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M Hirono

Publications and source records attributed to M Hirono.

At least 55 records · Page 3Linked to original sources
PubMed1991

Drastic change in the level of actin mRNA in the course of synchronous division in Tetrahymena.

Change in actin mRNA level was investigated in the course of synchronous division in Tetrahymena induced by intermittent heat treatment. The level of actin mRNA decreased from just after the end of the heat treatment (EHT) to 45 min after EHT, and then promptly increased before synchronous division at 75 min after EHT. In contrast, levels of the total RNA and mRNAs of Tetrahymena calmodulin and calcium-binding protein of 25 kDa (TCBP-25) increased gradually from EHT to synchronous division. Drastic change in mRNA level before synchronous division seems to be unique to actin mRNA. From the effects of actinomycin D (50 micrograms/ml) on both synchronous division and actin mRNA level, the increase in actin mRNA level starting from 45 min after EHT is speculated to be prerequisite for the oncoming synchronous division. The results of a nuclear run-off experiment supported the above speculation.

Actins↗
PubMed1990

Purification and characterization of Tetrahymena profilin.

We subjected Tetrahymena cell extract to a poly(L-proline) affinity column for isolating profilin and obtained a protein of 12.8 kDa. Purified 12.8 kDa protein dose-dependently inhibited the polymerization of Tetrahymena actin more strongly than that of rabbit skeletal muscle actin. Because the 12.8 kDa protein fulfills properties common to profilins, the protein is considered to be Tetrahymena profilin. The present paper is the first report of the isolation of an actin-binding protein from Tetrahymena.

Actins↗
PubMed1990

[Multi-drug chemotherapy for patients with peritonitis carcinomatosa associated with ascites].

Between 1973 and 1987, 257 patients with ascites were seen in our divisions and 101 deaths due to cancer out of those who received multi-drug anticancer chemotherapy were surveyed: 1) They consisted of 45 ovarian cancers, 15 uterine corpus cancers, 5 uterine cervical cancers and 36 unknown primary cancers, or cancers other than gynecologic malignancies. 2) Survival time from the time of aspiration of ascites tended to be longer in four years from 1977 and 1981 than in four years from 1973. 3) The survival time was different in each patient groups having various combination chemotherapy and the longest was seen in the group of patients who received THP-ADM and CDDP-containing regimen as the next. 4) Patients survived for the longest period when a total amount of ascites less than 100 ml was aspirated and patients whose ascites was drained out more than 50,000 ml were the next longest survivors. 5) Clinical efficacy by multi-drug chemotherapy for malignant ascites was possibly predicted by our drug sensitivity assay by using primary cultured cancer cells.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

Tetrahymena actin: copolymerization with skeletal muscle actin and interactions with muscle actin-binding proteins.

We have previously shown that actin from Tetrahymena pyriformis has a very divergent primary structure (Hirono, M., Endoh, H., Okada, N., Numata, O., & Watanabe, Y. (1987) J. Mol. Biol. 194, 181-192) and that though it shares essential properties with skeletal muscle actin, it does not interact at all with phalloidin or DNase I (Hirono, M., Kumagai, Y., Numata, O., & Watanabe, Y. (1989) Proc. Natl. Acad. Sci. U.S. 86, 75-79). In this study, we investigated the copolymerization of this actin with skeletal muscle actin by direct observation of the heteropolymers formed from the two actins by means of electron microscopy. We also examined the binding of actin-binding proteins from skeletal muscle or smooth muscle to Tetrahymena actin by means of a cosedimentation assay. The results show that (i) Tetrahymena actin copolymerizes with skeletal muscle actin and that (ii) muscle myosin subfragment 1 binds to it in the absence of ATP, like skeletal muscle actin. However, it was also shown that (iii) muscle alpha-actinin hardly binds to Tetrahymena actin and that (iv) muscle tropomyosin does not bind to it at all. The results show that Tetrahymena actin has both properties similar and dissimilar to those of skeletal muscle actin.

Actinin↗
PubMed1989

The role of the carboxyl-terminal 6 amino acid extension of human TSH beta subunit.

The nucleotide sequence of human thyroid stimulating hormone (hTSH) gene can encode a protein of 138 amino acids. However, the mature polypeptide is lacking 6 amino acids of the carboxyl-terminus (C-terminus), suggesting posttranslational cleavage of these residues. To analyze a possible function of these 6 amino acids, we expressed two hTSH beta cDNAs with or without the 6 codons for C-terminal extension, together with alpha subunit cDNA in CHO cells, and determined the amino acid sequence of C-terminus of hTSH beta. hTSH beta propeptides without C-terminal extension were glycosylated, associated with alpha subunit and secreted, as normal propeptides were, and its heterodimer with alpha subunit showed normal TSH bioactivity in FRTL-5 bioassay. These data indicate that the 6 amino acid C-terminal extension is not necessary for the hTSH maturation in the process of the biosynthesis and for its bioactivity.

Amino Acid Sequence↗
PubMed1989

The histological assessment and evaluation of a 4 day subrenal capsule assay by the percentage inhibition of DNA/protein.

A four day subrenal capsule assay was investigated in order to determine its ability to clinically predict tumor chemosensitivity. To establish more objective and accurate evaluation criteria, a histological assessment and measurement of the DNA and protein content of excised tumor implants was conducted in ddY mice. The histological studies provided qualitative results concerning the percentage of cancer cells in the xenograft, the number of mitoses, the amount of necrosis, and the extent of lymphocytic infiltration. The DNA content was measured by a modified version of the Schmidt-Thannhauser-Schneider method and the protein content was estimated using the Bio-Rad protein assay. The percentage of cancer cells in the xenograft correlated poorly with the relative increase in tumor size, weight and the percentage inhibition of DNA/protein (per cent DNA/protein), however, the per cent DNA/protein correlated well with the clinical effects in 85.7 per cent of the tumors studied. Moreover, the histological assessment information was only consistent with those results obtained for per cent DNA/protein in the control group.

Animals↗
PubMed1989

Purification of Tetrahymena actin reveals some unusual properties.

Actin from Tetrahymena pyriformis has been purified by monitoring the presence of the actin gene product with an antiserum against a synthetic N-terminal peptide deduced from the nucleotide sequence of the Tetrahymena actin gene that we cloned previously. This highly purified Tetrahymena actin shares many essential properties with ubiquitous actin, including ion-dependent polymerization to microfilaments, binding with muscle heavy meromyosin to form arrowheads, and activation of the Mg2+-ATPase of muscle myosin subfragment 1. On the other hand, some properties of this purified Tetrahymena actin clearly differ from those of muscle actin: (i) Tetrahymena actin has 8 times less ability to activate the Mg2+-ATPase of muscle myosin subfragment 1 than muscle actin; (ii) Tetrahymena actin did not bind to phalloidin at all; (iii) Tetrahymena actin did not inhibit DNase I activity at all. In general, Tetrahymena actin has very unusual properties when compared to other actins described so far. This actin is expected to provide important clues for elucidating problems concerning the relationships between the structural and functional domains in an actin molecule.

Actins↗
PubMed1989

[Progression of a new lesion after percutaneous transluminal coronary angioplasty--report of a case].

A-62-years-old man was admitted our hospital because of angina at rest and during effort. Coronary angiography revealed 25% fixed stenosis in Seg. 6, 90% in Seg. 7, 75% in Seg. 10, and 50% in Seg. 12. Percutaneous transluminal angioplasty was performed for segment 7 and complete revascularization was obtained finally. Two and a half months later, progressive lesion occurred in the segment proximal to the angioplasty site (Seg. 6). The manipulation of the guiding catheter in the coronary artery proximal to the PTCA site might have developed atherogenesis in this area. So we must consider the possibilities of both restenosis and new lesions when one has the recurrence of ischemic symptoms after coronary angioplasty.

Angina Pectoris↗
PubMed1987

Production of human thyroid-stimulating hormone in Chinese hamster ovary cells.

Human thyroid-stimulating hormone (hTSH) has been produced in Chinese hamster ovary (CHO) cells co-transformed with two plasmids: one carrying the alpha subunit cDNA with mouse dihydrofolate reductase gene and the other carrying hTSH beta subunit cDNA. Each cDNA was driven to expression under the control of SV40 early promoter. hTSH and its alpha subunit were secreted into culture media, and their secretion increased with exposure of the cells to increasing concentrations of methotrexate. Gel filtration analysis revealed that the molecular size of the hTSH was the same as that of natural hTSH. Furthermore, the CHO cell-produced hTSH elevated the cyclic AMP level in the rat thyroid cell line FRTL-5 in the same manner as natural hTSH does.

Animals↗
PubMed1987

Tetrahymena actin. Cloning and sequencing of the Tetrahymena actin gene and identification of its gene product.

Actin is ubiquitous in eukaryotes, nevertheless its existence has not yet been clearly proven in Tetrahymena. Here we report the cloning and sequencing of an actin gene from the genomic library of Tetrahymena pyriformis using a Dictyostelium actin gene as a probe. The Tetrahymena actin gene has no intron. The predicted actin is composed of 375 amino acids like other actins and its molecular weight is estimated as 41,906. Both T. pyriformis and T. thermophila possess a single species of actin genes which differ in their restriction patterns. Northern hybridization analysis revealed that the actin gene was actively transcribed in vivo. To detect the gene product, we synthesized an N-terminal peptide of the deduced sequence and prepared its antibody. Using an immunoblotting technique, we identified Tetrahymena actin on a two-dimensional gel electrophoretic plate. The actin spot migrated near an added spot of rabbit skeletal muscle actin, but clearly differed from the latter in its isoelectric point and apparent molecular weight. The primary structure of Tetrahymena actin shares about 75% homology equally with those of other representative actins. This value is extremely low as a homology rate between known actins. Tetrahymena actin diverges not only in relatively variable regions of other actins, but also in relatively constant regions. The hydrophilicity levels of two regions (residues 190 to 200 and residues 225 to 235) are also quite different between the Tetrahymena actin and skeletal muscle actin. Thus, we conclude that actin is present in Tetrahymena, but it is one of the most unique actins among the actins known hereto.

Actins↗
PubMed1987

Intestinal metaplasia of the stomach confined to the fundic gland area. Report of two cases.

Two patients with intestinal metaplasia of the stomach, whose distribution was exclusively confined to the fundic gland area, are presented herein. The first, a 51-year-old male, had been treated for pernicious anemia for 14 years when he was found to have gastric cancer. His serum gastrin level was quite high, whereas his gastric acid output was markedly low. The polypoid cancer in the fornix of the stomach, which had been removed endoscopically, revealed tubular adenocarcinoma with its invasion limited to the mucosa. The resected stomach showed no residual carcinoma but had numerous minute foci of intestinal metaplasia, diffusely distributed but exclusively confined to the fundic gland area, by macroscopic observation using the leucine aminopeptidase-alkaline phosphatase double staining method. The intestinal metaplasias were all of the complete type, and the parietal and chief cells were almost completely lost. The second patient, a 76-year-old male without pernicious anemia, underwent total gastrectomy for two polypoid cancers in the body of the stomach. The resected specimens, in addition to two hyperplastic polyps in the transitional area, showed the same distribution of intestinal metaplasia as seen in the first patient.

Adenocarcinoma↗
PubMed1987

Tetrahymena actin: localization and possible biological roles of actin in Tetrahymena cells.

Though actin is ubiquitous in eukaryotes, its existence has not been clearly proven in Tetrahymena. Recently, we have succeeded in cloning and sequencing the Tetrahymena actin gene using a Dictyostelium actin probe (Hirono, M. et al. (1987) J. Mol. Biol. 194, 181-192). The primary structure of the Tetrahymena actin deduced from the nucleotide sequence of its gene is greatly divergent from those of other known actins, making it necessary to ascertain whether the predicted Tetrahymena actin is indeed an actin. In this paper, we investigated the localization of the predicted Tetrahymena actin by an immunofluorescence technique using antibody against its synthetic N-terminal peptide, in order to elucidate its possible biological roles. The results showed that immunofluorescence was localized in the division furrow of the dividing cell, and in the intranuclear filament bundles formed in cells exposed to heat shock or DMSO. In addition, the oral apparatus and the proximity of the cytoproct, which are organelles involved in endocytosis and exocytosis, respectively, also fluoresced. Thus, we conclude that the Tetrahymena actin we identified is indeed an actin and plays the same biological roles as ubiquitous actins do, although it is considerably divergent in its amino acid sequence.

Actins↗
PubMed1986

A cohort study on second malignancies in gastrectomized patients with gastric cancer. I. Second malignancies other than cancer of the gastric remnant.

In a retrospective cohort study, a total of 235 (2.32 per cent) second malignancies were clinically observed in 10,138 patients during the average 8.8-year follow-up period. The patients had undergone gastrectomy for gastric cancer during 1960-1975, in seven different institutions. This observed number was smaller than the expected one of 340.9 (p less than 0.01). Among the 235, cancers of the gastrointestinal tract (111) were the most frequent and followed by respiratory (54) and urogenital (25) cancers. Twelve cases of malignant lymphoma and five of leukemia were also noted. With regard to adjuvant chemotherapeutic agents such as mitomycin-C (MMC), 5-fluorouracil (5FU) or its derivative Tegafur, and cyclophosphamide (EDX), no significant differences in the rate of second malignancies were obtained between the chemotherapy and non-chemotherapy groups. The occurrence rate of second malignancies tended to be higher in the Billroth II group than in the Billroth I, the significance of which is yet to be determined.

Adult↗
PubMed1986

A cohort study on second malignancies in gastrectomized patients with gastric cancer. II. Second malignancies in the gastric remnant.

In a retrospective cohort study, a total of 22 (0.22 per cent) carcinomas of the gastric remnant were clinically observed, as second malignancies, in 7,672 patients during the average of a 9.4-year follow-up period. All had undergone distal subtotal gastrectomy for gastric cancer from 1960-1975 in seven different institutions. Of 22 carcinomas of the gastric remnant, 5 were at the anastomotic site, 14 distant from the anastomosis; the location was unknown in three. All five carcinomas of the anastomotic site occurred after Billroth II operation. Time intervals between the first operation and the occurrence of second cancer varied from two to 21 years. With regard to the administration of adjuvant chemotherapeutic agents such as mitomycin-C (MMC), 5-fluorouracil (5FU) or its derivative Tegafur, no significant differences in the rate of second malignancies were obtained between the chemotherapy and non-chemotherapy groups. The occurrence rate of cancer of the gastric remnant between Billroth I and Billroth II groups showed no statistically significant difference, although it did tend to be slightly higher in the latter.

Adult↗
PubMed1986

[Secondary malignancies after gastrectomy for gastric cancer].

In patients who have undergone gastrectomy for gastric cancer, the use of adjuvant chemotherapy has now become very widespread in Japan. The possibility of secondary malignancies in these patients emerges as a long-term effect of these therapeutic agents. This collaborative study was done to examine the possibility of secondary malignancies resulting from both operative methods and anticancer agents at the surgical departments of seven major institutions in Japan. The study was carried out using questionnaires for all patients with gastric cancer who had undergone gastrectomy between 1960 and 1975 in those hospitals and who had survived more than one year after gastrectomy. A total of 235 secondary malignancies (2.32%) were noted among 10,138 gastrectomized patients, and 22 cancers of the gastric remnant (0.29%) were recorded among 7,672 subtotal gastrectomized cases. Cancers suspected to be recurrent gastric cancer were all excluded. As to anticancer agents, Mitomycin C (MMC), 5-Fluorouracil (5-FU) or Tegafur and Cyclophosphamide (EDX) were analyzed. The occurrence rate of secondary cancers in gastric cancer patients was calculated in many instances by dividing the actual number of secondary cancers by the total time at risk (person-years). Patients with gastric cancer who had undergone gastric resection revealed a lower incidence of secondary malignancies than had been expected. The most common secondary cancers were those occurring in the digestive system, followed by those of the respiratory system. With regard to MMC, 67 secondary cancers (2.21%) occurred in the MMC group and 168 cancers (2.36%) in the non-MMC group. Although the overall incidence of secondary cancers showed no difference between MMC and non-MMC groups, secondary cancers of the digestive system were less common in the MMC group than in the non-MMC group. A total of 22 cancers originated in the gastric remnant out of 7,672 subtotally resected stomachs. The interval between the first operation and cancer of the gastric remnant varied greatly without showing any detectable trend. Nine cancers were observed to involve the anastomotic site while 14 did not involve the anastomotic site. The incidence of cancer of the gastric remnant tended to be slightly higher with the Billroth II method than in the Billroth I method, but there was no difference in the site of secondary malignancy between the two groups.

Adult↗