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N Tominaga

Publications and source records attributed to N Tominaga.

At least 19 recordsLinked to original sources
PubMed2001

Isolation, growth, ultrastructure, and metal tolerance of the green alga, Chlamydomonas acidophila (Chlorophyta).

An acidophilic volvocine flagellate, Chlamydomonas acidophila (Volvocales) that was isolated from an acid lake, Katanuma, in Miyagi prefecture, Japan was studied for growth, ultrastructural characterization, and metal tolerance. Chlamydomonas acidophila is obligately photoautotrophic, and did not grow in the cultures containing acetate or citrate even in the light. The optimum pH for growth was 3.5-4.5. To characterize metal tolerance, the toxic effects of Cd, Co, Cu, and Zn on this alga were also studied. Effective metal concentrations, which limited the growth by 50%, EC50 were measured, after 72 h of static exposure. EC50s were 14.4 microM Cd2+, 81.3 microM Co2+, 141 microM Cu2+, and 1.16 mM Zn2+ for 72 h of exposure. Thus, this alga had stronger tolerance to these metals than other species in the genus Chlamydomonas.

Adaptation, Physiological↗
PubMed2000

Molecular cloning of ring finger protein 21 (RNF21)/interferon-responsive finger protein (ifp1), which possesses two RING-B box-coiled coil domains in tandem.

We have cloned the full length of a novel cDNA, named ring finger protein 21 (RNF21), composed of the RING finger-B box-coiled coil (RBCC) domain and the B30.2 domain, which are characteristic of the RBCC-B30.2 family. As a structural feature, the RNF21 cDNA possessed at least three kinds of isoforms, due to alternative splicing, consisting of the long form with the RBCC-RBCC-B30.2 domain, the medium form with the RBCC-B30.2 domain, and the short form with only the RBCC domain. Moreover, respective transcripts corresponding to the three isoforms were detected in various human organs by reverse transcription-PCR and Northern blot analyses. Interestingly, the medium form of the RNF21 mRNA expressed most predominantly was dramatically up-regulated within 8-16 h by interferon stimulation of HeLa cells. These findings suggest that RNF21 is a downstream gene that may mediate interferon's biological action.

Alternative Splicing↗
PubMed2000

Molecular cloning of testis-abundant finger Protein/Ring finger protein 23 (RNF23), a novel RING-B box-coiled coil-B30.2 protein on the class I region of the human MHC.

We have identified a genomic DNA fragment, using the PCR method with degenerate oligonucleotide primers which contain the conserved sequence of the RING finger domain. Using the DNA fragment as a probe, a novel cDNA was cloned from human and mouse testis. The cDNA had a domain structure of the typical RING-B box-coiled coil (RBCC)-B30.2 domain and therefore was named testis-abundant finger protein (tfp). Indeed, the transcript was highly expressed in the testis, although it was also found ubiquitously in various organs by Northern blot analysis. The tfp gene was mapped at the class I region of the human MHC (major histocompatibility complex), within which some known RBCC-B30.2 proteins such as RFP, RFB30/HERF1, AFP, and HZF had been localized. These findings demonstrate that several RBCC-B30.2 proteins including tfp, which are non-HLA proteins, are clustered within the class I region of the human MHC.

Amino Acid Sequence↗
PubMed1999

Underdeveloped uterus and reduced estrogen responsiveness in mice with disruption of the estrogen-responsive finger protein gene, which is a direct target of estrogen receptor alpha.

The biological roles of estrogen-responsive finger protein (efp) in vivo were evaluated in mice carrying a loss-of-function mutation in efp by gene-targeted mutagenesis. Although efp homozygous mice were viable and fertile in both sexes, the uterus that expressed abundant estrogen receptor alpha exhibited significant underdevelopment. When the ovariectomized homozygotes were subjected to 17beta-estradiol treatment, they showed remarkably attenuated responses to estrogen, as exemplified by decreased interstitial water imbibition and retarded endometrial cell increase, at least, attributable to the lower ratio of G1 to S-phase progression in epithelial cells. These results suggest that efp is essential for the normal estrogen-induced cell proliferation and uterine swelling as one of the direct targets of estrogen receptor alpha.

Animals↗
PubMed1999

Takayasu's aortitis with dissection in systemic lupus erythematosus.

A forty-seven-year-old Japanese woman under treatment for systemic lupus erythematosus (SLE), complained of severe back pain. Chest X-ray and MRI showed an aneurysmal dilatation of the ascending aorta. Subsequently an aortic replacement was performed. Microscopically, the resected aorta showed Takayasu's aortitis with chronic dissection. Both aortitis and dissection are rare events in SLE patients. To our knowledge, this is the first report of Takayasu's aortitis with dissection in a patient with SLE.

Aortic Dissection↗
PubMed1998

Molecular cloning, localization, and developmental expression of mouse brain finger protein (Bfp)/ZNF179: distribution of bfp mRNA partially coincides with the affected areas of Smith-Magenis syndrome.

Bfp (brain finger protein) is a member of the RING finger protein family, which is highly expressed in the brain. We have previously shown that one copy of the human bfp gene, mapped at 17p11.2, was actually deleted in six of six Smith-Magenis syndrome (SMS) patients. Now we have isolated the mouse bfp cDNA. Using in situ hybridization and immunohistochemistry, the distribution of mouse bfp mRNA and protein was identified especially in neural cells of the cerebral cortex, hippocampus, lateral amygdaloid nucleus, and ventromedial hypothalamus. In primary culture of the whole brain in a neonatal mouse, the Bfp protein was detected in both neuron and glial cells, and its subcellular localization was predominantly in the nucleus, but some amounts were also found in the cytoplasm. The bfp mRNA was also expressed strongly in the marginal zone of brain vesicles, optic stalk, and cartilage primordium, which are part of the critical tissues frequently involved in SMS patients, and in such tissues as nasal epithelium and primordium of follicles in a 13. 5-dpc embryo. Subsequently, its amount in the developing brain further increased during embryogenesis, reaching the highest level in the adult brain. These findings suggest a possibility that Bfp might be involved in the pathogenesis of Smith-Magenis syndrome as a regulator protein related to neural differentiation and function.

Abnormalities, Multiple↗
PubMed1997

Effect of replacement of the amino and the carboxyl termini of rat testis fructose 6-phosphate, 2-kinase:fructose 2,6-bisphosphatase with those of the liver and heart isozymes.

Fru 6-P,2-kinase:Fru 2,6-Pase is a bifunctional enzyme, consisting of highly conserved catalytic domains and variable regulatory domains. The regulatory domains reside in either the N- or the C-terminus, depending upon the isozyme. The rat testis enzyme (RT2K) lacks the regulatory domain, but the rat liver and the bovine heart enzymes contain phosphorylation site(s) in the N- and the C-termini, respectively. In order to determine whether the regulatory domains can be swapped, we have constructed mutant enzymes in which the N- or the C-terminal tail of the testis enzyme was replaced with that of either the liver or the heart enzyme. The substitution with the N-terminus of the liver enzyme (RLN-RT2K) resulted in a small change in the kinetic properties of Fru 6-P,2-kinase, but that with the heart enzyme increased the KFru 6-P 18-fold without affecting the Vmax. The substitution with the C-terminus of the heart enzyme had little effect. The phosphorylation of RLN-RT2K increased KFru 6-P fivefold as in the liver enzyme but did not affect the Fru 2,6-Pase, unlike the liver enzyme. All these mutant enzymes were more thermally labile than the wild type testis enzyme. RLN-RT2K was more sensitive to the denaturant. These results suggest that the N-terminus of the liver enzyme could interact with the kinase domain of the testis enzyme, regulating the kinase activity but was unable to affect the phosphatase domain. These differences could be explained by the large differences in net charges of the terminal tails.

Allosteric Regulation↗
PubMed1997

Inhibition of fructose-6-phosphate,2-kinase by N-bromoacetylethanolamine phosphate in vitro and in vivo.

Fructose-6-phosphate,2-kinase/fructose-2,6-bisphosphatase (Fru-6-P,2-kinase/Fru-2,6-BPase), a bifunctional enzyme, catalyzes the synthesis and degradation of a potent activator, fructose-2,6-bisphosphate (Fru-2,6-P2), of phosphofructokinase, and has been postulated to be an important enzyme in the regulation of glycolysis in mammalian tissues. The purpose of this study was to determine whether or not N-bromoacetylethanolamine phosphate (BrAcNHEtOP), a specific active site-directed inactivator of Fru-6-P,2-kinase, is useful for studies on the role of Fru-6-P,2-kinase in the regulation of glycolysis in vivo. BrAcNHEtOP inactivated purified recombinant rat testis-type Fru-6-P,2-kinase as well as Fru-6-P,2-kinase in a rat liver extract, with half maximum inactivation concentrations of 2 and 15 mM, respectively, on 30 min incubation at 30 degrees C. The increases in Fru-6-P,2-kinase activity and the Fru-2,6-P2 concentration in livers, prepared from fasted rats, induced by high glucose (50 mM) perfusion were suppressed in parallel after pre-perfusion with 1 to 10 mM BrAcNHEtOP, dose-dependently. Five hours after intraperitoneal injection of BrAcNHEtOP (50 to 150 mg/kg) into mice, the Fru-6-P,2-kinase activity and Fru-2,6-P2 concentration in livers had decreased in parallel, dose-dependently. These effects continued for 24 h and were accompanied by decreases in the fructose-1,6-bisphosphate, triose phosphates, and lactate contents, although the contents of glucose-6-phosphate and fructose-6-phosphate did not change. These results suggested that BrAcNHEtOP inactivates Fru-6-P, 2-kinase, resulting in a decrease in the Fru-2,6-P2 level, which causes inactivation of phosphofructokinase and consequently inhibition of glycolysis in liver. Furthermore, the suppressed levels of Fru-6-P,2-kinase activity and metabolites in mice livers were sustained by daily injection of BrAcNHEtOP for 4 days, and body weight gain was also suppressed during the administration of BrAcNHEtOP. These results suggested that BrAcNHEtOP will be a useful reagent for studying the role of Fru-6-P,2-kinase in vivo.

Animals↗
PubMed1997

Characterization of a human placental fructose-6-phosphate, 2-kinase/fructose-2,6-bisphosphatase.

A full-length cDNA, which encodes a human placental fructose-6-phosphate,2-kinase/ fructose-2,6-bisphosphatase, was constructed and expressed in Escherichia coli. The expressed protein, purified to homogeneity, showed a molecular weight of 58,000 by gel electrophoresis under denaturing conditions, compared to the deduced molecular weight of 59,410. The N-terminal sequence of 15 amino acids coincided with that of the deduced sequence. The active enzyme was a dimer as judged by molecular sieve filtration. The expressed enzyme was bifunctional with Vmax values of 142 and 0.2 milliunits/mg for the kinase and phosphatase activities, respectively. The phosphatase activity was extremely low, because one phosphatase active site residue was mutated, and consequently the kinase/phosphatase ratio was the highest among the known isozymes. Furthermore, the enzyme was phosphorylated by cAMP-dependent protein kinase, protein kinase C and also by [2-32P]fructose-2,6-bisphosphate. Phosphorylation by cAMP-dependent protein kinase and protein kinase C increased the maximal Fru-6-P,2-kinase activities by 1.8- and 1.1-fold, respectively. These results suggested that placental fructose-6-phosphate,2-kinase/ fructose-2,6-bisphosphatase is important in maintaining and regulating a relatively high rate of glycolysis in placenta.

Cyclic AMP-Dependent Protein Kinases↗
PubMed1996

Insufficient calcium and iron intakes among general female population in Japan, with special reference to inter-regional differences.

Dietary intakes of calcium (Ca) and iron (Fe) were investigated in 227 women (mostly housewives) in 12 regions in Japan in 1991-1993 by the 24-hour food duplicate method. Nine regions out of 12 had been previously studied in 1977-1982. Utilizing Standard Food Composition database, mean Ca and Fe-intakes in 1991-1993 were estimated to be 602 and 10.4 mg/day, respectively; the former was barely sufficient and the latter was below sufficiency when compared with the Recommended Daily Allowance in Japan for pre-menopausal women. Ca- and Fe-intake did not increase in the 10-year period. Further analysis after classification of the women into three groups of farmers in Okinawa, farmers in Mainland Japan and urban residents showed that Ca and Fe insufficiency was most evident among Okinawa farmers. The leading Ca sources were milk, pulse, vegetables and fish-shellfish, but consumption of milk was generally low, especially among Okinawa farmers. Pulse, vegetables and fish-shellfish were 3 major Fe sources; Okinawa farmers depended more on vegetables and less on fish-shellfish.

Calcium↗
PubMed1994

Reversible unfolding of fructose 6-phosphate, 2-kinase:fructose 2,6-bisphosphatase.

Reversible unfolding of rat testis fructose 6-phosphate,2-kinase:fructose 2,6-bisphosphatase in guanidine hydrochloride was monitored by following enzyme activities as well as by fluorescence methodologies (intensity, emission maximum, polarization, and quenching), using both intrinsic (tryptophan) and extrinsic (5((2-(iodoacetyl)amino) ethyl)naphthalene-1-sulfonic acid) probes. The unfolding reaction is described minimally as a 4-state transition from folded dimer-->partially unfolded dimer-->monomer-->unfolded monomer. The partially unfolded dimer had a high phosphatase/kinase ratio due to preferential unfolding of the kinase domain. The renaturation reaction proceeded by very rapid conversion (less than 1 s) of unfolded monomer to dimer, devoid of any enzyme activity, followed by slow (over 60 min) formation of the active enzyme. The recovery rates of the kinase and the phosphatase were similar. Thus, the refolding appeared to be a reversal of the unfolding pathway involving different forms of the transient dimeric intermediates. Fluorescence quenching studies using iodide and acrylamide showed that the tryptophans, including Trp-15 in the N-terminal peptide, were only slightly accessible to iodide but were much more accessible to acrylamide. Fructose 6-phosphate, but not ATP or fructose 2,6-bisphosphate, diminished the iodide quenching, but all these ligands inhibited the acrylamide quenching by 25%. These results suggested that the N-terminal peptide (containing a tryptophan) was not exposed on the protein surface and may play an important role in shielding other tryptophans from solvent.

Acrylamides↗
PubMed1994

Marked increase of CD8+S6F1+ and CD8+CD57+ cells in patients with graft-versus-host disease after allogeneic bone marrow transplantation.

Peripheral blood lymphocytes (PBL) from 24 allogeneic bone marrow transplant (BMT) recipients were studied serially using flow cytometry and two-color analysis. Dual labelling with two monoclonal antibodies (moAbs), CD8/S6F1 (CD11a) and CD8/CD57 was used to analyze the surface phenotypes of PBL after allogeneic BMT. In patients with acute and chronic GVHD, CD8+S6F1+ cells were markedly increased from the onset of GVHD and recovered to normal range 6 years after transplantation. By contrast, CD8+S6F1- cells fell below normal range and remained markedly decreased for 2-3 years after transplantation in patients with acute and chronic GVHD. A slight but significant increase of CD8+CD57- cells was observed with clinical signs of acute GVHD. On the other hand, CD8+CD57+ cells were increased after the onset of acute and chronic GVHD and recovered to normal range 6 years after transplantation. These results suggest that these subsets of CD8+ cells may play important roles in the pathophysiology of GVHD.

Adolescent↗
PubMed1994

[The monitoring of cytomegalovirus antigenemia and arterial oxygen saturation for the early detection of cytomegalovirus pneumonia].

Eighteen patients underwent allogeneic bone marrow transplantation (allo. BMT) during the period May, 1991 to December, 1992 in the Center for Adult Diseases, Osaka. They were monitored for cytomegalovirus (CMV) antigenemia and arterial oxygen saturation (SaO2). More than 10 antigen-positive cells per 50,000 polymorphonuclear leukocytes were detected in five of 18 patients. Three of these 5 patients developed CMV pneumonia several weeks after the first detection of more than 10 positive cells. Six of 18 patients developed interstitial pneumonia (IP) (3 CMV pneumonia and 3 idiopathic IP). SaO2 decreased less than 95% several days before the development of IP in 3 of these 6 patients (2 of CMV pneumonia and 1 of idiopathic IP). CMV antigenemia assay and SaO2 assay were thus both considered to be useful for the early detection or prediction of development of CMV pneumonia.

Adolescent↗
PubMed1993

Significance of the amino terminus of rat testis fructose-6-phosphate, 2-kinase:fructose-2,6-bisphosphatase.

In order to assess the functional properties of the extreme amino-terminal peptide of rat testis fructose-6-phosphate,2-kinase: fructose-2,6-bisphosphatase, 24 and 30 amino acids from the NH2 terminus were deleted using oligonucleotide-directed mutagenesis. The expressed wild-type (WT) and the mutant (Del 24 and Del 30) enzymes were purified to homogeneity. These enzymes were homodimers of subunit M(r) values 54,000, 51,300, and 50,600. Deletion of 1-24 and 1-30 residues resulted in over 70% loss of Fru-6-P,2-kinase activity and 2-fold increase in Fru-2,6-bisphosphatase. KmFru-6-P increased 7.5-fold, but there was no significant change in KmFru-2,6P2 of the phosphatase. These mutant enzymes were more susceptible to protein concentration-dependent dissociation and thermal inactivation. In 2 M urea the kinase and the phosphatase activities of WT increased 17 and 56%, respectively, but no activation of any of the mutant enzymes was observed. At higher urea concentrations, all the enzymes were inactivated. Unfolding in urea, followed with intrinsic tryptophan fluorescence, showed that the unfolding proceeded in at least two stages. Fluorescence intensity at 338 nm of all these enzymes decreased below 2 M urea in which the enzyme activities remained the same (Del 24) or activated (WT). The second stage of unfolding was seen as the maximum shifted to 342 nm in 2-4 M urea, presumably involving dissociation. Complete unfolding above 4 M urea resulted in further shift in fluorescence maximum to 350 nm.

Amino Acid Sequence↗
PubMed1993

Varicella-zoster virus infection in immunocompromised patients.

The prophylactic effect of acyclovir (ACV) on varicella-zoster virus (VZV) infection in leukaemia patients who have undergone bone marrow transplantation (BMT) was reviewed. The benefits of the use of the laminar air flow (LAF) room in the prevention of nosocomial VZV infections in the haematological ward are also discussed. Since 1986 ACV has been administered to BMT patients to prevent herpes simplex virus (HSV) infections. Of 98 patients with leukaemia who underwent BMT, 73 received ACV (200 mg five times daily) and 25 were not given ACV. In the untreated group, 9 patients (36.0%) developed VZV infection by day 67 (median) and 3 patients died due to disseminated VZV infection. In the ACV-treated group, 18 patients (24.6%) developed VZV infection by day 150 (median) and there were no deaths. From July to December 1989, nine cases of VZV infections (eight patients and one nurse) were reported in the haematological ward of the hospital. All cases originated in the conventionally ventilated areas of the ward while no VZV infections were reported in the 14 patients who occupied the LAF rooms during the same period.

Acyclovir↗
PubMed1993

Progressive renal failure in patients with lupus nephritis.

OBJECTIVE: To investigate the mode of progression to renal failure in patients with lupus nephritis in relation to disease activity and responsiveness to corticosteroid therapy. DESIGN: Retrospective clinical study. SETTING: University hospital. SUBJECTS: Twenty-eight patients with progressive lupus nephritis (Cr > or = 1.4 mg dl-1). INTERVENTIONS: Rapidity of progression was defined as the slope of the reciprocal of serum creatinine values. Lupus activity was scored using the systemic lupus erythematosus disease activity index system. MAIN OUTCOME MEASURES: Improvement of serum creatinine values after 6 months of therapy. RESULTS: Rapidity of progression, which was calculated during the deterioration in kidney function, reflected systemic and serological disease activity, and moreover closely correlated with response to corticosteroid therapy.

Creatinine↗