Postexercise troponin I levels in patients with suspected stable ischemic heart disease.

BACKGROUND AND AIMS: Previous studies showed that troponin blood levels may increase after exercise. In this study, we assessed whether, among patients with suspected of having stable angina, the increase in troponin I (TnI) levels after exercise stress test (EST) might help identify those with obstructive coronary artery disease (CAD) and myocardial ischemia. METHODS: We performed maximal treadmill EST in 50 patients (age 64 ±â€Š9 years; 38 men) admitted to our Cardiology Department to undergo elective coronary angiography because of a suspicion of stable angina. TnI was measured before and 12 h after EST. RESULTS: TnI increased after EST compared with baseline in the whole population (from 0.44 ±â€Š0.76 to 0.84 ±â€Š1.12 ng/dl, P < 0.001). No difference in TnI increase was observed between patients with obstructive CAD (n = 29; 0.61 ±â€Š0.90-1.13 ±â€Š1.33 ng/dl) and no obstructive CAD (NO-CAD; n = 21; 0.21 ±â€Š0.46-0.44 ±â€Š0.54 ng/dl; P = 0.51). There was also no significant difference in post-EST TnI increase between patients with positive EST (n = 34; 0.56 ±â€Š0.89-1.05 ±â€Š1.28 ng/dl) or negative EST (n = 16; 0.19 ±â€Š0.26-0.39 ±â€Š0.43 ng/dl; P = 0.16). Moreover, no significant difference was observed in the post-EST TnI increase among groups of patients with positive EST and obstructive CAD, positive EST and NO-CAD, negative EST and obstructive CAD and negative EST and NO-CAD (P = 0.12). No clinical or EST variable was associated with post-EST TnI increase, although there was a tendency for a greater increase in those achieving a heart rate more than 85 vs. less than 85% of maximal predicted heart rate during EST (P = 0.075). CONCLUSION: TnI increase after EST in patients with suspected stable angina is largely independent of the results of coronary angiography and EST.

Post-exercise high-sensitivity troponin T levels in patients with suspected unstable angina.

BACKGROUND: Previous studies showed that troponin blood levels may increase after exercise. In this study we assessed whether, among patients admitted with suspected unstable angina, the increase in high-sensitive troponin T (hs-TnT) levels after exercise stress test (EST) might help identify those with obstructive coronary artery disease (CAD) and predict symptom recurrence during short term follow-up. METHODS: Maximal treadmill EST was performed in 69 consecutive patients admitted to the emergency room with a suspicion of unstable angina (acute chest pain but confirmed normal serum levels of cardiac troponins) was measured before and 4 hours after EST. Coronary angiography was performed in 22 patients (32.8%). RESULTS: hs-TnT increased after EST compared to baseline in the whole population (from 0.84±0.65 to 1.17±0.87 ng/dL, p<0.001). The increase was similar in patients with positive (n = 14) and negative (n = 55) EST (p = 0.72), and was also similar in patients with (n = 12) and without (n = 10) obstructive CAD at angiography (p = 0.91). The achievement of a heart rate at peak EST ≥85% of that predicted for age was the variable mainly associated with the post-EST hs-TnT increase at multivariable linear regression analysis (p = 0.005). The change after EST of hs-TnT did not predict the recurrence of symptoms or readmission for chest pain at 6-month follow-up. CONCLUSIONS: Our data show that hs-TnT increased after EST in patients with suspected unstable angina, which seemed largely independent of most clinical and laboratory variables. Thus, hs-TnT assessed after EST does not seem to be helpful to identify patients with obstructive CAD in this kind of patients.

Urinary Albumin Detection: Comparison of Two Different Methods.

BACKGROUND: Monitoring urinary albumin is a useful method in clinical practice for the management of diabetic nephropathy, chronic kidney disease, and hypertension. Currently there are neither standardized methods nor reference material for the determination of urinary albumin; for this reason it is useful to compare different assays used in clinical laboratory. OBJECTIVES: The aim of this study is to verify analytical performance of an immunoturbidimetric assay on Roche Cobas 8000 platform and to compare urinary albumin results with those obtained by immunonephelometry on Siemens Dade Behring BN II Nephelometer. RESULTS: The method comparison showed a good linear relationship, confirmed by Passing-Bablok and Bland-Altman plots. The turbidimetric assay meets the requirements of accuracy and precision for the practice of medical diagnostics and clinical use. CONCLUSIONS: The present study can contribute to the methods standardization and harmonization of urinary albumin assay.

Association Between Serum Ceruloplasmin Specific Activity and Risk of Alzheimer's Disease.

Meta-analyses demonstrate copper involvement in Alzheimer's disease (AD), and the systemic ceruloplasmin status in relation to copper is an emerging issue. To deepen this matter, we evaluated levels of ceruloplasmin concentration, ceruloplasmin activity, ceruloplasmin specific activity (eCp/iCp), copper, non-ceruloplasmin copper iron, transferrin, the ceruloplasmin/transferrin ratio, and the APOE genotype in a sample of 84 AD patients and 58 healthy volunteers. From the univariate logistic analyses we found that ceruloplasmin concentration, eCp/iCp, copper, transferrin, the ceruloplasmin/transferrin ratio, and the APOE genotype were significantly associated with the probability of AD. In the multivariable logistic regression analysis, we selected the best subset of biological predictors by the forward stepwise procedure. The analysis showed a decrease of the risk of having AD for eCp/iCp (p = 0.001) and an increase of this risk for non-ceruloplasmin copper (p = 0.008), age (p = 0.001), and APOE-ɛ4 allele (p <  0.001). The estimated model showed a good power in discriminating AD patients from healthy controls (area under curve: 88% ; sensitivity: 66% ; specificity 93%). These data strength the breakdown of copper homeostasis and propose eCp/iCp as a reliable marker of ceruloplasmin status.

Effects of 1,4-butanediol dimethacrylate and urethane dimethacrylate on HL-60 cell metabolism.

The polymerization of methacrylic monomers present in dental composite resins never reaches completion and therefore the leakage of residual monomers into the oral cavity and into biological fluids can cause local and systemic adverse effects. This work was carried out to study the in vitro biochemical interactions of urethane dimethacrylate and 1,4-butanediol dimethacrylate monomers with HL-60 cells, a cell line assumed as an experimental model for simulating granulocyte behaviour. Our main finding was that both monomers induce cell differentiation at toxic concentrations and that cytotoxicity seems to be caused by alterations of glucose metabolism arising from mitochondrial dysfunction rather than from oxidative stress, which could not be altogether verified under our experimental conditions. Our study could be considered as a useful approach to investigate the biochemical mechanisms that contribute to the cytotoxicity of methacrylate compounds and it underlines the importance of assessing such parameters for testing biocompatibility in order to promote the development of better and safer dental materials.

Description of a novel missense mutation of glucose-6-phosphate dehydrogenase gene associated with asymptomatic high enzyme deficiency.

We report a case of an asymptomatic young subject affected by severe deficiency of Glucose 6-phosphate dehydrogenase (G6PD) activity. A novel genetic mutation (G130A) in the third exon was found. We named this novel mutation the "G6PD RIGNANO variant". These findings may contribute to a better knowledge of molecular epidemiology of the G6PD mutation and may represent an additional variant to be studied for a deep comprehension of in vivo compensation mechanisms of G6PD deficiency.

Analytical evaluation of a new immunonephelometric method for homocysteine measurement.

BACKGROUND AND OBJECTIVES: Increased plasma homocysteine, a sulphur amino acid closely related to methionine metabolism, is considered an independent risk factor for cardiovascular diseases. Over the last years, the request to clinical laboratories for homocysteine measurement is constantly increased and, for this reason, several new methods have been developed, mainly with the aim of using them on completely automated instruments for routine analyses. In this paper, we evaluated a new immunonephelometric method for homocysteine determination on the Dade Behring BNII nephelometer. METHODS: Linearity, recovery, limit of detection (LOD) and total imprecision and were assessed; moreover, the method was compared with a HPLC reference method and with an automated immunoassay method (AxSYM Abbott). RESULTS: Recovery range was 96.4-104.2%, LOD was 0.5 micromol/L and total imprecision ranged from 5.0% to 7.6%. For the comparison study, the immunonephelometric method showed a good correlation both with HPLC (Y=1.02X-0.79, R(2)=0.99) and with the AxSYM method (Y=1.003X+0.06, R(2)=0.98). The Bland-Altman plot analysis shows that the immunonephelometric method has a slight positive bias with both HPLC (mean: 1.03 micromol/L, 95% confidence interval: 0.28-1.79 micromol/L) and AxSYM methods (mean: 0.45 micromol/L, 95% confidence interval: -0.03-0.94 micromol/L). CONCLUSION: The new nephelometric method from Dade Behring, for its analytical performance, can be easily considered a suitable method for homocysteine routine measurement; moreover, it cannot be ruled out that the widespread availability of nephelometers in clinical laboratories play a leading role in the choice of this method.