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Introduction The potential cross-contamination of additives between primary blood tubes is a well-known problem during sample collection. The aim of this study was to assess the impact of citrated blood contamination with different amounts of dipotassium ethylenediaminetetraacetic (K2 EDTA blood) on activated partial thromboplastin time ( APTT), prothrombin time ( PT), and fibrinogen. Methods Blood was collected from 15 ostensibly healthy volunteers into four 0.109 m citrate blood tubes followed by one K2 EDTA blood tube. The citrate tubes of each subject were pooled and divided in five aliquots. The whole blood of the K2 EDTA tube was then added in scalar amounts to autologous citrated blood aliquots, to obtain K2 EDTA contamination ranging from 0% to 43%, and thus mimic potential pre-analytical contamination. Results A statistically and clinically significant prolongation was observed for both APTT and PT between 29% and 43% K2 EDTA contamination, whereas the decrease of fibrinogen values became statistically and clinically significant at 43% K2 EDTA contamination. Conclusion The results of this investigation show that contamination of citrated blood with as much as 29% of K2 EDTA blood generates a significant bias in results of routine clotting assays. This has serious implications for patient safety and management. [ABSTRACT FROM AUTHOR]

Background:Tumour-released DNA in blood represents a promising biomarker for cancer detection. Although epigenetic alterations such as aberrant promoter methylation represent an appealing perspective, the discordance existing between frequencies of alterations found in DNA extracted from tumour tissue and cell-free DNA (cfDNA) has challenged their practical clinical application. With the aim to explain this bias of agreement, we investigated whether protocadherin 10 (PCDH10) promoter methylation in tissue was associated with methylation pattern in matched cfDNA isolated from plasma of patients with colorectal cancer (CRC), and whether the strength of concordance may depend on levels of cfDNA, integrity index, as well as on different clinical-pathological features.Methods:A quantitative methylation-specific PCR was used to analyse a selected CpG site in the PCDH10 promoter of 67 tumour tissues, paired normal mucosae, and matched plasma samples. The cfDNA integrity index and cfDNA concentration were assessed using a real-time PCR assay.Results:The PCDH10 promoter methylation was detected in 63 out of 67 (94.0%) surgically resected colorectal tumours and in 42 out of 67 (62.7%) plasma samples. The median methylation rate in tumour tissues and plasma samples was 43.5% (6.3-97.8%) and 5.9% (0-80.9%), respectively. There was a significant correlation between PCDH10 methylation in cfDNA and tumour tissue in patients with early CRC (P<0.0001). The ratio between plasma and tissue methylation rate increases with increasing cfDNA integrity index in early-stage cancers (P=0.0299) and with absolute cfDNA concentration in advanced cancers (P=0.0234).Conclusion:Our findings provide new insight into biological aspects modulating the concordance between tissues and plasma methylation profiles. [ABSTRACT FROM AUTHOR]

Objective. Although there is information on biochemical markers of muscle and cardiac damage following strenuous exercise, little is known about the kinetics of these markers in athletes performing sub-maximal exercise. Material and methods. Fifteen healthy, trained, Caucasian males took part in a 21-km run. Blood samples were collected before the run, immediately after (post), and 3 h, 6 h and 24 h thereafter. Biochemical markers of muscle and cardiac damage were evaluated on the Modular System, employing proprietary reagents. In no case did the concentration of troponin T increase by >0.03 ng/mL. The values of aspartate aminotransferase (AST), creatine kinase (CK), CK MB, lactate dehydrogenase (LDH) and myoglobin increased significantly immediately after the run and remained elevated 24 h thereafter. Results. The number of subjects with values above the upper limit of the relative reference ranges did not vary throughout the study period for AST and LDH, while it increased significantly for CK, CK MB and myoglobin. The major variation over the pre-run value was recorded for myoglobin (3-fold increment), whereas AST and LDH increased 1.1 and 1.3-fold, respectively. Conclusions. The results suggest the hypothesis that sub-maximal exercise influences the concentration of several biomarkers of muscle damage for up to 24 h with no biochemical signs of myocardial damage. [ABSTRACT FROM AUTHOR]

High-pressure liquid chromatography instruments specifically devised for separating haemoglobin (Hb) fractions have been increasingly employed by the hospital laboratories over the recent years since they allow easy and fast screening for several Hb variants. Although such instruments may be proposed as sensitive, specific and reliable alternatives to the classic electrophoretic techniques, a major drawback of this screening strategy is the almost identical retention time of several Hb variants. In particular, at least 18 Hb variants have been reported in the same retention window as HbA2, including HbE, the second most common β-chain variant in humans after sickle cell trait. Recently, we evaluated the performance characteristics of an improved buffer formulation originally conceived for Hb variants separation procedures on the fully automated high-pressure liquid chromatography instrument Tosoh G7. At variance with other fully automated high-pressure liquid chromatography analyzers, the elution pattern on the G7 in subjects heterozygous for HbE is characterized by the presence of four suggestive peaks (HbF, HbA, HbA2 and HbE), confirming the effective separation of HbE from HbA2. Because of its potential value in the diagnosis of the thalassaemia syndromes, the effective separation of HbA2 from HbE can provide clinical laboratories with a valuable information for the diagnostic reasoning. [ABSTRACT FROM AUTHOR]

Physical activity is essential for weight control, for limiting onset and complications of chronic disorders and for preventing impaired insulin sensitivity. Little is known about the glycaemic adaptations of physically active subjects, especially elite and professional athletes. Thus, we evaluated the glycaemic control in elite and professional cyclists by assessing fasting plasma glucose (FPG) and glycated haemoglobin (HbAlc). The study population consisted of 47 male professional road cyclists, 72 male elite road cyclists and 58 male sedentary blood donors. A significant difference was observed for FPG between sedentary controls (96 ± 8 mg/dL) and either elite (91 ± 8 mg/dL; p <0.001) or professional cyclists (89 ± 8 mg/dl; p <0.001). Athletes showed a consistent trend towards higher HbAl c values, reaching statistical significance between sedentary individuals and professional cyclists (5.2 ±0.3% versus 5.4 ± 0.2%; p = 0.017). In multiple linear regression analysis, the intensity of physical exercise is inversely correlated with FPG (r=-0.320; p<0.001) and directly correlated with HbAlc (r=0.190; p=0.006). These results demonstrate a significant association between intensity of the training regimen and both FPG and HbA1c, highlighting the need for establishing the appropriate critical difference for the measurement of FPG and HbA1c according to the training and exercise workload. [ABSTRACT FROM AUTHOR]

We evaluated the analytical performances of a new commercial chemiluminescent enzyme immunometric assay ford-dimer measurement on the Immulite 2000 automated analyser. The within- and between-run coefficients of variations for low, intermediate and highd-dimer concentrations ranged from 2.2% to 5.1% and from 2.9% to 6.0% respectively. The assay was proven linear in a range ofd-dimer concentrations comprised between 324 and 7602 ng/ml. Comparison of samples collected in either 0.109 mol/l sodium citrate or lithium–heparin tubes by Bland–Altman plots and nonparametric regression analysis ( y = 0.858 x − 39, r = 0.997; P < 0.0001) revealed a minimum bias, almost completely attributable to the dilution effect of the anticoagulant. Results of 56 outpatients’ citrated plasma samples analysed with the Immulite 2000d-dimer assay were compared with those of the current reference commercial immunoassay on the Mini Vidas Immunoanalyser. Although the nonparametric regression according to the method of Passing and Bablok and the relative Spearman's correlation coefficient was satisfactory (Immulite = 1.001 × Vidas − 181; r = 0.937, P < 0.001), some random discrepancies could be observed in Bland–Altman plots analysis. The analytical accuracy, calculated as the area under the Receiver Operating Characteristic (ROC) curve (AUC), was 0.961 ( P < 0.0001). On the basis of the results of the present evaluation, we conclude that the analytical performances and the main technical features of new Immulite 2000d-dimer assay make it a suitable method for the rapid quantification ofd-dimer in clinical laboratories. [ABSTRACT FROM AUTHOR]

The number of circulating newly produced platelets depends on the thrombopoietic capacity of bone marrow as well as platelet removal from the bloodstream. Flow cytometric analysis with thiazole orange (TO), a fluorescent dye that crosses platelet membranes and binds intracellular RNA, has been used to measure circulating reticulated platelets (RPs) with high RNA content as an index of platelet turnover. We first assessed the specificity of TO flow cytometry and then applied this method in the diagnosis of thrombocytopenia caused by impaired platelet production or increased destruction. We also explored the utility of TO flow cytometry to predict thrombocytopoiesis after chemotherapy-induced bone marrow aplasia. Venous blood, anticoagulated with K 2 EDTA, was incubated with 0.6&ThickSpace;µg/ml TO plus an anti-GPIIIa monoclonal antibody. The mean percentage of RPs in control subjects ( n &ThickSpace; = &ThickSpace;23) was 6.13&ThickSpace;±&ThickSpace;3.09%. RPs were 10.41&ThickSpace;±&ThickSpace;9.02% in patients ( n &ThickSpace; = &ThickSpace;10) with hematological malignancies during aplasia induced by chemotherapy and a significant increase in RPs (35.45&ThickSpace;±&ThickSpace;6.11%) was seen in the recovery phase. In 10 patients with idiopathic thrombocytopenic purpura, the percentage of TO positive platelets was 67.81&ThickSpace;±&ThickSpace;18.79 ( P &ThickSpace; [ABSTRACT FROM AUTHOR]

Chemical methods of measuring nitrogen in stools are complex, unpleasant, and therefore rarely performed. Recently, near infrared reflectance (NIRA) has been suggested for stool analysis. The aim of this study was to evaluate the possible application of this method in routine faecal nitrogen measurement. Nitrogen concentration and daily output were measured in the stools of 83 patients using NIRA and, for comparison, the Kjeldahl method. Nitrogen concentration and output ranged between 0.4-2.72 g% and 0.45-8.96 g/day respectively. Correlation coefficients (r), of 0.89 and 0.97 were found between the two methods for concentration and output respectively, and similar values were found in patients on enteral nutrition. Repeated measurements from the same stool collection, requiring only a few minutes, allowed homogenisation to be avoided. NIRA seems to be an easy, fast, and reliable alternative to chemical assays of nitrogen measurement in the management of patients with digestive disorders. [ABSTRACT FROM PUBLISHER]

This investigation was aimed at comparing a new method for measuring faecal fat excretion, carried out with a semi-automated instrument by using near infrared analysis (NIRA), with the traditional titrimetric (Van de Kamer) and gravimetric (Sobel) methods. Near infrared analysis faecal fat was assayed on the three day stool collection from 118 patients (68 chronic pancreatitis, 19 organic diseases of the gastrointestinal tract, 19 alcoholic liver disease, 12 functional gastrointestinal disorders). A strict linear correlation was found between NIRA and both the titrimetric (r = 0.928, p less than 0.0001) and the gravimetric (r = 0.971, p less than 0.0001) methods. On homogenised faeces, a mean coefficient of variation of 2.1 (SD 1.71)% was found. Before homogenisation (where a mean coefficient of variation of 7% was found) accurate results were obtained when the mean of five measurements was considered. In conclusion, the assay of faecal fat excretion by the near infrared reflessometry appears a simple, rapid and reliable method for measuring steatorrhoea. [ABSTRACT FROM PUBLISHER]

The Beijing Olympics will begin in August 2008 and athletes will face an unpredictable challenge. Based on present data, Beijing is one of the most polluted megacities in the world; the air concentrations of carbon monoxide (CO), ozone, nitrogen oxides (NO and NO2), sulphur dioxide (SO2) and particulate matter approach or exceed the current limits established by U.S. Environmental Protection Agency (EPA). Although the athletes who will be competing in Beijing are physiologically very different to the participants in most published studies, and it is therefore difficult to predict individual responses, there is little doubt that the presence of these air pollutants might be detrimental to athletic performance due to the marked increase (up to 20-fold) in ventilatory rate and concomitant nasal and oral breathing. Moreover, mouth breathing often bypasses the noise during strenuous exercise, increasing the deleterious effects of pollutants on health and athletic performance. Although limited, each decrement in athletic performance would have a potentially deleterious impact on top-class athletes competing in the next Olympics in China. Several Olympic records are regularly broken during the Olympics. Will this be the case for Beijing? [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Applicability of Estimated Glomerular Filtration Rate in Stratifying Chronic Kidney Disease," by Z. Khatami and colleagues in a previous issue

This article focuses on gene manipulation and improvement of athletic performances. Aerobic athletic performances are greatly improved by optimization of mechanisms of oxygen transport and delivery to peripheral tissues and muscles. There are both lawful and banned methods to achieve better muscular oxygenation; of these, the administration of erythropoiesis stimulating molecules, namely human recombinant erythropoietin or NESP, has been widely used by endurance athletes since the early 1990's. However, the introduction of a reliable laboratory test to detect blood doping with rHuEpo or derivatives has forced athletes to rely on alternative techniques, including blood and gene doping.