RESUMEN
Magnetic resonance imaging (MRI) is a useful tool for diagnosing and monitoring progressive multifocal leukoencephalopathy (PML). Although characteristic MRI findings of PML are well known, we noted a potential new finding for this disease on susceptibility-weighted imaging (SWI). Two patients with PML were studied and followed using MRI. SWI revealed low signal intensities in U-fibers adjacent to the white matter lesions of PML. These findings progressed along with the disease progression. The cause underlying these findings remains unclear. This new finding suggests that SWI is useful for the diagnosis of PML. It can provide a helpful clue in a clinical setting.
Asunto(s)
Susceptibilidad a Enfermedades/patología , Leucoencefalopatía Multifocal Progresiva/patología , Anciano , Imagen de Difusión por Resonancia Magnética , Femenino , Estudios de Seguimiento , Infecciones por VIH/complicaciones , Humanos , Fallo Renal Crónico/complicaciones , Leucoencefalopatía Multifocal Progresiva/etiología , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Examen Neurológico , Sustancia Blanca/patologíaRESUMEN
A 35-year-old woman was admitted with subacute intellectual deterioration. Laboratory studies showed elevated total homocysteine and decreased folic acid. MRI revealed leukoencephalopathy with a posterior predominance, and hyperintensity in the pyramidal tracts on T2-weighted and FLAIR images. The enzyme assay showed a deficiency of methylenetetrahydrofolate reductase (MTHFR) activity with low residual activity of 4.2% of the mean control value in cultured fibroblasts. Sequence analysis of the MTHFR gene demonstrated two homozygous missense mutations, c.677C>T (p.Ala222Val) and c.685A>C (p.Ile225Leu). c.677C>T (p.Ala222Val) is known as a common polymorphism and c.685A>C (p.Ile225Leu) is considered to be a novel polymorphism. A diagnosis of MTHFR deficiency was made. Treatment with folic acid, vitamin B12 and B6 made significant improvement of intellectual deterioration and reduction in the total homocysteine level. They also made marked resolution of leukoencephalopathy. Posterior-predominant leukoencephalopathy was found to be an excellent marker of MTHFR deficiency, and may help to establish the diagnosis.
Asunto(s)
Ácido Fólico/administración & dosificación , Homocistinuria/complicaciones , Homocistinuria/tratamiento farmacológico , Leucoencefalopatías/tratamiento farmacológico , Leucoencefalopatías/etiología , Metilenotetrahidrofolato Reductasa (NADPH2)/deficiencia , Espasticidad Muscular/complicaciones , Espasticidad Muscular/tratamiento farmacológico , Adulto , Biomarcadores/sangre , Femenino , Ácido Fólico/sangre , Homocisteína/sangre , Homocistinuria/diagnóstico , Homocistinuria/genética , Humanos , Leucoencefalopatías/diagnóstico , Leucoencefalopatías/genética , Imagen por Resonancia Magnética , Metilenotetrahidrofolato Reductasa (NADPH2)/genética , Espasticidad Muscular/diagnóstico , Espasticidad Muscular/genética , Mutación Missense , Polimorfismo de Nucleótido Simple , Trastornos Psicóticos/complicaciones , Trastornos Psicóticos/diagnóstico , Trastornos Psicóticos/tratamiento farmacológico , Trastornos Psicóticos/genética , Resultado del Tratamiento , Vitamina B 12/administración & dosificación , Vitamina B 6/administración & dosificaciónAsunto(s)
Autoanticuerpos/sangre , Encefalitis/etiología , Neoplasias Ováricas/complicaciones , Receptores de N-Metil-D-Aspartato/inmunología , Teratoma/complicaciones , Adulto , Autoantígenos/inmunología , Encefalitis/inmunología , Femenino , Humanos , Imagen por Resonancia Magnética , Neoplasias Ováricas/inmunología , Neoplasias Ováricas/fisiopatología , Teratoma/inmunología , Teratoma/fisiopatologíaRESUMEN
Alpha-chymotrypsin-catalyzed peptide synthesis was carried out between an N-protected D-amino acid ester and an L-amino acid amide (acyl donor, 10 mM; acyl acceptor, 50 mM; enzyme, 2 mg ml(-1); pH 8). By using a highly reactive carbamoylmethyl (Cam) ester as acyl donor, the D-amino acid was incorporated into the N-terminus of the resulting dipeptide amide. N-Protected dipeptide amides bearing D-amino acids such as D-Phe, D-Leu and D-Ala at their N-terminus were synthesized in high yields (up to 80%) in 1-3 h.