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Biomedical subjects

T Ochi

Publications and source records attributed to T Ochi.

At least 253 records · Page 14Linked to original sources
PubMed1992

[Effect of the tumor cell associated glycoconjugate (TCA) derived Kato III, human gastric cancer cells on autologous mixed lymphocyte reaction in patients with rheumatoid arthritis].

We have been developing a new treatment for patients with rheumatoid arthritis (RA) by using intradermal injection of carbohydrate molecule complex. Among them, tumor cell associated glycoconjugate (TCA), the membrane structure of Kato III is one of the effective molecules. We studied the immunomodulatory effect of TCA on the autologous mixed lymphocyte reaction (AMLR) using PWM-mitogen induced lymphoblasts as stimulator cells and peripheral blood mononuclear cells (PBMC) as responder cells. In the kinetic study of the AMLR, its maximum proliferation was observed on days five through seven and responding CD4 cells highly expressed HLA-DR antigen. Studied AMLR in 10 patients with RA, proliferative responses of AMLR in these patients were divided into two types, high and low AMLR types. In vitro examination of TCA on AMLR showed that TCA at a concentration of 250 ng/ml significantly suppressed the AMLR response (p less than 0.01, paired T-test) and this phenomenon was found more frequently in high AMLR type patients than in low AMLR type patients. The suppressive effect of TCA on AMLR had a tendency to correlate with the efficacy of TCA therapy in patients studied. These results suggest that TCA may play a role in regulating the function of autoreactive lymphocytes of patients with RA.

Aged↗
PubMed1992

Hepatitis virus infection (HBV and HCV) in eleven Japanese hemodialysis units.

To evaluate hepatitis C virus (HCV) and hepatitis B virus (HBV) infection in hemodialysis (HD) units, serum samples from 607 HD patients and 150 staff members at 11 HD units in Japan were collected, and were compared with those from 704 ordinary blood donors as a control. Serum samples subjected to a first generation ELISA for antibody to HCV (anti-C100-3) and were tested by ELISA for HB surface antigen (HBs-Ag), antibody to HBs-Ag, and antibody to HB core antigen (anti-HBc) as HBV markers. We also tested for HCV infection with a second generation ELISA (for antibodies to C22-3, C33c, and C100-3) in 120 HD patients and 30 staff members at 2 selected HD units. Of 607 HD patients, 104 (17%) were positive for anti-C100-3 and 221 (36%) for HBV markers, indicating a much higher prevalence of HCV and HBV infection among HD patients than among ordinary blood donors (0.9% and 18%, respectively). Of 159 patients without a history of blood transfusion, 17 (11%) were positive for anti-C100-3, showing that HCV infection can be acquired without transfusion. The incidence of anti-C100-3 varied from 0% to 53% at different HD units, and HBV markers varied from 17% to 50%. Our study detected a high prevalence of co-infection with HBV and HCV, suggesting that HCV infection may contribute to chronic liver dysfunction in HD patients. Out of 150 staff members, 3 (2%) were positive for anti-C100-3, whereas 25 (17%) were positive for anti-HBc (indicating prior HBV infection).(ABSTRACT TRUNCATED AT 250 WORDS)

Enzyme-Linked Immunosorbent Assay↗
PubMed1992

Polyamine levels in synovial tissues and synovial fluids of patients with rheumatoid arthritis.

We determined the polyamine contents of the synovial tissues from 11 patients with rheumatoid arthritis (RA), and the free putrescine levels in the synovial fluids (SF) from 10 patients with RA, 7 with osteoarthritis (OA), 5 with posttraumatic arthritis, and 3 with infectious arthritis. Putrescine levels in the synovial tissues correlated with serum C reactive protein concentration in patients with RA. Free putrescine levels in SF were significantly elevated in patients with infectious arthritis, compared with those found in RA, OA, and posttraumatic arthritis. Free putrescine levels in SF from patients with RA were significantly higher than in those with OA. Our findings suggest that polyamines may play an important role in RA.

Adult↗
PubMed1991

Cadmium-resistant Chinese hamster V79 cells with decreased accumulation of cadmium.

Cells resistant to 3 x 10(-5) M CdCl2 (Cdr cells) were isolated from cultures of Chinese hamster V79 cells by a procedure that involved stepwise increase in the concentration of Cd2+ and subsequent mass selection. Cdr cells grew as fast as wild-type cells (Cds) in medium without cadmium. Cdr cells were not cross-resistant to other divalent metal ions, such as Hg2+, Ni2+, Pb2+, and Zn2+. Both Cds and Cdr cells induced similar levels of metallothioneins (MT) in response to zinc. Depletion of glutathione (GSH) did not significantly influence the sensitivity of Cdr cells to Cd2+ but markedly enhanced the sensitivity to Cd2+ of Cds cells. Furthermore, the rate of synthesis of GSH after depletion did not differ greatly between sensitive and resistant cells. The rate of uptake of 109Cd2+ by Cdr cells was only 10-15% that by Cds cells. The difference in rates of uptake between Cds and Cdr cells was observed irrespective of the presence or absence of serum in the culture medium. These results indicate that, in this system, resistance to Cd2+ is attributable neither to increased inducibility of MT nor to increases in intracellular levels of GSH, and that only a decrease in the rate of uptake of Cd2+ contributes to the acquisition of resistance to Cd2+. Uptake of Cd2+ by cells was dependent on temperature and the rate of uptake of Cd2+ by Cdr cells was lower at all temperatures examined than the rate of uptake by Cds cells. Cycloheximide did not suppress the uptake of Cd2+, suggesting that uptake does not require synthesis of cell proteins de novo. Preincubation of cells with N-ethylmaleimide suppressed the uptake of Cd2+ to some extent, a result that suggests the involvement of surface SH groups in the uptake of Cd2+ by these cells.

Animals↗
PubMed1991

Endoscopic manometry of the sphincter of Oddi and pancreatic duct in patients with papillary stenosis.

The function of the sphincter of Oddi (SO) in patients with papillary stenosis was evaluated using endoscopic manometry to determine its possible contribution to pancreatic dysfunction. A total of 30 patients with papillary stenosis were divided into two groups according to the pattern of narrowing of the sphincter zone observed in ERCP studies: group A, a mild form, and group B, a severe form. Group C (control) comprised 12 subjects with no abnormality of the pancreas or biliary system. The SO contraction pressure was significantly higher in group A (115.1 mmHg) than in groups B (79.2) and C (91.1). The SO basal pressure in groups A (11.5 mmHg) and B (10.3) was significantly higher than in group C (5.8). The pancreatic duct pressure in group A (15.5 mmHg) was significantly higher than in group C (9.7), while group B (11.1) showed an intermediate value. The increase in pancreatic duct pressure following intravenous secretin was significantly greater in groups A and C than in B. The BT-PABA test in groups A and C revealed a normal value in contrast to group B. A significant correlation was observed between these two factors. The function of both the SO and the pancreas thus appears to be abnormal in patients with severe narrowing of the SO and papillary stenosis.

Adult↗
PubMed1991

Effects of hydrogen ion on the changes in adenosine production in the isolated rat heart perfused at a constant flow system.

This study was designed to clarify the relationship between the change in H+ and the nucleoside concentration at a constant coronary flow rate using a Langendorff system. Wistar rat hearts were perfused with Krebs-Henseleit solution (control, pH 7.4) modified to be either acidotic or alkalotic. Coronary perfusion pressure (CPP), left ventricular pressure, and myocardial oxygen consumption were decreased in the acidotic perfusate. On the other hand, these parameters increased in the alkalotic perfusate. Adenosine production in the acidotic perfusate significantly decreased while it significantly increased in the alkalotic perfusate. Furthermore, there was a significant positive correlation between both the percent change in adenosine production and the percent change in CPP in acidosis and alkalosis. It is suggested from these results that the hydrogen ion affects the adenosine metabolism and that the change in coronary blood flow by H+ is at least partly regulated by adenosine.

Acid-Base Equilibrium↗
PubMed1991

Arthroscopic stapling for detached superior glenoid labrum.

Superior labral tears of the shoulder involve the biceps tendon and labrum complex which may be detached, displaced inferiorly, and interposed between the glenoid and the humeral head. We have treated ten young athletes with painful shoulders due to this lesion by arthroscopic stapling. Arthroscopy at the time of staple removal, after three to six months, showed that all the lesions had been stabilised. Clinical review at over 24 months showed an excellent or good result in 80%. The two relative failures were due in one to residual subacromial bursitis, and the other to multidirectional shoulder instability. Arthroscopic stapling can restore the shoulder anatomy, and it is recommended for active adolescent athletes with this lesion.

Adolescent↗
PubMed1991

Facs analysis of myeloid differentiation stages in epiphyseal bone marrow, adjacent to joints affected with rheumatoid arthritis.

To analyze the differentiation stages of myeloids statistically, we adopted a two-color FACS system and used appropriate monoclonal antibodies belonging to CD15, CD16 and CD11b. By using HL60 treated with DMSO or human bone marrow MNCs from patients with rheumatoid arthritis, it was proved that with this system, myeloids could be clearly separated according to differentiation stages. Furthermore, the number of myeloids at certain stages of differentiation in the epiphyseal bone marrow of patients with RA or OA was measured. Nine of 15 samples from RA patients showed immature and relatively mature myeloids, while none of the 8 OA samples did. When the proportions of myeloids in epiphyseal bone marrow MNCs were compared with the clinical features, disease subsets in RA and the degree of synovitis, seemed to be important factors for abnormal myelopoiesis.

Adult↗
PubMed1991

Synthesis of [carbonyl-14C]sparfloxacin.

A new antimicrobial quinolone, sparfloxacin (5-amino-1-cyclopropyl-7- (cis-3,5-dimethyl-1-piperazinyl)-6,8-difluoro-1,4-dihydro-4-oxoquinoline -3- carboxylic acid, AT-4140; CAS 110871-86-8), was labeled by 14C for studies of disposition and metabolism. Ethyl pentafluoro[carbonyl-14C]benzoylacetate (I) was reacted with ethyl orthoformate, cyclopropylamine and then potassium tert-butoxide to give a quinolone intermediate (IV). A benzylamino derivative (V) obtained by condensation of IV and benzylamine was subject to catalytic hydrogenolysis and hydrolyzed to give the carboxyl derivative (VII), which was condensed with cis-2,6-dimethylpiperazine to form [carbonyl-14C]sparfloxacin. The average yield of 3 preparations was 41.5% and specific activities were 310.8-366.3 MBq (8.4-9.9 mCi)/mmol. Both chemical and radiochemical purities were greater than 99%.

Chromatography, Thin Layer↗
PubMed1991

Effect of early synovectomy on the course of rheumatoid arthritis.

Ninety-one patients with rheumatoid arthritis were retrospectively assigned to 3 subsets according to the number of joints with erosion (NJE). The subsets were least erosive (LES); more erosive (MES); most erosive involving multilating disease (MUD). In the early stages of disease the subsets were distinct (p less than 0.001) regarding mean values of annual reduction of carpal height (delta CHR) and serum Clq levels. Patient assessment (radiographic and clinical) continued to deteriorate in the MES and MUD subsets over the 1-5 year interval after synovectomy. Apparent stabilization of knee disease in the LES subset may be a feature of this subset rather than a result of synovectomy. Although synovectomy may offer short term symptomatic relief, we found no evidence that it retards the bony destruction or the disease process.

Adult↗
PubMed1990

Effects of an organic hydroperoxide on the activity of antioxidant enzymes in cultured mammalian cells.

As a basis for an evaluation of the role of the cellular antioxidant defense system against oxidative stress, the effects of an organic hydroperoxide, tertiary-butyl hydroperoxide (t-BuOOH), on the activity of antioxidant enzymes were investigated in cultured Chinese hamster V79 cells. Incubation of cells with t-BuOOH for 1 h significantly increased the activity of Cu-Zn superoxide dismutase (SOD) up to a level 1.4 times that of control cells. In contrast, the activities of catalase and glutathione reductase (GSSG-Rx) were not affected, while the activity of glutathione peroxidase (GSH-Px) was inhibited to a significant extent by t-BuOOH. Hydrogen peroxide also inhibited GSH-Px activity but its potency in this regard was somewhat lower than that of equimolar amount of t-BuOOH. Earlier studies demonstrated that t-BuOOH-induced cytotoxicity, single strand breaks (ssb) in DNA and structural aberrations in the chromosomes of V79 cells can be suppressed almost completely by an iron chelator o-phenanthroline. However, the iron chelator did not suppress the t-BuOOH-induced inhibition of GSH-Px activity. Likewise, a diffusible scavenger of free radicals, butylated hydroxytoluene (BHT) did not affect the hydroperoxide-induced inhibition of the enzymatic activity. These results suggest that a mechanism other than iron-mediated radical reaction is involved in the inhibition of GSH-Px activity by t-BuOOH. Modulation of the activity of antioxidant enzymes by the oxidative agent diamide was very similar to that by t-BuOOH. Inhibition of GSH-Px activity by t-BuOOH was reversible and the reduced activity returned to pre-inhibition levels within 1-2 h of post-treatment incubation. A mechanism for the inhibition of GSH-Px by t-BuOOH is discussed with reference to the oxidation of selenocysteine residues which results in perturbation of the normal catalytic cycle.

Animals↗
PubMed1990

Theophylline inhibits isoproterenol-induced coronary dilatation in the isolated perfused rat heart.

To study the role of endogenous adenosine in coronary dilatation induced by beta-adrenergic stimulation, isolated rat hearts were perfused at a constant flow rate. Perfusion of the heart with isoproterenol caused increases in the heart rate, left ventricular developed pressure, coronary dilatation, and release of adenosine and its degradation products. Theophylline inhibited isoproterenol-induced coronary dilatation without any significant effects on other contractile properties such as heart rate and left ventricular developed pressure. Coronary dilatation induced by exogenous adenosine was also inhibited by theophylline. These results suggest that beta-adrenergic stimulation induces coronary vasodilatation not only through direct beta-adrenergic responses, but also through increases in extracellular adenosine.

Adenosine↗
PubMed1989

Differential effects of glutathione depletion and metallothionein induction on the induction of DNA single-strand breaks and cytotoxicity by tert-butyl hydroperoxide in cultured mammalian cells.

Induction of DNA single-strand breaks (ssb), their resealing and cytotoxicity by tert-butyl hydroperoxide (t-BuOOH) were investigated in cultured Chinese hamster V79 cells. The effect of the depletion of cellular glutathione (GSH), iron chelation and induction of metallothionein (MT) on these parameters was studied. t-BuOOH in a concentration range of 0.02-0.5 mM induced DNA ssb in a dose-dependent fashion. Strand breakage increased as a function of time up to 1 h. Divalent iron chelator o-phenanthroline suppressed markedly the induction of DNA ssb while the trivalent iron chelator desferrioxamine had no effect. GSH-depletion increased cytotoxicity of t-BuOOH. In contrast, the depletion of GSH did not affect the efficiency of formation of DNA ssb by t-BuOOH and the rate of resealing of the DNA damage. The induction of MT did not influence the efficiency of formation of DNA ssb by t-BuOOH. In summary, while GSH depletion and MT induction affected the formation of DNA ssb and cytotoxicity differently divalent iron was required for both. Therefore, appears likely that DNA breakage and cytotoxicity by t-BuOOH are caused by independent mechanisms.

Animals↗
PubMed1989

Effects of tert-butyl hydroperoxide on promotable and non-promotable JB6 mouse epidermal cells.

Oxidants and agents that induce a cellular prooxidant state can act as carcinogens. We compared the effect of tert-butyl hydroperoxide (Bu-OOH) on DNA strand breakage, poly ADP-ribosylation of chromosomal proteins and the expression of the proto-oncogenes c-fos and c-myc between non-promotable clone 30 and promotable clone 41 of mouse epidermal cells JB6. These pathophysiological effects of oxidants are mechanistically related. Bu--OOH caused more DNA-strand breakage at high concentrations and more extensive poly ADP-ribose accumulation in clone 30 than in clone 41, in reactions which require intracellular free iron. Clone 41 exhibited constitutive c-myc expression while c-fos mRNA was very low in untreated cultures of both clones. Low concentrations of Bu-OOH induced c-myc and more strongly c-fos in clone 41. Both proto-oncogenes were strongly induced in clone 30. Our results allow insights into the mechanisms of action of a typical organic hydroperoxide in JB6 cells. However, they do not uncover the reasons for the differential promotability of the two JB6 clones by oxidants beyond the implication of the constitutive expression of c-myc in promotable clone 41.

Animals↗
PubMed1989

Effects of iron chelators and glutathione depletion on the induction and repair of chromosomal aberrations by tert-butyl hydroperoxide in cultured Chinese hamster cells.

The effects of iron chelators and glutathione (GSH) depletion on the induction of chromosomal aberrations by tert-butyl hydroperoxide (t-BuOOH) were investigated in cultured Chinese hamster V79 cells. t-BuOOH in a concentration range of 0.1-1.0 mM induced chromosomal structural aberrations, consisting mainly of chromatid gaps and breaks, in a dose-dependent fashion. The divalent iron chelator o-phenanthroline almost completely suppressed the formation of chromosomal aberrations while the trivalent chelator desferrioxamine was less effective. GSH depletion did not affect the formation of chromosomal aberrations and DNA single-strand breaks (ssb) by t-BuOOH. DNA ssb by 0.5 mM t-BuOOH were repaired within 60 min of treatment in both GSH-depleted (GSH-) and non-depleted (GSH+) cells. In contrast, chromosomal aberrations increased a little during the 60 min after treatment in both GSH- and GSH+ cells. The aberrations were then repaired in GSH+ cells but those in GSH- cells were maintained to a great extent during 20 h of post-treatment incubation. These results indicate that divalent iron mediates the induction of chromosomal aberrations by t-BuOOH. That t-BuOOH-induced chromosomal aberrations remain even after DNA ssb were repaired suggests involvement of other lesions than DNA ssb in the formation of chromosomal aberrations by the hydroperoxide.

Animals↗
PubMed1989

Cytotoxicity of an organic hydroperoxide and cellular antioxidant defense system against hydroperoxides in cultured mammalian cells.

The cytotoxicity of an organic hydroperoxide, tert-butyl hydroperoxide (t-BHP), was evaluated by inhibition of cell growth and of colony formation in cultured Chinese hamster V79 cells depleted or not depleted of cell glutathione (GSH). The hydroperoxide was cytostatic as shown by a marked decrease of mitotic cells, hence with a very low ability to form a colony. By depletion of GSH in the cells a killing effect of the hydroperoxide appeared. Iron chelation by O-phenanthroline markedly suppressed both inhibition of cell growth and of colony formation by t-BHP, indicating participation of divalent iron in the induction of cytotoxicity. Likewise, the pretreatment of GSH-depleted cells with cysteamine, an effective radical scavenger but without action as an electron donor in GSH peroxidase (GSH-Px) reaction, partly suppressed t-BHP-induced cell growth inhibition. These results suggest involvement of iron-catalyzed radical reaction in the induction of cytotoxicity by t-BHP. The inhibition of incorporation of tritiated thymidine and uridine by t-BHP was a little more sensitive than inhibition of leucine incorporation. GSH depletion evenly enhanced inhibition of incorporation of those precursors by t-BHP. The sensitivity to t-BHP of the cells with increased activity of GSH-Px by 1.5-2 times of control, which was achieved by treatment with 60 nM Na2SeO3, was not different from that of the cells with normal activity of the enzyme. On the other hand, t-BHP selectively inhibited GSH-Px activity without effect on glutathione reductase activity. These observations suggest that the cellular antioxidant system can not efficiently play a protective role against exogenous hydroperoxides and also that the increased cytotoxicity of t-BHP by GSH depletion is due strongly to a decrease of cell GSH as a radical scavenger than as an electron donor in GSH-Px reaction.

Animals↗