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R Kido

Publications and source records attributed to R Kido.

At least 19 recordsLinked to original sources
PubMed2007

Regulation of calprotectin expression by interleukin-1alpha and transforming growth factor-beta in human gingival keratinocytes.

BACKGROUND AND OBJECTIVE: Calprotectin, a heterodimer of S100A8 and S100A9 with antimicrobial properties, is expressed in gingival keratinocytes and plays an important role in innate immunity. Because calprotectin expression is localized in the spinous cell layer of the gingival epithelium, we hypothesized that the expression of calprotectin in keratinocytes is related to the differentiation stage. The aim of the present study was to investigate the relationship between calprotectin expression and keratinocyte differentiation using some factors that regulated its differentiation. MATERIAL AND METHODS: Normal human gingival keratinocytes were isolated from gingival tissues obtained at the extraction of wisdom teeth, and were cultured in serum-free keratinocyte medium supplemented with interleukin-1alpha or calcium, which promote keratinocyte differentiation, and transforming frowth factor-beta (TGF-beta) or retinoic acid, which suppress its differentiation. The expression of S100A8/A9 mRNA and the production of calprotectin in normal human gingival keratinocytes were examined by northern blotting and enzyme-linked immunosorbent assay, respectively. The expression of cytokeratin 14, involucrin and filaggrin (marker proteins of keratinocyte differentiation) was investigated by immunohistochemical staining, and the DNA-binding activity of CCAAT/enhancer binding protein alpha (C/EBPalpha), a transcription factor, was examined by electrophoretic mobility shift assay. RESULTS: The expression of S100A8/A9 mRNA and the production of calprotectin were increased by interleukin-1alpha and calcium, but decreased by TGF-beta. RA inhibited the expression of S100A8/A9 and keratinocyte differentiation, which were induced by interleukin-1alpha. C/EBPalpha DNA-binding activity in normal human gingival keratinocytes was enhanced by interleukin-1alpha and calcium, but suppressed by TGF-beta. CONCLUSION: The present study suggests that calprotectin expression is related to keratinocyte differentiation and that C/EBPalpha is a regulator of calprotectin expression in keratinocytes.

CCAAT-Enhancer-Binding Protein-alpha↗
PubMed2004

Induction of calprotectin release by Porphyromonas gingivalis lipopolysaccharide in human neutrophils.

Calprotectin, a major cytosolic protein of leukocytes, is detected in neutrophils, monocytes/macrophages, and epithelial cells. This protein is known to be a marker for several inflammatory diseases and is detected in inflammatory gingival tissue with periodontal disease. Recently, we found that the calprotectin level in gingival crevicular fluid from periodontitis patients was significantly higher than that of healthy subjects. However, the regulation of calprotectin in periodontal disease is unclear. In the present study, we investigated the effect of lipopolysaccharides of periodontopathic bacteria on calprotectin release from human neutrophils. Neutrophils from healthy donors were treated with lipopolysaccharides from Porphyromonas gingivalis (P-LPS), Actinobacillus actinomycetemcomitans, Prevotella intermedia, Fusobacterium nucleatum, and Escherichia coli. Calprotectin of neutrophil was identified by immunoblotting and calprotectin amount was determined by ELISA. Two subunits (10 and 14 kDa) of calprotectin were observed in the cell and medium fractions from neutrophils. P-LPS increased calprotectin release from seven to 16 times the control level after 30 min and its effect appeared in a dose-dependent manner (10-1000 ng/ml). Lipopolysaccharides from A. actinomycetemcomitans, P. intermedia, F. nucleatum, and E. coli also induced calprotectin release from neutrophils. These results suggest that lipopolysaccharides from periodontopathic bacteria induce calprotectin release from human neutrophils.

Adult↗
PubMed2001

Life style and urinary 8-hydroxydeoxyguanosine, a marker of oxidative dna damage: effects of exercise, working conditions, meat intake, body mass index, and smoking.

The urinary levels of 8-hydroxydeoxyguanosine (8-OH-dG), a marker of oxidative DNA damage, of 318 healthy men aged 18 - 58 were measured with high resolution by a newly developed automated high-pressure liquid chromatography (HPLC) system coupled to an electrochemical detector (ECD). The mean 8-OH-dG level (mg / g creatinine) was 4.12 +/- 1.73 (SD). An eleven-fold inter-individual variation was observed. The accuracy of the measurement estimated from the recovery of an added 8-OH-dG standard was 90 - 98%. By univariate analysis, it was found that moderate physical exercise (P = 0.0023) and high body mass index (BMI) (P = 0.0032) reduced the 8-OH-dG level, while physical labor (P = 0.0097), smoking (P = 0.032), and low meat intake (less than once / week) (P = 0.041) increased its level. Based on a multi-regression analysis of the log-transformed values, moderate physical exercise (P = 0.0039), high BMI (P = 0.0099), and age (P = 0.021) showed significant reducing effects on the 8-OH-dG level, while low meat intake (P = 0.010), smoking (P = 0.013), and day-night shift work (P = 0.044) increased its level. These results suggest that many types of life-style factors that either generate or scavenge oxygen radicals may affect the level of oxidative DNA damage of each individual.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2000

Analyses of oxidative DNA damage and its repair activity in the livers of 3'-methyl-4-dimethylaminoazobenzene-treated rodents.

We measured the levels of 8-hydroxyguanine (8-OH-Gua) and its repair activity in the livers of the Donryu rat, the carcinogen-resistant DRH rat, and the ddy mouse, which were fed a 0.06% 3'-methyl-4-dimethylaminoazobenzene (3'-MeDAB)-containing diet. In a short-term rat experiment (maximum 2 months), 3'-MeDAB did not increase the 8-OH-Gua levels in the livers of the two rat strains, although it significantly increased the repair activity in only the Donryu rat liver at 1 and 2 months. After long-term 3'-MeDAB administration to the ddy mouse (8 months), the levels of 8-OH-Gua and its repair activity were increased in the liver by 3.6-fold and 1.6-fold, respectively. These experiments suggest that 3'-MeDAB increases 8-OH-Gua generation in rodent liver DNA and the 8-OH-Gua repair assay is a reliable marker of cellular oxidative stress induced by carcinogens.

Animals↗
PubMed2000

The association of calprotectin level in gingival crevicular fluid with gingival index and the activities of collagenase and aspartate aminotransferase in adult periodontitis patients.

BACKGROUND: Calprotectin, a major cytosol protein of leukocytes, exists in plasma and other body fluids of healthy human subjects. Since the calprotectin concentration rises markedly in some inflammatory diseases including rheumatoid arthritis, this protein has been thought to be a marker of inflammatory disease. Recently, we identified calprotectin in human dental calculus and gingival crevicular fluid (GCF), and found that the calprotectin concentration in GCF from patients with periodontitis was significantly higher than that in GCF from healthy subjects. In the present study, the association of GCF calprotectin level with GCF volume, gingival index (GI), and levels of biochemical markers including collagenase and aspartate aminotransferase (AST) in GCF was investigated to clarify the relationship between GCF calprotectin level and periodontal inflammation. METHODS: Ninety GCF samples collected from periodontal pockets with a probing depth of more than 4 mm in 54 patients with adult periodontitis were used for these assays. The GCF volume was measured, and GI in each site was recorded. The calprotectin content in GCF samples was determined by ELISA using a specific antibody. The activity of collagenase or AST was measured by a respective assay kit. RESULTS: The total amount of calprotectin and GCF volume showed a highly significant correlation (r = 0.64, P <0.0001), whereas the calprotectin concentration had no correlation with the GCF volume (r = 0.01, P= 0.924). The mean calprotectin concentration in GCF increased with the degree of GI, and the concentration in individual samples was significantly correlated with the GI score (r = 0.56, P<0.0001). Significant positive correlations were observed in GCF calprotectin versus collagenase (r = 0.57, P <0.0001) and GCF calprotectin versus AST levels (r = 0.40, P <0.005). CONCLUSIONS: From the present results and our previous findings, it is shown that the GCF calprotectin level significantly correlates not only with clinical indicators but also with current biochemical marker levels and that calprotectin may be a useful marker for periodontal inflammation.

Adult↗
PubMed1999

Calprotectin in gingival crevicular fluid correlates with clinical and biochemical markers of periodontal disease.

Clinical and biochemical markers of periodontal disease have been used for precise objective diagnosis of periodontal inflammation. Interleukin 1beta (IL-1beta) and prostaglandin E2 (PGE2), inflammatory factors, levels in gingival crevicular fluid (GCF) of patients with periodontal disease are elevated and have been studied as biochemical markers. The levels of calprotectin, a leukocyte protein, in body fluids of patients with some inflammatory diseases are raised. Recently, we detected calprotectin in GCF and its concentrations in periodontal pockets were higher than those in healthy gingival crevices. In this study, we investigated the correlations between GCF calprotectin levels and clinical indicators (probing depth and bleeding on probing, BOP), and the IL-1beta or PGE2 levels in GCE Probing depth and BOP at 130 sites of 110 subjects with periodontal or other oral diseases were examined, then GCF samples were collected and their calprotectin, IL-1beta and PGE2 were determined by ELISA. The calprotectin level correlated positively with the probing depth and was significantly higher at BOP-positive than BOP-negative sites. There were significant, positive correlations between the calprotectin and IL-1beta or PGE2 concentrations. These results indicate that the calprotectin level in GCF correlates well with clinical and biochemical markers of periodontal disease and suggest that calprotectin may be useful for evaluating the extent of periodontal inflammation.

Adult↗
PubMed1998

Inhibition in vitro linoleic acid peroxidation and haemolysis by caffeoyltryptophan.

Antioxidant activities of caffeoyltryptophan were investigated by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging system, the superoxide anion generation system and the superoxide anion-mediated linoleic acid peroxidation system. At 10 microM, caffeoyltryptophan showed greater scavenging activity on DPPH than dl-alpha-tocopherol or ascorbic acid. DPPH radical scavenging activity of caffeoyltryptophan increased dose-dependently at concentrations ranging from 1 to 50 microM; 1 mol of caffeoyltryptophan reacted with ca 4 mol of radical. Caffeoyltryptophan caused 80% inhibition of superoxide anion generation at 50 microM. The inhibitory activity of caffeoyltryptophan was as strong as that of 5-caffeoylquinic acid. Caffeoyltryptophan inhibited the formation of conjugated diene from linoleic acid. The inhibitory activity increased in the order caffeic acid < 5-caffeoylquinic acid < caffeoyltryptophan < dl-alpha-tocopherol. Effects on the in vitro haemolysis and peroxidation of mouse erythrocytes induced by H2O2 were also examined. Caffeoyltryptophan exhibited strong inhibitory activities; Tryptophan was ineffective in these systems. These data suggest that caffeoyltryptophan may be a natural antioxidant in the human diet and, as such, may intervene in toxicological processes that are mediated by radical mechanisms.

Animals↗
PubMed1997

Immuno-localization of kynurenine aminotransferase (KAT) in the rat medulla and spinal cord.

In the mammalian brain, kynurenine aminotransferase (KAT) is pivotal to the synthesis of kynurenic acid, a preferential antagonist at the strychnine-insensitive NMDA-glycine site. As NMDA receptors are involved in autonomic function, we have examined the immunohistochemical localization of KAT in the medulla and spinal cord of the rat. KAT immunoreactivity (KAT-li) was found throughout these areas, in both glia and neurons. Unlike the mainly astrocytic localization in forebrain structures, KAT-li was predominantly neuronal, notably in areas important for blood pressure and heart rate regulation: ventral medulla, nucleus ambiguus, nucleus of the solitary tract and intramediolateral cell column of the spinal cord. The presence of KAT in these nuclei supports a neuromodulatory role for kynurenic acid in NMDA-mediated autonomic function.

Animals↗
PubMed1997

Cloning and recombinant expression of rat and human kynureninase.

Kynureninase [E.C.3.7.1.3.] is one of the enzymes involved in the biosynthesis of NAD cofactors from tryptophan through the kynurenine pathway. By tryptic and CNBr digestion of purified rat liver kynureninase, we obtained about 28% of the amino acid sequence of the enzyme. The rat kynureninase cDNA, isolated by means of reverse-transcribed polymerase chain reaction and hybridization screening, codes for a polypeptide of 464 amino acids. Northern blot analysis revealed the synthesis of a 2.0 kb rat kynureninase mRNA. A cDNA encoding human liver kynureninase was also isolated. The deduced amino acid sequence is 85% identical to that of the rat protein. COS-1 cells were transfected with both cDNAs. The Km values of the rat enzyme, for L-kynurenine and DL-3-hydroxykynurenine, were 440 +/- 20 microM and 32 +/- 5 microM and of the human enzyme 440 /- 20 microM and 49 +/- 6 microM, respectively. Interestingly, COS-1 cells transfected with the cDNA coding for rat kynureninase also display cysteine-conjugate beta-lyase activity.

Amino Acid Sequence↗
PubMed1995

Metabolic inter-organ relations by exercise of fed rat: carbohydrates, ketone body, and nitrogen compounds in splanchnic vessels.

Fed rats were exercised until exhaustion by almost 65% VO2max on a treadmill. In 2.5 min after the exercise, blood was collected from various vessels of the splanchnic bed. Metabolites, glucose, lactate, ketone body, and nitrogencompounds in the plasma, were measured. Glucose excretion from the liver was increased by exercise, but was not significant. The absorption by the kidney decreased to 30% by exercise. Lactate was highly absorbed by the kidney, lower limbs, and digestive tract by exercise. Exercise caused a 200-300% increase of the plasma beta-hydroxybutyrate, but the absorption by the kidney and the lower limbs was decreased. These data suggest that glucose is a good carbon source for the recovery, and that lactate is more useful than glucose, but ketone body is less effective at a very early recovery phase under fed condition. Amino acid balances in each organ except digestive tract were positive showing anabolic conditions of these organs even after exhaustive exercise at fed condition. Most amino acid concentrations in the plasma tended to decrease to 60-90% by exercise. Amino acids were excreted from the digestive tract, and were eventually absorbed by the liver in both rested and exercised rat. The digestive tract, therefore, seems to be a primary amino acids pool to supply them to the liver during the inter meal. Urea excretion from the liver was more than the absorbed ammonia showing that active deamination from amino acids was carrying on. The resulted carbon skeletons of the amino acids might be used for the gluconeogenesis in the liver.

Amino Acids↗
PubMed1995

Molecular cloning and sequencing of a cDNA encoding alanine-glyoxylate aminotransferase 2 from rat kidney.

Alanine-glyoxylate aminotransferase (AGT) 2 is a pyridoxal 5'-phosphate dependent, mitochondrial enzyme which, in the rat, is expressed at a high level in the kidney. The amino acid sequences of nine tryptic and seven CNBr peptides of the rat kidney AGT2 were determined. Three overlapping cDNAs encoding the AGT2 were cloned on the basis of its partial amino acid sequences by means of a polymerase chain reaction-based approach involving rat kidney poly(A)+ RNA. The complete cDNA sequence comprised 1,919 bases, and contained a 1,536-base open reading frame which encodes a polypeptide of 512 amino acid residues with a putative presequence consisting of 39 amino acid residues at the amino terminus, giving a precursor protein with a molecular mass of 57,150 Da. The sequence of AGT2 exhibits significant homology with neither peroxisomal AGT1 from human liver nor mitochondrial AGT1 from rat liver. However, the sequence of AGT2 exhibited 30.8, 29.2, and 27.1% identity with those of Escherichia coli 4-aminobutyrate aminotransferase, rat ornithine aminotransferase, and Pseudomonas cepacia 2,2-dialkylglycine decarboxylase, respectively. The active site sequences were also well conserved among these aminotransferases. AGT2, thus, is more similar to the other aminotransferases than to AGT1. The results suggest that the rat kidney AGT2 may play a biological role in amino acid metabolism distinct from that of AGT1.

Alanine Transaminase↗
PubMed1995

Spin-labelling study of biomembranes in spontaneously hypertensive rats: calcium- and calmodulin-dependent regulation.

1. The present study was performed to investigate alterations in membrane characteristics of spontaneously hypertensive rats (SHR) by using an electron paramagnetic resonance (EPR) and spin-labelling methods. 2. Washed erythrocytes from SHR were examined and compared with erythrocytes from age-matched normotensive Wistar-Kyoto (WKY) rats. 3. The values of outer hyperfine splitting (2T' 11) and that of the order parameter (S) obtained from EPR spectra for a spin label agent (5-nitroxide stearate) were significantly higher in the erythrocytes of SHR than in those of WKY rats. 4. When calcium (Ca2+) was loaded to erythrocytes with a Ca2+ ionophore (A 23187), the order parameter (S) of the EPR spectra showed a greater increase in SHR than in WKY rats. Furthermore, the Ca2+ -induced change in the order parameter (S) of SHR was significantly antagonized by pretreatment of the Ca2+ antagonists (verapamil, diltiazem) and a calmodulin antagonist (W-7). 5. The results show that the erythrocyte membranes of SHR tolerated different spin motions from those of normotensive WKY rats in the EPR study, which might be associated with the idea that the membrane fluidity might be lower in SHR. Furthermore, the data suggest that Ca2+ -calmodulin antagonists may ameliorate the Ca2+ -induced changes in membrane functions in hypertension.

Animals↗
PubMed1995

Tryptophan 2,3-dioxygenase in Saccharomyces cerevisiae.

The tryptophan pyrrole-ring cleavage enzyme (TPCE) was detected in the yeast Saccharomyces cerevisiae. TPCE activity existed constitutively and was markedly induced by culturing the cells in a medium containing 0.1% (w/v) L-tryptophan. We purified partially the enzyme from the L-tryptophan-induced cells by phospho-cellulose column chromatography. The partially purified enzyme was stimulated solely by L-ascorbic acid, a nonspecific reductant, suggesting that the yeast TPCE is not indoleamine 2,3-dioxygenase, but rather tryptophan 2,3-dioxygenase. The enzyme metabolized L-tryptophan preferentially, and D-tryptophan slightly. KCN and NaN3, exogenous ligands of heme, inhibited the enzyme activity drastically, indicating that yeast tryptophan 2,3-dioxygenase contains heme(s) in its active site. The optimal pH of the enzyme was 6.5. Upon two-dimensional polyacrylamide gel electrophoresis, a protein staining spot was identified that was induced by L-tryptophan and whose intensity changed in correlation with the tryptophan 2,3-dioxygenase activity after phospho-cellulose column chromatography. This protein, exhibiting a molecular weight of approximately 38,000 and an isoelectric point of approximately pH 8.0, may be identified as a subunit of yeast tryptophan 2,3-dioxygenase.

Azides↗
PubMed1995

Changes in serum lipid profile and esterases of rats after sublethal daily doses of dimethoate.

Male Wistar rats were injected by dimethoate (10 mg/0.5 ml) daily for 8 successive days. Controls received the same amount of saline., A group of 5 rats were anesthetized at 0, 2, 4, 6 and 8 days of injection. Blood was withdrawn from heart. serum lipid components and 4 species of serum esterases were assayed for each group. A general decrease in the activities of serum esterases was observed. A marked decrease also was observed in lipids profile during the 8 days course of experiment.

Acetylcholinesterase↗
PubMed1994

DNA fragmentation during the programmed cell death in the chick limb buds.

Programmed cell death plays a crucial role in limb morphogenesis of amniote. So far, there has been no biochemical evidence found to support the fact that embryonic cell death is apoptosis. In this report, we show the oligo-nucleosomal ladder pattern of DNA obtained from interdigital tissues of chick leg buds, indicating that programmed cell death has some features that are common to those involved in apoptosis. Furthermore, cells exhibiting DNA fragmentation were detected by using a method of in situ end labeling of DNA breaks. The distribution pattern of those cells corresponded well to those of programmed-dead cells situated within the interdigital mesenchyme of the leg bud.

Animals↗