Study on Multicellular Systems Using a Phase Field Model

A model of multicellular systems with several types of cells is developed from the phase field model. The model is presented as a set of partial differential equations of the field variables, each of which expresses the shape of one cell. The dynamics of each cell is based on the criteria for minimizing the surface area and retaining a certain volume. The effects of cell adhesion and excluded volume are also taken into account. The proposed model can be used to find the position of the membrane and/or the cortex of each cell without the need to adopt extra variables. This model is suitable for numerical simulations of a system having a large number of cells. The two-dimensional results of cell adhesion, rearrangement of a cell cluster, and chemotaxis as well as the three-dimensional results of cell clusters on the substrate are presented.Comment: 13 pages, 7 figure

Association of paraoxonase 1 gene polymorphism with Intima-Media Thickness (IMT) of the carotid arteries in japanese type 2 diabetic patients

Purpose: We investigated the association between paraoxonase 1 (PON1)-192 genotypes and intimamedia thickness (IMT) of carotid arteries in diabetic patients. Methods: One hundred and fifty-five Japanese type 2 diabetic patients aged from 40 to 79 years were enrolled in this study. Genotypes of the patients were determined using the PCR-RFLP method. The IMT of carotid arteries of the subjects was measured by ultrasound imaging. Results: The PON1 genotypes frequencies were as follows: 18QQ (0.116), 70QR (0.452) and 67RR (0.432). IMT values of the RR group were significantly greater (1.08±0.41 mm, n=67) than those of the Q group, which consisted of patients carrying one or two Q alleles (0.95±0.27 mm, n=88, P=0.023). There were no significant difference in the clinical characteristics between the two groups. Conclusion: The results indicate that the PON1-192RR genotype is associated with intima media thickening of the carotid arteries in diabetic patients

Involvement of peripheral ionotropic glutamate receptors in orofacial thermal hyperalgesia in rats

<p>Abstract</p> <p>Background</p> <p>The purpose of the present study was to elucidate the mechanisms that may underlie the sensitization of trigeminal spinal subnucleus caudalis (Vc) and upper cervical spinal cord (C1-C2) neurons to heat or cold stimulation of the orofacial region following glutamate (Glu) injection.</p> <p>Results</p> <p>Glu application to the tongue or whisker pad skin caused an enhancement of head-withdrawal reflex and extracellular signal-regulated kinase (ERK) phosphorylation in Vc-C2 neurons. Head-withdrawal reflex and ERK phosphorylation were also enhanced following cold stimulation of the tongue but not whisker pad skin in Glu-injected rats, and the head-withdrawal reflex and ERK phosphorylation were enhanced following heat stimulation of the tongue or whisker pad skin. The enhanced head-withdrawal reflex and ERK phosphorylation after heat stimulation of the tongue or whisker pad skin, and those following cold stimulation of the tongue but not whisker pad skin were suppressed following ionotropic glutamate receptor antagonists administration into the tongue or whisker pad skin. Furthermore, intrathecal administration of MEK1/2 inhibitor PD98059 caused significant suppression of enhanced head-withdrawal reflex in Glu-injected rats, heat head-withdrawal reflex in the rats with Glu injection into the tongue or whisker pad skin and cold head-withdrawal reflex in the rats with Glu injection into the tongue.</p> <p>Conclusions</p> <p>The present findings suggest that peripheral Glu receptor mechanisms may contribute to cold hyperalgesia in the tongue but not in the facial skin, and also contribute to heat hyperalgesia in the tongue and facial skin, and that the mitogen-activated protein kinase cascade in Vc-C2 neurons may be involved in these Glu-evoked hyperalgesic effects.</p

Optimal waist circumference cut-off points and ability of different metabolic syndrome criteria for predicting diabetes in Japanese men and women: Japan Epidemiology Collaboration on Occupational Health Study

Abstract Background We sought to establish the optimal waist circumference (WC) cut-off point for predicting diabetes mellitus (DM) and to compare the predictive ability of the metabolic syndrome (MetS) criteria of the Joint Interim Statement (JIS) and the Japanese Committee of the Criteria for MetS (JCCMS) for DM in Japanese. Methods Participants of the Japan Epidemiology Collaboration on Occupational Health Study, who were aged 20–69 years and free of DM at baseline (n = 54,980), were followed-up for a maximum of 6 years. Time-dependent receiver operating characteristic analysis was used to determine the optimal cut-off points of WC for predicting DM. Time-dependent sensitivity, specificity, and positive and negative predictive values for the prediction of DM were compared between the JIS and JCCMS MetS criteria. Results During 234,926 person-years of follow-up, 3180 individuals developed DM. Receiver operating characteristic analysis suggested that the most suitable cut-off point of WC for predicting incident DM was 85 cm for men and 80 cm for women. MetS was associated with 3–4 times increased hazard for developing DM in men and 7–9 times in women. Of the MetS criteria tested, the JIS criteria using our proposed WC cut-off points (85 cm for men and 80 cm for women) had the highest sensitivity (54.5 % for men and 43.5 % for women) for predicting DM. The sensitivity and specificity of the JCCMS MetS criteria were ~37.7 and 98.9 %, respectively. Conclusion Data from the present large cohort of workers suggest that WC cut-offs of 85 cm for men and 80 cm for women may be appropriate for predicting DM for Japanese. The JIS criteria can detect more people who later develop DM than does the JCCMS criteria

Long-term trends in mortality risk associated with short-term exposure to air pollution in 10 Japanese cities between 1977 and 2015

Background and aim: Short-term associations between air pollution and mortality have been well reported in Japan, but the historical changes in mortality risk remain unknown. We examined temporal changes in the mortality risks associated with short-term exposure to four criteria air pollutants in selected Japanese cities.Methods: We collected daily mortality data for non-accidental causes (n = 5,748,206), cardiovascular (n = 1,938,743) and respiratory diseases (n = 777,266), and air pollutants (sulfur dioxide [SO2], nitrogen dioxide [NO2], suspended particulate matter [SPM], and oxidants [Ox]) in 10 cities from 1977 to 2015. We performed two-stage analysis with 5-year stratification to estimate the relative risk (RR) of mortality per 10-unit increase in the 2-day moving average of air pollutant concentrations. In the first stage, city-specific associations wereassessed using a quasi-Poisson generalized linear regression model. In the second stage, city-specific estimates were pooled using a random-effects meta-analysis. Linear trend and ratio of relative risks (RRR) were computed to examine temporal changes.Results: When stratifying the analysis by every 5 years, average concentrations in each sub-period decreased for SO2, NO2, and SPM (14.2–2.3 ppb, 29.4–17.5 ppb, 52.1–20.6 μg/m3, respectively) but increased for Ox (29.1–39.1 ppb) over the study period. We found evidence of a negative linear trend in the risk of cardiovascular mortality associated with SPM across sub-periods. However, the risks of non-accidental and respiratory mortality per 10-unit increase in SPM concentration were significantly higher in the most recent period than in the earliest period. Other gaseous pollutants did not show such temporal risk change. The risks posed by these pollutants were slightly to moderately heterogeneous in the different cities.Conclusions: The mortality risks associated with short-term exposure to SPM changed, with different trends by cause of death, in 10 cities over 39 years whereas the risks for other gaseous pollutants were relatively stable

Indices calculated by serum creatinine and cystatin C as predictors of liver damage, muscle strength and sarcopenia in liver disease

Serum creatinine (Cr)-based glomerular filtration rate (CrGFR) is overestimated in liver disease. The present study evaluated whether the difference in CrGFR and cystatin C (CysC) GFR (dGFR) is significant in liver disease. The Cr-to-CysC ratio and sarcopenia index (SI) have been reported to correlate with muscle volume. An estimated total body muscle mass with Cr, CysC and calculated body muscle mass (CBMM) has also been reported to correlate with muscle mass. The applicability of dGFR, SI and CBMM for liver disease were evaluated. A total of 313 patients with liver damage were evaluated for Child-Pugh score, albumin-bilirubin (ALBI) score, model for end-stage liver disease, fibrosis-4, Cr, CysC, Cr-based estimated GFR (CreGFR), CysCGFR and grip strength. Of the 313 patients, 199 were evaluated using cross-sectional computed tomography (CT) of the third lumbar vertebra to determine the skeletal muscle (SM) mass. dGFR, CBMM and SI were compared to liver damage, muscle strength and muscle mass. In the 313 patients, dGFR was correlated with age, ALBI and grip strength; CBMM was correlated with body mass index (BMI) and grip strength; and SI was correlated with BMI and grip strength. In patients evaluated with CT, the correlation coefficients for CBMM and SI with SM were 0.804 and 0.293, respectively. Thus, CBMM and SI were associated with sarcopenia. The relationship between dGFR and ALBI does not differ with different grades of CrGFR-based chronic kidney disease (CKD). dGFR is a marker of liver damage and muscle strength regardless of CKD. CBMM and SI are markers for sarcopenia in liver disease

Long-term trends in mortality risk associated with short-term exposure to air pollution in 10 Japanese cities between 1977 and 2015

Short-term associations between air pollution and mortality have been well reported in Japan, but the historical changes in mortality risk remain unknown. We examined temporal changes in the mortality risks associated with short-term exposure to four criteria air pollutants in selected Japanese cities.This work was supported by JSPS KAKENHI [grant numbers JP20H03942, JP19K10644] and the Nagasaki University WISE Program.Peer reviewe

Negative assimilation:how immigrants experience economic mobility in Japan

This paper examines the economic mobility of foreign migrants in Japan. In a country that is largely regarded as homogeneous and closed to outsiders, how and to what extent do immigrants achieve economic success? A survey conducted by the authors revealed that the conventional assimilationist perspective does not fully explain immigrants’ economic success in Japan. Migrants from the West experience what Chiswick and Miller (2011) refer to as “negative assimilation.” That is, their earnings decline over time in Japan. While negative assimilation was not clearly observed among immigrants from neighboring Asian countries, wages among them did not increase with the length of their stay in Japan. For both groups, the skills they brought from abroad were found to be largely accountable for their economic success, while locally specific human capital, such as education acquired in the host society, did not contribute to their earnings