Journal of the International Federation of Clinical Chemistry最新文献

Magnetic resonance spectroscopy is a powerful technique for the analysis of complex mixtures. Up to now, little of its potential in everyday clinical chemistry has been realized. An overview of the fundamentals, a discussion of the technology, and some outstanding examples of the clinical chemical research are presented. Clinical chemists are encouraged to seek out and apply this methodology to problems for which it is well suited.

Considerable interest has risen in the idea that oxidative stress is instrumental in the etiology of numerous human diseases. Oxidative stress can arise through the increased production of reactive oxygen species (ROS) and/or because of a deficiency of antioxidant defenses. Antioxidant deficiencies can develop as a result of decreased antioxidant intake (such as vitamins C and E), synthesis of enzymes (such as superoxide dismutase and glutathione peroxidase) or increased antioxidant utilization. Insufficient antioxidant enzyme synthesis may in turn be due to decreased micronutrient availability (such as selenium, magnese, copper and zinc). Of those diseases linked with oxidative stress, cardiovascular disease provides the strongest evidence for the protective role of antioxidants. A high consumption of fruit and vegetables, which are good sources of antioxidants, is associated with a lower coronary risk. More specifically, there is evidence of a reduced coronary risk in populations with high blood levels of the antioxidant nutrients, vitamins C and E. Evidence is also accumulating that diabetes, and microvascular complications associated with diabetes, involve oxidative stress and have compromised antioxidant status. In addition, patients who develop acute respiratory distress syndrome (ARDS) also exhibit clear evidence of oxidative stress. Definitive proof for active oxygen formation and oxidative cell damage being causative rather than a result of other underlying these pathologies remains elusive; however, evidence is sufficiently compelling to suggest that antioxidants are potential therapeutic agents in the above conditions.

Aging is the accumulation of changes that increase the risk of death. Aging changes can be attributed to development, genetic defects, the environment, disease, and the inborn aging process. The latter is the major risk factor for disease and death after age 28 in the developed countries. In these countries, average life expectancies at birth (ALE-B) now range from 76-79 years, 6-9 years less than the limit of about 85 years imposed by aging. Aging changes may be caused by free radical reactions. The extensive studies based on this possibility show promise of increasing the ALE-B to 85 years and beyond.

A wide range of nongovernmental organizations are involved in laboratory quality assurance at the international level. These organizations include for-profit organizations such as Murex or Randox, nonprofit organizations such as the Institute for Standardization and Documentation in Medical Laboratories (INSTAND), national professional organizations such as the National Committee for Clinical Laboratory Standards (NCCLS), regional organizations such as the Asian Pacific and Latin American Federation of Clinical Biochemists and International organizations such as the IFCC and WHO. The Interaction and roles of such organizations are discussed.

The identification of the specific mutation causing an inherited disease in a patient is the framework for the development of a rationale for therapy and of DNA-based tests for screening relatives. We present here a review of the single-strand conformational polymorphism (SSCP) method, which allows DNA fragments that have been amplified with specific primers and PCR to be scanned rapidly for any sequence variation. The general principles of the method are described, as are the major factors that must be considered in developing an optimal SSCP strategy, namely length of the PCR fragment and the temperature of the gel run. Options for sample denaturing gel characteristics and detection of DNA fragments are discussed. In addition, several modifications are presented that have been developed for high-throughput mutational analysis. The application of these techniques to screen for mutations in the LDL receptor gene in patients with familial hypercholesterolemia are described.

Each year a vast number of biomedical articles and books are published and based on the articles reviews are written. Such reviews should be performed in a systematic manner. Systematic reviewing is a new discipline with its own methods for locating, appraising, and summarizing primary studies. Such methods have also been developed for studies on diagnostic test evaluations. It is important for the laboratory disciplines to engage in this work. IFCC has established a Committee for Systematic Reviewing in Laboratory Medicine. This committee will work to promote the understanding, the use and the performance of systematic reviewing.

The presence of a serum and/or urinary monoclonal immunoglobulin (monoclonal component, MC), or its subunits, heavy and light chains produced by a B cell clone in serum and/or urine characterizes a wide group of conditions called monoclonal gammapathies (MG). In most instances, the MG is clinically silent, and remains so throughout life. However, the clone may be, or will become, clinically overt because of its proliferation (i.e., multiple myeloma and its variants) and/or because the MC produces organ damage (i.e., kidney failure, amyloidotic cardiomyopathy, etc.). The clinical laboratorian greatly contributes to the diagnosis and management of these conditions mainly through detection and quantitation of the monoclonal immunoglobulin, which represents an ideal tumor marker.

We give an overview of current methods for the detection of point mutations as well as small insertions and deletions in clinical diagnostics. For each method, the following characteristics are specified: (a) principle, (b) major modifications, (c) maximum fragment size that can be analyzed, (d) ratio and type of mutations that can be detected (e) minimum ratio of mutant to wild-type alleles at which mutations can be detected, and (j) detection methods. Special attention is paid to the possibilities of quality assessment and the potential for standardization and automation.

Phosphate is an important component of all tissues and disorders of phosphate homeostasis are common in hospital populations. Hypophosphatemia, which is much more frequent than hyperphosphatemia, is commonly caused by infusion of carbohydrate or respiratory alkalosis. If hypophosphatemia is prolonged, severe consequences such as hemolysis, myopathy, and respiratory dysfunction may occur. In order to prevent these complications it is important to measure plasma phosphate concentration in a number of clinical situations. If severe hypophosphatemia is detected, phosphate supplements should be given to correct it.