Laboratory medicine clinical examples

Method-dependent measurements can be grouped by sector. For example, in the clinical fields there are cases where some higher order reference materials are required for IVD methods, such as for determination of glucose in human serum. It is also required of reference laboratories in specific measurement methods. These issues are now under the responsibility of JCTLM (Joint Committee on the Traceability of Laboratory Medicine of CCQM). CENAM has developed a reference material for glucose and cholesterol determination in human serum, and certified by IDMS, which is under review by JCTLM for the use by reference laboratories in any country applying a reference method. 

In analyzing the spectrum of a substance, one occasionally finds a band or a shoulder that is very difficult to interpret. This band may, upon further consideration, be found to be spurious, that is, it does not belong to the sample under analysis, but is caused by an instrumental effect, the method of handling the sample, or some unexpected phenomenon. For example, it has been pointed out (Inchiosa, 1965) that certain disposable syringes used in clinical and laboratory medicine yielded water-soluble extractives. One of these substances was identified as 2-(methylthio)ben-zothiazole, which has fungistatic and insecticidal activity. Such extractives or their reaction products could show up in the infrared spectrum during a laboratory procedure. 

The first mouse monoclonal antibody specific for human CD3 was produced in 1979 and named orthoclone OKT3. Aside from its use in the laboratory, OKT3 became the first anti-CD3 antibody to be utilized in transplantation medicine, but its wider application was hampered by its immunogenic and mitogenic properties (reviewed in [6]). Consequently, humanized and engineered anti-CD3 antibodies were developed to circumvent these limitations (Table 1). Since T cells and the TCR are involved in many immunological diseases, it is not surprising that the application of CD3 antibodies is not restricted to the field of transplantation. For example, CD3 antibodies are tested in clinical studies of diseases such as autoimmune diabetes (type 1 diabetes), immune-mediated inflammatory arthritis and inflammatory bowel disease [7]. 

The determination of quantity in complex mixtures is also vital in health care and medicine. We are all familiar with the medical examinations in which a sample of blood or urine is sent to a laboratory for analysis. The procedures used have been developed by chemists, and are performed by trained chemical technicians. The high level of automation achieved by the chemists who designed these analytical procedures has greatly reduced the costs of such analyses. Clinical analysis continues to be driven by a need for better methods to detect and measure important proteins, for example, that while present in tiny amounts are relevant to our health and well-being. 

The function of clinical chemistry in toxicology (as well as in human and veterinary medicine) is to provide, via laboratory analysis, evaluations of the qualitative and quantitative characteristics of specific endogenous chemical components present in samples of blood, urine, feces, spinal fluid, and tissues. The purpose is to help identify abnormal or pathological changes in organ system functions. The most common specimens used in clinical chemistry are blood and urine, and many different tests exist to test for almost any type of chemical component in blood or urine for example, blood glucose, electrolytes, enzymes, hormones, lipids (fats), other metabolic substances, and proteins. The tests used were all initially applied to human clinical medicine, and may not possess the same utility when performed as part of nonclinical toxicity studies in a wide variety of other species. 

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