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T Miwa

Publications and source records attributed to T Miwa.

At least 289 records · Page 16Linked to original sources
PubMed1987

Transcription termination and RNA processing in the 3'-end spacer of mouse ribosomal RNA genes.

The 3' termini of ribosomal RNA precursors from mouse FM3A cultured cells are mapped to eight sites within 625 bp downstream from the 3' terminus of 28 S rRNA. Three additional sites are mapped in liver RNA from C3H/He strain mice. Two of them, the sites at 570 bp and 625 bp are assumed to be termination sites in vivo, because they correspond to in vitro termination sites of RNA polymerase I, and 45 S RNAs having these 3' termini decay with kinetics distinct from others. The amount of 45 S RNA having the 3' terminus at other sites is variable among several mouse strains, despite their having the same DNA sequence in these regions. The ability to produce 3' termini in these sites seems to follow Mendel's law of inheritance. Therefore, we postulate that these nine sites are RNA processing sites which are controlled genetically.

Animals↗
PubMed1987

CArG boxes in the human cardiac alpha-actin gene are core binding sites for positive trans-acting regulatory factors.

Positively acting, rate-limiting regulatory factors that influence tissue-specific expression of the human cardiac alpha-actin gene in a mouse muscle cell line are shown by in vivo competition and gel mobility-shift assays to bind to upstream regions of its promoter but to neither vector DNA nor a beta-globin promoter. Although the two binding regions are distinctly separated, each corresponds to a cis region required for muscle-specific transcriptional stimulation, and each contains a core CC(A + T-rich)6GG sequence (designated CArG box), which is found in the promoter regions of several muscle-associated genes. Each site has an apparently different binding affinity for trans-acting factors, which may explain the different transcriptional stimulation activities of the two cis regions. Therefore, we conclude that the two CArG box regions are responsible for muscle-specific transcriptional activity of the cardiac alpha-actin gene through a mechanism that involves their binding of a positive trans-acting factor in muscle cells.

Actins↗
PubMed1987

Gestational protein-energy malnutrition affects the composition of developing skins of rat fetuses and their dams.

1. Various biochemical variables of the skins of rat dams and their fetuses in which protein-energy malnutrition was induced during pregnancy were analysed. 2. One group of dams was fed on a 200 g protein/kg diet as a control and the other was fed on a 60 g protein/kg diet as an experimental group. Each group of dams was fed from day 13 of gestation until day 22. 3. Water, protein and hexosamine concentrations of the fetal skins in the malnourished group were greater than those in the control group, whereas in the dams' skins, protein concentration was greater in the malnourished group than in the control group. 4. Extractability of collagen with neutral salt and pepsin showed no difference between the groups in the skins of fetuses and dams. The content of type III collagen in the fetal skin did not differ between the groups, but was increased in the malnourished dams' skins compared with that of the control group. 5. The present study showed that protein-energy malnutrition during pregnancy significantly affects the metabolism of the skin in both fetuses and their dams. Furthermore, the skins of fetuses and dams are structurally altered in different ways by this nutritional stress.

Animals↗
PubMed1987

Systemic amyloid arthropathy associated with multiple myeloma.

This is the first report of an autopsy case of systemic amyloid arthropathy associated with multiple myeloma in Japan. The patient was a 72-year-old male who had been suffering from multiple myeloma (IgA-lambda) with extensive arthropathy of the systemic joints. Autopsy examination revealed severe deposit of amyloid in the articular cavities of the systemic joints showing a feature of amyloidoma. Furthermore, numerous amyloid deposits were found in the wall of small blood vessels in the major organs. In the bone marrow, there were many atypical plasma cells and foamy cells both showing positive reaction for IgA and lambda light chain. No such atypical cells were observed in the other organs except for the bone marrow.

Aged↗
PubMed1987

Duplicated CArG box domains have positive and mutually dependent regulatory roles in expression of the human alpha-cardiac actin gene.

An upstream region from the transcription initiation site to -177 base pairs (bp) of the human alpha-cardiac actin gene directs the transient expression of a bacterial chloramphenicol acetyltransferase (CAT) gene only in muscle cells (A. Minty and L. Kedes, Mol. Cell. Biol. 6:2125-2136, 1986). We modified this promoter region by additional 5' deletions, linker-scanning mutations, and insertion-deletion mutations and demonstrated that the asymmetrical sequences in and adjacent to two CArG [for CC(A + T rich)6GG] motifs, located at -140 and -100 bp, play an important positive role in transcription. The significant impairment of transcriptional activity that accompanies the disruption of one CArG box region can be restored by either. This demonstrated that these two elements interact in a mutually dependent and similar manner. Furthermore, a DNA fragment that includes the CArG boxes had significant competitive activity for transcription directed by the alpha-cardiac actin promoter in an in vivo competition assay. We conclude that the two sequences around each CArG box may interact with the same class of trans-acting positive factor(s) and that these interactions may mediate muscle-specific expression. Each of the two CArG regions appears to be bound independently by such a positive factor(s), and the regions support high-level transcription in a synergistic manner. The transcriptional activity of this regulatory region is proportional to its distance from a TATA box (at -30 bp) and is strictly orientation dependent relative to the direction of transcription. Therefore this upstream region is not an enhancer but is a tissue-specific regulatory upstream element.

Actins↗
PubMed1987

Famotidine in the treatment of gastritis.

H2-receptor antagonists are widely used in the treatment of diseases such as gastric and duodenal ulcers, hemorrhage of the upper digestive tract, and the Zollinger-Ellison syndrome. However, the usefulness of H2-receptor antagonists in treating erosions and/or mucosal hemorrhages has not been established. A multicenter, double-blind, comparative trial was conducted to determine the effects of famotidine, a new H2-receptor antagonist, for such lesions. Patients received one of three oral doses (5, 10, or 20 mg) of famotidine twice daily for 2 weeks. The comparative efficacy and safety of the three dosages of famotidine in the treatment of lesions were evaluated, using an assessment of subjective symptoms, endoscopic findings, and adverse reactions. Symptoms, including epigastric pain, heartburn, and discomfort, were relieved in a substantial number of patients as early as 3 days after beginning treatment with famotidine. Moreover, less than 30% of patients complained of these symptoms after 2 weeks of famotidine therapy. There were no significant differences among the three dosages in relief of symptoms. Endoscopic assessment for the presence of erosion and hemorrhage after 1 and 2 weeks of famotidine treatment showed that the 10- and 20-mg doses were more effective in healing erosions and hemorrhages than was the 5-mg dose. After 2 weeks of treatment, 88.5% and 91.7% of the patients in the 10- and 20-mg dosage groups, respectively, did not have evidence of erosions or hemorrhages, compared with 73% of patients in the 5-mg group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Collagen and collagenase in ulcer tissue--1. The healing process of acetic acid ulcers in rats.

We have reported that collagenase activity of the gastric mucosa increased significantly in acetic acid ulcers of dogs. The present study revealed that acetic acid ulcers in showed that the active collagenase level in the ulcer tissue increased rapidly with a peak (412.5%) on the 3rd day after induction of the acetic acid ulcer. Thereafter, the collagenase activity levels decreased gradually by the 7th day and returned practically to the control levels by the 14th day. On the other hand, collagen (hydroxyproline content) decreased by the 7th day (-16.5%) and recovered by the 14th day after induction of the acetic acid ulcer. The peak of active collagenase on the 3rd day coincident with the maximum ulcer index, suggesting involvement of collagenase activity in ulceration. In addition, destruction and production of collagen are considered to take place not only at the base of the ulcer and its margin, but also along its circumference.

Acetates↗
PubMed1987

Endoscopic manometry of the sphincter of Oddi in dogs. Pharmacological effects of anticholinergic and selective antimuscarinic agents.

A dog model was used for direct measurement of the sphincter of Oddi using endoscopy. The effects of anticholinergic agents and a selective antimuscarinic agent on the canine sphincter of Oddi motility were studied. Manometric tracing at the canine sphincter showed rhythmical phasic contractions which were not affected by respiration. The mean values of the basal motility were as follows: the peak pressure was 61.5 +/- 2.2 (m +/- SE) cmH2O, trough pressure was 2.18 +/- 1.2 cmH2O, and the frequency was 17.4 +/- 0.2 waves/min. Intravenous administration of atropine sulfate, butropium bromide, butylscopolamine bromide and also pirenzepine significantly reduced the amplitude and frequency of canine sphincter contractions. From these results, it appeared that the cholinergic autonomic nervous system might be the one of the regulators of the canine sphincter of Oddi activity.

Ampulla of Vater↗
PubMed1986

Diluting segment in avian kidney. II. Water and chloride transport.

The mammalian-type nephrons of avian kidneys contain a Henle's loop that runs parallel to the collecting ducts and the vasa recta. Thus we examined whether the thick ascending limb (TAL) of Henle's loop of the avian kidney acts as a diluting segment by measuring water and Cl transport in the isolated and perfused TAL of the quail, Coturnix coturnix. The TAL showed a lumen-positive transepithelial voltage (Vt) (+9.4 +/- 0.4 mV, n = 28). Net water flux (Jv) was nearly zero when the TAL was perfused and bathed with isosmotic solution. When the osmotic gradient was imposed, Jv increased only slightly, and thus the osmotic water permeability (Lp) was low. Arginine vasotocin (AVT) added to the hyperosmotic bath did not alter either Jv, Lp, or Vt. Cl efflux (lumen to bath, 370.4 +/- 27.7 peq X mm-1 X min-1) was higher than Cl influx (bath to lumen, 98.6 +/- 14.3 peq X mm-1 X min-1) when measured in the different tubules. AVT showed no effect on Cl efflux. These results indicate that in the TAL of the quail osmotic water permeability is low while net Cl reabsorption is present, suggesting that the TAL functions as a diluting segment.

Animals↗
PubMed1986

Effects of ACNU and radiotherapy on malignant glioma.

A randomized clinical study of irradiation and irradiation combined with ACNU in the treatment of malignant gliomas was performed in order to determine if there was an enhancing therapeutic effect of ACNU given in addition to radiotherapy. An effect was defined as a reduction in tumor size, changes in neurological signs and performance status within 1 month after the completion of radiotherapy, or statistically improved survival times. Seventy-seven patients from 14 neurosurgical clinics were included in this validated study group. Radiotherapy with a total dose of 5000 to 6000 rads, given in 25 to 30 subdoses, was applied to the whole brain and to a generous field surrounding the tumor. Patients who were assigned to receive chemotherapy were given ACNU intravenously once or twice during radiotherapy at a dose of 100 mg/sq m of body surface area. The response rate (more than 50% reduction of the tumor size) was 13.5% in the group treated by radiotherapy alone and 47.5% in the group with radiotherapy and ACNU. The hematological toxicity was more severe in the group treated with radiotherapy and ACNU. Other toxicity was mild and acceptable. The survival rates of patients with astrocytoma grade III and glioblastoma multiforme at 36 months after the surgery were 48.9% and 0% for radiotherapy alone and 59.0% and 16.3% for radiotherapy plus ACNU, respectively. The differences between the survival curves were not significant at the p = 0.05 level. This study has demonstrated that, although the use of ACNU during radiotherapy suppressed malignant gliomas more than radiotherapy alone, the survival time was not extended significantly. It is necessary to continue to search for an effective chemotherapeutic regimen to prolong survival of patients with malignant gliomas.

Adolescent↗
PubMed1985

Presence of a limited number of essential nucleotides in the promoter region of mouse ribosomal RNA gene.

Point mutations are introduced into a mouse rDNA fragment containing the promoter region by a sodium bisulfite method and the mutants are tested for the ability of accurate transcription initiation in vitro. The results indicate that the change, G to A, at -7 completely eliminates the promoter activity, and those at -16 and at -25 decrease it to about 10% and 50%, respectively. On the other hand, the substitutions at +9, +4, -2, -9 and -39 do not alter the template activity significantly. It is concluded that there are limited but distinct nucleotides that are essential for the transcription initiation of this gene. This sort of absolute requirement for single specific bases is not reported in protein coding genes transcribed by RNA polymerase II. We propose that these rigid recognition signals which we have found are the molecular basis for the strong species-dependency of the transcription machinery of RNA polymerase I system. A model is presented in which a transcription factor interacts with the rDNA promoter from one side of the DNA double-helix with essential contacts at these bases.

Animals↗