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Biomedical subjects

N Ogawa

Publications and source records attributed to N Ogawa.

At least 37 records · Page 2Linked to original sources
PubMed2001

Immunosuppressive and non-immunosuppressive immunophilin ligands improve H(2)O(2)-induced cell damage by increasing glutathione levels in NG108-15 cells.

We examined the effects of FK506 and its non-immunosuppressive derivative, GPI1046, on H(2)O(2)-induced oxidative cell damage in NG 108-15 cells. Our results suggest that the protective properties of GPI1046 are equipotent with those of FK506 and may be mediated by increased intracellular concentrations of glutathione (GSH). Thus, non-immunosuppressive immunophilin ligands such as GPI1046 might be potentially for neurodegenerative diseases, particularly since they do not have serious side effects such as immune deficiency.

Cell Line↗
PubMed2001

Expression of 2-halobenzoate dioxygenase genes (cbdSABC) involved in the degradation of benzoate and 2-halobenzoate in Burkholderia sp. TH2.

Burkholderia sp. TH2, isolated from soil, utilizes 2-chlorobenzoate (2CB) and benzoate (BA) as its sole source of carbon and energy. The genes for 2-halobenzoate dioxygenase (cbdABC) from Burkholderia sp. TH2 were cloned and sequenced. The predicted amino acid sequences of all the gene products are highly similar to the cbd gene products of Pseudomonas sp. 2CBS. Disruption of the promoter region of cbdA resulted in loss of growth on 2CB and BA, indicating that these genes are involved in the growth of TH2 on these substrates. Expression of the cbd genes was analyzed by transcriptional fusion assay. The cbdS gene, a possible araC/xylS-type transcriptional regulatory gene, was shown to positively regulate the expression of cbdA. In addition, the effectors of CbdS were shown to be 2CB, 2-bromobenzoate, o-toluate (2-methylbenzoate), 2-iodobenzoate, and BA. Primer extension analysis showed that the cbdA mRNA started at two positions, 14 and 15 nucleotides upstream from the cbdA start codon, ATG. A pair of direct repeats, identical to that of the Pm promoter of the TOL plasmid, was found upstream of -35 hexamer of the cbdA promoter.

Amino Acid Sequence↗
PubMed2001

Highly sensitive determination of TS-962 (HL-004), a novel acyl-CoA:cholesterol acyltransferase inhibitor, in rat and rabbit plasma by liquid chromatography and atmospheric pressure chemical ionization-tandem mass spectrometry combined with a column-switching technique.

A quantitative bioanalytical method with excellent specificity using liquid chromatography (LC) atmospheric pressure chemical ionization-tandem mass spectrometry (APCI-MS-MS) combined with a column-switching technique has been developed for the highly sensitive and reliable determination of TS-962 (HL-004), a novel acyl-CoA:cholesterol acyltransferase (ACAT) inhibitor, in rat and rabbit plasma. The method involves protein precipitation of a 25-microl aliquot of plasma sample with eight volumes of methanol containing a deuterium-labeled internal standard, the direct injection of a methanolic supernatant into the analytical instrumentation with no sample evaporation and reconstitution steps, automated on-line clean-up on a C18 short trapping column (10 mm x 4.0 mm I.D.) followed by separation on a C18 analytical column (50 mm x 4.6 mm I.D.), and detection with APCI-MS-MS using m/z 448 ([M+H]+) as a precursor ion and m/z 178 as a product ion in a selected reaction monitoring mode. The lower limit of quantification was 1 ng/ml, and good linearity of the calibration graph was obtained in the range of 1 to approximately 490 ng/ml with excellent reliability. The developed method enabled pharmacokinetic profiles to be determined for rats and rabbits with sequential plasma collection from an individual animal.

Acetamides↗
PubMed2001

A strategy for quantitative bioanalysis of non-polar neutral compounds by liquid chromatography/electrospray ionization tandem mass spectrometry: determination of TS-962, a novel acyl-CoA:cholesterol acyltransferase inhibitor, in rabbit aorta and liver tissues.

A strategy for the sensitive and reliable quantitative determination of non-polar neutral compounds in biological matrices by liquid chromatography/electrospray ionization tandem mass spectrometry is described in the context of assay development for TS-962, a novel acyl-CoA:cholesterol acyltransferase (ACAT) inhibitor, in rabbit aorta and liver tissues. The electrospray ionization (ESI) mass spectrum of this compound with a mobile phase of water/acetonitrile did not give abundant [M + H]+ ions, but did give alkali metal cation adducts such as [M + Na]+, [M + CH3CN + Na]+ and [M + K]+ ions. The cationized species are acknowledged as unsuitable precursor ions for selected reaction monitoring (SRM) for various reasons, such as difficulty in obtaining characteristic product ions in low-energy collision-induced dissociation, and irreproducibility of the adduct-ion intensities. To overcome this problem, a solution of 3.4 mM trifluoroacetic acid in 2-propanol was added to the mobile phase as a postcolumn additive, resulting in a decrease of the undesirable adduct formation and significant enhancement of [M + H]+ ion intensity. An attempt was then made to prevent the matrix effect by employing a column-switching system, which allowed direct injection of a large volume of 2-propanolic tissue homogenate (950 microL) followed by sufficient clean-up, separation, and ESI-SRM on-line. This enabled development of a sensitive and reliable assay method for TS-962 in rabbit aorta and liver tissues in the concentration range of 5-500 ng/g wet tissue using a 25-mg aliquot of tissue sample. Application of this method to the determination of aortic TS-962 levels at 24 h after repeated oral administration of this compound (3 mg/kg) once a day for 12 weeks to 1% cholesterol-fed rabbits is also presented. Results showed that TS-962 is well distributed to both the thoracic and abdominal aorta tissues, at levels higher than the 50% inhibitory concentration value of this compound for microsomal ACAT activity from rabbit aorta.

Acetamides↗
PubMed2001

T-Cell type acute lymphoblastic leukemia following cyclosporin A therapy for aplastic anemia.

Cyclosporin A (CsA) is used to prevent rejection in transplantation and to treat autoimmune and hematologic diseases such as aplastic anemia. However, the tumor growth-promoting effect of CsA remains controversial. We report the case of a 24-year-old man who developed acute lymphoblastic leukemia of precursor-T-cell origin after 75 months of treatment with CsA for aplastic anemia. The surface antigen phenotype of his leukemic cells was CD2+, CD3+, CD5+, CD7+, CD4-, CD8-, CD10-, CD20-, CD34-, CD41-, and CD56-. Southern blot analysis revealed a monoclonal rearrangement of T-cell receptor-Jgamma nongermline fragments in HindIII digestion.

Adolescent↗
PubMed2001

Localization of annexin V in rat normal kidney and experimental glomerulonephritis.

The localization of annexin V, a calcium binding protein, was immunochemically and immunohistologically studied in experimental rat glomerulonephritis using annexin V polyclonal antibody. Plasma and urinary annexin V levels were measured by a sandwich enzyme-linked immunosorbent assay (ELISA). Urinary annexin V level, which was correlated with urinary L-lactate dehydrogenase activity, N-acetyl-beta-D-glucosaminidase activity and protein level, increased time-dependently after the injection of nephritogenic antigen (bovine glomerular basement membrane), progressively increasing to attain a peak level at 4 weeks of 51.5 +/- 11.3 ng/h. However, plasma annexin V level showed no increase during the study period. Normal kidneys showed strong staining for annexin V in distal tubules, being particularly strong in tubules of the inner stripe of the outer medulla, but could not be detected in proximal tubules. Annexin V was seen in visceral epithelial cells. Bowman's capsule of the glomerulus, the vascular endothelium of arterioles and interlobular arteries, and vascular smooth muscle. In nephritis, the lumen of distal tubules and the luminal cell membrane were deeply stained, with leakage of annexin V being observed from tubular cells. In the present study, renal annexin V was markedly excreted into urine, and its urinary level reflected the severity of damage of renal tissue and the progression of nephritis. These changes of annexin V in the distal tubule and visceral epithelial cells may be of significance in cell injury of the kidney.

Animals↗
PubMed2001

Clinical benefits of lenograstim in patients with neutropenia due to chemotherapy for multiple myeloma (MM).

The object of this study was to determine the efficacy and safety of glycosylated recombinant human granulocyte colony-stimulating factor (rHuG-CSF; lenograstim) after combination chemotherapy consisting of ranimustine, vindesine, melphalan and prednisolone (MCNU-VMP). One hundred thirty-nine consecutive patients with newly diagnosed multiple myeloma (MM) were allocated at random to a lenograstim group (n = 70) or a placebo group (n = 69). Patients were treated with two cycles of MCNU-VMP, and either lenograstim (2 microg/kg daily, s.c.) or placebo was administered from the day neutrophils decreased to less than 1.000/microl and was discontinued when neutrophils exceeded 5,000/microl. The median duration of neutropenia (neutrophils under 1,000/microl) was significantly shorter for the lenograstim group than the placebo group (2 days vs 9 days in the first cycle; 1 day vs 13 days in the second cycle). The incidence of febrile neutropenia in the first cycle was significantly lower in the lenograstim group than in the placebo group (9.2% vs 30.4%). No life-threatening infections were observed in either group. The two cycles of MCNU-VMP therapy were completed in 90.8% of the patients, and a higher average relative dose intensity (ARDI; 0.94) was achieved in the lenograstim group. The tumor response rate of the lenograstim group (57.8%) was higher than that of the placebo group (43.1%), but the difference was not statistically significant (chi2 = 2.634, df = 1, P = 0.105). Lenograstim was well tolerated, and no unexpected adverse events occurred. Lenograstim proved effective in controlling chemotherapy-induced neutropenia in MM patients under MCNU-VMP therapy.

Adjuvants, Immunologic↗
PubMed2001

Progressive cortical atrophy after forebrain ischemia in diabetic rats.

The morphological changes in the brain of diabetic rats were examined up to 8 weeks after transient forebrain ischemia produced by transient occlusion of both carotid arteries. Using histochemistry, we also examined the extent and rate of development of atrophic changes in the brain, appearance of astrocytes, activated microglia, and glucose transporter 1 (GLUT1) in streptozotocin-treated rat brains after forebrain ischemia. Atrophic changes appeared in the hippocampus in both non-diabetic-- and diabetic--ischemic groups 4 weeks after ischemia. In diabetic--ischemic rats, the atrophic changes were more severe and progressed more rapidly in the hippocampus, and were also observed in the frontal, temporal and parietal cortices, but not in any cortical areas of the non-diabetic--ischemic rats and non-ischemic--diabetic rats. We observed reduced density of GLUT1 in all cortical regions and hippocampus in ischemic-diabetic rats at 4--8 weeks, when the number of activated microglias and astroglias increased in all cortical regions. Although severe atrophic changes were observed in the gray matter, no serious injury was noted in the white matter in the diabetic-ischemic group. Our results indicate that brain ischemia in the presence of diabetes causes more severe late-onset damage culminating in brain atrophy, compared with non-diabetics.

Animals↗
PubMed2001

High cyclin E and low p27/Kip1 expressions are potentially poor prognostic factors in lung adenocarcinoma patients.

Cyclin E is an important regulator of entry into the S phase of the cell cycle. p27/Kip1 (p27) binds to cyclin E/Cdk2 complex and negatively regulates cell proliferation. We immunohistochemically examined the expression of cyclin E and p27 in 98 cases of resected lung adenocarcinoma to evaluate the prognostic significance of cyclin E and p27. Cyclin E was expressed in 16 cases (16%), and p27 was expressed in 41 cases (42%). Using Kaplan-Meier survival analysis, patients with cyclin E positive (P=0.0017) and p27 negative (P=0.011), both individually and in combination (P<0.0001), had a worse prognosis. We also analyzed the relationship of these findings to clinicopathological parameters, which revealed that cyclin E-positive, p27-negative cases had a higher Ki67 expression (P=0.012) and a higher rate of lymph node metastasis (P=0.0078) than other groups. Our results suggested that cyclin E over expression, in association with p27 reduction in particular, may potentially be a poor prognostic factor in lung adenocarcinoma patients. However, to verify the prognostic significance of these factors, a multivariate analysis of a larger number of patients should be undertaken.

Adenocarcinoma↗
PubMed2001

Effects of magnetic fields on the accumulation of thiobarbituric acid reactive substances induced by iron salt and H(2)O(2) in mouse brain homogenates or phosphotidylcholine.

In this study, we examined the effects of magnetic fields (MFs) on the generation of thiobarbituric acid reactive substances (TBARS) in the mouse brain homogenates or phosphotidylcholine (PC) solution, incubated with FeCl(3) and/or H(2)O(2). Active oxygen species were generated and lipid peroxidation was induced in mouse brain homogenates by incubation with iron ions, resulting in the accumulation of TBARS. Lipid peroxidation was induced in PC by incubation with iron ions and H(2)O(2). Exposure to sinusoidal MFs (60 Hz, 0.2-1.2 mT), symmetric sawtooth-waveform MFs (50 Hz, 25-600 mT/s), rectangular MFs (1/0.4-1/16 Hz, 3.3 mT) and static MFs (1, 5-300 mT) had no effect on the accumulation of TBARS in brain homogenates induced by FeCl(3). In contrast, when the homogenates were incubated with FeCl(3) in static MFs (2-4 mT), the accumulation of TBARS was decreased. However, this inhibitory effect disappeared when EDTA was added to the homogenate and incubated with H(2)O(2). The accumulation of TBARS in PC solution incubated with FeCl(3) and H(2)O(2) was also inhibited by the static MF. These results indicate that only static MFs had an inhibitory effect on iron-induced lipid peroxidation and the effectiveness of this magnetic field on iron ion-induced active oxygen species generation is restricted to a so called 'window' of field intensity of 2-4 mT.

Journal Article↗
PubMed2001

Molecular mechanism in activation of glutathione system by ropinirole, a selective dopamine D2 agonist.

We have previously reported that ropinirole, a non-ergot dopamine agonist, has neuroprotective effects against 6-hydroxydopamine in mice based on in vivo antioxidant properties such as the glutathione (GSH)-activating effect. In the present study, we determined that the effects of ropinirole on the level of expression of GSH-related enzyme mRNA, these enzymes were shown to regulate GSH contents in the brain. This study focused on the mechanism of GSH enhancement by ropinirole. Striatal GSH contents were significantly increased by 7-day daily administration of ropinirole. Furthermore, the expression levels of gamma-glutamylcysteine synthetase (gamma-GCS), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione S-transferase (GST) mRNA increased following daily injections of ropinirole for 7 days. In addition, ropinirole treatment for 7 days suppressed auto-oxidation in mouse striatal homogenates, in contrast to the vehicle treatment. In conclusion, ropinirole was able to suppress auto-oxidation, most probably by increasing GSH levels due to an increase of GSH synthesis. In addition, it is likely that auto-oxidation was also suppressed by the activation of GSH-regulating enzymes such as GPx, GR, and GST in the mouse striatum. Thus, our results indicate that the GSH-activating effect of ropinirole may render this dopamine agonist beneficial as a neuroprotective drug.

Animals↗
PubMed2001

Relationship between locomotor activity and monoamines following single and double transient forebrain ischemia in gerbils.

The relationship between locomotor activity and monoamine levels in gerbils after single and/or double forebrain ischemic insult was studied. Locomotor hyperactivity was observed after the first ischemic episode, but the gerbils failed to show hyperactivity after the second ischemic episode induced one week later. The monoamine levels were determined in order to clarify the biochemical basis of post-ischemic locomotor hyperactivity. Norepinephrine increased in response to first ischemic episode but remained at normal levels after the second episode of ischemia. Metabolites of dopamine and serotonin increased after both the first and second ischemic insults, which indicates that these monoamines do not play significant roles in post-ischemic locomotor activity. Therefore, increases in norepinephrine after first ischemic insult may play a role in increasing locomotor activity during the period following such an episode.

Animals↗
PubMed2001

Positive effect on T-cell regulatory apoptosis by mycophenolate mofetil.

The regulatory benefit of apoptosis (activation-induced cell death, AICD) in T cells may be impacted by immunosuppressive agents. We examined this for mycophenolate mofetil (MMF) compared with cyclosporine (CYA). Peripheral blood leukocytes (PBL) were stimulated by either Staph enterotoxin B (SEB) or by anti-CD3 plus anti-CD28. Cell division analysis (sequential reduction in carboxyflourescein diacetate succinimidyl ester, CFSE) was used to measure proliferation and determine status of different cell generations. Apoptosis was measured by annexin V staining, and FasL expression by anti-FasL antibody staining, of activated cells using flow cytometry. CSA and mycophenolic acid (MPA, the active agent of MMF) were added in titration in 3-day cultures. We found that CSA caused diminution in apoptosis but MPA increased it with SEB stimulation. The CSA effect on apoptosis was present when a more calcineurin-dependent stimulus. anti-CD3+ anti-CD28, was used but the MPA effect was less, producing a decrease only in the undivided cells. To look more directly at the differential effect on calcineurin-dependent AICD gene induction of the two agents, we measured Fas-L expression with anti-CD-3 + CD28 stimulation, and confirmed that CYA caused a major decrement in appearance of Fas-L, whereas MPA caused a converse accumulation of it. This seems to be explained by the block more distal in cell activation, resulting in a build-up of a precursor in the activation pathways. We conclude that MMF treatment may be rationale as an adjunct to calcineurin inhibitor treatment because of its converse effect on T cell regulatory apoptosis.

Apoptosis↗
PubMed2001

Reliability and validity of Kasahara's scale of melancholic type of personality (Typus melancholicus) in a German sample population.

We explored the reliability and validity of Kasahara's scale of melancholic type of personality (KMT) in a German sample population. Subjects comprised 66 patients diagnosed with an affective disorder (F3, ICD-10) and 94 controls. Concerning reliability, KMT scores showed internal consistency with Cronbach's alpha coefficients of 0.65 for patients and 0.67 for controls. The KMT items, except for number 13 in controls, showed significant item-total correlations. In a test-retest procedure, the KMT total score and individual item scores were statistically similar and correlated. These results indicate reliability of the KMT. Concerning validity, KMT scores were significantly higher in patients than in controls. By controlling the effects of age and sex, partial correlation coefficients in a comparison of KMT and Zerssen's F-List (F-List) scores were 0.40 in patients and 0.53 in controls. These results show both the constructive and concurrent validity of the KMT. Sufficient reliability and validity of the KMT were shown in this German sample population to encourage cross-cultural investigation of Typus melancholicus.

Adult↗
PubMed2001

Low-grade pulmonary myxoid sarcoma of uncertain histogenesis.

The present report describes an unusual case of low-grade pulmonary sarcoma with extensive myxoid change in a 60-year-old man. During 30 months, the tumor enlarged gradually and thereafter rapidly to 9 cm. Preoperative biopsy and cytology gave negative results. The resected mass, located at the periphery of the right upper lobe, was well circumscribed and showed gelatinous without necrosis or hemorrhage. Histologically, the tumor was composed of slightly atypical, spindle-shaped or stellate cells, which were loosely distributed within a prominent myxoid stroma. Epithelial differentiation was not seen. Lacunar structures were occasionally evident, but no cartilaginous matrix was seen. Mitotic figures were infrequent. Immunohistochemistry failed to clarify the nature of the neoplastic cells except vimentin positivity. Histochemically, the myxoid ground substance was composed of hyaluronic acid and acid mucopolysaccharide. Electron microscopy revealed no specific differentiation other than aggregates of filaments, which were seen in a number of neoplastic cells. Flow cytometric analysis of the neoplastic cells revealed a diploid pattern. These findings indicated that the neoplasm was a low-grade myxoid sarcoma; however, a definite diagnosis could not be made. The tumor might have been a variant of extraskeletal myxoid chondrosarcoma, especially considering the histochemical results.

Biomarkers, Tumor↗
PubMed2001

Neuroprotective effects of non-steroidal anti-inflammatory drugs by direct scavenging of nitric oxide radicals.

Recently, it has been reported that inflammatory processes are associated with the pathophysiology of Alzheimer's disease and that treatment of non-steroidal anti-inflammatory drugs reduce the risk for Alzheimer's disease. In the present study, we examined nitric oxide radical quenching activity of non-steroidal anti-inflammatory drugs and steroidal drugs using our established direct in vitro nitric oxide radical detecting system by electron spin resonance spectrometry. The non-steroidal anti-inflammatory drugs, aspirin, mefenamic acid, indomethacin and ketoprofen directly and dose-dependently scavenged generated nitric oxide radicals. In experiments of nitric oxide radical donor, NOC18-induced neuronal damage, these four non-steroidal drugs significantly prevented the NOC18-induced reduction of cell viability and apoptotic nuclear changes in neuronal cells without affecting the induction of inducible nitric oxide synthase-like immunoreactivity. However, ibuprofen, naproxen or steroidal drugs, which had less or no scavenging effects in vitro, showed almost no protective effects against NOC18-induced cell toxicity. These results suggest that the protective effects of the former four non-steroidal anti-inflammatory drugs against apoptosis might be mainly due to their direct nitric oxide radical scavenging activities in neuronal cells. These direct NO. quenching activities represent novel effects of non-steroidal anti-inflammatory drugs. Our findings identified novel pharmacological mechanisms of these drugs to exert not only their anti-inflammatory, analgesic, antipyretic activities but also neuroprotective activities against neurodegeneration.

Alzheimer Disease↗
PubMed2001

The prognostic advantage of preoperative intratumoral injection of OK-432 for gastric cancer patients.

To investigate, by a multi-institutional randomized trial, the prognostic significance of the augmentation of tumour-infiltrating lymphocytes (TILs) by preoperative intratumoral injection of OK-432 (OK-432 it), a bacterial biological response modifier, in patients with gastric cancer. The 10-year survival and disease-free survival were examined and analysis of the factors showing survival benefit was performed. 370 patients who had undergone curative resection of gastric cancer were enrolled in this study and followed up for 10 years postoperatively. Patients were randomized into either an OK-432 it group or a control group. Ten Klinishe Einheit (KE) of OK-432 was endoscopically injected at 1 to 2 weeks before the operation in the OK-432 it group. Both groups received the same adjuvant chemoimmunotherapy consisting of a bolus injection of mitomycin C (0.4 mg kg(-1) i.v.) and administration of tegafur and OK-432 from postoperative day 14 up to 1 year later. Tegafur (600 mg day(-1)) was given orally and OK-432 (5 KE/2 weeks) was injected intradermally for a maintenance therapy. The TILs grades in resected tumour specimens and presence of metastasis and metastatic pattern in dissected lymph nodes were examined. Multivariate analysis was performed to determine the efficacy of OK-432 it on prognostic factors. All patients were followed up for 10 years. The overall 5- and 10-year survival rates and disease-free survival rates of the OK-432 it group were not significantly higher than those of the control group. However, OK-432 it significantly increased the 5- and 10-year survival rates of patients with stage IIIA + IIIB, moderate lymph node metastasis (pN2), and positive TILs. OK-432 it was most effective at prolonging the survival of patients who had both positive TILs and lymph node metastasis. The OK-432 it group with positive TILs showed a significant decrease in metastatic lymph node frequency and in the number of lymph node micro- metastatic foci when compared to the control group. This study showed that only one time preoperative OK-432 it, particularly when it triggers TILs, is effective for reduction of regional lymph node metastasis. OK-432 it probably acts partly by eliminating micro-metastatic foci in lymph nodes. Preoperative intratumoral injection of OK-432 is technically very easy and has no serious adverse effects, so it is a promising form of neoadjuvant immunotherapy for advanced gastric cancer.

Adult↗