Annals of clinical biochemistry
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Ann. Clin. Biochem. · Jul 2017
Elevated fasting and postprandial C-terminal telopeptide after Roux-en-Y gastric bypass.
Background Roux-en-Y gastric bypass increases circulating bile acid concentrations, known mediators of postprandial suppression of markers of bone resorption. Long-term data, however, indicate that Roux-en-Y gastric bypass confers an increased risk of bone loss on recipients. Methods Thirty-six obese individuals, median age 44 (26-64) with median body mass index at baseline of 42.5 (40.4-46) were studied before and 15 months after Roux-en-Y gastric bypass. ⋯ These changes occur in spite of improved vitamin D status with supplementation. These results suggest that post-Roux-en-Y gastric bypass increases in total bile acids do not effectively oppose an ongoing resorptive signal operative along the gut-bone axis. Serial measurement of C-terminal telopeptide may be of value as a risk marker for long-term skeletal pathology in patients post Roux-en-Y gastric bypass.
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Ann. Clin. Biochem. · May 2017
Stability of ionized calcium measurements at concentrations less than 0.3 mmol/L by point-of-care blood gas instruments: application for postfilter calcium quality control in patients with citrate anticoagulation during extracorporeal circulation.
Background Measurements of ionized calcium (Ca2+) at concentrations less than 0.3 mmol/L are required for postfilter control in patients who receive extracorporeal circulation with sodium citrate anticoagulation. This study evaluates the stability of the Ca2+ measurements at such concentrations. Methods The stability of the Ca2+ measurements was tested by measuring daily the external standard Qualicheck concentration 3 s7950, Radiometer (0.22-0.25 mmol/L) by blood gas instruments ABL800 and ABL90, Radiometer. ⋯ Conclusions For ABL800 instruments, it is necessary to use an extra quality control (<0.3 mmol/L) in addition to the usual quality controls to monitor Ca2+ measurements below 0.3 mmol/L. The acceptable stability of the Ca2+ measurements can be achieved by the Ca2+ membrane and sensor cassette replacement after four weeks. If the usual 12 weeks of Ca2+ membrane lifetime is maintained, it may result in a clinically significant overestimation of Ca2+ by ABL800 instruments.
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Ann. Clin. Biochem. · Mar 2017
Calprotectin is a potential prognostic marker for polycystic ovary syndrome.
Background Calprotectin is an antimicrobial, calcium and zinc-binding heterocomplex protein and has been proposed as a marker to rule out inflammatory conditions. The aim of this study was to evaluate the role of calprotectin in the diagnosis of polycystic ovary syndrome and to investigate the association between calprotectin and insulin resistance. Methods A total of 41 females with polycystic ovary syndrome and 54 age-matched without polycystic ovary syndrome were eligible for the study. ⋯ The optimum cut-off was 2.4 µg/mL with a 85.2% specificity and 75.6% sensitivity for polycystic ovary syndrome diagnosis. A significant positive correlation was found between the serum calprotectin and insulin resistance. Conclusions These results suggest that calprotectin might be a useful adjunct in the diagnosis of polycystic ovary syndrome, especially those with insulin resistance.
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Ann. Clin. Biochem. · Mar 2017
Hepatitis C virus core antigen assay: an alternative method for hepatitis C diagnosis.
Background The study aimed to evaluate a fully automated chemiluminescent immunoassay and compared it with a quantitative RNA assay and anti-HCV assay to verify the utility of this automated Ag assay as an alternative method for hepatitis C diagnosis. Methods A total of 229 serum samples previously tested for anti-HCV concentrations by the Architect Anti-HCV assay, were selected for HCV RNA testing by real time RT-PCR kit (Shanghai ZJ Bio-Tec Co., Ltd) and 125 specimens were tested for HCV Ag by the Architect HCV core Antigen kit. Results The log10 HCVAg and HCV RNA concentrations were highly correlated [ r = 0.834); with HCV RNA as the comparator test, HCVAg had 100% specificity, 100% positive predictive value (PPV) and 94.8% sensitivity. ⋯ Receiver operator characteristic curve analysis showed that the area under the curve of HCV core Ag (0.989) was greater than HCV Ab (0.871). HCV Ag concentrations and RNA-to-Ag ratio of the groups for HCV RNA concentrations ≤105 and >105 IU/mL were both significantly different from each other ( P < 0.05). Conclusion The Architect HCV core Ag assay may be an alternative method for hepatitis C diagnosis, performed on the same analytical platform and sample as the anti-HCV assay, shortening the diagnostic window period, demonstrating good correlation with HCV RNA assay with high specificity and positive predictive value.
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Anaemia is a condition in which the number of red cells necessary to meet the body's physiological requirements is insufficient. Iron deficiency anaemia and the anaemia of chronic disease are the two most common causes of anaemia worldwide;1 iron homeostasis plays a pivotal role in the pathogenesis of both diseases. An understanding of how iron studies can be used to distinguish between these diseases is therefore essential not only for diagnosis but also in guiding management. This review will primarily focus on iron deficiency anaemia and anaemia of chronic disease; however, iron overload in anaemia will also be briefly discussed.