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Plasma amino acids reflect the dynamics of amino acids in organs and their levels have clinical significance. Amino acids as clinical indicators have been evaluated as a mixture of d- and l-amino acids because d-enantiomers are believed to be physiologically nonexistent. However, it has become clear that some d-amino acids are synthesized by endogenous enzymes and symbiotic bacteria. Here, using a two-dimensional HPLC system, we measured enantiomers of all proteinogenic amino acids in plasma and urine and analyzed for correlation with other biochemical parameters in humans who underwent health checkups at our institutional hospital. Four d-amino acids (d-asparagine, d-alanine, d-serine, and d-proline) were detected in the plasma, amounting to less than 1% of the quantities of l-amino acids, but in the urine at several tens of percent, showing that d-amino acids have much higher fractional excretion than their L-counterparts. Detected plasma d-amino acids and d-/l-amino acid ratios were well correlated with renal parameters, such as blood urea nitrogen, creatinine, and cystatin C. On the other hand, a set of plasma l-amino acids were associated with body mass index and correlated with metabolic parameters such as liver enzymes, lipids, blood glucose, and uric acid. Thus, chiral resolution of plasma amino acids revealed totally different associations of the enantiomers with organ functions, and warrants further investigation for clinical and laboratory usefulness. [ABSTRACT FROM AUTHOR]

Rationale, aims, and objectives: The aim of this observational study is to identify factors by which some pancreatic cystic lesions (PCLs) were undetectable at transabdominal ultrasonography (TAUS), using magnetic resonance imaging (MRI) as reference standard. Methods: The database for 781 consecutive subjects who underwent a health checkup including fat computed tomography and upper abdominal MRI as option was searched. The presence of fatty liver and fatty pancreas was diagnosed by TAUS, and atrophic pancreas was determined by reevaluating the image of the pancreas in the chest computed tomography for screening. Subjects with PCL detected and those undetected at TAUS were statistically compared in clinical characteristics. Results: The prevalence of PCL detected at MRI was 17.8% in the general population. Multivariate logistic regression analysis showed that fatty liver, body mass index, and the size of PCL were significantly associated with the factors influencing the visualization of PCL at TAUS (odds ratio [OR]: 0.337, 95% confidence interval [CI]: 0.154‐0.734, P = 0.006; OR: 0.852, 95% CI: 0.737‐0.985, P = 0.030; OR:1.120, 95% CI: 1.045‐1.200, P =.001). Thirty‐six PCLs (64.3%) in a total of 56 PCLs were undermeasured by TAUS. Additionally, nine (56%) out of 16 PCLs (≥ 15 mm) were undermeasured by 5 mm or more by TAUS, although a significantly higher detection rate was observed for PCLs (≥ 15 mm) in comparison with that for PCLs (< 15 mm) (80% vs 33.6%, P =.000). Conclusions: It should be noted that coexisting fatty liver may lower the detection of PCL, and its size may be underestimated by TAUS. [ABSTRACT FROM AUTHOR]