[How to Apply Bayesian Theorem to the Evaluation of Myocardial Injury by Measuring High Sensitive Cardiac Troponins in the Patients with Suspected Acute Myocardial Infarction].

118 consecutive patients of suspected acute myocardial infarction with acute chest pain and shortness of breath visiting our emergency room were subjected for this clinical study. Based on final diagnosis of acute myocardial infarction (AMI) comprehensively determined by medical record, physical examination, ECG, echocardiography, cardiac catheterization, etc., except for cardiac biomarkers, the patients were classified into two groups, with AMI group (1) and without AMI group (0) and then ROC curve analysis was performed between without AMI group (1) and with AMI group (0). As a result of ROC curve analysis, AUC, cutoff value, sensitivity, specificity and likelihood ratio (LR) were calculated as shown in Fig. 4 (1-7) and Table 2 (1-7). Based on calculating equation led from Bayesian rules, post-test odds were calculated as product of pre-test odds and LR at the cutoff value in each biomarker such as hsCTnT, hsCTnI, h-FABP CK, CKMB activity and CKMB mass. As a result, post-test probability was improved from predictive pre-test probability 30% to post-test probability 89% and 86% in hsCTnT and hsTnI, respectively but less improved from 30% to 68% in h-FABP and unexpectedly improved from 30% to 82% in CKMB mass compared with hsCTnT and hsTnI. Based on Bayesian rule, it is very valuable to predict post-test probability from predictive pre-test probability 30% by calculation in particular, when post-test probability is over 85-90%. In conclusion, we believe that prediction of post-test probability by Bayesian rule can be surely used to evaluate clinical quality of biomarkers which are not depend on at least, specialty and experience of physicians.

Lymphocyte vitamin C levels as potential biomarker for progression of Parkinson's disease.

OBJECTIVES: Vitamin C is a major antioxidant and also is known as a neuromodulator in dopaminergic neurons. The aim of this study was to investigate the association between lymphocyte and plasma vitamin C levels in various stages of Parkinson's disease (PD). METHODS: Sixty-two individuals with PD (age 71 ± 8.8 y [mean ± SD]) being treated at Shizuoka General Hospital from December 2007 to August 2013 were consecutively recruited. PD severity was classified using the Hoehn-Yahr scale for staging PD. Fasting blood samples were collected, and plasma and lymphocyte vitamin C levels were measured. The association between PD severity and vitamin C levels was estimated by ordinal logistic regression with confounding variables. RESULTS: The distribution of Hoehn-Yahr stages in patients was as follows: stage I, 7; II, 28; III, 16; and IV, 11. Lymphocyte vitamin C levels in patients with severe PD were significantly lower (odds ratio [OR], 0.87; 95% confidence interval [CI], 0.80-0.97; P < 0.01) compared with those at less severe stages. Plasma vitamin C levels also tended to be lower in patients with severe PD; however, this was not significant (OR, 0.98; 95% CI, 0.96-1.00; P = 0.09). CONCLUSIONS: Our findings suggest that lymphocyte vitamin C levels in the peripheral blood may be a potentially useful biomarker for the progression of PD.

Visualization of sialidase activity in Mammalian tissues and cancer detection with a novel fluorescent sialidase substrate.

Sialidase removes sialic acid from sialoglycoconjugates and plays crucial roles in many physiological and pathological processes. Various human cancers express an abnormally high level of the plasma membrane-associated sialidase isoform.Visualization of sialidase activity in living mammalian tissues would be useful not only for understanding sialidase functions but also for cancer diagnosis. However, since enzyme activity of mammalian sialidase is remarkably weak compared with that of bacterial and viral sialidases, it has been difficult to detect sialidase activity in mammalian tissues. We synthesized a novel benzothiazolylphenol-based sialic acid derivative (BTP-Neu5Ac) as a fluorescent sialidase substrate. BTP-Neu5Ac can visualize sialidase activities sensitively and selectively in acute rat brain slices. Cancer cells implanted orthotopically in mouse colons and human colon cancers (stages T3-T4) were also clearly detected with BTP-Neu5Ac. The results suggest that BTP-Neu5Ac is useful for histochemical imaging of sialidase activities.