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Biomedical subjects

H Mizoguchi

Publications and source records attributed to H Mizoguchi.

At least 91 records · Page 5Linked to original sources
PubMed2000

[Long-term follow up of chronic myelogenous leukemia patients treated with natural interferon alpha--multi-institutional cooperative study].

The effects on survival in patients with chronic myelogenous leukemia (CML) treated with natural interferon alpha (Sumiferon) were analyzed. The subjects were 131 patients with CML who underwent treatment with Sumiferon between August 1991 and December 1992. Sumiferon was administered more than 8 weeks, and patients were followed for 5 years. In the end, 101 patients were analyzed after 30 patients were dropped from the study because they had received bone marrow transplantation. Survivals from the start of Sumiferon administration were 63.4% at 3 years, 52.5% at 4 years, and 42.6% at 5 years, respectively. Survivals were compared between the 74 patients who received Sumiferon administration with 1 year of diagnosis, and the 27 patients who received Sumiferon administration after more than 1 year from diagnosis. The 50% survivals were 2,089 days and 868 days, respectively (p = 0.0011). It was concluded that early administration of interferon alpha results in a prolonged survival of CML patients.

Adult↗
PubMed1999

Interferon-alpha repressed telomerase along with G1-accumulation of Daudi cells.

The implications of telomerase on senescence and human carcinogenesis are widely accepted, but the changes of telomerase activity along with cell cycle modulation by anticancer treatment still remain obscure. In this paper, we issued whether the telomerase activity fluctuated along with cell cycle of cultured cancer cells using the antiproliferative effect of interferon-alpha (IFN-alpha). Daudi Burkitt lymphoma cells, treated with IFN-alpha, showed proliferation inhibition and cell cycle arrest at G1. The telomerase activity at 72 h was repressed to about 20% of control cells. Furthermore, after 72 h IFN-alpha treatment, the cells in G1 phase showed the marked decrease of telomerase activity, while cells in S and G2/M still possessed it. Among expressions of telomerase-related genes, only the catalytic subunit of telomerase (hTERT) decreased from 48 h, while the template RNA component (hTERC) and telomerase-associated protein 1 (TEP-1) were not affected. The downregulation of c-Myc preceded the change of hTERT. Moreover, the analysis of cells treated with IFN-alpha for 24 h revealed that cells in G1-to-S transition mainly expressed high hTERT, while S and G2/M cells had higher level of telomerase activity than that of G1 cells. These results indicate that (i) the expression of hTERT precedes the telomerase activity which is higher in S and G2/M phases than G1 phase, (ii) IFN-alpha repressed the telomerase activity in a cell cycle-dependent manner with the downregulation of hTERT.

Antineoplastic Agents↗
PubMed1999

Clonality of acquired primary pure red cell aplasia.

Acquired primary pure red cell aplasia (PRCA) has frequently been shown to be associated with T cells that inhibit marrow erythropoiesis. A 41-year-old female presented with anemia in December 1985. Bone marrow examination revealed 1.8% erythroid cells. A diagnosis of PRCA was made. She received prednisolone, and her hemoglobin level recovered to 12 g/dl. In February 1995, her hemoglobin level decreased to 5.8 g/dl, and acquired primary PRCA recurred. Surface markers of peripheral blood mononuclear cells demonstrated CD4/8 ratio inversion. The T-cell receptor (TCR)-beta chain gene showed germ line configuration by Southern blot analysis of the mononuclear cells in peripheral blood. However, stepdown polymerase chain reaction analysis revealed that the TCR-beta gene of peripheral blood mononuclear cells was rearranged. With highly sensitive polymerase chain reaction analysis, clonality of T cells was confirmed. We propose that some acquired primary PRCA patients have a T-cell clonal disorder, similar to some PRCA patients with large granular lymphocytes leukemia or thymoma.

Adult↗
PubMed1999

Region-dependent G-protein activation by mu-, delta 1- and delta 2-opioid receptor agonists in the brain: comparison between the midbrain and forebrain.

The ability of selective mu- ([D-Ala2, NHPhe4, Gly-ol]enkephalin: DAMGO), delta1- ([D-Pen2, Pen5]enkephalin: DPDPE) and delta2- ([D-Ala2]deltorphin II: DELT II) opioid receptor agonists to activate G-proteins in the midbrain and forebrain of mice and rats was examined by monitoring the binding of guanosine-5'-O-(3-[35S]thio)triphosphate ([35S]GTPgammaS). The levels of [35S]GTPgammaS binding stimulated by DAMGO in the mouse and rat midbrain were significantly greater than those by DPDPE or DELT II. However, relatively lower levels of stimulation of [35S]GTPgammaS binding by all of the agonists than would have been predicted from the receptor densities were observed in either the limbic forebrain or striatum of mice and rats. The effects of DAMGO, DPDPE and DELT II in all three regions were completely reversed by selective mu-, delta1- and delta2-antagonists, respectively. The results indicate that the levels of mu-, delta1- and delta2-opioid receptor agonist-induced G-protein activation in the midbrain are in good agreement with the previously determined distribution densities of each receptor type. Furthermore, the discrepancies observed in the forebrain might reflect differential catalytic efficiencies of receptor-G-protein coupling.

Analgesics, Opioid↗
PubMed1999

Hair dye use and occupational exposure to organic solvents as risk factors for myelodysplastic syndrome.

To investigate the relationships of personal hair dye use and environmental factors to myelodysplastic syndromes (MDS), we conducted a case-control study in Japan. A total of 111 MDS cases and 830 controls randomly selected from the residents in the same prefecture of cases using telephone directories responded to a health questionnaire. The odds ratio (OR) for ever having used hair dye was 1.99 (95% confidence interval (CI) 1.17-3.38) and there were statistically significant trends in risk with increasing duration and number of hair dye use. Occupational exposure to organic solvents was marginally associated with the risk of MDS (OR = 1.99; 95% CI 0.97-4.10).

Adult↗
PubMed1999

The mu-opioid receptor gene-dose dependent reductions in G-protein activation in the pons/medulla and antinociception induced by endomorphins in mu-opioid receptor knockout mice.

There appear to be different relationships between mu-opioid receptor densities and the acute and neuroadaptive mu-opioid agonist-induced responses of the multiple opioid neuronal systems, including important pons/medulla circuits. The recent success in creating mu-opioid receptor knockout mice allows studies of mu-opioid agonist-induced pharmacological and physiological effects in animals that express no, one or two copies of the mu-opioid receptor gene. We now report that the binding of mu-opioid receptor ligand, [3H][D-Ala2,NHPhe4,Gly-ol]enkephalin to membrane preparations of the pons/medulla was reduced by half in heterozygous mu-opioid receptor knockout mice and eliminated in homozygous mu-opioid receptor knockout mice. The endogenous mu-opioid agonist peptides endomorphin-1 and -2 activate G-proteins in the pons/medulla from wild-type mice in a concentration-dependent fashion, as assessed using [35S]guanosine-5'-o-(3-thio)triphosphate binding. This stimulation was reduced to half of the wild-type levels in heterozygous mice and eliminated in homozygous knockout mice. The intracerebroventricular injection of either endomorphin-1 or endomorphin-2 produced marked antinociception in the hot-plate and tail-flick tests in wild-type mice. These antinociceptive actions were significantly reduced in heterozygous mu-opioid receptor knockout mice, and virtually abolished in homozygous knockout mice. The mu-opioid receptors are the principal molecular targets for endomorphin-induced G-protein activation in the pons/medulla and the antinociception caused by the intracerebroventricular administration of mu-opioid agonists. These data support the notion that there are limited physiological mu-opioid receptor reserves for inducing G-protein activation in the pons/medulla and for the nociceptive modulation induced by the central administration of endomorphin-1 and -2.

Analgesics, Opioid↗
PubMed1999

Roles of endogenous prostaglandins and nitric oxide in gastroduodenal ulcerogenic responses induced in rats by hypothermic stress.

We examined the roles of endogenous prostaglandins (PGs) and nitric oxide (NO) in the gastroduodenal ulcerogenic responses to hypothermic stress (28 approximately 30 degrees C) in anesthetized rats. Lowering body temperature provoked damage in the gastroduodenal mucosa, with an increase of gastric acid secretion and motility. These responses were completely abolished by bilateral vagotomy or atropine, while 16,16-dimethyl PGE2 decreased the mucosal ulcerogenic response with no effect on acid secretion. The non-selective COX inhibitors, indomethacin or aspirin, worsened these lesions with enhancement of gastric motility and no effect on acid secretion, while the selective COX-2 inhibitor NS-398 did not affect any of these responses. On the other hand, the non-selective NOS inhibitor L-NAME but not aminoguanidine (a relatively selective inhibitor of iNOS), significantly potentiated the acid secretory and mucosal ulcerogenic responses in the stomach but reduced the duodenal damage in response to hypothermia, the effects being antagonized by co-administration of L-arginine. Hypothermia itself decreased duodenal HCO3- secretion under both basal and mucosal acidification-stimulated conditions. Both indomethacin and aspirin further decreased the HCO3- response to the mucosal acidification, while L-NAME significantly increased the HCO3- secretion even under hypothermic conditions, similar to 16,16-dimethyl PGE2. These results suggest that 1) hypothermic stress caused an increase of acid secretion and motility as well as a decrease of duodenal HCO3-secretion, resulting in damage in both the stomach and duodenum, 2) the COX-1 but not COX-2 inhibition worsened these lesions by enhancing gastric motility and further decreasing duodenal HCO3- response, 3) the cNOS but not iNOS inhibition worsened gastric lesions by increasing acid secretion but decreased duodenal damage by increasing HCO3- secretion. Thus, it is assumed that the gastroduodenal ulcerogenic and functional responses to hypothermic stress are modified by cNOS/NO as well as COX-1/PGs.

Animals↗
PubMed1999

Cytostatic concentrations of anticancer agents do not affect telomerase activity of leukaemic cells in vitro.

Telomerase, the enzyme that maintains the ends of linear eukaryotic chromosomes, is more active in the majority of malignant tumours than in normal somatic cells. Telomerase plays a key role in the maintenance of chromosomal stability in tumours, but it still remains unknown whether anticancer agents can inhibit telomerase activity. In this study, we evaluated the effect of various anticancer agents (etoposide, cisplatin, irinotecan, mitomycin C and daunorubicin) on the telomerase activity of three human haematopoietic cancer cell lines (Daudi, K562 and U937). A decrease of telomerase activity was not observed in cells treated with IC50 doses of the drugs, except for irinotecan-treated Daudi cells and daunorubicin- and irinotecan-treated U937 cells. Propidium iodide staining disclosed that the cells with decreased telomerase activity were severely damaged. U937 cells exposed to 5 microM (IC90) etoposide showed three different stages of cell viability during treatment. Apoptotic cells with an intact plasma membrane still maintained high telomerase activity, while cells with plasma membrane damage lost telomerase activity. The mRNA of the telomerase catalytic subunit (hTERT) showed a decrease in expression along with the decline of telomerase activity. These results indicate that the concentrations of drugs resulting in cytostatic effects on cells do not affect telomerase activity.

Antineoplastic Agents↗
PubMed1999

Characterization of a PDR1 mutant allele from a clotrimazole-resistant sake yeast mutant with improved fermentative activity.

Clotrimazole-resistant mutants from various sake yeasts show improved fermentative activity in sake mash while retaining their parental advantages for sake making. These mutants also exhibit pleiotropic drug resistance (PDR) phenotypes. To investigate the relationship between the improvement of fermentative activity and PDR phenotypes, a PDR1 mutant allele (pdr1-h176) encoding a transcription factor was cloned from a clotrimazole-resistant mutant, HL176 (MATa/MATalpha), using PCR amplification. The nucleotide sequences of pdr1-h176 and its wild allele were determined. The mutant allele contained a missense point mutation (L309S) that can confer a PDR phenotype on yeast. This amino acid substitution is located in the conserved motif II in the inhibitory domain of Pdr1p, and is very close to the cluster of three mutation points (P298A, K302Q, and M308I) described by Carvajal et al. (Mol. Gen. Genet., 256, 406-415, 1997) in laboratory strains. A PDR1 wild allele of HL163, the parent strain of HL176, was replaced by pdr1-h176 using gene recombination at the homologous site. The resultant transformants (PDR1/pdr1-h176) showed the same PDR phenotype as HL176, and they fermented sake mash efficiently even in the final fermentation stage, while HL163 did not. The amino acid substitution (L309S) in pdr1-h176 was considered to be sufficient to improve the fermentative activity of sake yeast, in addition to conferring the PDR phenotype.

Journal Article↗
PubMed1999

Absence of G-protein activation by mu-opioid receptor agonists in the spinal cord of mu-opioid receptor knockout mice.

1. The ability of mu-opioid receptor agonists to activate G-proteins in the spinal cord of mu-opioid receptor knockout mice was examined by monitoring the binding to membranes of the non-hydrolyzable analogue of GTP, guanosine-5'-O-(3-[35S]thio)triphosphate ([35S]GTPgammaS). 2. In the receptor binding study, Scatchard analysis of [3H][D-Ala2,NHPhe4,Gly-ol]enkephalin ([3H]DAMGO; mu-opioid receptor ligand) binding revealed that the heterozygous mu-knockout mice displayed approximately 40% reduction in the number of mu-receptors as compared to the wild-type mice. The homozygous mu-knockout mice showed no detectable mu-binding sites. 3. The newly isolated mu-opioid peptides endomorphin-1 and -2, the synthetic selective mu-opioid receptor agonist DAMGO and the prototype of mu-opioid receptor agonist morphine each produced concentration-dependent increases in [35S]GTPgammaS binding in wild-type mice. This stimulation was reduced by 55-70% of the wild-type level in heterozygous, and virtually eliminated in homozygous knockout mice. 4. No differences in the [35S]GTPgammaS binding stimulated by specific delta1- ([D-Pen2,5]enkephalin), delta2-([D-Ala2]deltorphin II) or kappa1-(U50,488H) opioid receptor agonists were noted in mice of any of the three genotypes. 5. The data clearly indicate that mu-opioid receptor gene products play a key role in G-protein activation by endomorphins, DAMGO and morphine in the mouse spinal cord. They support the idea that mu-opioid receptor densities could be rate-limiting steps in the G-protein activation by mu-opioid receptor agonists in the spinal cord. These thus indicate a limited physiological mu-receptor reserve. Furthermore, little change in delta1-, delta2- or kappa1-opioid receptor-G-protein complex appears to accompany mu-opioid receptor gene deletions in this region.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1999

Identification of the G-protein-coupled ORL1 receptor in the mouse spinal cord by [35S]-GTPgammaS binding and immunohistochemistry.

1 Although the ORL1 receptor is clearly located within the spinal cord, the functional signalling mechanism of the ORL1 receptor in the spinal cord has not been clearly documented. The present study was then to investigate the guanine nucleotide binding protein (G-protein) activation mediated through by the ORL1 receptor in the mouse spinal cord, measuring the modulation of guanosine-5'-o-(3-[35S]-thio) triphosphate ([35S]-GTPgammaS) binding by the putative endogenous ligand nociceptin, also referred as orphanin FQ. We also studied the anatomical distribution of nociceptin-like immunoreactivity and nociceptin-stimulated [35S]-GTPgammaS autoradiography in the spinal cord. 2 Immunohistochemical staining of mouse spinal cord sections revealed a dense plexus of nociceptin-like immunoreactive fibres in the superficial layers of the dorsal horn throughout the entire length of the spinal cord. In addition, networks of fibres were seen projecting from the lateral border of the dorsal horn to the lateral grey matter and around the central canal. 3 In vitro [35S]-GTPgammaS autoradiography showed high levels of nociceptin-stimulated [35S]-GTPgammaS binding in the superficial layers of the mouse dorsal horn and around the central canal, corresponding to the areas where nociceptin-like immunoreactive fibres were concentrated. 4 In [35S]-GTPgammaS membrane assay, nociceptin increased [35S]-GTPgammaS binding of mouse spinal cord membranes in a concentration-dependent and saturable manner, affording maximal stimulation of 64.1+/-2.4%. This effect was markedly inhibited by the specific ORL1 receptor antagonist [Phe1Psi (CH2-NH) Gly2] nociceptin (1 - 13) NH2. None of the mu-, delta-, and kappa-opioid and other G-protein-coupled receptor antagonists had a significant effect on basal or nociceptin-stimulated [35S]-GTPgammaS binding. 5 These findings suggest that nociceptin-containing fibres terminate in the superficial layers of the dorsal horn and the central canal and that nociceptin released in these areas may selectively stimulate the ORL1 receptor to activate G-protein. Furthermore, the unique pattern of G-protein activation in the present study provide additional evidence that nociceptin is distinct from the mu-, delta- or kappa-opioid system.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1999

Frequent chromosome arm 13q deletion in aggressive non-Hodgkin's lymphoma.

To clarify the role of allelic loss on chromosome arm 13q in lymphomagenesis, we performed fluorescence in situ hybridization (FISH) analysis of a total of 43 primary lymphomas, including both indolent and aggressive non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD), using the specific probes at RB1 and D13S319 loci on the centromeric portion of chromosome arm 13q. Monosomy at either or both RB1 and D13S319 loci was detected in 15 of 43 (35%) lymphomas (14 of 43 cases at RB1 locus and seven of 43 cases at D13S319 locus); the 13q deletion was frequently detected in the aggressive NHLs (40%; 12 of 30 cases) compared with that in indolent NHL (17%; one of six cases) and a subset of HD (29%; two of seven cases). There are only six cases of 43 which have total monosomy 13q14, all aggressive NHL, 14% of total or 20% of this subgroup. In addition, we analyzed the loss of heterozygosity in 15 of the 43 primary lymphoma samples for several polymorphic microsatellite loci (D13S168, RB1 and D13S272) on the chromosome arm 13q, and confirmed the 13q deletion in four of five cases that were positive on FISH analysis. The subchromosomal region frequently altered in lymphoma on 13q14 is the region around RB1 locus and centromeric to D13S319 locus, which is an overlapped region frequently deleted in chronic lymphocytic leukemia. Together, our data indicate that the 13q alterations are present in a variety of types of lymphoma and occur in a significant proportion of aggressive NHLs, suggesting the possible presence of common candidate gene(s) on the 13q14 region, whose alteration may play an important role in the formation or development of a wide variety of mature lymphoid malignancies.

Adult↗
PubMed1999

CD59-deficient blood cells and PIG-A gene abnormalities in Japanese patients with aplastic anaemia.

Patients with aplastic anaemia (AA) frequently develop paroxysmal nocturnal haemoglobinuria (PNH) as a late complication. We investigated the frequency of the development of PNH features including a glycosyl phosphatidylinositol (GPI) anchoring defect in 73 Japanese patients with AA. A deficient expression of CD59 was found on erythrocytes and/or granulocytes in 21/73 (28.8%) of the patients. A Ham/sugar water test was positive in 13/21 patients. We also examined mutations of the PIG-A gene in 11 patients with CD59 deficiency. A heteroduplex analysis detected PIG-A gene abnormality in 10/11 patients tested. Nucleotide sequencing was performed in six patients and identified eight mutations including three mutations in one patient. The mutations of the PIG-A gene were all different and included two single-base insertions, one single-base deletion, two two-base deletions, and one each of eight-base insertion and nine- and ten-base deletions. All mutations but one caused frameshifts. Our findings indicate that a high proportion of Japanese patients with severe AA have a GPI-anchoring defect and that the PIG-A gene is mutated in the AA patients who had a GPI deficiency. We found no significant difference in the pattern of the PIG-A gene mutation between the AA patients with a GPI deficiency and those with de novo PNH.

Adolescent↗
PubMed1999

High inducibility of heat shock protein 72 (hsp72) in peripheral blood mononuclear cells of aplastic anaemia patients: a reliable marker of immune-mediated aplastic anaemia responsive to cyclosporine therapy.

To better characterize immunologic aberrations in aplastic anaemia (AA), we examined peripheral blood mononuclear cells (PBMC) of 67 patients with AA and other patients with various haematological diseases for the expression of heat shock protein 72 (hsp72), which is inducible in lymphocytes by various stressors including antigenic stimulation. When freshly obtained PBMC were examined using flow cytometry, the proportion of cells expressing hsp72 in cytoplasm was significantly higher in allogeneic marrow transplant recipients (22 +/- 15%, mean +/-standard deviation (SD)) and AA patients (17 +/- 21%) than in normal individuals (6 +/- 3%). When PBMC were tested after heat treatment, only the proportion of hsp72+ cells of AA patients (37 +/- 30%) was significantly higher than that of the normal control (17 +/- 11%). Dual fluorescence analysis of the PBMC revealed that the majority of hsp72+ cells was CD3+. For 28 untreated AA patients, the proportion of hsp72+ cells in those who later responded to cyclosporine (CyA) (62 +/- 24%) was higher than that in non-responders (19 +/- 13%). Immunoblotting analysis revealed predominant expression of hsp72 in T cells. These findings indicate that high inducibility of hsp72 in PBMC by heat treatment is an immunologic aberration characteristic of CyA-responsive AA and that this simple test may be useful for identifying a subset of AA patients responsive to immunosuppressive therapy.

Adolescent↗
PubMed1999

Selective effect of cyclosporine monotherapy for pure red cell aplasia not associated with granular lymphocyte-proliferative disorders.

Morphological characteristics of lymphocytes and the response to cyclosporine treatment have revealed some unique patients with pure red cell aplasia. Lymphocytes from these patients consisted mainly of non-granulated lymphocytes. All of the patients were successfully managed by cyclosporine monotherapy irrespective of prior treatment. A reduction in lymphocyte mass was not a prerequisite for the remission of pure red cell aplasia, and responses occurred within 1 month from the start of therapy. Clonal T-cell proliferation was detected in four patients, which raised the possibility of idiopathic pure red cell aplasia being associated with a clonal proliferation of T cells. An examination of the lymphocytes in patients with pure red cell aplasia could potentially be used to plan better therapeutic modalities and assess prognosis.

Adult↗