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1.
Rev. esp. enferm. dig ; 111(4): 301-307, abr. 2019. tab, graf
Artigo em Inglês | IBECS | ID: ibc-189927

RESUMO

Introduction: non-alcoholic fatty liver disease is one of the most prevalent liver disorders in the developed world. Currently, there is no approved pharmacological therapy except for lifestyle intervention. Therefore, there is a need to increase the knowledge of preclinical models in order to boost novel discoveries that could lead to a better therapeutic management. Material and methods: this study characterized the effects of two different diets, a long-term high-fat high-fructose diet (HF-HFD) and a choline-deficient, methionine supplemented high-fat diet (CDA-HFD) in C57BL/6J mice for 52 weeks or 16 weeks, respectively. Body weight, lipid and hepatic profile were analyzed and liver histology was subsequently evaluated. Results: HF-HFD animals had an increased body weight and total cholesterol levels, whereas the opposite occurred in CDA-HFD. Both HF-HFD and CDA-HFD animals had higher ALT and AST levels. With regard to histology findings, HF-HFD and CDA-HFD diets induced an increased collagen deposit and intrahepatic steatosis accumulation. Conclusion: in conclusion, the comparison of these models aided in the selection of a long-term, more physiological model for physiopathology studies or a more rapid NASH model for novel molecule testing


No disponible


Assuntos
Animais , Camundongos , Fígado Gorduroso/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Cirrose Hepática/metabolismo , Modelos Animais de Doenças , Alanina Transaminase/metabolismo , Aspartato Aminotransferases/metabolismo , Dieta Hiperlipídica/efeitos adversos , Colina/metabolismo , Edulcorantes/metabolismo , Metionina/metabolismo
4.
Rev. lab. clín ; 10(4): 212-216, oct.-dic. 2017. tab, ilus
Artigo em Espanhol | IBECS | ID: ibc-166853

RESUMO

La homocistinuria es un error innato del metabolismo de la metionina con una alta tasa de morbimortalidad. Mutaciones en la cistationina beta-sintetasa son la causa más frecuente de homocistinuria, conocida esta como homocistinuria clásica. Hay descritas más de 150 mutaciones diferentes, de las cuales la más prevalente en España es la T191M. La detección mediante cribado neonatal puede prevenir las complicaciones más graves de la enfermedad y posibilitar un desarrollo cognitivo normal. Presentamos un caso de homocistinuria clásica debida a la mutación T353M, con fenotipo no respondedor a piridoxina (AU)


Homocystinuria is an inherited disorder of methionine metabolism, and has a high morbidity-mortality rate. Mutations in the cystathionine beta-synthase gene are the most common cause of homocystinuria, known as classic homocystinuria. More than 150 mutations have been described, with T191M being the most prevalent in Spain. Neonatal identification by newborn screening may prevent severe complications, and allow normal intellectual development. A case is presented of pyridoxine non-responsive homocystinuria due to T353 mutation (AU)


Assuntos
Humanos , Feminino , Adolescente , Homocistinúria/diagnóstico , Cistationina beta-Sintase/análise , Cistationina beta-Sintase/deficiência , Hiper-Homocisteinemia/complicações , Hiper-Homocisteinemia/diagnóstico , Hiper-Homocisteinemia/etiologia , Metionina/metabolismo , Triagem Neonatal/métodos , Fibrinólise/fisiologia
5.
Int. microbiol ; 20(3): 149-150, sept. 2017.
Artigo em Inglês | IBECS | ID: ibc-171333

RESUMO

The L-forms of amino acids are used in all kingdoms of life to synthesize proteins. However, the bacterium Vibrio cholerae, the causative agent of cholera, produces D-amino acids which are released to the environment at millimolar concentrations. We baptized these D-amino acids as non-canonical D-amino acids (NCDAAs) since they are different from those (i.e. D-alanine and D-glutamate) normally present in the bacterial cell wall. In V. cholerae, production of NCDAAs relies on the BsrV enzyme, a periplasmic broad spectrum racemase. BsrV multispecific activity, produces of a wide range of distinct D-amino acids. Using a combination of genetics and molecular physiology approaches we have demonstrated that NCDAAs target different cellular processes which may function as part of a cooperative strategy in vibrio communities to protect non-producing members from competing bacteria. Because NCDAA production is widespread in bacteria, we anticipate that NCDAAs are relevant modulators of microbial subpopulations in diverse ecosystems (AU)


No disponible


Assuntos
Humanos , Masculino , Feminino , Aminoácidos/análise , Vibrio cholerae/isolamento & purificação , Cólera/etiologia , Alanina/análise , Parede Celular/microbiologia , Periplasma/microbiologia , Metionina/análise , Metionina/isolamento & purificação , Arginina/análise
6.
Neurología (Barc., Ed. impr.) ; 32(7): 463-468, sept. 2017. graf
Artigo em Espanhol | IBECS | ID: ibc-166251

RESUMO

Introducción: La epigenética se define como el estudio de los mecanismos que regulan la expresión génica sin modificar la secuencia de ADN, siendo entre ellos el más conocido la metilación del ADN. La esclerosis múltiple (EM) es una enfermedad de etiología no del todo conocida, en la que se plantea que la participación de factores ambientales sobre individuos con una determinada predisposición genética, pueden resultar claves para el desarrollo de la enfermedad. Es en esta intersección entre la predisposición genética y los factores ambientales donde la metilación del ADN puede desempeñar un papel patogénico. Desarrollo: Realizamos una revisión bibliográfica de los efectos que los factores de riesgo ambiental para el desarrollo de EM pueden ejercer sobre los distintos mecanismos epigenéticos, así como la implicación que presentan dichas modificaciones en el desarrollo de la enfermedad. Conclusión: El conocimiento de las modificaciones epigenéticas involucradas en la patogenia de la EM abre una nueva vía de investigación para la identificación de potenciales biomarcadores, así como para la búsqueda de nuevas dianas terapéuticas (AU)


Introduction: Epigenetics is defined as the study of the mechanisms that regulate gene expression without altering the underlying DNA sequence. The best known is DNA methylation. Multiple Sclerosis (MS) is a disease with no entirely known etiology, in which it is stated that the involvement of environmental factors on people with a genetic predisposition, may be key to the development of the disease. It is at this intersection between genetic predisposition and environmental factors where DNA methylation may play a pathogenic role. Development: A literature review of the effects of environmental risk factors for the development of MS can have on the different epigenetic mechanisms as well as the implication that such changes have on the development of the disease. Conclusion: Knowledge of epigenetic modifications involved in the pathogenesis of MS, opens a new avenue of research for identification of potential biomarkers, as well as finding new therapeutic targets (AU)


Assuntos
Humanos , Esclerose Múltipla/genética , Metilação de DNA/genética , Epigênese Genética , Regulação da Expressão Gênica/genética , Predisposição Genética para Doença , Vitamina B 12/metabolismo , Homocisteína/metabolismo , Metionina/metabolismo , Fatores de Risco , Fumar/efeitos adversos , Infecções por Vírus Epstein-Barr/complicações
8.
Rev. esp. med. nucl. imagen mol. (Ed. impr.) ; 36(2): 85-90, mar.-abr. 2017. tab, ilus
Artigo em Espanhol | IBECS | ID: ibc-160779

RESUMO

Objetivo. Valorar la contribución de la PET con 11C-metionina en la diferenciación precoz entre recurrencia tumoral y radionecrosis en pacientes tratados de gliomas de alto grado. Método. Treinta pacientes tratados de glioma (grado iii/iv) con cirugía/radioterapia/quimioterapia (5-18 meses) con RM indeterminada. A todos se les realizó estudio de PET con 11C-metionina (<15 días tras RM) con análisis visual (grado de intensidad y morfología de captación), cuantificación (relación SUV máximo lesión/SUV medio fondo) y corregistro PET/RM (3D-Flair). El manejo de los pacientes se decidió en el comité de neurooncología: seguimiento clínico-imagen, tratamiento de segunda línea o cirugía. Resultados. Veintitrés estudios de PET con 11C-metionina fueron visualmente positivos. La morfología fue: 15 focales, 4 difusos y 4 anulares. Tres de los focales fueron resecados (AP+). En 16 se realizó terapia de segunda línea (11 respuesta, 5 progresión). En los 4 de morfología anular se decidió seguimiento, con progresión en 2 (verdaderos positivos) y libres de enfermedad en 2 (6 y 7 meses después) (falsos positivos). Siete estudios de PET con 11C-metionina fueron visualmente negativos, todos ellos libres de enfermedad (3-12 meses). La relación SUV lesión/fondo en la recurrencia tumoral fue de 2,79±1,35 mientras que en la radionecrosis fue de 1,53±0,39 (p<0,05). Con umbral de corte SUV lesión/fondo de 2,35 se obtuvo una sensibilidad y especificidad del 90,5 y 100%. Conclusión. La valoración de la PET con 11C-metionina, con análisis visual, cuantitativo y corregistro PET/RM muestra un papel complementario en los pacientes con RM no concluyente, permitiendo una diferenciación precoz entre recurrencia tumoral y radionecrosis, que ayuda a la individualización de la terapia (AU)


Objective. To evaluate the contribution of 11C-Methionine PET in the early differentiation between tumour recurrence and radionecrosis in patients treated for a high grade glioma. Method. The study included 30 patients with glioma (III/IV grade) treated with surgery/radiotherapy/chemotherapy (5-8 months) and with an indeterminate MRI. All patients underwent a 11C-Methione PET (within 15 days of MRI) and studies were visually analysed (intensity and morphology of uptake), quantified (SUV max/SUV mean background), and coregistered to MRI (3D-Flair). Patient management was decided by the neuro-oncology committee to clinical and imaging follow-up, second-line treatment, or surgery. Results. There were 23 11C-Methionine PET studies visually positive. Morphology of uptake was focal in 15, diffuse in 4, and ring-shaped in 4. Three out of the focal uptake cases underwent resection (Histopathology +). Sixteen underwent second-line therapy (11 responded; 5 progressed). The 4 cases with ring-shaped uptake were followed-up, and progression was found in 2 (true-positive), and disease-free in 2 (follow-up of 6 and 7 months, respectively) (false-positive). Seven out of 11C-Methionine studies PET were visually negative, and all of them were disease-free (follow-up of 3-12 months). SUV lesion/background was 2.79±1.35 in tumour recurrence, and 1.53±0.39 in radionecrosis (P<.05). Taking into account a SUV lesion/background threshold of 2.35, the sensitivity and specificity values were 90.5% and 100%, respectively. Conclusion. Visual analysis, quantitative and PET/MRI coregistration of 11C-Methionine PET showed their complementary role in patients with indeterminate MRI results, thus allowing early differentiation between tumour recurrence and radionecrosis, and helping in the individual therapy approach (AU)


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Metionina/administração & dosagem , Metionina/análise , Tomografia por Emissão de Pósitrons/instrumentação , Tomografia por Emissão de Pósitrons/métodos , Glioma , Recidiva , 24960/métodos , Análise Estatística , Encefalomalacia
9.
An. R. Acad. Farm ; 82(2): 231-246, abr.-jun. 2016. ilus, graf
Artigo em Inglês | IBECS | ID: ibc-154642

RESUMO

S-adenosylmethionine is a very versatile compound known to be involved in as many reactions as ATP. Its role as methyl donor is key for the production of a large variety of molecules, as well as, for the modification of proteins and nucleic acids. Therefore, it is not surprising that impairments in the methionine cycle are found in many diseases including liver pathologies, Alzheimer or rare diseases. In most of these cases, reductions in S-adenosylmethionine concentrations correlate with the presence of oxidative stress. This fact prompted the study of a putative redox regulation of the methionine cycle that has been focused especially on methionine adenosyltransferases, the enzymes that synthesize S-adenosylmethionine. This review is intended to provide an outline of the new levels at which the redox control of these enzymes is exerted and their importance for liver pathology, a field in which we have made several key contributions


La S-adenosilmetionina es un compuesto muy versátil, conocido por participar en casi tantas reacciones como el ATP. Su papel como donante de grupos metilo es esencial para la producción de una gran variedad de moléculas, así como para la modificación de proteínas y ácidos nucleicos. Por ello, no resulta sorprendente que se hayan detectado alteraciones en el ciclo de la metionina en una gran variedad de patologías, que incluyen desde enfermedades hepáticas hasta el Alzheimer o enfermedades raras. En muchos de estos casos la reducción de los niveles de S-adenosilmetionina se acompaña de la presencia de estrés oxidativo. Este hecho ha inducido el estudio de una posible regulación redox del ciclo de la metionina, que se ha enfocado principalmente a las metionina adenosiltransferasas, que son las enzimas encargadas de la síntesis de S-adenosilmetionina. Esta revisión pretende dar una visión global de los nuevos niveles a los que se ejerce el control redox de estas enzimas y su importancia en hepatopatología, campo en el cual hemos realizado importantes aportaciones


Assuntos
Humanos , S-Adenosilmetionina/síntese química , Oxirredução , Hepatopatias/tratamento farmacológico , Metionina , Estresse Oxidativo/fisiologia
10.
J. physiol. biochem ; 71(4): 659-667, dic. 2015.
Artigo em Inglês | IBECS | ID: ibc-145719

RESUMO

Oxidative stress plays an important role in cardiovascular diseases. The study investigated the effects of dietary palm tocotrienol-rich fraction on homocysteine metabolism in rats fed a high-methionine diet. Forty-two male Wistar rats were randomly assigned to six groups. Five groups were fed with high-methionine diet (1 %) for 10 weeks. Groups 2 to 5 were also given dietary folate (8 mg/kg) and three doses of palm tocotrienol-rich fraction (30, 60 and 150 mg/kg) from week 6 to week 10. The last group was only given basal rat chow. High-methionine diet increased plasma homocysteine after 10 weeks, which was prevented by the supplementations of folate and high-dose palm tocotrienol-rich fraction. Hepatic S-adenosyl methionine (SAM) content was unaffected in all groups but S-adenosyl homocysteine (SAH) content was reduced in the folate group. Folate supplementation increased the SAM/SAH ratio, while in the palm tocotrienol-rich fraction groups, the ratio was lower compared with the folate. Augmented activity of hepatic cystathionine Beta-synthase and lipid peroxidation content by high-methionine diet was inhibited by palm tocotrienol-rich fraction supplementations (moderate and high doses), but not by folate. The supplemented groups had lower hepatic lipid peroxidation than the high-methionine diet. In conclusion, palm tocotrienol-rich fraction reduced high-methionine-induced hyperhomocysteinaemia possibly by reducing hepatic oxidative stress in high-methionine-fed rats. It may also exert a direct inhibitory effect on hepatic cystathionine Beta-synthase (AU)


No disponible


Assuntos
Ratos , Animais , Tocotrienóis/farmacocinética , Metionina , Cistationina beta-Sintase , Fígado/fisiologia , Homocisteína/análise , S-Adenosil-Homocisteína/farmacocinética , S-Adenosilmetionina , Metionina Adenosiltransferase
12.
Rev. esp. med. nucl. imagen mol. (Ed. impr.) ; 33(4): 234-236, jul.-ago. 2014. ilus
Artigo em Inglês | IBECS | ID: ibc-125260

RESUMO

Carbon-11 methionine (11C-Methionine) is a radio-labeled amino acid currently utilized in Positron Emission Tomography (PET) for imaging primary and metastatic brain tumors. Its clinical use relies mostly on oncologic applications, but the tracer has the potential to investigate other non-malignant conditions. So far, very limited evidence concerns the use of 11C-Methionine in patients suffering from seizure; however, the tracer can find a proper utilization in this setting especially as a diagnostic complement to 18F-Fluorodeoxyglucose (18F-FDG). Herein we report the case of a 57-year-old patient presenting with epileptic crises secondary to a brain metastasis from bladder carcinoma, who was investigated in our institution with 11C-Methionine PET. The scan documented the disease recurrence in the left parietal lobe associated with a diffused tracer uptake in the surrounding cerebral circumvolutions, derived from the comitial status. After surgical removal of the metastatic lesion, the patient experienced a complete recovery of symptoms and no further onset of secondary seizure (AU)


La 11C-metionina es un aminoácido radiomarcado que se utiliza actualmente en la tomografía por emisión de positrones (PET) para obtener imágenes de tumores cerebrales primarios y metastáticos. Su aplicación clínica más extendida es la oncología, pero tiene el potencial de investigar otras situaciones no oncológicas. Hasta el momento existe una limitada evidencia del uso de 11C-metionina en pacientes con crisis convulsiva; sin embargo, el radiotrazador puede tener utilidad en este campo especialmente como complemento diagnóstico de la 18F-fluorodeoxiglucosa (18F-FDG). Presentamos el caso de un paciente de 57a˜nos de edad con crisis epilépticas secundarias a metástasis cerebrales de un carcinoma de vejiga que fue explorado en nuestra Institución con 11C-metionina PET. El estudio demostró la recidiva de la enfermedad en el lóbulo parietal izquierdo asociada con captación difusa en las circunvoluciones cerebrales de alrededor, derivada del status comicial. Después de la extirpación quirúrgica de la metástasis cerebral, el paciente experimentó una recuperación completa de los síntomas sin posterior inicio de crisis convulsivas secundarias (AU)


Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Epilepsia/diagnóstico , Metionina , Tomografia por Emissão de Pósitrons/métodos , Neoplasias Encefálicas , Fluordesoxiglucose F18 , Metástase Neoplásica , Neoplasias da Bexiga Urinária/patologia
13.
Arch. esp. urol. (Ed. impr.) ; 67(6): 557-564, jul. 2014. tab
Artigo em Espanhol | IBECS | ID: ibc-125889

RESUMO

La polineuropatia amiloidea portuguesa (FAP) tipo I, fue observada por primera vez en 1939 y descrita en 1951 por Corino Andrade. La FAP es una enfermedad rara autonómica dominante, causada por una mutación genética del cromosoma 18, y caracterizada por la variación del la transretina, donde la valina es sustituida por metionina en la posición 30 (ATTRV 30 M) afectando principalmente a adultos jóvenes. La positiviadad de ATTRV 30 M no implica enfermedad. La enfermedad esta presente unicamente cuando el ATTR 30 M se encuentra en la sangre. Las manifestaciones de la FAP en el suelo pelvico y sistema genitourinario, son frecuentes al comienzo de la enfermedad. La diversidad fenotípica puede depender de diversos factores, modulando la mutación TTR, tal como penetración incompleta e influencia del ambiente. Las alteraciones funcionales del tracto urinario inferior aparecen en primer lugar en la fase de llenado vesical, principalmente con sensación vesical disminuida, y asociada con una afectación de la contractilidad del detrusor en la fase del vaciado. En este contexto aparece una micción descompensada, con residuos postmiccionales altos, incrementando la comorbilidad, principalmente de infecciones del tracto urinario e insuficiencia renal crónica. Este estudio describe las disfunciones del tracto urinario inferior en portadores positivos de ATTRV 30 M, sobre todo durante el periodo asintomático y estadios tempranos de la enfermedad, así como expone su asociación con la evolución clínica. En la fase preliminar del estudio, la disfunción del tracto urinario inferior en las mujeres con FAP, puede presentarse como una manifestación temprana en pacientes asintomáticos. La flujometría y la medida del residuo postmiccional son test no invasivos, y de bajo coste, que deberían hacerse durante la evaluación inicial rutinaria. La disminución de la sensibilidad vesical y afectación de la contractilidad del detrusor pueden considerarse como marcadores iniciales de la FAP. El factor neurogénico (elemento aferente) parece ser de naturaleza mecánica con repercusiones miogénicas. Esto último agrava un detrusor hipoactivo secundario a una neuropatía parasimpatica eferente e infiltración amiloide de la pared vesical. Un diagnostico precoz, así como una terapeutica temprana podrían evitar una enfermedad renal terminal (AU)


Type 1 Portuguese Familial Amyloid Polyneuropathy was first observed in 1939 and described in 1951 by Corino Andrade. FAP is a rare autosomal dominant disease caused by a mutant gene in chromosome 18, characterized by a variant transthyretin in which valine is substituted for methionine at position 30 (ATTR V30M), affecting mainly young adults. ATTR V30M positivity does not imply disease, but the disease is only present with ATTR V30M in serum. The clinical manifestations of FAP on the pelvic floor and genitourinary system are frequent at early disease onset. Phenotypic diversity can depend on modulating agents in the deposition of the mutant TTR, such as incomplete penetration and environmental influence. Functional vesicourethral disorders appear to be primarily at the bladder filling phase, namely diminished bladder sensation, and associated with a decrease in detrusor contractility during the emptying phase. Unbalanced voiding takes place in this context, with high post-void residuals, increasing the rate of co-morbidity, namely recurrent urinary tract infections and chronic renal failure. This study describes the lower urinary tract dysfunctions in ATTR V30M positive carriers, particularly during the asymptomatic period and early stages of the disease , and additionaly it describes its association with the clinical evolution of the disease. In the preliminary phase of the study, the lower urinary tract dysfunction in FAP-women may present itself as an early manifestation in asymptomatic patients. Uroflowmetry and the evaluation of post-voiding residual volume are non-invasive and low cost tests that should be done during routine initial evaluation. Reduced bladder sensation and poor detrusor contractility may be considered initial markers of FAP. The neurogenic factor (bladder afferent neurons) appears to be mechanical in nature with myogenic repercussions. This further aggravates the bladder underactivity secondary to pelvic efferent parasympathetic neuropathy and amyloid infiltration in the bladder wall. Early diagnostic and therapeutic intervention may avoid secondary end stage renal disease (AU)


Assuntos
Humanos , Transtornos Urinários/complicações , Neuropatias Amiloides Familiares/diagnóstico , Distúrbios do Assoalho Pélvico/diagnóstico , Diagnóstico Precoce , Insuficiência Renal Crônica/prevenção & controle , Bexiga Urinaria Neurogênica/epidemiologia , Metionina/análise
14.
Rev. esp. med. nucl. imagen mol. (Ed. impr.) ; 33(2): 93-98, mar.-abr. 2014. tab, ilus
Artigo em Inglês | IBECS | ID: ibc-120941

RESUMO

Aim: To evaluate the usefulness of 11C-methionine PET/CT (MET) in the localization of the parathyroid adenomas and to compare the results with those obtained with the conventional technique in double-phase 99mTc-sestamibi scintigraphy (MIBI). We evaluated the optimal timing to acquire MET images. Material and methods: A prospective study that included 14 patients (mean age: 65.5 ± 9.7 years) with primary hyperparathyroidism (PH) who underwent surgery was performed. Mean serum iPTH was 215.8 ± 108 pg/mL and serum calcium 10.8 ± 0.9 mg/dL. MIBI (planar and SPECT) was obtained 10 min and 2–3 h after injection of 740 MBq (20 mCi) of 99mTc-sestamibi. MET was obtained 10 min and 40 min after injection of 740 MBq (20 mCi) of 11C-methionine. MIBI and MET images were visually evaluated and compared. A score for 10 min and 40 min MET images from 0 (no abnormal uptake) to 3 (intense uptake) was assigned. Results: MIBI and MET were positive and concordant in 11/14 patients and in 10 of them the parathyroid adenoma was correctly localized. In 3/14 MIBI was positive and MET negative (MIBI correctly localized the parathyroid adenoma in 2 of them). According to the timing of MET imaging acquisition, the 10 min and 40 min acquisition showed the same score in 10 patients, it was higher at 10 min acquisition in 3 and in 1 the parathyroid adenoma was only detected at 40 min acquisition. Conclusion: MIBI remains the technique of choice for the localization of parathyroid adenomas in patients with PH. MET may play a complementary role in selected patients. Delayed acquisition should be included in the MET protocol when the early acquisition is negative (AU)


Objetivos: Evaluar la utilidad de la 11C-metionina PET/TC (MET) en la localización de adenoma de paratiroides comparado con la técnica convencional en doble fase con 99mTc-sestamibi (MIBI). Evaluar el tiempo adecuado para la adquisición de imágenes MET. Material y métodos: Este estudio prospectivo incluyó 14 pacientes (edad: 65,5 ± 9,7 años) con hiperparatiroidismo primario (HPTP) sometidos a cirugía. La iPTH fue de 215,8 ± 108 pg/mL y el calcio sérico 10,8 ± 0,9 mg/dL. El MIBI (planar, SPECT) fue realizado a los 10 min y 2-3 horas tras la inyección de 740 MBq (20 mCi) de MIBI. La MET fue realizada 10 min y 40 min tras la inyección de 740 MBq (20 mCi) de MET. Las imágenes fueron evaluadas visualmente y comparadas. Las imágenes con MET a 10 min y 40 min fueron valoradas según el grado de captación (0[no captación] a 3[intensa]). Resultados: MIBI y MET fueron positivos y concordantes en 11/14 pacientes, en 10 de ellos el adenoma de paratiroides fue correctamente localizado. En 3/14 el MIBI fue positivo y la MET negativa (el MIBI localizó correctamente 2). Con respecto al tiempo de adquisición imágenes MET a los 10 min y 40 min se observó la misma puntuación en 10 pacientes, fue mayor a los 10 min en 3 y en un paciente sólo fue positivo a los 40 min. Conclusiones: El MIBI continúa siendo la técnica de elección para la localización del adenoma de paratiroides en pacientes con HPTP. La MET podría tener un papel complementario en pacientes seleccionados. La adquisición tardía de la MET debería ser incluida cuando la imagen precoz sea negativa (AU)


Assuntos
Humanos , Hiperparatireoidismo Primário , Neoplasias das Paratireoides , Metionina , Tecnécio Tc 99m Sestamibi
15.
J. physiol. biochem ; 69(3): 441-449, sept. 2013.
Artigo em Inglês | IBECS | ID: ibc-121663

RESUMO

Oxidative stress contributes to cardiovascular diseases. We aimed to study the effects of palm tocotrienol-rich fraction (TRF) on plasma homocysteine and cardiac oxidative stress in rats fed with a high-methionine diet. Forty-two male Wistar rats were divided into six groups. The first group was the control. Groups 2–6 were fed 1 % methionine diet for 10 weeks. From week 6 onward, folate (8 mg/kg diet) or palm TRF (30, 60 and 150 mg/kg diet) was added into the diet of groups 3, 4, 5 and 6. The rats were then killed. Palm TRF at 150 mg/kg and folate supplementation prevented the increase in plasma total homocysteine (4.14 ± 0.33 and 4.30 ± 0.26 vs 5.49 ± 0.25 mmol/L, p < 0.05) induced by a high-methionine diet. The increased heart thiobarbituric acid reactive substance in rats fed with high-methionine diet was also prevented by the supplementations of palm TRF (60 and 150 mg/kg) and folate. The high-methionine group had a lower glutathione peroxidase activity (49 ± 3 vs 69 ± 4 pmol/mg protein/min) than the control group. This reduction was reversed by palm TRF at 60 and 150 mg/kg diet (p < 0.05), but not by folate. Catalase and superoxide dismutase activities were unaffected by both methionine and vitamin supplementations. In conclusion, palm TRF was comparable to folate in reducing high-methionine diet-induced hyperhomocysteinemia and oxidative stress in the rats’ hearts. However, palm TRF was more effective than folate in preserving the heart glutathione peroxidase enzyme activity (AU)


Assuntos
Animais , Ratos , Tocotrienóis/farmacocinética , Homocisteína/antagonistas & inibidores , Estresse Oxidativo , Fenômenos Fisiológicos Cardiovasculares , Modelos Animais de Doenças , Substâncias Protetoras/farmacocinética , Hiper-Homocisteinemia/tratamento farmacológico , Metionina/farmacocinética
16.
Nutr. hosp ; 27(6): 2133-2138, nov.-dic. 2012. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-112203

RESUMO

La homocistinuria es un error congénito del metabolismo de la metionina que conduce al acúmulo de metionina y de su principal metabolito, homocisteína, en plasma, orina y tejidos. El acúmulo de homocisteína posee toxicidad sobre los sistemas óseo (osteoporosis), ocular (luxación del cristalino), nervioso (convulsiones, alteraciones psiquiátricas) y vascular (accidentes cerebrovasculares, enfermedad cardiovascular). Presentamos 2 casos de homocistinuria en 2 pacientes hermanos y, a continuación, revisamos las estrategias terapéuticas disponibles (AU)


Homocystinuria is a congenital disorder of methyonine metabolism that leads to increased plasmatic, urinary and tissue deposits of methyonine and its main metabolite: homocysteine. Homocysteine deposits are toxic for the skeletal system (osteoporosis), the eyes (lens dislocation), central nervous system (seizures, psychiatric disorders) and also induce vascular damage (stroke and other cardiovascular events). This article reports two patients with homocystinuria in two siblings, followed by a concise review on the therapeutic strategies available for this disorder (AU)


Assuntos
Humanos , Masculino , Adulto Jovem , Adulto , Homocistinúria/dietoterapia , Metionina , Vitamina B 6/uso terapêutico , Cistina/uso terapêutico , Ácido Fólico/uso terapêutico , Betaína/uso terapêutico
18.
J. physiol. biochem ; 66(2): 93-103, jun. 2010.
Artigo em Inglês | IBECS | ID: ibc-122833

RESUMO

No disponible


The aim of this work was to evaluate the effects of a diet depleted of amino acids (protein-free diet, or PFD), as well as the supplementation with methionine (PFD+Met), on the antioxidant status of the female mouse liver. With this purpose, cytosolic protein spots from two-dimensional non-equilibrium pH gel electrophoresis were identified by several procedures, such as mass spectrometry, Western blot, gel matching and enzymatic activity. PFD decreased the contents of catalase (CAT),peroxiredoxin I (Prx-I), and glutathione peroxidase (GPx) by 67%, 37% and 45%, respectively. Gene expression analyses showed that PFD caused a decrease in CAT (−20%) and GPx (−30%) mRNAlevels but did not change that of Prx-I. It was also found that, when compared to a normal diet, PFD increased the liver contents of both reactive oxygen species (+50%) and oxidized protein (+88%) and decreased that of glutathione (−45%). Supplementation of PFD with Met prevented these latter effects to varying degrees, whereas CAT, Prx-I and GPx mRNA levels resulted unmodified. Present results suggest that dietary amino acid deprivation deranges the liver antioxidant defences, and this can be, in part, overcome by supplementation with Met (AU)


Assuntos
Animais , Camundongos , Estresse Oxidativo/fisiologia , Aminoácidos/deficiência , Metionina/farmacocinética , Fígado , Modelos Animais de Doenças , Substâncias Protetoras/farmacocinética , Peroxirredoxinas , Catalase , Glutationa Peroxidase , Antioxidantes/farmacocinética
19.
An. pediatr. (2003, Ed. impr.) ; 72(3): 179-184, mar. 2010. tab, ilus
Artigo em Espanhol | IBECS | ID: ibc-78511

RESUMO

Introducción: El exceso de metionina puede ser causa de alteraciones del sistema nervioso central, tales como edema cerebral difuso y trastornos de la mielinización. Pacientes y método: Estudio ambispectivo observacional durante un período de 15 meses de los recién nacidos prematuros ingresados en nuestro hospital que presentaron hipermetioninemia en las pruebas de cribado neonatal por espectrometría de masas en tándem. Seguimiento evolutivo de estos neonatos hasta el año de edad con valoración de sus niveles de metionina en relación con la alimentación, parámetros somatométricos y desarrollo neurológico. Resultados: De una población de estudio de 187 neonatos pretérmino, 16 de ellos presentaron hipermetioninemia aislada. El peso y la alimentación de estos recién nacidos con una fórmula de inicio especial enriquecida en metionina está relacionada con el aumento del número de casos de hipermetioninemia aislada transitoria (el 62,6% recibieron un aporte de metionina superior a 97mg/kg/día), además se halló una correlación estadísticamente significativa entre los días que los pacientes recibían esa fórmula y el tiempo que tardaron en normalizarse las cifras de metionina en plasma (r: 0,791; p: 0,000). No observamos correlación entre las cifras máximas de metionina alcanzadas en plasma y la puntuación obtenida en el test de Brunet Lézine a los 6 meses de edad corregida. Conclusiones: Este estudio pone de relevancia la importancia del suplemento de aminoácidos, concretamente de metionina, en las leches de fórmula de los recién nacidos prematuros por la trascendencia que pueden suponer para su desarrollo neurológico (AU)


Introduction: Excess methionine can cause central nervous system disorders such as diffuse cerebral edema and disorders of myelin. Patients and method: A retrospective and prospective (ambispective) observational study in preterm newborns admitted to our hospital over a period of 15 months and who had hypermethioninemia in neonatal screening tests by tandem mass spectrometry. The progress of these infants was monitored during the first year of life, assessing their methionine levels, diet, somatometric parameters and neurodevelopment. Results: From a study population of 187 preterm infants, 16 of them showed isolated hypermethioninemia. Weight and feeding the babies with a special formula enriched with methionine is related to an increased number of cases of transient isolated hypermethioninemia (62.6% received a higher contribution of methionine than 97mg/kg/day). We also found a statistically significant correlation between the days that patients received the formula and the time it takes to normalize the levels of methionine in plasma (R 0.791, p=0.000). There was no correlation between the methionine peak reached in plasma and the score on the Brunet Lézine test, at the corrected age of 6 months. Conclusions: This study highlights the importance amino acid supplements, particularly methionine, in premature infants’ formulas due to the impact they may have on neurological development (AU)


Assuntos
Humanos , Masculino , Feminino , Recém-Nascido , Metionina/efeitos adversos , Metionina/análise , Doenças do Prematuro/diagnóstico , Recém-Nascido Prematuro , Aminoácidos Essenciais/análise , Aminoácidos Essenciais/metabolismo , Erros Inatos do Metabolismo dos Aminoácidos/epidemiologia , Nutrição Parenteral Total , Programas de Rastreamento/métodos , Sinais e Sintomas , Erros Inatos do Metabolismo dos Aminoácidos/diagnóstico , Espectrometria de Massas
20.
Rev. esp. geriatr. gerontol. (Ed. impr.) ; 44(4): 194-199, jul.-ago. 2009. ilus, tab, graf
Artigo em Espanhol | IBECS | ID: ibc-76849

RESUMO

Introducción Se sabe que la restricción de proteína o la restricción de metionina (RMet) en la dieta disminuye la producción de radicales de oxígeno (ROS) y el estrés oxidativo mitocondrial y aumenta la longevidad máxima en roedores, lo que puede explicar que estos cambios ocurran en la restricción calórica. Sin embargo, no se sabe si la restricción de otros aminoácidos está también implicada. Para aclararlo, se estudió el efecto de la restricción al 40% de todos los aminoácidos de la dieta semipurificada AIN 93G, excepto la metionina, en ratas Wistar.Material y métodos Dieciséis ratas Wistar macho de 7 semanas de edad se dividieron aleatoriamente en 2 grupos: el grupo control y el grupo restringido al 40% en los aminoácidos de la dieta, excepto la metionina. Tras 7 semanas de régimen dietético los animales se sacrificaron y se les extrajo el hígado para aislar inmediatamente las mitocondrias y medir la producción de ROS y el consumo de oxígeno en éstas. Con estos datos se calculó la fuga porcentual de radicales libres. El daño oxidativo al ADN mitocondrial se estimó como 8-oxo-7,8-dihidro-2′-deoxiguanosina por cromatografía líquida de alta resolución con detección electroquímica (HPLC-EC).Resultados Al final del período experimental se observó un descenso del peso del riñón, pero no del hígado, ni del corazón o del cerebro. La producción de ROS en mitocondrias hepáticas aisladas no se modificó ni con sustratos del complejo I (piruvato con malato o glutamato con malato) ni del complejo II (succinato). La producción máxima de ROS disminuyó significativamente con glutamato, malato y rotenona pero no con piruvato, malato y rotenona ni con succinato. No hubo cambios en el consumo de oxígeno con ningún sustrato ni en estado 4 (reposo) ni en estado 3 (fosforilante). De acuerdo con los resultados de producción de ROS, no hubo diferencias entre los grupos en el daño oxidativo al ADNm(AU)


Introduction Protein or methionine restriction in the diet is known to decrease reactive oxygen species (ROS) production and mitochondrial oxidative stress and to increase maximum longevity in rodents, which could explain how these changes also take place in dietary restriction. However, it is not known whether restriction of other amino acids is also involved. To clarify this question, we studied the effect of restricting all the amino acids, except methionine, of the semi-purified diet, AIN 93G, in Wistar rats. Material and methods Seven-week old male Wistar rats (n=16) were randomly divided into two groups: a control group and a group with 40% restriction of dietary amino acids except methionine. After 7 weeks of dietary treatment, the animals were sacrificed and their livers were extracted to isolate mitochondria immediately and measure ROS production and oxygen consumption; these data allowed the percentage of free radical leak to be calculated. Oxidative damage to mitochondrial DNA was calculated as 8-oxo-7,8-dihydro-2′-deoxyguanosine by HPLC-EC. Results At the end of the experimental period decrease in kidney weight was observed, but the weight of the liver, heart and brain was unchanged. ROS production in isolated liver mitochondria was unchanged with complex I (pyruvate/malate or glutamate/malate) or complex II (succinate) linked substrates. Maximum rates of ROS production significantly decreased with glutamate/malate+rotenone but not with pyruvate/malate+rotenone or with succinate. There were no changes in oxygen consumption with any substrate either in state 4 (resting) or in state 3 (phosphorylating). In agreement with the ROS production results, there were no differences between groups in oxidative damage to mitochondrial DNA.Conclusions Taken together with previous results concerning methionine restriction, the results obtained in the (..) (AU)


Assuntos
Animais , Masculino , Ratos , Aminoácidos/administração & dosagem , Mitocôndrias , Mitocôndrias/metabolismo , Estresse Oxidativo , Aminoácidos/farmacologia , Metionina/administração & dosagem , Metionina/farmacologia , Ratos Wistar
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