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A preliminary study on humic-like substances in particulate matter in Malaysia influenced by Indonesian peatland fires

Fujii Y, Tohno S, Ikeda K, Mahmud M, Takenaka N

Sci Total Environ, 2021 Jan 20;753:142009.
PMID: 32890879 DOI: 10.1016/j.scitotenv.2020.142009

In this paper, ambient total suspended particulates (TSP) with a focus on humic-like substances (HULIS) are characterized based on intensive ground-based field samplings collected in Malaysia during non-haze and haze periods caused by peatland fires on the Indonesian island of Sumatra. Furthermore, concentrations of water-soluble organic carbon (WSOC) and carbon content of HULIS (HULIS-C) were determined, and fluorescence spectra of the HULIS samples were recorded by excitation emission matrix (EEM) fluorescence spectroscopy. The concentrations of WSOC and HULIS-C over the entire period ranged from 4.1 to 24 and 1.3 to 18 μgC m-3, respectively. The concentrations of WSOC and HULIS-C during the peatland fire-induced strong haze periods were over 4.3 and 6.1 times higher, respectively, than the average values recorded during the non-haze periods. Even during the light haze periods, the concentrations of WSOC and HULIS-C were significantly higher than their averages during the non-haze periods. These results indicate that peatland fires induce high concentrations of WSOC, particularly HULIS-C, in ambient TSP at receptor sites. EEM fluorescence spectra identified fulvic-like fluorophores at the highest intensity level in the EEM fluorescence spectra of the haze samples. A peak at excitation/emission (Ex/Em) ≈ (290-330)/(375-425) nm is also observed at high intensity, though this peak is normally associated with marine humic-like fluorophores. It is shown that a peak at Ex/Em ≈ (290-330)/(375-425) nm is not derived from marine sources only; furthermore, peatland fires are shown to be important contributors to HULIS around this peak.
Global metabolic network reorganization by adaptive mutations allows fast growth of Escherichia coli on glycerol

Cheng KK, Lee BS, Masuda T, Ito T, Ikeda K, Hirayama A, et al.

Nat Commun, 2014;5:3233.
PMID: 24481126 DOI: 10.1038/ncomms4233

Comparative whole-genome sequencing enables the identification of specific mutations during adaptation of bacteria to new environments and allelic replacement can establish their causality. However, the mechanisms of action are hard to decipher and little has been achieved for epistatic mutations, especially at the metabolic level. Here we show that a strain of Escherichia coli carrying mutations in the rpoC and glpK genes, derived from adaptation in glycerol, uses two distinct metabolic strategies to gain growth advantage. A 27-bp deletion in the rpoC gene first increases metabolic efficiency. Then, a point mutation in the glpK gene promotes growth by improving glycerol utilization but results in increased carbon wasting as overflow metabolism. In a strain carrying both mutations, these contrasting carbon/energy saving and wasting mechanisms work together to give an 89% increase in growth rate. This study provides insight into metabolic reprogramming during adaptive laboratory evolution for fast cellular growth.
Fulltext Generation of the induced pluripotent stem cell (hiPSC) line (JUFMDOi004-A) from a patient with hearing loss carrying GJB2 (p.V37I) mutation

Fukunaga I, Shiga T, Chen C, Oe Y, Danzaki K, Ohta S, et al.

Stem Cell Res, 2020 03;43:101674.
PMID: 31926383 DOI: 10.1016/j.scr.2019.101674

The gap junction beta-2 (GJB2) gene is the most common genetic cause of hereditary deafness worldwide. Especially, V37I mutation in GJB2 is most prevalent in Southeast Asia including Thailand, Malaysia, and Indonesia. Furthermore, it is the second most prevalent cause in Japan and China, and exhibits an audiometric phenotype of mild-to-moderate hearing loss. In this study, we generated induced pluripotent stem cells (iPSC) from peripheral blood mononuclear cells (PBMCs) of patient with homozygous V37I mutation. This iPSC line will be a powerful tool for investigating the pathogenesis and for developing a treatment for GJB2-related hearing loss.
Validation of virtual fractional flow reserve pullback curves

Seki R, Collison D, Ikeda K, Sonck J, Munhoz D, Bertolone DT, et al.

Catheter Cardiovasc Interv, 2024 Sep 29.
PMID: 39342486 DOI: 10.1002/ccd.31222

BACKGROUND: Angiography-derived fractional flow reserve (virtual FFR) has shown excellent diagnostic performance compared with wire-based FFR. However, virtual FFR pullback curves have not been validated yet.
OBJECTIVES: To validate the accuracy of virtual FFR pullback curves compared to wire-based FFR pullbacks and to assess their clinical utility using patient-reported outcomes.
METHODS: Pooled analysis of two prospective studies, including patients with hemodynamically significant (FFR ≤ 0.80) coronary artery disease (CAD). Virtual and wire-based FFR pullbacks were compared to assess the accuracy of virtual pullbacks to characterize CAD as focal or diffuse. Pullbacks were analyzed visually and quantitatively using the pullback pressure gradient (PPG). Patients underwent PCI, and the Seattle Angina Questionnaire (SAQ) was administered at 3-month follow-up.
RESULTS: A total of 298 patients (300 vessels) with both virtual and wire-based pullbacks who underwent PCI were included in the analysis. The mean age was 61.8 ± 8.8, and 15% were female. The agreement on the visual adjudication of the CAD pattern was fair (Cohen's Kappa: 0.31, 95% confidence interval: 0.18-0.45). The mean PPG were 0.65 ± 0.18 from virtual pullbacks and 0.65 ± 0.13 from wire-based pullbacks (r = 0.68, mean difference 0, limits of agreement -0.27 to 0.28). At follow-up, patients with high virtual PPG (>0.67) had higher SAQ angina frequency scores (i.e., less angina) than those with low virtual PPG (SAQ scores 92.0 ± 14.3 vs. 85.5 ± 23.1, p = 0.022).
CONCLUSION: Virtual FFR pullback curves showed moderate agreement with wire-based FFR pullbacks. Nonetheless, patients with focal disease based on virtual PPG reported greater improvement in angina after PCI.