Biomedical subjects

Hiroyuki Ikeda

Publications and source records attributed to Hiroyuki Ikeda.

9 recordsLinked to original sources

PubMed2004

Cytokine adsorptive property of various adsorbents in immunoadsorption columns and a newly developed adsorbent: an in vitro study.

BACKGROUND/AIMS: Cytokines play important roles in the pathophysiology of systemic inflammatory response syndrome (SIRS) and sepsis. Therefore, some effective measures to remove cytokines from the bloodstream could be effective in the treatment of SIRS and sepsis. The aim of this study was to evaluate the cytokine adsorptive property of various adsorbents for the purpose of the development of new selective cytokine adsorption columns. METHODS: The cytokine adsorptive property of adsorbent in a CF-X column, which consists of cellulose beads cross-linked with hexamethylene-di-isocyanate, was compared with those of various adsorbents in currently available immunoadsorption columns, such as Immusorba TR, Immusorba PH, Selesorb, and Lixelle, in vitro batchwise test using patients' plasma. A newly developed adsorbent, MPCF-X, which was modified by coating the surface of the adsorbent in CF-X with 2-methacryloyloxyethyl phosphorylcholine (MPC), was also tested for its cytokine adsorptive property. RESULTS: The adsorbent in CF-X showed a significantly higher adsorption rate for TNF-alpha, interleukin (IL)-6 and IL-10 compared with other adsorbents (p < 0.05). Adsorbent in Lixelle showed good affinity to TNF-alpha and IL-8. Especially, the adsorbent in CF-X almost completely removed TNF-alpha, whereas it also had considerable affinity to normal IgG. MPCF-X showed decreased affinity to IgG with considerable adsorptive properties to cytokines. CONCLUSION: Selective cytokine adsorption columns could be developed with improvement of currently available adsorbents. Such a new selective cytokine adsorption column could be clinically applied for the treatment of SIRS/sepsis.

Adsorption↗

PubMed2004

Multiple fistulas from the coronary arteries to the left ventricle in tricuspid atresia.

It is rare to find multiple fistulas arising from all three coronary arteries and draining into the left ventricle. Coronary angiography revealed this anomaly in a one-year-old girl with tricuspid atresia after conversion to the Fontan circulation. To the best of our knowledge, this is the first report of such multiple fistulas in the setting of tricuspid atresia, and also the first report in childhood.

Coronary Angiography↗

PubMed2004

Absolute configuration of a polyol fragment of blasticidin A, a specific inhibitor of aflatoxin production.

Blasticidin A (1) and aflastatin A (2), Streptomyces metabolites with similar structures, are specific inhibitors of aflatoxin production by Aspergillus parasiticus. The stereochemistry of the polyol fragment of 1 (3a) containing ten chiral centers was elucidated by applying acetonide and MTPA methods to a variety of acetonide derivatives of 3a, which determined the absolute configuration of 3a. By using the similar methods, the absolute configuration of the polyol fragment of 2 (4a) was determined, which was the same as that elucidated by J-based and other chemical methods previously.

Aflatoxins↗

PubMed2004

Differences in facilities' acceptance of patients under long-term care insurance in Japan.

OBJECTIVES: In April 2000, Japan launched a public, long-term care insurance (LTCI) plan for elderly people who need support. This study describes how medical support for the elderly is delivered at LTCI care facilities in Japan now and gaps between system goals and current activity. Recommendations are made for enhancing the implementation of LTCI. METHODS: We mailed questionnaires to all health service facilities for the elderly (HSF) and special nursing homes for the elderly (SNH) located in the Kyushu area of Japan, asking whether they would accept patients with nine specific conditions. RESULTS: We found that HSFs, which are required to employ a full-time doctor and are reimbursed at a higher rate, accept significantly fewer patients with four conditions that need medical support than are accepted by SNHs, which are not required to employ a full-time doctor. DISCUSSION: In this study, we find discrepancies between system goals and current activities at LTCI care facilities. For the Japanese LTCI system to work well in the limitation of medical resources, we must understand how it really works and to reform the system continuously.

Aged↗

PubMed2004

Clinical evaluation of recombinant human growth hormone in Noonan syndrome.

The objective of this study was to investigate the effect of administration of recombinant human growth hormone (hGH) in patients with Noonan syndrome. hGH was administered (0.5 IU/kg/week) to 15 patients with Noonan syndrome over a 2 year period. Average patient age prior to therapy was 7.5 +/- 2.5 (mean +/- SD) yr, the height SD score was -2.8 +/- 0.7, and the pretreatment height velocity and bone age were 4.8 +/- 1.0 cm/yr and 5.8 +/- 2.1 yr, respectively. The height velocity in the year prior to treatment, and 0-12 and 12-24 months after commencing treatment was 4.8 +/- 1.0 cm/yr, 7.0 +/- 1.2 cm/yr, and 5.5 +/- 0.6 cm/yr, respectively. The height velocity in the first year of treatment was significantly greater (P = 0.0001, n = 14) than the pretreatment value, but there was no significant difference in the second year. The height SD scores at the commencement of treatment, and after 12 and 24 months of treatment were -2.8 +/- 0.7, -2.4 +/- 0.7, and -2.2 +/- 0.5, respectively. Bone age advanced by 1.1 +/- 0.5 yr in the 12 months after commencing treatment. We conclude that the use of hGH may be beneficial in the treatment of Noonan syndrome, although further research is required.

Age Determination by Skeleton↗

PubMed2004

Reflux in the left ovarian vein: analysis of MDCT findings in asymptomatic women.

OBJECTIVE: The aim of this study was to clarify the CT features of ovarian vein reflux in asymptomatic women and to determine the possible cause of the reflux. MATERIALS AND METHODS: One hundred ten multiparous or uniparous and 41 nulliparous asymptomatic women were examined on MDCT. Degree, pathway, and associated findings of ovarian vein reflux were evaluated. We measured the diameters of the left renal vein (LRV), the ovarian veins, and the parauterine veins. Ratios of LRV diameters (lateral-aortomesenteric) were obtained. These data were then compared between the women with reflux and those without reflux. RESULTS: Reflux was found in 44% (48/110) of parous and 5% (2/41) of nulliparous women. Reflux flowed into the right ovarian vein through the parauterine and uterine veins in 25 women. Twenty-four of these 25 women were multiparous. In these cases, the parauterine veins showed varicose dilation (5.9 +/- 1.6 mm [mean +/- SD]). There was a statistically significant difference in left ovarian vein diameter (8.3 +/- 2.1 mm vs 4.9 +/- 1.3 mm, p < 0.0001) between parous women with reflux and those without reflux, respectively. The LRV diameter ratio (lateral-aortomesenteric) was also statistically significant (3.6 +/- 1.3 vs 1.7 +/- 0.7, p < 0.0001) between the same two groups. CONCLUSION: Reflux into the left ovarian vein is seen up into the contralateral ovarian plexus by passing through the dilated parauterine and uterine veins. This CT finding is common in asymptomatic multiparous women. Narrowing of the LRV at its aortomesenteric portion can be one of the causes of such reflux.

Adult↗

PubMed2002

Isolation and characterization of 2-nitroimidazole produced by Streptomyces species as an inhibitor of both carbonic anhydrase and shell formation in the barnacle Balanus amphitrite.

Carbonic anhydrase is thought to be involved in the process of calcium carbonate deposition in calcified tissues of many organisms. Barnacles form hard calcified shells for protection against predation, and represent a class of marine-fouling animals. In order to inhibit barnacle growth by inhibiting shell formation, we searched for carbonic anhydrase inhibitors from microbial secondary metabolites. A simple assay for assessing carbonic-anhydrase-inhibiting activity was developed. Screening of many microorganisms isolated from soil with this assay resulted in a microbial strain that produced a carbonic anhydrase inhibitor. This strain was identified as Streptomyces eurocidicus mf294. The inhibitor was isolated through 4 purification steps and identified as 2-nitroimidazole on the basis of spectroscopic data. 2-Nitroimidazole inhibited barnacle carbonic anhydrase dose-dependently and complete inhibition was reached at the concentration of 1 x 10(-5) M. 2-Nitroimidazole did not affect settlement or metamorphosis of barnacle larvae, but inhibited shell formation at concentrations higher than 1 x 10(-4) M. These findings strongly support the idea that carbonic anhydrase is involved in calcification.

Journal Article↗

PubMed2002

[Not Available].

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Journal Article↗

PubMedDate not supplied

Chemoselective protection of the amino groups of chitosan by controlled phthaloylation: facile preparation of a precursor useful for chemical modifications.

A simple and convenient procedure for chemoselectively protecting the amino groups of chitosan has been developed to provide N-phthaloyl-chitosan that is indispensable as a soluble N-protected precursor for further controlled modification reactions of chitosan. Although the conventional N-phthaloylation of chitosan in N,N-dimethylformamide was accompanied by partial phthaloylation of the hydroxy groups, the addition of a small amount of hydroxy-containing compounds effectively suppressed the O-phthaloylation. Of some compounds examined, water proved particularly suitable, resulting in the formation of chemoselectively N-phthaloylated chitosan without any appreciable O-phthaloyl groups. The resulting N-phthaloyl-chitosan was found to be crystalline despite the presence of a bulky substituent. A solubility test indicated that N-phthaloyl-chitosan exhibited considerable affinity for organic solvents.

Acetylation↗