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Oria M, Tatu RR, Lin CY, Peiro JL. In Vivo Evaluation of Novel PLA/PCL Polymeric Patch in Rats for Potential Spina Bifida Coverage. J Surg Res 2019; 242:62-69. [PMID: 31071606 DOI: 10.1016/j.jss.2019.04.035] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 02/20/2019] [Accepted: 04/09/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND Current therapeutic materials for spina bifida repair showed a limited number of options in the market, and none of them have all the requirements as the ideal patch. In fact, sometimes the surgical procedures pose substantial challenges using different patches to fully cover the spina bifida lesion. For this purpose, a tailored patch made of poly (L-lactic acid) and poly (ε-caprolactone) blend was designed and validated in vitro to accomplish all these requirements but was never tested in vivo. MATERIAL AND METHODS In our present study, the designed patch was analyzed in terms of rejection from the animal when implanted subcutaneously and as a dural substitute in the spinal cord. Inflammatory reaction (Iba1), astrogliosis (GFAP), was analyzed and functional interaction with spinal cord tissue assessing the (%motor-evoked potentials /compound motor action potential) by electrophysiology. RESULTS No evidence of adverse or inflammatory reactions was observed in both models of subcutaneous implantation, neither in the neural tissue as a dural substitute. No signs of astrogliosis in the neural tissue were observed, and no functional alteration with improvement of the motor-evoked potential's amplitude was detected after 4 wk of implantation as a dural substitute in the rat spinal cord. CONCLUSIONS Designed patch used as a dural substitute will apparently not produce inflammation, scar formation, or tethering cord and not induce any adverse effect on regular functions of the spinal cord. Further studies are needed to evaluate potential improvements of this novel polymeric patch in the spinal cord regeneration using spina bifida models.
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Affiliation(s)
- Marc Oria
- Division of Pediatric General and Thoracic Surgery, Center for Fetal and Placental Research, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, Ohio
| | - Rigwed R Tatu
- Department of Biomedical Engineering, Structural Tissue Evaluation and Engineering Laboratory, University of Cincinnati, Cincinnati, Ohio
| | - Chia-Ying Lin
- Department of Biomedical Engineering, Structural Tissue Evaluation and Engineering Laboratory, University of Cincinnati, Cincinnati, Ohio
| | - Jose L Peiro
- Division of Pediatric General and Thoracic Surgery, Center for Fetal and Placental Research, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, Ohio.
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2
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García-Lezana T, Oria M, Romero-Giménez J, Bové J, Vila M, Genescà J, Chavarria L, Cordoba J. Cerebellar neurodegeneration in a new rat model of episodic hepatic encephalopathy. J Cereb Blood Flow Metab 2017; 37:927-937. [PMID: 27154504 PMCID: PMC5363476 DOI: 10.1177/0271678x16649196] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Hepatic encephalopathy has traditionally been considered a reversible disorder. However, recent studies suggested that repeated episodes of hepatic encephalopathy cause persistent impairment leading to neuronal loss. The aims of our study were the development of a new animal model that reproduces the course of episodic hepatic encephalopathy and the identification of neurodegeneration evidences. Rats with portacaval anastomosis underwent simulated episodes of hepatic encephalopathy, triggered by the regular administration of ammonium acetate, and/or lipopolysaccharide. The neurological status was assessed and neuronal loss stereologically quantified in motor areas. During the simulated episodes, ammonia induced reversible motor impairment in portacaval anastomosis rats. In cerebellum, stereology showed a reduction in Purkinje cell population in portacaval anastomosis and PCA+NH3 groups and morphological changes. An increase in astrocyte size in PCA+NH3 group and activated microglia in groups treated with ammonium acetate and/or lipopolysaccharide was observed. A modulation of neurodegeneration-related genes and the presence of apoptosis in Bergmann glia were observed. This new animal model reproduces the clinical course of episodic hepatic encephalopathy when ammonia is the precipitant factor and demonstrates the existence of neuronal loss in cerebellum. The persistence of over-activated microglia and reactive astrocytes could participate in the apoptosis of Bergmann glia and therefore Purkinje cell degeneration.
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Affiliation(s)
- Teresa García-Lezana
- 1 Liver Unit, Institut de Recerca Valld'Hebron (VHIR), Hospital Universitari Vall d'Hebron, Barcelona, Spain
- 2 Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Instituto de Salud Carlos III, Madrid, Spain
- 3 Departament Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Marc Oria
- 1 Liver Unit, Institut de Recerca Valld'Hebron (VHIR), Hospital Universitari Vall d'Hebron, Barcelona, Spain
- 2 Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Instituto de Salud Carlos III, Madrid, Spain
- 3 Departament Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain
- 4 Center for Fetal, Cellular and Mollecular Therapy, Division of Pediatric General and Thoracic Surgery, Cincinnati Children's Hospital Medical Center (CCHMC), OH, US
| | - Jordi Romero-Giménez
- 1 Liver Unit, Institut de Recerca Valld'Hebron (VHIR), Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Jordi Bové
- 5 Neurodegenerative Diseases Research Group, Institut de Recerca Valld'Hebron (VHIR) - Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas, Barcelona, Spain
| | - Miquel Vila
- 5 Neurodegenerative Diseases Research Group, Institut de Recerca Valld'Hebron (VHIR) - Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas, Barcelona, Spain
- 6 Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, Spain
- 7 Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain
| | - Joan Genescà
- 1 Liver Unit, Institut de Recerca Valld'Hebron (VHIR), Hospital Universitari Vall d'Hebron, Barcelona, Spain
- 2 Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Instituto de Salud Carlos III, Madrid, Spain
- 3 Departament Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Laia Chavarria
- 1 Liver Unit, Institut de Recerca Valld'Hebron (VHIR), Hospital Universitari Vall d'Hebron, Barcelona, Spain
- 2 Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Instituto de Salud Carlos III, Madrid, Spain
- 3 Departament Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Juan Cordoba
- 1 Liver Unit, Institut de Recerca Valld'Hebron (VHIR), Hospital Universitari Vall d'Hebron, Barcelona, Spain
- 2 Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Instituto de Salud Carlos III, Madrid, Spain
- 3 Departament Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain
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3
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Complete rat spinal cord transection as a faithful model of spinal cord injury for translational cell transplantation. Sci Rep 2015; 5:9640. [PMID: 25860664 PMCID: PMC5381701 DOI: 10.1038/srep09640] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 03/09/2015] [Indexed: 01/09/2023] Open
Abstract
Spinal cord injury (SCI) results in neural loss and consequently motor and sensory impairment below the injury. There are currently no effective therapies for the treatment of traumatic SCI in humans. Various animal models have been developed to mimic human SCI. Widely used animal models of SCI are complete or partial transection or experimental contusion and compression, with both bearing controversy as to which one more appropriately reproduces the human SCI functional consequences. Here we present in details the widely used procedure of complete spinal cord transection as a faithful animal model to investigate neural and functional repair of the damaged tissue by exogenous human transplanted cells. This injury model offers the advantage of complete damage to a spinal cord at a defined place and time, is relatively simple to standardize and is highly reproducible.
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Amodio P, Montagnese S. Clinical neurophysiology of hepatic encephalopathy. J Clin Exp Hepatol 2015; 5:S60-8. [PMID: 26041960 PMCID: PMC4442865 DOI: 10.1016/j.jceh.2014.06.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 06/05/2014] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND/OBJECTIVES Hepatic encephalopathy (HE) has relevant impact on the quality of life of patients and their caregivers and causes relevant costs because of hospitalizations and work days lost. Its quantification is important to perform adequate clinical trials on this relevant complication of cirrhosis and portal-systemic shunting. Clinical neurophysiology, which detects functional alterations of the nervous system, has been applied to the study of HE for over 60 years. This review aims at summarizing and clarifying the role of neurophysiologic techniques in the study of HE. METHODS A narrative review was performed aiming at interpreting the cited papers and the techniques on the basis of their physiological and pathophysiological meaning. RESULTS The potential role of EEG, quantified EEG, evoked potentials-both exogenous, endogenous and motor-have been clarified to the reader that may be unfamiliar with neurophysiology. CONCLUSIONS The EEG, reflecting the oscillatory changes of neural network is the preferable tool to detect and monitor HE, with the exception of its most severe stage, when EEG flattens. SSEP and MEP have indication to detect and monitor transmission alterations that are likely related to myelin changes and microedema.
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Key Words
- BAEPs, brainstem acoustic evoked potentials
- EEG
- EEG, electroencephalogram
- EPs, evoked potentials
- ERPs, event related potentials
- HE, hepatic encephalopathy
- MEG, magnetoencephalogram
- MEPs, motor evoked potentials
- SSEPs, somatosensory evoked potential
- VEPs, visual evoked potentials
- cirrhosis
- evoked potentials
- fVPS, flash visual evoked potentials
- hepatic encephalopathy
- neurophysiology
- pVEPs, pattern reversal visual evoked potentials
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Affiliation(s)
- Piero Amodio
- Address for correspondence: Piero Amodio, Department of Medicine, DIMED, University of Padua, via Giustiniani, 2; 35128 Padova, Italy. Fax: +39 049 7960903.
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Marques TG, Chaib E, da Fonseca JH, Lourenço ACR, Silva FD, Ribeiro MAF, Galvão FHF, D'Albuquerque LAC. Review of experimental models for inducing hepatic cirrhosis by bile duct ligation and carbon tetrachloride injection. Acta Cir Bras 2013; 27:589-94. [PMID: 22850713 DOI: 10.1590/s0102-86502012000800013] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Accepted: 06/21/2012] [Indexed: 01/03/2023] Open
Abstract
PURPOSE To present a review about a comparative study of bile duct ligation versus carbon tetrachloride Injection for inducing experimental liver cirrhosis. METHODS This research was made through Medline/PubMed and SciELO web sites looking for papers on the content "induction of liver cirrhosis in rats". We have found 107 articles but only 30 were selected from 2004 to 2011. RESULTS The most common methods used for inducing liver cirrhosis in the rat were administration of carbon tetrachloride (CCl4) and bile duct ligation (BDL). CCl4 has induced cirrhosis from 36 hours to 18 weeks after injection and BDL from seven days to four weeks after surgery. CONCLUSION For a safer inducing cirrhosis method BDL is better than CCl4 because of the absence of toxicity for researches and shorter time for achieving it.
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Coll M, Rodriguez S, Raurell I, Ezkurdia N, Brull A, Augustin S, Guardia J, Esteban R, Martell M, Genescà J. Droxidopa, an oral norepinephrine precursor, improves hemodynamic and renal alterations of portal hypertensive rats. Hepatology 2012; 56:1849-60. [PMID: 22610782 DOI: 10.1002/hep.25845] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Accepted: 05/07/2012] [Indexed: 12/25/2022]
Abstract
UNLABELLED We aimed to evaluate the effects of droxidopa (an oral synthetic precursor of norepinephrine) on the hemodynamic and renal alterations of portal hypertensive rats. Sham, portal vein-ligated (PVL), and 4-week biliary duct-ligated (BDL) rats received a single oral dose of droxidopa (25-50 mg/kg) or vehicle and hemodynamic parameters were monitored for 2 hours. Two groups of BDL and cirrhotic rats induced by carbon tetrachloride (CCl(4) ) were treated for 5 days with droxidopa (15 mg/kg, twice daily, orally); hemodynamic parameters and blood and urinary parameters were assessed. The droxidopa effect on the Rho kinase (RhoK) / protein kinase B (AKT) / endothelial nitric oxide synthase (eNOS) pathways was analyzed by western blot in superior mesenteric artery (SMA). The acute administration of droxidopa in PVL and BDL rats caused a significant and maintained increase in arterial pressure and mesenteric arterial resistance, with a significant decrease of mesenteric arterial and portal blood flow, without changing portal pressure and renal blood flow. Two-hour diuresis greatly increased. Carbidopa (DOPA decarboxylase inhibitor) blunted all effects of droxidopa. Chronic droxidopa therapy in BDL rats produced the same beneficial hemodynamic effects observed in the acute study, did not alter liver function parameters, and caused a 50% increase in 24-hour diuresis volume (7.4 ± 0.9 mL/100g in BDL vehicle versus 11.8 ± 2.5 mL/100g in BDL droxidopa; P = 0.01). Droxidopa-treated rats also showed a decreased ratio of p-eNOS/eNOS and p-AKT/AKT and increased activity of RhoK in SMA. The same chronic treatment in CCl(4) rats caused similar hemodynamic effects and produced significant increases in diuresis volume and 24-hour natriuresis (0.08 ± 0.02 mmol/100g in CCl(4) vehicle versus 0.23 ± 0.03 mmol/100g in CCl(4) droxidopa; P = 0.014). CONCLUSION Droxidopa might be an effective therapeutic agent for hemodynamic and renal alterations of liver cirrhosis and should be tested in cirrhosis patients.
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Affiliation(s)
- Mar Coll
- Department of Internal Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
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7
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Leclère FM, Germain MA, Lewbart GA, Unglaub F, Mordon S, Louis D. Microsurgery in liver research: end-to-side portocaval microanastomoses in dogfish. Clin Res Hepatol Gastroenterol 2011; 35:650-4. [PMID: 21821480 DOI: 10.1016/j.clinre.2011.06.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Revised: 06/18/2011] [Accepted: 06/24/2011] [Indexed: 02/04/2023]
Abstract
BACKGROUND The use of an operating microscope in animal liver surgery has made it possible to obtain new experimental models. The goal of this prospective animal study is to present our experience with dogfish portocaval microanastomoses. METHODS Nineteen portocaval microanastomoses were performed in dogfish. The end-to-side anastomoses were accomplished using continuous 11-0 sutures. The diameter of the vessels and time required for the anastomoses were measured. A patency test and its outcome were also prospectively evaluated at the time of anastomoses and then 3 and 6 months after. RESULTS The mean vessel diameter was 2.5 ± 0.2mm. The mean anastomosis time was 14 ± 1.5 min. The anastomoses patency rate was 100% at the time of surgery. A postoperative control performed after 3 and 6 months showed a partial stenosis in three animals. CONCLUSION The dogfish appears to be a reliable experimental model in liver research. Moreover, this technique could be used for microsurgical training.
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Affiliation(s)
- F M Leclère
- Inserm U703, Laboratory of Microsurgery, Lille University Hospital, 152 rue du Dr-Yersin, 59120 Lille-Loos, France.
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8
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Méndez M, Méndez-López M, López L, Aller MA, Arias J, Arias JL. Portosystemic hepatic encephalopathy model shows reversal learning impairment and dysfunction of neural activity in the prefrontal cortex and regions involved in motivated behavior. J Clin Neurosci 2011; 18:690-4. [PMID: 21371891 DOI: 10.1016/j.jocn.2010.09.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Revised: 09/15/2010] [Accepted: 09/22/2010] [Indexed: 11/16/2022]
Abstract
Hepatic encephalopathy (HE) is a neurological complication that affects attention and memory. Experimental animal models have been used to study HE, the most frequent being the portacaval shunt (PCS). In order to investigate learning impairment and brain functional alterations in this model, we assessed reversal learning and neural metabolic activity in a PCS rat model. PCS and sham-operated rats were tested for reversal learning in the Morris water maze. Brains were then processed for cytochrome oxidase (CO) histochemistry. The PCS group had reversal learning impairment and a reduction in CO activity in the prefrontal cortex, ventral tegmental area and accumbens shell nucleus. These results suggest that this model of portosystemic HE shows learning impairments that could be linked to dysfunction in neural activity in the prefrontal cortex and regions involved in motivated behavior.
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Affiliation(s)
- M Méndez
- Laboratorio de Neurociencias, Departamento de Psicología, Universidad de Oviedo, Plaza Feijoo s/n. 33003, Oviedo, Spain.
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Oria M, Chatauret N, Chavarria L, Romero-Giménez J, Palenzuela L, Pardo-Yules B, Arranz JA, Bodega G, Raguer N, Córdoba J. Motor-evoked potentials in awake rats are a valid method of assessing hepatic encephalopathy and of studying its pathogenesis. Hepatology 2010; 52:2077-85. [PMID: 20890898 DOI: 10.1002/hep.23938] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Accepted: 08/17/2010] [Indexed: 12/07/2022]
Abstract
UNLABELLED Experimental models of hepatic encephalopathy (HE) are limited by difficulties in objectively monitoring neuronal function. There are few models that examine a well-defined neuronal pathway and lack the confounding effects of anesthetics. Motor-evoked potentials (MEPs) assess the function of the motor tract, which has been shown to be impaired in patients with cirrhosis. MEPs were elicited by cranial stimulation (central) and compound motor action potential by sciatic nerve stimulation (peripheral) in several models of HE in the rat. The experiments were performed using subcutaneous electrodes without anesthetics. Brain water content was assessed by gravimetry, brain metabolites were measured by magnetic resonance spectroscopy, and amino acids in microdialysates from the frontal cortex were analyzed by high-performance liquid chromatography. Abnormalities of MEP were observed in acute liver failure (ALF) induced by hepatic devascularization in relation to the progression of neurological manifestations. Similar disturbances were seen in rats with portocaval anastomosis after the administration of blood or lipopolysaccharide, but were absent in rats with biliary duct ligation. Hypothermia (≤35°C) and mannitol prevented the development of brain edema in acute liver failure, but only hypothermia avoided the decrease in the amplitude of MEP. Disturbances of MEP caused by the administration of blood into the gastrointestinal tract in rats with portocaval anastomosis were associated with an increase in ammonia, glutamine, and glutamate in brain microdialysate. CONCLUSION Assessment of MEP in awake rats is a valid method to monitor HE in models of ALF and precipitated HE. This method shows the lack of efficacy of mannitol, a therapy that decreases brain edema, and relates disturbances of the function of the motor tract to ammonia and its metabolites.
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Affiliation(s)
- Marc Oria
- Servei de Medicina Interna-Hepatologia, Hospital Vall d'Hebron, Barcelona, Spain
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10
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Erceg S, Ronaghi M, Oria M, Roselló MG, Aragó MAP, Lopez MG, Radojevic I, Moreno-Manzano V, Rodríguez-Jiménez FJ, Bhattacharya SS, Cordoba J, Stojkovic M. Transplanted oligodendrocytes and motoneuron progenitors generated from human embryonic stem cells promote locomotor recovery after spinal cord transection. Stem Cells 2010; 28:1541-9. [PMID: 20665739 PMCID: PMC2996083 DOI: 10.1002/stem.489] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Human embryonic stem cells (hESC) hold great promise for the treatment of patients with many neurodegenerative diseases particularly those arising from cell loss or neural dysfunction including spinal cord injury. This study evaluates the therapeutic effects of transplanted hESC-derived oligodendrocyte progenitors (OPC) and/or motoneuron progenitors (MP) on axonal remyelination and functional recovery of adult rats after complete spinal cord transection. OPC and/or MP were grafted into the site of injury in the acute phase. Based on Basso-Beattie-Bresnahan scores recovery of locomotor function was significantly enhanced in rats treated with OPC and/or MP when compared with control animals. When transplanted into the spinal cord immediately after complete transection, OPC and MP survived, migrated, and differentiated into mature oligodendrocytes and neurons showing in vivo electrophysiological activity. Taken together, these results indicate that OPC and MP derived from hESC could be a useful therapeutic strategy to repair injured spinal cord. Stem Cells 2010; 28:1541–1549.
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Affiliation(s)
- Slaven Erceg
- Cellular Reprogramming Laboratory, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain.
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Miquel M, Bartolí R, Odena G, Serafín A, Cabré E, Galan A, Barba I, Córdoba J, Planas R. Rat CCl(4)-induced cirrhosis plus total portal vein ligation: a new model for the study of hyperammonaemia and brain oedema. Liver Int 2010; 30:979-87. [PMID: 20492509 DOI: 10.1111/j.1478-3231.2010.02273.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
INTRODUCTION Animal models used to study hyperammonaemic disorders related to chronic liver disease are unsatisfactory. These animals only develop hyperammonaemia and brain oedema when fed with diets supplemented with amonium acetate. AIM To develop a novel experimental model of hyperammonaemia and brain oedema in CCl(4)-induced cirrhosis in rats. METHODS Four groups were studied: rats with sham intervention (S), rats with total portal vein ligation (TPVL), cirrhotic rats (LC), and cirrhotic rats with TPVL (LC+TPVL). When ascites was diagnosed, oral glutamine challenge (OGC) test was performed. Blood, liver, lungs and brain samples were collected to quantify liver function parameters, plasmatic and cerebral ammonia, endotoxaemia, liver and brain histology, brain oedema and portosystemic shunting degree. RESULTS LC+TPVL rats showed a significant increase in portosystemic shunting when compared with LC group and a significant derangement in liver function when compared with TPVL group. These alterations resulted in a significant increase in plasmatic and brain ammonia concentrations and a higher plasmatic endotoxaemia as compared with others. Similarly, the area under OGC curve was significantly increased in LC+TPVL group as compared with the others, and correlates with portal shunting. Low-grade brain oedema was only observed in LC+TPVL group. All cirrhotic groups showed liver regeneration nodules and type-II Alzheimer astrocytes CONCLUSION LC+TPVL reproduce the main alterations - portosystemic shunting, plasmatic and cerebral hyperammonaemia and low-grade brain oedema - observed in cirrhotic patients with hepatic encephalopathy.
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Affiliation(s)
- Mireia Miquel
- Germans Trias i Pujol Health Science Research Institute, Badalona, Spain
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Guerit JM, Amantini A, Fischer C, Kaplan PW, Mecarelli O, Schnitzler A, Ubiali E, Amodio P. Neurophysiological investigations of hepatic encephalopathy: ISHEN practice guidelines. Liver Int 2009; 29:789-96. [PMID: 19638107 DOI: 10.1111/j.1478-3231.2009.02030.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
By studying neuronal activity through neuronal electrogenesis, neurophysiological investigations provide a functional assessment of the nervous system and, therefore, has been used for quantitative assessment and follow-up of hepatic encephalopathy (HE). The different clinical neurophysiological approaches can be classified depending on the function to explore and their sensitivity to HE. The reliable techniques are those that reflect cortical function, i.e., cognitive-evoked potentials (EPs) (P300 paradigm), electroencephalogram (EEG), visual EPs (latency>100 ms) and somatosensory EPs (SEPs) (latency between 25 and 100 ms). Short-latency EPs (brainstem acoustic EPs, SEPs of a latency<25 ms) are in principle insensitive to HE, but can disclose brainstem conduction deficits due to oedema. SEPs and motor EPs can disclose myelopathies. Because of its parallelism to the clinical examination, clinical neurophysiology can complement the neurological examination: (i) to provide evidence of HE in patients who have normal consciousness; (ii) to rule out, at least under some conditions, disturbances of consciousness due to other causes (e.g. drug-induced disturbances, non-convulsive status epilepticus) with the reservation that the mildest degrees of encephalopathy might be associated with an EEG pattern similar to that induced by drugs; and (iii) to demonstrate the worsening or, conversely improvement, of HE in the follow-up period.
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Coll M, Genescà J, Raurell I, Rodríguez-Vilarrupla A, Mejías M, Otero T, Oria M, Esteban R, Guardia J, Bosch J, Martell M. Down-regulation of genes related to the adrenergic system may contribute to splanchnic vasodilation in rat portal hypertension. J Hepatol 2008; 49:43-51. [PMID: 18457899 DOI: 10.1016/j.jhep.2008.03.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2007] [Revised: 02/29/2008] [Accepted: 03/25/2008] [Indexed: 01/15/2023]
Abstract
BACKGROUND/AIMS Splanchnic vasodilation initiates the hyperdynamic syndrome in portal hypertension. We aimed to explore molecular mechanisms involved in the development of mesenteric vasodilation in portal hypertension. METHODS Superior mesenteric artery (SMA) samples from portal vein ligated (PVL) and sham rats were compared in a time course experiment using DNA microarrays. Selected genes were quantified by qRT-PCR in PVL and cirrhotic rats. Inmunohistochemistry of tyrosine hydroxylase (Th) and norepinephrine was assessed in SMA sections of PVL and sham rats. Western blot analysis of Th, dopamine beta-hydroxylase (Dbh) and synaptosome-associated protein (Snap-25) was performed in SMA and jejunum samples from the animal models. RESULTS Fifty differentially expressed genes implicated in neurotransmission, especially adrenergic, were detected in SMA samples from PVL rats. Sequential analysis showed a profound down-regulation at 14 days in PVL rats. These down-regulated genes were confirmed by RT-PCR in SMA from PVL and cirrhotic rats. Th and NE detection by immunohistochemistry was reduced in PVL compared to sham. Th, Dbh and Snap-25 expression was lower in SMA from 14-day PVL and cirrhotic rats compared to sham and control rats, respectively. CONCLUSIONS Genetic down-regulation of genes related to the adrenergic system might have a role in splanchnic vasodilation of portal hypertension.
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Affiliation(s)
- Mar Coll
- Liver Diseases Laboratory, Liver Unit, Department of Internal Medicine, Hospital Universitari Vall d'Hebron, Institut de Recerca Vall d'Hebron, Universitat Autònoma de Barcelona, Pg. Vall d'Hebron 119-127, 08035 Barcelona, Spain
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Oria M, Chatauret N, Raguer N, Córdoba J. A new method for measuring motor evoked potentials in the awake rat: effects of anesthetics. J Neurotrauma 2008; 25:266-75. [PMID: 18352840 DOI: 10.1089/neu.2007.0393] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The goal of this investigation was to develop a method to study the neurophysiological integrity of the central motor tract using motor evoked potentials in the awake rat and assess the effects of different anesthetics in this model. Rats were implanted with six subcutaneous electrodes (pediatric myocardial pacing leads) and one cranial screw. Motor evoked potentials of the hind limb were elicited after cranial and sciatic nerve stimulation. Experiments were repeated on different days during three weeks studying the effect of three different anesthetics (propofol, ketamine/xylazine, pentobarbital) at three different doses. Stimulation of motor evoked potentials in the awake rat was well tolerated with no effects on behavior. The electrodes could be kept chronically in place without signs of infection. The repeated recordings on different days showed high reproducibility after the fourth day following implantation of the electrodes. All three anesthetics induced an increase in the latency and a decrease in the amplitude of the motor evoked potentials which were dose dependent. Propofol (up to 1 mg/kg x min(1)) affected motor evoked potentials to a lesser extent than the other anesthetics. Based upon these findings, we believe that our approach provides a new method of chronically implanting electrodes in the rat to assess the neurophysiological function of the motor tract without the need of anesthetics. This model may prove useful in the investigation of various diseases that affect the motor pathways without the confounding effects of anesthesia.
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Affiliation(s)
- Marc Oria
- Servicio de Medicina Interna-Hepatología, Hospital Vall d'Hebron, Barcelona, Spain
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Méndez M, Méndez-López M, López L, Aller MA, Arias J, Cimadevilla JM, Arias JL. Spatial memory alterations in three models of hepatic encephalopathy. Behav Brain Res 2007; 188:32-40. [PMID: 18063138 DOI: 10.1016/j.bbr.2007.10.019] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2007] [Revised: 10/18/2007] [Accepted: 10/21/2007] [Indexed: 01/01/2023]
Abstract
A behavioural evaluation was carried out on three chronic models of hepatic encephalopathy: two models of type B HE, portacaval shunt (PCS) and portal hypertension (PH) and one of type C HE with cirrhosis and portal hypertension from thioacetamide intoxication (TAA). The tasks selected cover a wide range of behaviours related to: locomotion (rotarod-accelerod test), anxiety (open field and elevated plus maze) and memory (Morris water maze). The results indicate that neither locomotor activity nor anxiety was affected in our models, in comparison with their respective controls. However, this is not the case for the mnesic tasks. Hence, the PCS and TAA groups displayed a severe alteration in spatial reference memory and cannot correctly perform the Morris maze task, while this alteration is less severe in the PH group. On the contrary, the PH group revealed a deficit in spatial working memory, like the TAA group, but this does not occur in subjects with PCS. These results reveal a double dissociation in spatial reference memory and spatial working memory between the PCS and PH groups, which would be of great interest to study about cerebral causes and substrates of the alterations accompanying HE.
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Affiliation(s)
- Marta Méndez
- Laboratorio de Neurociencias, Departamento de Psicología, Universidad de Oviedo, Plaza Feijoo s/n, 33003 Oviedo, Spain
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