Determination of Docosahexaenoic Acid and n-3 Fatty Acids in Refined Fish Oils by H-NMR Spectroscopy: IUPAC Interlaboratory Study

A high-resolution proton nuclear magnetic resonance (NMR) method for determining the concentration (mg/g) of docosahexaenoic acid (DHA), the molar proportion (mol%) of DHA, and the molar proportion of total n-3 fatty acids in fish oils was validated by an IUPAC interlaboratory study (the Commission VI-6 on Oils, Fats, and Derivatives WG 3/98). Thirteen laboratories from 5 countries tested 6 pairs of blind duplicate fish oils: a refined tuna oil, 2 extracted tuna oils, an extracted bonito oil, an extracted salmon oil, and an extracted sardine oil ranging from 9 to 30 mol% DHA and from 20 to 35 mol% n-3 fatty acids. Before 1D-proton NMR measurements with 300–500 MHz instruments, oil samples were weighed and diluted with deuterochloroform solution containing ethylene glycol dimethyl ether as internal standard. To achieve precise performance, a detailed procedure for signal area measurement was described in the protocol, and all participants were instructed about the critical importance of following the protocol. Statistical performances with invalid and outlier data removed were as follows: repeatability relative standard deviations (RSDr) ranged from 0.91 to 2.62% and reproducibility relative standard deviation (RSDR) ranged from 1.73 to 4.27% for DHA concentration (mg/g); RSDr ranged from 0.39 to 2.06%, and RSDR ranged from 0.59 to 3.46% for mol% DHA; RSDr ranged from 0.23 to 0.90% and RSDR ranged from 0.85 to 2.01% for mol% total n-3 fatty acids. The method is expected to be recommended by IUPAC.

P6578Development of the novel program to diagnose atrial fibrillation using automated blood pressure monitor

Background

Atrial fibrillation (AF) is often asymptomatic and contributes to an increased risk of strokes. The development of proper screening device of AF is unmet medical needs worldwide. Recently, we had reported that multiple measurements using Omron automated blood pressure (BP) monitor with irregular heartbeat detection showed high sensitivity and specificity for AF detection in general cardiac patients, however, this method had limitations in discriminating between AF and other arrhythmias.

Purpose

The aim of this study is to develop a novel program that can accurately diagnose AF by discriminating it from other arrhythmias using the pressure pulse waveform data outputted from Omron automated BP monitor.

Methods

In our previous clinical research, BP measurements were performed 3 times each for 303 general cardiac patients (mean age: 72.2 years, 69.8% male) with recording the real-time single lead ECG, and a total of 909 pressure pulse waveforms were obtained. Among them, 840 pressure pulse waveforms from 280 patients (include 40 AF patients) used for further analysis. We developed a program to analyze and visualize uniquely the characteristics of AF waveform through the autocorrelation-based waveform processing system produced by Melody International Ltd, Kagawa, Japan. All visualized results were judged and classified into Sinus, Non-AF and AF by two individuals blinded to the results. For each patient who obtained 3 results, a two by two contingency table was created and sensitivity, specificity, and accuracy for diagnosing AF were calculated.

Results

Among 840 pressure pulse waveforms, only 21 (2 Sinus and 19 Non-AF) out of 720 Sinus and Non-AF waveforms were judged as AF, and 7 out of 120 AF waveforms were judged as Non-AF. None of AF waveforms was absolutely misjudged as Sinus. In analysis for each patient, when one or more AF judgements were found in 3 waveforms, the diagnosis of AF has sensitivity and specificity of 100% and 95.8%, respectively. When two or more AF judgements were found in 3 waveforms, the diagnosis of AF has sensitivity and specificity of 100% and 97.9%, respectively. In this rule, the diagnostic accuracy of AF reached up to 98.8%, and no sinus patients were misjudged as AF.

Conclusion

The novel program, which applied autocorrelation methods uniquely to analysis of the pressure pulse waveforms recorded by automated BP monitor, showed high sensitivity and high specificity for AF diagnosis in general cardiac patients. This program is expected to be useful for early diagnosis for asymptomatic AF patients.

Acknowledgement/Funding

The present research is supported by a grant through the SCOPE from the Ministry of Internal Affairs and Communications, Japan.

P13.01 TERTpromoter methylation is significantly associated withTERTupregulation and tumor progression in pituitary adenomas

BACKGROUND

Activation of telomerase plays a critical role in tumor development. Somatic alterations in the promoter of the telomerase reverse transcriptase (TERT) gene are a major mechanism of upregulating telomerase. Several mechanisms have been associated with TERT abnormalities, including TERT promoter mutations or methylation. Mutations in the TERT promoter have been observed in a subset of brain tumors, especially in adult gliomas. In pituitary adenomas (PAs), however, TERT abnormalities are not fully understood. The present study aimed to investigate not only mutational but also methylation status changes in the TERT promoter in PAs and to analyze their correlations with clinical variables.

MATERIAL AND METHODS

We retrospectively studied 70 PAs consisting of 53 primary and 17 recurrent samples. Clinical data, including age at surgery, sex, tumor size, tumor subtype, resection rate, presence or absence of postoperative irradiation, and progression-free survival (PFS), were obtained from medical records. First, we investigated TERT promoter hotspot mutations via Sanger sequencing. Next, we quantified the methylation status of the TERT promoter using methylation-sensitive high-resolution melting analysis (MS-HRM). Finally, we investigated TERT mRNA expression levels using real-time quantitative PCR. Fisher’s exact test was applied to evaluate the statistical significance between TERT promoter methylation status and tumor recurrence. PFS was calculated using Kaplan-Meier estimates and compared between methylated with ummethylated PAs with the log-rank test. The correlation between TERT promoter methylation status and mRNA levels was analyzed with the Mann-Whitney U-test. PFS was analyzed using multivariate analysis with the Cox proportional hazards model and included the following variables: age, sex, tumor size, tumor subtype, resection rate, radiation therapy, and methylation status.

RESULTS

TERT promoter hotspot mutations were not observed in any PA sample. Nineteen percent of PAs exhibitedTERT promoter methylation, which was significantly predominant in recurrent PA samples. PFS was significantly shorter in the methylated cases than in the unmethylated cases. Higher TERT expression levels were correlated with methylation status.

CONCLUSION

We found that TERT promoter methylation upregulated TERT expression and was associated with shorter PFS in PAs. Our results suggest thatTERT promoter methylation may be a potential biomarker for predicting tumor recurrence in PAs.

Preterm birth is associated with higher prevalence of wheeze and asthma in a selected population of Japanese children aged three years

BACKGROUND

The present cross-sectional study investigated the associations between low birthweight (LBW), high birthweight, preterm birth (PTB), postterm birth, small for gestational age (SGA), and large for gestational age (LGA) and the prevalence of wheeze and asthma in Japanese children aged three years (age range, 33-54 months; mean age, 38.7 months).

METHODS

Study subjects were 6364 children. A questionnaire was used to collect all data. Wheeze and asthma were defined according to the criteria of the International Study of Asthma and Allergies in Childhood.

RESULTS

The prevalence values of wheeze and asthma were 19.5% and 7.7%, respectively. Of the 6364 subjects, 8.8% were classified as LBW (<2500g), 90.4% as normal birthweight, 0.8% as high birthweight (≥4000g), 4.8% as PTB (<37 weeks), 94.8% as term birth, 0.4% as postterm birth (≥42 weeks), 7.8% as SGA (<10th percentile), 82.5% as appropriate for gestational age, and 9.7% as LGA (>90th percentile). Compared with term birth, PTB was independently positively associated with wheeze and asthma: the adjusted ORs (95% CI) were 1.47 (1.11-1.92) and 1.52 (1.02-2.20), respectively. An independent positive association was shown between PTB and wheeze only in boys; the interaction between PTB and sex was significant. Such an interaction between PTB and sex was not seen for asthma. No evident associations were observed between LBW, high birthweight, postterm birth, SGA, or LGA and wheeze or asthma.

CONCLUSIONS

This is the first study in Japan to show that PTB, but not LBW or SGA, was significantly positively associated with childhood wheeze and asthma.

New precise measurements of muonium hyperfine structure at J-PARC MUSE

High precision measurements of the ground state hyperfine structure (HFS) of muonium is a stringent tool for testing bound-state quantum electrodynamics (QED) theory, determining fundamental constants of the muon magnetic moment and mass, and searches for new physics. Muonium is the most suitable system to test QED because both theoretical and experimental values can be precisely determined. Previous measurements were performed decades ago at LAMPF with uncertainties mostly dominated by statistical errors. At the J-PARC Muon Science Facility (MUSE), the MuSEUM collaboration is planning complementary measurements of muonium HFS both at zero and high magnetic field. The new high-intensity muon beam that will soon be available at H-Line will provide an opportunity to improve the precision of these measurements by one order of magnitude. An overview of the different aspects of these new muonium HFS measurements, the current status of the preparation for high-field measurements, and the latest results at zero field are presented.

Relationship between the length of the forefoot bones and performance in male sprinters

Although recent studies have reported that the forefoot bones are longer in sprinters than in non-sprinters, these reports included a relatively small number of subjects. Moreover, while computer simulation suggested that longer forefoot bones may contribute to higher sprint performance by enhancing plantar flexor moment during sprinting, the correlation between forefoot bone length and sprint performance in humans has not been confirmed in observational studies. Thus, using a relatively large sample, we compared the length of the forefoot bones between sprinters and non-sprinters. We also examined the relationship between forefoot bone length and performance in sprinters. The length of forefoot bones of the big and second toes in 36 well-trained male sprinters and 36 male non-sprinters was measured using magnetic resonance imaging. The length of forefoot bones in the big and second toes was significantly longer in sprinters than in non-sprinters. After dividing the sprinters into faster and slower groups according to their personal best time in the 100-m sprint, it was found that the forefoot bone length of the second toe, but not that of the big toe, was significantly longer in faster group than in slower group. Furthermore, the forefoot bone length of the second toe correlated significantly with the personal best time in the 100-m sprint. This study supported evidence that the forefoot bones are longer in sprinters than in non-sprinters. In addition, this is the first study to show that longer forefoot bones may be advantageous for achieving superior sprint performance in humans.