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Biomedical subjects

K Atsumi

Publications and source records attributed to K Atsumi.

At least 19 recordsLinked to original sources
PubMed1993

Pharmacokinetic properties of recombinant feline interferon and its stimulatory effect on 2',5'-oligoadenylate synthetase activity in the cat.

The pharmacokinetic behavior of recombinant feline interferon produced in silkworm infected with recombinant baculovirus harboring cDNA coding for feline interferon was studied in vivo in cats. The decreasing profile of the serum interferon level after intravenous administration was fitted to a two-compartment model. The half-times of the first phase (distribution phase) and second phase (metabolic phase) were 5.0 +/- 0.5 min and 31 +/- 5 min, respectively. In the whole body autoradiogram, at 15 min after the administration, the highest radioactivity was observed in urine in the bladder, and predominant radioactivity in the kidneys, liver, thyroid gland and spleen. Almost no radioactivity was detected in the brain or fat. Three hr after administration, the highest radioactivity was recorded in the thyroid gland, urine in the bladder, intestinal contents, and gastric mucous membrane. The data obtained in this study suggest that recombinant feline interferon has similar pharmacokinetic properties to human interferons and that it is distributed primarily in the liver and kidneys, is catabolized rapidly mainly in the kidneys, and is excreted in the urine without residual accumulation in the body. It was confirmed that 2',5'-oligoadenylate synthetase activity was increased by the interferon in vivo for 3 days after an intravenous bolus injection in cats.

2',5'-Oligoadenylate Synthetase↗
PubMed1991

Synthesis and oral activity of pivaloyloxymethyl 7-[(Z)-2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido]-3(Z)- (4-methylthiazol-5-yl)vinyl-3-cephem-4-carboxylate (ME1207) and its related compound.

7-[2-(2-Aminothiazol-4-yl)-2(Z)-methoxyiminoacetamido]-3(Z)- (4-methylthiazol-5-yl)vinyl-3-cephem-4-carboxylic acid (11, ME1206) and its 3-trans isomer (13) were prepared to test antibacterial activity. These compounds exhibited excellent antibacterial activity against both gram-positive and gram-negative bacteria, including beta-lactamase producing strains. The pivaloyloxymethyl esters (12 and 14) of the compounds (11 and 13) were prepared by esterification with pivaloyloxymethyl iodide. Among them, pivaloyloxymethyl 7-[(Z)-2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido]- 3(Z)-(4-methylthiazol-5-yl)vinyl-3-cephem-4-carboxylate (12, ME1207) showed good urinary recovery after oral administration in mice.

Administration, Oral↗
PubMed1990

Synthetic cephalosporins. VI. Synthesis and antibacterial activity of 7-[(Z)-2-(2-aminothiazol-4-yl)-2-(1-carboxy-1-methyl) ethoxyiminoacetamido]- 3-(3-hydroxy-4-pyridon-1-yl)methyl-3-cephem-4-carboxylic acid and related compounds.

Synthesis and antibacterial activity of 7-[(Z)-2-(2-aminothiazol-4-yl)-2-(1-carboxy-1-methyl)ethoxyimin oacetamido]- 3-(3-hydroxy-4-pyridon-1-yl)-3-cephem-4-carboxylic acid (12) and its related compounds are described. Compound 12 exhibited excellent antibacterial activity against gram-negative bacteria, and its anti-pseudomonal activity was ten to fifteen times greater than that of ceftazidime.

Cephalosporins↗
PubMed1990

Synthetic cephalosporins. VII. Synthesis and antibacterial activity of 7-[(Z)-2-(2-aminothiazol-4-yl)-2-(3-(3-hydroxy-4-pyridon-1-yl)-3- carboxypropoxyimino)acetamido]-3-(1,2,3-thiadiazol-5-yl)-thiomethyl-3- cephem-4-carboxylic acid and its related compounds.

Synthesis and antibacterial activity of 7-[(Z)-2-(2-aminothiazol-4-yl)-2-(3-(3-hydroxy-4-pyridon-1-y l)-3- carboxypropoxyimino)acetamido]-3-(1,2,3-thiadiazol-5-yl)thio methyl-3-cephem-4-carboxylic acid (12a) and its related compounds are described. Compound 12a exhibited excellent antibacterial activity against gram-negative bacteria, including Pseudomonas aeruginosa.

Bacteria↗
PubMed1990

A new antipseudomonal cephalosporin CP6162 and its congeners.

The synthesis and biological activity of a series of 3-[2-(5-hydroxy-4-pyridon-2-yl)ethenyl]cephalosporin derivatives are described. They showed very potent activity against Gram-negative bacteria, especially Pseudomonas aeruginosa. (6R, 7R)-7-[(Z)-2-(2-Aminothiazol-4-yl)-2 -(1-carboxy-1-methyl)-ethoxyiminoacetamido]-3-[(Z)-2-(1,5-dihydrox y-4- pyridon-2-yl)ethenyl]ceph-3-em-4-carboxylic acid, CP6162 (8e), was selected for further evaluation as antipseudomonal chemotherapeutic agent.

Animals↗
PubMed1989

[Synthetic cephalosporins. III. Synthesis and antibacterial activity of 7-[2-(2-Aminothiazol-4-yl)-3-carboxy-2-propenoamido]cep hal osporins and related compounds].

Synthesis and antibacterial activity of 7-[2-(2-aminothiazol-4-yl)-3-carboxy-2-propenoamido]cepha los porins and their derivatives are described. These compounds are of interest as carbon analogues of oximecephalosporins, 7-[2-(2-aminothiazol-4-yl)-2(Z)-oxyiminoacetamido]cephalo spo rins having remarkable antibacterial activity. The synthesized 7-[2-(2-aminothiazol-4-yl)-3(Z)-carboxy-2-propenoamido]-c eph alosporins (14, 19) show improved activity especially against the beta-lactamase-producing strains. A 7-[2-(2-aminothiazol-4-yl) maleimido]cephalosporin (15) has been also prepared by cyclization of 7-[3-(2-aminothiazol-4-yl)-2-ethoxycarbonyl-2(Z)-propenoamido++ +]cephalosporin.

Bacteria↗
PubMed1989

[Automatic control of total artificial heart to simulate the hemodynamics under natural heart circulation].

We developed control system of total artificial heart (TAH) during exercise simulating the circulatory response of natural heart. The following procedures were taken to develop this system. 1) Measurement of hemodynamics and physical activity rate (PAR) of natural heart goats during treadmill exercise. 2) Estimation of cardiac output from PAR using a non-linear model. 3) Development of a pneumatic artificial heart (AH) driver with high speed controllability and a control unit to deliver CO calculated from PAR beat by beat. 4) Evaluation of the physiological condition of the TAH goat during exercise controlled by this system. Using this control method, CO of TAH goats was similar to that of natural heart goats during treadmill exercise. Hypertension was observed during exercise. This hypertension was considered to be derived from two causes. One was high inflow and outflow resistance of cannulae between AH pump and living body. The other was the disorder of peripheral circulatory control mechanism in TAH animal. Such as increased sympathetic activity, insufficient secretion of atrial natriuretic polypeptide (ANP) and decreased sensitivity of peripheral circulatory system with ANP.

Animals↗
PubMed1987

Research and development on total artificial heart in University of Tokyo.

The research and development on the total artificial heart (TAH) in the University of Tokyo can be divided chronologically into the three stages, i.e., the first stage (1959-1970); trial and error stage to find appropriate hardwares, the second stage (1970-1985); software stage to find how to control pneumatic TAH and to manage the animals, and the third stage (1985- ); final goal to develop implantable TAH for animal and human. This paper reviews the process of research and development in each stage.

Animals↗
PubMed1986

Chitin is an effective material for sutures.

Chitin is an absorbable suture material with suitable mechanical properties. Tissue reaction is not specific and the good healing which ensued provided evidence for a satisfactory biocompatibility. Toxicity tests, including acute toxicity, pyrogenicity, mutagenicity were negative in all respects. The chitin suture was absorbed in about four months in rat muscles. The persistence of the tensile strength of the chitin was better than Dexon (TM) or catgut in bile, urine and pancreatic juice but weakening occurred early in the presence of gastric juice. Application in 132 patients proved satisfactory. Adverse effects were nil.

Adolescent↗
PubMed1986

Experimental studies of photo radiation therapy on neuroblastoma.

A combination of Photo Radiation Therapy (PRT) using Argon-Dye Laser with hematoporphyrin derivatives (HpD) was used experimentally on a cytogenetically highly malignant neuroblastoma xenograft, which exhibited a homogeneously staining region and caused DNA amplifications in chromosomes. The tumor tissue was treated with 500 joules/cm2 of laser. The dosage of HpD was 50 mg per kg body weight. Necrosis of over 50% of the tumor was observed in half the specimens. Swollen cytoplasmic organelles and ruptured cell and nuclear membranes were observed by electron microscopy after PRT. PRT may be used with other treatment modalities for the removal of residual and metastatic tumors.

Animals↗