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Biomedical subjects

M Noda

Publications and source records attributed to M Noda.

At least 505 records · Page 28Linked to original sources

Sulfide concentrations in postmortem mammalian tissues.

Postmortem changes in sulfide concentrations in body tissues were examined in autopsied rats exposed to hydrogen sulfide concentrations of 550 to 650 ppm, and in nonexposed rats and humans. Analyses were made by gas chromatography, following an extractive alkylation. Sulfide concentrations in the blood, liver, and kidneys of rats increased in both the exposed and nonexposed groups, depending on the lapse of time after death. On the other hand, the lung, brain, and muscle showed little or no change in sulfide concentration with elapse of time after death. The data obtained from human tissues were almost the same as those for rats, except data for blood, in which no or little increase of sulfide was observed.

Animals↗

[A case of miliary tuberculosis with prolonged high fever for more than 2 months under antituberculous therapy].

A 28 year-old male was admitted to our hospital with persistent cough and high fever. He was diagnosed to have miliary tuberculosis by the transbronchial lung biopsy specimen and tuberculous choroidal lesions in the ocular fundus. Antituberculosis therapy was immediately started. In spite of the fact that the bacilli were sensitive to the antituberculosis drugs used and he had no other complications, high fever persisted and lasted for more than 2 months. When tuberculosis is suspected, and antituberculosis treatment is tried to observe its clinical response, the presence of similar cases mentioned above should be taken into consideration.

Adult↗

[The treatment, course and prognosis of sarcoidosis cases].

Sarcoidosis is a disorder with a highly variable prognosis. Although spontaneous cure is common, a small number of patients become progressively worse. In this study, we analysed 433 patients with sarcoidosis who presented to our institute. Twenty-seven patients (6.2%) of them developed serious morbidity. We studied the clinical course, prognosis and use of steroid therapy in those 27 patients. Eight (29.6%) of the 27 patients developed severe disability during their clinical course, in spite of their mild clinical symptoms and findings at first presentation. Therefore, clinical symptoms and findings, such as ocular disorders, ECG abnormalities, negative reaction to PPD, serum ACE values and lymphocyte count are not always useful markers for the prognosis of sarcoidosis. The relationship between maximum serum ACE values during the course and the duration of the active phase was investigated in 93 patients who were followed throughout their course of the disease. Improvement occurred more often within 5 years in the patients with DR5(+) HLA class II or DRw53(-) compared to patients with DR5(-) or DRw53(+). Using various combinations of specific antigens, the following 5 groups revealed good prognoses, frequently improving within 5 years, 1) DR5(+) and DR4(-), 2) DR5(+) and DRw53(-), 3) DR5(+), DR4(-) and DR8(-), 4) DR5(+), DR4(-) and DR9(-), 5) DR5(+), DR4(-), DR8(-) and DR9(-). HLA class II antigens may also play an important role in the prognosis of sarcoidosis. Since relapses almost always occurred after cessation of steroid therapy, the duration of treatment should be as long as possible and the dosage should also be tapered carefully.

Adolescent↗

[Surgical treatment of aortic arch aneurysm associated with the aberrant right subclavian artery].

A 64-year-old man, who had an aneurysm of aortic arch associated with the aberrant right subclavian artery, was treated successfully. He was pointed out to have an aneurysm of aortic arch three years ago. Three years later angiograms and computed tomography revealed that it became larger compared with the initial finding. He underwent a replacement of the aortic arch using a woven Dacron graft under open distal method. Aberrant subclavian artery was not involved in the aneurysm. But because the left subclavian artery was involved in it, a woven Dacron graft was interposed between the ascending aorta and left subclavian artery. Postoperative course was uneventful and there were no complications.

Aorta, Thoracic↗

[Significance of inferior ST segment changes in acute anterior myocardial infarction--relationship between the distribution of left anterior descending artery and concomitant ischemia of the inferior wall].

The significance of inferior ST segment changes was studied in 23 patients with acute anterior myocardial infarction by the distribution of the left anterior descending artery (LAD) after percutaneous transluminal coronary recanalization. In 9 patients (Group A) LAD supplied the anterior wall of the left ventricle up to or including the apex but did not reach the inferior wall; in 8 patients (Group B) it continued beyond the apex onto the inferior wall of the left ventricle with well developed collateral circulation; in 6 patients (Group C) it continued beyond the apex onto the inferior wall of the left ventricle with less-developed or no collateral circulation. Thallium-201 scintigraphy and contrast left ventriculography showed that inferior myocardial ischemia was significantly more prominent in Group C than Group A. These results were consistent with coronary anatomy. Inferior ST segment was significantly more depressed in Group A with no concomitant inferior wall ischemia, than in Group C with concomitant inferior wall ischemia (maximal inferior ST segment change: -1.7 +/- 1.1; 0.8 +/- 1.7 mm, respectively; p less than 0.02). In Group A inferior ST segment was depressed in all 6 patients with lateral ST segment elevation, but it was depressed in only one of 3 patients with no lateral ST segment change. Lateral ST segment elevation tended to cause inferior ST segment depression. This study indicates that the inferior ST segment changes in patients with acute anterior myocardial infarction depend on concomitant ischemia of the inferior wall of the left ventricle by the distribution of LAD and the lateral ST segment changes.

Adult↗

A single point mutation confers tetrodotoxin and saxitoxin insensitivity on the sodium channel II.

A single point mutation of the rat sodium channel II reduces its sensitivity to tetrodotoxin and saxitoxin by more than three orders of magnitude. The mutation replaces glutamic acid 387 with a glutamine and has only slight effects on the macroscopic current properties, as measured under voltage-clamp in Xenopus oocytes injected with the corresponding cDNA-derived mRNA.

Amino Acid Sequence↗

Differential regulation of three sodium channel messenger RNAs in the rat central nervous system during development.

The levels of the mRNAs encoding sodium channels I, II and III in various regions of the developing rat central nervous system (from embryonal day 10 to postnatal day 90) have been examined by blot hybridization analysis with specific probes. The three sodium channel mRNAs exhibit different temporal and regional expression patterns. The expression of sodium channel I mRNA rises after a lag phase to adult levels during the second and third postnatal weeks with stronger increases in caudal regions of the brain and in spinal cord. Sodium channel II mRNA increases steadily until the first postnatal week, keeping high adult levels in rostral regions of the brain or reaching low adult levels after the second postnatal week in most caudal regions of the brain and in spinal cord; cerebellum shows low levels during the first two postnatal weeks but high adult levels. In all regions, sodium channel III mRNA attains maximum levels around birth and decreases during the first and second postnatal weeks to reach variable low adult levels. These results suggest that sodium channel III is expressed predominantly at fetal and early postnatal stages and sodium channel I predominantly at late postnatal stages, whereas sodium channel II is expressed throughout the developmental stages studied with greater regional variability.

Animals↗

Activation of immobilized, biotinylated choleragen AI protein by a 19-kilodalton guanine nucleotide-binding protein.

Cholera toxin catalyzes the ADP-ribosylation that results in activation of the stimulatory guanine nucleotide-binding protein of the adenylyl cyclase system, known as Gs. The toxin also ADP-ribosylates other proteins and simple guanidino compounds and auto-ADP-ribosylates its AI protein (CTA1). All of the ADP-ribosyltransferase activities of CTAI are enhanced by 19-21-kDa guanine nucleotide-binding proteins known as ADP-ribosylation factors, or ARFs. CTAI contains a single cysteine located near the carboxy terminus. CTAI was immobilized through this cysteine by reaction with iodoacetyl-N-biotinyl-hexylenediamine and binding of the resulting biotinylated protein to avidin-agarose. Immobilized CTAI catalyzed the ARF-stimulated ADP-ribosylation of agmatine. The reaction was enhanced by detergents and phospholipid, but the fold stimulation by purified sARF-II from bovine brain was considerably less than that observed with free CTA. ADP-ribosylation of Gsa by immobilized CTAI, which was somewhat enhanced by sARF-II, was much less than predicted on the basis of the NAD:agmatine ADP-ribosyltransferase activity. Immobilized CTAI catalyzed its own auto-ADP-ribosylation as well as the ADP-ribosylation of the immobilized avidin and CTA2, with relatively little stimulation by sARF-II. ADP-ribosylation of CTA2 by free CTAI is minimal. These observations are consistent with the conclusion that the cysteine near the carboxy terminus of the toxin is not critical for ADP-ribosyltransferase activity or for its regulation by sARF-II. Biotinylation and immobilization of the toxin through this cysteine may, however, limit accessibility to Gsa or SARF-II, or perhaps otherwise reduce interaction with these proteins whether as substrates or activator.

Biotin↗

ADP-ribosylation of cell membrane proteins by staphylococcal alpha-toxin and leukocidin in rabbit erythrocytes and polymorphonuclear leukocytes.

Staphylococcal alpha-toxin resulted in ADP-ribosylation of the 37 and 41 kDa proteins of a membrane preparation from rabbit erythrocytes. In the presence of 100 microM GTP, the toxin ADP-ribosylated proteins of 54 and 59 kDa and potentiated ADP-ribosylation of the 37 and 41 kDa forms. GTP had no effect on ADP-ribosylation of membrane proteins in the absence of alpha-toxin. Incubation of a membrane preparation of rabbit polymorphonuclear leukocytes with the S and F components of staphylococcal leukocidin resulted in ADP-ribosylation of the 37 and 41 kDa proteins, respectively. Furthermore, the 37, 41, 54 and 59 kDa proteins were ADP-ribosylated by leukocidin in the presence of GTP. The ADP-ribosylation of these proteins was observed to be dependent on the incubation time and toxin dose and was abolished by prior boiling. Addition of agmatine did not attenuate ADP-ribosylation of these proteins. These results demonstrate that staphylococcal alpha-toxin and leukocidin possess ADP-ribosyltransferase activities which are potentiated by GTP and suggest that ADP-ribosylation reactions are responsible for development of the cytolytic activities of these staphylococcal toxins.

Agmatine↗

Structural parts involved in activation and inactivation of the sodium channel.

Structure-function relationships of the sodium channel expressed in Xenopus oocytes have been investigated by the combined use of site-directed mutagenesis and patch-clamp recording. This study provides evidence that the positive charges in segment S4 are involved in the voltage-sensing mechanism for activation of the channel and that the region between repeats III and IV is important for its inactivation.

Action Potentials↗

A ras-related gene with transformation suppressor activity.

A 1.8 kb cDNA clone, Krev-1, with revertant-inducing activity on Kirsten sarcoma virus-transformed NIH/3T3 cells, has been isolated from a human fibroblast cDNA expression library. In Krev-1 transfectants, there is a correlation between the levels of specific mRNA and the degrees of suppression of the transformed phenotype. The cDNA encodes a protein of 21,000 daltons that unexpectedly shares around 50% amino acid identities with ras proteins. The Krev-1 homologs are found in mouse, rat, and chicken DNA, and their transcripts are ubiquitously expressed in many rat organs. Thus, the Krev-1 gene seems to play an important role(s) in a wide variety of tissues, and may be involved in the negative growth regulation of certain cell types.

Amino Acid Sequence↗

Participation of a guanine nucleotide-binding protein cascade in cholera toxin activation of adenylate cyclase.

Guanine nucleotide-binding (G) proteins are involved in several transmembrane signaling systems. Choleragen (cholera toxin) activates adenylate cyclase by catalyzing the ADP-ribosylation of Gs alpha, the stimulatory G protein of the cyclase system. This reaction is enhanced by another guanine nucleotide-binding protein termed ADP-ribosylation factor or ARF that was purified from bovine brain membranes [R. A. Kahn and A. G. Gilman, Journal of Biological Chemistry (1986) 261, 7906-7911]. It was recently found that this ARF also increases the NAD:agmatine and NAD:protein ADP-ribosyltransferase, NAD glycohydrolase and auto-ADP-ribosylation activities of the toxin. We have purified and characterized two soluble proteins from bovine brain that act in a similar fashion to enhance choleragen activity in each of these reactions. The membrane and soluble factors are all proteins of approximately 19 kDa that require GTP or GTP analogues for activity and are ADP-ribosylated by the toxin. The ARF proteins apparently interact directly with choleragen in a GTP-dependent fashion to increase its catalytic activity and thus are part of a G protein cascade through which the toxin activates adenylate cyclase. The physiological function of the ARF proteins, as well as their possible relationships to the ras oncogene products and/or the family of G proteins that includes Gs alpha, remains to be determined.

ADP-Ribosylation Factors↗

Detection of genes with a potential for suppressing the transformed phenotype associated with activated ras genes.

Seven morphologically nontransformed (flat) revertants with reduced tumorigenicity in vivo have been isolated from populations of Kirsten sarcoma virus-transformed NIH 3T3 cells transfected with a cDNA expression library of normal human fibroblasts. Each revertant harbors 1-10 recombinant plasmids per cell and retains a rescuable transforming virus as well as high level expression of v-Ki-ras-specific RNA and the viral oncogene product, p21v-Ki-ras. Transformed phenotypes are suppressed in cell hybrids generated by fusing each revertant to v-Ki-ras-transformed NIH 3T3 cells. From two of the revertant lines, plasmids capable of giving rise to flat secondary transfectants have been recovered. Thus, in some, if not all, of the revertants, transfected cDNAs seem to be responsible for the suppression of specific transformed phenotypes.

Animals↗

Isolation and immunological properties of adenosine kinase.

Bovine liver adenosine kinase is a 43 kDa protein that catalyzes the transfer of phosphate from GTP or ATP to adenosine. Its immunological properties were compared to other GTP-binding proteins of approximately 40 kDa, in particular those involved in signal transduction, such as Gs and Gi, the stimulatory and inhibitory regulatory proteins of adenylyl cyclase, Gt, from the visual excitation system, and Go, a similar protein of unknown function. Antibodies elicited in rabbits against adenosine kinase did not significantly cross-react with other guanyl nucleotide-binding proteins. Antibodies against the other GTP-binding proteins did not react with adenosine kinase. Thus these GTP-binding proteins do not exhibit immunological cross-reactivity.

Adenosine Kinase↗

Transcriptional regulation of osteopontin production in rat osteoblast-like cells by parathyroid hormone.

Osteopontin (OP) or bone sialoprotein is a recently characterized extracellular matrix protein which is abundant in bone and is produced by osteoblasts. Parathyroid hormone (PTH) is a potent calcitropic hormone which regulates osteoblastic function including the synthesis of extracellular matrix proteins. This study examines the effect of human PTH (hPTH-[1-34]) on the expression of this novel protein in rat osteoblast-like cells. hPTH(1-34) significantly decreased the amount of OP in culture media of the rat osteoblastic osteosarcoma cell line, ROS 17/2.8, detected by Western immunoblot analysis. hPTH(1-34) also suppressed the steady-state level of OP mRNA two- to threefold with an ED50 of approximately 3 X 10(-10) M. This inhibition was detectable at 24 h, reached its nadir at 48 h, and lasted at least up to 96 h. The hPTH(1-34) effects were mimicked by isobutylmethylxanthine, cholera toxin, 8-bromo-cAMP, forskolin, and isoproterenol. hPTH(1-34) suppressed by two- to threefold the rate of OP gene transcription, estimated by nuclear run-on assays. The suppression of OP mRNA levels by hPTH(1-34) was also seen when basal levels were increased by transforming growth factor type beta, or 1,25-dihydroxyvitamin D3, or were decreased by dexamethasone. A similar decrease in the steady-state level of OP mRNA by hPTH(1-34) was also observed in primary cultures of osteoblast-enriched cells from fetal rat calvaria. These findings indicate that hPTH(1-34) suppresses the production of the novel extracellular matrix protein, OP, in osteoblasts at least in part through transcriptional control.

1-Methyl-3-isobutylxanthine↗

Fibroblast growth factor enhances type beta 1 transforming growth factor gene expression in osteoblast-like cells.

Fibroblast growth factor (FGF) and type beta transforming growth factor (TGF beta) are potent modulators of proliferation and differentiation in many types of cells. TGF beta acts in an autocrine manner, and the regulation of TGF beta gene expression is one of the crucial events in the control of cellular functions. This study examines FGF regulation of TGF beta 1 gene expression in osteoblast-like cells. Bovine basic FGF (bFGF) increased the steady-state level of 2.5-kb TGF beta 1 mRNA two- to threefold in rat osteosarcoma (ROS17/2.8) cells in a dose-dependent manner, starting at 0.1 ng/ml. The increase of the message was detectable within 3 h after the addition of bFGF, peaked at 6 h, and lasted at least up to 48 h. This effect was blocked by a protein kinase inhibitor, K252a, indicating the involvement of phosphorylation. bFGF increased the rate of TGF beta 1 gene transcription estimated by nuclear run-on assay, while the stability of TGF beta 1 mRNA was not altered. bFGF increased the TGF beta activity in the conditioned media, estimated by DNA synthesis inhibition assay using mink lung epithelial (CCL-64) cells. Parathyroid hormone reduced the abundance of TGF beta 1 mRNA in ROsS17/2.8 cells and opposed the bFGF effect on TGF beta 1 mRNA. bFGF also increased the steady-state level of TGF beta 1 mRNA in mouse calvaria-derived MC3T3E1 and human osteosarcoma SaOS-2 cells. These findings indicate that FGF enhances the expression of TGF beta 1 gene in osteoblast-like cells and point to the tight relationship of the two growth factors involved in the control of cellular functions.

Animals↗

Control mechanism of the Escherichia coli K-12 cell cycle is triggered by the cyclic AMP-cyclic AMP receptor protein complex.

The role of cyclic AMP (cAMP) in the cell cycle of Escherichia coli K-12 was studied in three mutant strains. One was KI1812, in which the cya promoter is replaced by the lacUV5 promoter. In KI1812, isopropyl-beta-D-thiogalactopyranoside induced the synthesis of cya mRNA, and at the same time cell division was inhibited and short filaments containing multiple nuclei were formed. The other strains were constructed as double mutants (NC6707 cya sulB [ftsZ(Ts)] and TR3318 crp sulB [ftsZ(Ts)]). In both double mutants, filamentation was repressed at 42 degrees C, but it was induced again by addition of cAMP in strain NC6707 and introduction of pHA7 containing wild-type crp in TR3318. These results indicate that lateral wall synthesis in the E. coli cell cycle is triggered by the cAMP-cAMP receptor protein complex.

Cell Cycle↗