Search PubMed⌕ Search

Biomedical subjects

M Takagi

Publications and source records attributed to M Takagi.

At least 811 records · Page 45Linked to original sources
PubMed1985

[Laboratory and clinical studies of BRL 25000 (clavulanic acid-amoxicillin) granules in the pediatric field].

The authors have carried out laboratory and clinical studies on the BRL 25000 granule (containing 2 parts amoxicillin and 1 part clavulanic acid). The antibacterial activity of BRL 25000 against 29 clinically isolated strains of S. aureus, 30 E. coli and 30 K. pneumoniae were measured by the agar dilution method using an inoculum size of 10(6) cells/ml. beta-Lactamase production was detected by the Nitrocefin method. The MICs of BRL 25000 against S. aureus ranged from 0.2 approximately 12.5 micrograms/ml, with the majority of strains being inhibited by 1.56 micrograms/ml or less. Seven beta-lactamase producing strains of S. aureus were all inhibited by less than 12.5 micrograms/ml. The range against E. coli was 1.56 approximately 100 micrograms/ml, with the majority inhibited by 6.25 micrograms/ml or less. Fifteen beta-lactamase producing strains of E. coli were inhibited by 6.25 approximately 100 micrograms/ml and the majority by 25 micrograms/ml or less. All strains of K. pneumoniae were beta-lactamase producers and the MIC distribution against K. pneumoniae was 1.56 approximately 50 micrograms/ml, with a majority inhibited by 3.13 micrograms/ml or less, 96% of strains, were inhibited by less than 6.25 micrograms/ml. Against K. pneumoniae, BRL 25000 showed a 8 to 16-fold superiority when compared with AMPC. In a pharmacokinetic study, BRL 25000 granules were orally administered to children in the fasting state at single doses of 7.5 mg/kg and 20 mg/kg. The peak serum levels of AMPC were 6.13 and 6.94 micrograms/ml approximately 1 hour after administration and decreased with half-lives of 1.08 and 0.97 hours, respectively. The corresponding serum levels of CVA were 1.16 and 1.90 micrograms/ml at 1 hour after administration, with half-lives of 0.99 and 0.87 hour, respectively. In clinical studies, the BRL 25000 granule was effective in 39 cases of bacterial infection out of a total of 41 treated. Side effects were limited to 2 cases of diarrhea and minor changes in laboratory findings were elevation of serum GOT (1 case), elevation of serum GPT (1 case), and eosinophilia (2 cases).

Administration, Oral↗
PubMed1985

[Laboratory and clinical studies of aztreonam in the pediatric field].

The authors have carried out the laboratory and clinical studies of aztreonam (AZT) and obtained the following results. The antibacterial activities of AZT against the clinical isolates of E. coli, K. pneumoniae and P. aeruginosa were measured by the agar dilution method with inoculum size of 10(6) cells/ml. The susceptibility distribution of E. coli to AZT ranged from 0.025 or lower to 1.56 microgram/ml, and the peak of distribution was 0.05 microgram/ml. The peak of susceptibility distribution of K. pneumoniae was 0.025 microgram/ml or lower, and the distribution of P. aeruginosa ranged from 0.1 to 100 micrograms/ml higher and the peak of distribution was 3.13 micrograms/ml. After intravenous bolus injection of 20 mg of AZT in 4 children, the mean peak serum level was 117 +/- 35.1 micrograms/ml at 15 minutes after injection, and half-life time was 1.42 hours. The mean urinary excretion rates was 63.2 +/- 30.6% up to 6 hours after bolus injection of 20 mg/kg of AZT. AZT was given 11 cases with bacterial injection. Daily doses of AZT were from 41.7 to 94.9 mg/kg. Clinical results obtained were excellent and good responses in 8 of 11 cases (72.7%). No side effect was observed.

Age Factors↗
PubMed1984

Ultrastructural cytochemistry of proteoglycans associated with calcification of shark cartilage.

Proteoglycans (PGs) as well as sulfated glycosaminoglycans (GAGs) are closely associated with cartilage calcification. An inner zone of endoskeletal tesserae of sharks is composed of a unique calcified hyaline cartilage. Initial calcification can be seen in the cartilage close to the inner zone. We have ultrastructurally examined shark, Triakis scyllia, noncalcifying, calcifying, and calcified cartilage using the tannic acid-ferric chloride (TA-Fe), the high iron diamine (HID), and the HID-thiocarbohydrazide-silver proteinate (HID-TCH-SP) methods for localization of sulfated complex carbohydrates. In noncalcifying cartilage, TA-Fe and HID strongly stained matrix granules which were round, ovoid, elongated, or irregularly shaped and presumably represented PG monomers. The size and staining intensity of the reactive matrix granules progressively decreased in calcifying cartilage toward the calcification front of the calcified cartilage. Similarly, a progressive decrease in the size of the HID-TCH-SP stain deposits in the matrix granules was observed in the calcifying cartilage close to the calcification front and was interpreted as a decrease in length of sulfate containing GAG chains. In the calcified cartilage, the highly calcified areas were often localized in the calcification front and contained few or no small HID-TCH-SP stain deposits, whereas the weakly calcified regions contained more stain deposits. These results indicate that partial and complete degradation of sulfated GAGs and/or PGs may be a requisite for calcification of shark cartilage.

Animals↗
PubMed1984

Ultrastructural localization of glycosaminoglycans in human term placenta.

Sulfated glycoconjugates were stained in normal human term placentas using Spicer's high-iron diamine (HID) method with thiocarbohydrazide and silver proteinate (TCH-SP) enhancement. Specific identification of glycosaminoglycans (GAG) was accomplished by digestion of the stained material with chondroitinase ABC or AC for removal of chondroitin sulfates and nitrous acid for removal of N-sulfated GAGs. The syncytiotrophoblast apical surface demonstrated moderate to intense staining with HID-TCH-SP, which was removed by prior digestion with the chondroitinases, but not by nitrous acid. The syncytiotrophoblast basal surface and endothelial cell surfaces lacked sulfate staining. A few cytoplasmic granules in syncytiotrophoblast cells demonstrated staining similar to the apical surface. Three layers of the basal lamina were identified in these preparations. The lamina lucida immediately beneath the syncytiotrophoblast and the majority of the lamina densa stained weakly or not at all, whereas the underlying lamina diffusa and stroma demonstrated moderate to intense staining. The majority of lamina diffusa staining was removed by chondroitinase ABC or AC; the remaining material was removed by nitrous acid digestion. Thus the syncytiotrophoblast surface contains a chondroitin sulfate and the basal lamina contains a mixture of intensely stained chondroitin sulfate and a weakly stained N-sulfated GAG.

Connective Tissue↗
PubMed1984

Actions of cholinergic drugs on cells in the interpeduncular nucleus.

The muscarinic versus nicotinic effects of acetylcholine (ACh) on the activity of cells in the interpeduncular nucleus (IPN) of guinea pig brain slices were investigated using electrophysiologic techniques. Nicotinic and muscarinic drugs acted postsynaptically to increase the firing rate of cells in the IPN. The excitatory actions of ACh were blocked both by atropine and by d-tubocurarine. These results indicated that cholinergic receptors of IPN cells seem to have both nicotinic and muscarinic characteristics.

Acetylcholine↗
PubMed1984

The presence of Angiostrongylus cantonensis in Viti Levu, Fiji.

Wild rats and molluscs were examined for Angiostrongylus cantonensis infection on Viti Levu, Fiji. A. cantonensis were recovered from 29.6% (16/54) of Rattus rattus and 59.5% (25/42) of R. exulans. A. cantonensis-like larval nematodes were found in all of four slugs, Laevicaulis alte, and ten of 20 unidentified land snails. The larvae developed to adult A. cantonensis in the pulmonary arteries of laboratory rats 40 to 42 days after ingestion. This is the first record of A. cantonensis in Fiji.

Angiostrongylus↗
PubMed1984

Ultrastructure of cartilaginous tumors and S-100 protein in the tumors. With reference to the histogenesis of chondroblastoma, chondromyxoid fibroma and mesenchymal chondrosarcoma.

Twelve cartilaginous tumors were studied by electron microscopy and the presence of S-100 protein was studied immunohistochemically in order to clarify the cell origin of chondroblastoma, chondromyxoid fibroma, and mesenchymal chondrosarcoma. Three chondroblastomas were characterized by round or ovoid tumor cells with some cytoplasmic processes, well-developed organelles and thick fibrous laminae in the nuclear membrane, occasional multinucleated giant cells and scanty chondroid matrix. S-100 protein was demonstrated in the tumor cells and some multinucleated giant cells Two chondromyxoid fibromas revealed tumor cells of varied shapes with characteristic cartilaginous differentiation and abundant chondroid matrix. Spindle tumor cells showed the ultrastructural features of cartilage cells rather than of fibroblasts and S-100 protein was also demonstrated in their cytoplasm. Chondroblastoma and chondromyxoid fibroma were considered to arise from chondrocytes. Mesenchymal chondrosarcoma ultrastructurally exhibited round tumor cells with cartilaginous nature in cartilage islands. Poorly-differentiated portions were composed of primitive round or elongated cells with occasionally admixed round cells with ultrastructural features of cartilaginous differentiation. S-100 protein was demonstrated in the cells in cartilage islands and in single cells admixed in poorly-differentiated portions. These results support the hypothesis of primitive mesenchymal origin with a tendency to differentiate toward cartilage cells.

Cartilage↗
PubMed1984

Scanning electron microscopic and X-ray microdiffractometeric studies on sialolith-crystals in human submandibular glands.

The crystalline structures of 18 submandibular gland calculi were studied by radiomicrography , scanning electron microscope, and X-ray microdiffractometeric techniques. The following observations were made by SEM: Granular or globular structure was seen on the surface of all cases and pyramidal crystal in one case. In the inside, all showed lamellar pattern with amorphous nucleus in the center, and granular, plate-like and rhombohedral structures were also observed. X-ray microdiffractometeric analyses: Apatite was frequently observed in both outside and inside of the calculi. Whitlockite was next frequently detected and was seen more often in the inside. Brushite and weddellite were noted in the outside of calculi in one case each. Thus, it is suggested that brushite and weddellite were present in the front portion of calculus formation and then transformed into the more stable form e.g. apatite.

Apatites↗
PubMed1984

Ultrastructural and immunohistochemical characteristics of cardiac myxoma.

Ultrastructural and immunohistochemical studies of six cardiac myxomas were carried out to further elucidate the histogenesis of this tumor and the cell character of myxoma cell. Ultrastructurally myxoma cells have varying degrees of endothelial characteristics with prominent vasoformative activity. Immunohistochemically, blood group H-antigen and Factor VIII-related antigen were identified in tumor cells of all six cases. Prostaglandin I2 was demonstrated in five. The contractile proteins (actin and myosin), basement membrane components (laminin and fibronectin) were identified in all cases. Intermediate filament vimentin was demonstrated in two cases. On the other hand, desmin, keratin, and glial fibrillary acidic protein were not demonstrated. This result further supports the concept of the endothelial origin of cardiac myxoma rather than origin form multipotential mesenchymal cells. Myxoma cells infiltrated and covered the fibrin thrombi attached to the surface of the tumor, and the fibrin thrombi were replaced by myxoid matrix as the myxoma cells infiltrated it. This finding suggests that fibrin thrombi may be related to the growth of cardiac myxoma and active synthesis of prostaglandin I2 in myxoma cells may be due to intimate contact with platelet-rich fibrin thrombi attached to the tumor.

Adolescent↗
PubMed1984

Ultrastructural and histochemical studies of granular-cell ameloblastoma.

Four cases of granular-cell ameloblastoma were studied by light and electron microscopy, histochemistry and electron enzyme histochemistry. Microscopically, granular cells commonly occurred in a follicular pattern, but, in one case, they were in a plexiform pattern. The high activity of acid phosphatase and electron microscopic features revealed that the cytoplasmic granularity was ascribed to the high content of lysosomes. It was speculated that granular-cell ameloblastoma occurs due to the altered dysfunction of tumor cells, and the age factor is related to the pathogenesis of this tumor.

Acid Phosphatase↗
PubMed1984

Ultrastructural cytochemistry of oxytalan fibers in the periodontal ligament and microfibrils in the aorta with the periodic acid-thiocarbohydrazide-silver proteinate method.

Fullmer's oxytalan fibers are special connective tissue fibers in periodontal ligaments and some non-dental sites of certain animal species, and, ultrastructurally appear to resemble microfibrils related to elastogenesis. The present study has ultrastructurally examined the applicability of Thiéry's periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) method for vicinal glycol-containing complex carbohydrates to the study of oxytalan fibers in rat periodontal ligaments and microfibrils of the tunica adventitia in the rat aorta, where microfibrils are often associated with amorphous elastin and are thought to be oxytalan fibers. In the periodontal ligaments, the PA-TCH-SP method weakly to moderately stained collagen fibrils, moderately stained thin fibrils composing the oxytalan fibers, and intensely stained cytoplasmic granules of fibroblasts. In the aortic adventitia, the PA-TCH-SP method moderately stained collagen fibrils. Heavier staining was observed in microfibrils, whereas the amorphous elastin lacked staining. The most intense staining was seen in cytoplasmic granules and glycogen of mural cells. These studies demonstrate that oxytalan fibers in the periodontal ligament of rats and microfibrils in the aorta of rats contain vicinal glycol-containing glycoproteins and the PA-TCH-SP method is a useful tool in ultrastructural studies of oxytalan fibers and microfibrils of rats.

Animals↗
PubMed1984

Gene responsible for protecting Escherichia coli from sodium dodecyl sulfate and toluidine blue plus light.

Escherichia coli cells were killed by visible light irradiation in the presence of the photosensitizing dye, toluidine blue. Two uvrB mutant strains of E. coli K-12 (AB1885 and N3-1) were much more sensitive than the isogenic uvrA and uvrC strains to treatment with toluidine blue plus light, suggesting that the uvrB+ gene product was involved in repair of DNA damage induced by the treatment. The uvrB+ gene cloned in a high- or low-copy-number plasmid was transformed into the uvrB strain (AB1885). Although all the transformants showed the same resistance as its wild-type strain (AB1157) to UV irradiation, they were as sensitive as AB1885 was to treatment with toluidine blue plus light. The two uvrB strains were more sensitive to sodium dodecyl sulfate than the other strains, suggesting that these strains had a defect in the cell surface. A sodium dodecyl sulfate-resistant revertant obtained from AB1885 was more resistant than AB1885 was to treatment with toluidine blue plus light. The two uvrB strains (AB1885 and N3-1) appear to have a defective gene (tentatively called dvl) different from uvrB. Its map position was around 7 min on the E. coli map.

Base Sequence↗
PubMed1984

Relaxation of supercoiled plasmid DNA by oxidative stresses in Escherichia coli.

The relaxation of plasmid DNA was observed after the visible light irradiation of Escherichia coli AB1157 harboring plasmid pBR322 or some other plasmids in the presence of a photosensitizing dye, such as toluidine blue or acridine orange, and molecular oxygen. Treatment of the cells with hydroperoxides, such as tert-butyl hydroperoxide, cumene hydroperoxide, and hydrogen peroxide, also caused the plasmid DNA relaxation in vivo. Relaxation was not observed in these treatments of purified pBR322 DNA in vitro. Plasmid DNA relaxation was also detected after near-UV irradiation. Far-UV irradiation did not induce such relaxation.

DNA, Superhelical↗