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Biomedical subjects

N Kikuchi

Publications and source records attributed to N Kikuchi.

At least 91 records · Page 5Linked to original sources
PubMed1995

Vascular smooth muscle cell-derived, Gla-containing growth-potentiating factor for Ca(2+)-mobilizing growth factors.

Proliferation of vascular smooth muscle cells (VSMC) is triggered by two types of growth factors. One activates tyrosine kinase-type receptors and the other activates G-protein-coupled receptors. We found that a conditioned medium of rat VSMC contained a growth-potentiating activity for the latter type of growth factor, and we purified a 70-kDa growth-potentiating factor (GPF) from the conditioned medium. Analyses of GPF and its cDNA revealed GPF to be a gamma-carboxyglutamic acid-containing protein encoded by a growth arrest-specific gene, gas6, which related to protein S. GPF specifically potentiated cell proliferation mediated by Ca(2+)-mobilizing receptors. The presence of a specific binding site suggests that the effect of GPF is mediated by a receptor. Thus, GPF may be a new type of extracellular factor regulating VSMC proliferation.

Amino Acid Sequence↗
PubMed1995

Characterization of hepatic allograft infiltrates in rats pretreated with donor-specific blood transfusion (DST).

A single intravenous injection of 1 ml freshly heparinized donor blood given 7 days prior to transplantation prolonged significantly the survival of subsequent hepatic allografts in fully allogeneic ACI(RT1a)-to-LEW(RT1(1)) rats. The cellular identity of allograft infiltrates was investigated at various times after transplantation using OX8 (CD8) and W3/25 (CD4) monoclonal antibodies. The number of CD8+ cells increased rapidly and reached a peak on Day 3 after transplantation of the untreated allografts. Similarly, the number of CD8+ cells in the allografts from DST-treated rats was maximum on Day 3 and decreased gradually thereafter. The maximum number of CD4+ cells was found on Day 3 in untreated allografts. In contrast, no significant infiltration of CD4+ cells occurred during the first 7 days after transplantation in DST-treated allografts. Thereafter, the number of CD4+ cells increased rapidly and reached a peak on Day 14. CD4+ cells remained persistently elevated in hepatic allografts of rats pretreated with DST, but did not become functionally competent or initiate rejection. These findings suggest that persistent infiltration by CD4+ cells is a characteristic feature of long-surviving hepatic allografts in rats pretreated with DST.

Animals↗
PubMed1995

Plasmid profiles of Klebsiella pneumoniae isolated from bovine mastitis.

Plasmids of Klebsiella pneumoniae strains isolated from mastitic milk of cows were detected, and the epidemiological significance of their profiles was investigated. Of 47 K. pneumoniae isolates, 41 (87.2%) possessed plasmid(s). Although the molecular size of the plasmids ranged from 1.9 to 140 megadaltons (Md), the 125 Md plasmid was predominant (31/41, 75.6%). There was a great diversity in the plasmid profiles, however, no correlation was found between the plasmid profiles and capsular types of Klebsiella or the source of strains (dairy farms), except for one farm. All isolates obtained from cows on that farm possessed the 125 Md plasmid and their capsular type was 9.

Animals↗
PubMed1995

Possible anti-tumour-promoting activity of components in Japanese soybean fermented food, Natto: effect on gap junctional intercellular communication.

In order to detect any protective agent against tumor formation, we examined the anti-tumor-promoting effect of a Japanese traditional soybean fermented food, Natto. Dye transfer was employed as an assay method. When fluorescent dye was microinjected into cultured BALB/3T3 cells, the dye was transformed into the neighboring cells through the gap junction. This dye transfer was blocked by the treatment with the tumor promoters 12-O-tetra-decanoylphorbol-13-acetate (TPA), a high concentration of NaCl and lithocholic acid (LCA). This reduction of the dye transfer by TPA treatment was not observed when the cells were pretreated with retinoic acid, an anti-tumor promoter. Thus, the recovery of the dye transfer in TPA-treated BALB/3T3 cells was proven to ge a good indicator for detecting some possible anti-tumor promoters. After extraction and fractionation of Natto, we obtained an active fraction (H1) which showed recovery of the dye transfer in TPA-treated cells. The fraction contained straight-chain saturated hydrocarbons. A comparison of the fraction and the authentic samples by GC analysis suggests that the H1 fraction contained straight-chain saturated hydrocarbons from around C30 to C32. Among these hydrocarbons, hentriacontane (C31) was found at the highest concentrations, and was shown to have the highest activity. Hentriacontane at a very low concentration of 0.65 ng/ml was shown to recover the dye transfer inhibited by the treatment with TPA as well as with NaCl and LCA.

3T3 Cells↗
PubMed1995

[A case of tuberculous meningitis followed by tuberculoma with pan-hypopituitarism].

We reported a case who suffered from tuberculous meningitis at 10 months of age, and progressed to basal tuberculoma despite intensive drug therapy with isoniazid, rifampin, and streptomycin. Pan-hypopituitaliam due to basal tuberculoma was effectively replaced by the administration of anti-diuretic hormone (DDAVP) and levothyroxine sodium. Basal tuberculoma was finally removed by surgical operation. Histopathological examination of the tuberculoma revealed Mycobacterium tuberculosis and Langhans giant cells. During the 6 years after the operation, her growth rate was found to be retarded, and the administration of human growth hormone was started. Remarkable catch-up growth was demonstrated. We like to emphasize that infantile tuberculosis, mostly a result of intafamilial transmission, may manifest meningitis in the early phase of the disease, and it sometimes progresses to basal tuberculoma unresponsive to anti-mycobacterial drug therapy.

Child↗
PubMed1995

Plasmid profiles of Klebsiella pneumoniae isolated from horses.

Plasmid profiles of Klebsiella pneumoniae isolated from horses were examined. Thirty-nine strains of K. pneumoniae capsular type 1 (K1) isolated from cervical swabs of mares suffering from metritis, and from semen of stallions showed similar plasmid profile patterns, and all strains possessed a 125 megadaltons (Md) plasmid. There was no difference in plasmid profiles between the heavily-encapsulated and the less heavily-encapsulated strains of K. pneumoniae K1. Non-capsulated variants derived from the strains of K1 showed the same plasmid profile pattern as the parent strains. Plasmid profiles of K. pneumoniae other than K1 were various, and none of these strains possessed the 125 Md plasmid.

Animals↗
PubMed1995

Assignment of the bacterial agent of urinary calculus in young rats by the comparative sequence analysis of the 16S rRNA genes of corynebacteria.

Comparative 16S rRNA gene sequencing was used to assign four isolates of spontaneous urinary calculus in young laboratory rats. The phylogenetic relationships among the rat isolates and selected species of corynebacteria were also inferred. Based on the homology and evolutionary distance analysis, the 16S rRNA genes of the rat isolates were almost identical with that of Corynebacterium renale ATCC 19412. Also the results of the phylogenetic analysis showed a close relationship among the isolates and C. renale, but they were clearly different from C. pilosum, C. cystitidis, C. kutscheri and Rhodococcus equi. The results of the present study and previously published biochemical data demonstrate that the organism involving urinary infections in young rats is identified to be C. renale.

Animals↗
PubMed1994

Molecular cloning of pancreatic group I phospholipase A2 receptor.

We have recently reported that mammalian pancreatic group I phospholipase A2 (PLA2-I) has its specific receptor (PLA2 receptor) on a variety of mammalian cells and that various biological responses are elicited by PLA2-I via this receptor. In this study, we cloned cDNAs encoding a protein corresponding to the bovine PLA2 receptor purified from the corpora lutea on the basis of its partial amino acid sequences. The identity of a protein encoded by the cloned cDNA with the bovine PLA2 receptor was verified by a transient expression experiment using COS-7 cells. Interestingly, the deduced primary structure of the PLA2 receptor (1,463 amino acid residues) exhibits a close relatedness throughout the molecule to that of the macrophage mannose receptor, a unique member of Ca(2+)-dependent (C-type) animal lectin family, in spite of their functional diversity. Based on this sequence similarity between these two receptors, the domain organization of the PLA2 receptor could be tentatively assigned as follows; 10 extracellular domains including 8 tandem repeats homologous to C-type carbohydrate-recognition domains (CRDs) and a single transmembrane region followed by a short cytoplasmic tail. The results of transient expression experiments for mutant PLA2 receptors supported this assignment and furthermore suggested the region responsible for PLA2-I binding corresponds to CRDs in the mannose receptor.

Amino Acid Sequence↗
PubMed1994

Plasmin converts pro-form of group I phospholipase A2 into receptor binding, active forms.

Treatment of zymogen of pancreatic-type group I phospholipase A2 (PLA2-I) by plasmin, a fibrinolytic enzyme, increases PLA2 activity as well as receptor binding activity in a dose- and time-dependent manner. Separation of plasmin-treated pro-PLA2-I by HPLC and amino acid sequence analysis of the products revealed that, in addition to an authentic mature PLA2-I produced by trypsin, plasmin produced active products which had been modified in the C-terminal region. Thus, PLA2-I may be involved in physiologic processes which accompany the formation of plasmin.

Amino Acid Sequence↗
PubMed1994

Isolation and partial characterization of crystal matrix protein as a potent inhibitor of calcium oxalate crystal aggregation: evidence of activation peptide of human prothrombin.

In order to clarify the characteristics of crystal matrix protein (CMP), which exhibits a remarkable affinity for calcium oxalate crystals and may be important in stone pathogenesis, we have isolated CMP from macromolecular matrix substances of newly-formed calcium oxalate crystals. Purification of CMP consisted of calcium oxalate crystal formation, dissolution of crystals, electrodialysis, anion exchange chromatography and high-performance liquid chromatography. CMP showed the protein band of 31 kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The N-terminal amino acid sequence of CMP was identical to that of human prothrombin. Both anti-CMP polyclonal antibody and anti-human prothrombin antibody cross-reacted well with human prothrombin and CMP in Western blotting. Its amino acid composition and its molecular weight of 31 kDa strongly suggest that CMP is the activation peptide of human prothrombin.

Adult↗
PubMed1994

A homogenization sampling procedure for calculating trabecular bone effective stiffness and tissue level stress.

A homogenization sampling procedure is introduced which allows computation of effective trabecular bone stiffness and individual trabecula level stress based on precise models of trabecular bone architecture. Three-dimensional digitized images of 53 trabecular bone specimens with a resolution of 50 microns per voxel were directly converted into three-dimensional finite element meshes by making each voxel an 8-node isoparametric brick element. Owing to the large mesh of 8000 elements, an element-by-element preconditioned conjugate gradient (EBEPCG) program was written to solve the local homogenization finite element equations. Predicted effective stiffness measures correlated well with experimental results (R2 > 0.73). The predicted effective stiffness tended to under estimate the experimental values. Average absolute errors in effective stiffness estimates ranged between 31 and 38% for the sampling procedure compared to a range 49-150% for a regression fit to volume fraction squared. Trabecula level stress ranged between -200 and +300 times that predicted by analyzing trabecular bone as a continuum. Both tensile and compressive tissue stresses were engendered by a continuum compressive stress. Trabecula level strain energy density (SED) ranged between 0 and 100 times the continuum SED value for two trabecular specimens. In conclusion, the homogenization sampling procedure consistently predicted the influence of trabecular bone architecture on effective stiffness. It can also provide trabecular tissue stress and strain estimates for arbitrary global loading of whole bones. Tissue stresses and strains showed large variations compared to corresponding continuum level quantities.

Bone and Bones↗
PubMed1994

Protection from caseous lymphadenitis in sheep by spraying iodine tincture on shearing wounds.

The effect of spraying shearing wounds with iodine tincture on Corynebacterium pseudotuberculosis infection in lambs was examined. The ELISA-negative lambs which had received some visible wounds during their first shearing were randomly divided into two groups: one was sprayed with iodine tincture on wounds after shearing, and the other was not. Anti-C. pseudotuberculosis toxin titers were measured by ELISA. The seroconversion ratio of the group with iodine tincture treatment 3 months after shearing was smaller than that of the untreated group (P < 0.05). These results suggest that treatment of shearing wounds with iodine tincture is effective in the protection of C. pseudotuberculosis infection in lambs.

Administration, Topical↗
PubMed1994

The use of fluorescent dextrans as a marker of sarcolemmal injury.

We investigated the use of intravenously injected fluorescent dextran molecules (FDx) as a histological marker of sarcolemmal injury. Using fluorescent microscopy, uptake of FDx (average MW 10 kD) was assessed in sections of quadriceps muscles from three models: 1) normal (C57BL/10SnJ) mice, 2) normal mice run downhill (0, 3, and 7 days post exercise), and 3) non-exercised mdx (dystrophin-deficient) mice. These were compared to serial sections stained with hematoxylin and eosin (H&E). In control muscles, strong fluorescence was seen between fibers (intercellular). Intracellular FDx was observed within cells of the quadriceps from normal mice run downhill at days 0 and 3 post exercise, but not at day 7. On H&E staining, muscle pathology was not observed until day 3, with regeneration by day 7. Intracellular FDx was also observed within mdx muscles, particularly in fibers that appeared pre-necrotic on H&E stained sections. FDx appears to be useful as a histological marker of changes in sarcolemmal integrity associated with muscle injury from eccentric exercise or muscle disease.

Animals↗
PubMed1994

[Effect of nicardipine cardioplegia on A-V conduction system in coronary bypass surgery].

The effect of diltiazem and nicardipine cardioplegia on A-V conduction system was analyzed in 75 patients undergoing coronary bypass operation. The dose of these drugs into the crystalloid cardioplegia was 10 micrograms/kg in nicardipine group (n = 29) and 100 micrograms/kg in diltiazem group (n = 46). Among these patients, there was no operative death and no patient required IABP after surgery and there was no difference on the post operative CK-MB level, on the cardiac index and on the pulmonary pressure between two groups. The number of patients who had complete A-V block after release of aortic cross clamping was significantly smaller in nicardipine group than in diltiazem group: 45.7% in diltiazem group vs. 6.9% in nicardipine group at 30 minutes and 21.7% vs. 6.9% at 60 minutes. We conclude that the suppressive effect on A-V conduction system was significantly lower in nicardipine cardioplegia than in diltiazem cardioplegia in the patients undergoing coronary bypass operation.

Angina Pectoris↗
PubMed1994

Liver regeneration after orthotopic reduced-size hepatic transplantation in the rat.

These experiments were undertaken to study the effects of cyclosporine on liver regeneration after an isogeneic orthotopic reduced-size hepatic transplantation in rats. The incorporation of bromodeoxyuridine into the DNA of the remnant hepatocytes was evaluated at various time points by immunohistochemical staining. Cyclosporine (10 mg/kg/day) significantly augmented BrdU incorporation into hepatocytes after hepatectomy. The maximum labeling index was observed at 24 hr after hepatectomy. In contrast, the maximum labeling index in the recipient rats not receiving cyclosporine was seen at 36 hr after reduced-size hepatic transplantation, and 10 mg/kg/day of cyclosporine decreased the labeling index at 36 hr after grafting. A lower dose of cyclosporine (3 mg/kg/day), however, significantly increased the labeling index in the recipient rats, which reached a peak at 24 hr after grafting as compared with the transplant recipients not receiving cyclosporine. This dosage shortened the time it took for the reduced-size hepatic transplant labeling index to peak. These findings suggest that after reduced-size hepatic transplantation, the liver graft is more sensitive to both hepatotrophic and hepatotoxic effects of cyclosporine.

Animals↗