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K Okano

Publications and source records attributed to K Okano.

At least 91 records · Page 5Linked to original sources
PubMed1998

Hepatocyte nitric oxide production is induced by Kupffer cells.

To investigate the cellular communication in the liver, nitric oxide (NO) production by sinusoidal cells and hepatocytes by stimulation with cytokines and Kupffer cell-conditioned medium was quantitatively analyzed. NO production by the cells was measured by the Griess reaction, and nitric oxide synthase (iNOS) transcription level by a competitive RT-PCR assay using mutant iNOS mRNA as a standard. NO production and iNOS mRNA transcriptional levels in Kupffer cells were markedly increased by stimulation with lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma), and moderately by interleukin-1beta (IL-1beta). NO production by hepatocytes was not significantly enhanced by LPS, but was markedly enhanced by IL-1beta or the combination of tumor-necrosis factor-alpha (TNF-alpha) and IFN-gamma. Hepatocyte NO production and iNOS mRNA levels were markedly enhanced by the LPS-activated Kupffer cell conditioned medium, but these effects were reduced by heat treatment or anti-TNF antibody. Although NG-monomethyl-L-arginine acetate and dexamethasone reduced NO production by the cells, the iNOS mRNA level was reduced by dexamethasone only. Gel-shift assay showed NF-kappaB activation in hepatocytes during this activation. These data reinforce the importance of cellular communication between sinusoidal cells and hepatocytes.

Animals↗
PubMed1998

Involvement of spinal substance P and excitatory amino acids in inflammatory hyperalgesia in rats.

To reveal possible involvement of NK-1 substance P receptors and N-methyl-D-aspartate (NMDA) and non-NMDA glutamate receptors in the production of inflammatory hyperalgesia, we examined the effects of intrathecal injections of antagonists at those receptors on the nociceptive threshold of inflammatory hyperalgesic rats in the paw-pressure test. Intrathecal injections of the NK-1 antagonist CP-96,345 (0.3-3 nmol/rat), the NMDA antagonist D-2-amino-5-phosphonovaleric acid (D-APV, 1-10 nmol/rat), and the non-NMDA antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX, 1-10 nmol/rat) dose-dependently suppressed adjuvant- and carrageenin-induced hyperalgesia, without effect on the nociceptive threshold of non-inflamed paws. Furthermore, to estimate whether inflammatory hyperalgesia is accompanied with an alteration of the responsiveness to substance P and excitatory amino acids, we examined the effects of injections of complete Freund's adjuvant (intradermal) and carrageenin (subcutaneous) on the aversive responses to intrathecal substance P and excitatory amino acid agonists. Both injections significantly potentiated the aversive behaviors elicited by intrathecal injections of excitatory amino acid agonists, NMDA (1 nmol/rat), a-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA, 1 nmol/rat) and kainate (1 nmol/rat), but not those by substance P. The present results suggest that the enhancement of synaptic transmission mediated by substance P and excitatory amino acids in the spinal dorsal horn is at least partly involved in the production of inflammatory hyperalgesia, and that such a hyperalgesia is accompanied with the enhanced responsiveness to excitatory amino acids through NMDA and non-NMDA receptors, but not with changes in responsiveness to substance P.

2-Amino-5-phosphonovalerate↗
PubMed1997

Genomic organization and functional analysis of the murine protein phosphatase 1c gamma (Ppp1cc) gene.

Protein phosphatase 1 holoenzymes are composed of catalytic subunits in combination with various regulatory subunits. In rodents, four different catalytic isoforms are known, PP1c alpha, -delta, -gamma 1, and -gamma 2. Here we describe the genomic organization of the murine Ppp1cc gene that encodes the PP1c gamma 1 and PP1c gamma 2 isoforms. We determined that Ppp1cc maps to F1.2-G1.2 on chromosome 5 by FISH mapping. Southern hybridization and analysis of cross-hybridizing genomic clones revealed four Ppp1cc-related pseudogenes in the mouse genome. The authentic Ppp1cc gene encodes two isoforms, PP1c gamma 1 and PP1c gamma 2, that arise from alternative splicing and differ by retention of the last intron. The introns of Ppp1cc are flanked by short direct repeats, the significance of which is not clear. Both isoforms retain phosphatase function since they are able to complement the cold-sensitive PP1 defect caused by the dis2-11 mutation in the fission yeast Schizosaccharomyces pombe.

Amino Acid Sequence↗
PubMed1997

Paternal transmission of the mouse Thp mutation is lethal in some genetic backgrounds.

Thp is a large deletion on chromosome 17 which includes the maternal lethal gene Tme. Documentation of inheritance patterns suggests that Tme is an imprinted gene which is required for viability; maternal deletion is lethal while paternal deletion is viable. However, paternal transmission of Thp is rarely the expected 50%. We show here that paternally inherited Thp is lethal in some strains, providing evidence of an incompletely penetrant, dosage sensitive lethal allele of a locus that probably maps to the hairpin tail region of chr. 17. Interpretation of the various phenotypes associated with loss of the putative Tme gene, Igf2r, may need to be revised in view of these observations.

Abnormalities, Multiple↗
PubMed1997

Expression of parathyroid hormone-related peptide in human osteoarthritis.

To evaluate the involvement of the expression of parathyroid hormone-related peptide gene in human articular cartilage pathology, we performed immunohistochemical staining and in situ hybridization on specimens of femoral head cartilage obtained from 15 patients with osteoarthritis, 11 with rheumatoid arthritis, and 12 control subjects. Parathyroid hormone-related peptide-positive chondrocytes were observed predominantly in degenerated lesions of osteoarthritic tissue and were less evident in rheumatoid arthritic samples, while the normal cartilage expressed little parathyroid hormone-related peptide. In addition, the level of parathyroid hormone-related peptide expression was clearly dependent on the degree of cartilage degeneration; cartilage tissues with moderate degenerative changes contained more positive chondrocytes compared with mildly or severely degenerated cartilage. In situ hybridization confirmed the localization of parathyroid hormone-related peptide protein and demonstrated intense expression of mRNA of the peptide in osteoarthritic samples. This is the first demonstration of parathyroid hormone-related peptide expression in chondrocytes from pathologic articular cartilage of humans. Our results suggest that parathyroid hormone-related peptide may be involved in the pathophysiology of osteoarthritis.

Aged↗
PubMed1997

Hepatic protein synthesis in the regenerating rat liver after hepatopancreatectomy.

To evaluate the effects of hepatopancreatectomy on the regenerative process of the liver, the serum protein changes, hepatic protein synthesis (HPS), and bromodeoxyuridine (BrdU) labeling index were measured in rats. Sprague-Dawley rats were divided into four groups according to the type of resection: A simple laparotomy was performed in the sham group; 68% of the liver was excised in the Hx group; 45% of the pancreas was excised in the Px group; and 45% of the pancreas and 68% of the liver were excised simultaneously in the HPx group. Serum total protein and albumin levels were significantly lower in the HPx group compared to the other three groups on postoperative day (POD) 3 (P < 0.05). HPS was markedly increased in the Hx and HPx groups. In the Hx group, it was significantly higher, peaking on POD 2, compared to the HPx group (P < 0.05), while in the HPx group, it was significantly higher compared to the Hx group (P < 0.05), peaking on POD 3. The BrdU labeling index, as a marker of DNA synthesis, was significantly suppressed in the HPx group on POD 1 compared to the Hx group (P < 0.05). Thus, compared to hepatectomy alone, hepatopancreatectomy suppresses DNA synthesis, causing a delay in the increase of protein synthesis in the regenerating liver, resulting in a more marked decrease in the serum protein level.

Alanine Transaminase↗
PubMed1997

Effect of repeated cold stress on capsaicin-evoked release of glutamate from rat spinal dorsal horn slices.

We investigated the effect of repeated cold stress (RCS) on the capsaicin-evoked release of glutamate from the primary afferent fibers of the rat, and compared this with the effect of inoculation of complete Freund's adjuvant (adjuvant inoculation). The release of glutamate was measured using a fluorometric on-line continuous monitoring system in which the immobilized glutamate dehydrogenase column was connected to an in vitro superfusion system. In the presence of 0.3 microM tetrodotoxin, the application of 1 microM capsaicin to spinal dorsal horn slices evoked glutamate release (18.6 +/- 1.2 pmol mg(-1) protein, n = 11). In rats subjected to RCS (RCS rats), the release of glutamate evoked by 1 microM capsaicin was markedly increased to 272% (n = 6, P < 0.05) of the value for the control group, although the basal release was not significantly altered (n = 6, P > 0.05). Adjuvant inoculation produced a significant increase in the basal and capsaicin (1 microM) evoked release of glutamate to 141 and 344% (n = 6, P < 0.05) of the value for the control group, respectively. The present results suggest that the facilitated release of glutamate from capsaicin-sensitive primary afferent terminals in the spinal dorsal horn is, at least in part, involved in the hyperalgesia of RCS rats as well as the complete Freund's adjuvant-induced hyperalgesia.

Animals↗
PubMed1997

[Clinical efficacy in pediatrics sinusitis infections of cefditoren pivoxil granule therapy and its in vitro antibacterial activity against clinically isolated strains].

We investigated the clinical efficacy in pediatrics sinusitis infections of cefditoren pivoxil granule therapy and its in vitro antibacterial activity against clinically isolated strains. The results are summarized as follows. The specimens from 343 patients were cultured and 595 strains of bacteria were isolated and identified. Oral doses of 3 and 5 mg/kg of CDTR-PI were clinically effective at high percentages, 85.1% and 89.5%, respectively, of treated patients. CDTR-PI at 3 mg/kg orally was clinically effective in 80.8% of patients with PCG intermediate S. pneumoniae (PISP) infections, 80.0% of those with PCG susceptible S. pneumoniae (PSSP) infections, 81.8% of those with H. influenzae infections and 78.3% of those with M. (B.) catarrhalis infections among the infections by major causative agents. The frequent isolates included S. pneumoniae accounting for 33.1%, H. influenzae accounting for 32.1%, M. (B.) catarrhalis accounting for 17.6% and S. pyogenes accounting 3.7% of all the isolates. PISP accounted for 16.1% of all the isolates and for 49.8% of the isolates of S. pneumoniae, and were isolated from 28.6% of the 343 patients. The isolation of PISP was frequent from children of 4 and under especially, and especially frequent from those below age 2. Of the isolates of S. pneumoniae, the biotype frequencies among PSSP were in the order of type I > type II > type III, while those among PISP were in the order of type I < type II with none of type III. Bacteriologically, an eradication rate of 89.4% was achieved with 3 mg/kg and 93.5% with 5 mg/kg of CDTR-PI.

Administration, Oral↗
PubMed1997

Synthesis of guanosine 5'-triphosphate analogues and their effect on microtubule assembly.

More than 20 base-modified analogues of guanosine 5'-triphosphate including 2'-deoxyguanosine derivatives were synthesized and examined their effect on tubulin polymerization into microtubules (Mts). Among those, 2,6-diamino-8-oxopurineriboside 5'-triphosphate (1d), 2,6-diamino-2'-deoxypurineriboside 5'-tri phosphate (1b) and 8-bromoguanosine 5'-tri phosphate (1g) were shown to have remarkable effect to promote microtubule assembly.

Guanosine Triphosphate↗
PubMed1996

Paternity testing by the detection of D1S80 VNTR using fluorescence image analyzer (Dualcolour system).

An improved method for DNA polymorphism typing of D1S80 VNTR locus and its application to paternity testing are described. For accurate estimation of the length of polymorphic DNA fragments, the size marker was labeled with fluorescence different from that of PCR primers, and co-electrophoresed as an internal standard. The dualcolour system of fluorescence image analyzer was used to detect the fragments and determine their size. This internal marker method could successfully overcome the problems of band pattern distortion and tailing, besides it allows easy and accurate interpretation of the DNA types. Our results indicate that the internal marker method is much more accurate than the method of using size marker in gel, even with the presence of distortion or tailing of the band patterns. Family studies applying this method showed complete agreement between the observed and predicted types.

Electrophoresis, Polyacrylamide Gel↗
PubMed1996

Fragment walking for long DNA sequencing by using a library as small as 16 primers.

A DNA sequence can be rapidly and efficiently determined by digesting it into segments small enough to be sequenced at one time, then assembling them into contigs by searching for overlaps. Fragment walking achieves this without subcloning or preparing many kinds of primers; fragments obtained by digesting a template DNA are sequenced in parallel directly from the fragment mixture by using a set of 16 primers. Since the sequence adjacent to each cutting site is determined together with the fragment sequence, the contiguous fragment can be easily determined. The complete template DNA sequence can thus efficiently determined. The sequencing of pUC19 (2.7 kb) from both sides was done in one step by using only 15 fragments. The redundancy was only about 1.3, greatly reducing base-reading redundancy. Automating this strategy would increase the speed and efficiency of large-scale DNA sequencing.

Base Sequence↗
PubMed1996

Selecting and amplifying one fragment from a DNA fragment mixture by polymerase chain reaction with a pair of selective primers.

A new method for selecting and amplifying a single DNA fragment from a mixture is proposed. This method is applicable for the rapid classification of DNA fragments from a mixture and for preparation of sequencing templates. DNAs of several to tens of kilobases (kb) are digested with a four-base recognition restriction enzyme to produce smaller fragments. The complementary strand extension reactions are then carried out to produce fluorophore-labeled DNA fragments from the digestion products. These fragments can be rapidly classified according to their terminal-base sequences and their sizes are analyzed by capillary-array gel electrophoresis (CAGE). Electropherograms are used to characterize the fragments and to select polymerase chain reaction (PCR) primers. Any fragment in a digestion mixture can be amplified by PCR with a pair of primers selected from a primer pool by referring to the electropherograms of the fragments. This method was successfully used to compare the electropherograms of two different DNA strands and to sequence a several-kb DNA fragment without subcloning. Combined with CAGE, this method could be used to dramatically simplify DNA fragment analysis.

DNA↗
PubMed1996

Increase in portal blood interleukin-6 soon after the commencement of digestive surgery.

To determine whether cytokines produced in the operative field during digestive surgery selectively spill over into the portal blood, the changes in interleukin-6 (IL-6) levels in portal and peripheral venous blood were assayed at several points in time from the commencement of surgery until 14 days later, in 11 patients. Similar changes in the IL-6 levels were observed in the portal and peripheral blood samples; however, the IL-6 levels in the portal blood reached a maximum 6-12h after the commencement of surgery, being earlier than in the peripheral venous blood. In fact, between 3 and 12h after the commencement of surgery, the IL-6 levels were higher in the portal blood by 33-81 pg/ml. By 24h or more after the commencement of surgery, the IL-6 levels did not differ significantly in the two types of blood samples. Moreover, the C-reactive protein levels 2 days after surgery were even more closely correlated to the maximum IL-6 levels in the portal blood than to those in the peripheral venous blood. These results suggest that IL-6 produced during intra-abdominal digestive surgery initially enters the portal blood, being trapped by IL-6 receptors in the liver, where it may regulate the synthesis of acute-phase proteins as a hepatocyte-stimulating factor.

Adult↗
PubMed1996

Comparison of University of Wisconsin and University of Pittsburgh solutions for heart transplantation.

The effectiveness of University of Wisconsin (UW) and University of Pittsburgh (UP) solutions for the preservation of rat hearts was compared. Lewis rat hearts were preserved with UW (group A, n = 45) or UP (group B, n = 45) solution for 0 or 24 h and then transplanted heterotopically into the recipients' abdomen. Ten recipients in each group were observed to obtain 1-week graft survival rates. Tissue water content and tissue content of adenine nucleotides were measured 2 h after transplantation in six grafts from each group. Six hearts preserved for 0 h and seven hearts preserved for 24 h were taken from each group 24 h after grafting for histopathology. The 1-week graft survival rates of groups A24 and B24 were 60% and 10%, respectively. In the 24-h preserved grafts, adenosine triphosphate (ATP) and energy charge [(ATP + adenosine diphosphate/2)/(ATP + adenosine diphosphate + adenosine monophosphate)] of groups A and B were 0.972 +/- 0.165 and 0.200 +/- 0.123 mg/g wet tissue (P < 0.05) and 74.4% and 61.1% (P < 0.05), respectively. The tissue water content of group A24 was 71.7%, whereas that of group B24 was 74.1% (P < 0.05). Histopathology revealed more severe muscle edema and necrosis and infiltration of polymorphonuclear cells in group B24 than in group A24. We conclude that UW solution is more appropriate for rat heart preservation than UP solution.

Abdomen↗
PubMed1996

Role of platelet-activating factor in pathogenesis of galactosamine-lipopolysaccharide-induced liver injury.

In an attempt to clarify the role of platelet-activating factor (PAF) in the pathogenesis of hepatic injury induced by galactosamine (GalN) plus lipopolysaccharide (LPS), effects of WEB 2086 (PAF receptor antagonist) on hepatic injury in vivo as well as on neutrophil adherence to hepatic endothelial cells in vitro have been investigated, as we have recently clarified the role of neutrophils in this experimental model of hepatic injury. Although an enhanced serum TNF-alpha level after GalN-LPS administration was not reduced by WEB 2086, hepatic injury and hepatic neutrophil accumulation in the liver after GalN-LPS administration were attenuated by WEB 2086. An in vitro study revealed that an enhanced neutrophil adhesion to hepatic endothelial cells by stimulation with the sera that were collected from the GalN-LPS-treated rats, was reduced in the presence of WEB 2086 in a dose-dependent manner. In addition, LPS, TNF-alpha, and PAF were found to enhance the neutrophil adherence to hepatic endothelial cells, which was reduced in the presence of WEB 2086. These results suggest that PAF play an important role in the GalN-LPS induced hepatic injury and that PAF receptor antagonist reduces the neutrophil adherence to hepatic endothelial cells in the liver.

Animals↗
PubMed1996

Role of macrophages in regeneration of liver.

In an attempt to clarify the role of macrophages and their mediators during regeneration of the liver, the difference of liver regeneration among C3H/HeN (LPS-responsive strain) and C3H/HeJ (LPS-resistant strain) mice was investigated. After a 67% partial hepatectomy, an increase in the weight of regenerating liver was significantly delayed in the C3H/HeJ mice, as compared with C3H/HeN mice. The number of hepatocytes labeled with antibody against PCNA reached maximum levels 48 hr after partial hepatectomy, but the PCNA labeling index in C3H/HeJ mice was 20% less than that for C3H/HeN mice. In addition, TNF-alpha activities in serum were enhanced shortly after partial hepatectomy in C3H/HeN strain mice, but were not increased in C3H/HeJ strain mice. Serum IL-6 levels were markedly enhanced in both C3H/HeN and C3H/HeJ mice, but a bimodial peak (14 and 48 hr after partial hepatectomy) was demonstrated in C3H/HeN mice, in contrast to a single peak (at 24 hr) in C3H/HeJ mice. Suppression of Kupffer cells by previous administration of gadolinium chloride in C3H/HeN mice reduced the increase in both serum TNF-alpha and IL-6 concentrations, reduced PCNA labeling index of hepatocytes by 20%, and disturbed the regeneration of the liver. Previous administration of antibody against TNF-alpha reduced the PCNA labeling index of hepatocytes by 20% after partial hepatectomy in C3H/HeN strain mice. These results suggest that LPS-responsive macrophages in the liver and their mediators, especially TNF-alpha, could partly play a role in liver regeneration.

Animals↗
PubMed1996

Protective effects of antithrombin III supplementation on warm ischemia and reperfusion injury in rat liver.

The effect of antithrombin III (AT III) supplementation on energy status, microcirculation, cytoprotection, and prostacyclin (PGI2) production during and after a period of warm ischemia of the rat liver was investigated. AT III supplementation (250 units/kg) stimulate prostaglandin I2 (PGI2) production from 1 hour after administration, with maximal production observed at 3 hours. Ischemia was induced by occluding the hepatoduodenal ligament for 30 minutes, and experiments were continued for 60 minutes after reperfusion. The rats received AT III (250 units/kg IC) 30 minutes before induction of liver ischemia (AT III group). In the AT III group, recovery of the beta-ATP/inorganic phosphate ratio measured by 31P nuclear magnetic resonance showed significant improvement (p < 0.01), and the recovery of tissue blood flow markedly improved (p < 0.01) compared to the saline-treated group (control group). Leakages of aspartame aminotransferase, alanine aminotransferase, and lactate dehydrogenase were mitigated in the AT III group (p < 0. 05). Ultrastructural alterations of sinusoidal endothelial cells were markedly reduced in the AT III group. The PGI2 level at the end of reperfusion was significantly elevated (p < 0.01) in the AT III group compared to the control group. The results of this study indicated that pretreatment with AT III significantly improved the energy status and microcirculation, as well as histologic damage, after liver ischemia and reperfusion. One of the fundamental effects of AT III might be mediated through the production of prostacyclin.

6-Ketoprostaglandin F1 alpha↗