Sapporo City Research Articles

Citizen science reveals the present range and a potential native predator of the invasive slug Limax maximus Linnæus, 1758 in Hokkaido, Japan

The giant garden slug Limax maximus Linnaeus, 1758 (Limacidae, Pulmonata) is considered one of the most widely spread terrestrial molluscs in the world and is a formidable pest of agricultural and horticultural crops. This slug was recently introduced to Japan, where its population is now rapidly increasing and spreading. A naturalised population of L. maximus was first discovered in Hokkaido, Japan, in 2012 in the isolated natural forest of Maruyama Forest Park in Sapporo City, and the species has become common in this area. In the present study, we investigated observations of L. maximus reported by ordinary citizens acting as citizen scientists to assess the recent expansion of this invasive slug. We posted an announcement in the local newspaper requesting reports of the occurrence of L. maximus via e-mail and analysed 38 observations provided by local citizens. As a result of these reports, 16 naturalised populations of L. maximus were detected in Hokkaido, several of which were quite far from the original population in Sapporo City. Moreover, a terrestrial macrophagous leech, Orobdella kawakatsuorum Richardson, 1975 (Arhynchobdellida, Orobdellidae), is reported as a potential native predator of L. maximus for the first time.

Influencing Factors on the Increase of Child-rearing Households

Dealing with population decline and aging society is one the main challenges in Japan. The Japanese government aims to increase the quality of life of child-rearing households so as to ultimately increase birth rate and participation of females in the working market. Compact city policies and the Location Optimization Plan, recently proposed by the Government, are among the urban management measures adopted to support achieving this goal. Within this context, the purpose of the present research work is to investigate influencing factors on the increase of child-rearing households. Characteristics of child-rearing households in a local district of Sapporo city were explored, initially. Household micro data was estimated for the years of 1995 and 2010 by using Census data, Person Trip data as well as one available micro data simulation methodology. Analysis of the generated data showed that 25 of the total 90 Census zones presented an increase in the number of child-rearing households. Multiple Regression Analysis was then performed to explore the correlations between the increase in child-rearing households and factors related to building characteristics, land use types, and distance to urban facilities. Preliminary results suggest a negative correlation between the increase in child-rearing households and each of the building age, distance to elementary schools and commercial facilities. While it seems reasonable that newer buildings and shorter distances to schools (including nurseries) and supermarkets could help easing the daily activities of working parents, several other factors should be explored. The presented analysis can support government plans towards improving neighborhoods with a focus on child-rearing households, which in turn could help increase the birth rate and the number of two-worker households in Japan.

543P Thromboembolism in gastrointestinal tract cancer patients receiving chemotherapy: Preplanned analysis of risk factors and survival

Background We previously reported that incidence of thromboembolism (TEi) was 14% among Japanese gastrointestinal tract cancer (GTC) patients (pts) receiving chemotherapy (CTx), and multiple primary (MP), compared with single primary (SP), was suggested as a risk factor of TE (ASCO-GI 2016 Abst.541). This preplanned analysis was aimed to assess which status is significantly associated with high TEi; MP in a single organ (MPS) or MP in multiple organs (MPM), or both. Also, we aimed to explore the hypothesis that presence of TE is associated with negative prognosis in cancer pts. Methods All the patients received CTx for GTC in our institution from January 2008 to May 2015 were identified by reviewing electronic medical records. We extended the data cut-off date from 31 May 2015 to 30 November 2015, and updated the data of TEi. The associations between TE and MPS or MPM were analyzed using Chi-square test and Fisher's exact test. Kaplan-Meier analysis, Cox proportional hazards model, and log-rank test were used to assess the effect of TE on overall survival (OS). Results Five hundred thirteen Japanese GTC pts were analyzed in this retrospective study. Patient characteristics were as follows; female/male 197/316, median age 69.3 (range 21.1 - 89.1), gastric cancer (GC)/colorectal cancer (CRC) pts 213/300, MPS/ MPM/SP pts 25/29/461. Median follow-up period was 19 months. TEi was 15.4% (79/ 513) in total GTC pts, 32.0% (8/25) in MPS pts, 34.5% (10/29) in MPM pts, and 13.7% (63/461) in SP pts, respectively. Compared with SP pts, TEi was significantly higher in MPS (p = 0.019) and MPM (p = 0.005) pts, respectively. As for OS, there was no statistically significant difference between pts with and without TE (31 v33 months; HR,0.78;p=0.115). Conclusions We found that MPS and MPM were both associated with high TEi. Contrary to the previous reports from Western countries, no significant association was found between TE and poor survival in this analysis. Further prospective studies are required to assess the risk factors of TE and its impact on survival in Asian cancer pts. Clinical trial indentification UMIN000018912 Legal entity responsible for the study Michio Nakamura Funding Sapporo City General Hospital Disclosure M. Nakamura: Lecture fee from Daiichi Sankyo, Chugai Pharmaceutical Ltd. All other authors have declared no conflicts of interest.

Application of tritium in precipitation and baseflow in Japan: a case study of groundwater transit times and storage in Hokkaido watersheds

Abstract. In this study, we demonstrate the application of tritium in precipitation and baseflow to estimate groundwater transit times and storage volumes in Hokkaido, Japan. To establish the long-term history of tritium concentration in Japanese precipitation, we used tritium data from the global network of isotopes in precipitation and from local studies in Japan. The record developed for Tokyo area precipitation was scaled for Hokkaido using tritium values for precipitation based on wine grown at Hokkaido. Then, tritium concentrations measured with high accuracy in river water from Hokkaido, Japan, were compared to this scaled precipitation record and used to estimate groundwater mean transit times (MTTs). A total of 16 river water samples in Hokkaido were collected in June, July, and October 2014 at 12 locations with altitudes between 22 and 831 m above sea level and catchment areas between 14 and 377 km2. Measured tritium concentrations were between 4.07 (± 0.07) TU and 5.29 (± 0.09) TU in June, 5.06 (± 0.09) TU in July, and between 3.75 (± 0.07) TU and 4.85 (± 0.07) TU in October. We utilised TracerLPM (Jurgens et al., 2012) for MTT estimation and introduced a Visual Basic module to automatically simulate tritium concentrations and relative errors for selected ranges of MTTs, exponential–piston ratios, and scaling factors of tritium input. Using the exponential (70 %) piston flow (30 %) model (E70 %PM), we simulated unique MTTs for seven river samples collected in six Hokkaido headwater catchments because their low tritium concentrations were no longer ambiguous. These river catchments are clustered in similar hydrogeological settings of Quaternary lava as well as Tertiary propylite formations near Sapporo city. However, nine river samples from six other catchments produced up to three possible MTT values with E70 % PM due to the interference by the tritium from the atmospheric hydrogen bomb testing 5–6 decades ago. For these catchments, we show that tritium in Japanese groundwater will reach natural levels in a decade, when one tritium measurement will be sufficient to estimate a unique MTT. Using a series of tritium measurements over the next few years with 3-year intervals will enable us to estimate the correct MTT without ambiguity in this period. These unique MTTs will allow estimation of groundwater storage volumes for water resources management during droughts and improvement of numerical model simulations. For example, the groundwater storage ranges between 0.013 and 5.07 km3 with saturated water thickness from 0.2 and 24 m. In summary, we emphasise three important points from our findings: (1) one tritium measurement is already sufficient to estimate MTTs for some Japanese catchments, (2) the hydrogeological settings control the tritium transit times of subsurface groundwater storage during baseflow, and (3) in the future, one tritium measurement will be sufficient to estimate MTTs in most Japanese watersheds.

地方における他地区購買の実態と心理評価に関する研究

This study aims to determine the possible correlation between features of distant shopping and the impressions of distant shopping. The study used questionnaire surveys in three urban locations: one core city (the Chuo district in Sapporo city); and two satellite cities (Ishikari city and Kimobetsu town). The main conclusions of the study are as follows: (1) more than 80% of respondents in the three areas go shopping in Sapporo city at the weekend. (2) The significant features of distant shopping included: go shopping with other people, eat out, do other activities besides shopping, and long duration. These features were especially significant for respondents from Kimobetsu town. (3) Positive impressions of distant shopping on weekends are greater than on weekdays. (4) There is a correlation between features of distant shopping and positive impressions. (5) Younger people’s positive impressions are correlated with shopping with their families.

特許から見た地方食料品製造業の技術力と収益性

The Japanese food manufacturing industry has been expected to strengthen the country's industrial competitiveness and local economy revitalization. This article examines the technological capability and profitability of food manufacturing companies in Hokkaido, which is considered one of the most active food production areas in Japan. Financial information and one output from innovation activities, specifically patent information, have been utilized and analyzed. The analysis revealed four findings. First, very few strong relationships were seen between the sales amount and net profit to sales of Hokkaido food manufacturing companies. Many small and medium companies with high profitability were prevalent. Moreover, although food companies in the Tokachi district were smaller in size, they achieved higher profitability compared to food companies in Sapporo City. Second, food companies who possess patents showed higher profitability than those who do not possess patents. Third, food companies with high technological indicators such as the number of patent examinations and cited patents seemed to be capable of further increasing their business performances. Fourth, the technological capability of the whole region including Sapporo City and the Tokachi district showed an increasing trend in general. Although the Tokachi district still had a small number of patent applications, this area exhibited rapid improvement in its technological capability.

札幌市の園芸ボランティア支援制度「さっぽろタウンガーデナー」に登録する個人の実態

Nowadays, there are a number of citizens engaged in the community greenings by various kinds of flowers on an individual basis as well as on a group basis. In the case of Sapporo city, the municipal government supports both individuals and groups. In this study, we conducted the questionnaire survey with citizens, engaged in community greening in Sapporo city, to reveal the attitudes shown by two types of participants; one is on an individual basis and the other is both on an individual and a group basis. As a results, it appeared that there were some differences in the motivations between these two types of participants. More particularly, those engaged on an individual basis have much stronger motivations for “recreating themselves” and “growing flowers” than those engaged both on an individual and a group basis. On the other hand, both these two types of participants faced technical problems in horticultural areas. In addition, we found that about 60% of participants who engaged on an individual basis were willing to grow flowers in public spaces. In order to promote these activities more effectively, it is important to take advantage of coalitions across these two types of participants.

Etiology of Sudden Cardiac Arrest in Patients with Epilepsy: Experience of Tertiary Referral Hospital in Sapporo City, Japan

It has been reported that epilepsy patients had higher risk of sudden death than that of the general population. However, in Japan, there is very little literature on the observational research conducted on sudden fatal events in epilepsy. We performed a single-center, retrospective study on all the out-of-hospital cardiac arrest (OHCA) patients treated in our emergency department between 2007 and 2013. Among the OHCA patients, we extracted those with a history of epilepsy and then analyzed the characteristics of the fatal events and the background of epilepsy. From 1,823 OHCA patients, a total of 10 cases were enrolled in our study. The median age was 34 years at the time of the incident [9–52 years; interquartile range (IQR), 24–45]. We determined that half of our cases resulted from external causes of death such as drowning and suffocation and the other half were classified as sudden unexpected death in epilepsy (SUDEP). In addition, asphyxia was implicated as the cause in eight cases. Only the two near-drowning patients were immediately resuscitated, but the remaining eight patients died. The median age of first onset of epilepsy was 12 years (0.5–30; IQR, 3–21), and the median disease duration was 25 years (4–38; IQR, 6–32). Patients with active epilepsy accounted for half of our series and they were undergoing poly anti-epileptic drug therapy. The fatal events related to epilepsy tended to occur in the younger adult by external causes. An appropriate therapeutic intervention and a thorough observation were needed for its prevention.

Insights into the pathogenesis of multiple sclerosis: genetics and environment

It has been a great honor to host the second MS Summer College in Sapporo. For the past 13 years, clinicians and researchers involved in multiple sclerosis (MS) research have gathered to present their most recent findings and to engage in enthusiastic and informative discussions. Last year, the meeting was reconceived as the first MS Summer College, organized by Professor Kira, and building on the success of that first meeting, it is my great pleasure to welcome everyone to the second MS Summer College. I have confidence that we will continue to advance MS research while deepening our friendship at the same time. The theme of this second MS Summer College was “Insights into the pathogeneses of MS: genetics and environment.” The development of MS is influenced by interactions between multiple genetic and environmental factors. Historically, epidemiological studies have provided clues for the triggers of MS. These studies have identified latitude, or vitamin D as an important risk factor for MS. In addition, the observed link between infectious agents such as Epstein–Barr (EB) virus and MS has led to the “hygiene hypothesis” of MS development, which is further supported by recent advances in the field of mucosal immunology. At this meeting, Professor Goodin gave us an overview of the epidemiology of MS. In the following sessions, Professor Ohno and Dr. Okuno presented their current research on immune regulation by gut microflora, and Professor Fujiwara described recent progress made in the field of autoimmunity triggered by EB virus. In addition to epidemiological and immunological approaches, genetic studies using advanced technologies have identified several human leukocyte antigen (HLA) and non-HLA susceptibility loci involved in MS development. Continued advances in MS genetics lead to the elucidation of MS etiology and further aided in drug discovery and development. Professor Matsushita gave a comprehensive review of recent advances and perspectives in genetic studies on MS. As the effects of individual genes or even combinations of genes on MS development are relatively minor, they explain, at most, only half of the genetic risks for developing MS. Therefore, the limitations of these genetic studies based on “common disease–common variant hypothesis” have been pointed out. In this context, epigenetic mechanisms have been suggested as underlying MS pathogenesis and may partly explain the “missing heritability” of this complex disease. To discuss this in detail, Professor Iwamoto, following an overview of epigenetic studies on MS presented by Dr. Miyazaki, described the recent progress made in the epigenetics of psychiatric disorders, which is expected to provide insights into future research in MS epigenetics. We were also pleased to host Professor Nakashima, who gave a special clinical lecture on the recently identified anti-myelin oligodendrocyte glycoprotein (MOG) antibody-related disease, which has recently been identified among anti-AQP4 antibody-negative neuromyelitis optica and other demyelinating disorders. All these exciting and informative lectures were held in Sapporo, a young and vibrant city surrounded by beautiful nature and with abundant fresh food. I am firmly convinced that this issue of Clinical and Experimental Neuroimmunology (Supplemental Vol. 6) will provide you with the most recent progress in MS research and convey the stimulating atmosphere of the second MS Summer College. The author has no financial interests in the publication of the contents of this article or has no relationships with any company with such financial interests.

The exposure of the Croatian population to toxic environmental contaminants – “Dioxin-like” PCBs

We measured the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (PCBs), and non-dioxin-like PCBs in paired samples of blood and breast milk collected from 67 secundiparas in Sapporo City, Japan, and combined this data with those of the 30 secundiparas previously measured. The arithmetic mean total toxic equivalents (TEQ-WHO) concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in blood and breast milk of the 97 secundiparous subjects were 3.0–23 (mean: 13, median: 14) and 2.7–20 (mean: 8.6, median: 8.5) pg TEQ g−1 lipid, respectively. The sums of the concentrations of 56 non-dioxin-like PCB congeners that were measured in the subjects’ blood and breast milk were 16–326 (mean: 107, median: 100) and 12–252 (mean: 73, median: 67) ng g−1 lipid, respectively. The partitioning ratios of individual congeners of PCDDs, PCDFs, dioxin-like PCBs, and non-dioxin-like PCBs from blood to breast milk in secundiparas were almost the same as those of primiparas that have been recently reported, suggesting that the partitioning ratios of these compounds from maternal blood to breast milk in women is little affected by delivery. Furthermore, the partition of PCB congeners with chlorine at the 2-, 3-, 4′-, and 5-positions or the 2-, 4-, 4′-, and 5-positions of the biphenyl ring from the blood to the breast milk tended to occur at a higher level than that of other congeners. In particular, the levels of tetraCB-74 and hexaCB-146 in the breast milk for both primiparous and secundiparous mothers were slightly higher than those in the blood.

Analysis of urban growth and estimating population density using satellite images of nighttime lights and land-use and population data

We investigated the spatiotemporal dynamics of urban expansion in Japan from 1990 to 2006 by using gridded land-use data, population census data, and satellite images of nighttime lights. First, we mapped Defense Meteorological Satellite Program (DMSP) nighttime lights and land-use data onto the 1 km2 grid cell system of Japan to determine the proportional areas of DMSP and urban land use within each grid cell. Then, we investigated the relationships among population density, DMSP, and urban area. The urban/built-up area was strongly positively correlated with population density, and rapid expansion of the urban/built-up area around megacities was associated with population increases. In contrast, population density dropped steeply in rural areas and in small towns. Statistical analysis showed that correlation coefficients between population density and DMSP increased as the DMSP nighttime lights brightness value increased. We next estimated population density in the Hokkaido region using an ordinary least squares (OLS) regression model. Numerical evaluation of the results showed that the combination of land-use data and DMSP could be used to predict the population density. Finally, we compared OLS and geographically weighted regression (GWR) model for Sapporo city, Hokkaido. Compared with the OLS, the GWR can improve predictions of population density.

A Study on the application and practical use of the Urban Planning Proposal System in Sapporo City

A Study on the application and practical use of the Urban Planning Proposal System in Sapporo City

Importance of T1-MRI enhanced pyramidal tracts in differential diagnosis as to paraneoplastic encephalomyelitis

Department of Neurology, Hokkaido University Graduate School of Medicine, Sapporo, Japan Department of Neurology, Kushiro Rosai Hospital, Kushiro, Japan Department of Neurology, Brain Science Center, Sapporo City General Hospital, Sapporo, Japan Department of Clinical Research, Hokkaido Medical Center, Sapporo, Japan Department of Pathology, Kushiro Rosai Hospital, Kushiro, Japan Department of Neurology, Kanazawa Medical University, Uchinada, Japan

Changes in metamorphopsia in daily life after successful epiretinal membrane surgery and correlation with M-CHARTS score.

PurposeTo determine the correlation between the changes in metamorphopsia in daily life environment and the M-CHARTS scores after epiretinal membrane (ERM) removal, and to determine the criterion for determining whether clinically significant changes in the metamorphopsia score have occurred in M-CHARTS.MethodsWe studied 65 eyes undergoing vitrectomy for unilateral ERM. Self-administered questionnaires were used to examine the metamorphopsia in their daily life. The degree of metamorphopsia was determined by M-CHARTS. The receiver operating characteristic curve was used to determine the best predictor of the changes in metamorphopsia in daily life. To determine the reproducibility of the M-CHARTS score, another set of 56 eyes with ERM was tested twice on two different days.ResultsThe postoperative changes in the logarithm of the M-CHARTS score was defined as M2-value. The area under the receiver operating characteristic curve for the M2-value as a predictor of the changes in metamorphopsia in daily life was larger than area under the receiver operating characteristic curve obtained for any other parameter. The optimal cutoff value was −0.4. The 95% limits of agreement between test and retest measurements had a reproducibility of ±0.3 logarithm of the M-CHARTS score. Taking into account not only the reproducibility but also the consistency with the subjective changes, we determined the criterion for clinically significant changes in the M-CHARTS scores as a change of the M2-value by ≥0.4.ConclusionEvaluating the changes in the M-CHARTS scores in logarithmic form is favorable not only theoretically but also from the perspective of consistency with the subjective changes.

4種の拡散サンプラーを用いる札幌市における屋内外のガス状化学物質の実態調査

Gaseous chemical compounds such as carbonyls, volatile organic compounds (VOC), acid gases, basic gases, and ozone were measured in indoor and outdoor air of 40 houses throughout Sapporo city in the winter (January to March, 2012 and 2013) and summer (July to September, 2012) using four kinds of diffusive samplers. Almost all compounds in indoor air were present at higher levels in the summer than in the winter. The indoor concentrations of acetaldehyde and p-dichlorobenzene exceeded the Health, Labour and Welfare, Japan guideline in three and two houses, respectively. The mean concentrations of formaldehyde were 27 μg m−3 in the summer and 17 μg m−3 in the winter, and showed that the summer concentration was 1.6-fold higher than that in the winter. Nitrogen dioxide was present in extremely high concentrations in the winter, and it was suggested that the sources of nitrogen dioxide in indoor air are kerosene heaters, unvented gas stoves and heaters. Formic acid was generated by combustion because the nitrogen dioxide concentration in indoor air was well correlated with the formic acid concentration (correlation coefficient = 0.947). In outdoor air, the negative correlation between nitrogen dioxide and ozone was observed during the winter. It was suggested that the reaction of nitric oxide and ozone may influence the formation of nitrogen dioxide.

The situation and management of sika deer and brown bear in the urban area of Sapporo City

The situation and management of sika deer and brown bear in the urban area of Sapporo City

Extraction of urbanization at Sapporo City based on long-term meteorological observation data

Extraction of urbanization at Sapporo City based on long-term meteorological observation data

A Geographical Study of the Change in Urvan Development in Sapporo City

A Geographical Study of the Change in Urvan Development in Sapporo City

Synoptic climatology associated with extreme snowfall events in Sapporo city of northern Japan

AbstractSynoptic‐scale atmospheric circulations are crucial for extreme snowfall events. On the basis of topmost 100 snowfall intensity days in Sapporo, Hokkaido, Japan over winter seasons from 1992 to 2011, this study uses principal component analysis and K‐means clustering to characterize synoptic circulation patterns. Composite maps were constructed for sea‐level pressure, 850 hPa moisture and wind field, and 500 hPa geopotential height. The circulation patterns of the topmost seven snowfall events were triggered by the advection of very cold airmass from eastern Siberia, anomalously huge moisture with northerly strong wind, active and stationary Aleutian low, and 500 hPa deep cold‐core low over the southern Hokkaido.

Effectiveness of influenza vaccine in children in day‐care centers of Sapporo

We conducted a retrospective cohort study for evaluating the effectiveness of the trivalent inactivated influenza vaccine (TIV) among children aged 0-6 years in the 2011-2012 season in Sapporo City, Japan, because of scarce evidence. From 10 day-care centers in Sapporo City, Japan, 629 parents participated in the study. Each parent of the subjects described whether a subject received TIV once or twice in the 2011-2012 season, as well as the exact dates of receiving TIV from records in a maternal and child health handbook marked by a pediatrician. The incidence of influenza was defined as being affected with influenza as diagnosed by a pediatrician. Cox's proportional model was used for calculating a hazard ratio (HR) and its 95% confidence interval (95%CI) of TIV on an influenza incidence. After adjusting potential confounding variables, such as the day-care center, presence of comorbidity, size of household, number of siblings, and number of smokers in the home in addition to the age and sex of the child, HR was significantly reduced in the subjects aged 1 year (HR = 0.22, 95%CI 0.09-0.54) as well as in the total subjects (HR = 0.72, 95%CI 0.52-0.99). Consequently, the effectiveness of TIV was calculated as 78% for the subjects aged 1 year and 28% for the total subjects. Our study suggests that TIV is effective, especially in subjects aged 1 year. Further studies are necessary in different seasons, places, and populations to clarify the effectiveness of the influenza vaccine in children.