Search PubMed⌕ Search

Biomedical subjects

M Ikeda

Publications and source records attributed to M Ikeda.

At least 865 records · Page 48Linked to original sources

Continuous stimulation of gonadotropin-releasing hormone (GnRH) receptors by GnRH agonist decreases pituitary GnRH receptor messenger ribonucleic acid concentration in immature female rats.

Although it is well recognized that continuous administration of gonadotropin-releasing hormone agonist (GnRHa) induces pituitary desensitization, the precise molecular mechanism of this phenomenon is still unclear. To test the hypothesis that pituitary gonadotroph desensitization is mediated by a change in GnRH receptor (GnRH-R) gene expression, the GnRH-R mRNA concentration was analyzed in immature female rats during GnRHa treatment. Northern blot hybridization was used to determine the GnRH-R mRNA concentration several times after an injection of TAP-144-SR, a slow releasing GnRHa. The GnRH-R mRNA readings were 92.7 +/- 9.5%, 49.9 +/- 5.0%, 35.7 +/- 2.3% and 73.8 +/- 5.7% (Mean +/- SD) compared to each control value at 1, 2, 4 and 8 weeks, respectively, after a single injection of 0.94 mg TAP-144 SR. These changes in GnRH-R mRNA coincided with the changes in gonadotropin secretion and LH-beta mRNA in response to GnRH in the results of our previous report. The present results indicate that the reduction of the number of pituitary GnRH-R sites induced by continuous stimulation with GnRHa is regulated at a transcriptional level.

Animals↗

Disappearance of differences in nutrient intake across two local cultures in Japan: a comparison between Tokyo and Kyoto.

Nutritional survey was conducted in a winter season of 1992 3 by collecting seventy-one 24-hour food duplicate samples from three groups of middle-aged women (22 to 25 subjects per group) in traditional residential areas in the cities of Tokyo (two groups) and Kyoto (one group), two cultural centers in Japan known to have different food customs. The analysis in terms of intake of nutrients such as energy, carbohydrate, protein, lipid, minerals, vitamins and fibers did not show significant difference among the three groups studied. Sodium chloride intake also did not differ. Daily consumption of food materials (evaluated as classified in terms of, e.g., cereals, meat, fish and vegetables) was similar. Relative weight of three meals and snacks in energy intake did not vary among the groups. Consumption of milk and bread as indicators of intake of non-traditional food was also comparable among the groups. The observation as a whole suggests that the different food custom once known to be present between the two local cultures is no longer detectable. Nationwide extensive transport of food materials is discussed as one of possible causes.

Animals↗

Chronological changes and inter-regional differences in dietary fiber intakes among middle-aged Japanese women.

Dietary fiber intake was estimated by the total food duplicate method, using a computerized system for fiber calculation recently developed by this study group. Collection of food duplicates were conducted twice, once in 1979-83 and then in 1990-95, in 20 sites across Japan. Altogether 294 and 384 nonsmoking, nonhabitually drinking adult women offered the samples, in the first and second survey, respectively. The average intake of total fiber was 20.7 g/day in the first study, and it was 18.7 g/day in the second survey with a significant reduction. Soluble fiber accounted for 18 to 19%, and the reduction was more marked in soluble fiber than in insoluble fiber. There was an inter-regional difference in fiber intake which was more evident in the first survey than in the second; farmers in Okinawa took less soluble, insoluble and total fiber than in Hokkaido and Honshu farmers and also urban residents. Throughout the four groups, the leading fiber sources were vegetables, followed by cereals, fruits and pulse in the decreasing order. Intakes of these foods diminished during the two survey period, and the reduction of fiber from cereals was most evident in Honshu and Okinawa farmers. International comparison showed that the current level of fiber intake in Japan is essentially similar to the levels in Europe and USA, despite the long-term trend of reduction.

Adult↗

Shift in sodium chloride sources in past 10 years of salt reduction campaign in Japan.

Twenty four-hr total food duplicate samples were collected from nonsmoking house-wives (aged mostly 30 to 60 years) twice at a 10-year interval in winter seasons, once in around 1980 and then in around 1990 in 11 prefectures in Japan. In practice, 342 and 472 samples were obtained in the 1980 and 1990 studies, respectively. Sodium chloride (NaCl) intake via each food item was estimated from the weight of the item in the duplicate. The comparison of 1990 results with 1980 results showed that the total NaCl intake (i.e., NaCl intake via all food items) decreased after a 10-year campaign to lower salt intake. The NaCl/energy ratio however stayed essentially unchanged. Whereas NaCl intake via pickles decreased remarkably and that via miso paste [a fermentation product of soy bean, rice (or wheat) and salt] slightly, the decreases were counteracted by a substantial increase in NaCl intake via soy bean sauce. Meaning of this unexpected counteraction was discussed in relation to the difficulties in the campaign to lower salt intake.

Adult↗

Nutritional evaluation of working Malay women in Kuala Lumpur as studied by total food duplicate method.

Nutrient intake was surveyed by the total food duplicate method in 49 adult ethnically Malay women (at the ages of 18 to 47 years and mostly at 30-39 years) working in Kuala Lumpur, Malaysia. Simultaneously, hematological examinations, serum biochemistry, anthropometry and clinical examination were conducted. Nutrient intakes were estimated in reference to the weight of each food item and the standard food composition tables. Lunch was the most substantial meal of the day with rice as a staple food. Compared with the Recommended Dietary Allowance (RDA) values, daily intakes of energy (1,917 kcal as an arithmetic mean), protein (62.2 g), vitamin B1 (0.83 mg) and vitamin B2 (1.18 mg) were sufficient, but intakes of minerals [i.e., calcium (347.8 mg) and iron (12.5 mg)] and some vitamins [i.e., vitamin A (equivalent to 627 micrograms retinol) and niacin (7.84 mg)] were less than RDA. When evaluated on an individual basis, the prevalence of those who took less than 80% RDA was highest for iron (92%), followed by niacin (80%), calcium (57%) and vitamin A (57%). The presence of 7 hypohemoglobinemia cases may be related to the insufficient iron intake. Overweight cases (14 women) were also detected, the prevalence of which increased at advanced ages. Lipid intake was rather high (28% of total food on energy basis), for which the major source was plants with limited contribution from fish/shellfish.

Adolescent↗

Nitric oxide inhibits intracellular adhesion molecule-1 expression in rat mesangial cells.

This study tested whether nitric oxide modulates the expression of intercellular adhesion molecule-1 (ICAM-1) expression in glomerular mesangial cells. In an enzyme-linked immunosorbent assay, interleukin 1 beta (IL-1 beta; 10 ng/mL) increased ICAM-1 molecule expression on cultured rat mesangial cell surface in a time-dependent manner. Addition of the nitric oxide donors 3-morpholino-sydnonimine (SIN-1) or sodium nitroprusside significantly suppressed IL-1 beta-induced ICAM-1 molecule expression in a dose-dependent manner. The inhibitory effect of SIN-1 was abolished in the presence of a nitric oxide scavenger hemoglobin, but not in the presence of superoxide dismutase or pyrrolidine dithiocarbamate. Addition of 8-bromo-cyclic GMP showed no significant effect on IL-1 beta-induced ICAM-1 expression. In Northern blot analysis, the expression of ICAM-1 mRNA was barely detected in unstimulated cells, whereas ICAM-1 gene transcripts were clearly expressed after exposure to IL-1 beta for 3 h, and addition of SIN-1 decreased IL-1 beta-induced ICAM-1 mRNA accumulation. These results suggest that nitric oxide suppresses ICAM-1 expression in IL-1 beta-stimulated mesangial cells, independent of cGMP formation.

Animals↗

A case for the adoption of pharmacoeconomic guidelines in Japan.

In recent years, more and more Japanese pharmaceutical companies have been submitting pharmacoeconomic data to the government, following the official request that such data may help in setting pharmaceutical prices. The companies have cooperated because, by doing so, they could influence pricing decisions for new products. However, the quality of these data at present is considered to be poor and heavily biased. The introduction of pharmacoeconomic guidelines that outline a set of standardised factors to be included in evaluations are necessary, so that an appropriate comparison of the cost effectiveness of the many new drugs that are introduced into the Japanese market each year can be made. In addition to supporting the development of standardised guidelines, the Ministry of Health and Welfare should clarify how pharmacoeconomic data are to be used to aid policy decisions and also mandate the publication of pharmacoeconomic data.

Drug Costs↗

Hypercholesterolemia and the progression of the renal dysfunction in chronic renal failure patients.

The effect of hyperlipidemia on the progression of chronic renal failure was investigated in 104 chronic renal failure patients, aged 39.3 +/- 2.9 years. The follow up period was 4.1 +/- 2.9 years. The serum creatinine level was 2.1 +/- 1.1 (mean +/- SD) mg/dl at the beginning of study and increased to 8.7 +/- 4.4 mg/dl at the end of the study. The reciprocal serum creatinine concentration (1/Cr) was plotted against the observation time, and the slope was calculated. The absolute value of the slope was used as the progression rate of renal impairment. The progression rate was positively related to total cholesterol level or urinary protein score, while it was negatively related to total protein level. Without the influence of urinary protein score, the progression rate correlated with total cholesterol level. The result suggests that hypercholesterolemia may be an independent aggravating factor in the progression of renal dysfunction in chronic renal failure patients.

Adolescent↗

Test anxiety and working memory system.

The purpose was to examine the effect of test anxiety on deficits in the articulatory loop in the working memory system. We used a verbal memory task to occupy the articulatory loop and a spatial memory task to occupy the visuospatial scratch pad. 17 highly test-anxious and 19 low-anxiety subjects performed both tasks under an anxiety-inducing situation during which they were observed by a monitor camera. Percentage of correct responses and reaction times were measured as indices of task performance. Highly anxious subjects reported feeling worry and cognitive self-concern more than the low-anxiety group. Highly anxious subjects showed a longer mean reaction time on the verbal memory task than the low-anxiety group. On the spatial memory task there was no difference in quality of performance. This finding might suggest that anxiety such as worry and cognitive self-concern interferes with information processing in the articulatory loop of the working memory system.

Achievement↗

[Evaluation of gustatory threshold changes in healthy subjects].

Changes in gustatory thresholds were examined in 30 healthy volunteers by conducting electrogustometry and the filter-paper disc method, three times with a 4 week or longer interval. Gustatory thresholds, obtained from either method, notably decreased in the second and the third examination in many subjects. In chronological observations by using the electrogustometry, changes of 6 dB or less in the chorda tympani nerve area or 8 to 10 dB less in the glossopharyngeal nerve area were considered to be not significant. In the filter-paper disc method, the threshold changes with one concentration grade of test solution were observed at high frequency, while the threshold changes with two concentration grades or more were very rare, however all changes were significant. In the filter-paper disc method, changes of the gustatory threshold in one or two kinds of tastes were relatively frequently observed. However, the gustatory thresholds of three or four kinds of tastes rarely changed simultaneously even by one concentration grade of those taste solutions. If such multiple changes of the taste thresholds occur, even when each taste threshold changed only by one concentration grade, it was as a significant change.

Adolescent↗

[Social network and social support for married women and their spouses].

This study investigated various psychological aspects of social networks of married women and their spouses A survey data for 259 women and 185 men were analyzed, and main findings were as follows: 1. With marriage, support agents of women and men change extensively in their social networks. Wives have more variety in support agents within their social network, through children to their friends' parents. On the other hand, husbands' agents are likely to be confined to their wives and children. 2. Wives and husbands are similar in that their first choice for seeking advice is their spouse. A friend is the second choice for both of them. While parents, brothers and sisters serve as wives' third choice, there is no third for husbands. 3. Enrichment of wives' social network, based on a well-functioning relationship with husbands, leads to a lower degree of social isolation experienced by them.

Adult↗

Binding of macrophage colony-stimulating factor to serum proteins.

Although three molecular forms of macrophage colony-stimulating factor (M-CSF) have been reported, Western blot analysis of immunoaffinity-purified M-CSF from human blood has shown that the major species of M-CSF in the serum has a molecular weight (MW) of 85 kD. Superose-12 gel filtration chromatography of immunoaffinity-purified serum M-CSF showed the presence of M-CSF-positive fraction in a higher MW area compared with the elution profile of recombinant human (rh) 85-kD M-CSF. Western blot analysis of the higher MW fraction showed that the M-CSF was the same as rh 85-kD M-CSF (not proteoglycan form of M-CSF), indicating that, in the serum, M-CSF exists bound to some serum proteins. To detect the serum proteins, we performed M-CSF-bound column chromatography. The eluate contained at least three serum proteins including albumin and IgG. This result was supported by chromatography using biotinylated M-CSF and avidin-agarose. The binding between rhM-CSF and albumin or IgG was also demonstrated by high-performance liquid chromatography (HPLC) fractionation of the mixture and enzyme-linked immunosorbent assay (ELISA) of the fractions. In the serum, a fraction of M-CSF seems to be complexed with serum proteins such as albumin and IgG.

Animals↗