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Biomedical subjects

K Irie

Publications and source records attributed to K Irie.

At least 181 records · Page 10Linked to original sources
PubMed1994

Oryzacystatin exogenously introduced into protoplasts and regeneration of transgenic rice.

Oryzacystatin (OC) is a proteinaceous cysteine proteinase inhibitor involved in the biodefense of rice seeds. To create transgenic rice plants with increased OC activity, we introduced an OC expressing vector into rice protoplasts and obtained transformed calli. The expression vector contained a bacterial inaA DNA fragment in the 3'-noncoding region as a tag to distinguish the introduced DNA from the intrinsic OC gene. The OC vector and a selection marker gene conferring hygromycin resistance were used together to transfect into rice protoplasts. A number of hygromycin-resistant calli were obtained and studied by polymerase chain reaction and genomic Southern blotting to find if the exogenous OC gene had been integrated. The calli were studied by northern blotting as well to examine mRNA expression. The results showed that integration and expression of the introduced OC gene occurred in 51% and 27%, respectively, of 156 subcultures from 15 hygromycin-resistant calli. As a final step, transgenic rice plants were regenerated from the calli expressing OC. Leaves and seeds from the plants had higher OC activities than those from nontransgenic plants.

Base Sequence↗
PubMed1994

Long-lasting ex vivo inhibition by perindopril of rat vascular response to angiotensin I.

The ex vivo effects of perindopril and enalapril, inhibitors of angiotensin-converting enzyme (ACE), were studied on rat aortae and perfused hearts to clarify the inhibition of vascular response to angiotensin I. The duration of the effects of these inhibitors was also studied. One hour after oral administration of perindopril (0.1-30 mg/kg) or enalapril (0.3-100 mg/kg), the aortae and hearts were isolated for the measurement of isometric force and coronary flow, respectively. In aortae, perindopril and enalapril dose-dependently inhibited the maximal contractions to angiotensin I (1-1000 nM). In isolated perfused hearts, the compounds inhibited the decrease in coronary flow induced by angiotensin I (100 ng). In other experiments, the inhibitory effects of perindopril lasted for 24 h in both aortae (3 mg/kg, p.o.) and hearts (10 mg/kg, p.o.). In contrast, the effects of enalapril disappeared within 6 h in aortae (3 mg/kg, p.o.) and 12 h in hearts (100 mg/kg, p.o.). These results demonstrate that oral administration of ACE inhibitors reduce the ex vivo vascular response to angiotensin I and suggest that perindopril is a longer-lasting inhibitor than enalapril on vascular contraction to locally generated angiotensin II.

Administration, Oral↗
PubMed1994

[A case of examination of skeletal remains--how many bodies did they come from?].

We examined skeletal remains, with the main intention of estimating how many bodies they had come from. The samples were a skull with defect of its base, an upper jaw, two lower jaws (No. 1, No. 2) and two skeletal bodies (No. 1: with no skull, No. 2: consisting mainly of the lower extremities). In examining the mutual relationship among them, we utilized adjustability between the skull and the lower jaws at the temporomandibular joint, and between the lower jaws and the upper jaw in the biting manner of their teeth. We concluded that the most probable combination was of two bodies, i.e. [skull + lower jaw No. 1 + skeletal body No. 1] and [upper jaw + lower jaw No. 2 + skeletal body No. 2]. Beside the above presentation, we did comment on several problems in personal identification and estimation of postmortem interval.

Adult↗
PubMed1993

A gene, SMP2, involved in plasmid maintenance and respiration in Saccharomyces cerevisiae encodes a highly charged protein.

The smp2 mutant of Saccharomyces cerevisiae shows increased stability of the heterologous plasmid pSR1 and YRp plasmids. A DNA fragment bearing the SMP2 gene was cloned by its ability to complement the slow growth of the smp2 smp3 double mutant (smp3 is another mutation conferring increased stability of plasmid pSR1). The nucleotide sequence of SMP2 indicated that it encodes a highly charged 95 kDa protein. Disruption of the genomic SMP2 gene resulted in a respiration-deficient phenotype, although the cells retained mitochondrial DNA, and showed increased stability of pSR1 like the original smp2 mutant. The fact that the smp2 mutant is not always respiration deficient and shows increased pSR1 stability even in a rho0 strain lacking mitochondrial DNA suggested that the function of the Smp2 protein in plasmid maintenance is independent of respiration. The SMP2 locus was mapped at a site 71 cM from lys7 and 21 cM from ilv2/SMR1 on the right arm of chromosome XIII.

Amino Acid Sequence↗
PubMed1993

A specific host factor binds at a cis-acting transcriptionally silent locus required for stability control of yeast plasmid pSR1.

A cis-acting locus, Z, of plasmid pSR1 functions in stable maintenance of the plasmid in the native host, Zygosaccharomyces rouxii. The Z locus was shown to be located in a 482 bp sequence in the 5' upstream region of an open reading frame, P, by subcloning various DNA fragments in a plasmid replicating via the ARS1 sequence of the Saccharomyces cerevisiae chromosome. Northern analysis revealed that the Z region is not transcribed in either the native host Z. rouxii or the heterologous host S. cerevisiae. The Z region is protected from micrococcal nuclease attack in Z. rouxii but not in S. cerevisiae, its protection depending on the product of the S gene encoded by pSR1. Gel retardation assays suggested that a factor present in nuclear extracts of Z. rouxii cells, irrespective of the presence or absence of a resident pSR1 plasmid, binds to a 111 bp RsaI-SacII sequence in the Z region. These findings suggest that a host protein binds to the Z locus and that the S product interacts with this DNA-protein complex and stabilizes pSR1.

Base Sequence↗
PubMed1993

99mTc-HMDP accumulation in a phyllodes tumor of the breast, a case report.

In a patient with breast tumor, 99mTc-HMDP accumulation in the tumor was recognized in evaluating bone metastasis. Surgery and histopathology revealed that the tumor was a phyllodes tumor. This scintigraphic finding was thought to be rare and phyllodes tumor should be included in differential diagnosis when 99mTc-HMDP accumulation in the breast was recognized.

Breast Neoplasms↗
PubMed1993

Protective activity of anti-exotoxin A monoclonal antibody against mice infected with toxin-producing Pseudomonas aeruginosa.

The neutralizing and protective effect of murine monoclonal antibody (MAb) 3C7 (IgG1) against Pseudomonas aeruginosa exotoxin A was examined in an experimental mouse model of infection with exotoxin A-producing strains. Treatment with MAb 3C7 blocked the reduction of functional elongation factor 2 (EF-2) in the liver of mice but could not clear the bacteria. Administration of gentamicin caused bacteria to be cleared but did not block reduction of hepatic EF-2 level. Treatment with either MAb 3C7 or gentamicin individually did not prolong time to death; however, the combined therapy with both MAb 3C7 and gentamicin cleared bacteria and blocked the reduction of hepatic EF-2 level, resulting in a significant increase in the survival rate of mice. These results suggest that anti-exotoxin A MAbs show effectiveness against pseudomonal infection caused by exotoxin A-producing strains.

ADP Ribose Transferases↗
PubMed1993

Photocytotoxicity of water-soluble metalloporphyrin derivatives.

A new water-soluble porphyrin derivative, 2,4-bis(1-decyloxyethyl)-deuteroporphyrinyl-6,7-bisaspart ic acid (C10-DP), and its metal complexes (Ga, I(n), Zn, Mn, Cu, Ni and Fe) were examined for their physicochemical properties (absorption, fluorescence, triplet lifetime and partition coefficient) and photocytotoxicity on HeLa cells. The five derivatives with longer (> 1 ms) triplet lifetimes (free base, Zn, Ga, I(n) and Sn complexes) exhibited remarkable photocytotoxicity, and the other derivatives (Mn, Cu, Ni and Fe), which had or were deduced to have fairly short (< 0.01 ms) triplet lifetimes, manifested no photocytotoxicity, indicating that the triplet lifetime of these derivatives played a significant role in their photocytotoxicity. Cellular fluorescence due to C10-DP and its gallium complex was observed mainly on the plasma membrane at the concentrations showing significant photocytotoxicity with low (< 32.6%) cytotoxicity in the dark (2-10 microM).

Aspartic Acid↗
PubMed1993

A yeast mitogen-activated protein kinase homolog (Mpk1p) mediates signalling by protein kinase C.

Mitogen-activated protein (MAP) kinases are activated in response to a variety of stimuli through a protein kinase cascade that results in their phosphorylation on tyrosine and threonine residues. The molecular nature of this cascade is just beginning to emerge. Here we report the isolation of a Saccharomyces cerevisiae gene encoding a functional analog of mammalian MAP kinases, designated MPK1 (for MAP kinase). The MPK1 gene was isolated as a dosage-dependent suppressor of the cell lysis defect associated with deletion of the BCK1 gene. The BCK1 gene is also predicted to encode a protein kinase which has been proposed to function downstream of the protein kinase C isozyme encoded by PKC1. The MPK1 gene possesses a 1.5-kb uninterrupted open reading frame predicted to encode a 53-kDa protein. The predicted Mpk1 protein (Mpk1p) shares 48 to 50% sequence identity with Xenopus MAP kinase and with the yeast mating pheromone response pathway components, Fus3p and Kss1p. Deletion of MPK1 resulted in a temperature-dependent cell lysis defect that was virtually indistinguishable from that resulting from deletion of BCK1, suggesting that the protein kinases encoded by these genes function in a common pathway. Expression of Xenopus MAP kinase suppressed the defect associated with loss of MPK1 but not the mating-related defects associated with loss of FUS3 or KSS1, indicating functional conservation between the former two protein kinases. Mutation of the presumptive phosphorylated tyrosine and threonine residues of Mpk1p individually to phenylalanine and alanine, respectively, severely impaired Mpk1p function. Additional epistasis experiments, and the overall architectural similarity between the PKC1-mediated pathway and the pheromone response pathway, suggest that Pkc1p regulates a protein kinase cascade in which Bck1p activates a pair of protein kinases, designated Mkk1p and Mkk2p (for MAP kinase-kinase), which in turn activate Mpk1p.

Amino Acid Sequence↗
PubMed1993

MKK1 and MKK2, which encode Saccharomyces cerevisiae mitogen-activated protein kinase-kinase homologs, function in the pathway mediated by protein kinase C.

The PKC1 gene of Saccharomyces cerevisiae encodes a homolog of mammalian protein kinase C that is required for normal growth and division of yeast cells. We report here the isolation of the yeast MKK1 and MKK2 (for mitogen-activated protein [MAP] kinase-kinase) genes which, when overexpressed, suppress the cell lysis defect of a temperature-sensitive pkc1 mutant. The MKK genes encode protein kinases most similar to the STE7 product of S. cerevisiae, the byr1 product of Schizosaccharomyces pombe, and vertebrate MAP kinase-kinases. Deletion of either MKK gene alone did not cause any apparent phenotypic defects, but deletion of both MKK1 and MKK2 resulted in a temperature-sensitive cell lysis defect that was suppressed by osmotic stabilizers. This phenotypic defect is similar to that associated with deletion of the BCK1 gene, which is thought to function in the pathway mediated by PCK1. The BCK1 gene also encodes a predicted protein kinase. Overexpression of MKK1 suppressed the growth defect caused by deletion of BCK1, whereas an activated allele of BCK1 (BCK1-20) did not suppress the defect of the mkk1 mkk2 double disruption. Furthermore, overexpression of MPK1, which encodes a protein kinase closely related to vertebrate MAP kinases, suppressed the defect of the mkk1 mkk2 double mutant. These results suggest that MKK1 and MKK2 function in a signal transduction pathway involving the protein kinases encoded by PKC1, BCK1, and MPK1. Genetic epistasis experiments indicated that the site of action for MKK1 and MKK2 is between BCK1 and MPK1.

Amino Acid Sequence↗
PubMed1993

NPK1, a tobacco gene that encodes a protein with a domain homologous to yeast BCK1, STE11, and Byr2 protein kinases.

We have isolated a cDNA (cNPK1) that encodes a predicted protein kinase of 690 amino acids from suspension cultures of tobacco cells. The deduced sequence is closely related to those of the protein kinases encoded by the STE11 and BCK1 genes of Saccharomyces cerevisiae and the byr2 gene of Schizosaccharomyces pombe. STE11 and Byr2 function in the yeast mating pheromone response pathways, and BCK1 acts downstream of the yeast protein kinase C homolog encoded by the PKC1 gene, which is essential for normal growth and division of yeast cells. Overexpression in yeast cells of a truncated form of cNPK1, which encodes only the putative catalytic domain, replaced the growth control functions of BCK1 and PKC1 but not the mating pheromone response function of STE11. Thus, the catalytic domain of NPK1 specifically activates the signal transduction pathway mediated by BCK1 in yeast. In tobacco cells in suspension culture, the NPK1 gene is transcribed during logarithmic phase and early stationary phase but not during late stationary phase. In a tobacco plant, it is also transcribed in stems and roots but not in mature leaves, which rarely contain growing cells. The present results suggest that a signal transduction pathway mediated by this BCK1- and STE11-related protein kinase is also conserved in plants and that a function of NPK1 is controlled at least in part at a transcriptional level.

Amino Acid Sequence↗
PubMed1993

The J-curve phenomenon in stroke recurrence.

BACKGROUND AND PURPOSE: The relation of poststroke blood pressure to stroke recurrence remains undetermined, and the optimal control of blood pressure has not been established. We performed the present study to resolve these issues. METHODS: We analyzed 368 stroke patients with a history of hypertension (mean age, 62 years) who were admitted within 3 months after stroke onset and observed for 6 months or more. We determined stroke recurrence rate in relation to baseline (or initial) blood pressure, mean values of poststroke blood pressure, stroke subtypes, age, antihypertensive treatment, and other clinical features. RESULTS: The recurrence rate had a J-curve relation to poststroke diastolic blood pressure but not to poststroke systolic blood pressure and baseline diastolic and systolic blood pressures. The stroke recurrence rate was 3.8% per patient-year in 94 patients who had a poststroke diastolic blood pressure of 80 to 84 mm Hg, significantly lower than the rates of 9.2% per patient-year (P < .05) and 11.4% per patient-year (P < .01) in those with a lower and higher poststroke diastolic blood pressure, respectively. The range of poststroke diastolic blood pressure accompanying the lowest stroke recurrence rate was higher in patients with atherothrombotic (85 to 89 mm Hg) than in those with lacunar infarction (80 to 84 mm Hg). Neither antihypertensive therapy nor patients' age affected this phenomenon. CONCLUSIONS: The present study suggests that lower blood pressure does not always result in favorable effects on stroke recurrence. The effects of poststroke blood pressure and antihypertensive therapy on stroke recurrence may be complicated by the J-curve phenomenon.

Aged↗
PubMed1993

[Combination therapy of high dose doxifluridine (5'-DFUR)+mitomycin C (MMC) for advanced or recurrent colorectal cancer. Joint Research Group in the Osaka Area for Combination Therapy of 5'-DFUR with Other Drugs].

A co-study was conducted on treatment with high dose 5'DFUR+MMC in order to determine its effectiveness as a systemic chemotherapy in patients with advanced and recurrent colorectal cancers. The treatment schedule included 5'-DFUR given orally at a dose of 1,600 mg/body/day for five consecutive days, a two-day discontinuation, then repeated medication with the above, and MMC injected intravenously at a dose of 6 mg/m2 once every four weeks. One course consisted of four weeks, and courses were repeated as long as tolerated by the patients. Twenty-nine patients were registered for the study and 28 cases were perfectly capable of anti-tumor responses. The response rate was 25.5%, including: CR, 2; PR, 5; NC, 11; and PD, 10 cases. Responding cases were found in metastases to the lung, cervical lymph node and abdominal wall. Response rate was especially high in pulmonary metastases at 41.7% (5/12 cases). The slight side effects were mostly gastrointestinal in nature and did not necessitate drug discontinuance. The results suggest that treatment with high dose 5'-DFUR+MMC is useful for advanced and recurrent colorectal cancers, especially those with pulmonary metastases.

Administration, Oral↗
PubMed1992

Developmental changes in the effect of atrial natriuretic peptide on tissue cyclic GMP content and particulate guanylate cyclase activity of aorta, kidney and lung of rats.

To investigate possible developmental changes in the physiological effect of atrial natriuretic peptide (ANP) after birth, we studied the effect of ANP on the slice cGMP content and the particulate guanylate cyclase activity of aorta, kidney and lung in neonate, 2-week-old and adult rats of both sexes. Incubation with human ANP(99-126) (hANP) increased significantly the slice cGMP content of aorta, kidney and lung in three ages of rats. The hANP-stimulated fraction of cGMP contents of kidney decreased, that of lung increased with development, whereas that of aorta showed no significant change. Consistently, the hANP-responsive particulate guanylate cyclase activity decreased in kidney, increased in lung during development, without significant developmental change in aorta. These results indicate a differential change in the effect of hANP on the slice cGMP content among tissues during development. The developmental change in the effect of hANP on slice cGMP content is probably caused by the ontogenetic change in activation of ANP receptor-linked guanylate cyclase.

Aging↗
PubMed1992

New human gene encoding a positive modulator of HIV Tat-mediated transactivation.

The human immunodeficiency virus-1 (HIV-1) protein Tat is a potent activator of virus gene expression. Tat functions through a sequence known as TAR, located immediately downstream of the transcription start site in the long terminal repeat. Several observations suggest that cellular factors cooperate with Tat in the overall transactivating process. We have isolated a human complementary DNA from the new gene MSS1, which may encode such a cellular factor, by transcomplementation of a yeast sgv1- mutant. The MSS1 protein shares 42% sequence identity with the human TBP-1 protein, which binds Tat in vitro and suppresses Tat-mediated transactivation in vivo (ref. 6). We report here that the levels of HIV activation by Tat correlate with endogenous levels of MSS1 messenger RNA. Furthermore, we provide evidence that expression of MSS1 enhances the Tat-mediated transactivation. Our results suggest that MSS1 has a key role in activation of HIV genes regulated by Tat.

ATPases Associated with Diverse Cellular Activitie↗
PubMed1992

Synthesis of omega-(methoxycarbonyl)alkyl and 9-(methoxycarbonyl)-3,6-dioxanonyl glycopyranosides for the preparation of carbohydrate-protein conjugates.

omega-(Methoxycarbonyl)alkyl glycopyranosides of D-mannose having C4, C7, C9, C12, and C15 carbon chains, L-fucose and 2-acetamido-2-deoxy-D-mannose having C7 and C9 carbon chains, D-xylose and 2-acetamido-2-deoxy-L-fucose having a C9 carbon chain, and 9-(methoxycarbonyl)-3,6-dioxanonyl glycopyranosides of D-mannose, 2-acetamido-2-deoxy-D-mannose, and L-fucose were synthesized as intermediates for coupling to human serum albumin in order to examine the effect of chain length and hydrophobicity of the spacer arm on the binding specificity of lectins. 8-(Methoxycarbonyl)octyl glycosides of beta-D-Man-(1----2)-alpha-D-Man, alpha-D-Man-(1----2)-alpha-D-Man, alpha-D-ManNAc-(1----2)-alpha-D-Man, beta-D-GlcNAc-(1----2)-alpha-D-Man, and their 6-O-positional isomers, beta-D-Man-(1----6)-alpha-D-Man, alpha-D-Man-(1----6)-alpha-D-Man, alpha-D-ManNAc-(1----6)-alpha-D-Man, and beta-D-GlcNAc-(1----6)-alpha-D-Man, were also synthesized.

Carbohydrate Sequence↗