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H Hotta

Publications and source records attributed to H Hotta.

At least 109 records · Page 6Linked to original sources
PubMed1994

A protease activation mutant, MVCES1, as a safe and potent live vaccine derived from currently prevailing Sendai virus.

Sendai virus fresh isolates were shown to be antigenically different from the prototype Fushimi strain that had long been passaged in embryonated chicken eggs. Phylogenetic analysis of the hemagglutinin-neuraminidase genes also revealed the difference between these two virus groups. Both trypsin-resistant and elastase-sensitive mutations were additionally introduced to an LLC-MK2-cell-adapted and attenuated mutant derived from one of the fresh isolates. This protease activation mutant (MVCES1) showed the same antigenicity as the fresh isolates, and as a result of a single cycle of growth in lungs, it could confer better protection on mice against challenge infection with the currently prevailing Sendai virus than TR-5, which is a trypsin-resistant mutant derived from the Fushimi strain. The eligibility of MVCES1 as an attenuated live vaccine of Sendai virus is discussed.

Amino Acid Sequence↗
PubMed1993

An inhibitor of squalene epoxidase, NB-598, suppresses the secretion of cholesterol and triacylglycerol and simultaneously reduces apolipoprotein B in HepG2 cells.

NB-598, a specific inhibitor of squalene epoxidase, suppressed the secretion of cholesterol and triacylglycerol from HepG2 cells into the medium. L-654,969, an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, inhibited the secretion of cholesterol as potently as NB-598, but did not suppress the secretion of triacylglycerol. Both compounds decreased the intracellular cholesterol content almost equally, and neither of the compounds reduced the intracellular triacylglycerol content. The suppression of lipid secretion by NB-598 was associated with a significant reduction in apolipoprotein (apo) B secretion into the medium. Therefore, the suppression of lipid secretion by NB-598 may be caused by a reduction in the number of triacylglycerol-rich lipoprotein particles. In contrast, the suppression of cholesterol secretion by L-654,969 may be due to a modulation of lipoprotein lipid composition, since this agent did not reduce the secretion of apo B or triacylglycerol. The secretion of apo A-I was unaffected by either NB-598 or L-654,969. Pulse chase studies using [35S]methionine showed that the suppression of apo B secretion by NB-598 depended on an enhancement of intracellular degradation of apo B. These results indicate that the secretion of apo B from HepG2 cells is not regulated by the lipid synthesis alone, and suggest that the mechanism of the hypolipidemic effect of NB-598 involves the suppression of triacylglycerol-rich lipoprotein secretion from the liver as well as an inhibition of cholesterol synthesis in the liver.

Anticholesteremic Agents↗
PubMed1993

Augmentation of protective immune responses against Sendai virus infection by fungal polysaccharide schizophyllan.

When treated with fungal polysaccharide schizophyllan, mice survived otherwise lethal Sendai virus infection. Both intraperitoneal and oral administrations were effective when sonicated schizophyllan with a relative molecular mass (M(r)) of 4.6 x 10(5) was used. Antiviral antibody in the serum could be detected at an earlier time after virus infection and virus spread in the lung was more efficiently inhibited in schizophyllan-treated mice than in untreated controls. Schizophyllan also augmented protective immune responses induced by low doses of a live Sendai virus vaccine that were insufficient to confer complete protection against challenge infection with a virulent strain. On the other hand, schizophyllan did not influence interferon production in mice whether or not infected with Sendai virus. The present results suggest that schizophyllan confers better protection against virus infection through augmentation of antiviral immune responses and can be used as an immune enhancer.

Adjuvants, Immunologic↗
PubMed1993

Somatic afferent regulation of plasma prolactin in anesthetized rats.

The effects of noxious and non-noxious mechanical stimulation of various segmental skin areas (face, forelimb, abdomen, and hindlimb) on the plasma concentrations of prolactin (PRL) were examined in anesthetized rats. The experiments were performed on urethane-anesthetized female Wistar rats, ventilated artificially, on the day of estrus. Blood samples (0.5 ml) were collected from the femoral artery every 20 min. Plasma concentrations of PRL were determined by radioimmunoassay. Noxious mechanical stimulation was delivered by pinching the skin with a surgical clamp, while non-noxious mechanical stimulation was delivered by brushing the skin with a toothbrush. Pinching the hindpaw for 6 min significantly increased plasma PRL concentration during stimulation to about 280% of the prestimulation value (p < 0.05). Pinching the face, the forepaw or the abdomen had no significant effect. Brushing of any skin area for 6 min did not significantly change plasma PRL concentrations. These results indicate that cutaneous, nociceptive sensory information contributes to the reflex regulation of PRL secretion from the anterior pituitary when emotional factors are eliminated by anesthesia, and this effect is highly dependent on the site of stimulation.

Afferent Pathways↗
PubMed1993

The contribution of human c-fos DNA to cultured synovial cells: a transfection study.

To clarify the role of c-fos DNA in the activation of human synovial cells, the pH8 expression vector containing human c-fos DNA under the control of murine leukemia virus long terminal repeat was transfected into cultured synovial cells. After G418 selection, the control transfectant clones transfected with pH8 vector not containing c-fos DNA insertion changed their original fibroblastic shape into dendritic cells. They stopped growing at this stage. However, the c-fos DNA transfectant clones continued to grow actively beyond this stage, and regained the fibroblastic appearance. Furthermore, c-fos DNA transfectants adhered to and grew on hyaluronidase treated cartilage surfaces more extensively than control transfectants after 6 days in culture. These findings suggest that c-fos DNA supports active growth of human synovial cells by facilitating transition of synovial dendritic cells into fibroblastic cells.

Arthritis, Rheumatoid↗
PubMed1992

Genomic structure of the ME491/CD63 antigen gene and functional analysis of the 5'-flanking regulatory sequences.

Genomic structure of the ME491/CD63 antigen gene and promoter activity of the 5'-flanking regulatory sequences were studied. The antigen gene consists of eight exons that span 4 kilobase-pairs. Primer extension analysis with RNA from cultured human cells identified three major transcription initiation sites. The 5'-flanking region of exon 1 has features characteristic to promoters of many house-keeping genes and growth-regulating genes. The region is highly GC rich and contains potential binding sites for transcription factors such as Sp1 and ETF, but not a TATA box. The 5'-flanking sequence exerted strong promoter activity when linked to a reporter gene. Deletion mutant analysis of the 5'-flanking sequence has strongly suggested that a potential binding site for AP-1 plays an important role in positively regulating the gene expression.

Amino Acid Sequence↗
PubMed1992

Evaluation of a protease activation mutant of Sendai virus as a potent live vaccine.

A protease activation mutant of Sendai virus, TR-5, was investigated as a candidate for a live vaccine. Vaccination with TR-5 which had been activated by chymotrypsin beforehand (active TR-5) elicited protective immunity against otherwise lethal challenge infection with wild-type Sendai virus in DBA/2, C3H and ICR strains of mice. Less of the active TR-5 was required to confer protection on mice compared with an ordinary ether-inactivated Sendai virus vaccine (split vaccine). The protective immunity elicited by TR-5 lasted longer and the booster effect was more prominent compared to the split vaccine. No seroconversion was observed with contact mice when housed in a cage with mice vaccinated with the active TR-5. The overall results show that the active TR-5 is an effective and safe live vaccine of Sendai virus in mice.

Administration, Inhalation↗
PubMed1992

Identification of Oklahoma isolate as a strain of Pseudomonas pseudomallei.

Based on the morphological, physiological, biochemical and nutritional characteristics, cellular fatty acid and lipid composition, ubiquinone-8 as the major respiratory quinone, guanine-plus-cytosine content of DNA, DNA-DNA homology value, and sequence alignment of 16S rRNA nucleotides, Oklahoma isolate was reidentified as a strain of Pseudomonas pseudomallei.

Anti-Bacterial Agents↗
PubMed1992

Proposal of Burkholderia gen. nov. and transfer of seven species of the genus Pseudomonas homology group II to the new genus, with the type species Burkholderia cepacia (Palleroni and Holmes 1981) comb. nov.

Based on the 16S rRNA sequences, DNA-DNA homology values, cellular lipid and fatty acid composition, and phenotypic characteristics, a new genus Burkholderia is proposed for the RNA homology group II of genus Pseudomonas. Seven species in this group were transferred to the new genus. Thus seven new combinations, Burkholderia cepacia (Palleroni and Holmes 1981), Burkholderia mallei (Zopf 1885), Burkholderia pseudomallei (Whitmore 1913), Burkholderia caryophylli (Burkholder 1942), Burkholderia gladioli (Severini 1913), Burkholderia pickettii (Ralston et al 1973) and Burkholderia solanacearum (Smith 1896) were proposed.

Amino Acids↗
PubMed1992

Hypothalamic corticotropin-releasing hormone (CRH) secretion into hypophysial portal blood is regulated by cutaneous sensory stimulation in anesthetized rats.

The effects of noxious and non-noxious mechanical stimulation of various segmental skin areas (face, forelimb and forepaw, abdomen, hindlimb and hindpaw) on the secretion of immunoreactive corticotropin-releasing hormone (iCRH) from the hypothalamus into hypophysial portal blood was examined in artificially ventilated rats under halothane anesthesia. Secretion of iCRH was calculated from the iCRH concentration in hypophysial portal plasma and the plasma flow rate. Noxious mechanical stimulation of the skin was delivered by pinching using surgical clamps, while non-noxious mechanical stimulation was provided by brushing with tooth brushes. Pinching of the bilateral forepaws or hindpaws and brushing of the bilateral hindlimbs for 20 min increased hypothalamic iCRH secretion. In contrast, pinching of the face or abdomen and brushing of the face, forelimbs, or abdomen for 20 min did not significantly influence it. These results indicate that cutaneous mechanical sensory stimulation contributes to the reflex regulation of CRH secretion from the hypothalamus into hypophysial portal blood, and also that this effect is highly dependent on the site of stimulation.

Animals↗
PubMed1991

Stimulation of lumbar sympathetic trunk produces vasoconstriction of the vasa nervorum in the sciatic nerve via alpha-adrenergic receptors in rats.

The effects of repetitive electrical stimulation of a lumbar sympathetic trunk (LST) for 30 s at various frequencies and supramaximum intensity on the nerve blood flow in a sciatic nerve were studied by laser Doppler flowmetry in anesthetized Fischer-344 male rats. The response was biphasic; i.e. an initial increase and then a decrease. The maximum mean increase after 2 Hz stimulation was 22 +/- 8%, while the maximum mean decrease after 20-50 Hz stimulation was 79 +/- 3%, of the prestimulus control level. The initial increase, which was greater at lower frequencies and existed even after local sympathetic denervation, was passive, and was caused by the systemic pressor response to LST stimulation. The decrease, which was nearly abolished by an i.v. alpha-adrenergic blocker, phentolamine (10 mg/kg), resulted from vasoconstriction in the vasa nervorum, mainly via activation of alpha-adrenergic receptors.

Animals↗
PubMed1991

Effect of a novel squalene epoxidase inhibitor, NB-598, on the regulation of cholesterol metabolism in Hep G2 cells.

We have reported previously that NB-598 competitively inhibits human squalene epoxidase and strongly inhibits cholesterol synthesis from [14C]acetate in cultured cells. Furthermore, multiple oral administration of NB-598 decreased serum cholesterol levels in dogs (Horie, M., Tsuchiya, Y., Hayashi, M., Iida, Y., Iwasawa, Y., Nagata, Y., Sawasaki, Y., Fukuzumi, H., Kitani, K., and Kamei, T. (1990) J. Biol. Chem. 265, 18075-18078). In the present study, the effects of NB-598 on 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and low-density-lipoprotein (LDL) receptor were examined using a human hepatoma cell line Hep G2. Incubation of Hep G2 cells with NB-598 for 18 h increased HMG-CoA reductase activity in a dose-dependent manner. However, the increase in activity induced by NB-598 was lower than that induced by L-654,969 (a potent HMG-CoA reductase inhibitor), although NB-598 inhibited cholesterol synthesis more potently than L-654,969. On the other hand, HMG-CoA reductase mRNA was increased to the same extent by both inhibitors. These results demonstrate that NB-598 does not inhibit the synthesis of non-sterol derivative(s) of mevalonate, which regulate HMG-CoA reductase activity at the post-transcriptional level. NB-598 increased the binding of 125I-LDL to Hep G2 cells. LDL receptor mRNA was also induced by NB-598. In the presence of LDL or cycloheximide, NB-598 did not increase LDL receptor activity. These results demonstrate that the induction of LDL receptor activity by NB-598 is due to increases in mRNA and protein through the inhibition of cholesterol synthesis at the squalene epoxidase step. From these observations, squalene epoxidase inhibitor is expected to be highly effective in the treatment of hypercholesterolemia and also is very useful as a research tool for studying the regulation of cholesterol metabolism.

Acetates↗
PubMed1991

Prevalence of antibody to influenza C virus among pigs in Hyogo Prefecture, Japan.

The prevalence of influenza C virus among pigs in Hyogo Prefecture, Japan, was investigated by serological techniques. Out of 240 sera tested, 45 (19%) showed haemagglutination inhibition (HI) to influenza C virus. Pig sera with high HI titres also scored high in neutralization tests and ELISAs. When fractionated by sucrose density gradient ultracentrifugation, the HI/ELISA reactivities corresponded to antibodies of the IgM and IgG classes. Radioimmunoprecipitation tests revealed that some, but not all, of the pig sera with high HI activities precipitated HEF glycoprotein of influenza C virus. These results suggested that the HI activities of pig sera in Hyogo Prefecture were due to the presence of antibody to influenza C virus. Sera with IgM class antibody to influenza C virus were found throughout the year. However, the question of whether or not pigs serve as a natural reservoir for human influenza C virus still remains to be solved.

Animals↗
PubMed1991

Protection of mice by a protease inhibitor, aprotinin, against lethal Sendai virus pneumonia.

Proteolytic activation of Sendai virus in the lungs of mice is necessary to cause pneumopathogenicity. Using Sendai virus-infected lung block cultures, protease inhibitors were tested for their antiviral effect by examining inhibition of proteolytic activation. Among the inhibitors tested, a serine protease, aprotinin, was shown to be most effective. In vivo protection experiments demonstrated that aprotinin, when administered intranasally, could confer protection on mice against lethal Sendai virus pneumonia through the same mechanism as observed in the in vitro system. The present study provides an experimental basis for the use of protease inhibitors as antiviral drugs.

Animals↗