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Biomedical subjects

N Koda

Publications and source records attributed to N Koda.

At least 37 records · Page 2Linked to original sources

[Evaluation of hydroxyapatite implants in human periodontal osseous defects].

In this clinical study we evaluated the use of hydroxyapatite ceramic (HAP) implant in conjunction with the surgical treatment of periodontal osseous defects. Fifty-five defects in 23 patients were treated and filled with HAP particles (BDHAP-101). At 6 months and 12 months after the placement of particles, the sites were evaluated by gingival margin heights, periodontal pocket depths, attachment levels, tooth mobility, the gingival index (GI), and radiographic analyses. Oral hygiene status was estimated by the plaque index (PlI). There were significant improvements with regard to probe depth, attachment level, tooth mobility, and GI. The radiographic analysis showed a similar density of the adjacent bone and the particles, suggesting excellent biocompatibility. There were no changes in PlI before or after the placement of implants.

Bone Resorption↗

[Age-dependent changes in the phosphorylation of nuclear phosphoproteins of rat salivary glands].

Development, growth, maturation and aging processes of secretory cells of rat salivary glands progress mainly after birth. Nuclear non-histone proteins, phosphorylated actively and reversively, have an important role as regulatory molecules of gene activity and have a possibility to bring about specific changes in these cellular processes. We examined in the present study the age-dependent changes in the phosphorylation of non-histone proteins of rat salivary glands. Nuclei purified from submandibular and parotid glands of 8-week-old rats rapidly incorporated 32P from gamma-32P-ATP into the nuclear phosphoproteins and reached equilibrium within 9 min. A preponderant amount of the 32P was present in non-histone proteins. The levels of phosphorylation of non-histone proteins in salivary gland nuclei increased rapidly after birth, reaching a maximum in both gland nuclei of 4-week-old rats and then decreasing to the levels observed in submandibular and parotid gland nuclei from 20 and 16-week-old rats, respectively. These levels were still maintained in nuclei from aged rats. Moreover, age-dependent changes in the protein kinase activity of submandibular and parotid gland nuclei were linked up with the changes in the phosphorylation of non-histone proteins. However, changes were not observed in the phosphorylation of histone proteins after birth. These results suggest that protein kinase activity in salivary gland nuclei may have an important role on age-dependent changes in cell function, mediated through the control of the phosphorylation of non-histone proteins.

Aging↗

Immunological abnormalities in a patient with lysinuric protein intolerance.

We report an 8-year-old girl with lysinuric protein intolerance and immunological abnormalities including impaired function of lymphocytes, the presence of LE cells, antinuclear antibodies, and hypergammaglobulinaemia. These abnormalities have not been reported before and may be due to an amino acid imbalance or protein malnutrition in cells or tissues. The coincidence of a pre-stage of systemic lupus erythematosus (SLE) and LPI is not excluded.

Amino Acid Metabolism, Inborn Errors↗

Prevention of supersensitivity-like phenomena in rat vas deferens by colchicine.

Rat vas deferens has been shown to become supersensitive to alpha-adrenergic agonists on brief treatment with epinephrine (Epi-treatment). Epi-treatment increased the contractile response and the number of alpha-adrenoceptors in the tissue. The application of colchicine (2.5 mM) during Epi-treatment prevented the supersensitivity-like phenomena and increase in number of alpha-adrenoceptors. Vinblastine (10 microM) also counteracted the effect of Epi-treatment but cytochalasin B (100 microM) and strychnine (2.5 mM) did not. It is suggested that the supersensitivity-like phenomena induced in rat vas deferens by Epi-treatment were due to a change in microtubular components of the membrane.

Animals↗

Forskolin induces supersensitivity of the amylase secretory response of rat parotid tissue.

The stimulatory effect of forskolin on amylase secretion was studied by pretreating rat parotid tissue with forskolin for 10 min, incubating it in medium without forskolin for 10 min, and then treating it with forskolin again. Pretreatment with 10 microM forskolin for 10 min resulted in increased amylase secretion and enhanced accumulation of cyclic AMP in the tissue during the second incubation with forskolin. In the presence of colchicine or vinblastine, the enhancement in cyclic AMP accumulation during the second incubation with forskolin was prevented, but the increased amylase secretion remained unchanged. The increased amylase secretion was counteracted only in the presence of concanavalin A. On the other hand, increased amylase secretion induced by isoproterenol (IPR) pretreatment was counteracted by colchicine, vinblastine, concanavalin A or strychnine. These data suggest that the total amount of cyclic AMP in the tissue does not have any essential role in the supersensitivity of the amylase secretory response, and that the supersensitivity induced by forskolin differs from that induced by IPR.

Amylases↗

Effect of strychnine on the contractile response of rat vas deferens.

Strychnine at concentrations of 0.1 approximately 1.0 microM induced supersensitivity of rat vas deferens to alpha-agonists but not to other stimulants. Strychnine-treatment resulted in an increase in the number of alpha-adrenoceptors, determined by measuring the binding of [3H]prazosin. Glycine did not have any significant effect on the contracture and did not antagonize the action of strychnine. Thus, specific supersensitivity of alpha-adrenergic system was induced by treatment with low concentrations of strychnine.

Animals↗

[Laboratory and clinical studies on T-1982 (cefbuperazone) in the field of pediatrics].

T-1982 (cefbuperazone), a new 7 alpha-methoxycephem antibiotic, was fundamentally and clinically studied, and the following results were obtained. The antibacterial activities of T-1982 against clinical isolates of S. aureus, E. coli, K. pneumoniae, S. marcescens, P. mirabilis and P. aeruginosa were determined in comparison with those of CER, CEZ, CMZ and CTT. Against S. aureus, CER and CEZ exhibited excellent activity, whereas T-1982 was less active with the peak MIC of 12.5 micrograms/ml even with the inoculum size of 10(6) cells/ml. The activity of T-1982 was equal to that of CTT and by far superior to that of CER, CEZ and CMZ against E. coli, K. pneumoniae and P. mirabilis, the peak MICs with the inoculum size of 10(6) cells/ml being less than or equal to 0.1-0.2 microgram/ml, less than or equal to 0.1-0.2 microgram/ml and 0.2-0.39 microgram/ml, respectively. Against S. marcescens, T-1982 was superior to CMZ and CTT and 48% of the strains were inhibited by 3.13 micrograms/ml or less, whereas all the strains were resistant to CER and CEZ. The MIC of T-1982 against most strains of P. aeruginosa was more than 100 micrograms/ml. 10 mg/kg or 20 mg/kg of T-1982 was administered by one shot intravenous injection or 1 hour drip infusion to 23 pediatric patients to measure serum levels and urinary recovery. At 30 minutes after one shot injection of 10 mg/kg and 20 mg/kg, the highest serum levels of 22.0-38.8 micrograms/ml and 52.4-80 micrograms/ml were observed, the half-lives being 1.32 hours and 1.76 hours. When given by 1 hour drip infusion, the serum levels attained the peaks of 29.2-42.6 micrograms/ml and 49.0-75.6 micrograms/ml at the end of infusion, the half-lives being 1.24 hours and 1.19 hours. The urinary recovery rates within 6 hours were 74.2-92.5% and 50.2-66.5% by one shot injection and 63.4-84.2% and 53.9-79.0% by drip infusion. T-1982 was administered at a dose of 50 mg/kg by 30 minutes drip infusion to a child with purulent meningitis. The levels of T-1982 in the cerebrospinal fluid at 1 hour after administration were 4.8-6.7 micrograms/ml with the CSF/serum ratios of 4.4-8.4%. A total of 36 pediatric patients (21 cases of respiratory tract infection, 9 cases of urinary tract infection and each 1 case of purulent cervical lymphadenitis, scarlet fever, purulent meningitis, acute colitis, peritonitis and sinusitis) was treated with 40-80 mg/kg/day of T-1982 (252.6 mg/kg/day in purulent meningitis). The response was excellent in 27 patients and good in 7 patients, the efficacy rate being 94.4%. Diarrhea or eruption were observed in each 1 case. No abnormal laboratory findings were noted in any cases.

Adolescent↗

Prenatal diagnosis of metachromatic leukodystrophy: a diagnosis by amniotic fluid and its confirmation.

Late infantile metachromatic leukodystrophy (MLD) was successfully diagnosed in utero by demonstrating the absence of arylsulfatase-A in amniotic fluid using diethylaminoethyl-Sepharose column chromatography. Diagnosis by amniotic fluid using an ion-exchange column is more rapid and reproducible as compared with those reported previously. The diagnosis was confirmed by the absence of arylsulfatase-A in fetal brain, liver, and kidney tissues as well as by the marked accumulation of sulfatide in kidney. The kidney is the most appropriate organ for the demonstration of sulfatide accumulation in fetal tissues in MLD.

Amniotic Fluid↗