abrantes W, Taranto V, Parry N, Forbes T, Knight H, Keenan A, Yoxon H, Macpherson A, Bridge J, Topolovec-Vranic J, Mauceri J, Butorac E, Ahmed N, Holmes J, Gilliland J, Healy M, Tanner D, Polgar D, Fraser D, McBeth P, Crawford I, Tiruta C, Ball C, Kirkpatrick A, Roberts D, Ferri M, Bobrovitz N, Khandwala F, Stelfox H, Widder S, Mckee J, Hogan A, Benjamin S, Atkinson P, Benjamin S, Watson I, Hogan A, Benjamin S, Woodford S, Jaramillo DG, Nathens A, Alonazi N, Coates A, Baillie F, Zhang C, McFarlan A, Sorvari A, Chalklin K, Canzian S, Nathens A, DeMestral C, Hill A, Langer J, Nascimento B, Alababtain I, Fung SY, Passos E, Luz L, Brnjac E, Pinto R, Rizoli S, Widder S, Widder S, Widder S, Nathens A, Van Heest R, Constable L, Mancini F, Heidary B, Bell N, Appleton L, Hennecke P, Taunton J, Khwaja K, O’Connor M, Hameed M, Garraway N, Simons R, Evans D, Taulu T, Quinn L, Kuipers D, Rizoli S, Rogers C, Geerts W, Rhind S, Rizoli S, George K, Quinn L, Babcock C, Hameed M, Simons R, Caron N, Hameed M, Simons R, Prévost F, Razek T, Khwaja K, Sudarshan M, Razek T, Fata P, Deckelbaum D, Khwaja K, de Abreu EMS, Neto C, Almeida T, Pastore M, Taranto V, Fernandes M, Rizoli S, Nascimento B, Sankarankutty A, Pinto R, Callum J, Tremblay L, Tien H, Fowler R, Pinto R, Nathens A, Sadoun M, Harris J, Friese R, Kulvantunyou N, O’Keeffe T, Wynne J, Tang A, Green D, Rhee P, Trpkovski J, Blount V. Trauma Association of Canada Annual Scientific Meeting abstractsErythroopoietin resuscitated with normal saline, Ringer’s lactate and 7.5% hypertonic saline reduces small intestine injury in a hemorrhagic shock and resuscitation rat model.Analgesia in the management of pediatric trauma in the resuscitative phase: the role of the trauma centre.Multidisciplinary trauma team care in Kandahar, Afghanistan: current injury patterns and care practices.Does computed tomography for penetrating renal injury reduce renal exploration? An 8-year review at a Canadian level 1 trauma centre.The other side of pediatric trauma: violence and intent injury.Upregulation of activated protein C leads to factor V deficiency in early trauma coagulopathy.A provincial integrated model of improved care for patients following hip fracture.Sports concussion: an Olympic boxing model comparing sex with biomechanics and traumatic brain injury.A multifaceted quality improvement strategy to optimize monitoring and management of delirium in trauma patients: results of a clinician survey.Risk factors for severe all-terrain vehicle injuries in Alberta.Evaluating potential spatial access to trauma centre care by severely injured patients.Incidence of brain injury in facial fractures.Surgical outcomes and the acute care surgery service.The acute care general surgery population and prognostic factors for morbidity and mortality.Disaster preparedness of trauma.What would you like to know and how can we help you? Assessing the needs of regional trauma centres.Posttraumatic stress disorder screening for trauma patients at a level 1 trauma centre.Physical and finite element model reconstruction of a subdural hematoma event.Abdominal wall reconstruction in the trauma patient with an open abdomen.Development and pilot testing of a survey to measure patient and family experiences with injury care.Occult shock in trauma: What are Canadian traumatologists missing?Timeliness in obtaining emergent percutaneous procedures for the severely injured patient: How long is too long?97% of massive transfusion protocol activations do not include a complete hemorrhage panel.Trauma systems in Canada: What system components facilitate access to definitive care?The role of trauma team leaders in missed injuries: Does specialty matter?The adverse consequences of dabigatran among trauma and acute surgical patients.A descriptive study of bicycle helmet use in Montréal.Factor XIII, desmopressin and permissive hypotension enhance clot formation compared with normotensive resuscitation: uncontrolled hemorrhagic shock model.Negative pressure wound therapy for critically ill adults with open abdominal wounds: a systematic review.The “weekend warrior:” Fact or fiction for major trauma?Canadian injury preventon curriculum: a means to promote injury prevention.Penetrating splenic trauma: Safe for nonoperative management?The pediatric advanced trauma life support course: a national initiative.The effectiveness of a psycho-educational program among outpatients with burns or complex trauma.Trauma centre performance indicators for nonfatal outcomes: a scoping review.The evaluation of short track speed skating helmet performance.Complication rates as a trauma care performance indicator: a systematic review.Unplanned readmission following admission for traumatic injury: When, where and why?Reconstructions of concussive impacts in ice hockey.How does head CT correlate with ICP monitoring and impact monitoring discontinuation in trauma patients with a Marshall CT score of I–II?Impact of massive transfusion protocol and exclusion of plasma products from female donors on outcome of trauma patients in Calgary region of Alberta Health Services.Primary impact arthrodesis for a neglected open Weber B ankle fracture dislocation.Impact of depression on neuropsychological functioning in electrical injury patients.Predicting the need for tracheostomy in patients with cervical spinal cord injury.Predicting crumping during computed tomography imaging using base deficit.Feasibility of using telehomecare technology to support patients with an acquired brain injury and family care-givers.Program changes impact the outcomes of severely injured patients.Do trauma performance indicators accurately reflect changes in a maturing trauma program?One-stop falls prevention information for clinicians: a multidisciplinary interactive algorithm for the prevention of falls in older adults.Use of focused assessment with sonography for trauma (FAST) for combat casualties in forward facilities.Alberta All-terrain Vehicle Working Group: a call to action.Observations and potential role for the rural trauma team development course (RTTDC) in India.An electronic strategy to facilitate information-sharing among trauma team leaders.Development of quality indicators of trauma care by a consensus panel.An evaluation of a proactive geriatric trauma consultation service.Celebrity injury-related deaths: Is a gangster rapper really gangsta?Prevention of delirium in trauma patients: Are we giving thiamine prophylaxis a fair chance?Intra-abdominal injury in patients who sustain more than one gunshot wound to the abdomen: Should non-operative management be used?Retrospective review of blunt thoracic aortic injury management according to current treatment recommendations.Telemedicine for trauma resuscitation: developing a regional system to improve access to expert trauma care in Ontario.Comparing trauma quality indicator data between a pediatric and an adult trauma hospital.Using local injury data to influence injury prevention priorities.Systems saving lives: a structured review of pediatric trauma systems.What do students think of the St. Michael’s Hospital ThinkFirst Injury Prevention Strategy for Youth?An evidence-based method for targeting a shaken baby syndrome prevention media campaign.The virtual mentor: cost-effective, nurse-practitioner performed, telementored lung sonography with remote physician guidance.Quality indicators used by teaching versus nonteaching international trauma centres.Compliance to advanced trauma life support protocols in adult trauma patients in the acute setting.Closing the quality improvement loop: a collaborative approach.National Trauma Registry: “collecting” it all in New Brunswick.Does delay to initial reduction attempt affect success rates for anterior shoulder dislocation (pilot study)?Use of multidisciplinary, multi-site morbidity and mortality rounds in a provincial trauma system.Caring about trauma care: public awareness, knowledge and perceptions.Assessing the quality of admission dictation at a level 1 trauma centre.Trauma trends in older adults: a decade in review.Blunt splenic injury in patients with hereditary spherocytosis: a population-based analysis.Analysis of trauma team activation in severe head injury: an institutional experience.ROTEM results correlate with fresh frozen plasma transfusion in trauma patients.10-year trend of assault in Alberta.10-year trend in alcohol use in major trauma in Alberta.10-year trend in major trauma injury related to motorcycles compared with all-terrain vehicles in Alberta.Referral to a community program for youth injured by violence: a feasibility study.New impaired driving laws impact on the trauma population at level 1 and 3 trauma centres in British Columbia, Canada.A validation study of the mobile medical unit/polyclinic team training for the Vancouver 2010 Winter Games.Inferior vena cava filter use in major trauma: the Sunny-brook experience, 2000–2011.Relevance of cellular microparticles in trauma-induced coagulopathy: a systemic review.Improving quality through trauma centre collaboratives.Predictors of acute stress response in adult polytrauma patients following injury.Patterns of outdoor recreational injury in northern British Columbia.Risk factors for loss-to-follow up among trauma patients include functional, socio-economic, and geographic determinants: Would mandating opt-out consent strategies minimize these risks?Med-evacs and mortality rates for trauma from Inukjuak, Nunavik, Quebec.Review of open abdomens in McGill University Health Centre.Are surgical interventions for trauma associated with the development of posttraumatic retained hemothorax and empyema?A major step in understanding the mechanisms of traumatic coagulopathy: the possible role of thrombin activatable fibrinolysis inhibitor.Access to trauma centre care for patients with major trauma.Repeat head computed tomography in anticoagulated traumatic brain injury patients: still warranted.Improving trauma system governance. Can J Surg 2012. [DOI: 10.1503/cjs.006312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Michalak A, Ziegler T. Modeling ethylene and propylene homopolymerization by late-transition-metal catalysts: A combined quantum mechanical and stochastic approach. Kinet Catal 2006. [DOI: 10.1134/s0023158406020248] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Abstract
UNLABELLED Overt hyperthyroidism and hypothyroidism exert a major effect on cardiac function and on ECG. The influence of subclinical hyperthyroidism on the circulatory system is still under debate. Few studies examined the effect of thyroid hormones on ventricular repolarization measured by corrected QT interval (QTc). Longer QTc is associated with increased risk of arrhythmia and cardiac mortality. The aim of this study was to examine the influence of subclinical hyperthyroidism on ventricular repolarization measured by corrected QTc in a standard 12-lead electrocardiogram. The examined group consisted of thirty-two patients with subclinical hyperthyroidism; the controls were thirty-nine healthy individuals. In the group with subclinical hyperthyroidism, we observed a significant increase in heart rate (80.3 +/- 10.59 vs. 73.7 +/- 11.37 bpm, p < 0.05). The mean corrected QTc was 0.434 +/- 0.0207 seconds and 0.414 +/- 0.0208 in the examined groups and in controls, respectively (p < 0.001). QTc did not correlate with free thyroxin concentrations (p = 0.5084). CONCLUSION Corrected QT intervals were significantly longer in patients with subclinical hyperthyroidism.
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Affiliation(s)
- M Owecki
- Department of Endocrinology, Metabolism and Internal Medicine, Poznan University of Medical Sciences, Poznań, Poland.
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Komisarek J, Szyda J, Michalak A, Dorynek Z. Impact of leptin gene polymorphisms on breeding
value for milk production traits in cattle. J Anim Feed Sci 2005. [DOI: 10.22358/jafs/67042/2005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Michalak A, Ziegler T. DFT studies on the copolymerization of alpha-olefins with polar monomers: ethylene-methyl acrylate copolymerization catalyzed by a Pd-based diimine catalyst. J Am Chem Soc 2001; 123:12266-78. [PMID: 11734027 DOI: 10.1021/ja010876l] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Gradient-corrected density functional theory has been used to study the elementary reactions for the copolymerization of ethylene with methyl acrylate catalyzed by Pd-based diimine catalysts, modeled by the generic complex N(wedge)N-Pd(n-C(3)H(7))(+), with N(wedge)N = -NHCHCHNH-. The steric effects in the real systems are discussed on the basis of the calculations for the catalyst with N(wedge)N = -NArCRCRNAr-, R = CH(3), and Ar = C(6)H(3)(i-Pr(2)) and the previous calculations on ethylene/propylene polymerization. Considerations have been given to the different possible acrylate complexes, as well as the transition states and the products (agostic complexes and the alternative chelates) for two acrylate insertion paths (1,2 and 2,1). The chelate-opening reactions have also been studied. The results revealed a strong electronic preference for the 2,1-insertion paths, with a barrier that is 4.5 kcal/mol lower than any other studied insertion pathway. In the real systems the 2,1-insertion of acrylate is preferred by 0.5 kcal/mol. The 2,1-insertion barrier calculated for the real system of 12.4 kcal/mol is in very good agreement with the experimental value of 12.1 kcal/mol. The six-member chelate is the most stable insertion product with an energy that is 21 kcal/mol lower than the kinetic insertion product. The reactions of the chelate opening by ethylene that start from the lowest energy complexes have the lowest barrier for the four-member ring (23 kcal/mol) and the highest for the six-member structure (30.4 kcal/mol). The high barrier for the opening of the six-member chelate suggests the possibility of a two-step chelate-opening mechanism. The internal barriers for the chelate-opening reactions starting from the higher energy complexes are lower then the one-step reaction that starts from the preferred complex and comparable to those of the ethylene insertion into the Pd-alkyl bond. While the chelate opening by a subsequent acrylate insertion seems to be facile for the generic catalyst, steric effects in the real catalyst are likely to decrease the acrylate pi-complexation energies and increase the insertion barriers to the extent where such a reaction becomes unfeasible.
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Affiliation(s)
- A Michalak
- Department of Chemistry, University of Calgary, University Dr. 2500, Calgary, Alberta, Canada T2N 1N4
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Abstract
It has been suggested that alterations of serotonin transport may be implicated in the pathogenesis of the neuropsychiatric symptoms encountered in acute liver failure. In order to address this issue, microdialysate concentrations of serotonin, its precursor L-tryptophan and metabolite 5-hydroxyindoleacetic acid (5-HIAA) as well as brain regional distribution of serotonin transporter ([3H]-citalopram) sites were measured in rats with acute liver failure resulting from hepatic devascularization. A significant loss of [3H]-citalopram sites was observed in dorsal Raphe nucleus, in frontal and frontoparietal cortices as well as in substantia nigra of rats with severe encephalopathy resulting from acute liver failure. In frontal cortex, this loss of transporter binding sites was accompanied by significant increases of L-tryptophan, serotonin and 5-HIAA concentrations in extracellular fluid. Pharmacological manipulation of the brain serotonin system could afford a novel therapeutic approach to the prevention of the neuropsychiatric symptoms characteristic of acute liver failure in humans.
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Affiliation(s)
- A Michalak
- Neuroscience Research Unit, CHUM Hôpital Saint-Luc, University of Montreal, 1058 St. Denis Street, Montreal, Que., Canada H2X 3J4
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Abstract
There is increasing evidence that central noradrenaline (NA) transport mechanisms are implicated in the central nervous system complications of acute liver failure. In order to assess this possibility, binding sites for the high affinity NA transporter ligand [3H]-nisoxetine were measured by quantitative receptor autoradiography in the brains of rats with acute liver failure resulting from hepatic devascularization and in appropriate controls. In vivo microdialysis was used to measure extracellular brain concentrations of NA. Severe encephalopathy resulted in a significant loss of [3H]-nisoxetine sites in frontal cortex and a concomitant increase in extracellular brain concentrations of NA in rats with acute liver failure. A loss of transporter sites was also observed in thalamus of rats with acute liver failure. This loss of NA transporter sites could result from depletion of central NA stores due to a reserpine-like effect of ammonia which is known to accumulate to millimolar concentrations in brain in ischemic liver failure. Impaired NA transport and the consequent increase in synaptic concentrations and increased stimulation of neuronal and astrocytic noradrenergic receptors could be implicated in the pathogenesis of the encephalopathy and brain edema characteristic of acute liver failure.
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Affiliation(s)
- A Michalak
- Neuroscience Research Unit, Centre Hospitalier de l'Université de Montréal (CHUM), Campus Saint-Luc, 1058 St. Denis Street, Quebec, H2X3J4, Montreal, Canada
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Rose C, Michalak A, Pannunzio M, Chatauret N, Rambaldi A, Butterworth RF. Mild hypothermia delays the onset of coma and prevents brain edema and extracellular brain glutamate accumulation in rats with acute liver failure. Hepatology 2000; 31:872-7. [PMID: 10733542 DOI: 10.1053/he.2000.5923] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Abstract
Mild hypothermia is effective in the prevention of brain edema associated with cerebral ischemia and traumatic brain injury. Brain edema is also a serious complication of acute liver failure (ALF). To assess the effectiveness of hypothermia in ALF, groups of rats were subjected to hepatic devascularization (portacaval anastomosis, followed 48 hours later by hepatic artery ligation), and body temperatures were maintained at either 35 degrees C (hypothermic) or 37 degrees C (normothermic). Mild hypothermia resulted in a significant delay in the onset of severe encephalopathy and in reduction of brain water content compared with normothermic ALF rats (control [n = 8] 80.22%; ALF-37 degrees C [n = 8] 81.74%; ALF-35 degrees C [n = 8] 80.48% [P <.01 compared with ALF-37 degrees C]). This protective effect was accompanied by a significant reduction of cerebrospinal fluid (CSF) (but not plasma) ammonia concentrations (CSF ammonia: control: 0.05 mg/dL; ALF-37 degrees C: 1.01 mg/dL; ALF-35 degrees C: 0.07 mg/dL, P <.01 compared with ALF-37 degrees C). In vivo cerebral microdialysis studies revealed that mild hypothermia resulted in a significant reduction of extracellular glutamate concentrations in the brains of rats with ALF (control: 1. 06 micromol/L; ALF-37 degrees C: 2.74 micromol/L; ALF-35 degrees C: 1.49 micromol/L [P <.01 compared with ALF-37 degrees C]). These findings suggest that: 1) mild hypothermia is an effective approach to the prevention of the central nervous system consequences of experimental ALF; and that 2) the beneficial effect of hypothermia is mediated via mechanisms involving reduced blood-brain transfer of ammonia and/or reduction of extracellular brain glutamate concentrations. Mild hypothermia may be an effective approach to delay the onset of brain edema in patients with ALF awaiting liver transplantation.
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Affiliation(s)
- C Rose
- Neuroscience Research Unit, Centre Hospitalier de l'Université de Montréal (Campus Saint-Luc), Montréal, Québec, Canada
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Desjardins P, Rao KV, Michalak A, Rose C, Butterworth RF. Effect of portacaval anastomosis on glutamine synthetase protein and gene expression in brain, liver and skeletal muscle. Metab Brain Dis 1999; 14:273-80. [PMID: 10850554 DOI: 10.1023/a:1020741226752] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The effects of chronic liver insufficiency resulting from end-to-side portacaval anastomosis (PCA) on glutamine synthetase (GS) activities, protein and gene expression were studied in brain, liver and skeletal muscle of male adult rats. Four weeks following PCA, activities of GS in cerebral cortex and cerebellum were reduced by 32% and 37% (p<0.05) respectively whereas GS activities in muscle were increased by 52% (p<0.05). GS activities in liver were decreased by up to 90% (p<0.01), a finding which undoubtedly reflects the loss of GS-rich perivenous hepatocytes following portal-systemic shunting. Immunoblotting techniques revealed no change in GS protein content of brain regions or muscle but a significant loss in liver of PCA rats. GS mRNA determined by semi-quantitative RT-PCR was also significantly decreased in the livers of PCA rats compared to sham-operated controls. These findings demonstrate that PCA results in a loss of GS gene expression in the liver and that brain does not show a compensatory induction of enzyme activity, rendering it particularly sensitive to increases in ammonia in chronic liver failure. The finding of a post-translational increase of GS in muscle following portacaval shunting suggests that, in chronic liver failure, muscle becomes the major organ responsible for the removal of excess blood-borne ammonia.
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Affiliation(s)
- P Desjardins
- Neuroscience Research Unit, Centre Hospitalier de l'Université de Montréal, Quebec, Canada
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Rose C, Michalak A, Rao KV, Quack G, Kircheis G, Butterworth RF. L-ornithine-L-aspartate lowers plasma and cerebrospinal fluid ammonia and prevents brain edema in rats with acute liver failure. Hepatology 1999; 30:636-40. [PMID: 10462368 DOI: 10.1002/hep.510300311] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Brain edema sufficient to cause intracranial hypertension and brain herniation remains a major cause of mortality in acute liver failure (ALF). Studies in experimental animal models of ALF suggest a role for ammonia in the pathogenesis of both encephalopathy and brain edema in this condition. As part of a series of studies to evaluate the therapeutic efficacy of ammonia-lowering agents, groups of rats with ALF caused by hepatic devascularization were treated with L-ornithine-L-aspartate (OA), an agent shown previously to be effective in reducing blood ammonia concentrations in both experimental and human chronic liver failure. Treatment of rats in ALF with infusions of OA (0.33 g/kg/h, intravenously) resulted in normalization of plasma ammonia concentrations and in a significant delay in onset of severe encephalopathy. More importantly, brain water content was significantly reduced in OA-treated rats with ALF. These protective effects of OA were accompanied by increased plasma concentrations of several amino acids including glutamate, gamma-aminobutyric acid (GABA), taurine, and alanine, as well as the branched-chain amino acids, leucine, isoleucine, and valine. Increased availability of glutamate following OA treatment provides the substrate for the major ammonia-removal mechanism (glutamine synthetase). Plasma (but not cerebrospinal fluid) glutamine concentrations were increased 2-fold (P <.02) in OA-treated rats, consistent with increased muscle glutamine synthesis. Direct measurement of glutamine synthetase activities revealed a 2-fold increase following OA treatment. These findings demonstrate a significant ammonia-lowering effect of OA together with a protective effect on the development of encephalopathy and brain edema in this model of ALF.
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Affiliation(s)
- C Rose
- Neuroscience Research Unit, Centre Hospitalier de l'Université de Montréal (Campus Saint-Luc), Montreal, Que., Canada H2X 3J4
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Rose C, Butterworth RF, Zayed J, Normandin L, Todd K, Michalak A, Spahr L, Huet PM, Pomier-Layrargues G. Manganese deposition in basal ganglia structures results from both portal-systemic shunting and liver dysfunction. Gastroenterology 1999; 117:640-4. [PMID: 10464140 DOI: 10.1016/s0016-5085(99)70457-9] [Citation(s) in RCA: 213] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS Manganese (Mn) deposition could be responsible for the T(1)-weighted magnetic resonance signal hyperintensities observed in cirrhotic patients. These experiments were designed to assess the regional specificity of the Mn increases as well as their relationship to portal-systemic shunting or hepatobiliary dysfunction. METHODS Mn concentrations were measured in (1) brain samples from basal ganglia structures (pallidum, putamen, caudate nucleus) and cerebral cortical structures (frontal, occipital cortex) obtained at autopsy from 12 cirrhotic patients who died in hepatic coma and from 12 matched controls; and from (2) brain samples (caudate/putamen, globus pallidus, frontal cortex) from groups (n = 8) of rats either with end-to-side portacaval anastomosis, with biliary cirrhosis, or with fulminant hepatic failure as well as from sham-operated and normal rats. RESULTS Mn content was significantly increased in frontal cortex (by 38%), occipital cortex (by 55%), pallidum (by 186%), putamen (by 66%), and caudate (by 54%) of cirrhotic patients compared with controls. Brain Mn content did not correlate with patient age, etiology of cirrhosis, or history of chronic hepatic encephalopathy. In cirrhotic and portacaval-shunted rats, Mn content was increased in pallidum (by 27% and 57%, respectively) and in caudate/putamen (by 57% and 67%, respectively) compared with control groups. Mn concentration in pallidum was significantly higher in portacaval-shunted rats than in cirrhotic rats. No significant changes in brain Mn concentrations were observed in rats with acute liver failure. CONCLUSIONS These findings suggest that brain Mn deposition results both from portal-systemic shunting and from liver dysfunction.
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Affiliation(s)
- C Rose
- Neuroscience Research Unit, Centre Hospitalier de l'Université de Montréal, Campus Saint-Luc, Université de Montréal, Québec, Canada
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Affiliation(s)
- A. Michalak
- Department of Computational Methods in Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Cracow, Poland, Eenheid Algemene Chemie, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium, and K. Gumiński Department of Theoretical Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Cracow, Poland
| | - F. De Proft
- Department of Computational Methods in Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Cracow, Poland, Eenheid Algemene Chemie, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium, and K. Gumiński Department of Theoretical Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Cracow, Poland
| | - P. Geerlings
- Department of Computational Methods in Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Cracow, Poland, Eenheid Algemene Chemie, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium, and K. Gumiński Department of Theoretical Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Cracow, Poland
| | - R. F. Nalewajski
- Department of Computational Methods in Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Cracow, Poland, Eenheid Algemene Chemie, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium, and K. Gumiński Department of Theoretical Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Cracow, Poland
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Chandra AK, Michalak A, Nguyen MT, Nalewajski RF. Regional Matching of Atomic Softnesses in Chemical Reactions: A Two-Reactant Charge Sensitivity Study. J Phys Chem A 1998. [DOI: 10.1021/jp983122a] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- A. K. Chandra
- Department of Chemistry, University of Leuven, Celestinijnenlaan 200F, B-3001 Leuven, Belgium, Department of Computational Methods in Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Cracow, Poland, and K. Gumiński Department of Theoretical Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Cracow, Poland
| | - A. Michalak
- Department of Chemistry, University of Leuven, Celestinijnenlaan 200F, B-3001 Leuven, Belgium, Department of Computational Methods in Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Cracow, Poland, and K. Gumiński Department of Theoretical Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Cracow, Poland
| | - M. T. Nguyen
- Department of Chemistry, University of Leuven, Celestinijnenlaan 200F, B-3001 Leuven, Belgium, Department of Computational Methods in Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Cracow, Poland, and K. Gumiński Department of Theoretical Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Cracow, Poland
| | - R. F. Nalewajski
- Department of Chemistry, University of Leuven, Celestinijnenlaan 200F, B-3001 Leuven, Belgium, Department of Computational Methods in Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Cracow, Poland, and K. Gumiński Department of Theoretical Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Cracow, Poland
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Rose C, Michalak A, Pannunzio P, Therrien G, Quack G, Kircheis G, Butterworth RF. L-ornithine-L-aspartate in experimental portal-systemic encephalopathy: therapeutic efficacy and mechanism of action. Metab Brain Dis 1998; 13:147-57. [PMID: 9699922 DOI: 10.1023/a:1020613314572] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Strategies aimed at the lowering of blood ammonia remain the treatment of choice in portal-systemic encephalopathy (PSE). L-ornithine-L-aspartate (OA) has recently been shown to be effective in the prevention of ammonia-precipitated coma in humans with PSE. These findings prompted the study of mechanisms of the protective effect of OA in portacaval-shunted rats in which reversible coma was precipitated by ammonium acetate administration (3.85 mmol/kg i.p.). OA infusions (300 mg/kg/h, i.v) offered complete protection in 12/12 animals compared to 0/12 saline-infused controls. This protective effect was accompanied by significant reductions of blood ammonia, concomitant increases of urea production and significant increases in blood and cerebrospinal fluid (CSF) glutamate and glutamine. Increased CSF concentrations of leucine and alanine also accompanied the protective effect of OA. These findings demonstrate the therapeutic efficacy of OA in the prevention of ammonia-precipitated coma in portacaval-shunted rats and suggest that this protective effect is both peripherally-mediated (increased urea and glutamine synthesis) and centrally-mediated (increased glutamine synthesis).
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Affiliation(s)
- C Rose
- Neuroscience Research Unit, Centre Hospitalier de l'Université de Montréal (Campus Saint-Luc), Quebec, Canada
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20
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Abstract
These is increasing evidence to suggest that central noradrenergic mechanisms may contribute to the central nervous system manifestations of acute liver failure. To further elucidate this possibility, extracellular brain concentrations of the monoamines, noradrenaline (NA), dopamine (DA), and serotonin, were measured by high-performance liquid chromatography with electrochemical detection in microdialysates from the extracellular compartment of frontal cortex in rats with acute (ischemic) liver failure at various times during the progression of encephalopathy and brain edema, as well as in obligate control groups of animals. In addition, binding sites for the noradrenergic receptor subtype ligands, [3H]-prazosin (alpha1 sites), [3H]-RX821002 (alpha2 sites), and [125]I-iodopindolol (beta sites), were assessed using quantitative receptor autoradiography in regions of the brains of rats at coma stage of acute liver failure and of control groups of animals. Coma stages of encephalopathy in acute liver failure were associated with selectively increased noradrenaline concentrations (P < .05) and a concomitant selective loss of alpha1 and beta1 sites in frontal cortex and thalamus. These findings add to a growing body of evidence that central noradrenergic function is modified in acute liver failure and suggest that alpha1/beta1 receptor-mediated noradrenergic mechanisms may play a role in the pathogenesis of brain edema and encephalopathy in this condition.
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Affiliation(s)
- A Michalak
- Neuroscience Research Unit, Hôpital Saint-Luc, University of Montreal, Quebec, Canada
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Nalewajski RF, Michalak A. Charge Sensitivity/Bond-Order Analysis of Reactivity Trends in Allyl−[MoO3] Chemisorption Systems: A Comparison between (010) and (100) Surfaces. J Phys Chem A 1998. [DOI: 10.1021/jp972566o] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- R. F. Nalewajski
- K. Gumiński Department of Theoretical Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Cracow, Poland
| | - A. Michalak
- Department of Computational Methods in Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Cracow, Poland
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Michalak A, Butterworth RF. Selective increases of extracellular brain concentrations of aromatic and branched-chain amino acids in relation to deterioration of neurological status in acute (ischemic) liver failure. Metab Brain Dis 1997; 12:259-69. [PMID: 9475499 DOI: 10.1007/bf02674670] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Previous reports based on studies in brain tissue from humans and experimental animals suggest that aromatic amino acids (AAAs) and branched-chain amino acids (BCAA's) accumulate in brain in acute liver failure. In order to assess these changes in relation to the severity of neurological impairment and to the degree of hyperammonemia, AAAs and BCAAs were measured in vivo by cerebral microdialysis in frontal cortex of rats at various stages during the development of hepatic encephalopathy due to acute liver failure resulting from portacaval anastomosis followed by hepatic artery ligation. Extracellular brain concentrations of AAAs and of valine and leucine were elevated 2 to 4-fold following hepatic devascularization and these increases were significantly correlated to arterial ammonia concentration (r= 0.71-0.84, p<0.05). Extracellular concentrations of tyrosine paralleled the deterioration of neurological status in acute liver failure rats. In view of their role as precursors of monoamine neurotransmitters, ammonia-induced alterations of intracellular/extracellular brain concentration ratios for AAAs could account for altered neuronal excitability and contribute to the encephalopathy characteristic of acute liver failure.
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Affiliation(s)
- A Michalak
- Neuroscience Research Unit, Pavillon Saint-Luc (University of Montreal), Quebec, Canada
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Michalak A, Butterworth RF. Ornithine transcarbamylase deficiency: pathogenesis of the cerebral disorder and new prospects for therapy. Metab Brain Dis 1997; 12:171-82. [PMID: 9346466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Ornithine Transcarbamylase (OTC) is a key urea cycle enzyme. Congenital OTC deficiencies in humans result in hyperammonemia and a spectrum of neurological symptoms including hypotonia, seizures and mental retardation. Neuropathologic evaluation reveals cerebral atrophy, ventricular enlargement and Alzheimer type II astrocytosis. Using an animal model of congenital OTC deficiency, the sparse fur (spf) mouse, recent studies have revealed significant alterations of cholinergic, serotoninergic and glutamatergic neurotransmitter systems. Possible pathophysiologic mechanisms responsible for neuronal cell loss in OTC deficiency include a deficit in cerebral energy metabolism, and glutamate excitotoxicity. Therapy continues to rely on alternative substrate administration including sodium benzoate and sodium phenylacetate. Experimental evidence suggests that acetyl-L-carnitine and glutamate (NMDA) receptor antagonists could be potentially useful therapeutic agents. Liver transplantation is effective in many patients and recent experimental studies using adenoviral vectors suggest that gene therapy may ultimately be useful in the treatment of congenital OTC deficiency.
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Affiliation(s)
- A Michalak
- Neuroscience Research Unit, Hôpital Saint-Luc (University of Montreal), Quebec, Canada
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Knecht K, Michalak A, Rose C, Rothstein JD, Butterworth RF. Decreased glutamate transporter (GLT-1) expression in frontal cortex of rats with acute liver failure. Neurosci Lett 1997; 229:201-3. [PMID: 9237493 DOI: 10.1016/s0304-3940(97)00444-8] [Citation(s) in RCA: 143] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
It has been suggested that reduced astrocytic uptake of neuronally released glutamate contributes to the pathogenesis of hepatic encephalopathy in acute liver failure. In order to further address this issue, the recently cloned and sequenced astrocytic glutamate transporter GLT-1 was studied in brain preparations from rats with ischemic liver failure induced by portacaval anastomosis followed 24 h later by hepatic artery ligation and from appropriate sham-operated controls. GLT-1 expression was studied using reverse transcriptase-polymerase chain reaction (RT-PCR). Expression of GLT-1 transcript was significantly decreased in frontal cortex at coma stages of acute liver failure. Western blotting using a polyclonal antibody to GLT-1 revealed a concomitant decrease in expression of transporter protein in the brains of rats with acute liver failure. Reduced capacity of astrocytes to reuptake neuronally released glutamate, resulting from a GLT-1 transporter deficit and the consequently compromised neuron-astrocytic trafficking of glutamate could contribute to the pathogenesis of hepatic encephalopathy and brain edema, two major complications of acute liver failure.
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Affiliation(s)
- K Knecht
- Neuroscience Research Unit, Hôpital Saint-Luc (University of Montreal), Quebec, Canada
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Michalak A, Butterworth RF. Selective loss of binding sites for the glutamate receptor ligands [3H]kainate and (S)-[3H]5-fluorowillardiine in the brains of rats with acute liver failure. Hepatology 1997; 25:631-5. [PMID: 9049210 DOI: 10.1002/hep.510250323] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
There is increasing evidence that alterations of glutamatergic function are implicated in the pathogenesis of central nervous system consequences of acute liver failure. The aim of the study was to assess the integrity of glutamate receptors in the brain in experimental ischemic liver failure using quantitative receptor autoradiography and the selective ligands [3H]MK801 (for N-methyl-D-aspartate [NMDA] sites), [3H]5-fluorowillardiine (for non-NMDA, alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid [AMPA] subclass sites), and [3H]kainate (for non-NMDA, kainate subclass sites). At coma stages of encephalopathy, a selective loss of up to 60% of binding sites for the kainate- and AMPA-receptor ligands was observed in cerebral cortical and hippocampal structures as well as in the hypothalamus and cerebellum. The finding of a selective loss of AMPA sites at coma stages of encephalopathy in this model of acute liver failure is consistent with previous electrophysiological reports of inhibition of AMPA-mediated neuronal depolarization resulting from exposure of hippocampal neurons to millimolar concentrations of ammonia. On the other hand, the present study showed that binding sites for the NMDA-receptor ligand [3H]MK801 at coma stages of encephalopathy in acute liver failure were within normal limits in all brain structures examined. NMDA sites are uniquely neuronal, whereas kainate and AMPA sites are localized on both neurons and astrocytes. Therefore, the selective loss of non-NMDA sites in acute liver failure may also reflect astrocytic changes in this condition. Because astrocytic glutamate receptors are implicated in K+ and neurotransmitter reuptake, alterations in their density could result in altered neuronal excitability and thus be responsible for the neurological dysfunction characteristic of hepatic encephalopathy in acute liver failure.
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Affiliation(s)
- A Michalak
- Neuroscience Research Unit, University of Montreal, Quebec, Canada
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26
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Affiliation(s)
- A Michalak
- Neuroscience Research Unit, Hôpital Saint-Luc (University of Montreal), Quebec, Canada
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Nalewajski RF, Michalak A. Charge Sensitivity and Bond-Order Analysis of Reactivity Trends in Allyl−[MoO3] Chemisorption Systems: Two-Reactant Approach. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp962291x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- R. F. Nalewajski
- K. Gumiński Department of Theoretical Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Cracow, Poland
| | - A. Michalak
- Department of Computational Methods in Chemistry, Jagiellonian University, R. Ingardena 3, 30-060 Cracow, Poland
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Michalak A, Rose C, Butterworth J, Butterworth RF. Neuroactive amino acids and glutamate (NMDA) receptors in frontal cortex of rats with experimental acute liver failure. Hepatology 1996; 24:908-13. [PMID: 8855196 DOI: 10.1002/hep.510240425] [Citation(s) in RCA: 133] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
It has been proposed that alterations of excitatory and inhibitory amino acids play a role in the pathogenesis of hepatic encephalopathy in acute liver failure. To evaluate this possibility, in vivo cerebral microdialysis was used to sample extracellular concentrations of amino acids in the frontal cortex of unanesthetized rats at various times during the progression of encephalopathy resulting from acute liver failure. Liver failure was induced by portacaval anastomosis followed 24 hours later by hepatic artery ligation. Dialysate concentrations of amino acids were measured by high-performance liquid chromatography (HPLC) with fluorescence detection. Deterioration of neurological status was accompanied by two- to four-fold increases in extracellular glutamate, glutamine, and glycine; concentrations of gamma-aminobutyric acid (GABA) and taurine were unchanged. Densities of binding sites for the glutamate (N-methyl-D-aspartate [NMDA]) receptor ligand 3H-MK801, assessed using quantitative receptor autoradiography, however, were unchanged in the frontal cortex of rats at coma stages of ischemic liver failure. Increased extracellular glutamate concentrations were positively correlated with the severity of encephalopathy and with arterial ammonia concentrations. Such changes may result from an ammonia-induced reduction in the capacity for astrocytes to uptake glutamate. Increased extracellular glutamate in brain, together with increases in concentrations of glycine, a positive allosteric modulator of glutamate (NMDA) receptors, are consistent with increased NMDA-related glutamatergic neurotransmission in this model of acute liver failure. Increased extracellular glutamate, therefore, could contribute to the pathogenesis of hepatic encephalopathy and brain edema in acute liver failure.
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Affiliation(s)
- A Michalak
- Neuroscience Research Unit, Hôpital Saint-Luc (University of Montreal), Quebec, Canada
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29
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Affiliation(s)
- K. Hermann
- Fritz-Haber-Institut der MPG, Faradayweg 4–6, D-14195 Berlin, Germany
| | - M. Witko
- Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, ul. Niezapominajek, 30239 Cracow, Poland
| | - A. Michalak
- Department of Computational Methods in Chemistry, Faculty of Chemistry, Jagiellonian University, R. Ingardena 3, 30060 Cracow, Poland
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Michalak A, Qureshi IA. Free and esterified coenzyme A in the liver and muscles of chronically hyperammonemic mice treated with sodium benzoate. Biochem Mol Med 1995; 54:96-104. [PMID: 8581365 DOI: 10.1006/bmme.1995.1014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Ammonia toxicity and relative sodium benzoate toxicity alters the energy metabolism, leading to a decrease of adenosine triphosphate and free coenzyme A levels. The object of the present study was to analyze the hepatic and muscular acyl-coenzyme A profiles in chronically hyperammonemic mice treated with varying doses of the sodium benzoate. An enzymatic method was used for the measurement of free coenzyme A, acetyl-coenzyme A, and medium and long chain acyl-coenzyme A. Untreated chronic hyperammonemia resulted in a decrease in acetyl-coenzyme A and an increase in the long chain acyl-coenzyme A in the liver, accompanied by an increase in total coenzyme A in the muscular tissues. Treatment with sodium benzoate at moderate doses, caused a decrease in the hepatic free and esterified coenzyme A while these were increased at higher doses. We conclude that chronic hyperammonemia is responsible for qualitative changes in the free and esterified coenzyme A profile in the liver, while causing qualitative and quantitative changes in the muscular tissue, probably due to an inhibition of mitochondrial oxidation. The sodium benzoate had a biphasic effect on the hepatic content of free and esterified coenzyme A, suggesting a degradation of coenzyme A at moderate doses. However, at a higher dose of benzoate, the possibility of glycine mobilization and/or a significant formation of acylcarnitines is proposed as an important factor in an increase of the hepatic total coenzyme A.
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Affiliation(s)
- A Michalak
- Research Center, Ste-Justine Hospital 3175, Montréal, Québec Canada
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Michalak A, Qureshi IA. Tissue acylcarnitine and acyl-coenzyme A profiles in chronically hyperammonemic mice treated with sodium benzoate and supplementary L-carnitine. Biomed Pharmacother 1995; 49:350-7. [PMID: 8562862 DOI: 10.1016/0753-3322(96)82664-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The aim of the present study, was to establish the hepatic profile of acyl-coenzyme A (acyl-CoA) in relation to the hepatic profile of acylcarnitines in chronically hyperammonemic spf mice (hereditary deficiency in ornithine transcarbamylase) treated with sodium benzoate alone or in combination with L-carnitine. The muscular profile of the acylcarnitines and the stability of sarcolemma were also assessed in the same mice. Following administration of sodium benzoate, we observed decreases in hepatic total and free coenzyme A and in acetyl-CoA, which was accompanied by an increase in hepatic acyl-CoA. This treatment also resulted in increased free carnitine, decreased total carnitine, and decreased short and medium chain acylcarnitines in the liver. Increases in plasma creatine kinase levels, muscular free, total, and in short and medium chain acylcarnitines were also observed in this treatment group. In mice receiving a combination of sodium benzoate and L-carnitine, increases in free and total coenzyme A, acetyl-CoA and in free, total and esterified hepatic carnitines were observed. In this treatment group, the plasma level of creatine kinase was found to be reduced, while the free muscular carnitine was increased. Our results indicate that sodium benzoate is implicated in the decrease of total hepatic coenzyme A, through either an inhibition of CoA synthesis or activation of its degradation. The distribution of hepatic coenzyme-A and of hepatic and muscular carnitine (free or esterified) is altered following administration of sodium benzoate which results in a further destabilization of the sarcolemma induced by hyperammonemia. Supplemental treatment with L-carnitine was shown to have a positive effect by increasing hepatic coenzyme A and carnitine levels and restoring the stability of the sarcolemma caused by the treatment of sodium benzoate alone.
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Affiliation(s)
- A Michalak
- Service de Génétique Médicale, Hôpital Ste-Justine, Montréal, Québec, Canada
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Qureshi IA, Ratnakumari L, Michalak A, Giguère R, Cyr D, Butterworth RF. A profile of cerebral and hepatic carnitine, ammonia, and energy metabolism in a model of organic aciduria: BALB/cByJ mouse with short-chain acyl-CoA dehydrogenase deficiency. Biochem Med Metab Biol 1993; 50:145-58. [PMID: 8260192 DOI: 10.1006/bmmb.1993.1056] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Spontaneous animal models of inborn errors of metabolism are valuable tools for defining the pathogenesis of these disorders and also the mechanism of various therapeutic approaches. In the present study, we have employed BALB/cByJ mice with an autosomal recessive deficiency of short-chain acyl-CoA dehydrogenase (SCAD). These animals were characterized by a marked urinary excretion of ethylmalonic and methylsuccinic acids along with butyrylglycine. Using adult homozygous mice we have studied the basic cerebral and hepatic profile of carnitine, ammonia, and energy metabolism. The effects of fasting and a short-term supplement of L-carnitine have been evaluated in comparison with control BALB/cJ mice. The mutant mice had low levels of acetyl-CoA and high levels of lactate compared to control mice. Fasting aggravated this condition by further decreasing acetyl-CoA and increasing lactate levels in the mutant mice. Free carnitine levels were significantly decreased in liver with fasting. Long-chain acylcarnitines were significantly lower in the brain of mutant mice. A short-term supplementation of L-carnitine resulted in general increases of carnitine levels in liver and muscle, but they still remained lower in mutant BALB/cByJ mice as compared to control BALB/cJ mice. L-Carnitine treatment increased cerebral CoA-SH levels and both hepatic and cerebral acetyl-CoA levels in mutant mice. Hyperammonemia which has been described frequently in acyl-CoA dehydrogenase deficiencies was not observed in adult BALB/cByJ mice. This could be due to a rapid conjugation of butyryl-CoA with glycine by an increased activity of glycine N-acyltransferase.
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Affiliation(s)
- I A Qureshi
- Centre de recherche, Hôpital Ste-Justine, Montreal, Quebec, Canada
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Michalak A, Qureshi IA. Carnitine musculaire chez les souris hyperammoniémiques: effet du traitement au benzoate de sodium. Can J Physiol Pharmacol 1993. [DOI: 10.1139/y93-065] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The object of this study was to measure carnitine levels in skeletal muscles of experimental mice with acute, subacute, and chronic hyperammonemia, with or without sodium benzoate treatment. Normal Swiss–ICR mice in which acute hyperammonemia was created through intraperitoneal injection of ammonium acetate showed a significant decrease in free carnitine in the skeletal muscles. The same phenomenon was observed in spf mice with chronic congenital hyperammonemia caused by an X-linked deficiency of liver ornithine transcarbamylase. In spf mice with subacute hyperammonemia created through treatment with an arginine-deficient diet, free carnitine of muscles increased compared with basal levels seen in chronic hyperammonemia. The changes in carnitine metabolism during chronic and subacute hyperammonemia were accompanied by a significant increase of creatine kinase levels in the plasma, which are an index of damage to the sarcolemma. A decrease in free and esterified levels of carnitine in the muscles was observed among normal mice treated with sodium benzoate. A decrease in esterified carnitine was also noticed among spf mice given an acute treatment with sodium benzoate as well as among normal and spf mice given a prolonged treatment with sodium benzoate. Plasma creatine kinase levels were high in normal mice, after both acute and prolonged treatments. However, the levels in spf mice treated with sodium benzoate were not significantly different from those in untreated spf controls in which a significant increase in plasma creatine kinase was already caused by chronic hyperammonemia. This study indicates that the metabolism and (or) distribution of carnitine go through significant changes during various levels of hyperammonemia, and that a treatment with sodium benzoate causes a secondary deficiency in carnitine of muscles. The increase in plasma levels of creatine kinase could signify a secondary effect of these factors on the function or the integrity of the sarcolemma.Key words: hyperammonemia, carnitine, sodium benzoate, mice, muscle.
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Michalak A, Qureshi IA. [Carnitine levels in muscle in mice with hyperammonemia: effect of treatment with sodium benzoate]. Can J Physiol Pharmacol 1993; 71:439-46. [PMID: 8242478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The object of this study was to measure carnitine levels in skeletal muscles of experimental mice with acute, subacute, and chronic hyperammonemia, with or without sodium benzoate treatment. Normal Swiss-ICR mice in which acute hyperammonemia was created through intraperitoneal injection of ammonium acetate showed a significant decrease in free carnitine in the skeletal muscles. The same phenomenon was observed in spf mice with chronic congenital hyperammonemia caused by an X-linked deficiency of liver ornithine transcarbamylase. In spf mice with subacute hyperammonemia created through treatment with an arginine-deficient diet, free carnitine of muscles increased compared with basal levels seen in chronic hyperammonemia. The changes in carnitine metabolism during chronic and subacute hyperammonemia were accompanied by a significant increase of creatine kinase levels in the plasma, which are an index of damage to the sarcolemma. A decrease in free and esterified levels of carnitine in the muscles was observed among normal mice treated with sodium benzoate. A decrease in esterified carnitine was also noticed among spf mice given an acute treatment with sodium benzoate as well as among normal and spf mice given a prolonged treatment with sodium benzoate. Plasma creatine kinase levels were high in normal mice, after both acute and prolonged treatments. However, the levels in spf mice treated with sodium benzoate were not significantly different from those in untreated spf controls in which a significant increase in plasma creatine kinase was already caused by chronic hyperammonemia.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- A Michalak
- Centre de recherche, Hôpital Sainte-Justine, Montréal, QC, Canada
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Michalak A, Lambert MA, Dallaire L, Melançon SB, Laframboise R, Lemieux B, Qureshi IA. [Hypocarnitinemia in patients affected by a primary defect of ammonia metabolism treated with sodium benzoate]. Diabete Metab 1990; 16:226-33. [PMID: 2210018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We have studied the plasma and urinary levels of free and esterified carnitine in 18 patients affected by a primary defect of ammonia metabolism, which had been managed with or without a therapy of sodium benzoate. None of these patients presented with any acute neurologic or digestive symptoms during the study. Our group of non-treated patients showed an increase in the levels of plasma esterified carnitine and an elevation of urinary concentration of free carnitine, while the levels of urinary esterified carnitine clearly approached the superior limits of normal values. The group treated with sodium benzoate showed a more profoundly disturbed plasma and urinary carnitine profile: a significantly lower plasma and urinary free carnitine, accompanied by a clearly increased esterified/free carnitine ratio. We did not find any evidence of a relationship between the plasma levels of free or esterified carnitine and the protein intake or the plasma ammonia concentration. We are proposing a hypothesis to explain the hypocarnitinemia seen in our patients being treated with benzoate, along with other modifications observed in the carnitine profile. We believe that a supplement of carnitine could be beneficial in the management of some of these patients.
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Affiliation(s)
- A Michalak
- Service de génétique médicale, Hôpital Sainte-Justine, Montréal, Canada
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Michalak A, Qureshi IA. Plasma and urinary levels of carnitine in different experimental models of hyperammonemia and the effect of sodium benzoate treatment. Biochem Med Metab Biol 1990; 43:163-74. [PMID: 2346672 DOI: 10.1016/0885-4505(90)90022-s] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The effect of hyperammonemia on plasma and urinary levels of carnitine was studied in different groups of +/Y (normal) and spf/Y (chronically hyperammonemic) mice. Experimental models of acute and subacute hyperammonemia were prepared in +/Y and spf/Y mice by the use of ammonium acetate ip injections and arginine-free diets, respectively. In acute hyperammonemia, the plasma levels of both free and acylcarnitines increased significantly whereas acyl/free carnitine ratio was decreased, indicating a mobilization of carnitine from the storage sites. The subacute hyperammonemia model showed the same tendency in respect of plasma and urinary carnitines; however, the values in plasma were more significantly different. The effect of sodium benzoate on plasma carnitine levels, during both an acute and a prolonged treatment, consisted in a significant lowering of free carnitine and a significant increase in the acyl/free carnitine ratio, in both +/Y normal and spf/Y mouse models. The changes in the urinary profile, on benzoate treatments, were not significant. These results demonstrate the individual effects of hyperammonemia and benzoate therapy on carnitine metabolism, which may be helpful in understanding and ameliorating the therapeutic approach to hereditary hyperammonemias.
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Affiliation(s)
- A Michalak
- Department of Pediatrics, University of Montreal, Québec, Canada
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Wichliński LM, Balcar-Boroń A, Pankowski M, Wysocki M, Szeligowski M, Swincow G, Krzyśko K, Michalak A, Szaflarska M. [Monitoring gentamicin and amikacin levels in the treatment of respiratory and urinary tract infections in children]. Pol Tyg Lek 1987; 42:959-63. [PMID: 3684775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Balcar-Boroń A, Pytel-Dabrowska T, Barankiewicz B, Michalak A, Trybuś L. [Primary liver cancer in the course of treatment of acquired aplastic anemia with oxymetholone in a 12-year-old girl]. Pediatr Pol 1981; 56:959-61. [PMID: 6272188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Balcar-Boroń A, Pytel-Dabrowska T, Michalak A, Barankiewicz B. [HBs antigenemia in children with various hematologic syndromes and its effect on the course of these diseases]. Pol Tyg Lek 1980; 35:1597-8. [PMID: 7208375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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40
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Michalak A, Michalak J, Jedrzejewski T. [Changes in the epithelium of the alveolar process in patients with metal or metallo-acrylic bridges]. Protet Stomatol 1980; 30:237-42. [PMID: 7019971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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41
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Margolis A, Planeta-Malecka I, Konopińska H, Michalak A. [Study of the calcium-phosphorus metabolism in a case of congenital hypothyroidism associated with urolithiasis]. Pediatr Pol 1970; 45:783-90. [PMID: 5449786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Margolis A, Planeta-Malecka I, Konopińska H, Michalak A. [Disturbances of calcium-phosphorus metabolism in hyperthyroidism and hypothyroidism]. Pediatr Pol 1970; 45:857-63. [PMID: 5449794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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43
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Nowak S, Bodalski J, Margolis A, Michalak A. [Attempts of the use of cytostatic agents in some forms of glomerulonephritis in children]. Pediatr Pol 1969; 44:549-60. [PMID: 5791319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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44
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Margolis A, Planeta-Malecka I, Michalak A. [Polyneuropathy in diabetic children]. Pediatr Pol 1969; 44:287-92. [PMID: 5784454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Bodalski J, Margolis A, Michalak A, Cieplowska K. [Difficulties in the diagnosis of pyelonephritis in children]. Pediatr Pol 1967; 42:765-773. [PMID: 6052285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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Margolis A, Michalak A, Nowicki S. [The hazard of hypoglycemia in diabetes in children]. Pediatr Pol 1966; 41:940-7. [PMID: 6005650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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