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Biomedical subjects

I Yoshida

Publications and source records attributed to I Yoshida.

At least 253 records · Page 14Linked to original sources
PubMed1987

Role of interferon in the augmented resistance of trehalose-6,6'-dimycolate-treated mice to influenza virus infection.

Mice inoculated intravenously with 10 to 100 micrograms trehalose-6,6'-dimycolate in an oil-in-water emulsion (TDM emulsion) acquired high resistance to intranasal infection by influenza virus at 7 to 14 days, but not at 1 day, after treatment. Mice inoculated with an oil-in-water emulsion without TDM (control emulsion) did not resist infection. The activity of the reticuloendothelial system of mice inoculated with TDM emulsion or control emulsion was greatly stimulated 1 day and 14 days after treatment. Interferon production in response to influenza virus was augmented in lung and serum of TDM emulsion-treated mice. The augmented interferon production was greatly diminished in the TDM emulsion-treated mice by treatment with anti-Thy-1.2 monoclonal antibody. Production of haemagglutination-inhibiting antibody in the TDM emulsion-treated or control emulsion-treated mice was higher than that in untreated mice, although no difference was observed between the TDM emulsion-treated and control emulsion-treated mice. On the other hand, TDM emulsion treatment of mice did not influence the appearance of antibody-producing cells, nor the activity of natural killer cells in the mice. The enhanced resistance of mice was diminished by inoculating anti-interferon-alpha/beta serum before influenza virus infection. No detectable interferon activity was observed in lung and blood of mice inoculated with anti-interferon-alpha/beta serum prior to influenza virus infection. These results suggest that the augmented early interferon production in T-lymphocytes of TDM emulsion-treated mice in response to influenza virus may play an important role in the enhanced resistance.

Animals↗
PubMed1987

High-performance liquid chromatographic separation of corticosteroids in plasma of rats. Its application to the determination of the circadian rhythm of 18-hydroxycorticosterone related to aldosterone and corticosterone.

An efficient separation of corticosteroids in plasma of rats was obtained by reversed-phase high-performance liquid chromatography (HPLC). Plasma corticosteroid assays with HPLC separation were used to determine the circadian rhythm of 18-hydroxycorticosterone (18-OHB) and its possible relationship to aldosterone or corticosterone in conscious rats under standard conditions (regular diet; 12-hour light and 12-hour dark cycle). Significant circadian rhythms of plasma corticosterone, 18-OHB and aldosterone were observed with peak values at 20.00 h and nadir values at 08.00 h. The mean ratio of plasma 18-OHB to aldosterone during 24 h was 2.4. The circadian rhythm of 18-OHB was also correlated with that of plasma aldosterone or corticosterone.

18-Hydroxycorticosterone↗
PubMed1987

Inhibition of mitochondrial functions by margosa oil: possible implications in the pathogenesis of Reye's syndrome.

Margosa oil (MO), a fatty acid-rich extract of the seeds of the neem tree and a reported cause of Reye's syndrome, has been used in the induction of an experimental model of Reye's syndrome in rats. It has been reported that MO causes a decrease in in vivo mitochondrial enzyme activity similar to that seen in Reye's syndrome. We have attempted to uncover some of the biochemical mechanisms of MO's toxicity by examining its effect in vitro on isolated rat liver mitochondria. Male rat liver mitochondria were isolated by centrifugation; oxygen uptake, reduced forms of cytochrome b, c + c1, a + a3, and flavoprotein, intramitochondrial concentrations of acetyl coA, acid-soluble coA, acid-insoluble coA, and ATP content were measured after incubation with and without MO. Our results reveal that MO is a mitochondrial uncoupler. State 4 respiration was increased while the respiratory control ratio was decreased. The intramitochondrial content of ATP was also decreased. There were substantial changes in the reduction of the respiratory chain components after incubation of mitochondria with MO. This decelerative effect on mitochondrial electron transport was alleviated by the addition of coenzyme Q and/or carnitine. These effects of MO on mitochondrial respiration may be due to changes in fatty acid metabolism caused by MO as MO caused a shift in the proportion of acid-soluble or acid-insoluble coA esters. Supplementary therapy with L-carnitine and coenzyme Q may be useful in the management of MO-induced Reye's syndrome.

Animals↗
PubMed1987

Effect of atrial natriuretic factor on aldosterone and its precursor steroid production in adrenal zona glomerulosa cells from spontaneously hypertensive rats.

The effect of alpha-human atrial natriuretic factor (alpha-hANP, 10(-6) M- 10(-8) M) on basal, and maximum angiotensin II (AII, 4.8 X 10(-8) M)-, ACTH (4.3 X 10(-9) M)-, and potassium (8mM)-stimulated levels of corticosterone, 18-hydroxycorticosterone (18-OHB) and aldosterone production were studied in adrenal glomerulosa cells from spontaneously hypertensive rats (SHR) at 14 weeks of age as compared to those in the age-matched Wistar-Kyoto rats (WKY) on a normal sodium diet. Plasma corticosterone, 18-OHB and aldosterone levels and the aldosterone response in vitro to the graded doses of AII were similar in SHR and WKY. Basal, and maximum AII-, ACTH-, and potassium-stimulated levels of corticosterone, 18-OHB and aldosterone also were similar in the cells from SHR and WKY. alpha-hANP similarly inhibited basal and stimulated levels of these corticosteroids in the cells from SHR and WKY. These results indicate that the inhibitory effect of alpha-hANP on aldosteronogenesis is unaltered in SHR at 14 weeks of age on a normal sodium diet.

18-Hydroxycorticosterone↗
PubMed1987

Studies in the development of Japanese encephalitis vaccine: expression of virus envelope glycoprotein V3 (E) gene in yeast.

A safe, effective and economical vaccine is required for the prevention of Japanese encephalitis (JE), a disease with high mortality and grave sequelae, which is prevalent in Japan and other countries in east, south-east and southern Asia. As the initial step to produce a second-generation vaccine, recombinant DNA technology was utilized to express the JE virus envelope glycoprotein V3 (E) gene in yeast cells.This report describes the construction of a yeast expression vector in which a cDNA clone covering the V3 gene was connected to the acid-phosphatase promoter of a yeast vector plasmid. Successful expression of the V3 gene was detected by ELISA and Western blotting using monoclonal antibodies against JE V3. Immunization of mice with the V3 antigen expressed in yeast produced limited but definite levels of anti-JE antibodies which could neutralize JE virus. The results are an encouraging step in the development of a practical second-generation JE vaccine.

DNA, Recombinant↗
PubMed1987

[A rare case of adenocarcinoma of the bladder following ileocystoplasty].

This is a report of a case of well-differentiated adenocarcinoma found 14 years after ileocystoplasty. Total cystectomy and right ureterocutaneostomy were performed, and the origin of this tumor was proved to be the ileal part of ileocystoplasty. This is a rare case of adenocarcinoma in the ileal part of ileocystoplasty, because a review of the literature revealed only three other such cases.

Adenocarcinoma↗
PubMed1986

Dihydrolipoyl dehydrogenase deficiency: a therapeutic trial with branched-chain amino acid restriction.

A patient with a deficiency of dihydrolipoyl dehydrogenase and neurological disease is described. The patient was placed on a branched-chain amino acid-restricted regimen. After the introduction of the regimen, there were some biochemical improvements and he achieved some developmental milestones, in contrast to previously reported patients whose neurological disease was progressive. Restriction of the branched-chain amino acids is worth trying among therapeutic measures for this disease, although restriction of the amino acids alone may not totally prevent progression of neurological disease.

Amino Acids↗
PubMed1986

Acute encephalopathy with hyperammonemia and dicarboxylic aciduria during calcium hopantenate therapy: a patient report.

We report a 3-year-old Japanese girl who developed acute encephalopathy while receiving calcium hopantenate (Calcium D-(+)-4-(2, 4-dihydroxy-3,3-dimethylbutyramido) butyrate hemihydrate). She had hyperammonemia, elevated CPK, lactic acidemia and pyruvic acidemia, however, she did not show elevated SGOT or SGPT. Calcium hopantenate has been used in Japan for the treatment of mental retardation with behavior abnormalities. Recently there have been three reports on the occurrence of Reye-like syndrome in patients receiving this drug. Clinical signs and laboratory data of these patients are similar to those of Reye syndrome. Calcium hopantenate causes pantothenic acid deficiency in the young rat, which may reduce the content of coenzyme A. If this drug decreases coenzyme A biosynthesis, it may reduce beta-oxidation of fatty acids and levels of dicarboxylic acids would increase because of increasing omega-oxidation. We suspect that there is a possible relationship between the occurrence of acute encephalopathy and calcium hopantenate therapy.

Acute Disease↗
PubMed1986

Metabolism of branched-chain amino acids in fibroblasts from patients with maple syrup urine disease and other abnormalities of branched-chain ketoacid dehydrogenase activity.

The metabolism of branched-chain amino acids was studied in cultured fibroblasts from patients with branched-chain ketoacid dehydrogenase deficiency using 1-14C- and UL-14C-leucine and valine. The formation of 14CO2 from 1-14C-valine or 1-14C-leucine was 1-3% of normal. In fibroblasts of patients with associated lactic acidemia the values were 4-29% of control. Analysis of organic acid products revealed that in both patients and controls the amount of labeled alpha-ketoisovalerate recovered after incubation with 1-14C-valine was one-third of the amount of alpha-ketoisocaproate recovered after incubation with 1-14C-leucine. Very little alpha-hydroxyisocaproate was produced, while the amount of alpha-hydroxyisovalerate was about 10% of the alpha-ketoisovalerate. Unexpectedly beta-hydroxyisobutyrate was found to be the major metabolic product of UL-14C-valine in normal fibroblasts. Large accumulations of beta-hydroxyisovalerate were found in normal fibroblasts using UL-14C-leucine. There were little or no conversions to these compounds in fibroblasts of patients with branched-chain ketoacid dehydrogenase deficiency. There were substantial conversions in the patients in whom dehydrogenase deficiency was associated with lactic acidemia.

3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)↗
PubMed1986

Enhancement of interferon-gamma production in glycyrrhizin-treated human peripheral lymphocytes in response to concanavalin A and to surface antigen of hepatitis B virus.

The effects of glycyrrhizin, a component of licorice (Glycyrrhiza glabra) roots, on the production of interferon-gamma in human peripheral lymphocyte-macrophage cultures by concanavalin A (Con A) was examined. Interferon-gamma production in normal lymphocyte-macrophage cultures treated with 10 to 100 micrograms/ml of glycyrrhizin at 37 degrees C for 12 hr or longer, and then treated with 10 micrograms/ml of Con A, was enhanced four to eight times compared to control cell cultures. Lymphocyte-macrophage cultures treated with 10 to 100 micrograms/ml of glycyrrhizin alone did not produce interferon. No significant difference in the adsorption of [3H]Con A to glycyrrhizin-treated and control lymphocyte-macrophage cultures was found, but RNA and protein synthesis of the treated lymphocytes was increased compared to control cells; DNA synthesis, however, was reduced. Collaboration between enriched T-lymphocytes and macrophages, both treated with glycyrrhizin, was needed for the enhancement of interferon-gamma production. A smaller increase in interferon production was also observed in the glycyrrhizin-treated peripheral lymphocyte-macrophage cultures derived from an asymptomatic carrier of hepatitis B virus, in response to Con A and surface antigen of hepatitis B virus.

Cells, Cultured↗
PubMed1986

Oligonucleotide fingerprint analysis on Japanese encephalitis virus strains after passage histories.

Genetic variation in Japanese encephalitis (JE) virus strains after various passage histories was examined by oligonucleotide fingerprints of the 42S genome RNA. The results indicated that genome changes occurred during passages of new virus isolates through cell lines or mouse brains, especially at earlier passage level in order to adapt quickly to different hosts. However, the changes were not sufficient to explain strain differences observed among fingerprints of various isolates.

Animals↗
PubMed1986

[A case of bilateral reticulum cell sarcoma of the testis].

A case of reticulum cell sarcoma of bilateral testis is described. The patient was a 58-year-old man who complained of painless swelling of the right scrotal contents. He was treated by bilateral high orchiectomy. The right testicular tumor was histologically diagnosed as reticulum cell sarcoma, and the left testicular tumor was also diagnosed as RCS. Chemotherapy (vincristin, Endoxan, 6-MP and prednisolone) was performed, and the patient has been doing well without any clinical evidence of recurrence. The literature is reviewed briefly.

Combined Modality Therapy↗
PubMed1986

[A case of bilateral testicular tumor of germ cell origin].

A 28-year-old man visited our clinic with a complaint of painless swelling of left scrotal contents. An initial right semicastration for embryonal carcinoma and seminoma had been performed 10 years earlier. Left semicastration was performed, and its histopathological finding was pure seminoma. A total of 96 cases of bilateral testicular tumors of germ cell origin reported in Japan are summarized and discussed concerning incidence, age, histology, interval, prognosis and mechanism of the tumorigenesis.

Adult↗
PubMed1985

Adsorption of poly rI:rC on cell membrane participating and nonparticipating in interferon induction.

PR-RK cells, which were derived from RK-13 cells by repeated treatment with a copolymer of polyriboinosinic acid and polyribocytidylic acid (poly rI:rC), were resistant to the cytotoxic effect of poly rI:rC, and could not produce interferon when exposed to poly rI:rC alone. These characteristics of PR-RK cells have not reversed for more than 40 passages of the cells in medium without poly rI:rC. Poly rI:rC was adsorbed on PR-RK cells at a rate of 60 to 70% of its adsorption to RK-13 cells. On the other hand, PR-RK cells could produce a low level of interferon when they were induced by a poly rI:rC-DEAE dextran complex, by poly rI:rC and metabolic inhibitors (superinduction), by poly rI:rC and pretreatment with interferon (priming), and by Newcastle disease virus. Interferon production in RK-13 cells in response to poly rI:rC or poly rI:rC-DEAE dextran complex was inhibited by pretreatment of the cells with anti-RK-13 cell serum and anti-RK-13 cell serum absorbed with PR-RK cells. These results suggest that PR-RK cells are deficient in the receptor for poly rI:rC, and that poly rI:rC can adsorb onto the cell membrane nonspecifically, acting as a weak inducer when transcriptional control in cells is affected by superinduction or priming. Only about 30% of the poly rI:rC adsorbed on RK-13 cells may be specific binding, participating in normal interferon induction.

Adsorption↗