1
|
Swansson WD, Anderson BM, Yeoh SW, Lewis DJ. Management of minimal and overt hepatic encephalopathy with branched-chain amino acids: a review of the evidence. Eur J Gastroenterol Hepatol 2023; 35:812-821. [PMID: 37395232 DOI: 10.1097/meg.0000000000002595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Hepatic encephalopathy (HE) is a challenging complication of liver disease that is associated with substantial morbidity and mortality. Branched-chain amino acid (BCAA) supplementation in the management of HE is a debated topic. This narrative review aims to provide an up-to-date review of the topic and includes studies featuring patients with hepatocellular carcinoma. A review of the literature was performed using the online databases MEDLINE and EMBASE for studies between 2002 and December 2022. Keywords 'branched-chain amino acids', 'liver cirrhosis' and 'hepatic encephalopathy' were used. Studies were assessed for inclusion and exclusion criteria. Of 1045 citations, 8 studies met the inclusion criteria. The main outcomes reported for HE was changed in minimal HE (MHE) (n = 4) and/or incidence of overt HE (OHE) (n = 7). Two of the 4 studies reporting on MHE had improvement in psychometric testing in the BCAA group, but there was no change in the incidence of OHE in any of the 7 papers in the BCAA group. There were few adverse effects of BCAA supplementation. This review found weak evidence for BCAA supplementation for MHE, and no evidence for BCAAs for OHE. However, given the relative paucity and methodological heterogeneity of the current research, there is scope for future studies to examine the effects of varying timing, dosage, and frequency of BCAAs on outcomes such as HE. Importantly, research is also needed to examine BCAAs in conjunction with standard therapies for HE such as rifaximin and/or lactulose.
Collapse
Affiliation(s)
| | | | - Sern Wei Yeoh
- Melbourne Medical School, The University of Melbourne
- Department of Gastroenterology, Northern Health, Melbourne, VIC, Australia
| | - Diana J Lewis
- Melbourne Medical School, The University of Melbourne
- Department of Gastroenterology, Northern Health, Melbourne, VIC, Australia
| |
Collapse
|
2
|
Lim CG, Hahm MH, Lee HJ. Hepatic encephalopathy on magnetic resonance imaging and its uncertain differential diagnoses: a narrative review. JOURNAL OF YEUNGNAM MEDICAL SCIENCE 2023; 40:136-145. [PMID: 36624654 PMCID: PMC10076915 DOI: 10.12701/jyms.2022.00689] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 11/11/2022] [Indexed: 04/12/2023]
Abstract
Hepatic encephalopathy (HE) is a severe neuropsychiatric abnormality in patients with either acute or chronic liver failure. Typical brain magnetic resonance imaging findings of HE are bilateral basal ganglia high signal intensities due to manganese deposition in chronic liver disease and hyperintensity in T2, fluid-attenuated inversion recovery, or diffusion-weighted imaging (DWI) with hemispheric white matter changes including the corticospinal tract. Low values on apparent diffusion coefficient mapping of the affected area on DWI, indicating cytotoxic edema, can be observed in acute HE. However, neuropsychological impairment in HE ranges from mild deficits in psychomotor abilities affecting quality of life to stupor or coma with higher grades of hepatic dysfunction. In particular, the long-lasting compensatory mechanisms for the altered metabolism in chronic liver disease make HE imaging results variable. Therefore, the clinical relevance of imaging findings is uncertain and differentiating HE from other metabolic diseases can be difficult. The recent introduction of concepts such as "acute-on-chronic liver failure (ACLF)," a new clinical entity, has led to a change in the clinical view of HE. Accordingly, there is a need to establish a corresponding concept in the field of neuroimaging diagnosis. Herein, we review HE from a historical and etiological perspective to increase understanding of brain imaging and help establish an imaging approach for advanced new concepts such as ACLF. The purpose of this manuscript is to provide an understanding of HE by reviewing neuroimaging findings based on pathological and clinical concepts of HE, thereby assisting in neuroimaging interpretation.
Collapse
Affiliation(s)
- Chun Geun Lim
- Department of Radiology, Kyungpook National University Hospital, School of Medicine, Kyungpook National University, Daegu, Korea
| | - Myong Hun Hahm
- Department of Radiology, Kyungpook National University Hospital, School of Medicine, Kyungpook National University, Daegu, Korea
| | - Hui Joong Lee
- Department of Radiology, Kyungpook National University Hospital, School of Medicine, Kyungpook National University, Daegu, Korea
- Corresponding author: Hui Joong Lee, MD, PhD Department of Radiology, Kyungpook National University Hospital, School of Medicine, Kyungpook National University, 130 Dongduk-ro, Jung-gu, Daegu 41944, Korea Tel.: +82-53-420-5397 • Fax: +82-53-422-2677 • E-mail:
| |
Collapse
|
3
|
Giménez-Garzó C, Urios A, Agustí A, Mangas-Losada A, García-García R, Escudero-García D, Kosenko E, Ordoño JF, Tosca J, Giner-Durán R, Serra MA, Felipo V, Montoliu C. Cirrhotic patients with minimal hepatic encephalopathy have increased capacity to eliminate superoxide and peroxynitrite in lymphocytes, associated with cognitive impairment. Free Radic Res 2017; 52:118-133. [PMID: 29262736 DOI: 10.1080/10715762.2017.1420183] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Patients with minimal hepatic encephalopathy (MHE) show increased oxidative stress in blood. We aimed to assess whether MHE patients show alterations in different types of blood cells in (a) basal reactive oxygen and nitrogen species levels; (b) capacity to metabolise these species. To assess the mechanisms involved in the altered capacity to metabolise these species we also analysed: (c) peroxynitrite formation and d) peroxynitrite reaction with biological molecules. Levels of reactive oxygen and nitrogen species were measured by flow cytometry in blood cell populations from cirrhotic patients with and without MHE and controls, under basal conditions and after adding generators of superoxide (plumbagin) or nitric oxide (NOR-1) to assess the capacity to eliminate them. Under basal conditions, MHE patients show reduced superoxide and peroxynitrite levels and increased nitric oxide (NO) and nitrotyrosine levels. In patients without MHE plumbagin strongly increases cellular superoxide, moderately peroxynitrite and reduces NO levels. In MHE patients, plumbagin increases slightly superoxide and strongly peroxynitrite levels and affects slightly NO levels. NOR-1 increases NO levels much less in patients with than without MHE. These data show that the mechanisms and the capacity to eliminate cellular superoxide, NO and peroxynitrite are enhanced in MHE patients. Superoxide elimination is enhanced through reaction with NO to form peroxynitrite which, in turn, is eliminated by enhanced reaction with biological molecules, which could contribute to cognitive impairment in MHE. The data show that basal free radical levels do not reflect the oxidative stress status in MHE.
Collapse
Affiliation(s)
- Carla Giménez-Garzó
- a Laboratory of Neurobiology , Centro Investigación Príncipe Felipe de Valencia , Valencia , Spain
| | - Amparo Urios
- a Laboratory of Neurobiology , Centro Investigación Príncipe Felipe de Valencia , Valencia , Spain.,b Fundación Investigación Hospital Clínico de Valencia, Instituto de Investigación Sanitaria-INCLIVA , Valencia , Spain
| | - Ana Agustí
- b Fundación Investigación Hospital Clínico de Valencia, Instituto de Investigación Sanitaria-INCLIVA , Valencia , Spain
| | - Alba Mangas-Losada
- b Fundación Investigación Hospital Clínico de Valencia, Instituto de Investigación Sanitaria-INCLIVA , Valencia , Spain
| | - Raquel García-García
- a Laboratory of Neurobiology , Centro Investigación Príncipe Felipe de Valencia , Valencia , Spain
| | - Desamparados Escudero-García
- c Unidad de Digestivo, Hospital Clínico de Valencia , Departamento de Medicina, Universidad de Valencia , Valencia , Spain
| | - Elena Kosenko
- d Laboratory of Modeling and Bioinformatics , Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences , Pushchino , Russia
| | - Juan Fermín Ordoño
- e Servicio Neurofisiología , Hospital Arnau de Vilanova , Valencia , Spain.,f Psychopatology and Neurophysiology Unit , Paterna Mental Health Center, CIBERSAM , Valencia , Spain
| | - Joan Tosca
- c Unidad de Digestivo, Hospital Clínico de Valencia , Departamento de Medicina, Universidad de Valencia , Valencia , Spain
| | | | - Miguel Angel Serra
- c Unidad de Digestivo, Hospital Clínico de Valencia , Departamento de Medicina, Universidad de Valencia , Valencia , Spain
| | - Vicente Felipo
- a Laboratory of Neurobiology , Centro Investigación Príncipe Felipe de Valencia , Valencia , Spain
| | - Carmina Montoliu
- b Fundación Investigación Hospital Clínico de Valencia, Instituto de Investigación Sanitaria-INCLIVA , Valencia , Spain.,h Departamento de Patología, Facultad de Medicina , Universidad de Valencia , Valencia , Spain
| |
Collapse
|
4
|
Kosenko EA, Tikhonova LA, Alilova GA, Montoliu C, Barreto GE, Aliev G, Kaminsky YG. Portacaval shunting causes differential mitochondrial superoxide production in brain regions. Free Radic Biol Med 2017; 113:109-118. [PMID: 28964916 DOI: 10.1016/j.freeradbiomed.2017.09.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 09/08/2017] [Accepted: 09/25/2017] [Indexed: 01/23/2023]
Abstract
The portacaval shunting (PCS) prevents portal hypertension and recurrent bleeding of esophageal varices. On the other hand, it can induce chronic hyperammonemia and is considered to be the best model of mild hepatic encephalopathy (HE). Pathogenic mechanisms of HE and dysfunction of the brain in hyperammonemia are not fully elucidated, but it was originally suggested that the pathogenetic defect causes destruction of antioxidant defense which leads to an increase in the production of reactive oxygen species (ROS) and the occurrence of oxidative stress. In order to gain insight into the pathogenic mechanisms of HE in the brain tissue, we investigated the effects of PCS in rats on free radicals production and activity levels of antioxidant and prooxidant enzymes in mitochondria isolated from different brain areas. We found that O2·- production, activities of Mn-superoxide dismutase (Mn-SOD), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione transferase (GT), nitric oxide synthase (NOS), and levels of carbonylated proteins differed between the four brain regions both in the amount and response to PCS. In PCS rats, Mn-SOD activity in the cerebellum was significantly decreased, and remained unchanged in the neocortex, hippocampus and striatum compared with that in sham-operated animals. Among the four brain regions in control rats, the levels of the carbonyl groups in mitochondrial proteins were maximal in the cerebellum. 4 weeks after PCS, the content of carbonylated proteins were higher only in mitochondria of this brain region. Under control conditions, O2·- production by submitochondrial particles in the cerebellum was significantly higher than in other brain regions, but was significantly increased in each brain region from PCS animals. Indeed, the production of O2·- by submitochondrial particles correlated with mitochondrial ammonia levels in the four brain regions of control and PCS-animals. These findings are the first to suggest that in vivo levels of ammonia in the brain directly affect the rate of mitochondrial O2·- production.
Collapse
Affiliation(s)
- Elena A Kosenko
- Institute of Theoretical and Experimental Biophysics, Pushchino, Russia.
| | | | - Gubidat A Alilova
- Institute of Theoretical and Experimental Biophysics, Pushchino, Russia
| | - Carmina Montoliu
- Fundación Investigación Hospital Clínico, Instituto Investigación Sanitaria-INCLIVA, Valencia, Spain
| | - George E Barreto
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá D.C., Colombia; Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
| | - Gjumrakch Aliev
- GALLY International Biomedical Research Institute Inc., 7733 Louis Pasteur Drive, #330, San Antonio, TX 78229, USA; School of Health Science and Healthcare Administration, University of Atlanta, E. Johns Crossing, #175, Johns Creek, GA 30097, USA.
| | - Yury G Kaminsky
- Institute of Theoretical and Experimental Biophysics, Pushchino, Russia
| |
Collapse
|
5
|
Chepkova AN, Sergeeva OA, Haas HL. Alterations of corticostriatal plasticity by ammonium and rescue by green tea polyphenols. Arch Biochem Biophys 2013; 536:176-82. [DOI: 10.1016/j.abb.2013.02.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 01/31/2013] [Accepted: 02/05/2013] [Indexed: 01/22/2023]
|
6
|
Lauridsen MM, Thiele M, Kimer N, Vilstrup H. The continuous reaction times method for diagnosing, grading, and monitoring minimal/covert hepatic encephalopathy. Metab Brain Dis 2013; 28:231-4. [PMID: 23299303 DOI: 10.1007/s11011-012-9373-z] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2012] [Accepted: 12/21/2012] [Indexed: 02/07/2023]
Abstract
Existing tests for minimal/covert hepatic encephalopathy (m/cHE) are time- and expertise consuming and primarily useable for research purposes. An easy-to-use, fast and reliable diagnostic and grading tool is needed. We here report on the background, experience, and ongoing research regarding the continuous reaction times (CRT) method. The method has been in clinical use for decades in Denmark for the stated purpose. The method is a 10-minutes, computerised registration of a series of motor reaction times to an auditory stimulus, with results reported as the CRTindex (50 percentile/(90-10) percentile) as a parameter of reaction time variability. The index is a measure of alertness stability and is used to assess attention and cognition deficits. The CRTindex identifies half of patients in a Danish cohort with chronic liver disease, as having m/cHE, a normal value safely precludes HE, it has a broad outcome span reflecting the degree of brain impairment, it shows no learning effect, and it is independent on age and gender. The CRTindex is, therefore, a candidate tool for routine screening, detecting, grading, and monitoring m/cHE. Still, however, further methodological and clinical validation trials are required and are currently being conducted.
Collapse
Affiliation(s)
- M M Lauridsen
- Department of Gastroenterology and Hepatology, Hospital of South West Jutland, Finsensgade 35, 6700 Esbjerg, Denmark.
| | | | | | | |
Collapse
|
7
|
Wouters F, Wouters ATB, Watanabe TTN, Soares MP, Cruz CEF, Driemeier D. Pneumotoxicosis in Sheep Caused by Ingestion of Trema Micrantha. Vet Pathol 2013; 50:775-8. [DOI: 10.1177/0300985813478208] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Trema micrantha, a fast-growing tree distributed throughout the Americas, produces palatable leaves that have been associated with hepatic necrosis and acute death when consumed by livestock. This report describes fatal pulmonary disease of sheep triggered by consumption of Trema micrantha. Affected sheep had severe progressive dyspnea for a few days before death. Subcutaneous and mediastinal emphysema, reddened lungs, interalveolar septal thickening, and diffuse type II pneumocyte proliferation were the main pathological findings. After ingesting 77.5 and 102.5 g/kg (divided in 3 doses, at 30-day intervals) of T. micrantha leaves, 2 additional sheep developed the same condition. These findings indicate that T. micrantha toxicosis should be considered in the differential diagnosis of ovine respiratory disease.
Collapse
Affiliation(s)
- F. Wouters
- Departamento de Patologia Clínica, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul–UFRGS, Porto Alegre-RS, Brazil
| | - A. T. B. Wouters
- Departamento de Patologia Clínica, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul–UFRGS, Porto Alegre-RS, Brazil
| | - T. T. N. Watanabe
- Departamento de Patologia Clínica, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul–UFRGS, Porto Alegre-RS, Brazil
| | - M. P. Soares
- Laboratório Regional de Diagnóstico, Universidade Federal de Pelotas, Faculdade de Veterinária, Pelotas, Rio Grande do Sul, Brazil
| | - C. E. F. Cruz
- Departamento de Patologia Clínica, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul–UFRGS, Porto Alegre-RS, Brazil
| | - D. Driemeier
- Departamento de Patologia Clínica, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul–UFRGS, Porto Alegre-RS, Brazil
| |
Collapse
|
8
|
Pathogenesis of hepatic encephalopathy. Gastroenterol Res Pract 2012; 2012:642108. [PMID: 23316223 PMCID: PMC3534214 DOI: 10.1155/2012/642108] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2012] [Revised: 11/16/2012] [Accepted: 11/16/2012] [Indexed: 02/06/2023] Open
Abstract
Hepatic encephalopathy can be a serious complication of acute liver failure and chronic liver diseases, predominantly liver cirrhosis. Hyperammonemia plays the most important role in the pathogenesis of hepatic encephalopathy. The brain-blood barrier disturbances, changes in neurotransmission, neuroinflammation, oxidative stress, GABA-ergic or benzodiazepine pathway abnormalities, manganese neurotoxicity, brain energetic disturbances, and brain blood flow abnormalities are considered to be involved in the development of hepatic encephalopathy. The influence of small intestine bacterial overgrowth (SIBO) on the induction of minimal hepatic encephalopathy is recently emphasized. The aim of this paper is to present the current views on the pathogenesis of hepatic encephalopathy.
Collapse
|
9
|
Lauridsen MM, Grønbæk H, Næser EB, Leth ST, Vilstrup H. Gender and age effects on the continuous reaction times method in volunteers and patients with cirrhosis. Metab Brain Dis 2012; 27:559-65. [PMID: 22614824 DOI: 10.1007/s11011-012-9318-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Accepted: 05/09/2012] [Indexed: 12/11/2022]
Abstract
Minimal hepatic encephalopathy (MHE) is a metabolic brain disorder occurring in patients with liver cirrhosis. MHE lessens a patient's quality of life, but is treatable when identified. The continuous reaction times (CRT) method is used in screening for MHE. Gender and age effects on the CRT method are unknown and may confound the results. The aim of this study was to standardise the CRT method outcomes for age and gender effects. We studied 121 volunteers without known disease and 181 patients with cirrhosis by a CRT test. Reaction time to an auditory signal was measured 100 times, the 10th, 50th, and 90th reaction time percentiles were recorded, and the CRT index was calculated as the 50th percentile/(90th percentile-10th percentile), as a measure of intra-individual stability in reaction times. In volunteers, men reacted faster than women and their reaction times slowed with age. However, neither the gender nor the age effect was present regarding the CRT index. The patients with cirrhosis reacted slower and with a higher degree of instability than volunteers. Male patients reacted faster than female patients, and reaction times tended to slow with age. As among the volunteers, there was no gender or age effect on CRT index for the patients with cirrhosis. Age and gender influenced reaction times of both volunteers and patients with cirrhosis. The CRT index, however, was independent of age and gender in both groups. Screening of patients with cirrhosis using the CRT index, therefore, identifies brain dysfunction rather than effects of gender and age.
Collapse
Affiliation(s)
- Mette Munk Lauridsen
- Department of Gastroenterology and Hepatology, Hospital of Southern Jutland, 35 Finsensgade, 6700, Esbjerg, Denmark.
| | | | | | | | | |
Collapse
|
10
|
Chepkova AN, Selbach O, Haas HL, Sergeeva OA. Ammonia-induced deficit in corticostriatal long-term depression and its amelioration by zaprinast. J Neurochem 2012; 122:545-56. [PMID: 22639911 DOI: 10.1111/j.1471-4159.2012.07806.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hyperammonemia is a major pathophysiological factor in encephalopathies associated with acute and chronic liver failure. On mouse brain slice preparations, we analyzed the effects of ammonia on the characteristics of corticostriatal long-term depression (LTD) induced by electrical stimulation of cortical input or pharmacological activation of metabotropic glutamate receptors. Long exposure of neostriatal slices to ammonium chloride impaired the induction and/or expression of all studied forms of LTD. This impairment was reversed by the phosphodiesterase inhibitor zaprinast implying lowered cGMP signaling in LTD suppression. Polyphenols from green tea rescued short-term corticostriatal plasticity, but failed to prevent the ammonia-induced deficit of LTD. Zaprinast counteracts the ammonia-induced impairment of long-term corticostriatal plasticity and may thus improve fine motor skills and procedural learning in hepatic encephalopathy.
Collapse
Affiliation(s)
- Aisa N Chepkova
- Department of Neurophysiology, Medical Faculty, Heinrich-Heine-University, Dusseldorf, Germany
| | | | | | | |
Collapse
|
11
|
Lin WC, Hsu TW, Chen CL, Wu CW, Lu CH, Chen HL, Li SH, Yeh PY, Cheng YF, Lin CP. Connectivity of default-mode network is associated with cerebral edema in hepatic encephalopathy. PLoS One 2012; 7:e36986. [PMID: 22623966 PMCID: PMC3356373 DOI: 10.1371/journal.pone.0036986] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Accepted: 04/11/2012] [Indexed: 02/07/2023] Open
Abstract
Cerebral edema, a well-known feature of acute liver disease, can occur in cirrhotic patients regardless of hepatic encephalopathy (HE) and adversely affect prognosis. This study characterized and correlated functional HE abnormalities in the brain to cerebral edema using resting-state functional magnetic resonance imaging (rs-fMRI) and diffusion tensor imaging (DTI). Forty-one cirrhotic patients (16 without HE, 14 minimal HE, 11 overt HE) and 32 healthy controls were assessed. The HE grade in cirrhotic patients was evaluated by the West Haven criteria and neuro-psychological examinations. Functional connectivity correlation coefficient (fc-CC) of the default mode network (DMN) was determined by rs-fMRI, while the corresponding mean diffusivity (MD) was obtained from DTI. Correlations among inter-cortical fc-CC, DTI indices, Cognitive Ability Screening Instrument scores, and laboratory tests were also analyzed. Results showed that gradual reductions of HE-related consciousness levels, from "without HE" or "minimal HE" to "overt HE", correlated with decreased anterior-posterior fc-CC in DMN [F(4.415), p = 0.000)]. The MD values from regions with anterior-posterior fc-CC differences in DMN revealed significant differences between the overt HE group and other groups. Increased MD in this network was inversely associated with decreased fc-CC in DMN and linearly correlated with poor cognitive performance. In conclusion, cerebral edema can be linked to altered cerebral temporal architecture that modifies both within- and between-network connectivity in HE. Reduced fc-CC in DMN is associated with behavior and consciousness deterioration. Through appropriate targets, rs-fMRI technology may provide relevant supplemental information for monitoring HE and serve as a new biomarker for clinical diagnosis.
Collapse
Affiliation(s)
- Wei-Che Lin
- Department of Diagnostic Radiology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
- Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan
| | - Tun-Wei Hsu
- Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan
- Department of Diagnostic Radiology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Chao-Long Chen
- Department of Surgery, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Changwei W. Wu
- Institute of Biomedical Engineering, National Central University, Taoyuan, Taiwan
| | - Cheng-Hsien Lu
- Department of Neurology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Hsiu-Ling Chen
- Department of Diagnostic Radiology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
- Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan
| | - Shau-Hsuan Li
- Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Pin-Yang Yeh
- Instiute of Allied Health Science, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Psychiatry, Tsyr-Huey Mental Hospital, Kaohsiung, Taiwan
| | - Yu-Fan Cheng
- Department of Diagnostic Radiology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Ching-Po Lin
- Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan
- Lab for Brain Connectivity, Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan
| |
Collapse
|
12
|
Bandarra PM, Bezerra Júnior PS, Oliveira LGSD, Correa GL, Borba MR, Reck Júnior J, Cruz CEFD, Driemeier D. Intoxicação experimental por Trema micrantha (Cannabaceae) em equinos. PESQUISA VETERINARIA BRASILEIRA 2011. [DOI: 10.1590/s0100-736x2011001100009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
O objetivo desse estudo foi confirmar a toxidez e caracterizar os aspectos clínicos e patológicos da intoxicação por Trema micrantha em equinos. Três equinos, pôneis, com idade entre 2 e 7 anos consumiram espontaneamente folhas de T. micrantha em doses únicas de 30g/kg, 25g/ kg e 20g/kg. Os três animais adoeceram e evoluíram para morte. Outro equino recebeu 15 e 25g/kg da planta com intervalo de 30 dias entre as doses e não apresentou alteração clínica. Coletas diárias de sangue foram realizadas para análises bioquímicas. Os principais sinais clínicos apresentados foram apatia, desequilíbrios, dificuldade de deglutição, decúbito esternal, decúbito lateral, movimentos de pedalagem, coma e morte. Os três equinos afetados apresentaram elevação da atividade sérica de gama-glutamil transferase, dos níveis séricos de amônia e diminuição da glicemia. Esses animais foram necropsiados e fragmentos de diversos órgãos foram coletados para análise histopatológica e imuno-histoquímica. Os principais achados patológicos foram encontrados no fígado e no encéfalo dos três animais. O fígado apresentava, macroscopicamente, acentuação do padrão lobular; enquanto que, no encéfalo havia áreas amareladas na superfície de corte, mais evidentes na substância branca do cerebelo. Microscopicamente, o fígado apresentava tumefação hepatocelular, necrose de coagulação predominantemente centrolobular e hemorragia associada. No encéfalo, havia edema perivascular generalizado e astrócitos Alzheimer tipo II na substância cinzenta. Esses astrócitos apresentaram marcação fraca ou negativa na imuno-histoquímica anti-GFAP e marcação positiva do antígeno S-100. A dose letal mínima de folhas de T. micrantha estabelecida nesse experimento foi de 20g/kg. A ampla distribuição e palatabilidade desta planta, associadas à alta sensibilidade da espécie equina, constatada nesse experimento, reforçam a importância da planta em casos acidentais de intoxicação em equinos.
Collapse
|
13
|
Chepkova A, Yanovsky E, Parmentier R, Ohtsu H, Haas HL, Lin JS, Sergeeva OA. Histamine Receptor Expression, Hippocampal Plasticity and Ammonia in Histidine Decarboxylase Knockout Mice. Cell Mol Neurobiol 2011; 32:17-25. [DOI: 10.1007/s10571-011-9730-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Accepted: 06/14/2011] [Indexed: 10/18/2022]
|
14
|
Lauridsen MM, Jepsen P, Vilstrup H. Critical flicker frequency and continuous reaction times for the diagnosis of minimal hepatic encephalopathy: a comparative study of 154 patients with liver disease. Metab Brain Dis 2011; 26:135-9. [PMID: 21484318 DOI: 10.1007/s11011-011-9242-1] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Accepted: 03/31/2011] [Indexed: 12/30/2022]
Abstract
Minimal hepatic encephalopathy (MHE) is intermittently present in up to 2/3 of patients with chronic liver disease. It impairs their daily living and can be treated. However, there is no consensus on diagnostic criteria except that psychometric methods are required. We compared two easy-to-perform reproducible bedside methods: the critical flicker frequency (CFF) and continuous reaction times (CRT) tests. A CFF <39 Hz and CRT-index <1.9 (index: the ratio 50/(90 minus 10) percentiles of reaction times) indicates cerebral dysfunction. 154 patients with acute or chronic liver disease with out overt hepatic encephalopathy (HE) underwent both tests at the same occasion. Both tests were abnormal in 20% of the patients and both tests were normal in 40% of the patients. In more than 1/3 the two tests were not in agreement as CFF classified 32% and CRT-index classified 48% of the patients as having MHE (p < 0.005). The two tests were weakly linearly correlated (r(2) = 0.14, p < 0.001) and neither test correlated with the metabolic liver function measured by the Galactose Elimination Capacity (GEC), nor with the blood ammonia concentration. Both tests identified a large fraction of the patients as having MHE and cleared only 40%. The two tests did not show concordant results, likely because they describe different aspects of MHE: the CFF gives a measure of astrocytic metabolic state and hence pathogenic aspects of MHE, whereas the CRT measures a composite key performance, viz. the ability of reacting appropriately to a sensory stimulus. The choice of test depends on the information needed in the clinical and scientific care and study of the patients.
Collapse
Affiliation(s)
- Mette Munk Lauridsen
- Department of Medicine V (Hepatology and Gastroenterology), Aarhus University Hospital, Aarhus, Denmark.
| | | | | |
Collapse
|
15
|
Bandarra PM, Pavarini SP, Raymundo DL, Corrêa AMR, Pedroso PMO, Driemeier D. Trema micrantha toxicity in horses in Brazil. Equine Vet J 2010; 42:456-9. [PMID: 20636784 DOI: 10.1111/j.2042-3306.2010.00035.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
After ingesting green leaves of T. micrantha, 2 horses showed apathy, locomotor deficit, blindness, recumbency, paddling, coma and death. The main gross findings were scattered haemorrhages, enhanced lobular pattern of the liver, and cerebral oedema. Histological changes included disseminated haemorrhages, massive hepatocellular necrosis, neuronal degeneration, Alzheimer type II astrocytes and cerebral perivascular oedema. Clinicopathological findings which were comparable with those observed in Trema micrantha poisoned ruminants, associated with epidemiological evidence suggested the diagnosis.Trema micrantha poisoning should be evaluated as a possible cause in the diagnosis of equine hepatopathy and occasional secondary encephalopathy.
Collapse
Affiliation(s)
- P M Bandarra
- Departmento de Patologia Clínica, Faculdade de Veterinária, UFRGS. Porto Alegre-RS, Brazil
| | | | | | | | | | | |
Collapse
|
16
|
McPhail MJW, Bajaj JS, Thomas HC, Taylor-Robinson SD. Pathogenesis and diagnosis of hepatic encephalopathy. Expert Rev Gastroenterol Hepatol 2010; 4:365-78. [PMID: 20528123 DOI: 10.1586/egh.10.32] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Hepatic encephalopathy (HE) is a common and potentially devastating neuropsychiatric complication of acute liver failure and cirrhosis. Even in its mildest form, minimal HE (MHE), the syndrome significantly impacts daily living and heralds progression to overt HE. There is maturity in the scientific understanding of the cellular processes that lead to functional and structural abnormalities in astrocytes. Hyperammonemia and subsequent cell swelling is a key pathophysiological abnormality, but this aspect alone is insufficient to fully explain the complex neurotransmitter abnormalities that may be observable using sophisticated imaging techniques. Inflammatory cytokines, reactive oxygen species activation and the role of neurosteroids on neurotransmitter binding sites are emerging pathological lines of inquiry that have yielded important new information on the processes underlying HE and offer promise of future therapeutic targets. Overt HE remains a clinical diagnosis and the neurophysiological and imaging modalities used in research studies have not transferred successfully to the clinical situation. MHE is best characterized by psychometric evaluation, but these tests can be lengthy to perform and require specific expertise to interpret. Simpler computer-based tests are now available and perhaps offer an opportunity to screen, diagnose and monitor MHE in a clinical scenario, although large-scale studies comparing the different techniques have not been undertaken. There is a discrepancy between the depth of understanding of the pathophysiology of HE and the translation of this understanding to a simple, easily understood diagnostic and longitudinal marker of disease. This is a present area of focus for the management of HE.
Collapse
Affiliation(s)
- Mark J W McPhail
- Hepatology Section, Department of Medicine, 10th Floor QEQM Wing, St Mary's Hospital Campus, Imperial College London, South Wharf Street, London W2 1NY, UK
| | | | | | | |
Collapse
|
17
|
Márquez-Aguirre A, Canales-Aguirre A, Gómez-Pinedo U, Gálvez-Gastélum F. Aspectos moleculares de la encefalopatía hepática. Neurologia 2010. [DOI: 10.1016/j.nrl.2009.12.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
|
18
|
McPhail MJW, Taylor-Robinson SD. The role of magnetic resonance imaging and spectroscopy in hepatic encephalopathy. Metab Brain Dis 2010; 25:65-72. [PMID: 20221679 DOI: 10.1007/s11011-010-9171-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2009] [Accepted: 01/28/2010] [Indexed: 01/22/2023]
Abstract
Hepatic encephalopathy (HE) is a diverse manifestation of acute and chronic liver failure, ranging from cognitive impairment, only detectable on psychometric evaluation through to confusion, coma and death from cerebral oedema. While there is widespread acceptance of its importance, there is little consensus on how best to diagnose and monitor HE. Clinical descriptions, psychometric testing, electroencephalography and magnetic resonance (MR) imaging (and lately, MR spectroscopy) have all been proposed. MR techniques, in contrast to other modalities, have the benefit of objectivity and of being able to interrogate the brain directly with respect to changes in brain size, function and the metabolic disturbances thought to underlie HE, particularly in the context of astrocyte swelling. Modern clinical MRI scanners with multinuclear MR spectroscopy capabilities and brain mapping software can demonstrate structural and functional cellular changes using volumetric MRI, magnetization transfer MRI, diffusion-weighting MRI, functional MRI with oxygenation measurements and in vivo and in vitro (1)H and (31)P MR spectroscopy. This review describes the relative merits of these techniques and provides guidance on the directions for future research and translation into clinical practice.
Collapse
Affiliation(s)
- Mark J W McPhail
- Liver and Anti-Viral Centre, Department of Hepatology, Division of Medicine, Imperial College London, 10th Floor QEQM Building, St Mary's Hospital Campus, South Wharf Road, London, W2 1NY, United Kingdom
| | | |
Collapse
|
19
|
Márquez-Aguirre A, Canales-Aguirre A, Gómez-Pinedo U, Gálvez-Gastélum F. Molecular aspects of hepatic encephalopathy. NEUROLOGÍA (ENGLISH EDITION) 2010. [DOI: 10.1016/s2173-5808(10)70048-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
|
20
|
Sergeeva OA, Fleischer W, Chepkova AN, Warskulat U, Häussinger D, Siebler M, Haas HL. GABAA-receptor modification in taurine transporter knockout mice causes striatal disinhibition. J Physiol 2007; 585:539-48. [PMID: 17962336 DOI: 10.1113/jphysiol.2007.141432] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The Striatum is involved in the regulation of movements and motor skills. We have shown previously, that the osmolyte and neuromodulator taurine plays a role in striatal plasticity. We demonstrate now that hereditary taurine deficiency in taurine-transporter knock-out (TAUT KO) mice results in disinhibition of striatal network activity, which can be corrected by taurine supplementation. Modification of GABAA but not glycine receptors (taurine is a ligand for both receptor types) underlies this disinhibition. Whole-cell recordings from acutely isolated as well as cultured striatal neurons revealed a decreased agonist sensitivity of the GABAA receptor in TAUT KO neurons in the absence of changes in the maximal GABA-evoked current amplitude. The striatal GABA level in TAUT KO mice was unchanged. The amplitude enhancement of spontaneous IPSCs by zolpidem was stronger in TAUT KO than in wild-type (WT) animals. Tonic inhibition was absent in striatal neurons under control conditions but was detected after incubation with the GABA-transaminase inhibitor vigabatrin: bicuculline induced a larger shift of baseline current in WT as compared to TAUT KO neurons. Lack of taurine leads to reduced sensitivity of synaptic and extrasynaptic GABAA receptors and consequently to disinhibition. These findings help in understanding neuropathologies accompanied by the loss of endogenous taurine, for instance in hepatic encephalopathy.
Collapse
Affiliation(s)
- O A Sergeeva
- Department of Neurophysiology, Heinrich-Heine-Universität, Physiology II, POB 101007, D-40001 Düsseldorf, Germany.
| | | | | | | | | | | | | |
Collapse
|
21
|
Johns IC, Del Piero F, Wilkins PA. Hepatic encephalopathy in a pregnant mare: identification of histopathological changes in the brain of a mare and fetus. Aust Vet J 2007; 85:337-40. [PMID: 17685983 DOI: 10.1111/j.1751-0813.2007.00144.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An 11-year-old Thoroughbred broodmare was evaluated for suspected hepatic dysfunction. Clinical signs of hepatic encephalopathy were evident at admission. Hepatic ultrasonographic evaluation revealed an increase in hepatic size, rounded borders and normal echogenicity. There was no evidence of cholelithiasis or bile duct distention. Increased activity of hepatic enzymes, increased bile acid and bilirubin concentration and an increased ammonia concentration were supportive of a diagnosis of hepatic disease and hepatic encephalopathy. Histopathological evaluation of a liver biopsy specimen was consistent with chronic active hepatitis. The mare was treated with intravenous fluids and antimicrobials, pentoxyfilline, branched-chain amino acids and dietary manipulation. Clinical improvement was observed initially; however, 3 weeks later, deterioration in the mare's condition necessitated euthanasia. Pathological lesions at necropsy were restricted to the liver and brain. The liver was diffusely firm with a prominent reticular pattern on the cut surface. A large choledocholith was present in the main bile duct of the left liver lobe. Histopathological examination of the liver revealed severe fibrosis, with hyperplastic bile ducts and mononuclear and neutrophilic inflammation. Pathological changes consistent with hepatic encephalopathy, (Alzheimer type II cells), were evident in the cerebrum of both the mare and the fetus.
Collapse
Affiliation(s)
- I C Johns
- Department of Clinical Studies, University of Pennsylvania, Kennett Square, PA, USA.
| | | | | |
Collapse
|
22
|
Chepkova AN, Sergeeva OA, Haas HL. Taurine rescues hippocampal long-term potentiation from ammonia-induced impairment. Neurobiol Dis 2006; 23:512-21. [PMID: 16766203 DOI: 10.1016/j.nbd.2006.04.006] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2005] [Revised: 04/11/2006] [Accepted: 04/12/2006] [Indexed: 11/19/2022] Open
Abstract
Hyperammonemia, a major pathophysiological factor in hepatic encephalopathy, impairs long-term potentiation (LTP) of synaptic transmission, a cellular model of learning and memory, in the hippocampus. We have now studied the protective action of taurine on this paradigm by analyzing LTP characteristics in mouse hippocampal slices treated with ammonium chloride (1 mM) in the presence of taurine (1 mM), an ubiquitous osmolyte, antioxidant, and neuromodulator, as well as other substances with such properties. Ammonia-treated slices displayed a significant impairment of LTP maintenance. Taurine and the mitochondrial enhancer l-carnitine, but not the antioxidants (ascorbate, carnosine, and the novel compound GVS-111) or the osmolyte betaine prevented this impairment. The protective effect of taurine was preserved under the blockade of inhibitory GABA(A) and glycine receptors. It is suggested that taurine may rescue the mechanisms of hippocampal synaptic plasticity by improving mitochondrial function under hyperammonemic conditions.
Collapse
Affiliation(s)
- Aisa N Chepkova
- Department of Neurophysiology, Heinrich-Heine University, POB 101007, D-40001 Düsseldorf, Germany
| | | | | |
Collapse
|
23
|
Vergara-Gómez M, Flavià-Olivella M, Gil-Prades M, Dalmau-Obrador B, Córdoba-Cardona J. [Diagnosis and treatment of hepatic encephalopathy in Spain: results of a survey of hepatologists]. GASTROENTEROLOGIA Y HEPATOLOGIA 2006; 29:1-6. [PMID: 16393622 DOI: 10.1157/13083245] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
INTRODUCTION Hepatic encephalopathy is a common complication of cirrhosis. Recent studies have challenged the efficacy of nonabsorbable disaccharides and have reported that protein restriction may pose risks to patients with cirrhosis and hepatic encephalopathy. AIM To determine the diagnostic and therapeutic practices of physicians treating patients with hepatic encephalopathy. MATERIAL AND METHODS We designed a 20-item questionnaire, which was mailed to the members of the Spanish Society for the Study of the Liver. RESULTS We received 128 questionnaires, completed by physicians with wide clinical experience. They reported that the most common precipitating factors in episodic encephalopathy were infections (22%), diuretics (21%), and gastrointestinal bleeding (21%). The usual treatment of episodic encephalopathy was administration of nonabsorbable disaccharides (90%) and protein restriction (52%). Patients with chronic encephalopathy were also usually treated with nonabsorbable disaccharides (94%) and protein restriction (40%). Fifty-nine percent of the hepatologists never carried out neurophysiologic or neuropsychologic assessment for the diagnosis of minimal hepatic encephalopathy. CONCLUSION Although their efficacy has been questioned, nonabsorbable disaccharides and protein restriction are the most commonly prescribed treatments for hepatic encephalopathy. Future studies are needed to assess the efficacy and risks of these treatments. Most hepatologists never assess minimal hepatic encephalopathy in patients with cirrhosis.
Collapse
Affiliation(s)
- M Vergara-Gómez
- Unitat de Malalties Digestives, Corporació Parc Taulí, Universitat Autònoma de Barcelona, Sabadell, Barcelona, Spain.
| | | | | | | | | |
Collapse
|
24
|
Abstract
Hepatic encephalopathy (HE) is a complicated disorder, the pathophysiology of which remains to be fully understood. This article reviews the current main theories including the potential involvement of ammonia, gamma-aminobutyric acid (GABA)/benzodiazipines and false neurotransmitters. Each theory is critically examined with the evidence for each reviewed carefully, and the potential relationship of ammonia to the remaining two theories explored. Known preciptating factors of HE are also considered as evidence. The conclusions drawn from the evidence provided indicate the large role played by ammonia and suggest that this may be the key to understanding HE as science progresses.
Collapse
|
25
|
Benarroch EE. Neuron-astrocyte interactions: partnership for normal function and disease in the central nervous system. Mayo Clin Proc 2005; 80:1326-38. [PMID: 16212146 DOI: 10.4065/80.10.1326] [Citation(s) in RCA: 212] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Interactions between neurons and astrocytes are critical for signaling, energy metabolism, extracellular ion homeostasis, volume regulation, and neuroprotection in the central nervous system. Astrocytes face the synapses, send end-foot processes that enwrap the brain capillaries, and form an extensive network interconnected by gap junctions. Astrocytes express several membrane proteins and enzymes that are critical for uptake of glutamate at the synapses, ammonia detoxification, buffering of extracellular K+, and volume regulation. They also participate in detection, propagation, and modulation of excitatory synaptic signals, provide metabolic support to the active neurons, and contribute to functional hyperemia in the active brain tissue. Disturbances of these neuron-astrocyte interactions are likely to play an important role in neurologic disorders including cerebral ischemia, neurodegeneration, migraine, cerebral edema, and hepatic encephalopathy.
Collapse
Affiliation(s)
- Eduardo E Benarroch
- Department of Neurology, Mayo Clinic College of Medicine, 200 First St SW, Rochester, MN 55905, USA.
| |
Collapse
|
26
|
Rovira A. Resonancia magnética craneal en la encefalopatía hepática. RADIOLOGIA 2005. [DOI: 10.1016/s0033-8338(05)72828-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
27
|
Sergeeva OA, Schulz D, Doreulee N, Ponomarenko AA, Selbach O, Borsch E, Kircheis G, Huston JP, Häussinger D, Haas HL. Deficits in cortico-striatal synaptic plasticity and behavioral habituation in rats with portacaval anastomosis. Neuroscience 2005; 134:1091-8. [PMID: 16039790 DOI: 10.1016/j.neuroscience.2005.05.031] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2005] [Revised: 05/13/2005] [Accepted: 05/17/2005] [Indexed: 11/30/2022]
Abstract
Hepatic encephalopathy is characterized by disturbances of motor and cognitive functions involving the basal ganglia. So far no standards for assessment of neuropsychiatric abnormalities (disorders of sleep, mood, anxiety and personality) in subclinical hepatic encephalopathy have been defined. Using an animal model of mild (subclinical) hepatic encephalopathy we investigated now striatum-related behaviors and cortico-striatal synaptic plasticity in rats 2 months after introduction of a portacaval shunt and sham-operated matched controls. In a novel open field portacaval shunt rats displayed less locomotor activity; unlike controls they also showed no habituation to the field and no recall of the field environment after 24 h, indicative of cognitive deficit. The elevated-plus maze test indicated no differences in fear/anxiety in the portacaval shunt animals. Tetanic stimulation of cortical afferents in magnesium-free solution evoked an N-methyl-D-aspartate-dependent long-term potentiation in sham-operated animals. In portacaval shunt animals long-term potentiation was significantly impaired. Histamine, a potent modulator of cortico-striatal transmission, induced a larger long-term depression of field potentials in control compared with portacaval shunt rats. In conclusion, a combination of electrophysiological and behavioral approaches has revealed functional changes in cortico-striatal transmission. These data are relevant for understanding the mechanisms of motor and cognitive dysfunctions in hepatic encephalopathy patients and for the development of precise psychometric tests, evaluating cognitive deficits in subclinical hepatic encephalopathy.
Collapse
Affiliation(s)
- O A Sergeeva
- Department of Neurophysiology, Heinrich-Heine-Universität, Düsseldorf, Germany.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Abstract
Tumor cell targeted therapies, by induction or enhancement of apoptosis, constitute recent promising approaches achieving more specific anti-tumor efficacy. The peripheral benzodiazepine receptor (PBR), which belongs to the permeability transition pore (PTP), the central regulatory complex of apoptosis, is a potential target. A number of findings argue in favor of the development of PBR targeting approaches: (i) overexpression of PBR has been described in a large range of human cancers, (ii) PTP-mediated regulation of programmed cell death is an apoptotic-inducing factor-independent check-point that could be modulated by various conventional cancer therapies, and (iii) PBR ligation enhances apoptosis induction in many types of tumors and reverses Bcl-2 cytoprotective effects. Altogether, these observations support the use of PBR-directed drugs, particularly PBR ligands such as Ro5-4864, in the treatment of human cancers.
Collapse
Affiliation(s)
- Didier Decaudin
- Department of Clinical Hematology, Institut Curie, Paris, France.
| |
Collapse
|
29
|
Mackenzie B, Erickson JD. Sodium-coupled neutral amino acid (System N/A) transporters of the SLC38 gene family. Pflugers Arch 2004; 447:784-95. [PMID: 12845534 DOI: 10.1007/s00424-003-1117-9] [Citation(s) in RCA: 377] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2003] [Revised: 05/16/2003] [Accepted: 05/16/2003] [Indexed: 01/04/2023]
Abstract
The sodium-coupled neutral amino acid transporters (SNAT) of the SLC38 gene family resemble the classically-described System A and System N transport activities in terms of their functional properties and patterns of regulation. Transport of small, aliphatic amino acids by System A subtypes (SNAT1, SNAT2, and SNAT4) is rheogenic and pH sensitive. The System N subtypes SNAT3 and SNAT5 also countertransport H(+), which may be key to their operation in reverse, and have narrower substrate profiles than do the System A subtypes. Glutamine emerges as a favored substrate throughout the family, except for SNAT4. The SLC38 transporters undoubtedly play many physiological roles including the transfer of glutamine from astrocyte to neuron in the CNS, ammonia detoxification and gluconeogenesis in the liver, and the renal response to acidosis. Probing their regulation has revealed additional roles, and recent work has considered SLC38 transporters as therapeutic targets in neoplasia.
Collapse
Affiliation(s)
- Bryan Mackenzie
- Membrane Biology Program and Renal Division, Brigham and Women's Hospital and Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA.
| | | |
Collapse
|