Asunto(s)
Medios de Contraste , Imagen por Resonancia Magnética/métodos , Melaninas , Animales , Medios de Contraste/química , Medios de Contraste/toxicidad , Relación Dosis-Respuesta a Droga , Estabilidad de Medicamentos , Gadolinio/química , Gadolinio/toxicidad , Humanos , Aumento de la Imagen , Hierro/química , Hierro/toxicidad , Melaninas/química , Melaninas/toxicidad , Ratones , Ratones Desnudos , Polímeros , Relación Estructura-Actividad , Especificidad por SustratoRESUMEN
The EMIT 700 and EMIT II assays for marijuana, cocaine, opiates, barbiturates, and phencyclidine, as performed on a Hitachi 717 Analyzer, were compared with Roche Abuscreen RIA tests for high-volume drug abuse screening. The EMIT II kits offer some advantages over the EMIT 700 kits for testing large work loads. The EMIT II marijuana test in particular exhibits a calibration curve that promises improved ability to separate negative from positive samples due to the increased absorbance rate separation between the negative and cutoff calibrators. Both EMIT formulations are preferable in terms of speed and ease of analysis in comparison with our laboratory's current RIA procedures. Over 50,000 urine samples were screened by EMIT 700 and RIA and by EMIT II and RIA. The performance of both EMIT assays was approximately equivalent to RIA in terms of their ability to detect urine samples that confirmed positive for cocaine and opiates. Both EMIT assays detected approximately 90% of the urine samples screened positive by RIA and confirmed positive for marijuana. Both EMIT assays performed better than RIA in detecting confirmed-positive barbiturate samples.
Asunto(s)
Técnica de Inmunoensayo de Enzimas Multiplicadas , Detección de Abuso de Sustancias/métodos , Calibración , Cromatografía de Gases y Espectrometría de Masas , Humanos , Valor Predictivo de las Pruebas , RadioinmunoensayoRESUMEN
The importance of contrast agents in enhancing diagnoses from magnetic resonance images has been established in numerous cases. However, the development of a potent tissue-specific contrast agent, as a sensitive probe for early detection and investigation of the physiological characteristics of a tumor, has not yet been realized in MR imaging (MRI). In nuclear scintigraphy the technique has been demonstrated; however, the poor spacial resolution inherent to the modality and the substantial dose of radioactivity administered to the patient has hindered its widespread use. This article will review the different classes of contrast agents in MRI, with special focus on the strategies involved in the development of targeted tissue-specific MRI contrast agents for the early detection of breast cancer. The features of a new class of contrast agents for targeted MR imaging will be described. Gadolinium-containing melanin polymers (GMP's) have been synthesized as MR contrast agents in our laboratory. These GMP's demonstrate significantly higher relaxivities than any other paramagnetic contrast agents reported; consequently, they are extremely effective contrast enhancing, imaging agents by themselves. The successful coupling of these potent GMP's to a monoclonal antibody specific for breast carcinoma, the 323/A3 monoclonal antibody, suggests that in vivo tissue-specific MR imaging, at the receptor level, will become feasible in the near future.
Asunto(s)
Neoplasias de la Mama/diagnóstico , Medios de Contraste , Imagen por Resonancia Magnética/métodos , Gadolinio , Humanos , Mamografía/métodosRESUMEN
The newest formulation of the EMIT assay for drugs of abuse, EMIT II, and a new immunoassay, OnLine, using the kinetic interaction of microparticles in solution methodology, were evaluated for marijuana, cocaine, opiates, barbiturates, and phencyclidine. Both types of immunoassays were performed on an Hitachi 717 analyzer. Calibration curves, the degree of separation between negative and cutoff calibrators, precision, probability of carryover from positive to negative samples, and overall ease and speed of analysis were evaluated. EMIT II and OnLine were compared with RIA tests for the five drugs to determine each assay's ability to detect samples which confirm positive by GC/MS. The RIA and OnLine marijuana tests detected > 99% of confirmed positive samples while EMIT II detected about 90%. All three immunoassays performed equivalently for cocaine and opiates, each assay detecting at least 98% of positives. Barbiturates showed the greatest disparity with OnLine detecting 96%, EMIT II 85%, and RIA 79% of confirmed positive samples. Too few phencyclidine positive samples were detected for a method comparison study. The fully automated EMIT II and OnLine assays are preferable for a variety of reasons to our laboratory's current semi-automated RIA tests for large volume urine testing. The immunoassays offer comparable performance for some drugs but not for others.
Asunto(s)
Cannabis , Cocaína/orina , Inmunoensayo/métodos , Opio/orina , Calibración , Humanos , Técnicas para Inmunoenzimas , Radioinmunoensayo , Sensibilidad y Especificidad , Factores de TiempoRESUMEN
The selection of sites to store high-level radioactive waste will require more than technical decisions; an acceptable site must gain widespread public support. Ad hoc approaches have recently served as a stimulus to overcome institutional inertia in radioactive waste management, as exemplified by the Interagency Review Group and the State Planning Council for Radioactive Waste Management, but ad hoc approaches have not characteristically succeeded in resolving intense conflicts. Acceptable sites can best be established through traditional processes of legal and scientific advocacy, and their ultimate legitimacy will depend on the proper use of established democratic processes.
RESUMEN
Salivary genetic marker systems, especially the Pm and Ph systems, were studied in Caucasians. The gene frequencies obtained were, Pm+ = 0.14 and Pm- = 0.86. A variant polymorphic protein (Ph) present in the Japanese population was not observed in Caucasians.