Biomedical subjects

N Ishida

Publications and source records attributed to N Ishida.

At least 19 recordsLinked to original sources

PubMed1992

Primary structure of rat renal dipeptidase and expression of its mRNA in rat tissues and COS-1 cells.

Three cDNA clones of rat renal dipeptidase (rrDP) were isolated from rat renal and pulmonary cDNA libraries using a DNA fragment of human renal DP cDNA clone, MDP4, as a probe. The complete amino acid sequence deduced from the cDNA contains 410 amino acid residues, beginning with a signal peptide of 16 amino acid residues. RNA blot hybridization analysis showed that 1.6 and 2.2 kb mRNAs were expressed in lung and kidney, however, only 1.6 kb mRNA was detected in small intestine. COS-1 cells transfected with the cDNA expressed enzymatically active rrDP.

Amino Acid Sequence↗

PubMed1992

An analogue of Joro spider toxin selectively suppresses hippocampal epileptic discharges induced by quisqualate.

The anticonvulsant effect of 1-naphthylacetyl spermine, an analogue of Joro spider toxin (JSTX), was studied against seizures induced by quisqualate (QUIS), a non-NMDA agonist, as assessed electrophysiologically and behaviorally in freely moving rats. Electrodes were implanted into right dorsal hippocampus and an injection cannula for drugs into right ventricle. The pretreatment with JSTX analogue significantly inhibited both of QUIS-induced hippocampal discharges (80-11%) and generalized tonic clonic seizures (100-33%) in a dose-dependent manner, whereas JSTX had no effect on seizures induced by quinolinate, a NMDA agonist. The paper provides the first direct evidence that the JSTX analogue exerts a potent and selective suppression of hippocampal epileptic discharges mediated by non-N-methyl-D-aspartate (non-NMDA) receptors.

Animals↗

PubMed1992

Interleukin-6 down regulates the expression of transcripts encoding cytochrome P450 IA1, IA2 and IIIA3 in human hepatoma cells.

Effects of human interleukin-6 (hIL-6), the major acute phase inducer, on the expression of transcripts encoding cytochrome P450s were examined in human hepatoma-derived cells. Using reverse-transcription polymerase chain reaction, it was demonstrated that three hepatoma cell lines, HepG2, HepG2f and Hep3B, express P450 mRNAs encoding IA1, IA2 and IIIA3, the major P450 isozymes involved in carcinogen metabolism, and that they also show induction responses to treatment with their specific inducers. When hepatoma cells were treated with hIL-6, the levels of IA1, IA2 and IIIA3 mRNAs were markedly suppressed. These findings suggest that significant down regulation of cytochrome P450s may occur during the acute phase reaction, which may result in alterations in drug biotransformation.

Base Sequence↗

PubMed1992

Secretion of endothelin-1 in human endothelial cell line but not in B cell line by transfection of preproendothelin-1 cDNA.

Stable transformants with preproendothelin-1 (preproET-1) cDNA were established for the study of the regulation of endothelin-1 (ET-1) biosynthesis in human cells. ET-1, a potent vasoconstrictor peptide, is produced by endothelial cells and is secreted into the blood at a low level. Human preproET-1 cDNA was introduced into two immortal human cell lines, t-HUE2, an endothelial cell line, and Raji, a B cell line, with Ecogpt selection. Several stable transformants of t-HUE2 expressed extraordinarily high levels of preproET-1 specific mRNA and secreted ET-1 into serum-free culture medium, while the transformants of Raji cells expressed high levels of ET-1 mRNA, but secreted a negligible amount of ET-1. Immunocytochemical studies of intracellular ET-1 content revealed that there were some defects in the translation or processing of preproET-1 in the B cell line transformants. In addition, the ratio of ET-1 to ET-1 precursor (big ET-1) was much higher in the t-HUE2 transformants than in normal endothelial cells, suggesting that t-HUE2 transformants (for example t-HUE2-1) possess high levels of endothelin converting enzyme (ECE). The establishment of stable transformants producing high levels of ET-1 in serum-free medium will be useful for the study of cell-type-specific translation and processing to mature ET-1, and of the regulatory factors of ECE.

B-Lymphocytes↗

PubMed1992

Relationship of urinary pseudouridine and 1-methyladenosine to activity of leukemia and lymphoma.

Urinary levels of pseudouridine and 1-methyladenosine in patients with leukemia and lymphoma were measured by the inhibition ELISA using monoclonal antibodies to determine the correlation of nucleosides excretion with disease activity. Significantly elevated levels of these nucleosides were detected in patients with all types of disease tested. Seventy-seven percent (46/60) and 62% (37/62) of patients had elevated levels of pseudouridine and 1-methyladenosine above normal mean + 2S.D., respectively, and combination assay of these nucleosides gave higher positive rate (87%; 52/60) than either single assay. The changes of urinary pseudouridine and 1-methyladenosine reflected the disease status of patients in remission or in relapse and the effect of chemotherapy. These results suggest that urinary pseudouridine and 1-methyladenosine might be clinically useful as complementary markers to the monitoring of the disease status of patients with leukemia and lymphoma by hematological examination.

Adenosine↗

PubMed1992

Generation of hydroxyl radical from linoleic acid hydroperoxide in the presence of epinephrine and iron.

When linoleic acid hydroperoxide was reacted with ferrous iron, the electron spin resonance signals characteristic of the spin adduct of 5,5-dimethyl-1-pyrroline-N-oxide and the hydroxyl radical were detected. Although the signals were not detected with the hydroperoxide and ferric iron, they were actually found if epinephrine was added, indicating that the hydroxyl radical could be generated from the hydroperoxide upon reduction of the latter with ferrous iron formed by epinephrine. The possible generation of the hydroxyl radical from lipid peroxides in vivo was discussed from the viewpoint of pathogenesis of lipid peroxide-related diseases.

Cyclic N-Oxides↗

PubMed1992

The molecular defect of ferrochelatase in a patient with erythropoietic protoporphyria.

The molecular basis of an inherited defect of ferrochelatase in a patient with erythropoietic protoporphyria (EPP) was investigated. Ferrochelatase is the terminal enzyme in the heme biosynthetic pathway and catalyzes the insertion of ferrous iron into protoporphyrin IX to form heme. In Epstein-Barr virus-transformed lymphoblastoid cells from a proband with EPP, enzyme activity, an immunochemically quantifiable protein, and mRNA content of ferrochelatase were about one-half the normal level. In contrast, the rate of transcription of ferrochelatase mRNA in the proband's cells was normal, suggesting that decreased ferrochelatase mRNA is due to an unstable transcript. cDNA clones encoding ferrochelatase in the proband, isolated by amplification using the polymerase chain reaction, were found to be classified either into those encoding the normal protein or into those encoding an abnormal protein that lacked exon 2 of the ferrochelatase gene, indicating that the proband is heterozygous for the ferrochelatase defect. Genomic DNA analysis revealed that the abnormal allele had a point mutation, C----T, near the acceptor site of intron 1. This point mutation appears to be responsible for the post-transcriptional splicing abnormality resulting in an aberrant transcript of ferrochelatase in this patient.

Amino Acid Sequence↗

PubMed1992

Molecular cloning of cDNAs for rat proteasomes: deduced primary structures of four other subunits.

Proteasomes (multi-protease complexes) are composed of approximately 15 non-identical subunits of similar sizes (molecular weight = 21-32 kDa), but different charges (isoelectric point = 4-9). Previously, we deduced the primary structures of 6 subunits of rat proteasomes by recombinant DNA techniques. In this paper we report the nucleotide sequences of 4 other subunits, rIOTA, rZETA, rDELTA, and rRING12, determined from cDNA clones isolated by screening a rat H4TG hepatoma cell cDNA library with the cDNAs of their human counterparts as probes. The polypeptides deduced from their nucleotide sequences consisted of 246, 241, 202, and 219 amino acid residues with calculated molecular weights of 27,399, 26,391, 21,649, and 23,324, and calculated isoelectric points of 6.37, 4.65, 4.84, and 4.70, respectively. These results and previous findings indicate that the primary structures of the subunits of rat proteasomes show considerably high inter-subunit homology, but can be classified into apparently distinct sub-groups, suggesting that rat proteasome genes form a multi-gene family with the same evolutionary origin, but have diverged during evolution to acquire possibly subunit-specific functions.

Amino Acid Sequence↗

PubMed1992

Impaired NK response of cancer patients to IFN-alpha but not to IL-2: correlation with serum immunosuppressive acidic protein (IAP) and role of suppressor macrophage.

In vitro NK responses of cancer patients (N = 21) to rIFN-alpha A and rIL-2 were examined. The serum concentration of IAP (immunosuppressive acidic protein) was determined in parallel. Five out of seven patients whose serum IAP contents were within the normal range (270 micrograms/ml to 470 micrograms/ml), had their NK activities significantly augmented by rIFN-alpha A and rIL-2. On the other hand, NK cells from ten out of fifteen patients whose serum IAP concentrations were 650 micrograms/ml or more, were not activated by rIFN-alpha A. NK cells of these fifteen patients yet were capable of responding to rIL-2. NK cells from cancer patients, however, became responsive to rIFN-alpha A by either removal of adherent cells or treatment with indomethacin. Therefore, macrophages in PBMC of cancer patients with high serum IAP levels seem to selectively suppress NK response to rIFN-alpha A by an indomethacin-sensitive mechanisms. It was further shown that PGE2 was not the mediator of this suppression.

Adult↗

PubMed1992

Cloning and expression of the defective genes from a patient with delta-aminolevulinate dehydratase porphyria.

Cloning and expression of the defective genes for delta-aminolevulinate dehydratase (ALAD) from a patient with inherited ALAD deficiency porphyria (ADP) were carried out. Cloning of cDNAs for the defective ALAD were performed from EBV-transformed lymphoblastoid cells of the proband, and nucleotide sequences were determined. Two separate point mutations resulting in a single amino acid change in each ALAD allele were identified. One, C718----T, termed 'G1', occurred in the allele within the substrate-binding site, producing an Arg240----Trp substitution; the other, G820----A, termed 'G2', occurred downstream of this site in the other allele, resulting in an Ala274----Thr substitution. Using the reverse transcription-polymerase chain reaction, the mother, the brother, and the sister were shown to have the G1 defect. Expression of the G1 cDNA in Chinese hamster ovary cells produced ALAD protein with little activity; the G2 cDNA produced the enzyme with approximately 50% normal activity. Pulse-labeling studies demonstrated that the G1 enzyme had a normal half life, while the G2 enzyme had a markedly decreased half life. These data thus define the separate point mutations in each ALAD allele, as well as the altered properties of the two enzymic proteins encoded by the mutant genes in a patient with ADP.

Alleles↗

PubMed1992

Diagnostic use of anti-modified nucleoside monoclonal antibody.

By use of monoclonal antibodies (MoAbs) termed APU-6 and AMA-2, we determined the usefulness of urinary modified nucleosides, pseudouridine and 1-methyladenosine, as markers for malignancy. In patients with leukemia and other forms of cancer, these nucleosides elevated significantly and reflected the disease status of patients. The immunohistochemical analysis showed that cancer cells were specifically stained with the MoAbs. Chemical identification of the cellular components reactive with the MoAbs revealed that APU-6-associated antigens were mainly rRNA and AMA-2-associated antigens were mainly tRNA. These results suggest that APU-6 and AMA-2 would be useful tools for clinical and biological studies of cancer.

Adenosine↗

PubMed1992

Preventive effect of a synthetic immunomodulator, 2-carboxyethylgermanium sesquioxide, on the generation of suppressor macrophages in mice immunized with allogeneic lymphocytes.

The effect of 2-carboxyethylgermanium sesquioxide (Ge-132) on the generation of splenic suppressor macrophages (S-M phi) in C3H/He mice (H-2k) immunized with allogeneic spleen cells from C57Bl/6 mice (H-2b) was investigated. We have previously demonstrated that S-M phi expressing I-J antigen, which appeared during alloimmunization, inhibited cytotoxic T lymphocyte (CTL) generation in the MLR and the elimination of these S-M phi before subjection to the MLR resulted in more effective generation of CTL. The CTL activity, which was determined in vivo by the Winn's test, was markedly enhanced when immunized mice received a 100 mg/kg dose of Ge-132. The compound was found to be the most efficacious when injected simultaneously with the immunization. The activity of allospecific CTL co-cultured with M phi fractions obtained from immunized mice in a 4-h 51Cr-release assay was shown to be 31% lysis of the target cells as compared with 90% lysis of the target cells in effector cells co-cultured with normal M phi fractions. In contrast, effector cells co-cultured with M phi fractions from Ge-132-treated immunized mice lysed 95% of the target cells. Analysis of the level of I-J antigen expression on macrophages (M phi) obtained from mice 7 days after immunization revealed a > 2.5-fold increase, whereas I-A antigen expression remained constant when compared with splenic M phi from naive mice. In contrast, the opposite effect on I-J and I-A antigen expression was observed in splenic M phi from alloimmunized mice treated with Ge-132. These results suggest that Ge-132 could regulate CTL generation in alloimmunized mice by preventing the generation of I-J+ S-M phi.

Adjuvants, Immunologic↗

PubMed1992

[Clinical experience of local thermotherapy in the treatment of benign prostatic hyperplasia].

Thirty-five patients with benign prostatic hyperplasia (age range: 45-88 years; average: 67.5 years) underwent local thermotherapy with prostathermer. Clinical therapeutic effect was evaluated in 30 of the 35 patients: 2 patients interrupting from therapy and 3 receiving pretherapeutic indwelling catheters were not included. A total of 6 treatments (2 per week) were performed, each lasting for 60 minutes. As for subjective improvement, improvement of nocturia was noted in 70.0% of all patients and sense of residual urine in 70.7%. Post-therapeutic nocturnal and daytime decreases in urination frequency were statistically significant (p less than 0.01). Objective improvement in residual urine volume occurred in 19 of the 30 cases, and elevation in uroflowmetric maximal flow rate following therapy was statistically significant (p less than 0.05). Among complications ascribable to catheter insertion were urethral bleeding (3 cases), epididymitis (1 case) and pyuria (1 case). Therapeutic result based primarily on subjective symptoms and partly on objective findings was fairly good in 17 cases (about 57%), and slightly good in 25 cases (about 83%). In conclusion, this therapy seems to be useful in the treatment of benign prostatic hyperplasia.

Aged↗

PubMed1992

Cloning and expression of the defective genes in delta-aminolevulinate dehydratase porphyria: compound heterozygosity in this hereditary liver disease.

Cloning and expression of the defective genes for ALAD from a patient with inherited ADP were carried out. Two separate point mutations, termed G1 and G2, resulting in a single amino acid change in each ALAD allele, were identified. The G1 mutation (C718-->T) occurred in the allele within the substrate-binding site, producing an Arg240-->Trp substitution; the G2 mutation (G820-->A) occurred downstream of this site in the other allele, resulting in an Ala274-->Thr substitution. Using RT-PCR, the mother, the brother, and the sister were shown to have the G1 defect. Expression of the G1 cDNA in CHO cells produced ALAD protein with little activity; the G2 cDNA produced the enzyme with approximately 50% normal activity. Pulse-labeling studies demonstrated that the G1 enzyme had a normal half-life, while the G2 enzyme had a markedly decreased half-life. These data thus define two separate point mutations, one in each ALAD allele, as well as the altered properties of the two enzymic proteins encoded by the mutant genes in this patient.

Adolescent↗

PubMed1992

Comparison of EEG between nasopharyngeal and scalp leads with the aid of an automatic EEG analysis system.

We analyzed the EEG quantitatively with an automatic EEG analysis system, and introduced this system for investigation the relationship between the scalp EEG and nasopharyngeal EEG. The EEG was recorded from healthy volunteers by photic stimulation. We found that components of slow waves like delta and theta were more rich but alpha component was less in the nasopharyngeal EEG than in the scalp EEG. In the analysis of the rate of the appearance of each EEG wave using photic stimulus, a decrease of alpha 1 and an increase of theta 1 are observed in the scalp EEG while there are no specific changes of them in the nasopharyngeal and scalp EEGs. The nasopharyngeal EEG obtained from the vicinity of the base of the brain was thought to originate from the vicinity of the brain stem.

Adult↗

PubMed1991

The protective effects of SA3443, a novel cyclic disulfide, on chronic liver injuries in rats.

The effects of (4R)-hexahydro-7,7-dimethyl-6-oxo-1,2,5-dithiazocine-4- carboxylic acid (SA3443), a novel cyclic disulfide compound, on the development of chronic liver injury were studied in rats, using two types of models, carbon tetrachloride (CCl4)-induced chronic liver injury and heterologous serum (swine serum)-induced liver fibrosis. SA3443 (30-100 mg/kg, p.o.) significantly suppressed increases in serum transaminase and alkaline phosphatase activity induced by CCl4-treatment for 10 weeks. This compound also inhibited increases in hepatic lipids and hydroxyproline content in CCl4-treated rats. In the histopathological studies, treatment with SA3443 resulted in a decrease in the degree of hepatic necrosis, fibrosis and steatosis. On the other hand, 8-weeks treatment with swine serum revealed hepatic fibrosis without appearance of necrosis or fatty accumulation. In this model, SA3443 (30 mg/kg, p.o.) reduced the hepatic hydroxyproline level, and diminished the formation of connective tissue in the liver. These findings indicate that SA3443 protects the liver against chronic liver injuries induced by CCl4 and heterogeneous serum.

Animals↗

PubMed1991

A study on house fire victims: age, carboxyhemoglobin, hydrogen cyanide and hemolysis.

Correlation among age, concentrations of carboxyhemoglobin and hydrogen cyanide, oxygen density and hemolysis were studied in 120 house fire victims. Victims aged over 60 years comprised approximately 50% of the pooled subjects. Blood samples were mainly collected from the left ventricle, but sometimes from both the right and left ventricles. The concentration of carboxyhemoglobin ranged from 1-95%, of which 71 persons (59.7%) died with carboxyhemoglobin concentrations below 60%. Carboxyhemoglobin concentrations below 10% were found in 9 persons (7.5%). Most of these cases involved the elderly persons. In this paper, we report on the death of elderly victims as a result of low carboxyhemoglobin concentrations. A significant correlation of blood carboxyhemoglobin concentrations existed between the right and left ventricles. The concentration of carboxyhemoglobin in the left ventricle was significantly higher than that in the right. Two out of 31 victims whose hydrogen cyanide concentrations were determined, succumbed to hydrogen cyanide poisoning, having a high concentration of hydrogen cyanide and a low concentration of carboxyhemoglobin. On analysis, oxygen density was found to be low in 13 persons. A negative correlation was shown between carboxyhemoglobin concentration and hemolysis. Inasmuch as hemolysis may indicate the extent of heat dissociation, hemolysis should provide an index of carbon monoxide dissociation from carboxyhemoglobin. In the present study of victims, possible causes of death i.e., carbon monoxide gas poisoning, hydrogen cyanide poisoning, oxygen deprivation, burning, shock due to burns and others were estimated. The survival time for elderly victims was considered to be short.

Adolescent↗

PubMed1991

Establishment of a human cell line highly expressing endothelin in serum-free medium.

Human preproendothelin-1 (prepro-ET-1) was transfected into an immortal human endothelial cell line that had been cultivated in a serum-free medium. Several transformants selected with Ecogpt selection were probed to have prepro-ET insert, express prepro-ET-1 mRNA, and secrete immunoreactive ET (ir-ET). One of the transformants, t-HUE2-1, secreted 30 times the amount of ET-1 and the ratio of mature ET-1 to big ET-1 was 11-fold higher compared with normal human endothelial cells. Thus, this transformant might be of use to study regulation of the posttranscriptional process of prepro-ET-1 in human cells.

Cell Line↗