Biomedical subjects

Keiko Nakamura

Publications and source records attributed to Keiko Nakamura.

9 recordsLinked to original sources

PubMed2003

Interplanetary dust from the explosive dispersal of hydrated asteroids by impacts.

The Earth accretes about 30,000 tons of dust particles per year, with sizes in the range of 20-400 microm (refs 1, 2). Those particles collected at the Earth's surface--termed micrometeorites--are similar in chemistry and mineralogy to hydrated, porous meteorites, but such meteorites comprise only 2.8% of recovered falls. This large difference in relative abundances has been attributed to 'filtering' by the Earth's atmosphere, that is, the porous meteorites are considered to be so friable that they do not survive the impact with the atmosphere. Here we report shock-recovery experiments on two porous meteorites, one of which is hydrated and the other is anhydrous. The application of shock to the hydrated meteorite reduces it to minute particles and explosive expansion results upon release of the pressure, through a much broader range of pressures than for the anhydrous meteorite. Our results indicate that hydrated asteroids will produce dust particles during collisions at a much higher rate than anhydrous asteroids, which explains the different relative abundances of the hydrated material in micrometeorites and meteorites: the abundances are established before contact with the Earth's atmosphere.

Journal Article↗

PubMed2003

Visual localisation of community health needs to rational decision-making in public health services.

The objectives were to visualise the locations of community health needs and to develop a community health needs assessment geographic information system (GIS) for rational decision-making in public health services. We compiled census data, digital data of basic planning maps, digital data of topographic maps, contents of registers of medical and welfare facilities, and statistics of establishments into a geographical database; visualised geographical distributions of specific community health needs by integrating sets of indicators to reflect individual needs; and quantified their clustering by the nearest neighbour method. The database aggregated 3400 items of demographic, life and environmental factors. Thematic maps and clustering values showed different patterns of geographical distribution of the individual community needs. Means to match needs with services in smaller geographical units were discussed. This GIS will support appropriate resource allocation, intersectoral collaboration and greater transparency in planning and implementing services, by visualising locations of community health needs.

Adolescent↗

PubMed2003

Rice gene expression in response to N-acetylchitooligosaccharide elicitor: comprehensive analysis by DNA microarray with randomly selected ESTs.

N-acetylchitooligosaccharides are potent elicitors to suspension-cultured rice cells, inducing a set of defense reactions. Expression of defense-related genes is considered to play an important role in defense reactions, and we employed microarray analysis of 8987 randomly selected expressed sequence tags to analyze the changes in gene expression caused by N-acetylchitooctaose. In this experiment, 166 genes were significantly induced and 93 genes were repressed. RNA gel blot analysis of 16 of these genes confirmed the microarray results. Of the 259 ESTs identified as responsive to N-acetylchytooctaose, 18 genes are related to signal transduction, including five calcium-dependent protein kinases (CDPKs). Among these, three novel CDPKs responsive to N-acetylchitooctaose were isolated.

Amino Acid Sequence↗

PubMed2003

Novel gene encoding a Ca2+-binding protein and under hexokinase-dependent sugar regulation.

A cDNA encoding a predicted 15-kDa protein was earlier isolated from sugar-induced genes in rice embryos (Oryza sativa L.) by cDNA microarray analysis. Here we report that this cDNA encodes a novel Ca2+-binding protein, named OsSUR1 (for Oryza sativa sugar-up-regulated-1). The recombinant OsSUR1 protein expressed in Escherichia coli had 45Ca2+-binding activity. Northern analysis showed that the OsSUR1 gene was expressed mainly in the internodes of mature plants and in embryos at an early stage of germination. Expression of the OsSUR1 gene was induced by sugars that could serve as substrates of hexokinase, but expression was not repressed by Ca2+ signaling inhibitors, calmodulin antagonists and inhibitors of protein kinase or protein phosphatase. These results suggested that Os-SUR1 gene expression was stimulated by a hexokinase-dependent pathway not mediated by Ca2+.

Amino Acid Motifs↗

PubMed2003

[Nursing measures against adverse reaction from anti-cancer chemotherapy].

Combination chemotherapy for leukemia develops bone marrow suppression. Infection or hemorrhage disorders the treatment, and may influence the clinical result. The caring staff must understand the pathology of bone marrow suppression. Visitors observe the hospital rules. Foods are also limited, city water and uncooked foods are prohibited. To keep oral cavity clean, pretreatment of some decayed teeth, and frequent gargling with sterilized water are needed. Defecation control is important. Sitz bath or shower toilet is helpful. Hand cleaning is essential for before a meal, after defecation and after a going out. Bathing is fundamental to cleaning body. No bathing is dirty. Medical catheters are checked up every day. Thrombocytopenia(< 30,000/microliter) develops a spontaneous bleeding. Severe thrombocytopenia(< 10,000/microliter) does a fatal organ bleeding.

Antineoplastic Agents↗

PubMed2002

Visualization by comprehensive microarray analysis of gene expression programs during transdifferentiation of mesophyll cells into xylem cells.

Plants have a unique transdifferentiation mechanism by which differentiated cells can initiate a new program of differentiation. We used a comprehensive analysis of gene expression in an in vitro zinnia (Zinnia elegans L.) culture model system to gather fundamental information about the gene regulation underlying the transdifferentiation of plant cells. In this model, photosynthetic mesophyll cells isolated from zinnia leaves transdifferentiate into xylem cells in a morphogenic process characterized by features such as secondary-wall formation and programmed cell death. More than 8,000 zinnia cDNA clones were isolated from an equalized cDNA library prepared from cultured cells transdifferentiating into xylem cells. Microarray analysis using these cDNAs revealed several types of unique gene regulation patterns, including: the transient expression of a set of genes during cell isolation, presumably induced by wounding; a rapid reduction in the expression of photosynthetic genes and the rapid induction of protein synthesis-associated genes during the first stage; the preferential induction of auxin-related genes during the subsequent stage; and the transient induction of genes closely associated with particular morphogenetic events, including cell-wall formation and degradation and programmed cell death during the final stage. This analysis also revealed a number of previously uncharacterized genes encoding proteins that function in signal transduction, such as protein kinases and transcription factors that are expressed in a stage-specific manner. These findings provide new clues to the molecular mechanisms of both plant transdifferentiation and wood formation.

Asteraceae↗

PubMed2002

Age-adjusted mortality and its association to variations in urban conditions in Shanghai.

The objective of this study was to explore the association between health and urbanization in a megacity, Shanghai, by calculating the age-adjusted mortality ratio by ward-unit of Shanghai and by examining relationships between mortalities and urban indicators. Crude mortality rates and age-adjusted mortality ratios by ward-unit were calculated. Demographic, residential environment, healthcare, and socioeconomic indicators were formulated for each of the ward-units between 1995 and 1998. Correlation and Poisson regression analyses were performed to examine the association between urban indicators and mortalities. The crude mortality rate by ward-unit in 1997 varied from 6.3 to 9.4 deaths per 1000 population. The age-adjusted mortality ratio in 1997 by ward-units as reference to the average mortality of urban China varied from 57.8 to 113.3 within Shanghai. Age-adjusted mortalities were inversely related with indicators of a larger floor space of dwellings per population, a larger proportion of parks, gardens, and green areas to total land area; a greater number of health professionals per population; and a greater number of employees in retail business per population. Spacious living showed independent association to a higher standard of community health in Shanghai (P < 0.05). Consequences of health policy and the developments of urban infrastructural resources from the viewpoint of the Healthy Cities concept were discussed.

Age Factors↗

PubMed2002

A combination of an extrapolation method and a benchmark method to develop quantitative health targets for Japan.

The aim of the present study was to propose a methodology to formulate quantitative health targets which combined an extrapolation method and a benchmark method, and to estimate the targets for mortality rates (Mb) for selected causes of death by the year 2010 in Japan. Using the extrapolation method, based on the nationwide Mt from 1988 to 1997, the Mt in 2010 was predicted using a regression model. Using the benchmark method, the paired-mean of the age-adjusted mortality rates (Mts) of the top five prefectures among 47 prefectures was calculated as the benchmark. Combining the predicted mortality and the benchmark mortality, year 2010 targets were determined. As a results year 2010 targets as percentages compared with Mt in 1997 for cancer at all sites, stomach cancer, lung cancer, colo-rectal cancer, liver cancer and stroke were estimated to be 93, 52, 94, 102, 53 and 52% for males, and 84, 43, 86, 82, 60, and 45%, for females, respectively. The methodology presented in this article could be used as a standard procedure to formulate realistic quantified health targets, which can be adopted to develop health policies in nations, regions and communities.

Benchmarking↗

PubMed2002

[Healthy Cities projects in Europe].

The WHO Healthy Cities Project has been developed in Europe to place health high on the agenda of city decision-makers. It has promoted comprehensive local strategies for health and sustainable development. Cities endorse principles and strategies, establish project infrastructures, work on specific goals, products, changes, and outcomes, and invest in formal and informal networking and cooperation. Consistent research and development efforts are contributing towards a more evidence-based policy making and to the emergence of a framework to meet the demands of the new public health movement.

Europe↗