Biomedical subjects

R Ohno

Publications and source records attributed to R Ohno.

At least 181 records · Page 10Linked to original sources

PubMed1996

[Multidrug resistance in acute leukemia].

We examined the multidrug resistance (MDR) P-glycoprotein (P-gp) on normal bone marrow (BM) cells and acute myeloid leukaemia (AML) cells, using newly devised flow cytometric multi-parameter analysis with CD33, CD34 and MRK16 monoclonal antibodies. With biotinylated MRK16 and a Streptavidin-RED670 (SA-RED670) conjugate, we succeeded in the detection of a small amount of P-gp on these cells. In normal bone marrow cells, the percentage of P-gp positive CD34+CD33-, CD34+CD33+ and CD34-CD33+ cells were 12.2 (2.2% (mean +/- standard deviation), 6.3 +/- 3.1% and 1.4 +/- 0.9%, respectively. By the more precise list-mode analysis, myeloid lineage cells showed continuously regressing P-gp expression as they maturated from CD34+CD33- to CD34-CD33+ cells. In AML cells at diagnosis, CD34+ CD33- cells expressed P-gp strongly, CD34+CD33+ cells moderately, and CD34-CD33+ cells weakly, showing the same tendency as observed in normal BM cells. Blast cells from acute promyelocytic leukemia (APL), which mainly expressed CD34-CD33+ but no detectable CD34+CD33- at diagnosis, expressed less amount of P-gp than the other subtypes of AML. P-gp expression on these three phenotypes increased in relapsed cases, especially on the CD34+CD33- subpopulation.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1996

Comparable gene structure of the immunoglobulin heavy chain variable region between multiple myeloma and normal bone marrow lymphocytes.

To characterize multiple myeloma (MM) from the viewpoint of the immunoglobulin (Ig) gene structure, we compared the transcripts of the Ig heavy chain variable region from 23 MM samples with 221 clones of the gamma, alpha and mu chain transcripts amplified by the reverse transcriptase-polymerase chain reaction (RT-PCR) from normal bone marrow (BM) cells. The usage of D and JH gene segments and the length of the N regions were the same between MM and the normal gamma, alpha and mu transcripts. Compared with the known germline VH genes, the frame work regions (FWRs) and complementarity determining regions (CDRs) of the VH segments mutated at rates of 8.3 +/- 4.7% and 15.9 +/- 7.7%, respectively, which were the same as the normal gamma and alpha (gamma/alpha) transcripts and higher than the normal mu transcripts. The replacement/silent (R/S) ratios of the mutations in FWRs and CDRs were 1.9 +/- 1.3 and 2.7 +/- 1.8, respectively, which were the same as the gamma/alpha and mu transcripts. On the other hand, we detected the clone-specific mu transcripts by RT-PCR using the primers corresponding to the each respective CDR-III and the constant region of the mu chain in three of the studied six MM samples, suggesting the involvement of a pre-switched B cell in some cases of MM. These findings suggested that the cellular origin of MM is heterogeneous, but that the Ig structure in MM reflects normal B cell maturation to plasma cell through mutation and selection.

Adult↗

PubMed1996

[A case report of subacute panencephalitis associated with specific T cells sensitized to proteolipid protein (PLP) synthetic peptides identified with rubella virus].

A 37-year-old woman was admitted to the hospital on October 4, 1991 because of fever, headache, and abnormal behavior. Although she was treated with aciclovir, she developed encephalitis, which slowly manifested itself over the next month as meningeal irritation, loss of consciousness, partial seizure, and quadriparesis. Her cerebrospinal fluid showed mild lymphocytic pleocytosis without protein elevation. Serum IgG antibody titer to rubella virus was elevated, but the rubella virus could not be detected in the cerebrospinal fluid by PCR amplification. Her consciousness level improved slowly, and by the end of November she suffered only dystonic posture of her right arm and hand. By the middle of December, there were no abnormal neurological findings except some extrapyramidal tract signs and symptoms, such as tremor and rigidity. The serum rubella virus IgG titer had fallen back into the normal range. Her illness was diagnosed as subacute panencephalitis, and she recovered completely about 5 months after the onset of the disease. The lack of rubella virus in the cerebrospinal fluid suggests that panencephalitis may not be dependent on virus replication within the central nervous system. Specific T cells sensitized to proteolipid protein synthetic peptides (PLP158-166) identified with rubella virus were detected in this case during the active stage. These observations imply that subacute panencephalitis may be dependent on an immune-mediated mechanism and that PLP-specific T cells may play an important role in pathogenesis of the disease.

Adult↗

PubMed1996

[The undergraduate medical education in neurology and the active learning in small groups].

In the undergraduate medical education of neurology, the lack of training for the application of acquired knowledge and the smaller chances for the practice of skills and the attitudinal education might lead medical students to be unconcerned about neurology. The measures for these problems introduced in Saitama Medical School were reviewed, which include the practical training for local diagnosis, the introduction to clinical medicine and the problem based learning in a manner of small group learning, respectively. Active, self-directed learning in small groups would help to improve the difficulties in current undergraduate medical education.

Education, Medical, Undergraduate↗

PubMed1995

Significant reduction of medical costs by differentiation therapy with all-trans retinoic acid during remission induction of newly diagnosed patients with acute promyelocytic leukemia. The Japan Adult Leukemia Study Group.

BACKGROUND: Differentiation therapy with all-trans retinoic acid (RA) induces more than 80% complete remission with the least complications in patients with acute promyelocytic leukemia (APL). The authors studied the cost-benefit of this new treatment modality compared with conventional chemotherapy in newly diagnosed patients with APL. METHODS: Costs were calculated retrospectively through the monthly bills of each patient to national health insurance and were compared between 36 patients treated with conventional chemotherapy in the AML-87 or AML-89 studies and 40 patients treated with all-trans RA alone or with all-trans RA plus low dose chemotherapy in the AML-92 study of the Japan Adult Leukemia Study Group who were treated at 22 university and cancer hospitals in Japan. RESULTS: Average medical costs except for antileukemic drugs during 2 months after admission were 4,164,026 yen (approximately US$46,300) in the chemotherapy group and 2,906,825 yen (approximately US$32,300) in the all-trans RA group (P < 0.0001). The difference resulted mainly from the costs of antibiotics and of platelet and erythrocyte transfusions. Average costs of antibiotics were 650,494 yen (approximately US$7,200) and 349,138 yen (approximately US$3,900), respectively (P < 0.0002), and those of platelet and erythrocyte transfusions were 1,016,190 yen (approximately US$11,300) and 633,444 yen (approximately US$7,000), respectively (P < 0.0020). CONCLUSION: During the remission induction therapy of newly diagnosed APL, all-trans RA significantly reduced medical costs. all-trans RA should be incorporated into the front-line therapy of patients with APL for medical and economic reasons.

Adult↗

PubMed1995

A randomized trial comparing interferon-alpha with busulfan for newly diagnosed chronic myelogenous leukemia in chronic phase.

A multicenter randomized study was conducted to compare the effect of interferon-alpha (IFN-alpha) with that of busulfan in newly diagnosed patients with chronic myelogenous leukemia (CML) in chronic phase. From October 1988 to October 1991, 170 patients were randomized to receive either IFN-alpha or busulfan. Of 159 eligible patients, 31 (38.8%) of 80 patients in the IFN-alpha group and 43 (54.4%) of 79 patients in the busulfan group achieved complete hematologic remission, and 38.8% in the IFN-alpha group and 43.0% in the busulfan group achieved partial hematologic remission. A complete cytogenetic response was induced in seven (8.8%) of 80 patients treated with IFN-alpha and two (2.5%) of 79 patients treated with busulfan, and a partial cytogenetic response was 7.5% (6/80) and 2.5% (2/79), respectively. The difference in major (complete and partial) cytogenetic response between the two groups was significant (P = .046). At a median follow-up of 50 months, the predicted 5-year survival rate was 54% in the IFN-alpha group and 32% in the busulfan group (P = .0290), and the predicted 5-year rate of remaining in chronic phase was 41% in the IFN-alpha group and 29% in the busulfan group (P = .1165). As compared with the patients with no cytogenetic response, the patients with any cytogenetic response (complete, partial or minor) after the IFN-alpha or busulfan treatment were significantly superior in the duration of chronic phase (IFN-alpha group; P = .0017, busulfan group; P = .0010) even after correction for the time to response using the landmark analysis. However, there was no significant difference in survival rate in the IFN-alpha group (P = .1065). There was no significant difference in survival rate (P = .3923) and the duration of chronic phase (P = .6258) between the IFN-alpha and the busulfan group in the patients with a cytogenetic response (complete, partial or minor). These results demonstrate that IFN-alpha treatment produces a significantly superior cytogenetic response and survival rate as compared with the busulfan treatment, and unexpectedly, that busulfan can also eliminate Philadelphia chromosome positive clone in a few patients who showed prolonged survival rate and duration of chronic phase.

Adult↗

PubMed1995

A study on thapsigargin-induced calcium ion and cation influx pathways in vascular endothelial cells.

To investigate Ca2+/cation entry pathway in vascular endothelial cells, we examined the effects of thapsigargin on [Ca2+]i and Mn2+ entry in cultured porcine aortic endothelial cells. Thapsigargin inhibits the activity of endoplasmic reticulum (ER, intracellular Ca2+ pool) Ca(2+)-ATPase, and stimulates Ca2+ entry from extracellular space by depleting intracellular Ca2+ pool. Cultured endothelial cells were loaded with fura-2/AM, and [Ca2+]i was measured by the ratios of fluorescence at 340/380 nm excitation, and Mn2+ entry was observed by the quenching of fluorescence at 360 nm excitation. Thapsigargin elevated [Ca2+]i in a time- and dose-dependent manner. The increase in [Ca2+]i caused by thapsigargin was lowered in Ca(2+)-free solution containing 3 mM EGTA. Verapamil (10(-5) M) and equimolar replacement of extracellular NaCl by LiCl had no effects on the maximum elevation of [Ca2+]i by thapsigargin. The increase in [Ca2+]i by thapsigargin was significantly inhibited by either NiCl2 (10(-3) M) or membrane depolarization using 50 mM KCl. Thapsigargin stimulated Mn2+ entry concomitantly with the increase in [Ca2+]i. Mn2+ entry was augmented in Ca(2+)-free solution. These results suggested that (1) the increase in [Ca2+]i by thapsigargin consisted of both Ca2+ release from ER and Ca2+ entry from extracellular space, and (2) thapsigargin also stimulated Mn2+ entry, which was interfered with in the presence of extracellular Ca2+.

Animals↗

PubMed1995

Analysis of the joining sequences of the t(15;17) translocation in human acute promyelocytic leukemia: sequence non-specific recombination between the PML and RARA genes within identical short stretches.

Molecular analysis of the t(15;17) translocation in 70 patients with acute promyelocytic leukemia (APL) confirmed that the breakpoints of chromosome 15 were located in two regions of the promyelocytic leukemia (PML) gene, mainly introns 3 and 6, whereas the breakpoints of chromosome 17 were consistently in intron 2 of the retinoic acid receptor alpha (RARA) gene. To study the reason for the clustering of the breakpoints and the underlying mechanism of the chromosomal translocation, we characterized the joining sequences of der(15) and der (17) by polymerase chain reaction in samples from eight patients with APL. There was no cluster of the breakpoints within the introns, and no consensus sequence-motif was found around them. One or nine extra nucleotides were inserted into two joining sites. There were identical stretches of one to seven nucleotides between the PML and RARA genes in the majority of the joining sequences. These data provide a potential model of the t(15;17) translocation: random DNA double strand cleavage, modification of DNA ends by enzymes including terminal deoxynucleotidyl transferase, and single strand base-pairing within identical short stretches. Furthermore, APL develops only when the PML and RARA genes are rearranged, within restricted genomic regions and a functional PML-RARA chimeric product is produced, and this might lead to a clustering of the breakpoints.

Base Sequence↗

PubMed1995

Phase I study of NKT-01.

A phase I study of NKT-01 (deoxyspergualin), which is a derivative of an antitumor antibiotic, spergualin, was performed by a cooperative study group. NKT-01 was given intravenously by 3-h infusion. The effect of single administration was studied prior to evaluation of daily administration for 5 consecutive days. In all, 5 and 33 patients with various malignancies, including leukemia, were entered into the trials of single and daily administration, respectively. In the single-administration study, all patients were evaluable and no clear adverse effect was observed at doses ranging from 20 to 320 mg/m2. In the daily-administration study, 28 evaluable patients (16 men and 12 women; median age, 55.5 years) were treated with a daily dose of 20-500 mg/m2. Toxicities such as myelosuppression, mild nausea/vomiting, anorexia, alopecia, tongue and perioral numbness, and hypotension were observed dose-dependently during or after the treatment. Grade 2 leukopenia, thrombocytopenia, and anemia were experienced at a dose of 500 mg/m2. These usually recovered to normal values by approximately 3 weeks after treatment. A pharmacokinetic analysis of single administration revealed rapid plasma clearance, with mean half-lives for the alpha and beta phases being 28 min and 6.9 h, respectively. Approximately 12% of the infused dose was excreted into the urine in unmetabolized form. The pharmacokinetic parameters obtained after 5-day administration were similar to those recorded after single administration. Concerning treatment response, a transient but significant reduction in the number of leukemic cells was observed in one patient with adult T-cell leukemia. In this study, perioral numbness, hypotension, and hematological toxicity were concluded to be dose-limiting, with the maximal acceptable dose being 500 mg/m2. The recommended dose for a phase II study of NKT-01 against solid tumors was judged to be 400 mg/m2 given daily by 3-h infusion for 5 days, every 3 weeks. In hematological malignancies, however, higher myelosuppressive schedules of administration should be investigated.

Adult↗

PubMed1995

Interaction of 5SrRNA-L5 protein complex, methionyl-tRNA, and methionyl-tRNA synthetase in the macromolecular ARS complex.

Rat liver cytosol was incubated with a trace amount of rat liver 5SrRNA which was highly labeled at the 3'-end with cytidine 3',5'-[5'-32P]biphosphate, and with [35S]methionine in the presence of ATP mixture, and then with an antibody against ribosomal protein L5. The mixture was analyzed by protein A-Sepharose chromatography. The following results were obtained. (i) The eluate with glycine-HCl buffer (pH 3.0) from the protein A-Sepharose column contained an overlapping peak of 32P- and 35S-radioactivities. In a control experiment using the same amount of 32P-labeled Escherichia coli 5SrRNA with the same specific activity, no fraction of the eluate contained 32P-radioactivity. (ii) The fractions containing both 32P- and 35S-radioactivities from the protein A-Sepharose column were crosslinked by UV irradiation. The products was subjected to PAGE, and RNA in each gel slice was eluted and purified. The fraction containing both 32P- and 35S-radioactivities was present in a region of somewhat higher molecular weight than that of 5SRNP, whereas very low 32P- and 35S-radioactivities were present in this region in the control experiment without UV irradiation. This finding suggested that [35S]methionyl-tRNA interacted with 32P-labeled 5SRNP. (iii) The fraction containing overlapping 32P- and 35S-radioactivities described above was subjected to Sephadex G-150 chromatography. The component containing both radioactivities was distributed in the region corresponding to molecular weights of 10,000 to 250,000 with a peak at about 200,000, suggesting the presence of a complex containing Met-RS (Mr 108,000), 5SRNP (Mr 74,000), and methionyl-tRNA (Mr 25,000). Furthermore, this fraction showed definite Met-RS activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acyl-tRNA Synthetases↗

PubMed1995

New flow cytometric method for detection of minimally expressed multidrug resistance P-glycoprotein on normal and acute leukemia cells using biotinylated MRK16 and streptavidin-RED670 conjugate.

To evaluate the expression of multidrug resistance (MDR) on normal and leukemia cells, we examined P-glycoprotein (P-gp) by a newly devised flow cytometric method, utilizing a biotinylated monoclonal antibody (mAb) against P-gp (MRK16), a streptavidin-RED670 conjugate (SA-RED670) and appropriate emission filters. The combination of biotinylated MRK16 (b-MRK16) and SA-RED670 resulted in higher sensitivity as compared with standard methods such as the use of streptavidin-phycoerythrin (SA-PE) conjugate. The sensitivity was examined in K562, K562/ADR, NOMO-1, NOMO-1/ADR and HL60 cells, and compared with the data obtained from reverse transcription polymerase chain reaction (RT-PCR) of mdr-1 gene. P-gp positivity on flow cytometry was 10.4%, 99.9%, 1.4%, 90.4% and 0%, respectively. Mdr-1 mRNA was well expressed in K562/ADR and NOMO-1/ADR cells, but not in NOMO-1 and HL60 cells. In K562 cells, mdr-1 was found after 40 cycles of PCR, but not 25 cycles. These data are well correlated with those from the flow cytometry. We then studied the P-gp expression on normal peripheral blood cells and acute leukemia cells. P-gp was little expressed on peripheral lymphocytes, monocytes and granulocytes. It was also little expressed on blast cells from 5 patients with acute promyelocytic leukemia (AML) and 5 acute lymphocytic leukemia (ALL) expressed P-gp at diagnosis, ranging from 8.5% to 34.5% (16.9 +/- 11.8%) and from 2.3% to 45.6% (24.0 +/- 17.8%), respectively. All 9 relapsed or refractory cases expressed P-gp, ranging from 21.1% to 99.8% (52.2 +/- 29.9%). Significant differences were found in APL, CD34-positive and relapse and refractory cases (P = 0.0006, 0.0007 and 0.0088, respectively). These results indicate that this flow cytometric analysis is useful for the evaluation of clinical MDR status and can identify a group of patients with resistant leukemia.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1995

Expression of granulocyte colony-stimulating factor receptor increases with differentiation in myeloid cells by a newly-devised quantitative flow-cytometric assay.

In order to develop a non-isotopic quantitative assay of granulocyte colony-stimulating factor (G-CSF) receptors on human or murine cells, we devised a flow-cytometric assay using cells stained with biotin-labelled G-CSF (b-G-CSF) and a streptavidin-RED670 conjugate. For quantification, we applied the Kolmogorov-Smirnov test and calculated the D value. The D value was evaluated from the degree of shift in two fluorescence profiles according to the increase of fluorescence intensity due to the specific binding of b-G-CSF to G-CSF receptors. A good correlation was observed between the number of G-CSF receptors obtained by the radioisotopic binding assay and the number calculated from the D value by the flow-cytometric assay. Then, expression of G-CSF receptors on human bone marrow cells, peripheral blood granulocytes and blast cells from patients with acute myeloid leukaemia (AML) were studied. G-CSF receptors was expressed on CD34+CD33-, CD34+CD33+ and CD34-CD33+ cells in the following order: CD34-CD33+ > CD34+CD33+ > CD34+CD33- cells, indicating that the receptors increased with maturation. The receptor levels of CD34-CD33+ cells in bone marrow were apparently lower than those of CD34-CD33+ cells in peripheral blood granulocytes. On the other hand, an abnormal expression pattern of G-CSF receptors was noted in AML blast cells.

Acute Disease↗

PubMed1995

Intracellular sodium concentration in diabetic rat ventricular myocytes.

We measured intracellular NA+ concentration ([Na+]i) of diabetic rat ventricular myocytes using sodium-binding benzofuran isophthalate (SBFI). We used diabetic rats at 8 weeks after the injection of streptozotocin (45 mg/kg i.v.). The level of [Na+]i during the control perfusion was significantly lower in diabetic myocytes than that in normal myocytes (9.2 +/- 0.4 mM v.s. 12.0 +/- 0.3 mM, p < 0.01). After the 40 min perfusion of 1 microM hexamethylene amiloride (HMA), [Na+]i decreased significantly in both groups. However, there was no difference in [Na+]i between the two groups after the perfusion of HMA. It was suggested that the lower [Na+]i in diabetic myocytes could be due to the decreased activity of Na+/H+ exchange system.

Amiloride↗

PubMed1995

Allergic reaction involving liver dysfunction and disseminated intravascular coagulation caused by a health food, Proporis.

A 43-year-old woman was hospitalized with skin eruption and liver dysfunction complicated with disseminated intravascular coagulation (DIC) after taking Proporis, a so-called health food. Her clinical course was well correlated with discontinuation and the retaking of Proporis. No other reason for the development of DIC was detected except for allergic reaction to Proporis, as demonstrated by a patch skin test. DIC subsided after the discontinuation of Proporis and treatment with gabexate mesilate and heparin. The consumption of health foods with various ingredients is recently increasing. Thus, attention should be paid to any possible serious allergic reaction related to such foods.

Adult↗

PubMed1995

Independent clones of trisomy 12 and retinoblastoma gene deletion in Japanese B cell chronic lymphocytic leukemia, detected by fluorescence in situ hybridization.

Trisomy 12 and a deletion of chromosome 13 are the most common chromosome abnormalities in patients with B cell chronic lymphocytic leukemia (B-CLL). We determined the frequencies of these abnormalities in Japanese B-CLL patients by FISH in interphase nuclei. Specimens from 42 patients were analyzed using both DNA probes specific to the centromeric region of chromosome 12 and the retinoblastoma (RB) gene. Among 42 patients, eight had trisomy 12 and 12 had the RB gene deletion. We found aberrations of trisomy 12 and the RB gene deletion in a totally different group of patients. This suggested that the trisomy 12 and the RB gene deletion occur in different clones and the presence of which in the same patient may be rare. Furthermore, the frequency of trisomy 12 (19%) found in Japanese B-CLL was lower than that in Western countries (30-35%). On the contrary, the frequency of the RB gene deletion (28.6%) was almost the same as in European B-CLL (30-35%). These results will be helpful in understanding the leukemogenesis of B-CLL.

Adult↗

PubMed1995

Comparable profiles of the immunoglobulin heavy chain complementarity determining region (CDR)-3 in CD5+ and CD5- human cord blood B lymphocytes.

It has been suggested that CD5+ B cells are closely related to the pathogenesis of autoimmune disease or chronic lymphocytic leukaemia, whereas the origin and physiological role of CD5+ B cells remain controversial. To study the molecular differences between CD5+ and CD5- B cells in terms of immunoglobulin gene structure, we sorted both subsets from new-born cord blood and analysed the complementarity determining region (CDR)-3 profiles of the immunoglobulin heavy chain (IgH) gene. The CDR-3 sequences from both CD5+ and CD5- B cells represented the same incidence and length of N-region, and the same usage of D and JH segments. When translated into amino acids, 24 of 32 clones (75%) and 25 of 37 clones (65.8%) from their respective subset were productive, and the composition of the deduced amino acids were similar between both subsets. These data suggest that CD5+ B cells are not a distinct lineage presenting a biased immunoglobulin repertoire in B cells.

Amino Acid Sequence↗

PubMed1995

[The effects of recombinant human granulocyte colony-stimulating factor on protracted neutropenia in patients with acute myelogenous leukemia. (rG.CSF Clinical Study Group)].

A clinical study to investigate the efficacy and safety of recombinant human G-CSF (rG.CSF) was performed in patients with acute myelogenous leukemia who had had protracted neutropenia. The drug was administered d.i.v. at a dose of 5 micrograms/kg. Sixty-four patients entered the study, of whom 61 patients were evaluable for safety and 58 patients evaluable for efficacy. The treatment produced an early recovery in neutrophil count in the patients who had had protracted neutropenia (< 1,000/microliters) of over 10 days. Among relapsed cases and cases showing > 20% blasts in the bone marrow, many showed blast stimulation in response to rG.CSF, suggesting difficulty in attaining complete remission by subsequent chemotherapy in such cases. The present data indicates that it is desirable to use the drug in lower-blast-count states in order to attain safe and sufficient therapeutic effects in patients with acute myelogenous leukemia who have had protracted neutropenia.

Adolescent↗

PubMed1995

[A randomized controlled study of rG.CSF in patients with neutropenia after induction therapy for acute myelogenous leukemia. (rG.CSF Clinical Study Group)].

A randomized treated/non-treated study of rG.CSF (5 micrograms/kg/d, d.i.v.) in patients with acute myelogenous leukemia was conducted to assess its efficacy on fever (> or = 38 degrees C) or documented infection after induction therapy. Of 95 patients enrolled, 46 patients were evaluable for safety and 43 for efficacy in the treated group of 47 patients while 37 of 48 patients were eligible for data analysis in the untreated group. Mare patients showed a recovery in the blood neutrophil count (to > 1,000/microliters) during rG.CSF treatment (14 days) than in the non-treated group (p = 0.039) while the number of febrile patients and duration of fever did not significantly differ between the two groups. The treatment with rG.CSF enabled an early recovery in neutrophil count in the patients with neutropenia and overt signs of infection after induction therapy, but there was no hastened allevistion of symptoms of infection in these patients.

Adolescent↗