Biomedical subjects

Mieko Kimura

Publications and source records attributed to Mieko Kimura.

8 recordsLinked to original sources

PubMed2005

Values of water-soluble vitamins in blood and urine of Japanese young men and women consuming a semi-purified diet based on the Japanese Dietary Reference Intakes.

We investigated the levels of water-soluble vitamins except for vitamin B6 in the blood and urine of Japanese college male (n = 10) and female (n = 10) students. They consumed for 7 d a semi-purified diet based on Japanese Dietary Reference Intakes to assess the Recommended Dietary Allowances (RDA) for water-soluble vitamins and to present some new normal values for blood and urine levels of water-soluble vitamins in Japanese. The blood and the 24-h urine samples were collected on the last day of the experiment and measured. The values of total vitamin B1 in whole blood, total vitamin B2 in whole blood, total cyanocobalamin in serum, total nicotinamide in whole blood, total pantothenic acid in whole blood, total folates in serum, total biotin in serum, and ascorbic acid in plasma were 104+/-17 pmol/mL (mean+/-SD), 216+/-25 pmol/mL, 0.34+/-0.05 pmol/mL, 59.1+/- 5.0 nmol/ mL, 2.45+/-0.37 nmol/mL, 15.6+/-4.6 pmol/mL, 8.3+/-0.5 pmol/mL, and 62+/-10 nmol/mL, respectively, in males, and 90+/-23, 234+/-18, 0.67+/-0.20, 61.9+/-6.0, 2.48+/-0.30, 30.2+/-8.6, 8.4+/-0.3, and 67+/-14, respectively, in females. There was a significant difference in the values of cyanocobalamin and total folates between men and women. The urinary excretion of vitamin B1, vitamin B2, cyanocobalamin, sum of the catabolic metabolites of nicotinamide, pantothenic acid, folates, biotin, and ascorbic acid were 665+/-114 nmol/d, 562+/-325 nmol/d, 93+/-31 pmol/d, 84+/-26 micromol/d, 9.3+/-2.3 micromol/d, 19.4+/-2.8 nmol/d, 83+/-18 pmol/d, and 148+/-51 micromol/d, respectively, in males, and 495+/-212, 580+/-146, 145+/-49, 83+/-19, 16.9+/-1.3, 22.7+/-2.7, 83+/-23, and 140+/-51, respectively, in females. There was a significant difference in the urinary excretion of cyanocobalamin, pantothenic acid and total folates between men and women. These values will be useful for the nutritional assessment of water-soluble vitamins for Japanese, although the examination period was short. In future, an experiment with various age groups and re-evaluation by repeated experiments will provide more accurate values.

Adult↗

PubMed2005

[Magnesium for nutrition].

Magnesium plays an essential role in a very wide range of fundamental cellular reactions. The deficiency in the organism may lead to serious biochemical and symptomatic changes. In 1932, McCollum and coworkers made the first systematic observations of magnesium deficiency in rats and dogs. In 1934, the first description of clinical depletion in man was published in patients with various underlying diseases. In the early 1950, Flink and coworkers documented depletion of magnesium ion in alcoholics and in patients on magnesium-free i.v. solutions. In this paper, the biochemical and nutritional function, and nutritional essentiality for magnesium are reviewed.

Animals↗

PubMed2004

A study on spontaneously obese rat (Minko rat) with abnormal lipid metabolism, strength and mineral concentrations in bone.

OBJECTIVES: In view of the prevalence of osteoporosis in Japan, which surveys have shown has almost doubled over the last ten years, contributory factors, additional to the mineral status, that affect bone stiffness have been explored in spontaneously obese (Minko) rats. METHODS: Bone stiffness and strength as well as content of Mg, Ca, P, Na, K, and trace minerals in femurs were compared in male and female Minko rats, which have abnormal lipid metabolism. RESULTS: Mechanical study of femurs indicated that bone stiffness of male rats was significantly higher than that of female rats, but that Mg, Ca, P, Na, Zn, Sr and Fe concentrations in male rats were significantly lower than that of female rats, while S and K concentrations in male rats were significantly higher than that of female rats. CONCLUSIONS: These results suggest that bone strength isn't determined only by mineral concentrations such as Mg, Ca and P. We reported that the bone strength of "Minko Rats" was significantly higher than bone strength of control rats, but there was no significant difference of Ca and P concentrations between the two groups of rats.

Animals↗

PubMed2004

Developed determination method of ultra trace elements and ultra trace element levels in plasma of rat fed low magnesium diet.

BACKGROUND: Homeostatic mechanisms keep plasma mineral concentrations largely unchangeable, and are not always reflective of the nutritional status. For that reason, nutritional assessment is difficult and another biological index may be of value. Recently, improvement of measuring instruments has permitted more accurate measurement of trace and ultra trace elements. METHODS: A new determination method for trace and ultra trace elements in rat plasma, that uses an inductively coupled plasma mass spectrometry (ICP-MS Elan-6000, Perkin Elmer, Co., USA) without pre-treatment has enabled study of basic data of ultra trace element concentrations for the first time. RESULTS: The effect of low magnesium (Mg) intake, as compared with the effect of a normal diet, status of 10 trace and ultra trace element status was studied in 12 young male Wistar rats (3-weeks-old), divided into two groups and fed a normal diet or low Mg diet for 4 weeks. The plasma was diluted with ultra pure water (TAMAPURE-AA: Tama Chemical Co., Japan). Ten trace and ultra trace element (As: 75, Se: 82, Rb: 85, Sr: 87, Mo: 95, Ba: 137, Ta: 181, Ir: 193, Au: 197, Pb: 208) concentrations in the plasma were measured with ICP-MS Elan 6000. As, Rb, Sr, Ta, Ir and Au concentrations were significantly high in the plasma of low Mg rats, compared to levels in rats fed normal diets. Essentiality for mammals has been certified for Se, Rb, Mo, As and Pb, but not yet for Sr, Ba, Au, Ir and Ta. CONCLUSIONS: These results prove that trace and ultra trace element concentrations in plasma are changeable by nutritional conditions, and suggest that new physiological functions may be found for these elements, and that they may be proved to be essential for mammals.

Animals↗

PubMed2003

Carotenoid composition of hydroponic leafy vegetables.

Because hydroponic production of vegetables is becoming more common, the carotenoid composition of hydroponic leafy vegetables commercialized in Campinas, Brazil, was determined. All samples were collected and analyzed in winter. Lactucaxanthin was quantified for the first time and was found to have concentrations similar to that of neoxanthin in the four types of lettuce analyzed. Lutein predominated in cress, chicory, and roquette (75.4 +/- 10.2, 57.0 +/- 10.3, and 52.2 +/- 12.6 microg/g, respectively). In the lactucaxanthin-containing lettuces, beta-carotene and lutein were the principal carotenoids (ranging from 9.9 +/- 1.5 to 24.6 +/- 3.1 microg/g and from 10.2 +/- 1.0 to 22.9 +/- 2.6 microg/g, respectively). Comparison of hydroponic and field-produced curly lettuce, taken from neighboring farms, showed that the hydroponic lettuce had significantly lower lutein, beta-carotene, violaxanthin, and neoxanthin contents than the conventionally produced lettuce. Because the hydroponic farm had a polyethylene covering, less exposure to sunlight and lower temperatures may have decreased carotenogenesis.

Antioxidants↗

PubMed2003

Geographical variation in nutrient intake between urban and rural areas of Jiangsu province, China and development of a semi-quantitative food frequency questionnaire for middle-aged inhabitants.

The intake of food and nutrients differs between urban and rural areas in China. To develop a practical semi-quantitative food frequency questionnaire to cover both the urban and rural areas, we conducted diet surveys and compared food and nutrient intake between the two areas. We recruited 198 urban and 214 rural healthy inhabitants aged 35-55 years, and performed diet surveys, using a 3-day weighed dietary record approach. The intake of 29 nutrients was calculated according to actual consumption of foods, with Standard Food Composition Tables for China and Japan. Then, contribution analysis and multiple regression analysis were employed to select food items covering up to a 90% contribution and a 0.90 R2 of coefficient of determination, respectively. Consumption of energy and carbohydrates was greater in the rural area, but mean protein intake was higher in the urban case. Values for total fat were greater for rural than for urban males, with animal fat as the major contributor. We finally selected 117 and 76 food items for the urban and rural semi-quantitative food frequency questionnaires, respectively, covering 18 and 27 nutrients constituting up to 90% of the nutrient intake. Further validity and reproducibility tests are now needed to assess their appropriateness for usage.

Adult↗

PubMed2003

Measurement of retinoids and beta-carotene 15,15'-dioxygenase activity in HR-1 hairless mouse skin with UV exposure.

We investigated the vitamin A status and beta-carotene 15,15'-dioxygenase activity in hairless mice with UV exposure to assess the regulation of vitamin A metabolism after UV irradiation. HR-1 hairless mice were irradiated with UV at 3 J/cm2 for 5 d. After UV irradiation, the mice were sacrificed and samples were obtained to analyze the retinoid concentration, expression of RXR-alpha, and beta-carotene 15,15'-dioxygenase activity. After UV exposure, the skin retinoid concentration was significantly lower as well as the expression of RXR-alpha. Higher skin beta-carotene dioxygenase activity was observed in the UV group as compared to the control group. We found no significant differences in the alpha-tocopherol concentration or acrolein levels in the skins of the two groups. In conclusion, the elevation of beta-carotene 15,15'-dioxygenase activity in hairless mice after UV exposure may be a response to reduction of the skin retinoid concentration.

Animals↗

PubMed2002

[Not Available].

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Journal Article↗