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Y Hiraoka

Publications and source records attributed to Y Hiraoka.

At least 19 recordsLinked to original sources
PubMed1995

Colony-stimulating factors and coxackievirus B3 myocarditis in mice: macrophage colony-stimulating factor suppresses acute myocarditis with increasing interferon-alpha.

The effects of macrophage colony-stimulating factor (M-CSF) and granulocyte colony-stimulating factor (G-CSF) on murine coxsackievirus B3 myocarditis were investigated. A total of 4 x 10(6) U/kg/day M-CSF and 20 micrograms/kg/day G-CSF were injected subcutaneously every day on day 0 to day 14 starting simultaneously with virus inoculation. Serum interferon-alpha was measured periodically. The survival rate of the M-CSF group was higher than that of the untreated control group (p < 0.05). On days 7 and 14 cardiac disease was significantly lower in the M-CSF group than in the untreated control group. Myocardial virus titers on day 7 in the M-CSF group were lower compared with those of the untreated control group. No significant difference was seen in the survival, cardiac disease, or myocardial virus titers between the G-CSF and the control groups. Monocyte counts on days 7 and 14 in the M-CSF group were increased compared with those in the control group. Serum interferon-alpha titers in the M-CSF and G-CSF groups on day 4 and those in the M-CSF group on day 7 were significantly increased in comparison with those of the untreated control group. We conclude that M-CSF but not G-CSF has the potency to limit myocardial virus titers and to reduce cardiac disease in the acute coxsackievirus B3 myocarditis. This ability is associated with an elevated interferon-alpha. Thus macrophages may play a defensive role in this model.

Acute Disease↗
PubMed1994

[Semi-radical transurethral resection of the prostate for small benign prostatic hyperplasia].

The conventional method of transurethral resection of the prostate (TUR-P) is often not beneficial for small benign prostatic hyperplasia (BPH) because of a high frequency of postoperative bladder neck contracture (BNC). Herein, we examined the usefulness of semi-radical transurethral resection of the prostate (semi-radical TUR-P) from the view points of improvement of peak flow rate, the frequency of postoperative BNC and incidental carcinoma of the prostate in 79 cases of small BPH (group A) and 101 cases (group B) of large BPH in which less than 10 g for more than 10 g of the internal glands was resected, respectively. The bladder neck was resected carefully to avoid over resection which may cause BNC in small BPH cases. Satisfactory results were obtained in both groups, that is, the improvement of the peak flow rate from 7.03 +/- 3.79 ml/sec to 13.9 +/- 7.32ml/sec and from 4.96 +/- 2.88 ml/sec to 15.2 +/- 8.30 ml/sec, and the frequency of BNC were 2.53% (2/79) and 1.98% (2/101) in groups A and B, respectively. The frequency of incidental carcinoma of the prostate were 15.2% (12/79) and 17.8% (18/101) in groups A and B. We conclude that semi-radical TUR-P is a favorable maneuver for small BPH because of satisfactory improvement in peak flow rate with low frequency of postoperative BNC and its superiority in screening test for incidental carcinoma of the prostate.

Aged↗
PubMed1992

Effects of polyethylene glycol conjugated superoxide dismutase on coxsackievirus B3 myocarditis in mice.

OBJECTIVE: The aim was to examine the role of oxygen derived free radicals in the development of myocarditis by investigating the effects of polyethylene glycol conjugated superoxide dismutase (PEG-SOD), a potent scavenger of oxygen free radicals, upon coxsackievirus B3 (CB3) myocarditis. METHODS: Two week old male C3H/He mice were inoculated intraperitoneally with 10(3) plaque forming units of CB3. PEG-SOD, 1 x 10(3), 5 x 10(3), 1 x 10(4), and 1 x 10(5) U.kg-1 x d-1, was given subcutaneously daily on days 0 to 14. Treated groups were compared to the infected control. RESULTS: The survival rate of the 1 x 10(5) U.kg-1 x d-1 PEG-SOD group was lower than that of the infected control group (40% v 78%, p < 0.01). The survival rates of the other treated groups did not differ significantly from the infected control. The myocardial calcification score in the 1 x 10(5) U.kg-1 x d-1 PEG-SOD group was higher than in the infected control group on d 7, when myocardial virus titres did not differ significantly among the five groups. The scores for myocardial cellular infiltration and myocardial necrosis in the 1 x 10(3) and the 5 x 10(3) U.kg-1 x d-1 PEG-SOD groups were significantly lower than in the infected control on d 14, when myocardial viruses were not detected in the five groups. However, the myocardial necrosis and myocardial calcification scores in the 1 x 10(5) U.kg-1 x d-1 PEG-SOD group were higher than in the infected control. CONCLUSIONS: The improvement of cardiac pathology in the 1 x 10(3) and the 5 x 10(3) U.kg-1 x d-1 PEG-SOD groups seems to have resulted not from the reduction in myocardial virus titres but from inhibition of generation of oxygen free radicals. The mechanism of the impaired survival and aggravation of cardiac pathology in the 1 x 10(5) U.kg-1 x d-1 PEG-SOD group is unknown. The results suggest that oxygen free radicals may be involved in the pathogenesis and development of CB3 myocarditis and that appropriate dosages of PEG-SOD have therapeutic potential for clinical CB3 myocarditis, although caution must be paid to the treatment window.

Animals↗
PubMed1992

The effects of FK-506, a novel and potent immunosuppressant, upon murine Coxsackievirus B3 myocarditis.

To test the therapeutic efficacy of immunosuppression with FK-506 upon coxsackievirus B3 myocarditis, C3H/He mice were inoculated with coxsackievirus B3, and the effects of FK-506 were compared to those of cyclosporine. FK-506 (2.5 mg/kg/day) or cyclosporine (25 mg/kg/day) was administered s.c. daily on days 0 to 14 (experiment I) and on days 14 to 28 (experiment II). In experiment I, the survival rate of the FK-506 or cyclosporine-treated group was significantly lower compared with that of the untreated, control group. However, the score of myocardial cellular infiltration in both treated groups was lower compared to the control. On day 14, myocardial virus was not detected in the control group, but was present in both treated groups. Serum neutralizing antibody titers on day 14 in FK-506 group were lower than in the control group. In experiment II, survival rate did not differ significantly among the three groups. Serum-neutralizing antibody titers on day 21 in FK-506 group were lower than in the control. Histologically, marked cellular depletion in the thymus and spleen was evident in FK-506 groups; in cyclosporine groups, it was only evident in the thymus. Thus, FK-506 induced immunosuppression in coxsackievirus B3 myocarditis, associated with a high mortality, notwithstanding the reduction of myocardial cellular infiltration in the acute stage when immune mechanisms play a role in the pathogenesis of the disease. With respect to the dosage, the immunosuppressive action of FK-506 in vivo is at least 10-fold stronger compared to that of cyclosporine.

Animals↗
PubMed1992

[Operation of female stress incontinence--comparison between Raz procedure and Gittes procedure].

We performed Raz procedure and Gittes procedure for female stress incontinence since October 1986. Raz procedure was performed on 19 patients between October 1986 and February 1990, and Gittes procedure was performed on 18 patients between June 1990 and May 1991. We followed up 17 patients who underwent Raz procedure and all the patients who underwent Gittes procedure at the time August 1991. Disappearance or marked improvement of incontinence was confirmed in 12 patients by Raz procedure, and 16 patients by Gittes Procedure. No serious complications were recognized. The reason why the result of Raz procedure was not sufficient was due to our immature operative technique and incorrect patient selection in our early experience. From this experience, we believe that both procedures can be very useful and minimal invasive operation for female stress incontinence.

Adult↗
PubMed1992

[Clinical studies on Kock continent urinary reservoir and Indiana continent urinary reservoir].

Recently, the continent urinary reservoir which provides the patient with a better quality of life has become popular. Many types of reservoirs have been reported, but the optimal procedure remains to be established. From July 1987 through November 1988, we performed Kock pouch construction on 11 patients (ages 39 to 76 years). Between July 1989 and March 1991, 9 patients (ages 44 to 66 years) underwent Indiana pouch operation. The first 4 patients underwent ileal patch type, and the subsequent 5 underwent Heineke-Mikulicz type procedure. A one-stage radical cystectomy and continent urinary reservoir construction was performed on 19 patients, and bilateral cutaneous ureterostomy was converted to Kock pouch in one patient. There were no perioperative deaths, but reoperation was required for urinary leakage from the reservoir on one patient in each group. As the late complications in the Kock pouch group, one patient required revisional operation of the continent valve mechanism, 2 patients experienced intermittent prolapse of the nipple valve of the efferent limb, and 2 had malfunction of the afferent nipple valve. In the Indiana pouch group unilateral hydronephrosis was noticed in one patient, and 4 had mild difficulty of catheterization. Although 3 patients in both groups had mild urinary leakage, all patients had good quality of life with capacity of reservoir over 500 ml and with good renal function. We changed the type of operative procedure from Kock pouch to Indiana pouch because of the high complication ratio in the former.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Purification and characterization of the yeast negative regulatory protein GAL80.

Transcription of the GAL genes encoding the enzymes responsible for galactose metabolism in the yeast Saccharomyces cerevisiae is regulated through an interplay of two regulatory proteins, GAL4 and GAL80. GAL4 binds to upstream activating sequences of GAL (UASG) and activates their transcription in yeast growing in the presence of galactose. GAL80 binds to GAL4 and inhibits the activation function of GAL4 in yeast growing without galactose. We have purified GAL80 in its native form as a protein that reacts with an antiserum raised against a synthetic peptide of 18 amino acid residues in the GAL80 sequence. Purification was performed through ammonium sulfate precipitation, streptomycin precipitation, DEAE-cellulose column chromatography, and gel filtration. From 50 g of wet cells, a final sample of 2.3 mg with a purity of more than 80% was obtained. The molecular size of the purified protein in both the native and denatured states was estimated to be approximately 50 kDa, indicating that GAL80 exists as a monomer in yeast cells. The amino-terminal residue of GAL80 was found to be acetylmethionine. The purified protein was shown to bind GAL4. We have also purified mutant GAL80 proteins encoded by two different alleles of gal80 known to be incapable of inhibiting the function of GAL4. These proteins were, in fact, unable to bind GAL4.

Chromatography, Gel↗
PubMed1991

Efficient production of biologically active human prolactin in Escherichia coli.

To obtain an adequate amount of human prolactin (hPRL) for elucidation of the structure-function relationship, we have expressed the hPRL cDNA in Escherichia coli (E. coli) by using a high-expression vector. The vector contained a chimeric gene encoding a fusion of protein A, a peptide sensitive to collagenase digestion and hPRL, which was inserted downstream of the right direction promotor of lambda phage. The resulting protein fusion was purified through three column chromatographies of immunoglobulin G-linked Sepharose 4B, DEAE-5PW, and phenyl-5PW. In a typical experiment, a final sample with a purity of more than 80% was obtained with a recovery of more than 40% judged by enzyme-linked immunosorbent assay (ELISA). The fusion thus obtained was digested with collagenase, and protein reactive to anti-hPRL antibody was purified through phenyl-5PW column chromatography. The hPRL sample was found to be identical to authentic hPRL with respect to the amino acid composition and an N-terminal sequence of 20 residues, except that it contained an additional four amino acids at the N-terminal end. This peptide was presumed to be derived from the collagenase-target sequence. The hPRL thus obtained was found to be as active as the authentic hormone either immunologically judged by ELISA or biologically judged by the growth stimulatory effect on rat Nb2 lymphoma cells.

Amino Acid Sequence↗
PubMed1991

A placenta-specific 5' non-coding exon of human prolactin.

Expression of human prolactin (hPRL) is restricted to the anterior pituitary and the placenta, strictly, the decidualized endometrium of the uterus. We have cloned and sequenced placental hPRL cDNAs and also the 5' part of the hPRL gene, and found that the placental mRNA consisted of six exons including a 5' non-coding exon which was not present in the pituitary mRNA known to consist of five exons. The placenta-specific exon, designated exon 0, was located 5.3 kb upstream of the first exon of the pituitary mRNA. We have also located the transcriptional start site of the hPRL gene in the placenta to be 21 bp upstream from the 5' end of the longest cDNA clone we obtained using mRNA from human placenta of 22 weeks of gestation. These results suggest that the hPRL gene contains a placenta-specific promoter other than the pituitary-specific promoter.

Amino Acid Sequence↗
PubMed1991

Characterization of the auxin-regulated par gene from tobacco mesophyll protoplasts.

The auxin-regulated par gene from tobacco mesophyll protoplasts was characterized in detail to deduce its possible function. An homology search of the par gene in the NBRF databases revealed that the par gene has homology to the stringent starvation protein (ssp) gene of Escherichia coli, which is induced under starved conditions and binds in an equimolar ratio to a holoenzyme of RNA polymerase. Hence, it is supposed that the par gene product could play a similar role to that of ssp. Although sequence homology of the par gene to the Gmhsp 26-A gene from soybean was observed, both genes were shown to respond differently to plant hormones and stresses. Gmhsp 26-A is induced by heat shock, 2,4-dichlorophenoxyacetic acid (2,4-D), cytokinin and abscisic acid (ABA), whereas the par gene was induced only by auxins. Furthermore, cycloheximide treatment prevents 2,4-D-mediated accumulation of Gmhsp 26-A mRNA, but not that of par mRNA. Both par and Gmhsp 26-A respond to CdCl2, but splicing of the par pre-mRNA proceeded in a normal way, whereas splicing off the Gmhsp 26-A pre-mRNA was inhibited. Hence, the par and Gmhsp 26-A genes should have a common ancestor, but have evolved in different directions. Detailed time-course experiments confirmed that the par gene was induced immediately after the addition of auxin and expressed upon the initiation of meristematic activity in tobacco mesophyll protoplasts. As the par gene was induced by the sole treatment of cycloheximide, it was proposed that the par gene belongs to a category of 'superinduction' genes.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1991

Ethacrynic acid-sensitive and ATP-dependent Cl- transport in the rat kidney.

Ouabain- and furosemide-insensitive and ATP-dependent Cl- uptake was demonstrated in rat renal membrane vesicles. Such a Cl- uptake activity was prominent in cortical plasma membrane fractions with high activities of Cl(-)-ATPase and Na+, K(+)-ATPase. The membrane vesicles accumulated Cl- in an osmotically reactive manner with the following sequence of nucleotide specificity: ATP greater than ITP greater than UTP greater than GTP greater than CTP., beta, gamma-Methylene ATP, ADP and AMP had no effect. ATP-dependent Cl- uptake was markedly inhibited by a Cl(-)-ATPase inhibitor, ethacrynic acid (0.3 mM), but not affected by an H(+)-ATPase inhibitor, N,N'-dicyclohexylcarbodiimide (0.1 mM). These findings suggest that an ethacrynic acid-sensitive and ATP-driven

Adenosine Triphosphatases↗
PubMed1991

[A case of signet ring cell carcinoma of the urachus].

A 71-year-old female was seen initially with the complaint of gross hematuria. Cystoscopic examination revealed non-papillary tumor at the dome of the bladder and a transurethral biopsy showed signet ring cell carcinoma. En bloc segmental resection was performed, and the patient has been well without any evidence of progression. We report a case, which we believe to be the 6th in Japan, of signet ring cell carcinoma of the urachus.

Adenocarcinoma, Mucinous↗
PubMed1991

Three-dimensional multiple-wavelength fluorescence microscopy for the structural analysis of biological phenomena.

Cellular events are accomplished by the coordinated interactions of cellular components within the three-dimensional context of a cell. Simultaneous observation of multiple components in three dimensions can be essential for understanding such interactions. Toward this end, we have developed a computerized microscope workstation capable of recording three-dimensional images of multiple cellular components in fixed and living cells. All aspects of microscope control, data collection, image processing and analysis can be performed on the one workstation. In this report, we describe the components and capabilities of this integrated system. In addition, we discuss some general problems of multiple-wavelength, three-dimensional imaging and our application of this technology to the analysis of chromosome organization in Drosophila melanogaster. Three-dimensional imaging of fixed embryos stained by indirect immunofluorescence has revealed the structural organization of chromosomes, microtubules, and the nuclear lamins. Imaging of living embryos injected with fluorescently labelled proteins has confirmed and extended these results by allowing the study of these structures throughout the cell cycle. The combination of the molecular specificity of fluorescence microscopy and the three-dimensional structural information obtained by our workstation has provided novel insights into the dynamic aspects of chromosome behavior during the cell cycle. We believe this system has many important applications in the study of the molecular basis of cellular events.

Animals↗
PubMed1990

Kinetics of disulfide bond reduction in alpha-lactalbumin by dithiothreitol and molecular basis of superreactivity of the Cys6-Cys120 disulfide bond.

Kinetics of disulfide reduction in alpha-lactalbumin by dithiothreitol are investigated by measuring time-dependent changes in absorption at 310 nm and in CD ellipticity at 270 nm (pH 8.5 or 7.0, and 25 degrees C). When the disulfide-intact protein is folded, the kinetics are biphasic. The disulfide bond between the half-cystines-6 and -120 is reduced in the fast phase, and the other three disulfide bonds are reduced in the slow phase. The apparent rate constants of the two phases are both proportional to the concentration of dithiothreitol, indicating that both phases are expressed by bimolecular reactions. However, detailed molecular mechanisms that determine the reaction rates are markedly different between the two phases. The slow phase shows a sigmoidal increase in the reaction rate with increasing concentration of a denaturant, urea, and is also accelerated by destabilization of the native state on removal of the bound Ca2+ ion in the protein. The disulfide bonds are apparently protected against the reducing agent in the native structure. The fast phase reaction rate is, however, decreased with an increase in the concentration of urea, and the disulfide bond shows extraordinary superreactivity in native conditions. It is 140 times more reactive than normal disulfides in the fully accessible state, and three-disulfide alpha-lactalbumin produced by the fast phase assumes nativelike structure under a strongly native condition. As ionic strength does not affect the superreactivity of this disulfide bond, electrostatic contributions to the reactivity must be negligible. Inspection of the disulfide bond geometry based on the refined X-ray coordinates of baboon alpha-lactalbumin [Acharya et al. (1989) J. Mol. Biol. 208, 99-127] and comparison of the geometry with those in five other proteins clearly demonstrate that the superreactivity arises from the geometric strain imposed on this disulfide bond by the native structure folding. Relationships of the disulfide strain energy to the protein stability and the disulfide reactivity are discussed.

Chemical Phenomena↗
PubMed1990

Synthesis of human gamma-glutamyl transpeptidase (GGT) during the fetal development of liver.

We have determined expression of human GGT gene encoding gamma-glutamyl transpeptidase (GGT) during fetal development of liver using the Northern-blot analysis with a cloned human GGT cDNA and immunohistochemistry with a monoclonal antibody. GGT mRNA could be detected as early as the 12th week of gestation. It then increased gradually to a peak of approx. threefold the amount at week 12, at week 40, just before birth. The size of the mRNA in the fetal liver was 2.7 kb and mRNA of the same size was detected both in the human fetal kidney and human hepatocellular carcinoma as well as normal adult liver. Immunohistochemical analyses show that GGT increased as the fetal liver developed in parallel with the increase in mRNA. Histochemically, GGT was shown to be located in the wall of bile canaliculi when synthesis was low in early development, but to be distributed, in addition, all over the cell membrane of the fetal hepatocytes when synthesis was high at the later stage of development.

Blotting, Northern↗
PubMed1990

Signal sequence for generation of mRNA 3' end in the Saccharomyces cerevisiae GAL7 gene.

We have identified a signal sequence (designated core signal) necessary to specify formation of mRNA 3' end of the GAL7 gene in Saccharomyces cerevisiae within a DNA segment 26 bp long. The sequence was located 4-5 nucleotides upstream from the 3' end, i.e. the polyadenylation site, of the GAL7 mRNA. Replacement of a DNA segment encompassing the polyadenylation site with a pBR322 DNA, leaving the core signal intact, resulted in alteration of the mRNA 3' end by several nucleotides, suggesting the existence of an additional signal (designated end signal) at or near the polyadenylation site. The normal end formation was abolished when the core signal was placed in the reverse orientation. A considerable fraction of pre-mRNA synthesized in vitro with SP6 RNA polymerase on the template of a DNA fragment containing these signals was cleaved and polyadenylated presumably at the in vitro 3' end during incubation in a cell-free system of yeast. By contrast pre-mRNA synthesized on the template with the core signal alone was processed but much less efficiently. No such processing was seen when the pre-mRNA either lacked the core signal or contained it in the reverse orientation.

Base Sequence↗