Publications by authors named "Syou Maki"

11 Publications

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Visualization of cross-resistance between antimicrobial agents by asymmetric multidimensional scaling.

J Clin Pharm Ther 2021 Nov 24. Epub 2021 Nov 24.

Faculty of Management and Information Sciences, Tama University, Tokyo, Japan.

What Is Known And Objective: In our previous studies, we developed a cross-resistance rate (CRR) correlation diagram (CRR diagram) that visually captures the magnitude of CRRs between antimicrobials using scatter plots. We used asymmetric multidimensional scaling (MDS) to transform cross-resistance similarities between antimicrobials into a 2-dimensional map and attempted to visually express them. We also explored the antibiograms of Pseudomonas aeruginosa before and after the transfer to newly built hospitals, and we determined by the CRR diagram that the CRRs among β-lactam antimicrobials other than carbapenems decreased substantially with the facility transfer. The present study tests whether the analysis of CRRs by asymmetric MDS can be used as new visual information that is easy for healthcare professionals to understand.

Method: We tested the impact of changes in the nosocomial environment due to institutional transfers on CRRs among antimicrobials in asymmetric MDS, as well as contrasted the asymmetric MDS map and CRR diagram.

Results And Discussion: In the asymmetric MDS map, antimicrobial groups with the same mechanism of action were displayed close together, and antimicrobial groups with different mechanisms of action were displayed separately. The asymmetric MDS map drawn solely for antimicrobials belonging to the group with the same mechanism of action showed similarities to the CRR diagram. Also, the distance of each antimicrobial to other antimicrobials shown in the asymmetric MDS map was negatively correlated with the CRRs for them against that antimicrobial.

What Is New And Conclusion: The asymmetric MDS map expresses the dissimilarity as distances between agents, and there are no meanings or units on the ordinate and abscissa axes of the output map. In contrast, the CRR diagram expresses the antimicrobials' resistance status as values, such as resistance rate and CRR. By analysing the CRRs in the asymmetric MDS, it is feasible to visually recognize cross-resistance similarities between antimicrobial groups as distances. The use of the asymmetric MDS combined with the CRR diagram allows us to visually understand the resistance and cross-resistance status of each antimicrobial agent as a 2-dimensional map, as well as to understand the trends and characteristics of the data by means of quantitative values.
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http://dx.doi.org/10.1111/jcpt.13564DOI Listing
November 2021

Monitoring antimicrobial cross-resistance with cross-resistance rate correlation diagrams: Changes in antibiotic susceptibility of Pseudomonas aeruginosa due to hospital relocation.

J Clin Pharm Ther 2021 Apr 28;46(2):395-407. Epub 2020 Oct 28.

Faculty of Pharmacy, Osaka Ohtani University, Tondabayashi-shi, Osaka, Japan.

What Is Known And Objective: Though most medical institutions calculate antimicrobial susceptibility and resistance rates of microbes isolated at their own facility as part of their efforts to promote the proper use of antibiotics, very few, if any, regularly monitor cross-resistance rates between antimicrobial agents. The authors have devised a tool in the form of a cross-resistance rate correlation diagram (CRR diagram) that allows easy identification of increases or decreases in, or changes in the pattern of, antimicrobial cross-resistance. The objective was to perform an analysis by CRR diagrams of the effect of relocation to a newly built facility on antimicrobial resistance and cross-resistance rates at a medical facility.

Methods: The Sakai City Medical Center relocated in July 2015 to a newly built facility located in a different primary medical care zone 3.5 km away. Based on the drug susceptibility test data compiled at the Sakai City Medical Center, resistance and cross-resistance rates of Pseudomonas aeruginosa before and after the relocation of the hospital facility were calculated, and the rates were assessed using CRR diagrams.

Results And Discussion: It was possible to confirm the effect of hospital relocation on antibiotic susceptibility of P aeruginosa in terms of changes in resistance and cross-resistance rates. The effect of the facility's relocation on cross-resistance rates was particularly notable with respect to β-lactam antibiotics: cross-resistance rates among β-lactams decreased substantially, represented as a large wedge-shaped change towards the origin on the CRR diagram. Rates of cross-resistance between classes of antibiotics with a different mechanism of antibiotic action changed little.

What Is New And Conclusion: Including cross-resistance rates in the routine monitoring of resistance and susceptibility rates practiced by a medical institution can provide a comprehensive insight into the dynamics of bacterial flora in the facility. CRR diagrams, which allow visualization of the status and changes in cross-resistance, not only provide a new perspective for clinicians, but they also contribute to the proper use of antibiotics and serve as a tool in the education of healthcare professionals and students about antibiotic resistance.
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http://dx.doi.org/10.1111/jcpt.13296DOI Listing
April 2021

Influence of analysis conditions for antimicrobial susceptibility test data on susceptibility rates.

PLoS One 2020 23;15(6):e0235059. Epub 2020 Jun 23.

Faculty of Pharmacy, Osaka Ohtani University, Tondabayashi-shi, Osaka, Japan.

Background: To support effective antibiotic selection in empirical treatments, infection control interventions, and antimicrobial resistance containment strategies, many medical institutions collect antimicrobial susceptibility test data conducted at their facilities to prepare cumulative antibiograms.

Aim: To evaluate how the setpoints of duplicate isolate removal period and data collection period affect the calculated susceptibility rates in antibiograms.

Methods: The Sakai City Medical Center is a regional core hospital for tertiary emergency medical care with 480 beds for general clinical care. In this study, all the Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae isolates collected at the Sakai City Medical Center Clinical Laboratory between July 2013 and December 2018 were subjected to antimicrobial susceptibility tests and the resulting data was analyzed.

Findings: The longer the duplicate isolate removal period, the fewer the isolates are available for every bacterial species. Differences in the length of the duplicate isolate removal period affected P. aeruginosa susceptibility rates to β-lactam antibiotics by up to 10.8%. The setpoint of the data collection period affected the antimicrobial susceptibility rates by up to 7.3%. We found that a significant change in susceptibility could be missed depending on the setting of the data collection period, in preparing antibiogram of β-lactam antibiotics for P. aeruginosa.

Conclusions: When referring to antibiograms, medical professionals involved in infectious disease treatment should be aware that the parameter values, such as the duplicate isolate removal period and the data collection period, affect P. aeruginosa susceptibility rates especially to β-lactam antibiotics. And antibiogram should be updated within the shortest time period that is practically possible, taking into account restrictions such as numbers of specimen.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0235059PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7310835PMC
September 2020

Effects of work schedule and period of exposure on changes in urinary chromium and nickel excretion among rotating shift workers in a stainless-steel plant.

Chronobiol Int 2019 10 1;36(10):1439-1446. Epub 2019 Aug 1.

National Institute of Occupational Safety and Health , Tama-ku, Kawasaki , Japan.

We investigated the association between the period of exposure and changes in urinary excretion of chromium and nickel among rotating shift workers in a stainless-steel plant. The study participants were composed of two groups: the workers who were occupationally exposed to metals ("exposed group") and those who were not occupationally exposed to metals ("unexposed group"). The exposed and unexposed groups consisted of 56 and 40 male rotating shift workers, respectively. Urine samples were collected immediately before and immediately after the day shift, evening shift, and night shift. Urinary chromium and nickel were measured using inductively coupled plasma mass spectrometry. To correct for variations in urine dilution, urinary metal concentrations were expressed as a ratio to urinary creatinine concentration. In the exposed group, post-shift urinary excretion of chromium was significantly higher than pre-shift excretion. However, although urinary chromium excretion clearly increased after the day and night shift [63% ( < .0001) and 87% ( < .0001), respectively], urinary chromium excretion after the evening shift was only slightly higher than that measured before the evening shift (8%, = .028). Similar patterns were found for urinary nickel excretion ( = .0001, 0.20, and 0.18 for the day, evening, and night shifts, respectively). Non-uniform urinary excretion of metals between the day shift, evening shift, and night shift were observed in the exposed group; specifically, urinary metal excretion increased only slightly during the evening shift. In the unexposed group, no significant increase or decrease was found in median urinary chromium or nickel excretion (= .63-0.87). Work shift-specific permissible exposure level would be necessary.
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http://dx.doi.org/10.1080/07420528.2019.1645159DOI Listing
October 2019

Magnetothermal Convection of Water with the Presence or Absence of a Magnetic Force Acting on the Susceptibility Gradient.

Authors:
Syou Maki

PLoS One 2016 8;11(9):e0160090. Epub 2016 Sep 8.

Laboratory of Molecular Chemistry, Faculty of Pharmacy, Osaka Ohtani University, 3-11-1, Nishikiori-kita, Tondabayashi City, Osaka Pref. 584-8540, Japan.

Heat transfer of magnetothermal convection with the presence or absence of the magnetic force acting on the susceptibility gradient (fsc) was examined by three-dimensional numerical computations. Thermal convection of water enclosed in a shallow cylindrical vessel (diameter over vessel height = 6.0) with the Rayleigh-Benard model was adopted as the model, under the conditions of Prandtl number 6.0 and Ra number 7000, respectively. The momentum equations of convection were nondimensionalized, which involved the term of fsc and the term of magnetic force acting on the magnetic field gradient (fb). All the computations resulted in axisymmetric steady rolls. The values of the averaged Nu, the averaged velocity components U, V, and W, and the isothermal distributions and flow patterns were almost completely the same, regardless of the presence or absence of the term of fsc. As a result, we found that the effect of fsc was extremely small, although much previous research emphasized the effect with paramagnetic solutions under an unsteady state. The magnitude of fsc depends not only on magnetic conditions (magnitudes of magnetic susceptibility and magnetic flux density), but also on the thermal properties of the solution (thermal conductivity, thermal diffusivity, and viscosity). Therefore the effect of fb becomes dominant on the magnetothermal convection. Active control over the density gradient with temperature will be required to advance heat transfer with the effect of fsc.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0160090PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5015909PMC
August 2017

Magnetic field effects on copper metal deposition from copper sulfate aqueous solution.

J Phys Chem B 2014 May 28;118(18):4889-94. Epub 2014 Apr 28.

Faculty of Pharmacy, Osaka Ohtani University , Tondabayashi 584-8540, Japan.

Effects of a magnetic field (≤0.5 T) on electroless copper metal deposition from the reaction of a copper sulfate aqueous solution and a zinc thin plate were examined in this study. In a zero field, a smooth copper thin film grew steadily on the plate. In a 0.38 T field, a smooth copper thin film deposited on a zinc plate within about 1 min. Then, it peeled off repeatedly from the plate. The yield of consumed copper ions increased about 2.1 times compared with that in a zero field. Mechanism of this magnetic field effect was discussed in terms of Lorentz force- and magnetic force-induced convection and local volta cell formation.
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http://dx.doi.org/10.1021/jp5015675DOI Listing
May 2014

Seasonal and inter-day variation in serum high-sensitivity C-reactive protein in Japanese male workers: a longitudinal study.

Ind Health 2012 15;50(1):60-3. Epub 2011 Dec 15.

National Institute of Occupational Safety and Health, Nagao, Tama-ku, Kawasaki, Japan.

Although seasonal variation in high-sensitivity C-reactive protein (hsCRP) has been studied cross-sectionally and longitudinally, the results to date have been mixed. Here, to test seasonal variation in this compound with regard to within-subject, inter-day variation, we conducted a longitudinal follow-up study with repeated measurements in Japanese workers with low hsCRP. Blood samples were obtained from four male indoor daytime workers, who were aged 32-57 and commuted to offices in Kawasaki City, on six days within 2-wk windows in February and October, 2008. Serum hsCRP was measured using ultrasensitive latex-enhanced immunonephelometry. Among the subjects with detectable levels of hsCRP, individual median serum hsCRP levels were 38-74% higher in October than in February (p=0.03). This study identified the presence of a seasonal variation in the serum hsCRP level of Japanese workers with low hsCRP levels.
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http://dx.doi.org/10.2486/indhealth.ms1288DOI Listing
June 2012

Association between night-shift work and serum 25-hydroxyvitamin D levels in Japanese male indoor workers: a cross-sectional study.

Ind Health 2011 1;49(5):658-62. Epub 2011 Aug 1.

National Institute of Occupational Safety and Health, Kawasaki, Japan.

Although low vitamin D status resulting from night work is a suspected cause of various health disorders, few studies have investigated the association between night-shift work and vitamin D status. Here, we examined serum 25-hydroxyvitamin D (25OHD) levels in 19 Japanese indoor workers, including night-shift workers, in blood samples collected at the annual medical checkup (late July) in a metal tool factory. Analyses were finally restricted to 14 male workers (33-59 yr) in 3 groups: fixed daytime work (n=6), and rotating shift work with (n=4) and without (n=4) night shifts. No significant differences in serum 25OHD levels were observed among the three groups (p=0.98, Kruskal-Wallis test). One to two participants in each group had 25OHD levels lower than the 20 ng/ml reference value for vitamin D deficiency even in summer. These results clearly indicate the need for large-scale studies to test the hypothesis that night-shift work is associated with lower 25OHD levels.
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http://dx.doi.org/10.2486/indhealth.ms1271DOI Listing
February 2012

Vitamin D deficiency and seasonal and inter-day variation in circulating 25-hydroxyvitamin D and parathyroid hormone levels in indoor daytime workers: a longitudinal study.

Ind Health 2011 21;49(4):475-81. Epub 2011 Jun 21.

National Institute of Occupational Safety and Health, 6–21–1 Nagao, Tama-ku, Kawasaki, Japan.

Seasonal variation in circulating 25-hydroxyvitamin D (25OHD) levels related to seasonal and inter-day fluctuation in sunlight ultraviolet irradiation, may lead to misjudgments concerning 25OHD status in individual workers around threshold levels. Here, to examine seasonal and inter-day variations in plasma 25OHD, we conducted a longitudinal study involving indoor daytime workers. Subjects were four male indoor daytime workers aged 32-57 yr working in Kawasaki City, Japan. Blood samples were obtained on six days within two two-week periods in February and October, 2008. Plasma 25OHD, serum intact parathyroid hormone (PTH) and 1α,25-dihydroxyvitamin D [1α,25(OH)(2)D] were measured. Individual monthly mean 25OHD levels were 16-56% higher in October than in February (p=0.03), while individual monthly mean intact PTH levels were 15-41% lower in October (p=0.09). No seasonal change was observed in 1α,25(OH)(2)D (p=0.62). Notably, nearly all measured 25OHD levels in February were lower than the reference value of 20 ng/ml. Our study identified the occurrence of seasonal variation in circulating 25OHD and intact PTH levels, even after accounting for inter-day variability, and hypovitaminosis D in wintertime in indoor daytime male workers in Japan. Due to this variability, single spot measurements of 25OHD may lead to misjudgment of workers' vitamin D status.
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http://dx.doi.org/10.2486/indhealth.ms1255DOI Listing
December 2011

[Analysis of organic solvent poisonings occurring in Japan from 1995 to 2006].

Sangyo Eiseigaku Zasshi 2011 14;53(3):87-100. Epub 2011 Mar 14.

National Institute of Occupational Safety and Health, Japan, Kawasaki, Kanagawa, Japan.

Objectives: Statistical analyses based on incidence rate were carried out for organic solvent poisonings occurring in Japan.

Methods: We used the published data of "Typical cases of occupational diseases" and "Current situation of occupational disease occurrence" in the "Industrial Hygiene Guidebook (Roudoueisei no Shiori)". The number of workers as a population of occupational solvent handlers was obtained from the Ministry of Health, Labour and Welfare, Japan.

Results: The annual incidences of solvent poisoning from 1995 to 2006, poisoning, death-by-poisoning, and secondary poisoning were 3.3-5.4, 0.0-0.83, and 0.0-0.34 cases/(100,000 solvent handlers × yr), respectively. Annual incidence classified by manufacturing, construction, and other services were 2.5, 52.0, and 6.1, respectively. Manufacturing showed a small increase from 1999 to 2003, and stopped increasing after 2004. Construction had a peak in 2000. Other services notably decreased from 14.4 in 1999 to 2.5 in 2006. The monthly distribution of the number of poisoning cases was prominent in January. Annual incidences of poisoning, death-by-poisoning, and secondary poisoning were 3.9, 0.5, 0.2 for toluene, 3.5, 0.5, 0.3 for xylene, and 16.4, 4.7, 2.3 for trichloroethylene, respectively.

Conclusion: The annual incidences classified by industry and solvents showed no change for manufacturing, whereas that for construction notably decreased from 88.6 in 2000 to 12.0 in 2006.
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http://dx.doi.org/10.1539/sangyoeisei.b10012DOI Listing
November 2011

Crystallization and preliminary X-ray crystallographic analysis of Ca2+-free primary Ca2+-sensor of Na+/Ca2+ exchanger.

Acta Crystallogr Sect F Struct Biol Cryst Commun 2008 Dec 28;64(Pt 12):1125-7. Epub 2008 Nov 28.

Department of Physical Chemistry, Osaka University of Pharmaceutical Sciences, Takatsuki, Osaka 569-1094, Japan.

The plasma-membrane Na(+)/Ca(2+) exchanger (NCX) regulates intracellular Ca(2+) levels in cardiac myocytes. Two Ca(2+)-binding domains (CBD1 and CBD2) exist in the large cytosolic loop of NCX. The binding of Ca(2+) to CBD1 results in conformational changes that stimulate exchange to exclude Ca(2+) ions, whereas CBD2 maintains the structure, suggesting that CBD1 is the primary Ca(2+)-sensor. In order to clarify the structural scaffold for the Ca(2+)-induced conformational transition of CBD1 at the atomic level, X-ray structural analysis of its Ca(2+)-free form was attempted; the structure of the Ca(2+)-bound form is already available. Recombinant CBD1 (NCX1 372-508) with a molecular weight of 16 kDa was crystallized by the sitting-drop vapour-diffusion method at 293 K. The crystals belonged to the hexagonal space group P6(2)22 or P6(4)22, with unit-cell parameters a = b = 56.99, c = 153.86 A, beta = 120 degrees , and contained one molecule per asymmetric unit (V(M) = 2.25 A(3) Da(-1)) with a solvent content of about 55% (V(S) = 45.57%). Diffraction data were collected within the resolution range 27.72-3.00 A using an R-AXIS detector and gave a data set with an overall R(merge) of 10.8% and a completeness of 92.8%.
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http://dx.doi.org/10.1107/S1744309108032934DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2593703PMC
December 2008
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