RESUMEN
2-Methyladenosine-substituted analogues of 2-5A, p5'A2'p5'A2'p5'(me2A), p5'(me2A)2'p5'A2'p5'A, and p5'(me2A) 2'p5'(me2A)2'pS'(me2A), were prepared via a modification of a lead ion-catalyzed ligation reaction. These 5'-monophosphates were subsequently converted into the corresponding 5'-triphosphates. Both binding and activation of human recombinant RNase L by various 2-methyladenosine-substituted 2-5A analogues were examined. Among the 2-5A analogues, p5'A2'p5'A2'p5'(me2A) showed the strongest binding affinity and was as effective as 2-5A itself as an activator of RNase L. The CD spectra of both p5'(me2A)2'p5'A2'p5'A and p5'A2'p5'A2'p5'(me2A) were superimposable on that of p5'A2'p5'A2'p5'A, indicative of an anti orientation about the base-glycoside bonds as in naturally occurring 2-5A.
Asunto(s)
Adenosina Monofosfato/química , Adenosina Monofosfato/farmacología , Adenosina/análogos & derivados , Endorribonucleasas/efectos de los fármacos , Oligorribonucleótidos/química , Oligorribonucleótidos/farmacología , Adenosina/química , Adenosina/farmacología , Adenosina Monofosfato/análogos & derivados , Sitios de Unión , Catálisis/efectos de los fármacos , Dicroismo Circular , Endorribonucleasas/metabolismo , Humanos , Espectroscopía de Resonancia Magnética , Conformación de Ácido Nucleico , Unión Proteica , Proteínas Recombinantes/efectos de los fármacos , Proteínas Recombinantes/metabolismo , Relación Estructura-ActividadRESUMEN
Contrast-enhanced MR angiography (ceMRA) allows practical carotid arteriography without venous enhancement. However, it requires some intricate preparation such as a test bolus of the contrast agent or determination of the tracking volume even in the automatic triggering Smartprep system. The purpose of this study was to obtain carotid ceMRA without any preparation by means of a repeated multiple ultrashort three-dimensional MRA sequence (e3d56), i.e., time-resolved MRA (trMRA). Twenty-three patients underwent sagittal trMRA using a 1.0-Tesla superconducting unit. Multiple projection angiograms are acquired in three contiguous phases with a time resolution of 6 seconds per slab, including 10 partitions, after a bolus injection of 10 ml of Gd-DTPA followed by 20 ml of saline at 2 ml/sec. In all patients, the signal from the arteries could be separated from that of the veins in at least one phase. Carotid trMRA with 6-sec temporal resolution is a reliable technique for selective arteriography, avoiding the necessity of timing the contrast agent bolus.
Asunto(s)
Arterias Carótidas/patología , Angiografía por Resonancia Magnética/métodos , Adulto , Anciano , Enfermedades de las Arterias Carótidas/diagnóstico , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
UNLABELLED: With increased use of platelet concentrate (PC) in recent years, adverse reactions to PC transfusion have received much clinical attention. Most of these reactions stem from white blood cells (WBC) contaminating the transfused PC. Several are thought to be preventable by removing WBC before PC storage. METHODS: We routinely filtered apheresis PC either during collection or immediately afterwards and monitored various indicators of platelet quality during storage. After transfusion to patients, transfusion efficacy and the type, severity, and frequency of posttransfusion side effects were compared with those of a control group in which PC was filtered at the bedside. RESULTS: Prestorage-filtered PC contained an average of 3.1+/-0.7 x 10(11) platelets and 0.9+/-1.2 x 10(6) contaminating leukocytes. Measurement of platelet function and metabolic indicators revealed normal values throughout the storage period. CD62 measurement revealed no undue platelet activation after filtration or during the storage period. Cytokine, histamine, bradykinin, and complement levels showed no significant increase after filtration or during storage. Transfusion efficacy and overall side effect incidence rates were similar for the prestorage- and bedside-filtered groups, but reactions of the bedside-filtered group included serious reactions such as breathing difficulties and shock. No serious reactions were noted in the prestorage-filtered group. CONCLUSION: Filtering PC before storage has no adverse effect on PC quality and may reduce the severity of post transfusion side effects.
Asunto(s)
Separación Celular/métodos , Transfusión de Plaquetas , Plaquetoferesis/métodos , Plaquetas/fisiología , Conservación de la Sangre/métodos , Estudios de Evaluación como Asunto , Femenino , Humanos , Factores Inmunológicos/sangre , Recuento de Leucocitos , Leucocitos/citología , Masculino , Activación Plaquetaria/fisiología , Recuento de Plaquetas , Transfusión de Plaquetas/efectos adversosRESUMEN
An 87-year-old female was admitted with left chest pain and dyspnea in January 1989. The chest X-ray film revealed complete atelectasis of the left lung. Bronchoscopic observation revealed a tumor which was bleeding easily at left main bronchus. Cytological findings of the bronchial aspirates showed small cell lung cancer. Because she was old and had some complications, she was difficult to treat by standard combination chemotherapy. Only etoposide at 150 mg/day was administered orally for 3 days (first course). After the first course the whole lung atelectasis improved; and after the second course (etoposide at 150 mg/day for 4 days) the tumor of the left main bronchus disappeared under endoscopic examination. Malignant cells were not detected in the bronchial aspirates and biopsy specimens. No severe side effect except for alopecia and mild gastrointestinal symptoms such as nausea and vomiting was noted. Myelosuppression was not evident. This case suggested that etoposide administered orally is useful in the treatment of small cell lung cancer especially in elderly patients with complications.