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Biomedical subjects

S Hirose

Publications and source records attributed to S Hirose.

At least 811 records · Page 45Linked to original sources
PubMed1982

Properties of renin-binding protein.

Hog renal renin-binding protein could bind homologous and non-homologous renin but could not bind human renal renin. Renin-binding protein was only detected in the kidney and pituitary in which renin is found in relatively high concentration. The renal binding protein had no interaction with renal acid proteases nor with extrarenal renins obtained from pituitary and submaxillary glands, indicating that the binding is specific for renal renin. Subcellular localization of the binding protein was studied using rat kidney by differential and density gradient centrifugation. Most renin-binding protein was recovered in the cytosol fraction and was not associated with sedimentable subcellular organelles. A renin-secreting tumor (Juxtaglomerular cell tumor) in human kidney produced not only renin but also renin-binding protein in a very large quantity.

Animals↗
PubMed1982

Protective effect of immediate inoculation of a live varicella vaccine in household contacts in relation to the viral dose and interval between exposure and vaccination.

The protective effect on 45 household contacts of immediate inoculation of a live varicella vaccine was examined in relation to the viral dose and days after exposure to varicella. The viral doses used were 300 PFU to 15,000 PFU, and the intervals between exposure and vaccination were 0 to 5 days. All 30 contacts given viral doses of 800 to 15,000 PFU within 3 days after exposure were protected from clinical varicella. With lower viral doses of 300 to 600 PFU within 3 days after exposure, 6 to 10 contacts developed rashes 13 to 25 days after vaccination, but all showed mild symptoms. When vaccine was given 5 days after exposure, even with a dose of 1,500 to 4,000 PFU, typical varicella symptoms appeared 6 to 9 days after vaccination. These results suggest that vaccination of household contacts with viral doses of over 500-800 PFU within 3 days after exposure is effective in preventing manifestation of clinical varicella and that clinical symptoms may be modified to a mild form by vaccination with even a lower viral dose when given within 3 days after exposure.

Chickenpox↗
PubMed1982

[Antitumor effects of polyamine synthesis inhibitors based on major premise of treatment for human malignant tumor].

The polyamine synthesis inhibitors--alpha-difluoromethylornithine (DFMO) and methylglyoxal bis (guanylhydrazone) (MGBG)--were put to antitumor tests based on the premise of treatment for human gastrointestinal cancer. The both drugs were administered intraperitoneally to BALB/c nude mice xenoplanted human gastric cancer for 10 consecutive days. Both marked antitumor effects and side effects were observed in mice treated at the dosage of DFMO 500 mg/kg/day and/or MGBG 50 mg/kg/day and/or MGBG 30 mg/kg/day brought about significant antitumor effects as well as less side effects. Microscopic observation revealed antitumor actions of these drugs as cytostatic rather than cytocidal. Tumor regrowth after the termination of this combined treatment, however, was noticed. Judging from these data, the both drugs may be effective against human gastrointestinal cancer with minor side effects.

Animals↗
PubMed1982

Routine angiography following partial hepatectomy in patients with malignant lesions of the liver.

Postoperatively, celiac and superior mesenteric angiography was performed upon 17 consecutive patients with malignant lesions of the liver who had undergone partial hepatectomy. Residual or recurrent tumors were detected in six patients. The causes of residual tumors were classified into four patterns; multiple dissemination probably by surgical manipulation, residual tumor at the site of the resectioned stump, erroneous diagnosis preoperatively due to the uptake of contrast material by the major tumor and metachronous occurrence of tumors. Rational treatments for these tumors were proposed. In addition, vascular patterns of the regenerating liver were evaluated in the remaining 11 patients. Stretching and elongation of not only the hepatic artery but also the portal vein in the hepatic remnant were constant findings. The differentiation of residual tumors from regenerating nodules was also discussed.

Adult↗
PubMed1981

Differential stimulation by polyamines of phage RNA-directed synthesis of proteins.

The effect of polyamines on Q beta and MS2 phage RNA-directed synthesis of three kinds of protein in an Escherichia coli cell-free system has been studied. With both phage RNAs, the degree of stimulation of protein synthesis by spermidine was in the order RNA replicase greater than A protein, while the synthesis of coat protein was not stimulated significantly by spermidine. The synthesis of RNA replicase was stimulated by 1 mM spermidine approx. 8-fold. From the results of Q beta RNA direct alanyl-tRNA and seryl-tRNA binding to ribosomes and initiation dipeptide synthesis, it is suggested that the preferential stimulation of the synthesis of RNA replicase by spermidine is due at least partially to the stimulation of the initiation of RNA replicase synthesis.

Bacteriophages↗
PubMed1981

Purification and properties of fMet-tRNAf deacylase from Escherichia coli.

A formylmethionyl-tRNAf deacylase has been purified about 330-fold from a crude initiation factor preparation (1 M NH4Cl ribosomal wash) from Escherichia coli Q13. The enzyme was nearly homogeneous and had an apparent molecular weight of 24 000. Rat liver methionyl-tRNAf and E. coli methionyl-tRNAm were not hydrolyzed significantly by the enzyme under standard conditions. Q beta RNA- and AUG(A)n-directed polypeptide synthesis was inhibited by the enzyme. The inhibition was at the level of initiation of polypeptide synthesis. The enzymatic activity was inhibited by various factors necessary for polypeptide synthesis. The activity was inhibited more by NH4Cl and spermidine than by Mg2+, GTP and ATP. The complex of formylmethionyl-tRNAf, initiation factor 2 and GTP was resistant to enzymatic hydrolysis, and the resistance was enhanced by the addition of AUG and ribosomes to the above reaction mixture.

Acyltransferases↗
PubMed1981

A 56,000-dalton renin-binding protein in hog kidney is an endogenous renin inhibitor.

Renin-binding protein (RBP) in hog kidney was characterized and identified as a renin inhibitor. The molecular weight (Mr) of rBP is 56,000 when estimated by gel filtration. Its isoelectric point is 4.9. Upon binding to renin, it forms a renin.RBP complex with Mr = 113,000 as revealed by sedimentation equilibrium using an air-driven ultracentrifuge (Airfuge). The renin.RBP complex, formed by incubating hog kidney extract at 37 degrees C, is inactive when assayed with little dilution. On extensive dilution, however, this complex dissociates and acquires renin activity. The equilibrium between renin and renin.RBP complex and the equilibration rate were also studied by high performance liquid chromatographic gel filtration. The equilibrium was shifted to the complex, suggesting that RBP is present in an excess of renin in the kidney. The complex was shown to dissociate during the gel filtration due to rapid equilibration. Therefore, the elution position of the complex varied depending on flow rates, thereby making it difficult to determine the Mr of the complex by gel filtration. The renin.RBP complex is unlikely to occur in the normal kidney because renin and RBP are localized in the granule and cytosol fractions, respectively. RBP may provide security against accidental rupture of renin granules under abnormal circumstances.

Animals↗
PubMed1981

Demonstration of the formation of renin and renin-binding protein complex using high-performance liquid chromatography.

A high-performance liquid chromatograph equipped with the newly developed gel, TSK G3000SW, was used to study the interaction between renin and renin-binding protein (RBP). Previously, the interaction could only be demonstrated after overnight gel chromatography in the presence of a non-physiological sulfhydryl reagent. However, this new high-speed gel chromatography provided a clear separation of renin and renin--RBP complex within 40 min. It also demonstrated that the renin--RBP complex was formed at 37 degrees C in the absence of sulfhydryl reagent. Theses results indicate that the binding protein may play an important role in blood pressure regulation.

Animals↗
PubMed1981

Totally inactive renin zymogen and different forms of active renin in hog brain tissues.

The nature of the activable form of renin in the kidney and other tissues has not been clear. Its identification and isolation from kidney have been hampered by rapid activation due to high levels of proteases. Using a pepstatin-Sepharose column, which distinguishes inactive renin from the active enzyme, evidence was obtained for the presence of a totally inactive zymogenic precursor of renin in the pituitary, pineal, and other regions of hog brain. The precursor has an approximate molecular weight of 50,000 and conversion to the active enzyme causes reduction in molecular weight to 43,000. Conversion of this active enzyme to an active but high molecular weight form (60,000) was also observed when the pituitary extract was treated with thiol-blocking reagents. This result was interpreted to indicate the presence of a binding protein. This study has demonstrated that inactive renin zymogen is different from so-called active big renin, which is a complex of active renin and the binding protein.

Animals↗
PubMed1981

Promoter sequence of fibroin gene assigned by in vitro transcription system.

We have shown that the silk fibroin gene from Bombyx mori is faithfully transcribed in an in vitro transcription system of the HeLa cell extract prepared by the method of Manley et al. [Manley, J. L., Fire, A., Cano, A., Sharp, P. A. & Gefter, M. L. (1980) Proc. Natl. Acad. Sci. USA 77, 3855-3859]. Using this system and a series of deletion mutants of fibroin gene, we have assigned the promoter sequence of fibroin gene. The 5' boundary of the promoter is around nucleotide position -29, indicating that most of the T-A-T-A-A-A-A sequence (-30 to -24) is essential for the promoter function, where the transcription initiation point of fibroin gene is assigned as nucleotide position +1 [Tsuda, M., Ohshima, Y. & Suzuki, Y. (1979) Proc. Natl. Acad. Sci. USA 76, 4872-4876]. The 3' boundary is around nucleotide position +6. However, to support the efficient, faithful transcription, some additional (more than 26 but less than 41) nucleotides of nonspecific origin are required at the 5' side of -29. Functions ascribed to the promoter region are discussed.

Animals↗
PubMed1981

Relationship between methylation of adenine near the 3' end of 16-S ribosomal RNA and the activity of 30-S ribosomal subunits.

The relationship between methylation of adenine near the 3' end of 16-S ribosomal RNA and the activity of 30-S ribosomal subunits has been studied using 30-S subunits from kasugamycin-sensitive and kasugamycin-resistant bacteria. Analysis of the proteins of 30-S subunits by gel electrophoresis showed that the content of protein S1 in 30-S subunits from a kasugamycin-resistant strain was smaller than that in 30-S subunits from the parent strain. Although polyphenylalanine-synthetic activity of 30-S subunits from a kasugamycin-resistant strain previously methylated by a methylase purified from Escherichia Q13 was nearly equal to that of untreated 30-S subunits, both phenylalanine-synthetic activity and the content of protein S1 in the 30-S particles reconstituted from 23-S core particles and split proteins from the kasugamycin-resistant strain increased by prior methylation of 23-S core particles by the methylase. These results suggest that methylation of adenine near the 3' end of 16-S rRNA induces an increase of polypeptide-synthetic activity by the acceleration of binding of protein S1 to S1-depleted 30-S subunits.

Adenine↗
PubMed1981

Decrease in the S1 protein of 30-S ribosomal subunits in polyamine-requiring mutants of Escherichia coli grown in the absence of polyamines.

The reason for the decrease of polypeptide-synthetic activity of 30-S ribosomal subunits obtained from two polyamine-requiring mutants of Escherichia coli, grown in the absence of polyamines, has been studied by analyzing the total and split proteins of 30-S subunits by disc gel and slab gel electrophoresis. It was concluded that the decrease of S1 protein in 30-S subunits was responsible for the decrease of polypeptide synthesis in polyamine-requiring mutants of E. coli grown in the absence of polyamines.

Electrophoresis, Polyacrylamide Gel↗