Biomedical subjects
Publications and source records attributed to J J Fernandes.
Lithium has been used in the treatment of mania since 1949. Although its effectiveness is well recognized, the mechanism by which it stabilizes manic behavior is not well understood. In addition, it has some serious toxic properties combined with a narrow therapeutic range. For this reason, monitoring of serum lithium levels is mandatory. Suggested mechanisms of action and protocols for monitoring of serum levels are presented.
During a 25-year period, four types of hepatitis-causing virus have been identified and can now be evaluated serologically. This final article in this clinical laboratory medicine series reviews routes of virus transmission and persistence and the availability of tests.
Clinical differentiation between a virus and beta-hemolytic streptococci as a cause of pharyngitis remains difficult. In the physician's laboratory, more rapid procedures using immunologic methods have replaced culture methods, traditionally requiring 2 to 3 days for identification of beta-hemolytic streptococci. Attention to the diagnostic sensitivity and specificity of these procedures will guide appropriate use.
Human immunodeficiency virus (HIV) types 1 and 2 have been associated with the acquired immunodeficiency syndrome (AIDS). The detection of HIV infections is based on the screening of serum samples for the presence of antibodies to HIV proteins. Serum samples that test positive on screening must be assayed by a confirmatory test to provide a definitive report on the presence of HIV infection. This article reviews the currently available screening and confirmatory testing procedures and their limitations.
Scientific developments in molecular biology enable clinical laboratory testing to directly examine genetic information coded in biologic specimens. These efforts, accomplished by the use of DNA probe technology in the in situ hybridization and other tests will allow for the specific identification of pathogens; recognition of genetic diseases; and the critical evaluation of the genetic basis of cancer. The authors discuss the concepts and uses of DNA testing.
The justification for blood ethanol testing springs from the ubiquitous abuse of alcoholic beverages. Those dealing with patients who abuse alcohol must understand the correlations between dose, time, blood level, and behavior. Enumerated here are the strengths of various testing methods and the requisites for legally defensible testing. The challenge remains to determine blood ethanol levels in such a manner that the results are scientifically valid and legally defensible.
During the past two decades, medicine has witnessed the decentralization of laboratory testing from the hospital into the physician's office. This article focuses on the technical aspects of the instruments now available for laboratory testing in the physician's office. Consideration is given to specific instruments, methods, and cost-benefit.
The ordering, reviewing, and interpreting of laboratory tests require recognition and familiarity with the concepts of normal values, sensitivity, specificity, predictive values, and prevalence. The significance of these test properties in clinical decision-making is explained.