Background: Total calcium is a less accurate test in predicting ionized calcium (Ca2+) in patients suspected of calcium metabolic disease. Nevertheless, total calcium continues to be used as routine measurement instead of adjusted Ca2+ (at pH 7.4). In the current study we evaluate a new multichannel instrument, the ISE Module E1200 for adjusted Ca2+ (at pH 7.4), containing three different ion-selective electrode (ISE) units. Methods: Serum from 1350 patients was compared to the ABL835 flex and KoneLab. Total calcium was also evaluated on the Dimension Vista 1500 system. Correlations between instruments were assessed by Deming regression and degree of agreement by Cohen's kappa (kappa). Results: Analytical imprecisions for the three ISE units for adjusted Ca2+ (at pH 7.4) was between 0.36% and 2.52%, and for pH between 0.32% and 3.24%. Results were comparable for each ISE unit (r = 0.797-0.917; all P <0.0001) and in high-throughput settings (r= 0.871; P <0.0001). The degree of agreement between instruments was moderate to good (kappa = 0.52-0.77). In contrast, there was a very poor agreement (kappa = -0.14) for total calcium with discrepancy in 53.4% of the samples. Conclusions: The new ISE Module E1200 is comparable with the ABL835 flex and KoneLab 30i and therefore may be used for routine analysis of serum adjusted Ca2+ (at pH 7.4). The measured adjusted Ca2+ (at pH 7.4) was less comparable with very poor agreement to total calcium measured on the Dimension Vista 1500 system.
Background: The European Society of Cardiology (ESC) guideline on non-ST-elevation acute coronary syndrome (N-STE ACS) proposed a new ACS rule-out protocol. Objectives: To evaluate this new tool, which uses diagnostic levels of high-sensitivity troponin T (hs-TnT; > 14 ng/L) in a slightly modified version and compare this to a recently proposed approach using undetectable levels of hs-TnT to rule out patients. Methods: There were 534 consecutive patients with suspected ACS included. Protocol 1: symptom duration, hs-TnT at 0 and 6-9 h, Global Registry of Acute Coronary Events (GRACE) score, and symptom status at 6-9 h. Protocol 2: a single blood sample of hs-TnT. The primary endpoint was a discharge diagnosis of ACS by blinded adjudication. Secondary endpoints were ACS re-admission < 30 days and 1-year mortality. Results: Protocol 1 classified 434/534 (81%) patients, with 27.9% being ruled out. All myocardial infarctions were correctly ruled in, but 15 cases of unstable angina were missed, resulting in a sensitivity and negative predictive value of 87.3% (79.6-92.5%) and 87.6% (80.4-92.9%), respectively. Protocol 2 ruled out 17.5% of the population, yielding a sensitivity and negative predictive value of 94.1% (88.2-97.6%) and 90.8% (81.9-96.2%), respectively. Both protocols correctly ruled in 2/3 patients with ACS re-admission < 30 days and 55/56 1-year fatalities. Conclusion: The present study confirms the diagnostic value of a modified version of the ESC rule-out protocol (Protocol 1) in N-STE ACS patients, but also suggests that a simpler protocol using undetectable levels of hs-TnT (Protocol 2) could provide a similar or even superior sensitivity. (C) 2015 Elsevier Inc.
Purpose: With the advent of high-sensitivity cardiac troponins (hscTn), detectable levels have become the norm and clinical challenge lies within distinction of normal and abnormal. We therefore sought to describe diagnostic and prognostic implications of the clinical introduction of hscTn. Methods: Myocardial infarction (MI) adjudication was based on hsTnT (Roche Diagnostics) and clinical setting. The 99% upper reference limit (URL) of 30 ng/L (10% CV) in the 4th generation TnT assay corresponds to 50 ng/L URL in the hsTnT assay. First, we used a 50 ng/L cut off (+dynamic changes) after the introduction of hsTnT in order to parallel MI diagnosis with the 4th generation assay. MI was then re-adjudicated by hsTnT levels >99% URL (>14 ng/L) with an absolute (abs.) change as rise/fall >50% of URL (>7 ng/L). We then compared hsTnT with a contemporary sensitivity TnI assay (sTnI) (Siemens Vista), with a 15 ng/L detection limit, a 45 ng/L 99% URL and significant abs. change of 20 ng/L. Results: In 335 chest pain patients with at least 2 values, 46 (13.7%) had MI by the 50 ng/l cut off. Re-adjudicating MI resulted in a 67% increase with 69 (20.6%) MI, 74% of the additional MI were type II. STnI only identified 51 of re-defined MI with modest 73.9% sensitivity (sens.) but high 95.9% specificity, yielding only 4.1% false positives, which was doubled (7.9%) with hsTnT. In 586 patients with at least 1 hsTnT value, 105 (17.9%) had undetectable levels (< 3 ng/L) at admission, ruling out all 1 year mortality [n = 81 (13.8%)] and all MI [n = 85 (14.5%)] with 100% sens. and NPV. 313 (53.4%) patients had hsTnT levels <14 ng/L, which predicted mortality with 96.3% sens. and 99% NPV, missing 3 events, and MI with 98.8% sens. and 99.7% NPV, missing 1 case. In 553 patients with at least 1 sTnI value, 376 (68%) had undetectable levels (< 15 ng/L) at admission, ruling out 1 year mortality [n = 73 (13.2%)] with 78.1% sens. and 95.7% NPV, missing 16 events. 430 (77.8%) had sTnI levels <45 ng/L, which predicted mortality with 58.9% sens. and 93% NPV, missing 30 events. MI at admission was ruled out with 86.7% sens. and 97.1% NPV by sTnI <15 ng/L, missing 11 cases, and with 75.9% sens. and 95.3% NPV by sTnI <45 ng/L, missing 20 cases. Conclusion: The advent of hscTn will substantially increase MI incidence, primarily type II. Fewer chest pain patients will have undetectable cTn but constitute a new very low risk population with absolute rule out of MI and 1 year all cause mortality. This implies higher rates of false positives with non-ischemic disease burden and diagnostic work up for MI is more important than ever.
With the advent of high-sensitive cardiac troponins (hscTn), ‘detectable’ levels have become the norm and will have to be differentiated from ‘elevated’ levels. Rising and falling levels differentiate acute from chronic myocardial injury, yet whether to use relative or absolute change or
Recent clinical trials show that adding copeptin or heart-type fatty acid-binding protein (H-FABP) to conventional cardiac troponins (cTn) assays improve diagnostic performances. Whether copeptin and H-FABP add information to high-sensitivity cTn (hscTn) is only sparsely investigated. We
We compare HER2 receptor amplification analysis by immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), and real-time polymerase chain reaction (real-time PCR) DNA copy-number assay following laser capture microdissection (LCM) in formalin-fixed paraffin embedded tissue from 40 women with verified ovarian cancer. We speculate that LCM should result in a more accurate assessment of HER2 amplification in our real-time PCR assay compared with IHC and FISH. HER2 overexpression measured by IHC, FISH, or real-time PCR was found in 5.0%, 5.0%, and 22.5%, respectively. HER2 negative results measured by IHC, FISH, or real-time PCR were found in 95%, 92.5%, and 60.0%, respectively. Analysis failed for IHC, FISH, or real-time PCR in 0%, 2.5%, or 17.5% of cases. Concordance between IHC and FISH, IHC and real-time PCR, or FISH and real-time PCR were 89.7%, 72.7%, or 78.1%, respectively. Only few ovarian cancer patients were HER2 overexpressed measured by IHC or FISH and thus could be eligible for antibody-based therapy with trastuzumab (Herceptin). Interestingly, we find an increased number of HER2 positive patients by real-time PCR analysis on microdissected cancer cells, suggesting a number of HER2 positive patients not detected by current methods. Thus, the concept of quantitative measurement of HER2 on microdissected cancer cells should be explored further.
We compare HER2 receptor amplification analysis by immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), and real-time polymerase chain reaction (real-time PCR) DNA copy-number assay following laser capture microdissection (LCM) in formalin-fixed paraffin embedded tissue from 40 women with verified ovarian cancer. We speculate that LCM should result in a more accurate assessment of HER2 amplification in our real-time PCR assay compared with IHC and FISH. HER2 overexpression measured by IHC, FISH, or real-time PCR was found in 5.0%, 5.0%, and 22.5%, respectively. HER2 negative results measured by IHC, FISH, or real-time PCR were found in 95%, 92.5%, and 60.0%, respectively. Analysis failed for IHC, FISH, or real-time PCR in 0%, 2.5%, or 17.5% of cases. Concordance between IHC and FISH, IHC and real-time PCR, or FISH and real-time PCR were 89.7%, 72.7%, or 78.1%, respectively. Only few ovarian cancer patients were HER2 overexpressed measured by IHC or FISH and thus could be eligible for antibody-based therapy with trastuzumab (Herceptin). Interestingly, we find an increased number of HER2 positive patients by real-time PCR analysis on microdissected cancer cells, suggesting a number of HER2 positive patients not detected by current methods. Thus, the concept of quantitative measurement of HER2 on microdissected cancer cells should be explored further.
Implementing a reform of postgraduate medical education in Denmark (2004), a pedagogical development function (PDF) which employs clinical associate professors (CAP) was established. To evaluate the impact of the PDF and the CAP, 1,355 questionnaires were mailed to physicians in eastern Denmark: 687 (51%) replied, 114 (17%) expressed knowledge of the PDF and 75 (11%) reported a personal contact to the PDF. The rather low knowledge of the PDF may be due to the CAPs' involvement in several educational functions at the same time which may impede identification of the ''true" efforts of the CAP/PDF.
Sunshine exposure increased the serum concentration of 25-hydroxyvitamin D (25-OHD) in 9 hemodialyzed patients. Mean 1,25-dihydroxyvitamin D (1,25-(OH)2D) was unchanged, but in two patients with low initial 25-OHD values this increase was accompanied by a rise in circulating 1,25-(OH)2D, although not to normal levels. One hemodialyzed patient developed liver insufficiency with a resultant reduction of serum 25-OHD concentration accompanied by a decrease in serum 1,25-(OH)2D concentration. The results indicate that the circulating levels of 1,25-(OH)2D in patients with end-stage renal failure are to some extent regulated by the serum 25-OHD concentrations. Injection of parathyroid hormone (PTH) induced minor increases in serum concentrations of 1,25-(OH)2D in patients with end-stage renal failure and even in anephric patients, suggesting the existence of an extrarenal PTH-sensitive 1-alpha-hydroxylase. However, the enzyme was stimulated by supraphysiological concentrations of PTH, and therefore not necessarily of importance in the normal regulation of calcium metabolism.
We present reference values for the excretion of cAMP in spot urine collected between 09.00 and 12.00 hours in 143 healthy children aged 2-200 months. The excretion of cAMP was creatinine-corrected and expressed as a substance concentration ratio (UcAMP/crea)U due to a positive significant correlation between the excretion of cAMP and creatinine (r = 0.68, p less than 0.001). The mean value (95% significance limits) for (UcAMP/crea)U was 748 mumol/mol (254-2206 mumol/mol). A logarithmic transformation of the ratio was used, since preliminary analysis showed uneven distribution; when the logarithmic transformation was used, the data appeared evenly distributed. There was no significant difference between the results for girls and boys. The value of lg(UcAMP/crea)U was related to the age or body surface area with decreasing values at higher age or body surface area. (r = -0.55 and r = -0.57, p less than 0.001). Spot urine for measurement of urinary cAMP instead of a 24 h collection appears preferable due to the practicability of the test in children.
A standardized protocol is described for the study of the calcium excretion in urine. After 12 h of fasting, urine is collected during 4 h with a water load of 10 ml per kg body weight. Urine is also collected during the following 20 h period on the habitual water and calcium intake. Reference values for 48 healthy adults are given as 0.25 and 0.75 quantiles. The measured activity of calcium ions (Ca2+) in urine is 0.09-0.27 mmol/kg for the 4 h period, 0.34 to 0.52 mmol/kg for the 20 h period; pH values are 5.61-6.43 (4 h) and 5.46 to 6.04 (20 h). The concentrations of total calcium are 0.67-2.05 mmol/l (4 h) and 3.16 to 4.94 mmol/l (20 h). The value for the excretion rate of calcium (standardized to a creatinine clearance of 100 ml/min) is 1.30-3.24 mumol/min for the 4 h period and 3.06-4.88 mumol/min for the 20 h period, with no significant difference between the results for men and women. The relationship between the Ca2+ activity and pH was studied in urine titrated with HC1 or NaOH. In all urine the Ca2+ activity falls with increasing pH in a typical biphasic manner. This indicates the need for simultaneous measurement of the pH in order to interpret data for the Ca2+ activity in urine.
INTRODUCTIONPrimary lactose malabsorption, adult type, is associated with the genotype CC in a lactase gene regulatory sequence (LCT-13910). In contrast, the genotype CT or TT in this position correlates with normal lactose absorption. Genotyping was implemented for routine testing of patients for primary lactose intolerance. We estimated the frequency of genotypes in a group of blood donors and compared it with the frequency among patients.MATERIALS AND METHODSIn total, 478 patients admitted to a hospital or to a specialist in gastroenterology and 100 blood donors were genotyped. DNA was obtained, and the relevant DNA sequence was amplified by real-time polymerase chain reaction (PCR) and analysed by the use of melting curve analysis.RESULTSAmong blood donors, the allelic distribution was 8% CC, 38% CT and 54% TT, whereas 14% CC, 37% CT, 48% TT was found in the patient group.CONCLUSIONCompared with the control group, the frequency of the CC genotype is almost doubled in the genotyped patients. Genotyping proved to be a convenient tool for routine clinical testing.
Measurement of serum-ionised magnesium has recently become available, and we report the first study of the relation of this parameter to arrhythmias, left ventricular function and mortality in patients with an acute myocardial infarction. Serum-ionised magnesium was determined in 217 consecutive patients admitted to hospital with an enzyme confirmed AMI. 70 healthy subjects acted as a control group. The main study parameters were occurrence of arrhythmias, left ventricular function estimated by echocardiography, and mortality after 10 months for the AMI patients. AMI patients had significantly lower serum-ionised magnesium compared to healthy controls but the level of serum-ionised magnesium in the acute phase of a MI was neither related to arrhythmias, left ventricular function nor mortality.
An ion-selective analyzer (NOVA 8 [previously NOVA CRT], NOVA Biomedical Waltham, USA) for simultaneous measurement of the concentration of ionized magnesium (cMG2+) and pH is investigated for linearity and influence of calcium ions on the Mg2+ results in different Mg2+ aqueous solutions with/without added calcium. Within the cMg2+ range 0-3.0 mmol/L, which covers most clinical values, we found cMg2+ values close to the line of identity, with a sensitivity about 94%, but 0.09 mmol/L lower in the absence of Ca2+. The analytical precision (CV) for human serum control was 1.7% in the physiological range. The accuracy and precision data for the Mg2+ electrode meet the demands for reliable results within the range for clinical use. We found a reference interval (95%) for cMg2+ of between 0.43 and 0.59 mmol/L serum, with a mean value of 0.51 mmol/L for healthy adults in the non-fasting state with no relation to sex or age. The mean cMg2+ was 61% of the mean concentration of plasma total magnesium (cTMg) ranging from (95%) 49% to 73%. No significant correlation was found between cMg2+ and total protein, albumin, phosphate, Ca2+, and total CO2. No significant difference was found between mean values for cMg2+ in whole blood, plasma, and serum. Serum samples could be stored for 24 h at 4 degrees C without significant change. Storage at -20 degrees C for 7 months caused a mean cMg2+ decrease of 8.3%. The mean slope delta lgcMg2+/delta pH measured after equilibration with different pCO2 values in each serum sample from the reference population was -0.0110, indicating a close agreement between the values for actual cMg2+ and adjusted cMg2+ (pH = 7.4).
BACKGROUND:Recent studies suggest that alternation in serum calcium influences the level of gallbladder bile ionized calcium (Ca2+). Theoretically, this could increase the risk of calcium precipitation in the gallbladder.METHODS:We therefore measured serum and gallbladder bile minerals in patients with gallstones (n = 27) and without (n = 10, controls). The serum samples were taken just prior to induction of anaesthesia and gallbladder bile was aspirated before any manipulation of the gallbladder.RESULTS:The active molality of Ca2+ in gallbladder bile was not statistically significant different between cases and controls (0.44 +/- 0.16 vs. 0.40 +/- 0.10 mmol/kg), whereas pH was significantly lower (6.94 +/- 0.31 vs. 7.36 +/- 0.28, p < 0.0001) and cholesterol higher (4.37 +/- 2.70 vs. 1.79 +/- 1.33 mmol/l; p < 0.01) in gallbladder bile obtained from cases. Serum Ca2+ at actual pH, magnesium and phosphate were significantly higher among cases than in controls. Gallbladder bile active molality of Ca2+ was significantly correlated with bile total calcium in both groups (r = 0.72; p < 0.001 and r = 0.91; p < 0.001, respectively). In controls only, we observed a positive relationship between serum Ca2+ at actual pH and the active molality of Ca2+ in bile (r = 0.61; p < 0.05).CONCLUSION:Our study demonstrates that Ca2+ in gallbladder bile does not differ between cases and controls. The lack of correlation between serum and gallbladder bile constituents in cases compared to controls suggests that changes in calcium equilibration between bile and serum in patients with gallstone disease might be of importance for the formation of gallstones.