Clin Chem Lab Med
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Modern blood gas analyzers are often coupled to electrolyte and metabolite analyzers. We evaluated a Stat Profile Critical Care Xpress analyzer (STP CCX) for the rapid point-of-care measurement of blood gases (pH, pCO2, pO2, sO2), hematocrit (Hct), total hemoglobin (tHb), sodium (Na+), potassium (K+), chloride (Cl-), glucose (Glu), lactate (Lac), urea (BUN), ionized calcium (iCa) and ionized magnesium (iMg). ⋯ This analyzer is suitable as a simple and fast diagnostic tool in the laboratory and the critical care unit. However, users should be aware of biases that may lead to clinically significant errors in the assessment of acid-base status.
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Endothelial nitric oxide synthase (eNOS) produces nitric oxide, which plays a role in vasodilatation and in the regulation of cell growth and apoptosis. eNOS-deficient mice have impaired cardiac development resulting in congenital heart defects (CHDs). In humans, a single nucleotide polymorphism in the gene coding for eNOS (894G>T) is associated with birth defects. ⋯ Our data indicate that the eNOS 894G>T polymorphism is associated with increased CHD risk. The study also provides evidence of a possible gene-environment interaction effect on CHD risk between the maternal eNOS 894G>T variant and maternal cigarette smoking during pregnancy. This observation should be interpreted with caution because of the relatively small subgroups. Further study in a larger group of CHD subjects is required.
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Comparative Study
Holotranscobalamin in laboratory diagnosis of cobalamin deficiency compared to total cobalamin and methylmalonic acid.
Cobalamin-saturated transcobalamin, also called holotranscobalamin (holoTC), constitutes only between 6% and 20% of total plasma B(12). Serum concentration of holoTC is a new marker in laboratory diagnosis of cobalamin deficiency. We tested the utility of holoTC in assessing vitamin B(12) status. ⋯ Compared to total cobalamin, we observed a better performance of holoTC assay in detecting elevated concentrations of MMA in subjects with normal renal function. The majority of subjects with combined low holoTC and elevated MMA had normal concentrations of total cobalamin. HoloTC can be used as a first line parameter in detecting cobalamin deficiency.
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Pleural effusions are often classified into transudates and exudates based on Light's criteria. In this study, the diagnostic properties of Light's criteria were compared to those of several other analytes for the classification of pleural fluids into transudative and exudative. ⋯ Including effusion cholesterol, concentration in the routine biochemical work-up of pleural fluid allows for correct classification of more pleural effusions than achieved by use of Light's criteria. Combination of cholesterol and LDH had the highest discriminatory potential and the added advantage that no patient plasma is needed for correct classification.
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A large body of evidence attests that quality programs developed around the analytical phase of the total testing process would only produce limited improvements, since the large majority of errors encountered in clinical laboratories still prevails within extra-analytical areas of testing, especially in manually intensive preanalytical processes. Most preanalytical errors result from system flaws and insufficient audit of the operators involved in specimen collection and handling responsibilities, leading to an unacceptable number of unsuitable specimens due to misidentification, in vitro hemolysis, clotting, inappropriate volume, wrong container or contamination from infusive routes. Detection and management of unsuitable samples are necessary to overcome this variability. The present document, issued by the Italian Inter-society SIBioC-SIMeL-CISMEL (Society of Clinical Biochemistry and Clinical Molecular Biology-Italian Society of Laboratory Medicine-Italian Committee for Standardization of Hematological and Laboratory Methods) Study Group on Extra-analytical Variability, reviews the major causes of unsuitable specimens in clinical laboratories, providing consensus recommendations for detection and management.