RESUMEN
GFP mutants are known to display fluorescence flickering, a process that occurs in a wide time range. Because serine 65, threonine 203, glutamate 222, and histidine 148 have been indicated as key residues in determining the GFP fluorescence photodynamics, we have focused here on the role of histidine 148 and glutamate 222 by studying the fluorescence dynamics of GFPmut2 (S65A, V68L, and S72A GFP) and its H148G (Mut2G) and E222Q (Mut2Q) mutants. Two relaxation components are found in the fluorescence autocorrelation functions of GFPmut2: a 10-100 micros pH-dependent component and a 100-500 micros laser-power-dependent component. The comparison of these three mutants shows that the mutation of histidine 148 to glycine induces a 3-fold increase in the protonation rate, thereby indicating that the protonation-deprotonation of the chromophore occurs via a proton exchange with the solution mediated by the histidine 148 residue. The power-dependent but pH-independent relaxation mode, which is not affected by the E222Q and H148G mutations, is due to an excited-state process that is probably related to conformational rearrangements of the chromophore after the photoexcitation, more than to the chromophore excited-state proton transfer.
Asunto(s)
Proteínas Fluorescentes Verdes/química , Sustancias Luminiscentes/química , Fotones , Protones , Simulación por Computador , Ácido Glutámico/química , Histidina/química , Concentración de Iones de Hidrógeno , Mutación , Conformación Proteica , Serina/química , Espectrometría de Fluorescencia , Treonina/químicaRESUMEN
Aim of this study was to evaluate through an audit tool the appropriateness of interferon-alpha (IFN-alpha) prescribing in a teaching hospital. The records of all patients (n.665) treated with IFN-alpha since 1991 were reviewed and the data concerning diagnosis and treatment collected using a standardized from. The data were submitted for peer review to a panel which included the representatives of the different medical specialties which actually prescribed the drug, external experts and members of the health management board of the hospital. The following points were discussed:-adherence to accepted therapeutic indications:-accuracy of the diagnosis prior to treatment:-scheduled doses:-criteria defining non-responders;-length of treatment and criteria for discontinuation. At the end of the study a questionnaire for evaluation of the audit was submitted to all participants. Most patients were treated according to a diagnosis of chronic hepatitis (HCV, n.448; HBV, n.54; HDV, n.22); other indications were chronic myeloid leukemia, thrombocythemia, polycythemia vera, Kaposi's sarcoma, condylomata, melanoma and mycosis fungoides. All indications were approved by the panel: no patient was treated outside established indications (85.6%) or a clinical trial protocol (14.4%). Standard schedules were initially applied to each indication, and were adjusted if needed according to the clinical response. In conclusion, the audit showed that IFN-alpha was correctly prescribed in our teaching hospital; the procedure was well accepted and its application may be useful in modifying prescribing attitudes.
Asunto(s)
Interferón-alfa/uso terapéutico , Auditoría Médica , Utilización de Medicamentos , Hospitales de Enseñanza , Humanos , ItaliaRESUMEN
The Authors report about the case of one patient with stroke picture of aphasia and right pyramidal deficiency hemisyndrome evidencing at the CT a picture of multiple bilateral malacic areas associated with a picture of bilateral megadolichosiphon. The later tomographic controls evidenced the occurrence of a right latero-supra-sellar expansive injury compatible with a picture of giant aneurysm of the homolateral carotidal siphon. The Authors analyze the clinical, neuroradiological and anatomopathologic findings in the light of the present publications in the recent literature.
Asunto(s)
Aneurisma Intracraneal/diagnóstico por imagen , Angiografía Cerebral , Humanos , Aneurisma Intracraneal/patología , Masculino , Persona de Mediana Edad , Tomografía Computarizada por Rayos XRESUMEN
Personal experience about a correlative study on ultrasonographic and angiographic methods executed on carotid artery is reported. Usual techniques are described and result discordances are considered. Stenosis level is subdivided in four different types: normal, less than 45, 45-75%, greater than 75%. Authors examine in which stenosis range one technique can be superimposed on the other one and show limits and possibilities. Moreover complementary and interdependence position of these two techniques are stressed with respect to atherosclerotic disease study.
Asunto(s)
Arteriosclerosis/diagnóstico , Enfermedades de las Arterias Carótidas/diagnóstico , Arteria Carótida Externa/patología , Ultrasonografía , Arteria Carótida Externa/diagnóstico por imagen , Estudios de Evaluación como Asunto , Humanos , Radiografía , Ultrasonografía/métodosRESUMEN
Cerebral arterial spasm following subarachnoid hemorrhage can be responsible for secondary neurological deficits and can influence history, prognosis, and results of surgical treatment. The demonstration of vasospasm can be important for therapy. The use of I-123 HIPDM and SPECT in evaluating regional cerebral blood flow showed the effects on cerebral perfusion of diffuse arterial spasm in a case of subarachnoid hemorrhage and its recovery. There was a parallel with clinical neurological status.