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Biomedical subjects

K Okano

Publications and source records attributed to K Okano.

At least 109 records · Page 6Linked to original sources
PubMed1996

Cytokine-induced neutrophil chemoattractant release from hepatocytes is modulated by Kupffer cells.

To clarify the role of intercellular communication in the liver during accumulation of neutrophils, the release of cytokine-induced neutrophil chemoattractant (CINC) (interleukin-8 [IL-8] related protein in rodents) by hepatocytes was investigated in the presence of Kupffer cell-conditioned medium in vitro. Kupffer cells were prepared by perfusion of rat liver with collagenase followed by centrifugation on a metrizamide gradient and were cultured in the presence or absence of lipopolysacharide (LPS). The conditioned medium was collected after 24 hours, and rat hepatocytes were cultured in the presence or absence of Kupffer cell-conditioned medium. An amount of CINC in the culture supernatant was measured by western blotting analysis and enzyme-linked immunosorbent assay (ELISA), and expression of its messenger RNA (mRNA) was assessed by the polymerase chain reaction. LPS-stimulated Kupffer cell-conditioned medium enhanced an expression of CINC mRNA in hepatocytes and increased the production of CINC by hepatocytes. Enhanced production of CINC was not shown when the Kupffer cell-conditioned medium was pretreated with heat (56 degrees C, 30 minutes). The production of CINC by hepatocytes in the presence of the LPS-stimulated Kupffer cell-conditioned medium was reduced by an antibody against interleukin 1 beta (IL-1 beta), but not by antibodies against tumor necrosis factor alpha (TNF-alpha) or LPS. These results suggest that production of CINC by hepatocytes could be regulated by IL-1 beta released from Kupffer cells, leading to neutrophil accumulation during liver injury, because this protein is a strong chemoattractant for neutrophils.

Animals↗
PubMed1996

Parathyroid hormone-related peptide in synovial fluid and disease activity of rheumatoid arthritis.

To understand the clinical role of parathyroid hormone-related peptide (PTHrP) in rheumatoid arthritis (RA), we analysed the circulatory and synovial fluid (SF) concentrations of the N- and C-terminal regions of PTHrP (N- and C-PTHrP) in RA (n = 38), osteoarthritis (OA, n = 45) and control (n = 11) subjects. The SF level of C-PTHrP was markedly higher in RA compared with control and OA groups, while no differences in circulatory C-PTHrP were present among the three groups. In contrast, the SF level of N-PTHrP was marginally higher in OA patients. C-PTHrP levels in SF correlated significantly with CRP, ESR and SF IL-1 receptor antagonist. To identify the mechanism of elevated PTHrP levels in SF, immunohistochemistry and in situ hybridization of synovial membrane (SM) were performed in each subject. Overexpression of PTHrP was identified in the sublining cells within papillary proliferated SM of RA patients only. Our results indicate that C-PTHrP produced from SM into SF reflects the disease activity in RA.

Adult↗
PubMed1996

Real-time monitoring of HCV-RNA by single tube assay kit and potential importance for predicting virological sustained response in patients with chronic hepatitis C.

In an attempt to predict virological sustained responders among patients with chronic hepatitis C after interferon therapy, HCV-RNA in serum was measured by a one tube RT-PCR assay kit using the RNA corresponding to 5 microL serum (standard assay) or 300 microL serum (enhanced-sensitivity assay). Dilution analysis revealed that sensitivity of the 'enhanced-sensitivity assay' increased by 10-100-fold when compared with a 'standard assay'. Using these assays, prospective study of interferon therapy on 38 HCV-RNA seropositive cases with chronic hepatitis (total amount 702 MU; duration of treatment 5-6 months) was performed. At the end of treatment, six were still positive and 32 became negative by the "standard assay', whereas an additional eight cases became positive (total 14 cases positive; the remaining 24 cases negative) by the 'enhanced-sensitivity assay'. Hepatitis C viral RNA state at the end of treatment remained the same 6 months later in 23 cases (61%) by a 'standard assay' and in 31 (82%) by the 'enhanced-sensitivity assay'. Of importance was that all patients (14 cases) demonstrating HCV-RNA in serum at the end of therapy, even by the "enhanced-sensitivity assay', did not show the disappearance of HCV-RNA in serum despite the long follow up. From these results, in order to improve our treatment efficacy, we should try to modify our treatment protocol to the extent that at least HCV-RNA becomes undetectable. That can be only feasible during treatment by real-time monitoring of HCV-RNA.

Adult↗
PubMed1996

Urinary excretion profile of torasemide and its diuretic action in dogs.

The plasma concentration profile, urinary excretion rate and diuretic response were studied in anaesthetized dogs after an intravenous administration of torasemide or furosemide. The urinary excretion rate of furosemide decreased rapidly after administration. The plasma concentration, which is related to the urinary excretion profile, also decreased rapidly. The diuretic response, which reflected the excretion rate, occurred rapidly after administration but lasted for a short time. The urinary excretion rate of torasemide was much lower than that of furosemide and decreased slowly after administration. The plasma concentration also decreased slowly. The diuretic response to torasemide occurred more slowly but lasted longer than the response to furosemide. These results suggest that the diuretic response profile of either diuretic depends on their urinary excretion rate, and that the difference in the diuretic response between torasemide and furosemide may be explained by the different transfer rate of the drugs from the plasma to the nephron.

Animals↗
PubMed1996

Visualization of cement exocytosis in the cypris cement gland of the barnacle Megabalanus rosa

Cementation to substrata during permanent attachment concludes the planktonic larval phase in many sessile marine invertebrates, including barnacles. However, the neural control and the mechanism of cement secretion from cement organs are poorly understood. In the present study, using isolated cement glands from cyprids of Megabalanus rosa, we have visualized cement secretion and demonstrated the stimulatory effect of dopamine and noradrenaline on such secretion. The abrupt disappearance of secretory granules and subsequent omega-figure formation indicated that exocytosis was the major mode of cement secretion. Exocytosis was localized at the apical surface of cement-secreting cells and lasted for over 30 min. Dopamine and noradrenaline also activated the directional transport of secretory granules to the sites of exocytosis. Glyoxylic acid staining provided histochemical evidence for catecholaminergic innervation to the cement glands. These results suggest that gradual, localized exocytotic secretion of cement triggered by catecholaminergic neurones is a key mechanism during permanent attachment by barnacle cyprids.

Journal Article↗
PubMed1996

[The production of high sensitive anti-myeloperoxidase monoclonal antibodies and their sensitivity and specificity].

We produced anti-myeloperoxidase(MPO) monoclonal antibodies(moAb) to detect MPO sensitivity in leukemic cells by visual light microscopy. We got seven kinds of moAbs which showed different properties to MPO. These antibodies reacted to MPO in immature and mature neutrophils, monocytes and HL-60(human myeloid leukemic cell line) by immunochemical detection using the avidin-biotin complex(ABC) staining method, but the amounts of immune complex products were significantly different at each moAb. MPO2, MPO4, MPO9 and MPO13 moAbs blocked MPO activities but MPO5 showed no such inhibition. Most of the moAbs reacted to 59kD MPO moAb using the western blotting method, while MPO4 and MPO5 reacted to both 81kD and 89kD MPO precursors. This data suggests that these moAbs are useful to demonstrate a small amount of MPO in leukemic cells.

Antibodies, Monoclonal↗
PubMed1996

[Efficacy of cefditoren pivoxil in the treatment of acute otitis media due to benzylpenicillin-insensitive Streptococcus pneumoniae].

Clinical and bacteriological studies were carried out on cefditoren pivoxil (CDTR-PI) granule in infantile purulent acute otitis media treated at general practice settings and the following findings were obtained: 1. Two hundred forty eight strains were isolated from 210 patients, almost all of which (81.1%) harbored the following two strains: Streptococcus pneumoniae (42.3%) and Haemophilus influenzae (38.8%). Among S. pneumoniae, benzylpenicillin (PCG)-insensitive S. pneumoniae, (PISP) or PCG-resistant S. pneumoniae (PRSP) was 36.2%, corresponding to 15.3% of all the isolates and found in 18% of all patients. 2. The bacteria in the middle ear discharge and the nasopharyngeal swabs were correlated with conformity rate of more than 80% with regard to Streptococcus pyogenes, S. pneumoniae and H. influenzae but no Staphylococcus aureus was detected simultaneously from the two sources in any of the patients. S. aureus and coagulase-negative staphylococci (CNS) were considered to be contaminants that were originated from the external auditory meatus at the time of sampling. 3. Frequencies of isolation of S. pneumoniae from different age groups were higher in a lower age group between 0 and 4 years and those of PISP or PRSP had the similar tendency. 4. Antibacterial activities were determined for CDTR and related oral antibiotics against the strains of S. pneumoniae and H. influenzae as representative isolates. CDTR had stronger antibacterial activities against both bacteria than the reference antibiotics. CDTR was found to be transferred into the otorrhea at a mean concentration of 0.58 micrograms/ml after single administration of CDTR-PI granule formulation at 3 mg(potency)/kg. 5. As for bacterial eradication efficacies in the middle ear cavity and the nasopharynx, eradication rates were higher than 80% in the middle ear cavity in all cases without large differences among bacterial species but eradication rate of PISP was 30% in the nasopharynx, and it was significantly lower than those of PSSP and other bacteria. 6. In view of clinical effectiveness, the efficacy rate was 89.4% and bacteriological effects was 92.2%; in view of safety, adverse reactions were; observed in 9.5% and the rate of usefulness was 89.4%. 7. From above-stated results, CDTR-PI was considered as a useful oral antibiotic for infantile acute otitis media including PISP infections.

Acute Disease↗
PubMed1996

Palmar dislocation in the metacarpophalangeal joint of the thumb--a case report.

A 19-year-old male sustained forced hyperflexion of his right thumb in a motorcycle accident which resulted in a palmar dislocation of the metacarpophalangeal joint. Open reduction was performed which confirmed the rupture of the palmar plate. Dislocation recurred post-operatively. A second operation was carried out, at which time rupture of the radial collateral ligament and dorsal capsule was recognised. Postoperative joint movement was within an acceptable range. However, radiographic examination revealed persistent subluxation. This result was thought to be related to the shape of the head of the first metacarpal bone.

Accidents, Traffic↗
PubMed1996

Reduced thyroidal uptake of inorganic iodine in liver cirrhosis.

Thyroid function was investigated in patients with liver cirrhosis. 123I uptake after four hours was significantly reduced in the liver cirrhosis group (n = 19) compared with the control group (n = 16) (2.6 +/- 0.3% vs. 5.0 +/- 0.6%, mean +/- SE, p < 0.01). There was no significant difference in the blood inorganic iodine level between the two groups, and the blood 123I count after ingestion of 123I capsules was not significantly different between the two groups. The area of the thyroid was slightly smaller in the cirrhosis group. A thyroid stimulating hormone (TSH) loading test showed no significant difference in the TSH value at any time point. The serum albumin level and prothrombin time were significantly associated with the 4-hour thyroidal 123I uptake (p < 0.01, p < 0.05, respectively). We show that the thyroidal inorganic iodine uptake was reduced in patients with liver cirrhosis and this reduction correlates with the severity of liver cirrhosis. Possible mechanisms include abnormal thyroid iodine transport capacity or reduced turnover of thyroid hormones resulting in a reduction in iodine uptake in liver cirrhosis.

Bilirubin↗
PubMed1995

Terminal differentiation of murine resident peritoneal macrophages is characterized by expression of the STK protein tyrosine kinase, a receptor for macrophage-stimulating protein.

STK, a new member of the hepatocyte growth factor receptor family, is the receptor for macrophage-stimulating protein (MSP), which acts on murine resident peritoneal macrophages. We established polyclonal and monoclonal antibodies against STK and characterized the structure of STK protein and STK expression on cells of the mononuclear phagocyte system. Western blotting showed that the STK transcript is translated into a single-chain precursor and then cleaved into a 165-kD disulfide-linked heterodimer composed of a 35-kD alpha-chain and a 144-kD beta-chain. Western blotting detected STK protein on resident peritoneal macrophages, a target of MSP, and showed that it was autophosphorylated in cells stimulated by MSP. By flow cytometric analysis using a monoclonal anti-STK antibody, we showed that STK protein is expressed on restricted macrophage populations such as resident peritoneal macrophages, but not on exudate peritoneal macrophages or mononuclear phagocytes of the bone marrow, peripheral blood, spleen, or alveoli. Resident peritoneal macrophages were classified into two fractions according to their reactivity with an anti-STK antibody and a marker antibody for macrophages: STKhigh-F4/80high cells and STKnegative-F4/80low cells. Acute exudative macrophages were all STKnegative-F4/80low, but they gradually became predominantly STKhigh-F4/80high several days after entrance into the peritoneal cavity. These results showed that after monocytes migrate into the peritoneal cavity, they undergo terminal differentiation in the peritoneal microenvironment. This is the first evidence of tissue-specific terminal differentiation of peritoneal macrophages, and this terminal differentiation can be characterized by the expression of STK receptor tyrosine kinase.

Animals↗
PubMed1995

DNA probe assay based on exonuclease III digestion of probes hybridized on target DNA.

A quantitative DNA probe assay process has been developed that uses exonuclease III. The fluorophore-labeled DNA probe is hybridized with specific sequences of the target DNA and then enzymatically digested. As these probe hybridization and digestion cycle reactions are repeated at a fixed temperature, digested probes (shortened probes) accumulate in the reaction mixture in a manner similar to a DNA polymerase chain reaction. Investigation of the digestion characteristics of the DNA probe showed that a slight digestion of a free single-stranded probe produces a large background signal, which results in low detection sensitivity. The digestion of single-stranded DNA probes is caused by double-stranded formations in the molecules. This digestion decreases and the double-stranded-specific digestion increases with increasing reaction temperature. When the reaction occurs at 45 degrees C, the association rate of the enzyme on the double-stranded DNA is 700 times faster than that on single-stranded DNA. This enables selective digestion of double-stranded DNA. The detection limit is 9 x 10(-19) mol for a M13-phage DNA.

Animals↗
PubMed1995

Sensitive assay for detection of hepatocellular carcinoma associated gene transcription (alpha-fetoprotein mRNA) in blood.

The sensitivity of RT-PCR and nested RT-PCR for detection of circulating hepatocellular carcinoma was assessed by demonstrating the tumor cell-associated gene transcription, alpha-fetoprotein mRNA, in the nuclear cells of peripheral blood. When HepG2 cells were mixed in blood, 100-1000 tumor cells/5ml of blood could be detected by RT-PCR, in contrast to 1-10 tumor cells/5ml of blood by nested RT-PCR. In addition, 2 x 10(4) copies of AFP mRNA were found in one HepG2 cell when analyzed by the quantitative nested RT-PCR assay. Thus, the nested RT-PCR assay could provide a useful tool for detecting a tiny amount of circulating tumor cells in patients with hepatocellular carcinoma presenting extra-hepatic metastasis.

Base Sequence↗
PubMed1995

Effect of splenectomy on hepatic metastasis of colon carcinoma and natural killer activity in the liver.

We have previously demonstrated that administration of killed streptococcal preparation (OK432), a biological modifier, increased the number of asialo GM1-positive cells in the liver, enhanced NK activity of hepatic mononuclear cells, and reduced the number of hepatic metastases of colon 38 adenocarcinoma that were inoculated into the superior mesenteric vein of C57BL/6 strain mice. In the present study, to clarify the role of the spleen in immune surveillance of the liver, the effect of splenectomy on hepatic metastasis of colon carcinoma and on hepatic NK activity has been examined. The number of hepatic metastasis increased in the splenectomized mice, compared with that in sham-operated mice. Administration of OK432 increased the number of asialo GM1-positive cells in the liver and enhanced NK activity of hepatic mononuclear cells in both groups, but NK activity of hepatic mononuclear cells in the splenectomized mice was less than that of the sham-operated mice. An enhanced NK activity of these cells was abolished by treatment with anti-asialo-GM1 antibody plus complement in vitro. Interleukin-2 mRNA expression was increased in the spleen 2 hr after OK432 administration and persisted until 8 hr, but was scarcely noted in the liver. On the other hand, NK activity of hepatic mononuclear cells in the asialo GM1-positive cell-depleted (previous administration of antiserum against asialo GM1) mice was enhanced after OK432 administration in the sham operated and splenectomized mice, but an enhanced NK activity in these mice was only partially or not at all abolished by treatment with anti-asialo GM1 antibody plus complement in vitro, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Chemotactic factors released from hepatocytes exposed to acetaminophen.

To clarify the mechanism of neutrophil infiltration in the liver of acetaminophen-induced hepatic injury, chemotactic factor released from hepatocytes exposed to acetaminophen has been investigated. Hepatocytes exposed to acetaminophen release nondialyzable chemotactic factor, although acetaminophen in itself inhibits chemotaxis of neutrophils. Chemotactic activity of the nondialyzable chemotactic factor was reduced after treatment with heat (56 degrees C, 30 min) or trypsin. Chemotactic activity was demonstrated at the molecular weights of around 25 and 55 kDa. Chemotactic activity of the conditioned medium was not significantly reduced in the presence of antibody against rat KC/gro protein (interleukin-8-related cytokine in rodent). Chemotactic activity of a 25-kDa factor was reduced by the antibody against the antibody against KC/gro protein, but that of a 55-kDa factor was not reduced. Immunoblot analysis revealed that the peptide reacted with antibody against rat KC/gro protein was demonstrated at a molecular weight of around 20-25 kDa, but not around 55kDa, when the conditioned medium of acetaminophen-treated hepatocytes was electrophoresed. These results suggest that hepatocytes exposed to acetaminophen release two types of chemotactic factors for neutrophils and that a major part of the chemotactic factor could be different from a member of interleukin-8 family.

Acetaminophen↗
PubMed1995

Ventromedial hypothalamic lesions induce the proliferation of gastrointestinal mucosal cells in the rat.

We reported recently that ventromedial hypothalamic (VMH) lesions increased the synthesis of DNA in the gastrointestinal tract of rats by the firing of vagus nerve activity, mainly via cholinergic receptor mechanisms. In the present study, we examined whether the mitotic response is due to proliferation of a cell population--mucosal, submucosal, or muscular layer. A monoclonal antibody to proliferating cell nuclear antigen (PCNA) has previously been shown to be capable of identifying proliferating cells. Samples of formalin-fixed gastrointestinal epithelium, taken before and after VMH lesioning, were immunostained with the anti-PCNA monoclonal antibody, and the labeling index (LI) was determined. To discriminate the effect of hyperphagia in VMH lesioned rats, we utilized the method of pair-feeding. Cell proliferation was examined by the PCNA-labeling technique 0, 1, 3, and 7 days after VMH lesioning. The increase in proliferation was confined to cells in the mucosa and did not involve the muscularis and serosa. Studies in control animals showed that the LI was higher in the small intestine than in other gut segments, and higher in the large intestine than in the stomach. The mean PCNA-LI began to increase at 1 day and continued to increase for 3 days, then decreased 7 days following the lesioning. Results indicate that the gastrointestinal mucosa is in a state of hyperproliferation after VMH lesioning.

Animals↗