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Biomedical subjects

M Takagi

Publications and source records attributed to M Takagi.

At least 901 records · Page 50Linked to original sources

[Laboratory and clinical studies of 9,3"-diacetylmidecamycin in the pediatric field].

The authors have carried out laboratory and clinical studies of 9,3"-diacetylmidecamycin (MOM) and obtained the following results. 1. Absorption and excretion of MOM. MOM was administered orally to 4 patients at a dose of 10 mg/kg in the fasting condition. The peak of serum levels was found at 30 minutes after administration. The mean values were 1.3 +/- 0.5 microgram/ml, and 1.1 +/- 0.9 microgram/ml after 30 minutes and 1 hour respectively. The serum levels were detectable in 2 cases after 2 hours (1.0 and 0.78 microgram/ml), in 1 case after 4 hours (0.78 microgram/ml) and were not detectable in all cases after 6 hours. Half-life was able to calculate in 2 cases (2.5 and 1.5 hours). The mean urinary recovery rate examined in 3 cases was 0.33% for initial 6 hours. 2. Clinical result. MOM was administered to 35 children at a daily dose of 16.7--51.1 mg/kg divided into 3 or 4 doses for 4 to 19 days: 18 cases with bacterial infection (9 cases with tonsillitis, 7 cases with scarlet fever and each 1 case with bronchitis and pneumonia) and 17 cases with Mycoplasma infection (5 cases with bronchitis and 12 cases with pneumonia). The overall clinical response was good in 28 cases (80.0%), fair in 6 cases and poor in 1 case. The efficacy rate in bacterial infections and Mycoplasma infections were 66.7 and 94.1% respectively. Eight strains of S. pyogenes and 1 strain of S. pneumoniae were isolated from 9 cases. One strain of S. pyrogenes was eradicated and the others were unchanged. The eradication rate was 11.1%. The MIC of MOM against S. pyogenes was above 50 micrograms/ml in 3 strains out of measured 5 isolated strains. 3. Side effect. Side effects were examined with all the 54 cases involving 19 drop-out cases. Although clinical side effects were not observed, a mild elevation in GOT and a mild rise in eosinophil were observed in 2 cases and 1 case respectively.

Adolescent↗

Ultrastructural localization of lactoferrin and iron-binding protein in human neutrophils and rabbit heterophils.

Lactoferrin in marrow and blood granulocytes from rabbits and humans was stained with an immunoferritin method. Iron-binding protein(s) was localized by the staining of granulocytes with acid ferrocyanide after saturation of the iron-binding protein with iron. The latter was most readily accomplished by treatment of the glutaraldehyde-fixed cell suspension with 1% saponin, followed by treatment with an iron-nitrilotriacetate (Fe-NTA 3mM:4mM) solution, adjusted to pH 7.0 with NaHCO3. The affinity of purified lactoferrin and transferrin for radioiron after such treatment was minimally diminished. Both immunoferritin and iron-binding methods heavily stained osmiophiliuc (phospholipid-containing) mature primary granules in late promyelocytes, myelocytes, and polymorphonuclear cells. Early promyelocytes containing abundant immature primary granules lacked immunoferritin or iron staining. Trypsin digestion of rabbit marrow cells considerably diminished the cytochemically demonstrable iron-binding capability of the mature primary granules. Specimens sequentially stained for peroxidase and immunostained for lactoferrin or cytochemically stained for iron-binding protein confirmed that lactoferrin and iron-binding protein were in peroxidase-positive primary granules. Some peroxidase positive granules appeared to lack staining for lactoferrin and iron-binding proteining protein, and all secondary granules uniformly lacked staining. Treatment of human neutrophils with phorbol myristate acetate demonstrated early release of granules containing iron-binding protein with subsequent agglutination of neutrophils and attachment of iron-binding protein to the cell surface. In summary, this study distinguishes at least two subpopulations of primary granules and identifies lactoferrin and an iron-binding protein(s) in a subpopulation of peroxidase-positive primary granules in rabbit heterophils and human neutrophils.

Animals↗

Function of the phosphate group of pyridoxal 5'-phosphate in the glycogen phosphorylase reaction.

To understand the catalytic mechanism of glycogen phosphorylase (EC 2.4.1.1), pyridoxal(5')phospho(1)-beta-D-glucose was synthesized and examined as a hypothetical intermediate in the catalysis. Pyridoxal phosphoglucose bound stoichiometrically to the cofactor site of rabbit muscle phosphorylase b in a similar mode of binding to the natural cofactor, pyridoxal 5'-phosphate. The rate of binding of pyridoxal phosphoglucose was only 1/100 compared with that of pyridoxal phosphate. The enzyme reconstituted with pyridoxal phosphoglucose showed no enzymatic activity at all even after prolonged incubation of the enzyme with substrates and activator. The present data would contradict participation of the phosphate group of pyridoxal phosphate in a covalent glucosyl-enzyme intermediate even if the covalent intermediate was formed during the catalysis.

Animals↗

Doublet-outlet right ventricle [S,D,L] with subaortic ventricular septal defect and pulmonary stenosis: successful repair using an intraventricular conduit.

An 18-year-old Japanese girl with double-outlet right ventricle (DORV) [S,D,L], subaortic ventricular septal defect and pulmonary stenosis was successfully treated under cardiopulmonary bypass by resection of the obstructing subpulmonic infundibulum, pulmonary valvulotomy and construction of an intraventricular conduit between the ventricular septal defect and the aorta. The postoperative course was uneventful, except for mild low-output syndrome, and she was discharged 7 weeks after surgery in good condition. She is at present free from all untoward cardiac symptoms.

Adolescent↗

Proton translocation coupled to trimethylamine N-oxide reduction in anaerobically grown Escherichia coli.

Proton translocation coupled to trimethylamine N-oxide reduction was studied in Escherichia coli grown anaerobically in the presence of trimethylamine N-oxide. Rapid acidification of the medium was observed when trimethylamine N-oxide was added to anaerobic cell suspensions of E. coli K-10. Acidification was sensitive to the proton conductor 3,5-di-tert-butyl-4-hydroxybenzylidenemalononitrile (SF6847). No pH change was shown in a strain deficient in trimethylamine N-oxide reductase activity. The apparent H+/trimethylamine N-oxide ratio in cells oxidizing endogenous substrates was 3 to 4 g-ions of H+ translocated per mol of trimethylamine N-oxide added. The addition of trimethylamine N-oxide and formate to ethylenediaminetetraacetic acid-treated cell suspension caused fluorescence quenching of 3,3'-dipropylthiacarbocyanine [diS-C3-(5)], indicating the generation of membrane potential. These results indicate that the reduction of trimethylamine N-oxide in E. coli is catalyzed by an anaerobic electron transfer system, resulting in formation of a proton motive force. Trimethylamine N-oxide reductase activity and proton extrusion were also examined in chlorate-resistant mutants. Reduction of trimethylamine N-oxide occurred in chlC, chlG, and chlE mutants, whereas chlA, chlB, and chlD mutants, which are deficient in the molybdenum cofactor, could not reduce it. Protons were extruded in chlC and chlG mutants, but not in chlA, chlB, and chlD mutants. Trimethylamine N-oxide reductase activity in a chlD mutant was restored to the wild-type level by the addition of 100 microM molybdate to the growth medium, indicating that the same molybdenum cofactor as used by nitrate reductase is required for the trimethylamine N-oxide reductase system.

Anaerobiosis↗

Ultrastructural localization of complex carbohydrates in odontoblasts, predentin, and dentin.

Glycosaminoglycans (GAGs) and glycoproteins (GPs) are essential components for dentinogenesis. We have examined rat odontoblasts, predentin, and dentin decalcified with EDTA and stained with: 1) Spicer's hig-iron diamine-thiocarbohydrazide-silver proteinate (HID-TCH-SP) method for sulfated glycoconjugates, and 2) Thiéry's periodate-thiocarbohydrazide-silver proteinate (PA-TCH-SP) method for vicinal glycol-containing glycoconjugates. HIS-TCH-SP stained distended portions of Golgi saccules and secretory granules. The predentin contained three times the number of HID-TCH-SP stain precipitates when compared to the mineralization front of the dentin matrix. PA-TCH-SP weakly stained membranes of Golgi saccules and cisternae of rough endoplasmic reticulum (RER), whereas stronger staining was observed in secretory granules, lysosomes, and multivesicular bodies (MVBs). Collagen fibrils in predentin demonstrated moderate PA-TCH-SP staining. In contrast, strong PA-TCH-SP staining was observed on and between collagen fibrils in the mineralization front of the dentin matrix. TCH-SP controls of unosmicated specimens lacked significant staining, however, osmicated control specimens did contain some TCH-SP stain deposits in the mineralization front. These results indicate that sulfated and vicinal glycol-containing glycoconjugates are packaged in the same type of secretory granule and released into the extracellular matrix; subsequently vicinal glycol-containing glycoconjugates concentrate in the calcification front, whereas sulfated glycoconjugates accumulate in the predentin and are either removed or masked to staining in the dentin.

Animals↗

Counter measures against death from arrhythmias in acute myocardial infarction: mortality of the disease in a hospital at different periods with changing care systems. Factors of delay in the pre-hospital phase.

The results of treatment of 400 patients with established acute myocardial infarction in a hospital at different periods with changing care systems are described. Significant reduction of death from arrhythmias could be obtained only when an organization with immediate availability of well-trained medical personnel and reliable actual continuous monitoring of electrocardiograms had been established. Components of delay in the pre-hospital phase of acute myocardial infarction were also studied. There were two significant factors in delay: one was delay due to ignorance of patients about the disease, second was the delay after consultation of family doctors until arrival at the CCU. Time is consumed in the latter factor mainly in making of definite diagnosis. The implication of these data in the management of patients with a diagnosis of acute myocardial infarction are discussed.

Arrhythmias, Cardiac↗