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1.
Rev Gastroenterol Mex (Engl Ed) ; 88(1): 57-70, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36737343

RESUMEN

Complementary feeding (CF) is defined as the feeding of infants that complements breastfeeding, or alternatively, feeding with a breast milk substitute, and is a process that is more than simply a guide as to what and how to introduce foods. The information provided by healthcare professionals must be up-to-date and evidence-based. Most of the recommendations that appear in the different international guidelines and position papers are widely applicable, but some must be regionalized or adapted to fit the conditions and reality of each geographic zone. The Nutrition Working Group of the Latin American Society for Pediatric Gastroenterology, Hepatology and Nutrition (LASPGHAN) summoned a group of experts from each of the society's member countries, to develop a consensus on CF, incorporating, whenever possible, local information adapted to the reality of the region. The aim of the present document is to show the results of that endeavor. Utilizing the Delphi method, a total of 34 statements on relevant aspects of CF were evaluated, discussed, and voted upon.


Asunto(s)
Gastroenterología , Lactante , Niño , Femenino , Humanos , Cocos , Consenso , América Latina , Fenómenos Fisiológicos Nutricionales del Lactante
2.
Neurologia (Engl Ed) ; 34(5): 318-325, 2019 Jun.
Artículo en Inglés, Español | MEDLINE | ID: mdl-27939111

RESUMEN

INTRODUCTION: Much has been published on syringomyelia related to Chiari malformation. In contrast, little is known about the condition when it is not associated with this malformation, but this presentation of syringomyelia constitutes a different entity and therefore requires specific management. We conducted a literature review to summarise the most accepted and widespread ideas about the pathophysiology, management and other aspects of syringomyelia unrelated to Chiari malformation. DEVELOPMENT: We reviewed the most relevant literature on this condition, focusing on the pathophysiology, clinical presentation, diagnosis, and treatment. CONCLUSIONS: Syringomyelia unrelated to Chiari malformation is a distinct entity that must be well understood to guarantee correct diagnosis, monitoring, and management. When the disease is suspected, a thorough study should be conducted to identify its aetiology. Treatment must aim to eliminate the cause of the disease; symptomatic treatment should remain a second-line option.


Asunto(s)
Siringomielia/fisiopatología , Siringomielia/terapia , Malformación de Arnold-Chiari/complicaciones , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Complicaciones Posoperatorias/diagnóstico , Siringomielia/diagnóstico , Siringomielia/etiología , Resultado del Tratamiento
3.
J Antimicrob Chemother ; 69(6): 1669-74, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24532682

RESUMEN

OBJECTIVES: Enterococcus spp. account for 10% of infective endocarditis (IE). Although daptomycin is a bactericidal drug with in vitro activity against Enterococcus, there is little experience of its use in IE. We analysed the effectiveness of daptomycin in the treatment of enterococcal IE (EIE). METHODS: This was a retrospective descriptive study comparing the efficacy of daptomycin versus ampicillin/ceftriaxone versus conventional antibiotic regimens (ampicillin or vancomycin ±â€Šgentamicin) in EIE. RESULTS: From January 2007 to December 2011, 6 patients with EIE treated with daptomycin monotherapy were compared with 21 patients treated with ampicillin/ceftriaxone and 5 patients treated with ampicillin or vancomycin ±â€Šgentamicin. The three groups had similar epidemiological and clinical characteristics. Daptomycin indications were allergy to ß-lactams (n = 3), therapy simplification (n = 2), renal failure (n = 2) and Enterococcus faecium resistant to ampicillin/gentamicin (n = 1). Daptomycin MICs ranged from 1 to 2 mg/L and the doses were 6-10 mg/kg/day intravenously. Daptomycin patients had longer duration of bacteraemia (6 versus 1 day, P < 0.01) and greater need of therapy switch due to complications (66.7% versus 0%, P < 0.01). There were no differences regarding duration of hospital stay or mortality. CONCLUSIONS: Daptomycin-treated patients more frequently required a therapeutic change due to worse microbiological and clinical response, although mortality was not increased. Our findings do not support the use of daptomycin as single therapy in the treatment of EIE. Its role in combined strategies should be further investigated.


Asunto(s)
Antibacterianos/uso terapéutico , Daptomicina/uso terapéutico , Endocarditis Bacteriana/tratamiento farmacológico , Enterococcus , Infecciones por Bacterias Grampositivas/complicaciones , Anciano , Anciano de 80 o más Años , Comorbilidad , Infección Hospitalaria/tratamiento farmacológico , Infección Hospitalaria/microbiología , Sustitución de Medicamentos , Quimioterapia Combinada , Femenino , Humanos , Masculino , Estudios Retrospectivos , Factores de Riesgo , Resultado del Tratamiento
4.
Neuroscience ; 265: 313-22, 2014 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-24486437

RESUMEN

High molecular weight (HMW) glycosaminoglycanes of the extracellular matrix have been implicated in tissue repair. The aim of this study was to evaluate if small synthetic hyaluronan disaccharides with different degrees of sulfation (methyl 2-acetamido-2-deoxy-3-O-(ß-d-glucopyranosyluronic acid)-O-sulfo-α-d-glucopyranoside, sodium salt (di0S), methyl 2-acetamido-2-deoxy-3-O-(ß-d-glucopyranosyluronic acid)-6-di-O-sulfo-α-d-glucopyranoside, disodium salt (di6S) and methyl 2-acetamido-2-deoxy-3-O-(ß-d-glucopyranosyluronic acid)-4,6-di-O-sulfo-α-d-glucopyranoside, trisodium salt (di4,6S)) could improve cell survival in in vitro and in vivo brain ischemia-related models. Rat hippocampal slices subjected to oxygen and glucose deprivation and a photothrombotic stroke model in mice were used. The three hyaluran disaccharides, incubated during the oxygen and glucose deprivation (15min) and re-oxygenation periods (120min), reduced cell death of hippocampal slices measured as 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction, being the most potent di4,6S; in contrast, high molecular hyaluronan was ineffective. The protective actions of di4,6S against oxygen and glucose deprivation were related to activation of the PI3K/Akt survival pathway, reduction of p65 translocation to the nucleus, inhibition of inducible nitric oxide oxidase induction and reactive oxygen species production, and to an increase in glutathione levels. Administered 1h post-stroke, di4,6S reduced cerebral infarct size and improved motor activity in the beam walk test. In conclusion, di4,6S affords neuroprotection in in vitro and in vivo models of ischemic neuronal damage. Our results suggest that its neuroprotective effect could be exerted through its capability to reduce oxidative stress during ischemia. Its small molecular size makes it a more potential druggable drug to target the brain as compared with its HMW parent compound hyaluronan.


Asunto(s)
Isquemia Encefálica/tratamiento farmacológico , Disacáridos/uso terapéutico , Hipocampo/efectos de los fármacos , Ácido Hialurónico/uso terapéutico , Fármacos Neuroprotectores/uso terapéutico , Estrés Oxidativo/efectos de los fármacos , Animales , Isquemia Encefálica/metabolismo , Supervivencia Celular/efectos de los fármacos , Disacáridos/química , Modelos Animales de Enfermedad , Hipocampo/metabolismo , Ácido Hialurónico/química , Masculino , Ratones , Ratas , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismo
5.
Neurologia ; 29(6): 353-70, 2014.
Artículo en Inglés, Español | MEDLINE | ID: mdl-23044408

RESUMEN

OBJECTIVE: To update the Spanish Society of Neurology's guidelines for subarachnoid haemorrhage diagnosis and treatment. MATERIAL AND METHODS: A review and analysis of the existing literature. Recommendations are given based on the level of evidence for each study reviewed. RESULTS: The most common cause of spontaneous subarachnoid haemorrhage (SAH) is cerebral aneurysm rupture. Its estimated incidence in Spain is 9/100 000 inhabitants/year with a relative frequency of approximately 5% of all strokes. Hypertension and smoking are the main risk factors. Stroke patients require treatment in a specialised centre. Admission to a stroke unit should be considered for SAH patients whose initial clinical condition is good (Grades I or II on the Hunt and Hess scale). We recommend early exclusion of aneurysms from the circulation. The diagnostic study of choice for SAH is brain CT (computed tomography) without contrast. If the test is negative and SAH is still suspected, a lumbar puncture should then be performed. The diagnostic tests recommended in order to determine the source of the haemorrhage are MRI (magnetic resonance imaging) and angiography. Doppler ultrasonography studies are very useful for diagnosing and monitoring vasospasm. Nimodipine is recommended for preventing delayed cerebral ischaemia. Blood pressure treatment and neurovascular intervention may be considered in treating refractory vasospasm. CONCLUSIONS: SAH is a severe and complex disease which must be managed in specialised centres by professionals with ample experience in relevant diagnostic and therapeutic processes.


Asunto(s)
Guías de Práctica Clínica como Asunto , Hemorragia Subaracnoidea/diagnóstico , Hemorragia Subaracnoidea/terapia , Isquemia Encefálica/complicaciones , Angiografía Cerebral , Humanos , Aneurisma Intracraneal/complicaciones , Imagen por Resonancia Magnética , Nimodipina/uso terapéutico , Factores de Riesgo , Punción Espinal , Hemorragia Subaracnoidea/etiología , Tomografía Computarizada por Rayos X/métodos
6.
B-ENT ; 8(3): 167-71, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23113378

RESUMEN

OBJECTIVE: This study on patients undergoing surgery for vestibular schwannoma investigated tumour (i) the effect of pre-operative factors on tinnitus, (ii) the effect of translabyrinthine or hearing preservation surgical approaches on tinnitus, and (iii) the effect of postoperative tinnitus status on the patient's quality of life (QOL). METHODOLOGY: Seventy-nine patients who underwent vestibular schwannoma (VS) excision between 2001 and 2005 were selected. Postoperative tinnitus status was evaluated using a standard questionnaire for tinnitus, and QOL was measured using the Glasgow Benefit Inventory (GBI). RESULTS: Overall, 58% of patients noted tinnitus before tumour removal. Pre-operative tinnitus was not associated with age, gender, tumour size, or hearing thresholds. The total percentage of patients suffering postoperative tinnitus was 64%. Hearing preservation approaches showed no difference in terms of changes in tinnitus compared to the translabyrinthine approach. Twenty-one patients (30%) reported better QOL, 40 patients (56%) reported worse QOL, and 10 patients (14%) reported the same QOL. A significant association was found between tinnitus worsening as measured by GBI score and QOL. CONCLUSIONS: Most patients do not report significant changes in their tinnitus status after surgery. Tinnitus evolution is unpredictable and not related to the type of surgical approach. Thus, tinnitus should not be used as a criterion for selecting the surgical approach. Tinnitus worsening appears to influence QOL following surgery for VS.


Asunto(s)
Neuroma Acústico/cirugía , Procedimientos Quirúrgicos Otológicos/efectos adversos , Calidad de Vida , Acúfeno/etiología , Adulto , Anciano , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias , Pronóstico , Estudios Retrospectivos , Encuestas y Cuestionarios , Acúfeno/psicología , Adulto Joven
7.
Clin Microbiol Infect ; 18(3): 293-9, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21733030

RESUMEN

The duration of antimicrobial therapy after surgery for infective endocarditis (IE) is controversial. A short course of postsurgical therapy is currently accepted only for patients with negative valve culture. We performed a retrospective (1994-2008) analysis of patients who underwent surgery for IE in our hospital and had a high risk of complications ( one of more of the following: <2 weeks of antibiotic treatment before surgery; embolism; perivalvular extension; and positive valve culture) to compare outcomes of patients who received short-course antimicrobial therapy (SAT) (median 15 days) or long-course antimicrobial therapy (LAT) (median 32 days), irrespective of the results of valve culture. Our endpoints included length of hospital stay, renal and hepatic failure, relapse, re-infection, and mortality rates 1 year after surgery. During the study period, 140 patients underwent surgery for IE (valve replacement, 87.9%). Of these, 133 fulfilled the high-risk group criteria and 92 completed the antimicrobial schedule. Comparison of patients receiving SAT (37) and LAT (55) showed that the SAT group had a shorter length of hospital stay (29 vs. 40 days, p 0.01), and a trend towards lower frequency of renal failure (5.4% vs. 18.2%, p 0.11) and hepatic failure (5.4% vs. 9.1%, p 0.69), whereas mortality (5.4% vs. 3.6%, p 1), relapse (0% vs. 1.8%, p 1) and re-infection (5.4% vs. 3.6%, p 1) rates were similar between both groups. Multivariate analysis showed that IE caused by Streptococcus viridans or Streptococcus bovis was independently associated with SAT. Postsurgical SAT is safe, especially when IE is caused by Streptococcus viridans or Streptococcus bovis, even in patients at high risk of complications.


Asunto(s)
Antibacterianos/administración & dosificación , Endocarditis Bacteriana/tratamiento farmacológico , Cuidados Posoperatorios/métodos , Infecciones Estreptocócicas/tratamiento farmacológico , Streptococcus bovis/patogenicidad , Estreptococos Viridans/patogenicidad , Adulto , Anciano , Endocarditis Bacteriana/microbiología , Endocarditis Bacteriana/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/epidemiología , Estudios Retrospectivos , Infecciones Estreptocócicas/microbiología , Infecciones Estreptocócicas/cirugía , Factores de Tiempo , Resultado del Tratamiento
8.
Endocrinology ; 152(7): 2816-26, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21558318

RESUMEN

Fetal growth restriction followed by accelerated postnatal growth contributes to impaired metabolic function in adulthood. The extent to which these outcomes may be mediated centrally within the hypothalamus, as opposed to in the periphery within the digestive tract, remains unknown. In a sheep model, we achieved intrauterine growth restriction experimentally by maternal nutrient restriction (R) that involved a 40% reduction in food intake through late gestation. R offspring were then either reared singly to accelerate postnatal growth (RA) or as twins and compared with controls also reared singly. From weaning, all offspring were maintained indoors until adulthood. A reduced litter size accelerated postnatal growth for only the first month of lactation. Independently from postnatal weight gain and later fat mass, R animals developed insulin resistance as adults. However, restricted accelerated offspring compared with both the control accelerated and restricted restricted offspring ate less and had higher fasting plasma leptin as adults, an adaptation which was accompanied by changes in energy sensing and cell proliferation within the abomasum. Additionally, although fetal restriction down-regulated gene expression of mammalian target of rapamycin and carnitine palmitoyltransferase 1-dependent pathways in the abomasum, RA offspring compensated for this by exhibiting greater activity of AMP-activated kinase-dependent pathways. This study demonstrates a role for perinatal nutrition in the peripheral control of food intake and in energy sensing in the gastric mucosal and emphasizes the importance of diet in early life in regulating energy metabolism during adulthood.


Asunto(s)
Restricción Calórica/efectos adversos , Metabolismo Energético , Retardo del Crecimiento Fetal/etiología , Mucosa Gástrica/metabolismo , Lactancia , Fenómenos Fisiologicos Nutricionales Maternos , Proteínas Quinasas Activadas por AMP/genética , Proteínas Quinasas Activadas por AMP/metabolismo , Abomaso/crecimiento & desarrollo , Abomaso/metabolismo , Abomaso/patología , Adiposidad , Animales , Carnitina O-Palmitoiltransferasa/genética , Carnitina O-Palmitoiltransferasa/metabolismo , Proliferación Celular , Femenino , Retardo del Crecimiento Fetal/metabolismo , Retardo del Crecimiento Fetal/patología , Retardo del Crecimiento Fetal/fisiopatología , Mucosa Gástrica/crecimiento & desarrollo , Mucosa Gástrica/patología , Regulación de la Expresión Génica , Resistencia a la Insulina , Leptina/sangre , Leptina/genética , Leptina/metabolismo , Masculino , Embarazo , ARN Mensajero/metabolismo , Distribución Aleatoria , Ovinos , Serina-Treonina Quinasas TOR/genética , Serina-Treonina Quinasas TOR/metabolismo , Aumento de Peso
9.
Neuroscience ; 175: 394-405, 2011 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-21144885

RESUMEN

Hematic administration of bone marrow-derived mesenchymal stem cells (MSCs) in acute ischemic stroke may not only be an effective reparative treatment but also a brain protective therapy that improves neurological recovery. Our purpose was to study whether either i.v. or intracarotid (i.c.) administration of allogenic MSCs during the acute phase were effective in improving neurological recovery and decreasing brain damage in an experimental rat model. In a model of permanent middle cerebral artery occlusion (pMCAO), we analyzed: neurological evaluation; MSCs migration and implantation; interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) levels; lesion volume; cell death; cellular proliferation; vascular endothelial growth factor (VEGF) expression and blood vessel number. Regardless of the administration route, treated groups showed better neurological recovery, without significant differences between the two groups. Migration and implantation of MSCs in the lesion area was observed in animals receiving i.c. but not i.v. treatment. The highest cytokine values were observed in the i.v. MSCs and i.c. control groups, and these levels were significantly different from the corresponding i.v. control and i.c. MSCs groups, respectively. In addition, there were significant differences between the i.v. MSCs and i.c. MSCs groups in IL-6 levels. Neither treatment reduced infarction volume. However, cell death, measured as TUNEL+ cells was decreased with significant differences between control groups. BrdU+ cells were also significantly increased in the peri-infarct zone at 14 days. VEGF expression was significantly higher in the i.c. MSCs group than in the i.c. control group and blood vessel number was significantly higher in treated groups than control groups with significant differences in the peri-infarct zone at 14 days. We conclude that allogenic MSCs administration shows therapeutic efficacy in our acute ischemic stroke model. Both routes demonstrably improved neurological recovery and provided brain protection.


Asunto(s)
Isquemia Encefálica/terapia , Trasplante de Células Madre Mesenquimatosas/métodos , Recuperación de la Función/fisiología , Accidente Cerebrovascular/terapia , Animales , Isquemia Encefálica/patología , Isquemia Encefálica/fisiopatología , Arteria Carótida Interna , Células Cultivadas , Modelos Animales de Enfermedad , Femenino , Inyecciones Intraarteriales , Inyecciones Intravenosas , Inyecciones Intraventriculares , Masculino , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Accidente Cerebrovascular/patología , Accidente Cerebrovascular/fisiopatología , Trasplante Homólogo/métodos
10.
Neurologia ; 26(2): 65-73, 2011 Mar.
Artículo en Inglés, Español | MEDLINE | ID: mdl-21163184

RESUMEN

The major aim of experimental models of cerebral ischemia is to study the cerebral ischemic damage under controlled and reproducible conditions. Experimental studies have been fundamental in the establishment of new concepts regarding the mechanisms underlying the ischemic brain injury, such as the ischemic penumbra, the reperfusion injury, the cell death or the importance of the damage induced on mitochondria, glial cells and white matter. Disagreement between experimental and clinical studies regarding the benefit of drugs to reduce or restore the cerebral ischemic damage has created a growing controversy about the clinical value of the experimental models of cerebral ischemia. One of the major explanations for the failure of the clinical trials is the reductionist approach of most therapies, which are focused on the known effect of a single molecule within a specific pathway of ischemic damage. This philosophy contrasts to the complex morphological design of the cerebral tissue and the complex cellular and molecular physiopathology underlying the ischemic brain injury. We believe that the main objective of studies carried out in experimental models of cerebral ischemic injury must be a better understanding of the fundamental mechanisms underlying progression of the ischemic injury. Clinical trials should not be considered if the benefit obtained in experimental studies is limited or weak.


Asunto(s)
Investigación Biomédica , Isquemia Encefálica/terapia , Modelos Animales de Enfermedad , Animales , Humanos , Reproducibilidad de los Resultados
11.
Histol Histopathol ; 24(12): 1487-98, 2009 12.
Artículo en Inglés | MEDLINE | ID: mdl-19795347

RESUMEN

The purpose of this study was to assess the effects of the addition of Nitroglycerin or Nicorandil to University of Wisconsin solution in long-term myocardial preservation. In a model of heterotopic heart transplantation in pigs, the donor heart was preserved for 24 hours by means of continuous perfusion in this solution, in the presence or absence of these drugs. During this period, the oxygenation and pH of the solution were measured, as were lactate concentrations and enzyme release. At regular intervals following reperfusion we measured the concentrations of enzymes, antioxidants, glutathione peroxidase, glutathione reductase, malondialdehyde, endothelin and nitrite, and, two hours later, samples of both ventricles were taken for a morphological study. In the treated groups there was a higher lactate production during preservation and, during reperfusion, the signs of contracture and the elevation of enzyme levels were more marked than in the untreated groups. In contrast, the glutathione reductase concentrations did not decrease during the first phase of reperfusion and were directly correlated with those of antioxidants, endothelin levels increased less than in the untreated groups and, in the case of nitroglycerin, the nitrite concentration was significantly greater than in the remaining groups. We conclude that nitroglycerin and nicorandil improved the oxidative state and endothelial function and did not produce substantial morphological changes, but increased cell necrosis and contracture, possibly due to the duration of ischemia.


Asunto(s)
Endotelio/efectos de los fármacos , Nicorandil/farmacología , Nitroglicerina/farmacología , Preservación de Órganos/métodos , Vasodilatadores/farmacología , Adenosina , Alopurinol , Animales , Antioxidantes/metabolismo , Calcio/análisis , Dióxido de Carbono/análisis , Creatina Quinasa/análisis , Endotelina-1/efectos de los fármacos , Endotelio/fisiología , Técnica del Anticuerpo Fluorescente Indirecta , Glucosa/análisis , Glutatión , Glutatión Peroxidasa/metabolismo , Glutatión Reductasa/metabolismo , Trasplante de Corazón/métodos , Ventrículos Cardíacos/efectos de los fármacos , Ventrículos Cardíacos/patología , Ventrículos Cardíacos/ultraestructura , Concentración de Iones de Hidrógeno , Inmunohistoquímica , Insulina , L-Lactato Deshidrogenasa/análisis , Ácido Láctico/análisis , Malondialdehído/análisis , Miocardio/metabolismo , Miocardio/ultraestructura , Nitritos/análisis , Soluciones Preservantes de Órganos , Oxígeno/análisis , Soluciones Farmacéuticas/farmacología , Rafinosa , Distribución Aleatoria , Porcinos , Factores de Tiempo
12.
Neurocirugia (Astur) ; 20(3): 225-44, 2009 Jun.
Artículo en Español | MEDLINE | ID: mdl-19575127

RESUMEN

AIM: To provide a summary of the different experimental models of traumatic brain injury (TBI) designed under both in vivo and in vitro conditions. A comprehensible review of the specific types of brain lesions induced, as well as the technical details to reproduce each model at the laboratory is given. DEVELOPMENT: Outcome of patients suffering from a TBI has significantly improved with the rapid application of vital supporting measures in addition to a strict control of blood and intracranial pressure at the intensive care units. However no specific treatment for post-traumatic brain lesions has proven as efficacious in the clinical settings. A deeper knowledge of the physiopathological events associated with TBI is necessary for the development of new specific therapies. Due to the heterogeneity of the human TBI, each experimental model has been designed to reproduce a different type of brain lesion. Experimental TBI models allow the study of the dynamic evolution of brain injuries under controlled conditions. Usefulness of experimental models is limited by their reliability and reproducibility among different researchers. Small rodents have been the preferred animals to reproduce TBI injuries, mainly due to the similar cerebral physiology shared by these animals and the human beings. CONCLUSION: The use of experimental models of TBI is the most appropriate tool to study the mechanisms underlying this type of injury. However their simplicity precludes an exact reproduction of the heterogeneous cerebral damage observed in clinical settings. This could be the main reason for the discrepancies observed in the therapeutic effects of treatments between experimental and clinical studies.


Asunto(s)
Lesiones Encefálicas , Modelos Animales , Animales , Lesiones Encefálicas/patología , Lesiones Encefálicas/terapia , Humanos , Reproducibilidad de los Resultados , Resultado del Tratamiento
13.
Rev Neurol ; 47(8): 414-26, 2008.
Artículo en Español | MEDLINE | ID: mdl-18937203

RESUMEN

AIM: To provide a summary of the different experimental models of cerebral ischemia designed both under in vivo and in vitro conditions. A clear and concise description of the specific types of brain lesion reproduced by each model is given together with the most frequent technical troubles associated. DEVELOPMENT: Experimental models of cerebral ischemia have contributed substantially to the understanding of the physiopathology of the ischemic brain injury and to test the beneficial effects of new therapies. Outcome of patients suffering from an ischemic stroke has improved considerably with the use of these models, particularly after the introduction of thrombolytic and neuroprotective drugs. Experimental models allow the study of the evolving ischemic brain injury under strict and controlled conditions. Usefulness of experimental models is limited by their reliability, simplicity and reproducibility among different researchers. Small rodents, especially rats, have been the preferred animals used to develop models of cerebral ischemic injury, due to their cerebral physiology and vascularisation which is closer to the human. CONCLUSION: The use of experimental models of cerebral ischemia constitutes the most suitable tool to investigate the physiopathology of this type of injury. However their simplicity prevents an exact reproduction of the cerebral damage observed in clinical settings. This could be the main reason for the discrepancies observed between the therapeutic effect in the experimental and clinical studies.


Asunto(s)
Isquemia Encefálica/patología , Isquemia Encefálica/fisiopatología , Modelos Animales de Enfermedad , Animales , Isquemia Encefálica/terapia , Circulación Cerebrovascular , Humanos , Infarto de la Arteria Cerebral Media/patología , Infarto de la Arteria Cerebral Media/fisiopatología , Fármacos Neuroprotectores/uso terapéutico , Flujo Sanguíneo Regional , Terapia Trombolítica
14.
Mol Psychiatry ; 13(1): 99-114, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17486105

RESUMEN

The N-methyl-D-aspartate receptor (NMDAR) is central to physiological and pathological functioning of neurons. Although promising results are beginning to be obtained in the treatment of dementias, clinical trials with NMDAR antagonists for stroke, trauma and neurodegenerative disorders, such as Hungtinton's disease, have failed before. In order to design effective therapies to prevent excitotoxic neuronal death, it is critical to characterize the consequences of excessive NMDAR activation on its expression and function. Previous data have reported partial downregulation of the NR1 and NR2B receptor subunits in response to excitotoxicity and cerebral ischemia. However, the effect of NMDAR overactivation on NR2A, a subunit fundamental to synaptic transmission and neuronal survival, is still elusive. In this study, we report the rapid and extensive proteolytic processing of NR2A, together with the scaffolding protein postsynaptic density-95 (PSD-95), induced by excitotoxic stimulation of cortical neurons in vitro and by transient focal cerebral ischemia. Processing of the C terminus of NR2A is irreversibly induced by brief agonist exposure of NR2B-containing receptors, and requires calcium influx and the activity of calpain, also responsible for PSD-95 cleavage. The outcome is a truncated NR2A subunit that is stable and capable to interact with NR1 at the surface of neurons, but lacking the structural domains required for association with scaffolding, downstream signaling and cytoskeletal proteins. Therefore, a rapid and significant uncoupling of synaptic NMDARs from downstream survival pathways is expected to occur during ischemia. This novel mechanism induced by excitotoxicity helps to explain the failure of most therapies based on NMDAR antagonists.


Asunto(s)
Isquemia Encefálica/metabolismo , Regulación de la Expresión Génica/fisiología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas de la Membrana/metabolismo , Neuronas/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Animales , Lesiones Encefálicas/metabolismo , Células Cultivadas , Modelos Animales de Enfermedad , Homólogo 4 de la Proteína Discs Large , Péptidos y Proteínas de Señalización Intracelular/efectos de los fármacos , Masculino , Proteínas de la Membrana/efectos de los fármacos , Neuronas/efectos de los fármacos , Neuronas/patología , Neurotoxinas/farmacología , Ratas , Ratas Sprague-Dawley , Ratas Wistar , Receptores de N-Metil-D-Aspartato/efectos de los fármacos
15.
Cerebrovasc Dis ; 21 Suppl 2: 118-26, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16651822

RESUMEN

Stroke is a major cause of death and disability worldwide. The resulting burden on society grows with the increase in the incidence of stroke. The term brain attack was introduced to describe the acute presentation of stroke and emphasize the need for urgent action to remedy the situation. Though a large number of therapeutic agents, like thrombolytics, NMDA receptor antagonists, calcium channel blockers and antioxidants, have been used or are being evaluated, there is still a large gap between the benefits of these agents and the properties of an ideal drug for stroke. So far, only thrombolysis with rtPA within a 3-hour time window has been shown to improve the outcome of patients with ischemic stroke. Understanding the mechanisms of injury and neuroprotection in these diseases is important to target news sites for treating ischemia. Better evaluation of the drugs and increased similarity between the results of animal experimentation and in the clinical setting requires critical assessment of the selection of animal models and the parameters to be evaluated. Our laboratory has employed a rat embolic stroke model to investigate the combination of rtPA with citicoline as compared to monotherapy alone and investigated whether neuroprotection should be provided before or after thrombolysis in order to achieve a greater reduction of ischemic brain damage.


Asunto(s)
Isquemia Encefálica/tratamiento farmacológico , Fibrinolíticos/uso terapéutico , Fármacos Neuroprotectores/uso terapéutico , Accidente Cerebrovascular/tratamiento farmacológico , Terapia Trombolítica , Activador de Tejido Plasminógeno/uso terapéutico , Animales , Encéfalo/efectos de los fármacos , Encéfalo/patología , Isquemia Encefálica/patología , Ensayos Clínicos como Asunto , Citidina Difosfato Colina/farmacología , Citidina Difosfato Colina/uso terapéutico , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos , Quimioterapia Combinada , Fibrinolíticos/farmacología , Humanos , Fármacos Neuroprotectores/farmacología , Ratas , Proteínas Recombinantes/farmacología , Proteínas Recombinantes/uso terapéutico , Accidente Cerebrovascular/patología , Factores de Tiempo , Activador de Tejido Plasminógeno/genética , Activador de Tejido Plasminógeno/farmacología
16.
Clin Neurol Neurosurg ; 108(2): 199-204, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16412844

RESUMEN

UNLABELLED: A glioblastoma presenting as a solitary third ventricle mass is exceptional. CASE DESCRIPTION: We report the case of a 29-year-old woman who lost consciousness, was taken to hospital and referred a previous history of depression and diabetes insipidus. Magnetic resonance imaging study revealed a heterogeneous anterior third ventricle mass with ring enhancement after contrast administration. It was approached and subtotally resected by a transcortical-transventricular route and histological diagnosis proved it to be a glioblastoma. There are only two other similar well-described cases and another nine have been previously reported in surgical series of high grade gliomas and glioblastomas. The possible origin of this lesion is discussed.


Asunto(s)
Neoplasias del Ventrículo Cerebral/diagnóstico , Neoplasias del Ventrículo Cerebral/cirugía , Glioblastoma/diagnóstico , Glioblastoma/cirugía , Tercer Ventrículo , Adulto , Neoplasias del Ventrículo Cerebral/etiología , Femenino , Glioblastoma/etiología , Humanos
17.
Neurocirugia (Astur) ; 16(1): 58-62, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15756413

RESUMEN

We report a unique case of hemangioblastoma of the lateral ventricle in a 73 year-old man with cognitive deficits and fluent dysphasia. He harboured an intraventricular tumor, placed at the trigone of the left lateral ventricle. The tumor was successfully excised, by means of a temporal craniotomy. The patient became mute in the immediate postoperative with restoration of speech within a few days. The literature has been reviewed and only three other similar cases have been reported. Discovery of lesions in such unusual location should raise a high degree of suspicion for von Hippel-Lindau disease.


Asunto(s)
Neoplasias Encefálicas/patología , Ventrículos Cerebrales/patología , Hemangioblastoma/patología , Anciano , Afasia de Wernicke/etiología , Neoplasias Encefálicas/complicaciones , Neoplasias Encefálicas/cirugía , Ventrículos Cerebrales/cirugía , Trastornos del Conocimiento/etiología , Craneotomía , Hemangioblastoma/complicaciones , Hemangioblastoma/cirugía , Humanos , Imagen por Resonancia Magnética , Masculino , Estadificación de Neoplasias , Procedimientos Neuroquirúrgicos
18.
Neurocir. - Soc. Luso-Esp. Neurocir ; 16(1): 58-62, feb. 2005. ilus
Artículo en En | IBECS | ID: ibc-038299

RESUMEN

En este trabajo describimos el caso de un paciente de 73 años con déficits cognitivos y disfasia sensitiva y que fue diagnosticado mediante tomografía computarizada y resonancia magnética cerebral de una lesión tumoral situada en la encrucijada ventricular izquierda. La lesión se abordó quirúrgicamente a través de una craneotomía temporal, realizándose una extirpación total. El estudio anatomopatológico confirmó el diagnóstico de un hemangioblastoma. Durante la evolución postquirúrgica el paciente presentó un cuadro de mutismo transitorio. Una revisión exhaustiva de la literatura ha evidenciado la existencia de tan sólo tres casos similares descritos previamente. El diagnóstico de este tipo de lesiones en una localización tan infrecuente debería hacernos sospechar la enfermedad de von Hippel-Lindau


We report a unique case of hemangioblastoma of the lateral ventricle in a 73 year-old man with cognitive deficits and fluent dysphasia. He harboured an intraventricular tumor, placed at the trigone of the left lateral ventricle. The tumor was successfully excised, by means of a temporal craniotomy. The patient became mute in the immediate postoperative with restoration of speech within a few days. The literature has been reviewed and only three other similar cases have been reported. Discovery of lesions in such unusual location should raise a high degree of suspicion for von Hippel- Lindau disease


Asunto(s)
Masculino , Humanos , Ventrículos Cerebrales/patología , Hemangioblastoma/patología , Neoplasias Encefálicas/patología , Afasia de Wernicke/etiología , Ventrículos Cerebrales/cirugía , Trastornos del Conocimiento/etiología , Craneotomía , Hemangioblastoma/complicaciones , Hemangioblastoma/cirugía , Imagen por Resonancia Magnética , Procedimientos Neuroquirúrgicos , Estadificación de Neoplasias , Neoplasias Encefálicas/complicaciones , Neoplasias Encefálicas/cirugía
19.
Acta Neurochir (Wien) ; 146(8): 785-802, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15254801

RESUMEN

BACKGROUND: This retrospective study analyzes the clinical, neuroradiological, pathological and surgical characteristics of well-described intraventricular craniopharyngiomas with the aims of: (i) critically to review the criteria used to affirm the diagnosis of an intraventricular location (ii) defining more accurately this topographical diagnosis preoperatively, and (iii) to investigate factors influencing the surgical outcome. METHOD: Clinical, neuroradiological, pathological and surgical objective data of 104 well-described intraventricular craniopharyngiomas (IVC) reported in the literature, in addition to a new case, were analyzed. On the basis of the proofs provided for third ventricle intactness, a new topographical classification for IVC was developed, distinguishing between: (i) strict IVC, with a proved third ventricle floor integrity and (ii) non-strict IVC, without any reliable proof confirming the intactness of the third ventricle floor. Following this classification, clinical features, pathology and surgical outcome for strictly and non-strictly IVC were compared. FINDINGS: For 105 IVC compiled, 36 belonged to the strictly group and 69 to the non-strictly group. Two pathological features were associated with the non-strictly IVC group: a preferentially adamantinomatous pattern (p=0.106) and wider and tighter adherences to third ventricle margins (p=0.01). The non-strict topography was also associated with a worse postoperative outcome (p=0.046). There was a significant relationship between the surgical approach and the final outcome (p=0.05), being the translamina terminalis approach associated with the best outcome. CONCLUSIONS: Two different topographies might be considered among IVC: strict and non-strict intraventricular location. Non-strictly IVC have wider and tighter adhesions to third ventricle boundaries and this subtype is associated with a worse outcome.


Asunto(s)
Neoplasias del Ventrículo Cerebral/diagnóstico , Neoplasias del Ventrículo Cerebral/cirugía , Craneofaringioma/diagnóstico , Craneofaringioma/cirugía , Procedimientos Neuroquirúrgicos , Tercer Ventrículo/patología , Adolescente , Adulto , Anciano , Neoplasias del Ventrículo Cerebral/clasificación , Niño , Preescolar , Craneofaringioma/clasificación , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Radiografía , Estudios Retrospectivos , Tercer Ventrículo/diagnóstico por imagen , Resultado del Tratamiento
20.
Rev Neurol ; 38(6): 565-81, 2004.
Artículo en Español | MEDLINE | ID: mdl-15054722

RESUMEN

AIMS: To analyze the functional reasons justifying the existence of the blood brain barrier with an emphasis on its fundamental role supporting neuroglial coupling. DEVELOPMENT: We review in an integrated manner the contributions of different research areas in physiology and metabolism of the central nervous system which allow to understand the functional need for the existence of the blood brain barrier. In particular, we describe the physiological basis of the metabolic functional coupling and the metabolic interactions between neurons and glial cells, two properties directly derived from the presence of the blood brain barrier. Likewise the blood brain barrier is presented as an important determinant of the heterogeneous activation of cerebral tissue as detected by neuroimaging technologies as positron emission tomography and functional magnetic resonance imaging. CONCLUSIONS: The main function of the blood brain barrier is to maintain a stable composition of the extracellular milieu in nervous tissue. This allows the changes in ionic composition and neurotransmitter concentration in the extracellular milieu, to reflect indirectly the generation of action potentials and the state of neurotransmission of neuronal circuits. Glial cells induce the development of the blood brain barrier and are the main sensors of neuronal function, due to their important take up capacity for extracellular potassium and neurotransmitters. Glial homeostasis of the extracellular milieu is circuit specific, limiting the functional metabolic coupling to discrete regions of the brain and generating the classical pattern of heterogeneous activity in the different modules of the nervous tissue.


Asunto(s)
Barrera Hematoencefálica/fisiología , Sistema Nervioso Central/fisiología , Barrera Hematoencefálica/ultraestructura , Sistema Nervioso Central/anatomía & histología , Líquido Extracelular/química , Glucosa/metabolismo , Ácido Glutámico/metabolismo , Glutamina/metabolismo , Homeostasis , Humanos , Red Nerviosa , Neuroglía/metabolismo , Neuroglía/ultraestructura , Neuronas/metabolismo , Neuronas/ultraestructura , Potasio/metabolismo , Ácido gamma-Aminobutírico/metabolismo
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