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Biomedical subjects

K Yoshii

Publications and source records attributed to K Yoshii.

At least 55 records · Page 3Linked to original sources
PubMed1997

Sustained release of flufenamic acid from a drug-triacetyl-beta-cyclodextrin complex.

Triacetyl-beta-cyclodextrin (TA-beta-CyD), a hydrophobic cyclodextrin derivative that is insoluble in water, was used to form a complex with flufenamic acid (FA). Complexes of FA with TA-beta-CyD (FA-TA-beta-CyD) at various molar ratios (1:1, 1:2, 1:3) were prepared by a kneading method, using ethanol as a solvent. FA-TA-beta-CyD complex formation was demonstrated by differential scanning calorimetry and powder X-ray diffractometry. The release rate of FA from the FA-TA-beta-CyD complexes was measured in both the Japanese Pharmacopoeia XII 1st fluid pH 1.2 and isotonic phosphate buffer pH 6.8. The release rate of FA from the FA-TA-beta-CyD complexes in the isotonic phosphate buffer pH 6.8 was significantly retarded compared to the release rate of FA from the FA-glucose mixture. After 1 h, 100% of the drug was released from the FA-glucose mixture and 10-25% was released from the complexes. When either the powder of the FA-glucose mixture or the FA-TA-beta-CyD mixture was administered directly into the intraduodenal lumen in rats, the plasma concentration of FA reached a maximum level within 40 min after administration. On the other hand, when the FA-TA-beta-CyD complexes were administered into the intraduodenal lumen, the plasma concentration of FA did not show a sharp peak, but remained at a plateau level (10-18 microg/ml) for 6-8 h. An increased mean residence time of FA following FA-TA-beta-CyD complexes administration was observed; however, the AUC(0-10) for the FA-TA-beta-CyD complexes showed no significant difference from that for the FA-TA-beta-CyD mixture. These results indicate that TA-beta-CyD may serve as a hydrophobic carrier in sustained-release preparations of FA. The drug-TA-beta-CyD complexes may therefore be useful in oral administration to achieve prolonged action and reduced side effects.

Absorption↗
PubMed1997

[3 Cases of blunt chest trauma].

3 Cases of blunt chest trauma were reported, including aortic isthmus rupture, diaphragmatic injury and right main bronchial rupture. All cases were injured by traffic accidents. The first case was a 21-year-old man complicated with aortic injury and femoral bone fracture and died of intrapleural rupture before thoracotomy. The second case was a 49-year-old man who had right 11th rib fracture and he received emergent thoracotomy due to hemorrhagic shock. We found accidentally arterial massive bleeding by the diaphragmatic injury at thoracotomy and ligated directly. The third case was a 19-year-old man and he was unconscious on admission and rupture of the right main bronchus was found by bronchofiberscope and performed pneumectomy. One patient died and other two patients have survived. Blunt chest trauma sometimes lead to fatal damage of vital organs. So it is necessary to make early diagnosis and perform the emergent operations for life salvage.

Accidents, Traffic↗
PubMed1997

[Epinephrine Bitartrate Reference Standard (Control 951) of National Institute of Health Sciences].

The raw material for epinephrine bitartrate was tested for preparation of the "Epinephrine Bitartrate Reference Standard (Control 951)" of National Institute of Health Sciences. Analytical data obtained were as follows: melting point, 148.6 degrees C (decomposition); UV spectrum, lambda max = 279 nm; IR spectrum, the same as that of JP Epinephrine Bitartrate Reference Standard (Control 792); optical rotation, [alpha]20D = -52.8 degrees; thin-layer chromatography, one impurity was detected; high-performance liquid chromatography, no impurity was detected; loss on drying, 0.01%; assay, 99.6% by potentiometric titration, 100.3% by spectrophotometry. Based on the above results, the raw material was authorized as the Epinephrine Bitartrate Reference Standard (Control 951) of National Institute of Health Sciences (Japanese Pharmacopoeia).

Epinephrine↗
PubMed1997

[Riboflavin Reference Standard (Control 951) of National Institute of Health Sciences].

The raw material for riboflavin was tested for preparation of the "Riboflavin Reference Standard (Control 951)" of National Institute of Health Sciences. Analytical data obtained were as follows: melting point, 284.6 degrees C (decomposition): specific absorbance, E1cm1% = 857 (267 nm), 277 (373 nm), 326 (445 nm); IR spectrum, the same as that of JP Riboflavin Reference Standard (Control 921); optical rotation, [alpha]20D = -135.6 degrees; thin-layer chromatography, three impurities were detected; high-performance liquid chromatography, a small amount of 10 impurities were detected: loss on drying, 0.10%; assay, 100.4% by spectrophotometry. Based on the above results, the raw material was authorized as the Riboflavin Reference Standard (Control 951) of National Institute of Health Sciences (Japanese Pharmacopoeia).

Japan↗
PubMed1997

[Estradiol Reference Standard (Control 961) of National Institute of Health Sciences].

The raw material for estradiol was examined for preparation of the "Estradiol Reference Standard (Control 961)" of National Institute of Health Sciences. Analytical data obtained were as follows: melting point, 179.1 degrees C; UV spectrum, lambda max = 281 nm; IR spectrum, the same as that of the Estradiol Reference Standard of National Institute of Health Sciences (Control 931); optical rotation, [alpha]20D = +79.5 degrees; thin-layer chromatography, one impurity was detected; high-performance liquid chromatography (HPLC), a trace amount of three impurities were detected; loss on drying, 3.17%; assay, 99.4% by UV spectrophotometry and 99.0% by HPLC. Based on the above results, the raw material was authorized as the Estradiol Reference Standard (Control 961) of National Institute of Health Sciences.

Estradiol↗
PubMed1997

[dl-Camphor Reference Standard (Control 961) of National Institute of Health Sciences].

The raw material of dl-camphor was examined for the preparation of the "dl-Camphor Reference Standard (Control 961)" of National Institute of Health Sciences. Analytical data obtained are as follows: UV spectrum, lambda max = 290 nm; IR spectrum, the same as that of the present JP Camphor Reference Standard (Control 953); melting point, 179.1 degrees C; purity test by gas-chromatography (GC), three kinds of impurities were detected; assay by GC, 99.8%. Based on the above results, the candidate raw material was authorized as the dl-Camphor Reference standard (Control 961) National Institute of Health Sciences (Japanese Pharmacopoeia).

Camphor↗
PubMed1997

[Chlormadinone Acetate Reference Standard (Control 961) of National Institute of Health Sciences].

The raw material for chlormadinone acetate was tested for preparation of the "Chlormadinone Acetate Reference Standard (Control 961)" of National Institute of Health Sciences. Analytical data obtained were as follows: melting point, 215. 3 degrees C; UV spectrum, lambda max = 283.5 nm; IR spectrum, the same as that of JP Chlormadinone Acetate Reference Standard (Control 885); optical rotation, [alpha]20D = -13.0 degrees; thin-layer chromatography, one impurity was detected; high-performance liquid chromatography, two impurities were detected; loss on drying, 0.01%; assay, 99.4% by spectrophotometry and 99.5% by HPLC. Based on the above results, the raw material was authorized as the Chlormadinone Acetate Reference Standard (Control 961) of National Institute of Health Sciences (Japanese Pharmacopoeia).

Chlormadinone Acetate↗
PubMed1997

[Hydrocortisone Acetate Reference Standard (Control 961) of National Institute of Health Sciences].

The raw material of hydrocortisone acetate was tested for the preparation of the "Hydrocortisone Acetate Reference Standard (Control 961)". Analytical data obtained were as follows: IR spectrum, specific absorption wave numbers at 3428, 1748, 1723, 1631, and 1375 cm-1; specific absorbance, E1cm1% (242 nm) = 406; thin-layer chromatography, no impurities were detected until 0.05 microgram; high-performance liquid chromatography (HPLC), 2-3 impurities were detected and the amount of the total impurities was estimated to be about 0.2%; assay by HPLC, 100.7%. Based on the above results, the raw material was authorized as the Japanese Pharmacopoeia Reference Standard (Control 961).

Hydrocortisone↗
PubMed1996

Synthesis and biological activity of conformationally restricted analogs of milnacipran: (1S,2R)-1-phenyl-2-[(S)-1-aminopropyl]-N,N-diethylcyclopropanecarboxami de, an efficient noncompetitive N-methyl-D-aspartic acid receptor antagonist.

We recently demonstrated that (+/-)-(Z)-2-(aminomethyl)-1-phenyl-N,N-diethylcyclopropanecarboxamide [milnacipran, (+/-)-1], an inhibitor of the reuptake of serotonin (5-HT), was a noncompetitive NMDA receptor antagonist. On the basis of the cyclopropane structure of (+/-)-1, conformationally restricted analogs with different stereochemistries, namely 1-phenyl-2-(1-aminoalkyl)-N,N-diethylcyclopropanecarboxamindes (2, 3, ent-2, and ent-3), were designed and synthesized. Among these analogs, 2a, 2b, and 2f, with (1S,2R,1'S)-configuration, were more efficient than milnacipran as NMDA receptor antagonists; these compounds significantly inhibited the binding of [3H]MK-801 at IC50 = 0.35 +/- 0.08, 0.20 +/- 0.024, and 0.16 +/- 0.02 microM, respectively, and blocked the response of voltage-clamped oocytes to NMDA, surpassing the effects of (+/-)-1. Although both the 1'-methyl analog 2a and the 1'-vinyl analog 2f, like (+/-)-1, strongly inhibited 5-HT uptake in vitro, the corresponding 1'-ethyl analog 2b was devoid of the inhibitory effect on 5-HT uptake, while it was about 30 times more potent as an NMDA receptor antagonist than (+/-)-1.

Animals↗
PubMed1996

Genetic basis of the neurovirulence of type 1 polioviruses isolated from vaccine-associated paralytic patients.

We examined four type 1 polioviruses isolated from the stools of patients with vaccine-associated paralytic poliomyelitis in China. All of these isolates were shown to be Sabin derived viruses by restriction fragment length polymorphism assay after polymerase chain reaction and by sequencing of the viral genome encoding the viral coat protein, VP1. However, the same analysis of the 3D coding region suggested that two of the four isolates had the sequence of wild type poliovirus in the tested region. Furthermore there were also point mutations in the 5' non-coding region. One was a single base change from U to C at nucleotide position 525, and the other three were from G to A at position 480. All the four strains were more neurovirulent that Sabin type 1 virus in transgenic mice with human poliovirus receptor gene. The data showed that the nucleotide positions of type 1 poliovirus which were identified to be in favor of the high neurovirulence were indeed changed during natural transmission, and suggested that the point mutation alone or a recombination of the vaccine type with wild type genome results in an acquisition of neurovirulence.

Animals↗
PubMed1996

Linear systems analysis of activating processes of complement system as a defense mechanism.

The complement system is an important element of the host defense mechanism, although its kinetics and characteristics as a system are still unclear. We have investigated its temporal changes and system properties from the view point of system engineering. The temporal changes of sequential activating processes of the system were expressed by 26 non-linear differential equations using reported values of rate constants and serum concentration for each component. The intermediate products in the activating processes increased parabolically while the membrane attack component as the final product, increased linearly. The little change in inactive precursors afforded validity for system linearization. Linear systems analysis revealed that the system which was insensitive to the changes in rate constants was unstable. The system became stable when the feed-back input from the final product was set to operate on the first step of the activating processes. Seven uncontrollable variables were insensitive to changes in rate constants or system optimization that minimized the changes in concentrations of components in the complement system. The singular values of the complement system were reduced and the impulse responses of the system were improved when the system was optimized. When stronger minimization was imposed on the changes of concentration of the components in the complement system, the singular values were reduced more, the magnitude of the impulse responses was depressed further and the responses terminated earlier than those when the elements in the weighting matrix of concentration of the components were set to be unity. By this potent minimization, the influences of changes in rate constants on the singular values were diminished. The present theoretical analysis is presented to evaluate the ability of defense mechanism of complement system.

Animals↗
PubMed1996

Circulation of type 1 wild poliovirus in northern Vietnam during 1991-1994.

From 1991 to 1994, 143 polioviruses were isolated from patients with acute flaccid paralysis in northern Vietnam. Of these 143 isolates, 133 were type 1 and five of each were type 2 and type 3. These isolates were intratypically differentiated by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Of the 133 type 1 isolates, 113 were wild strains and only 20 isolates were of Sabin vaccine-like strains. These 113 isolates were divided into seven groups by PCR-RFLP patterns and were also classified into three genomic groups by nucleotide sequencing and phylogenetic analysis. One of the three genomic groups accounted for the majority (75) of these isolates. The isolates belonging to the predominant group were found during 1991-1993. The second group, which included 17 isolates, were detected only in 1993. These isolates had genome sequence similar to isolates in southern Vietnam in the same year. The third group of isolates were detected only in 1991 and were considered to be Mahoney-like wild strains. All isolates examined were different from those obtained in other countries. In 1994, however, no wild-type polioviruses were isolated in our study. These results reveal that three unique strains were circulating in northern Vietnam in recent years, and indicate that the incidence of poliomyelitis due to wild poliovirus is decreasing.

DNA, Viral↗
PubMed1996

[Digitoxin Reference Standard (Control 951) of the National Institute of Health Sciences].

The raw material of digitoxin was tested for preparation of the "Digitoxin Reference Standard (Control 951)". Analytical data obtained were as follows: loss on drying, 0.0%; infrared spectrum, the same as that of the JP Digitoxin Reference Standard (Control 845); thin-layer chromatography, no impurity was detected; high-performance liquid chromatography (HPLC), two kinds of impurities were detected and the total amount was estimated to be 0.16 +/- 0.01% (n = 3); assay, 99.0% by HPLC. Based on the above results, the raw material was authorized as the JP Digitoxin Reference Standard (Control 951).

Chemical Phenomena↗
PubMed1996

[Betamethasone Reference Standard (Control 951) of the National Institute of Health Sciences].

The raw material of betamethasone was tested for preparation of the "Betamethasone Reference Standard (Control 951)". Analytical data obtained were as follows: loss on drying, 0.0%; infrared spectrum, the same as that of the JP Betamethasone Reference Standard (Control 845); thin-layer chromatography, no impurity was detected; high-performance liquid chromatography (HPLC), two kinds of impurities were detected and the total amount was estimated to be 0.16 +/- 0.01% (n = 3); assay, 100.0% by HPLC. Based on the above results, the raw material was authorized as the JP Betamethasone Reference Standard (Control 951).

Betamethasone↗
PubMed1996

[Tocopherol Acetate Reference Standard (Control 941) of the National Institute of Health Sciences].

The raw material of tocopherol acetate was tested for the preparation of the "Tocopherol Acetate Reference Standard (Control 941)". Analytical data obtained were as follows: infrared spectrum, the same as that of the Tocopherol Acetate Reference Standard (Control 919); specific absorbance, E1(1%)cm (284nm) = 44.5; thin-layer chromatography, no impurities were detected until 50.0 micrograms; high-performance liquid chromatography (HPLC), 2-3 impurities were detected and the amount was estimated to be about 1%; assay by HPLC, 100.8%. Based on the above results, the raw material was authorized as the Japanese Pharmacopoeia Reference Standard (Control 941).

Chemical Phenomena↗
PubMed1996

[Cyanocobalamin Reference Standard (Control 951) of the National Institute of Health Sciences].

The raw material of cyanocobalamin was tested for preparation of the "Cyanocobalamin Reference Standard (Control 951)". Analytical data obtained are as follows: loss on drying, 1.8%; infrared spectrum, the same as that of the JP Cyanocobalamin Reference Standard (Control 936); thin-layer chromatography, three impurities were detected; high-performance liquid chromatography (HPLC), eight to nine kinds of impurities were detected and the total amount of impurities was estimated to be 1.6 +/- 0.13% (n = 4); assay, 99.7% by spectrophotometry specified in the JP XII and 100.4% by HPLC, respectively. Based on the above results, the raw material was authorized as the JP Cyanocobalamin Reference Standard (Control 951).

Chemical Phenomena↗
PubMed1996

[Application of thermal analysis to quality evaluation tests of drugs].

Thermal analysis method can be applied to the quality evaluation tests of drugs. Recent advances in the technology and the data-processing system on the apparatus have accelerated the utilization of this analytical techniques in the field of drug quality control. In this report, various application techniques of the thermal analysis such as DSC, DTA, TG and the impurity analysis by DSC, were reported and discussed from the viewpoints of a general test in the Japanese Pharmacopoeia. Further the present situations of this analytical method in the US Pharmacopoeia 23 and the British Pharmacopoeia 1993 are also explained.

Differential Thermal Analysis↗