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Biomedical subjects

H Nishio

Publications and source records attributed to H Nishio.

At least 127 records · Page 7Linked to original sources
PubMed1996

Role of cytokines in leukemic type growth of myelodysplastic CD34+ cells.

The clonal growth of progenitor cells from myelodysplastic syndromes (MDS) can be subdivided into four growth patterns: (1) normal, (2) no growth or low plating efficiency, (3) low colony and high cluster number, and (4) normal or high colony number with a large number of clusters. The former two (1 and 2) can be referred to as nonleukemic patterns and latter two (3 and 4) as leukemic. In a search for a role for cytokines in leukemic-type growth of MDS progenitor cells, marrow CD34+ cells were purified up to 94% for 8 normal individuals and 88% for 12 MDS patients, using monoclonal antibodies and immunomagnetic microspheres (MDS CD34+ cells). The purified CD34+ cells were cultured for 14 days with various combinations of cytokines, including recombinant human macrophage colony-stimulating factor (rM-CSF), granulocyte-CSF (rG-CSF), granulocyte-macrophage-CSF (rGM-CSF), interleukin-3 (rIL-3), and stem cell factor (SCF; a ligand for c-kit) in serum-free medium. The clonal growth of MDS CD34+ cells supported by a combination of all of the above cytokines was subdivided into the two patterns of leukemic or nonleukemic, and then the role of individual or combined cytokines in proliferation and differentiation of MDS CD34+ cells was analyzed in each group. Evidence we obtained showed that SCF plays a central role in the leukemic-type growth of MDS CD34+ cells and that G-CSF, GM-CSF; and/or IL-3 synergize with SCF to increase undifferentiated blast cell colonies and clusters over that seen in normal CD34+ cells. SCF is present in either normal or MDS plasma at a level of nanograms per milliliter, and this physiologic concentration of SCF can stimulate progenitor cells. This means that progenitor cells are continuously exposed to stimulation by SCF in vivo and that MDS leukemic cells have a growth advantage over normal blast cells. This depends, at least in part, on cytokines such as G-CSF, GM-CSF, IL-3, and SCF.

Acute Disease↗
PubMed1996

Tandem arrangement of the human serum albumin multigene family in the sub-centromeric region of 4q: evolution and chromosomal direction of transcription.

The albumin gene family is comprised of four genes encoding: serum albumin (ALB), alpha-fetoprotein (AFP), alpha-albumin (ALF), and vitamin D-binding protein (DBP; also known as GC). The genes are regulated developmentally, expressed in the liver, and the proteins are secreted into the bloodstream. The GC gene, and the tandemly linked ALB and AFP genes, have been previously localized to human chromosome 4q11-13. Using techniques of fluorescence in situ hybridization to chromatin fibres, chromosome walking and DNA sequencing of genomic clones, we now report on the chromosomal location of the ALF gene and the organization of the entire gene family. The four genes are tandemly linked in the 4q sub-centromeric region: 5'ALB-5'AFP-5'ALF-5'GC3'-centromere, and hence are transcribed in the same, centromere-bound, direction. The linear arrangement of the four genes along the chromosome is not correlated with their temporal expression in the human ontogeny. It appears that GC is very close (and may be the gene proximal) to the centromere. The linear chromosomal arrangement of the four genes and the structural differences between them are congruent with the following evolutionary divergence of the gene family. Starting with the first duplication of an ancestral progenitor gene, a single evolutionary line led to the contemporary GC, leaving ALB/AFP/ALF on the other line of descent. The second duplication occurred in this ALB lineage, giving rise to ALB and the AFP/ALF progenitor, and the third, most recent one, gave rise to the AFP-ALF pair.

Albumins↗
PubMed1996

A common mutation in methylenetetrahydrofolate reductase gene among the Japanese population.

Hyperhomocysteinemia has been reported as an independent risk factor for atherosclerotic cerebrovascular and coronary heart diseases. 5, 10-Methylenetetrahydrofolate reductase (MTHFR) is one of the enzymes responsible for hyperhomocysteinemia. The C to T transition of the MTHFR gene at nucleotide position 677 results in decreasing the enzymatic activity and increasing the plasma homocysteine level. We studied the distribution of the MTHFR gene mutation among the Japanese population. The subjects were 129 Japanese males (aged 40-59 years). The allele frequency of the mutation was 0.38. The frequencies of the three genotypes were as follows: +/+, 11%; +/-, 54%; -/-, 35% (+ and-indicate the presence and absence of the mutation, respectively). We also studied the frequency of the MTHFR gene mutation in the middle-aged Japanese males with hypertension to investigate the possibility that this mutation is related to essential hypertension. The normotensive and hypertensive subjects were identical in the distribution of the mutated allele and the frequencies of the three genotypes. Furthermore, the prevalence of hypertension in each genotype group was same, although the mean diastolic pressure of the group with homozygous mutation was significantly higher than that of other groups (p < 0.05). Therefore, we concluded that there was no significant relationship between the MTHFR gene mutation and hypertensive subjects studied in this study.

Adult↗
PubMed1996

Accumulation of Tc-99m HMDP in hepatic metastasis from colon carcinoma without detectable calcification.

A 51-year-old man was found to have hepatic metastasis from colon carcinoma. Bone scintigraphy with 99mTc-hydroxymethylene diphosphonate showed a ringlike accumulation corresponding to the hepatic mass, which was without calcification on computed tomography. Treatment with chemotherapeutic agents was started. After 4 months, computed tomography showed that the mass was smaller than before and that the margin was calcified. The extraosseous accumulation of the radionuclide may be evidence supporting earlier speculation on calcification that could not yet be detected by computed tomography.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

Re-examination for pharmacological properties of serotonin-induced tachycardia in isolated guinea-pig atrium.

In the presence of 10(-6) M atropine, 5-HT induced a positive chronotropic and inotropic effect in isolated guinea-pig atrium preparation. Both propranolol, a beta-adrenoceptor blocker, and imipramine, a 5-HT uptake inhibitor, did not affect the response induced by 5-HT, indicating that a tyramine-like mechanism is not involved. The positive chronotropic effect of 5-HT was mimicked by several 5-HT3 receptor agonists. N omega-Methyl-5-HT, reported to have a high affinity for 5-HT1B recognition sites, was found to act as a 5-HT3 receptor agonist with higher efficacy. The other 5-HT receptor agonists tested did not produced any responses. The positive chronotropic effect of 5-HT was inhibited by various 5-HT3 receptor antagonists, such as tropisetron, granisetron, ondansetron, cisapride and zacopride, but it was unaffected by various 5-HT receptor antagonists which are not selective for 5-HT3 receptor. Thus, the positive chronotropic response to 5-HT is a direct effect, and it was suggested to be mediated by 5-HT3 receptor subtype with rather an atypical profile.

Adrenergic Uptake Inhibitors↗
PubMed1996

Effects of thimerosal, an organic sulfhydryl modifying agent, on serotonin transport activity into rabbit blood platelets.

The effects of the sulfhydryl group inhibitor thimerosal on serotonin (5-HT) transport activity into rabbit blood platelets were investigated, along with its effects on the intracellular concentration of Ca2+ ([Ca2+]i). 3H-5-HT transport activity into rabbit blood platelets was inhibited by treatment with 10(-5) M thimerosal for 30 min, which did not cause 5-HT release from platelets. The thimerosal-induced inhibition of 5-HT transport was antagonized by dithiotheritol. It was suggested that the thimerosal acts as a sulfhydryl inhibitor and inhibits 5-HT transport activity independently of the 5-HT release reaction in our experiment using rabbit blood platelets. As aspirin did not affect thimerosal-induced 5-HT transport inhibition, it was suggested that the thromboxane A2-generating system does not operate in the effect of thimerosal on 5-HT transport into blood platelets. Furthermore, thimerosal induced a transient elevation of [Ca2+]i, which was followed by a sustained increase. In the absence of extracellular Ca2+, thimerosal caused only a transient increase in [Ca2+]i. It was suggested that the elevation of [Ca2+]i consisted of two phases, e.g. a transient phase induced by Ca2+ mobilization from the intracellular store sites and a sustained phase which might be explained by Ca2+ influx from the extracellular environment. In conclusion, thimerosal inhibited 5-HT transport into blood platelets at a concentration which did not induce 5-HT release, and intracellular Ca2+ mobilization might mediate the inhibitory effect of thimerosal on 5-HT transport.

Animals↗
PubMed1996

5-HT3 receptor blocking properties of the antiparkinsonian agent, talipexole.

1. Talipexole showed moderate displacement activity of 3H-GR 65630 binding to 5-HT3 receptors in both rat cortical and intestinal membrane fractions with Ki values of 0.35 microM and 0.22 microM, respectively. 2. Bromocriptine failed to displace the binding activity in either experimental system even at a concentration of 10 microM. 3. Both talipexole and tropisetron were found to significantly inhibit 5-HT3 receptor-mediated effects of 5-HT in isolated guinea-pig ileum or atrium; however, the effect of talipexole was weaker than that of tropisetron. 4. Bromocriptine, in contrast, had no antagonistic effects on 5-HT3 receptor-mediated activity in guinea-pig ileum or atrium. 5. It was concluded that talipexole might act as an antagonist on 5-HT3 receptors in both brain and intestinal tissues.

Animals↗
PubMed1996

Human astrocytoma cells (U-87 MG) exhibit a specific substance P binding site with the characteristics of an NK-1 receptor.

To investigate substance P (SP) receptors on an established human astrocytoma cell line (U-87 MG), [3H][Sar9,Met(O2)11]-SP, a selective SP receptor agonist, was used to identify and characterize the cell membrane binding sites for SP. SP receptor mRNA was examined by solution hybridization analysis, and the existence of SP binding protein on the surface of membranes was evaluated by flow cytometry using an anti-SP binding protein antibody. In U-87 MG and U-373 MG RNA preparations, transcripts were identified that corresponded to both mature and partially spliced receptor forms. In U-87 MG cell membrane-enriched preparations, the binding of [3H][Sar9,Met(O2)11]-SP was found to be time and cell number dependent, specific, saturable, and of high affinity. Equilibrium binding analysis revealed a single class of binding sites with an apparent KD of 1.15 +/- 0.15 nM and a Bmax of 108 +/- 9.8 fmol/mg of protein. [3H][Sar9, Met(O2)11]-SP binding was basically not influenced by addition of mono (Na+, Li+) or divalent (Mg2+, Mn2+, Ca2+) cations; only high doses of divalent cations decreased the binding. GTP and guanylyl-5'-imidodiphosphate, but not GDP and GMP, reduced the Bmax without changing the affinity of [3H][Sar9,Met(O2)11]-SP. We also examined the effects of pretreatment with three lectins [concanavalin A (con A), wheat germ agglutinin (WGA), and Lens culinaris agglutinin (LCA)] to determine the nature of carbohydrate chains on the U-87 MG cell. Of three lectins analyzed for effects on agonist binding, WGA and LCA had an inhibitory effect, whereas con A was ineffective. These results suggest that SP receptors on the human astrocytoma cell line U-87 MG have either a biantennary complex-type or a high mannose-type of carbohydrate chain and may be regulated by GTP-binding protein(s).

Astrocytoma↗
PubMed1996

VIP- and PACAP-mediated nonadrenergic, noncholinergic inhibition in longitudinal muscle of rat distal colon: involvement of activation of charybdotoxin- and apamin-sensitive K+ channels.

1. The mediators of nonadrenergic, noncholinergic (NANC) inhibitory responses in longitudinal muscle of rat distal colon were studied. 2. An antagonist of pituitary adenylate cyclase activating peptide (PACAP) receptors, PACAP6-38, concentration-dependently inhibited the rapid relaxation of the longitudinal muscle induced by electrical field stimulation (EFS), resulting in a maximal inhibition of 47% at 3 microM. 3. PACAP6-38 inhibited the relaxation by 75% in the presence of the vasoactive intestinal peptide (VIP) receptor antagonist, VIP10-28 at 3 microM, which inhibited the relaxation by 44%. 4. An antagonist of large conductance Ca(2+)-activated K+ channels, charybdotoxin, concentration-dependently inhibited the rapid relaxation of the longitudinal muscle, resulting in a maximal inhibition of 58% at 100 nM. 5. An antagonist of small conductance Ca(2+)-activated K+ channels, apamin, concentration-dependently inhibited the relaxation (58% at 1 microM). 6. Treatment with both K+ channel antagonists resulted in 84% inhibition of the EFS-induced relaxation, which is comparable to the extent of inhibition induced by PACAP6-38 plus VIP10-28. 7. The inhibitory effect of VIP10-28 and of apamin, but not of charybdotoxin was additive: the same applied to PACAP6-38 and charybdotoxin, but not apamin. 8. Exogenously added VIP (100 nM 1 microM) induced a slow gradual relaxation of the longitudinal muscle. Charybdotoxin, but not apamin significantly inhibited the VIP-induced relaxation VIP10-28, but not PACAP6-38 selectively inhibited the VIP-induced relaxation. 9. Exogenously added PACAP (10-100 nM) also induced slow relaxation. Apamin and to a lesser extent, charybdotoxin, inhibited the PACAP-induced relaxation. PACAP6-38, but not VIP10-28 selectively inhibited the PACAP-induced relaxation. 10. Apamin at 100 nM inhibited inhibitory junction potentials (i.j.ps) induced by a single pulse of EFS Apamin also inhibited a rapid phase, but not a delayed phase of i.j.ps induced by two pulses at 10 Hz. VIP10-28 did not inhibit i.j.ps induced by a single pulse, but significantly inhibited the delayed phase at two pulses. A combination of apamin and VIP10-28 abolished the i.j.ps induced by two pulses. 11. Both VIP and PACAP induced slow hyperpolarization of the cell membrane of the longitudinal muscle. Apamin inhibited the PACAP-, but not VIP-induced hyperpolarization. 12. From these findings it is suggested that VIP and PACAP are involved in NANC inhibitory responses of longitudinal muscle of the rat distal colon via activation of charybdotoxin- and apamin-sensitive K+ channels, respectively.

Animals↗
PubMed1996

Nitric oxide-mediated relaxation without concomitant changes in cyclic GMP content of rat proximal colon.

1. We studied the relation of nitric oxide-mediated relaxation of longitudinal muscle to changes in cyclic GMP content of the tissue in the proximal colon of rats. 2. Dimethylphenylpiperazinium (DMPP) and electrical field stimulation (EFS) induced nitric oxide-mediated relaxation of the segments with a concomitant increase in cyclic GMP content. 3. LY 83583 and methylene blue, soluble guanylyl cyclase inhibitors, significantly inhibited the stimulatory effects of DMPP and EFS on the cyclic GMP content, but did not affect the relaxant responses of the segments to DMPP and EFS. 4. Rp-8 bromo cyclic GMPS, an inhibitor of cyclic GMP-dependent protein kinase had no effect on DMPP- and EFS-induced relaxation. 5. These data strongly suggested that nitric oxide-mediated relaxation of the rat proximal colon is not associated with change in cyclic GMP content of the tissue.

Aminoquinolines↗
PubMed1996

A Japanese boy with myalgia and cramps has a novel in-frame deletion of the dystrophin gene.

We report a Japanese Becker muscular dystrophy (BMD) patient with occasional myalgia and cramps during normal activity that developed at the age of 28 months. His family history was negative for neuromuscular diseases. Muscle biopsy analyses, including dystrophin immunostaining, disclosed no clinically relevant findings. The diagnosis of BMD was initially made at the age of 10 years, when indications of persistent high serum levels of CK prompted us to screen deletions in the dystrophin gene by amplification of 19 deletion-prone exons from the genomic DNA by the polymerase chain reaction (PCR). Among the exons examined, exons 13 and 17 were deleted. To clarify the size of the deletion, the dystrophin transcript was analyzed by reverse transcription PCR. The determined nucleotide sequence of the amplified product encompassing exons 10 to 20 disclosed that the entire segment corresponding to exons 13 to 18 (810 bp) was absent, a deletion that would be expected to cause the production of a dystrophin protein lacking 270 amino acids from the rod domain. This result indicates that occasional myalgia and cramps could be early clinical manifestations of mild BMD, especially in patients who have a deletion in the rod domain, and that deletion screening of the dystrophin gene might be the only reliable method to diagnose such cases.

Base Sequence↗
PubMed1996

Cooperation of ATP and norepinephrine in inducing contraction in guinea pig vas deferens is not associated with change in intracellular Ca2+ level.

Contractile responses and fura-2 fluorescence signals were simultaneously recorded in fura-2 loaded longitudinal muscle strips of guinea pig vas deferens to examine the relationship between cooperation of ATP and norepinephrine (NE) in the contractile response and intracellular Ca2+ level. ATP or NE induced a rapid or delayed contraction, respectively, with concomitant changes in fura-2 signal. Addition of both agonists potentiated the rapid, but not delayed contraction, while there was no potentiation in the fura-2 signal. In another series of experiments, NE (> or = 10 microM) contracted the muscle without further concomitant increase in Ca2+ level, indicating "Ca2+ sensitization" of the contractile apparatus. These findings suggest that cooperation of ATP and NE in inducing a rapid contraction of guinea pig vas deferens is mainly due to the "Ca2+ sensitization" effect of NE.

Adenosine Triphosphate↗
PubMed1996

Inhibitory effect of EGTA on serotonin transport into rabbit blood platelets: possible involvement of the glycoprotein IIb/IIIa complex.

We reported previously that serotonin (5-HT) transport was attenuated by treatment of platelets with EGTA, and that this inhibitory effect of EGTA was restored by CaCl2. In the present study, the inhibitory effect of EGTA was found to be uncompetitive, and no inhibitory effect was observed when EGTA was added at 20 degrees C. Genistein and thyrphostin A47, both protein tyrosine kinase inhibitors, inhibited Ca(2+)-induced restoration of 5-HT transport. In contrast, the protein tyrosine phosphatase inhibitor phenylarsine oxide significantly augmented Ca(2+)-induced restoration of 5-HT transport. These results might support the hypothesis that the glycoprotein (GP) IIb/IIIa complex, a platelet membrane integrin protein, might regulate 5-HT transport into blood platelets. It is conceivable that Ca2+ chelation by EGTA might cause temperature-dependent dissociation of the GP IIb/IIIa complex, which results in the reduction of 5-HT transport. Rearrangement of the GP IIb/IIIa complex by replenishment of the Ca2+ binding sites might restore the EGTA-induced reduction of 5-HT transport.

Animals↗
PubMed1996

[Benign infantile mitochondrial myopathy caused by reversible cytochrome c oxidase deficiency].

A 2-month-old girl had generalized weakness, profound muscular hypotonia, hepatomegaly and severe lactic acidosis. She needed ventilatory support. Muscle specimen taken at 2 months showed ragged-red fibers, abnormal mitochondria, and reduced cytochrome c oxidase (CCO) staining Biochemical analysis showed CCO activity to be reduced to about 16% of the normal mean. She received carnitine and coenzyme Q10 supplementation from the age of 3 months and abnormal blood lactate values declined to near normal values during the first three weeks. Gradually her condition started to improved: she held her head at 9 months, and walked alone at 15 months. The second biopsy specimen at 3 years and 8 months showed almost normal CCO staining and she was free of clinical signs. This case is an example of a rare benign infantile mitochondrial myopathy caused by CCO deficiency. Early diagnosis is crucial to provide intensive treatment until spontaneous clinical improvement appears. We concluded that carnitine and coenzyme Q10 supplementation was a useful treatment for clinical improvement in patients with a benign infantile mitochondrial myopathy caused by CCO deficiency.

Carnitine↗
PubMed1996

A case of Becker muscular dystrophy resulting from the skipping of four contiguous exons (71-74) of the dystrophin gene during mRNA maturation.

The mutations in one-third of both Duchenne and Becker muscular dystrophy patients remain unknown because they do not involve gross rearrangements of the dystrophin gene. Here we report the first example of multiple exon skipping during the splicing of dystrophin mRNA precursor encoded by an apparently normal dystrophin gene. A 9-year-old Japanese boy exhibiting excessive fatigue and high serum creatine kinase activity was examined for dystrophinopathy. An immunohistochemical study of muscle tissue biopsy disclosed faint and discontinuous staining of the N-terminal and rod domains of dystrophin but no staining at all of the C-terminal domain of dystrophin. The dystrophin transcript from muscle tissue was analyzed by the reverse transcriptase polymerase chain reaction. An amplified product encompassing exons 67-79 of dystrophin cDNA was found to be smaller than that of the wild-type product. Sequence analysis of this fragment showed that the 3' end of exon 70 was directly connected to the 5' end of exon 75 and, thus, that exons 71-74 were completely absent. As a result, a truncated dystrophin protein lacking 110 amino acids from the C-terminal domain should result from translation of this truncated mRNA, and the patient was diagnosed as having Becker muscular dystrophy at the molecular level. Genomic DNA was analyzed to identify the cause of the disappearance of these exons. Every exon-encompassing region could be amplified from genomic DNA, indicating that the dystrophin gene is intact. Furthermore, sequencing of these amplified products did not disclose any particular nucleotide change that could be responsible for the multiple exon skipping observed. Considering that exons 71-74 are spliced out alternatively in some tissue-specific isoforms, to suppose that the alternative splicing machinery is present in the muscle tissue of the index case and that it is activated by an undetermined mechanism is reasonable. These results illustrate a novel genetic anomaly that results in dystrophinopathy.

Child↗
PubMed1995

The chimpanzee alpha-fetoprotein-encoding gene shows structural similarity to that of gorilla but distinct differences from that of human.

The chimpanzee (Pan troglodytes) alpha-fetoprotein (AFP)-encoding gene (AFP) spans 18,867 bp from the transcription start point to the polyadenylation site, and the nucleotide (nt) sequence reveals that the gene is composed of 15 exons, which are symmetrically placed within three domains of AFP. In addition, we report 3121 bp of 5'-flanking sequence and 4886 bp of 3'-flanking sequence. The entire 26,874 bp of contiguous DNA reported here was determined from three overlapping lambda phage clones. The deduced polypeptide chain is composed of a 19-amino-acid (aa) putative leader peptide, followed by 590 aa of the mature protein. The sequence of chimpanzee AFP was compared with those of the previously published human AFP [Gibbs et al., Biochemistry 26 (1987) 1332-1343] and gorilla AFP [Ryan et al., Genomics 9 (1991) 60-72]. At the aa level, the human AFP differs from the chimpanzee at 6 aa positions and from the gorilla at 4 aa positions; the chimpanzee and gorilla differ at 8 aa positions. There are four types of repetitive sequence elements (X, Alu, Xba and Kpn) in the introns and flanking regions of chimpanzee AFP, and they are located in orthologous positions in the human and gorilla AFP. However, one specific Alu and one Xba repeat in introns 4 and 7, respectively, found in human AFP, are absent from orthologous positions in chimpanzee and gorilla AFP. These two repeats represent human-specific novelties that arose from recent DNA transpositions in primate phylogeny.

Amino Acid Sequence↗