Development of internal standard for lipoprotein subclass analysis using dual detection gel-permeation high-performance liquid chromatography system.

The LipoSEARCH® System is an innovative lipoprotein class analysis method based on gel-permeation high-performance liquid chromatography (HPLC). This system uses a gel permeation column to separate the major lipoprotein subclasses (chylomicron, very low-density lipoprotein, low-density lipoprotein, and high-density lipoprotein) in serum according to particle size and splits them into two pathways to measure total cholesterol (TC; esterified + unesterified cholesterol) and triglyceride (TG) concentrations simultaneously to obtain chromatograms for each. These chromatograms were analyzed based on the results of the calibration serum by fitting Gaussian curves to profile the 20 lipoprotein subclasses defined in detail. An important assumption of this HPLC system is its simultaneous detection of two pathways to guarantee the accuracy of each analysis. Therefore, in the present study, we investigated the development of an internal standard that can guarantee the simultaneous detection of this system by adding a pigment to the serum. We focused on quinone pigments with absorption at 550 nm, which is the wavelength used for the enzymatic assay of TC and TG concentrations in the system. As a result, we succeeded in producing overlapping pigment peaks that appeared after the analytical chromatograms in two pathways. It is also suggested that the pigment solution as an internal standard is stable in freezing storage and has little effect on the analysis. The developed internal standard is expected to contribute to the accuracy assurance of lipoprotein analysis by this dual-detection HPLC system.

Expert Consensus Document: Diagnosis for Chronic Constipation with Faecal Retention in the Rectum Using Ultrasonography.

Chronic constipation is a common gastrointestinal disorder in older adults, and it is very important to manage chronic constipation. However, evaluating these subjective symptoms is extremely difficult in cases where patients are unable to express their symptoms because of a cognitive or physical impairment. Hence, it is necessary to observe the patient's colonic faecal retention using objective methods. Ultrasonography observation for colonic faecal retention is useful for diagnosing constipation and evaluating the effectiveness of treatment. Since there was no standard protocol for interpreting rectal ultrasonography findings, we developed an observation protocol through an expert consensus. We convened a group of experts in the diagnosis and evaluation of chronic constipation and ultrasonography to discuss and review the current literature on this matter. Together, they composed a succinct, evidence-based observation protocol for rectal faecal retention using ultrasonography. We created an observation protocol to enhance the quality and accuracy of diagnosis of chronic constipation, especially rectal constipation. This consensus statement is intended to serve as a guide for physicians, laboratory technicians and nurses who do not specialise in ultrasound or the diagnosis of chronic constipation.

A novel sphingomyelin/cholesterol domain-specific probe reveals the dynamics of the membrane domains during virus release and in Niemann-Pick type C.

We identified a novel, nontoxic mushroom protein that specifically binds to a complex of sphingomyelin (SM), a major sphingolipid in mammalian cells, and cholesterol (Chol). The purified protein, termed nakanori, labeled cell surface domains in an SM- and Chol-dependent manner and decorated specific lipid domains that colocalized with inner leaflet small GTPase H-Ras, but not K-Ras. The use of nakanori as a lipid-domain-specific probe revealed altered distribution and dynamics of SM/Chol on the cell surface of Niemann-Pick type C fibroblasts, possibly explaining some of the disease phenotype. In addition, that nakanori treatment of epithelial cells after influenza virus infection potently inhibited virus release demonstrates the therapeutic value of targeting specific lipid domains for anti-viral treatment.-Makino, A., Abe, M., Ishitsuka, R., Murate, M., Kishimoto, T., Sakai, S., Hullin-Matsuda, F., Shimada, Y., Inaba, T., Miyatake, H., Tanaka, H., Kurahashi, A., Pack, C.-G., Kasai, R. S., Kubo, S., Schieber, N. L., Dohmae, N., Tochio, N., Hagiwara, K., Sasaki, Y., Aida, Y., Fujimori, F., Kigawa, T., Nishibori, K., Parton, R. G., Kusumi, A., Sako, Y., Anderluh, G., Yamashita, M., Kobayashi, T., Greimel, P., Kobayashi, T. A novel sphingomyelin/cholesterol domain-specific probe reveals the dynamics of the membrane domains during virus release and in Niemann-Pick type C.

Association between very long chain fatty acids in the meibomian gland and dry eye resulting from n-3 fatty acid deficiency.

In our previously study, we reported lower tear volume in with an n-3 fatty acid deficient mice and that the docosahexaenoic acid and total n-3 fatty acid levels in these mice are significantly reduced in the meibomian gland, which secretes an oily tear product. Furthermore, we noted very long chain fatty acids (≥25 carbons) in the meibomian gland. To verify the detailed mechanism of the low tear volume in the n-3 fatty acid-deficient mice, we identified the very long chain fatty acids in the meibomian gland, measured the fatty acid composition in the tear product. Very long chain fatty acids were found to exist as monoesters. In particular, very long chain fatty acids with 25-29 carbons existed for the most part as iso or anteiso branched-chain fatty acids. n-3 fatty acid deficiency was decreased the amount of meibum secretion from meibomian gland without change of fatty acid composition. These results suggest that the n-3 fatty acid deficiency causes the enhancement of evaporation of tear film by reducing oily tear secretion along with the decrease of meibomian gland function.

Effect of clarithromycin on steady-state digoxin concentrations.

OBJECTIVE: To evaluate the magnitude and dose-relatedness of the effect of clarithromycin on the pharmacokinetics of digoxin, and to compare the effects of clarithromycin with those of P-glycoprotein inhibitors. METHODS: Eight Japanese inpatients with congestive heart failure participated in this study. Each patient received oral digoxin therapy for at least 7 days and were coadministered oral clarithromycin to prevent or treat pneumonia. To evaluate the effects of clarithromycin on the pharmacokinetics of digoxin, digoxin concentrations were compared before and after coadministration of clarithromycin. RESULTS: Digoxin concentrations were higher after coadministration of clarithromycin in all patients (before, 0.838 +/- 0.329 ng/mL; after, 1.36 +/- 0.619 ng/mL); (p < 0.005). A significant correlation was observed between the dose of clarithromycin and the percentage of increase in the digoxin concentration. CONCLUSIONS: Digoxin concentrations increased during concomitant administration of clarithromycin, and this effect was dose-dependent on clarithromycin. The percentage increase in digoxin concentrations after the usual oral dose of clarithromycin (400 mg/d) is approximately 70%. Therefore, digoxin concentrations must be monitored carefully after coadministration of clarithromycin, and the doses of digoxin may need readjustment in patients who are concomitantly receiving clarithromycin.