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Biomedical subjects

H Arima

Publications and source records attributed to H Arima.

88 records · Page 5Linked to original sources
PubMed1989

Sustained release of buserelin acetate, a luteinizing hormone-releasing hormone agonist, from an injectable oily preparation utilizing ethylated beta-cyclodextrin.

The possible use of heptakis (2,6-di-O-ethyl)-beta-cyclodextrin (DE-beta-CyD) as a parenteral sustained-release carrier for buserelin acetate, a luteinizing hormone-releasing hormone superagonist, has been examined. The in-vitro release of buserelin from the oily suspension was significantly retarded by the complexation with DE-beta-CyD, mainly due to the poor water solubility of the complex. A single subcutaneous injection of the suspension containing the buserelin-DE-beta-CyD complex to rats provided an effective continuous plasma level of buserelin lasting for at least one month, indicating a potential therapeutic efficacy for the treatment of the endocrine-dependent diseases. These results suggest that DE-beta-CyD serves as an injectable sustained-release drug carrier suitable for chronic treatment with buserelin acetate.

Animals↗
PubMed1986

Imidazo[2,1-b]benzothiazoles. 2. New immunosuppressive agents.

A series of 2-phenylimidazo[2,1-b]benzothiazole derivatives was prepared and tested for immunological activities. Some of the compounds showed significant suppressive activity of delayed type hypersensitivity (DTH) without inhibition of humoral immunity in mice by oral administration. The most active compound was 2-(m-hydroxyphenyl)imidazo[2,1-b]benzothiazole (20).

Animals↗
PubMed1986

Stereoselectivity of a potent calcium antagonist, 1-benzyl-3-pyrrolidinyl methyl 2,6-dimethyl-4-(m-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate.

Four enantiomers (3a-d) of the title compound, YM-09730 (3), were synthesized by the reaction of (-)- or (+)-5-(methoxycarbonyl)-2, 6-dimethyl-4-(m-nitrophenyl)-1,4-dihydropyridine-3-carboxylic acid (1a or 1b) with (S)- or (R)-1-benzyl-3-pyrrolidinol (2a or 2b). [3H]Nitrendipine binding affinity and coronary vasodilating activity of these compounds were evaluated. The absolute configuration of the most potent enantiomer (3a) with the longest duration was unequivocally determined to be (S)-1,4-dihydropyridine-C4 and (S)-pyrrolidine-C3 (S,S) by X-ray crystallographic study on 3a X HBr as well as 3a X HCl. The configuration of 1a corresponds to R, and the other enantiomers of 3 were respectively determined by chemical correlation. The potency order of the four enantiomers was (S,S)-3a greater than (S,R)-3b greater than (R,R)-3d greater than (R,S)-3c. Latent chiral characters of nifedipine derivatives with the identical ester groups were assigned by comparison of their puckering modes of 1,4-dihydropyridine (DHP) rings with those found in 3a X HCl or 3a X HBr. On the basis of the assignment, it has been revealed that the (S)-DHP nifedipine derivatives possess the synperiplanar carbonyl group at C5. The conformational restriction may be a factor causing stereoselectivity of antagonism.

Animals↗
PubMed1980

Blood vitamin B1, transketolase and thiamine pyrophosphate (TPP) effect in beriberi patients, with studies employing discriminant analysis.

In recent years, many cases of beriberi have been reported throughout Japan. One may assume that a great many healthy subjects suffer from a subclinical thiamine deficiency. The present study was carried out in order to examine thiamine status in 21 beriberi patients and 674 apparently normal subjects. In the beriberi patients the total vitamin B1 in whole blood and transketolase activity in the hemolysate were significantly lower, and the thiamine pyrophosphate effect was significantly higher, compared to normal subjects. However, these two groups could not be clearly separated by these biochemical parameters because of significant overlap. On analyzing the results of these biochemical parameters by discriminant analysis, beriberi could be diagnosed with an accuracy of 87,7%. Thus, vitamin B1 levels in blood, transketolase activity and the thiamine pyrophosphate effect in the hemolysate are useful biochemical indices for the diagnosis of beriberi. Above all, the thiamine pyrophosphate effect proved to be the most effective parameter in distinguishing the beriberi group from normal subjects.

Adolescent↗
PubMed1978

Roentgeno-histological studies on serial alveolography.

Using the lung obtained from a 22-year-old female at autopsy, roentgeno-histological studies were carried out on serial alveolography. The pulmonary lymphatics were shown to play an important role in the wash-out of the contrast media. The contrast media injected into the alveolus was gradually transferred on and into the alveolar wall and finally entered the subpleural space. Inflow of the contrast media was further noted into the portion probably representing the "juxta-alveolar lymphatic capillary" according to Lauweryns. Since local edema occurs artificially in serial alveolography, the functional aspects of fluid clearance may also be studied simultaneously unlike the conventional alveolography with its emphasis on morphological diagnosis.

Adult↗
PubMedDate not supplied

Enhancement of gene expression by polyamidoamine dendrimer conjugates with alpha-, beta-, and gamma-cyclodextrins.

To improve the transfection efficiency of nonviral vector, we synthesized the starburst polyamidoamine dendrimer conjugates with alpha-, beta-, and gamma-cyclodextrins (CDE conjugates), expecting the synergistic effect of dendrimer and cyclodextrins (CyDs). The (1)H NMR spectroscopic data indicated that alpha-, beta-, and gamma-CyDs are covalently bound to dendrimer in a molar ratio of 1:1. The agarose gel electrophoretic studies revealed that CDE conjugates formed the complexes with plasmid DNA (pDNA) and protected the degradation of pDNA by DNase I in the same manner as dendrimer. CDE conjugates showed a potent luciferase gene expression, especially in the dendrimer conjugate with alpha-CyD (alpha-CDE conjugate) which provided the greatest transfection activity (approximately 100 times higher than those of dendrimer alone and of the physical mixture of dendrimer and alpha-CyD) in NIH3T3 and RAW264.7 cells. In addition, the gene transfer activity of alpha-CDE conjugate was superior to that of Lipofectin. The enhancing gene transfer effect of alpha-CDE conjugate may be attributable to not only increasing the cellular association, but also changing the intracellular trafficking of pDNA. These findings suggest that alpha-CDE conjugate could be a new preferable nonviral vector of pDNA.

3T3 Cells↗