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S Sekiguchi

Publications and source records attributed to S Sekiguchi.

At least 91 records · Page 5Linked to original sources
PubMed1997

[Flow cytometric analysis of P-glycoprotein function by rhodamine 123 dye-efflux assay in human leukemia cells].

Cells with multidrug resistance(MDR) phenotype express P-glycoprotein(P-gp) on cell membrane, which works as a drug-efflux pump with low selectivity. P-gp function can be determined microfluorometrically using the fluorescent dye rhodamine 123(Rh123), which is an artificial substrate for P-gp. In this study, we assessed P-gp function in human leukemia sublines of MOLT-3 with various magnitude of MDR phenotype using the Rh123-efflux assay. The MDR cells efficiently pumped out Rh123 outside cells in parallel with the magnitude of resistance to vincristine, while the parent MOLT-3 cells scarcely showed dye efflux. The P-gp function determined by the dye efflux assay was correlated with the degree of cell surface expression of P-gp measured by indirect flow cytometric analysis using MRK16 anti-P-gp antibody and with the amount of MDR1 mRNA (encoding P-gp) quantified by Northern blot analysis and by competitive reverse transcription-polymerase chain reaction (RT-PCR) assay. In the evaluation of 28 clinical samples obtained from patients with leukemias, 9 cases exhibited positive results Rh123-efflux. A good correlation of Rh123-efflux with MDR1 expression measured by competitive RT-PCR was observed in these samples. Since subpopulations of normal lymphocytes show low degree of P-gp function, the strict gating of leukemia cells was mandatory in the dye-efflux assay in clinical samples. Although leukemia cells could not be distinguished from normal lymphocytes in the conventional scattergram in some cases, additional staining of the former cells with specific monoclonal antibody such as CD34(labelled with PE-Cy5, a dye without interference with Rh123 fluorescence emission) enabled a selective analysis of a particular subpopulation. The Rh123 dye-efflux assay is a simple and sensitive method for the determination of P-gp expression and its function, and is particularly suitable for the analyses in the clinical laboratory.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1997

[Acute eosinophilic pneumonia associated with aspirin].

A 21-year-old man was admitted to our hospital with acute progressive dyspnea and a high fever. He had started smoking 6 weeks before admission. A chest radiograph showed diffuse infiltrates with Kerley B lines and bilateral pleural effusions. There was no evidence of infection. His condition improved rapidly and without medication. On admission the concentrations of interleukin-5 in bronchoalveolar lavage fluid and in blood were high, but they were normal one week later. Acute eosinophilic pneumonia was diagnosed. A positive result of a lymphocyte stimulation test indicated that the development of symptoms was closely associated with ingestion of aspirin. We know of no previous report of acute eosinophilic pneumonia associated with aspirin.

Acute Disease↗
PubMed1996

Decreased inducible expression of CD80 and CD86 in human monocytes after ultraviolet-B irradiation: its involvement in inactivation of allogenecity.

Ultraviolet-B (UV-B) irradiation of antigen presenting cells (APCs) modifies their allogenecity, resulting in inhibition of the proliferative response of T cells in mixed lymphocyte reaction (MLR). Costimulation by the CD28 ligand CD80 (B7/B7-1) and CD86 (B70/B7-2) plays an important role during T-cell proliferation by augmenting synthesis of interleukin-2 (IL-2) and other cytokines. In this study, we demonstrated induced expression of both CD80 and CD86 during allogeneic MLR, though human freshly isolated monocytes express CD86 constitutively with a much lower level of CD80. A monoclonal antibody (MoAb) against CD86, but not CD80, efficiently inhibited allogeneic T-cell proliferative responses stimulated with highly purified monocytes. UV-B exposure (0 to 1,000 J/m2) of monocytes inhibited the proliferation of T lymphocytes in MLR in a dose-dependent manner. Flow cytometric analysis showed that UV-B exposure of monocytes impaired the constitutive expression of CD54 (intercellular adhesion molecule-1) by 24 hours after irradiation, but the effect on CD86 was relatively less. The surface expression of CD80, CD86, CD54, and HLA-DR on monocytes was further augmented by interferon (IFN)-gamma; this cytokine-induced expression was dose-dependently reduced by UV-B irradiation. Similarly, the upregulation of these molecules following allogeneic MLR was downregulated by UV-B irradiation. UV-B irradiation of monocytes inhibited the expression of IL-2 mRNA in monocyte-stimulated allogeneic MLR. In contrast, the addition of anti-CD28 MoAb at the onset of MLR prevented, at least partially, the reduction of IL-2 mRNA. These results strongly suggest that the impairment of inducible expression of CD86 and CD80 may contribute to the reduced MLR response following exposure of monocytes of UV-B.

Antibodies, Monoclonal↗
PubMed1996

Effects of ultraviolet B irradiation on cell-cell interaction; implication of morphological changes and actin filaments in irradiated cells.

We studied the effects of ultraviolet B (UV-B) irradiation on cell-cell interactions using mouse lymphoma RMA cells and T cell hybridoma HTB-176.10. RMA cells act as stimulators by presenting H-2Kb surface antigens to HTB-176.10 cells, inducing IL-2 production in HTB-176.10 cells. Irradiating RMA cells with 1000J/m2 UV-B suppressed cell cluster formation between RMA and HTB-176.10 cells and reduced the level of IL-2 production in HTB-176.10 cells, although H-2Kb surface antigens of RMA cells were still expressed. Electron microscopic observations of irradiated RMA cells revealed that UV-B irradiation damaged cell structures, resulting in the disappearance of microvilli on the cell surface, destruction of mitochondria, vacuolation of cytoplasm and swelling of the perinuclear cisterna space. We found that these alterations were accompanied by polymerization of filamentous actin quantified by flow cytometry after NBD-phallacidin staining. Our results suggest that a target of UV-B-induced alterations is actin filaments, which support the cell morphology as the cytoskeleton, and that modification of filamentous actin inhibits interaction between RMA and HTB-176.10 cells. This underlying mechanism may account for the impaired interaction between antigen-presenting cells and T cells after transfusion with UV-B-irradiated allogeneic blood components.

Actins↗
PubMed1996

Mobilization of peripheral blood progenitor cells following CHOP treatment combined with delayed granulocyte colony-stimulating factor administration in patients with non-Hodgkin's lymphoma.

The kinetic change in peripheral blood progenitor cells (PBPC) during 3 to 6 cycles of standard CHOP regimen supported with human recombinant granulocyte colony-stimulating factor (rG-CSF) was investigated in three patients with newly diagnosed intermediate grade, diffuse large cell type, non-Hodgkin's lymphoma (NHL) without bone marrow invasion. Patients were given rG-CSF subcutaneously (2 mu g/kg/day) initiated when total leukocytes was < 3.0 x 10(9)/1. When the leukocyte count remained at >3.0 x 10(9)/1, rG-CSF was started 10 days following the prior CHOP. Treatment with rG-CSF was discontinued after the leukocyte count reached >10.0 x 10(9)/1, and CHOP was started the next day (CHOP-G regimen). The number of PBPC was monitored by clonal assay in patients 1-3. No severe leukopenia with <0.5 x 10(9)/1 of neutrophils was seen in any patient. Colony-forming unit granulocyte-macrophage (CFU-GM) significantly increased after 2-3 days of consecutive administration of rG-CSF. The magnitudes of maximum amplification of CFU-GM in patients 1, 2, and 3, were 56-fold (during 3 cycles of CHOP-G), 216-fold (during 2 cycles), and 67-fold (during 4 cycles), respectively, and the absolute numbers of the maximum CFU-GM/ml blood were 983, 7,568, 9,865, respectively. In one patient who was given 6 cycles of CHOP-G, the peak values of mobilized CFU-GM in each cycle did not substantially decrease until 6 cycles of CHOP-G had been completed. Thus, the CHOP-G regimen described here seems to be very efficient increasing the circulating CFU-GM prior to harvesting PBPC.

Adolescent↗
PubMed1996

[Isolated rupture of the ventricular septum caused by nonpenetrating trauma--a case report of operation in acute stage].

We experienced a case of the isolated ventricular septal defect due to nonpenetrating chest trauma. The patient was 22-year-old male who hit his chest with a steering wheel on car accident. The echocardiogram examined on the next day revealed a ventricular septal defect. Four days after the injury, intracardiac repair was performed. On cardiopulmonary bypass the ventricular perforation (35 x 35 mm size) located in the muscular portion near the apex was closed with a PTFE and equestrian pericardial patch. Postoperative cardiopulmonary function could improve enough to wean from IABP and respiratory support. However, the patient died on the fifth postoperative day of severe hepatic failure due to profound shock persisted after the accident.

Accidents, Traffic↗
PubMed1996

[Separation of methotrexate-polyglutamates by capillary electrophoresis and its application to the measurement of gamma-glutamyl hydrolase activity in human leukemia cells in culture].

We have applied capillary electrophoresis to the separation of methotrexate (MTX)-polyglutamates, and gamma-glutamyl hydrolase (GGH) activities in tumor cells were measured by using this new analytical method. MTX-polyglutamates were sufficiently separated in 15min by capillary electrophoresis with silica fused capillary (phi 50 microns x 75cm), being electrophoresed at 25kV and 30 degrees C in a buffer which contained 20mM sodium tetraborate, 20mM SDS and adjusted pH to 9.5. MTX-polyglutamates eluted were detected at 300nm UV. Cellular extracts obtained from the sensitive and antifolate-resistant human leukemia cell lines, MOLT-3 and K562, were incubated with MTX-glu5 at 37 degrees C for 1, 2 and 4 hr, and the amounts of the degradation products (glu1-glu4) were measured for GGH activity by capillary electrophoresis. There was no significant difference in the production of the metabolites between MOLT-3 and K562 cells (867 +/- 109 vs 799 +/- 56 pmol products/min/1 x 10(7) cells), however, the MTX-resistant MOLT-3 cells with a diminished polyglutamation of folates (MOLT-3/MTX.P-17) and the ZD1694-resistant K562 cells with the impaired membrane transport for reduced folates/MTX/ZD1694 (K562/ZD1694.C) showed decreased activities of GGH (519 +/- 52 and 680 +/- 99 pmol products/min/1 x 10(7) cells, respectively), suggesting the down-regulation of the enzyme in these antifolate-resistant cells concomitant with the intracellular substrate depletion. This study indicates that capillary electrophoresis is a rapid, cost-efficacious method with a sufficient reproducibility in the measurement of GGH activity and must be more suitable for the analysis of clinical samples than HPLC method which requires a large volume of the material.

Down-Regulation↗
PubMed1996

[A case of surgically treated hypertrophic obstructive cardiomyopathy suffering from angina pectoris during hemodialysis].

Surgical procedure for hypertrophic obstructive cardiomyopathy (HOCM) in a patient chronic hemodialysis has not been reported in Japan. This is a case report of a 61-year-old male who had been suffering from angina pectoris during hemodialysis. Cardiac catheterization showed a systolic pressure gradient of 79 mmHg at the left ventricular outflow tract and left ventriculogram demonstrated severe mitral regurgitation. He underwent mitral valve replacement and left ventricular myectomy with hemodialysis and extracorporeal ultrafiltration method during cardiopulmonary bypass. Postoperative catheterization showed a decrease of pressure gradient to 19 mmHg at the left ventricular outflow tract, and relief of angina was obtained.

Angina Pectoris↗
PubMed1996

The results of the "essential laboratory tests" applied to new outpatients--re-evaluation of diagnostic efficiencies of the test items.

We have analyzed diagnostic efficiencies of the individual "Essential laboratory test" items when these tests were applied to 520 new outpatients in the division of comprehensive medicine in a teaching hospital. The integration of these test results with history-taking and physical examination resulted in 544 primary clinical diagnoses which corresponded to the patient's illness complained and in 361 additional diagnoses unrelated to their chief complaints but found by chance by the addition of the test results. Clinical usefulness of these test items were variable depending on the disease category, demonstrating a superior diagnostic efficiency in infectious or inflammatory diseases, liver and biliary tract diseases, hematological disorders or metabolic diseases such as hyperlipidemia and diabetes mellitus, but a lesser degree of usefulness in gastro-intestinal or neurogenic diseases. Urine urobilinogen could not establish its clinical usefulness because of extremely low diagnostic sensitivity even in liver diseases. The leukocyte differential count provided confirmatory information for infectious or inflammatory diseases and was helpful for the estimation of the etiologic nature of infectious diseases. This study failed to terminate a controversy for the adoption of sialic acid instead of erythrocyte sedimentation rate (ESR) in the "Essential laboratory test" items, since the former test showed lower sensitivity, even though higher specificity, in infectious or inflammatory status than ESR. Low albumin globulin ratio (A/G) revealed equivalent diagnostic sensitivity and specificity to the elevated levels in alpha 1 and/or alpha 2 globulin fractions in infectious or inflammatory status, being helpful for the evaluation of patient's general condition at a glance. Incidental analysis for diagnostic values of cholinesterase and random blood glucose for the detection of fatty liver and diabetes mellitus, respectively, suggested that these two tests may be included in the "Essential laboratory tests". Simultaneous measurement of serum creatinine and blood urea nitrogen levels was recommended for the ambulatory screening of renal insufficiency, rather than the measurement either alone. The results in this study provide scientific bases on the usefulness of the individual test items and should be taken into account in the next version of the "Essential laboratory tests".

Adolescent↗
PubMed1996

[Clinical evaluation of hepatitis C virus RNA quantification by competitive reverse-transcription PCR].

We have quantified the hepatitis C virus (HCV) RNA by competitive reverse-transcription PCR method (Amplicor) HCV quantification monitor kit) in sera with positive HCV antibody measured by means of the second generation HCV antibody assay. Among the visitors to PL Tokyo Health Control Center for their health examination and the patients to National Defense Medical College Hospital, 123 HCV antibody-positive cases were examined. A positive but low correlation between the amount of HCV-RNA and the titer of HCV antibody (r = 0.508, p value < 0.0001) was obtained. HCV-RNA was not detectable in 19 HCV antibody-positive cases. Among them, 10 cases showed normal ALT values. In the cases with more than 1000 copies/ml of HCV-RNA, the greater the amount of HCV-RNA the higher ALT values were observed, while the titer of HCV antibody was not correlated to ALT. This study demonstrated the dissociation and low correlation between HCV-RNA amount and antibody-titers in some patients, which may recommend direct quantification of RNA for clinical evaluation of the patients with positive-HCV antibody. The quantification of HCV-RNA by such rapid and simple methods can be applicable for the determination of HCV-RNA amount in routine laboratory works.

Hepacivirus↗
PubMed1996

[Basic and clinical aspects of hepatitis virus carriers].

Among the six species of hepatitis viruses, HBV (hepatitis B virus) and HCV (hepatitis C virus) can induce persistent infection. HBV and HCV are transmitted parenterally, of which maternal transmission and transfusion-associated infection is a major route respectively. We opened the special clinic for carriers detected through blood donation, and followed them at regular intervals for their health care. The prevalence rate of HBV carriers decreased from 3.0% to 1.2% in these 10 years, and that of HCV decreased from 0.9 to 0.4% in these 4 years. Prevalence rate of HBV peaks at 50s and that of HCV peaks at 60s. Due to nearly complete screening of donated blood, post-transfusion hepatitis almost disappeared. HBV vaccine for neonates born from infected mothers reduced the new incidence of HBV carriers. In HBV carriers seroconversion of HBeAg to HBeAb occurs at teens with transient hepatitis and appearance of mutant virus. Ninety percent of the carriers remains healthy for the lifetime but some of them aggravate into chronic hepatitis leading to HCC (hepatocellular carcinoma). In HCV acute infection at adult age succeeds to chronic infection and eventually to liver cirrhosis with sporadic appearance of HCC. On the other hand, less than 50% of HCV carriers seem to be asymptomatic and do not lead to grave disease. In HBV carriers tendency to reject the virus occurs and eventually HBV is cleared in some percentage of the population. In contrast HCV does not tend to be cleared. HBsAb is a defensive antibody. In contrast HCVAb is not a defensive antibody but an infective antibody like HBcAb. DNA polymerase is a good marker of disease state in HBV, and HCV RNA is a good marker of HCV proliferation. Treatment with IFN is sometimes effective for seroconversion in HBV, and for eradication of virus in HCV.

Adolescent↗
PubMed1996

[Myocardial protective effect of rapid cooling shock at reperfusion].

Hypothermia in a heart in which coronary circulation is sustained produces positive inotropism of the myocardium. The effects on cardiac function and intracellular Ca profile of rapid cooling shock (RCS) immediately after reperfusion were evaluated in terms of their ability to inhibit the onset of myocardial stunning and to rapidly improve function. RCS administered to isolated hearts of Langendorff perfusion rats for 3 minutes induced positive inotropism after 32 +/- 4 seconds, with LV Developed Pressure (LVDP) increased a normal 120 +/- 10% (mean +/- SE, n = 16). Based on the result in which the positive inotropism was confirmed, an experiment using rats was performed as follows: after 30 minutes of ischemia at 37 degrees C, 25 degrees C or 10 degrees C, the hearts were reperfused for 1, 2 or 3 minutes and RCS was administered for 1, 2 or 3 minutes. LVDP was satisfactorily reversed early in rats treated with RCS for 3 minutes after 3 minutes reperfusion of the ischemic hearts at 25 degrees C. In this group, no significant change in Ca concentration in myocardial cells was observed at reperfusion: +/- 3% of the baseline level. Intracellular Ca overload at reperfusion and decreased intracellular Ca level, which have the effect of suppressing the CICR channel, which plays a role in Ca release into the sarcoplasmic reticulum at contraction, are important causative factors in the development of myocardial stunning, as are free radicals. RCS improved myocardial function rapidly because it inhibited change in Ca level.

Animals↗
PubMed1996

The effect of a hematopoietic-promoting factor (HPF) extracted from porcine kidney on the proliferation of human hematopoietic progenitor cells.

Hematopoietic-promoting factor (HPF), which was found in porcine kidney, has been demonstrated to act synergistically with colony-stimulating factor and erythropoietin on murine myeloid colony formation. We investigated the effect of HPF on the proliferation of human hematopoietic progenitor cells prepared from cord blood cells (CB) and peripheral blood cells (PB). HPF enhanced granulocyte colony-stimulating factor plus interleukin-3 and erythropoietin-induced colony formation, where the number of colonies were increased by 7.9-fold in CB and by 1.8-fold in PB, respectively. When we compared the effect of HPF with stem cell factor (SCF) on the colony formation derived from PB in serum-free cultures, HPF enhanced the number of erythroid burst-forming units (BFU-E) to the same extent as SCF. But the effect of HPF on promoting the growth of granulocyte-macrophage colony-forming units (CFU-GM) was less than SCF. When the enriched CD34+ cells from CB and PB were incubated in liquid culture with HPF and IL-3 for 7 days, CFU-GM was increased by 48-fold in CB, and by 25-fold in PB, respectively. The data demonstrate that HPF can potentiate expansion of hematopoietic stem cells to the same extent as SCF, and that the effects of HPF on hematopoitic stem cells differ from that of SCF.

Adult↗
PubMed1996

[The shock patients with the cardiac tamponade resulting from acute type A aortic dissection].

Twelve patients with acute type A aortic dissection were admitted at Ohta-Nishinouti Hospital from Jan. 1991 to Mar. 1994. Three of these 12 cases were in shock with cardiac tamponade on arrival at the hospital. Immediate resuscitative management was necessary for these patients, but pericardiocentasis was fruitless in the first case and emergent thoracotomy had led to the aortic rupture. While the second case was the thrombosed type aortic dissection and successfully performed pericardiocentasis, CT findings showed recanalization of the pseudolumen after a day, then we performed the urgent operation. By means of these experiences, the third case was operated quickly in spite of the thrombosed type aortic dissection, and had good result. We concluded that immediate surgical intervention should be taken to the shock patients with cardiac tamponade resulted from acute type A aortic dissection.

Acute Disease↗
PubMed1996

[Pathogenesis-screening tests for liver dysfunction in the asymptomatic patients with elevated ALT values and their diagnostic efficacies in primary care medicine].

We have evaluated the diagnostic efficacies of ultrasonography and hepatitis C virus (HCV) antibody measurement to differentiate pathogenesis of liver dysfunction in the asymptomatic adults with elevated ALT value. Among 4256 visitors to PL Tokyo Health Control Center for their health examination, 463 cases (11%) showed abnormal liver function including elevation of ALT value. Ultrasonography and HCV antibody measurement using the second generation reagent had been applied to 362 cases in order to screen the etiology of liver dysfunction. The ultrasonography succeeded to establish the diagnosis of fatty liver in 137 cases (38%) and 41 cases (11%) demonstrated positive HCV antibody. There were 4 cases with positive HBs antigen, however, it was found that their abnormal liver function was attributed to other etiology such as fatty liver and alcoholic liver dysfunction rather than chronic type B hepatitis. HCV antibody-positive cases showed higher levels of total protein, ZTT, AST, ALT, and lower levels of albumin, A/G, total cholesterol, triglyceride, gamma-GT and cholinesterase value than other cases. HCV antibody titers were not correlated to hepatic parenchymal damage estimated by ALT or cholinesterase value. Only a little correlation was observed between HCV antibody titers and HCV-RNA amounts determined by the competitive reverse transcription-polymerase chain reaction (RT-PCR) method. These results indicate sufficient diagnostic efficacies of ultrasonography and HCV antibody measurement for a pathogenesis differentiation in the asymptomatic patients with liver dysfunction, and these examinations should be employed as the first-step screening tests for the etiology determination of liver diseases in the primary care medicine.

Alanine Transaminase↗
PubMed1996

[Coronary reoperation--selection of conduit material and management of stenotic vein graft].

We have operated upon 30 cases of coronary reoperation during the past 12 years. The mean interval between the two operations was 46 months. The mean follow-up after reoperation was 61 months. The major reasons for reoperation were graft failure from technical problems in early and time-related degeneration in graft and native coronary progression in late cases. We aggressively have replaced the stenotic and obstructed vein graft with the arterial graft at reoperation since 1990. Hypoperfusion syndrome is clinical entity reported secondary to inadequate flow via the internal thoracic artery. For patients with atherosclerotic vein grafts to the LAD, the minimal manipulation of the old vein graft, adding the IMA graft to the LAD and leaving the stenotic vein graft intact appear to be safe and better procedure for long-term results. There were no operative and hospital death. Five and 10 years survival rate were 100% and 90% respectively. Five and 10 years event free rate were 92.1% and 82.9% respectively. The outcome of reoperation was satisfactory.

Adult↗