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Biomedical subjects

S Misawa

Publications and source records attributed to S Misawa.

At least 109 records · Page 6Linked to original sources
PubMed1995

Synergistic effects of stem cell factor and interleukin 6 or interleukin 11 on the expansion of murine hematopoietic progenitors in liquid suspension culture.

The synergistic effects of stem cell factor (SCF) in combination with other growth factors including interleukin (IL)-6, IL-11, IL-3, GM-CSF, G-CSF, IL-1 alpha and interferon-gamma (IFN-gamma) on the expansion of murine hematopoietic progenitors were studied in a short-term liquid suspension culture system. Bone marrow (BM) cells obtained 2 days after 5-fluorouracil (5-FU) injection were cultured for up to 18 days in serum-containing and serum-free cultures in the presence of combinations of various cytokines. The numbers of nucleated cells, total colony-forming cells (CFC), mixed-colony forming units (CFU-Mix) and high-proliferative potential colony-forming cells (HPP-CFC) before and after liquid suspension cultures were measured in the presence of different combinations of cytokines. Combinations of SCF with IL-11, IL-6 or IL-1 alpha markedly increased the numbers of total CFC, CFU-Mix and HPP-CFC. A combination of SCF and IL-3 also expanded the number of total CFC; however, the fold increase was smaller than those of SCF plus IL-11, IL-6 or IL-1 alpha. Three or four factor combinations including SCF with IL-3, IL-6 and IL-11 did not yield increased numbers of total CFC over that supported by SCF plus either IL-6 or IL-11. The addition of IFN-gamma to the culture containing SCF plus IL-11 resulted in a decrease of the expansion efficiency. However, this difference is not statistically significant. In contrast, the addition of IFN-gamma to the cultures containing SCF plus IL-6 did not affect the expansion efficiency. Interestingly, the addition of IL-1 alpha in the culture containing SCF plus IL-3 significantly increased the number of HPP-CFC over that supported by SCF plus IL-3 (p < 0.01). In contrast, IL-1 alpha did not significantly affect the expansion efficiency in the presence of SCF plus IL-6 or IL-11. These results suggest that combinations of SCF plus either IL-6 or IL-11 or a combination of SCF, IL-3 and IL-1 alpha can most effectively expand murine hematopoietic progenitors derived from day-2 post-5-FU BM cells in vitro.

Animals↗
PubMed1995

Neurofibromatosis 1 gene (NF1) mutation is a rare genetic event in myelodysplastic syndrome regardless of the disease progression.

Neurofibromatosis 1 gene (NF1) is a tumor suppressor gene and the product of which down-regulates Nras protein by its GTPase activating protein-related domain (NF1-GRD). Although the incidence of NF1 mutation was reported to be rare in the chronic phase of myelodysplastic syndrome (MDS), there have been no previous reports on its configuration in patients showing the disease progression. We examined NF1 in 50 patients with MDS including 9 who had progressed to more advanced stages and 16 to acute leukemia. Six patients had an Nras mutation. We carried out allele specific restriction analysis (ASRA) to detect a mutation at the first nucleotide A of codon 1423 (AAG), a mutational hot spot. We also employed a polymerase chain reaction mediated single strand conformation polymorphism (PCR-SSCP) method to confirm the result of ASRA and to detect a point mutation in other sequences of FLR exon. In consequence, ASRA disclosed wild type configuration and PCR-SSCP showed no aberrant band in any sample examined whether the samples harboured an Nras mutation or not. We conclude that NF1 mutation does not play a crucial role in the development and the progression of MDS.

Base Sequence↗
PubMed1995

Double mutations of the N-ras gene in a patient with acute myelomonocytic leukemia.

We report a patient with acute myelomonocytic leukemia (AMMoL) who showed two independent point mutations of the N-ras gene at codons 12 and 13. Longitudinal analysis revealed that one mutation at codon 13 was detectable throughout his disease course and the other at codon 12 emerged as a second mutation 14 months after the diagnosis was made, at the refractory stage. Cloning to vector and subsequent sequencing confirmed that these mutations occurred in different alleles. Chromosome findings showed a simple abnormal karyotype at presentation and further karyotypic aberrations during his disease course, concomitantly with the second mutation of the N-ras gene. These findings revealed a close relationship among the disease progression, karyotypic evolution and a newly-appearing N-ras mutation.

Aclarubicin↗
PubMed1995

Characterization of a 14q+ marker chromosome in philadelphia chromosome positive acute lymphoblastic leukemia by DNA analysis and fluorescence in situ hybridization.

We report a case of precursor-B acute lymphoblastic leukemia (ALL) with the Philadelphia chromosome (Ph) and a 14q+ chromosome whose additional material was a part of the long arm of der(9)t(9;22). A minor population carrying the standard Ph translocation without the 14q+ was also observed at the first presentation. The translocation of the BCR gene from chromosome 22 to the subtelomeric region of the 14q+ was confirmed by fluorescence in situ hybridization (FISH) using a yeast artificial chromosome (YAC) clone containing the BCR gene. The breakpoint of chromosome 14 could not be determined exactly but probably was at 14q24 or 14q32 by conventional chromosome analysis. Nevertheless, FISH using a YAC clone containing the human immunoglobulin heavy chain (IgH) gene locus, Southern blot, and pulsed-field gel electrophoresis (PFGE) analyses with IgJH probe, and loss of heterozygosity analysis at the alpha 1-antitrypsin (AT) gene locus showed lack of involvement of the IgH gene in the 14q+ and more centromeric breakage than the alpha 1-AT locus at 14q32.1. Thus, the formation of the 14q+ seemed to be a secondary genetic event after the Ph translocation and presumably played a minor role in the pathogenesis of B-cell malignancy in this case.

Base Sequence↗
PubMed1995

Anti-tumor activity of arginine deiminase from Mycoplasma argini and its growth-inhibitory mechanism.

Two kinds of arginine deiminase (AD, EC 3.5.3.6) were purified from cell extracts of Mycoplasma arginini (a-AD) and Mycoplasma hominis (h-AD), and their enzymic properties and anti-tumor activities were compared. The a-AD enzyme strongly inhibited the growth of mouse hepatoma cell line MH134 in vitro, and its concentration required for 50% growth inhibition (IC50) was estimated to be about 10 ng/ml. The IC50 value of h-AD against the same cell line was estimated to be about 100 ng/ml, due to its low enzyme activity under the physiological pH condition, i.e., pH 7.4. These results show that the reaction pH profile of the a-AD was superior to that of the h-AD as an anti-tumor enzyme. Moreover, the effects of L-arginine metabolism-related substances on the anti-tumor activity of the a-AD were examined to study the growth-inhibitory mechanism of this enzyme. The addition of 2 or 4 mM L-arginine restored, in a dose-dependent manner, the growth of mouse MH134 hepatoma and Meth A fibrosarcoma cell lines that had been inhibited by 20 ng/ml of the a-AD. The addition of 2 or 4 mM L-ornithine, which is biosynthesized from L-arginine in the urea cycle and is the starting material in the polyamine-biosynthesis pathway, also partially restored it in a dose-dependent manner. These results indicate that the tumor cell growth inhibition caused by a-AD originates from the depletion of the essential nutrient L-arginine, and that the resulting block of the polyamine-biosynthesis pathway is involved in part in the inhibitory mechanism.

Amino Acid Sequence↗
PubMed1995

Hemizygous expression of the wild-type p53 allele may confer a selective growth advantage before complete inactivation of the p53 gene in the progression of chronic myelogenous leukaemia.

We analysed the expression of the p53 gene in various clinical phases of chronic myelogenous leukaemia (CML) by quantitative reverse transcriptase (RT) polymerase chain reaction (PCR). Hemizygous expression of the wild-type p53 allele was observed in two samples showing the loss of one p53 allele, and affected p53 expression was associated with p53 allelic loss rather than the clinical phase of CML. In four patients with CML showing p53 inactivation, we performed a detailed sequential analysis of p53 allelic loss, p53 mutation and expression from the onset of the disease to the patients' death. Consequently, we demonstrated that the loss of a wild-type p53 allele preceded mutation of the remaining allele, and that cells hemizygous for the wild-type p53 allele dominated those with both wild-type alleles, then were replaced by cells with complete p53 inactivation. These observations indicate that not only complete p53 inactivation but also hemizygous expression of the wild-type p53 allele may confer a selective growth advantage, and that the former is implicated in a more malignant phase than the latter. Alternatively, the inactivation of another undefined anti-oncogene on chromosome 17p may allow selective growth before the p53 mutation occurs.

Alleles↗
PubMed1995

Transport of nattokinase across the rat intestinal tract.

Intraduodenal administration of nattokinase (NK) at a dose of 80 mg/kg, resulted in the degradation of fibrinogen in plasma suggesting transport of NK across the intestinal tract in normal rats. The action of NK on the cleavage of fibrinogen in the plasma from blood samples drawn at intervals after intraduodenal administration of the enzyme was investigated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting analysis with an anti-fibrinogen gamma chain antibody. The 270 kDa fragment carrying antigenic sites for the binding of the anti-fibrinogen gamma chain antibody appeared within 0.5 h and was then degraded gradually to a 105 kDa fragment via a 200 kDa fragment. This suggests that fibrinogen was degraded to a 105 kDa fragment via several intermediates (270 and 200 kDa). In parallel with the degradation process, plasma recalcification times were remarkably prolonged NK was also detected in the plasma from blood samples drawn 3 and 5 h after administration of the enzyme by SDS-PAGE and Western blotting analysis with an anti-NK antibody. The results indicate that NK is absorbed from the rat intestinal tract and that NK cleaves fibrinogen in plasma after intraduodenal administration of the enzyme.

Animals↗
PubMed1995

Changes in the metabolism of three model substrates catalysed by different P450 isozymes when administered as a cocktail to the carbon tetrachloride-intoxicated rat.

1. Caffeine (CA) metabolism in animal and man is mainly catalysed by P4501A2. Lidocaine (LID) and phenytoin (PHT) are metabolized by P4503A2 and 2B1/2 in animals and 3A4 and 2C9 in man, respectively. 2. We investigated the possibility of predicting liver damage from changes in blood concentrations after simultaneous i.v. administration (cocktail study) of the three probe drugs CA (10 mg/kg), LID (4 mg/kg) and PHT (4 mg/kg), and their main metabolites, paraxanthine (PX), monoethylglycinexylide (MEGX) and 5-(p-hydroxyphenyl)-5-phenylhydantoin (p-HPPH) respectively. 3. The metabolism of CA, LID and PHT and production of their metabolites (PX, MEGX and p-HPPH) in the carbon tetracholride (CCl4 0.25 and 0.5 ml/kg)-treated rat were reduced in comparison with the control group. 4. The ratios (PX/CA and p-HPPH/PHT) of CA and PHT to the serum levels of the their metabolites 2 h after i.v. administration of three drugs to the CCl4-treated rat were significantly reduced. 5. The correlation coefficients among CLs of CA, LID and PHT, and the PX/CA and p-HPPH/PHT ratios in rat pretreated with different doses of CCL4 are very high. 6. These results suggest that different estimates of hepatic oxidizing capacity, catalysed mainly by P4501A2, 2C and 3A, may be related to the extent of liver disease in the CCl4-intoxicated rat. Therefore a 'cocktail' is not in fact needed to assess hepatic damage in the CCl4-intoxicated rat.

Animals↗
PubMed1995

Chromosome 17 abnormalities and inactivation of the p53 gene in chronic myeloid leukemia and their prognostic significance.

We have reviewed all the relevant studies on the loss of the short arm of chromosome 17 (17p) and inactivation of the p53 gene in chronic myelogenous leukemia (CML) in an attempt to clarify their roles in the progression of CML. Loss of a 17p (hemizygous 17p) and p53 inactivation emerged as the disease progressed and were closely associated with each other. About half of the cases with loss of a 17p, however, did not show p53 inactivation. In these cases loss of a 17p preceded p53 inactivation, which suggested that either reduction of the p53 gene dosage or inactivation of another tumor-suppressor gene on 17p might contribute to the disease progression. Both loss of a 17p and p53 inactivation may serve as poor prognostic factors but the prognostic significance of the former only emerged when metaphase cells with loss of a 17p were dominant amongst the total cell population analyzed.

Blast Crisis↗
PubMed1995

Pressor effect of recombinant human erythropoietin: results of ambulatory blood pressure monitoring and home blood pressure measurements.

We investigated whether treatment of anemic hemodialysis patients with a low dose of recombinant human erythropoietin (erythropoietin) for a short period would increase their blood pressure. Ambulatory blood pressure monitoring and home blood pressure measurements were used to detect minute increase in blood pressure. Thirty-two patients with a hematocrit of 25% or less received erythropoietin at the dose of 4500 IU/week, by the intravenous route for 8 weeks. Erythropoietin increased the hematocrit from 20.9 +/- 2.1 to 26.2 +/- 2.1%. Erythropoietin elevated mean ambulatory blood pressure by 5 mmHg or more in two-thirds of patients (n = 20; pressor group), while it elevated home mean blood pressure by 5 mmHg or more in one-third of patients (n = 11). An increase in clinic mean blood pressure by more than 5 mmHg was observed only in one-fourth of patients (n = 7). Circadian variation of blood pressure (nocturnal fall and diurnal rise) had been attenuated in the patients of the pressor group before erythropoietin treatment and erythropoietin decreased the nocturnal fall of blood pressure further more. Erythropoietin elevated nocturnal blood pressure more than diurnal blood pressure. Therefore, the increase in blood pressure induced by erythropoietin was detected more reliably by ambulatory blood pressure monitoring. There was no relation between the change in hemoglobin concentration and the increase in ambulatory blood pressure induced by erythropoietin. Erythropoietin tended to decrease cardiac output and plasma volume while it increased total peripheral resistance. It also decreased plasma norepinephrine and vasopressin levels but did not affect other humoral factors. Although the pressor effect of erythropoietin treatment for 8 weeks at the dose of 4500 IU/week was not evident on clinic blood pressure measurements, any increase in blood pressure determined by ambulatory blood pressure should be treated carefully to reduce the risk of a cardiovascular complication in patients receiving hemodialysis.

Aldosterone↗
PubMed1995

[A combined consecutive therapy with fosfomycin and sulbactam/cefoperazone for bacterial infections associated with hematological diseases].

A combination antibacterial therapy with fosfomycin (FOM) and sulbactam/cefoperazone (SBT/CPZ) was applied to 78 patients with severe infections associated with hematological diseases. In this protocol, FOM was followed by SBT/CPZ and each drug was administered for 1 hour intravenously and consecutively. Among 72 evaluable patients, 43 patients had acute leukemia, myeloblastic or lymphoblastic, 22 had malignant lymphoma, 3 had multiple myeloma, and 4 had other hematological diseases as underlying diseases. Bacterial infections diagnosed were sepsis in 21 patients, suspected sepsis in 47, and other infections in 4. The overall efficacy rate of this treatment was 72.2%, and those for individual infections were 66.7% for sepsis, 74.5% for suspected sepsis, and 75.0% for other infectious diseases. Among 22 bacteria separated from patients with sepsis, 78.6% (11/14 strains) were eradicated by this treatment. This protocol was also effective in 57.1% (8/14) of patients whose granulocyte count was less than 100/mm3 during the course of treatment as well as in 83.3% (15/18) of patients with granulocyte count over 500/mm3. There was no difference in effectiveness between those patients to whom G-CSF was administered and those to whom it was not (17/24, 70.8% vs 35/48, 72.9%). As an adverse reaction, a transient increase of GOT and/or GPT was observed in 2 patients (2.8%). The consecutive administration treatment of FOM and SBT/CPZ is thus an effective and safe regimen for the treatment of patients with hematological diseases complicated by severe infections.

Adult↗
PubMed1995

Detection of D1S80 (pMCT118) locus polymorphism using semi-nested polymerase chain reaction in skeletal remains.

We evaluated the usefulness of a semi-nested polymerase chain reaction (PCR) method for detecting D1S80 (pMCT118) locus polymorphisms of DNA extracted from old skeletal remains. The semi-nested PCR has been applied to the amplification of D1S80 nucleic acid sequences. For amplification of the locus D1S80, a pair of oligonucleotide primers have been used widely as described by Kasai et al. We have designed another set of primers for semi-nested PCR. This method resulted in D1S80-VNTR detection from low-titered DNA isolated from old skeletal remains. The first and second step PCR achieved amplification from as little as 10 ng and 10 pg of template DNA, respectively. Specificity and sensitivity of the amplification products was markedly improved by semi-nested PCR. In DNA extracted from biological samples, this method took about 5 hours to amplify the target DNA and 3 hours for electrophoretic separation. We demonstrated that this semi-nested PCR method was superior in sensitivity to conventional 1-step standard amplification for VNTR typing of the D1S80 locus.

Base Sequence↗
PubMed1995

Analysis of pedestrian injuries in traffic accidents (2)--Especially on leg injury.

A deep case study on 118 pedestrians struck to fronts of vehicles or vehicle derivatives was carried out. In this paper we investigated a leg injury which occurs the most frequently in a vehicle-pedestrian collision. The data obtained from the case study were compared with those of autopsied cases. Influence of impact speed and point, and of an accident pattern were considered. The leg injury showed higher AIS (Abbreviated Injury Scale) than that of the arm injury caused by direct impact against the front exterior of vehicles. The impact speed and ISS (Injury Severity Score) showed strong correlation, but the former and AIS did not show significant correlation. The higher impact speed and the run-over are likely to cause a bilateral leg fracture.

Abbreviated Injury Scale↗
PubMed1995

Prospective monitoring of minimal residual disease during the course of chemotherapy in patients with acute lymphoblastic leukemia, and detection of contaminating tumor cells in peripheral blood stem cells for autotransplantation.

A prospective study for detecting minimal residual disease (MRD) was conducted on children with acute lymphoblastic leukemia (ALL). Thirty-nine patients (38 B-lineage ALL, one T-ALL) with TCR delta rearrangements could be followed for 21 to 44 months (mean 30.9 months) excluding four patients who died. One hundred and ninety four bone marrow (BM) samples and 13 peripheral blood stem cell (PBSC) grafts were available for detection of MRD. Initially 34 cases were treated prospectively according to the CCLSG risk-stratified protocols for ALL (ALL874 or ALL911), and five cases according to the other protocols. Conventional chemotherapy was replaced by autologous PBSC transplantation (PBSCT) in five patients, by allogenic BM transplantation (BMT) in one patient, or suspended in another patient. Twenty-nine of 32 children in whom conventional chemotherapy could be continued without interruption remain in complete remission (CR). In 24 of the 29 patients MRD became undetectable within 12 months of their diagnosis. In five cases, BM samples obtained during maintenance therapy exhibited residual leukemia cells, and yet none of them relapsed (mean follow-up period 28.6 months). Our results thus indicate that intensive maintenance therapy for patients with PCR-positive results during consolidation therapy may prevent subsequent relapse. Nine events of relapse were diagnosed in eight patients (five BM, two isolated central nervous system (CNS), one combined BM and CNS, one isolated skin relapse). An increase or a re-emergence of MRD was detected in BM samples obtained from patients prior to BM relapse, but one patient remained in CR despite reappearance of leukemic cells following a PCR-negative status. Monitoring of MRD failed to predict isolated CNS or skin relapse. PBSCT allows high-dose cytoreduction therapy for patients with refractory neoplasia. In our study, leukemic cells were identified in eight of 13 PBSC grafts harvested from five patients. Three of four children who received PBSC grafts containing leukemic cells relapsed within 6 months after PBSCT. Monitoring of MRD as part of quality control of PBSC grafts may ultimately contribute to improvements in PBSCT procedures.

Child↗
PubMed1995

[Detection of minimal residual disease by means of FISH and PCR methods and its clinical evaluation].

The monitoring of MRD by FISH and PCR is now clinically evaluated for a prediction of the relapse of leukemia. However, these methods include several technical limitations. In FISH, an appropriate cut off value should be settled for each probe or procedure in estimating chromosomal gain, loss, or translocation and the sensitivity depends on the cut off values but it may reach to 10(-3). In PCR, the sensitivity is higher than that of FISH especially using genomic DNA as a template. However, the detection of chromosomal translocation-specific DNA or RNA constructs is currently applicable to limited cases and the amplification of Ig or TCR gene rearrangement has a major pitfall caused by the clonal evolution. Clinically, MRD can be an indicator for a prediction of the relapse. For example, a greater MRD on entering CR tends to be related with an early relapse, a return to MRD-positive after disappearance of MRD will be a sign of impending relapse, and MRD negativity at the termination of therapy may be correlated with a long-term disease free status. More precise evaluation of MRD is necessary with regard to therapeutic strategy.

Humans↗
PubMed1994

Induction of cytochrome P450 isozymes in rat renal microsomes by cyclosporin A.

To examine the effects of cyclosporin A (CsA) on renal cytochrome P450 forms, CsA was administered to rats, and the renal levels of P450 were determined by immunoblotting. CsA treatment for 17 days increased total renal P450 content by 40% with a concomitant elevation of the omega- and (omega-1)-hydroxylation activities of lauric acid. Arachidonic acid omega-hydroxylation activity was also induced 2-fold by treatment with CsA for 17 days. Among the P450 forms, CYP4A2 was induced significantly, whereas CYP2C23, CYP4A1 and CYP4A8 were unaffected. These changes were accompanied by slight but significant increases in blood urea nitrogen and systolic blood pressure. These data suggest that CsA increased arachidonic acid omega-hydroxylation activity by the induction of CYP4A2. The specific induction of CYP4A2 may be related to CsA-induced nephrotoxicity and elevated blood pressure, because omega-hydroxyarachidonic acid is a potent vasoconstrictor.

Animals↗
PubMed1994

Enhanced synthesis of metallothionein as a possible cause of abnormal copper accumulation in LEC rats.

Long-Evans rats with a cinnamon-like coat color (LEC) is an inbred strain accumulating copper (Cu) in the liver abnormally and showing spontaneous hepatitis and hepatoma. The present study was intended to clarify how Cu accumulates in the LEC rat liver. For this purpose, the distribution profiles of Cu and zinc (Zn) and the inducibility of metallothionein (MT) synthesis were examined in the liver between Cu-loaded Long Evans agouti (LEA, the original strain of LEC) rats and were compared with those in control LEC rats. LEA rats (female, five weeks old) were injected subcutaneously with CuCl2 daily at a dose of 3 mg Cu/kg body weight for 2, 4, 6, and 9 days. The concentration of Cu (124 micrograms/g) accumulated in the LEA rat liver after four injections was comparable to that in control LEC rats. Only 20% of Cu in the liver of LEA rats was recovered in the supernatant fraction in the form of MT, while Cu in the LEC rat liver (113 micrograms/g) was recovered mostly in the supernatant fraction, and was bound to MT. Although the increased concentration of Cu in the LEA rat liver was further elevated after additional injections of Cu, the amount of MT did not increase further. The MT mRNA content in the LEA rat liver remained lower than that of LEC rats even after further injections of Cu. Therefore, the present results suggest that LEC rats can accumulate Cu at a high concentration in the liver because of their extremely high inducibility of MT.

Animals↗