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Biomedical subjects

T Ito

Publications and source records attributed to T Ito.

At least 145 records · Page 8Linked to original sources
PubMed2001

Types of lumbar herniated disc and clinical course.

STUDY DESIGN: A retrospective study of different types of herniated discs and duration of symptoms in patients with lumbar disc herniation, and a trial of longer conservative treatment to reduce the number of operations. OBJECTIVE: To determine whether noncontained and contained herniated discs have different clinical courses and to evaluate the results of the clinical trial of longer and vigorous conservative treatment. SUMMARY OF BACKGROUND DATA: The possibility of a difference in clinical features between contained and noncontained disc herniation has been suggested previously. METHODS: In the first study, the medical history and intraoperative findings of 156 patients who had undergone herniotomy were reviewed. In the second study, conservative treatment of at least 2 months' duration was recommended for all patients with lumbar disc herniation. RESULTS: In the first study, patients with noncontained disc herniation had a shorter preoperative clinical course than those with contained disc herniation. It was rare for noncontained herniation to require surgery 4 months or more after the onset of symptoms. In the second study, the authors' protocol reduced the number of herniotomies required, especially the number of operations for the patients with noncontained disc herniation. CONCLUSIONS: The authors believe that patients with noncontained lumbar disc herniation can be treated without surgery, if these patients can tolerate the symptoms for the first 2 months.

Adolescent↗
PubMed2001

A comprehensive two-hybrid analysis to explore the yeast protein interactome.

Protein-protein interactions play crucial roles in the execution of various biological functions. Accordingly, their comprehensive description would contribute considerably to the functional interpretation of fully sequenced genomes, which are flooded with novel genes of unpredictable functions. We previously developed a system to examine two-hybrid interactions in all possible combinations between the approximately 6,000 proteins of the budding yeast Saccharomyces cerevisiae. Here we have completed the comprehensive analysis using this system to identify 4,549 two-hybrid interactions among 3,278 proteins. Unexpectedly, these data do not largely overlap with those obtained by the other project [Uetz, P., et al. (2000) Nature (London) 403, 623-627] and hence have substantially expanded our knowledge on the protein interaction space or interactome of the yeast. Cumulative connection of these binary interactions generates a single huge network linking the vast majority of the proteins. Bioinformatics-aided selection of biologically relevant interactions highlights various intriguing subnetworks. They include, for instance, the one that had successfully foreseen the involvement of a novel protein in spindle pole body function as well as the one that may uncover a hitherto unidentified multiprotein complex potentially participating in the process of vesicular transport. Our data would thus significantly expand and improve the protein interaction map for the exploration of genome functions that eventually leads to thorough understanding of the cell as a molecular system.

Fungal Proteins↗
PubMed2001

Application of a new analytical method using gas chromatography and gas chromatography-mass spectrometry for the azide ion to human blood and urine samples of an actual case.

We have established a practical and reliable method to identify and quantify the azide ion in human whole blood and human urine by transforming the ion into pentafluorobenzyl azide (PFBN3). PFBN3 was simply derived from a reaction of the ion with an excess amount of pentafluorobenzyl bromide (PFBBr). The excess amount of PFBBr was removed from the products by its reaction with sodium thiosulfate. PFBN3 in the sample was detected in high sensitivity by gas chromatography with nitrogen-phosphorus detector (GC-NPD) and gas chromatography-mass spectrometry (GC-MS). The lower detection limits of the ion by GC-NPD were 5 ng/ml for human whole blood sample and 0.5 ng/ml for human urine sample at S/N=3. On the other hand, they were 100 ng/ml for human whole blood sample and 10 ng/ml for human urine sample by the full-scan mode of GC-MS. The analytical method was applied to identification and quantification of the ion in the actual whole blood and urine samples of the victims in an actual criminal case.

Azides↗
PubMed2001

Scanning tunneling microscopy with chemically modified tips: discrimination of porphyrin centers based on metal coordination and hydrogen bond interactions.

STM gold tips chemically modified with 4-mercaptopyridine (4MP) were found capable of discriminating zinc(II) 5,15-bis(4-octadecyloxyphenyl)porphyrin (Por-Zn) from its metal-free porphyrin (Por-2H) and nickel(II) complexes (Por-Ni) in the mixed monolayers of these compounds, spontaneously formed at the solution/graphite interface. The porphyrin centers in STM images observed with 4MP-modified tips exhibited bright spots, while those measured with unmodified tips exhibited the porphyrin centers as dark depressions. The centers of Por-Zn were brighter than those of Por-2H and Por-Ni, thereby allowing the discrimination of Por-Zn from Por-2H or Por-Ni in mixed monolayers. The changes in the contrasts of porphyrin centers of Por-2H and Por-Zn/ Por-Ni were explained by facilitated electron tunneling due to hydrogen bond and metal coordination interactions, respectively, between porphyrin centers and the pyridyl group of 4MP on the tip.

Hydrogen Bonding↗
PubMed2001

Differential regulation of human blood dendritic cell subsets by IFNs.

Based on the relative expression of CD11c and CD1a, we previously identified subsets of dendritic cells (DCs) or DC precursors in human peripheral blood. A CD1a(+)/CD11c(+) population (CD11c(+) DCs), also called myeloid DCs, is an immediate precursor of Langerhans cells, whereas a CD1a(-)/CD11c(-) population (CD11c(-) DCs), sometimes called lymphoid DCs but better known as plasmacytoid DCs, is composed of type I IFN (IFN-alpha beta)-producing cells. Here, we investigate the effects of IFN-alpha beta and IFN-gamma as well as other cytokines on CD11c(+) and CD11c(-) DC subsets, directly isolated from the peripheral blood, instead of in vitro-generated DCs. IFN-gamma and IFN-alpha, rather than GM-CSF, were the most potent cytokines for enhancing the maturation of CD11c(+) DCs. Incubation of CD11c(+) DCs with IFN-gamma also resulted in increased IL-12 production, and this IL-12 allowed DCs to increase Th1 responses by alloreactive T cells. In contrast, IFN-alpha did not induce IL-12 but, rather, augmented IL-10 production. IFN-alpha-primed matured CD11c(+) DCs induced IL-10-producing regulatory T cells; however, this process was independent of the DC-derived IL-10. On the other hand, IFN-alpha by itself neither matured CD11c(-) DCs nor altered the polarization of responding T cells, although this cytokine was a potent survival factor for CD11c(-) DCs. Unlike IFN-alpha, IL-3 was a potent survival factor and induced the maturation of CD11c(-) DCs. The IL-3-primed CD11c(-) DCs activated T cells to produce IL-10, IFN-gamma, and IL-4. Thus, CD11c(+) and CD11c(-) DC subsets play distinct roles in the cytokine network, especially their responses to IFNs.

Cell Differentiation↗
PubMed2001

Budding yeast GCN1 binds the GI domain to activate the eIF2alpha kinase GCN2.

When starved for a single amino acid, the budding yeast Saccharomyces cerevisiae activates the eukaryotic initiation factor 2alpha (eIF2alpha) kinase GCN2 in a GCN1-dependent manner. Phosphorylated eIF2alpha inhibits general translation but selectively derepresses the synthesis of the transcription factor GCN4, which leads to coordinated induction of genes involved in biosynthesis of various amino acids, a phenomenon called general control response. We recently demonstrated that this response requires binding of GCN1 to the GI domain occurring at the N terminus of GCN2 (Kubota, H., Sakaki, Y., and Ito, T. (2000) J. Biol. Chem. 275, 20243-20246). Here we provide the first evidence for the involvement of GCN1-GCN2 interaction in activation of GCN2 per se. We identified a C-terminal segment of GCN1 sufficient to bind the GI domain and used a novel dual bait two-hybrid method to identify mutations rendering GCN1 incapable of interacting with GCN2. The yeast bearing such an allele, gcn1-F2291L, fails to display derepression of GCN4 translation and hence general control response, as does a GI domain mutant, gcn2-Y74A, defective in association with GCN1. Furthermore, we demonstrated that phosphorylation of eIF2alpha is impaired in both mutants. Since GCN2 is the sole eIF2alpha kinase in yeast, these findings indicate a critical role of GCN1-GCN2 interaction in activation of the kinase in vivo.

Amino Acid Sequence↗
PubMed2001

Measurement of the gain volume in amplifying and scattering media by a two-beam spatial-correlation method.

We measured the size of the gain volume at the threshold of the spectral collapse in a solution of kiton red with colloidal suspensions of polystyrene spheres using a two-beam spatial-correlation method. In this method, the luminescence spectrum was measured as a function of the spatial separation of two excitation beams. It was found that the size of the gain volume at the threshold L(th), is proportional to the absorption length L(a), for different samples. Numerical simulations are also presented and the results are discussed on the basis of a relation L(th)=sqrt[3G(th)]sqrt[sigma(a)/sigma(s)]L(a), where sigma(s) and sigma(a) are stimulated emission and absorption cross sections of kiton red, respectively.

Journal Article↗
PubMed2001

Cross-coupling reactions of potassium alkyltrifluoroborates with aryl and 1-alkenyl trifluoromethanesulfonates.

[figure: see text] The palladium-catalyzed coupling reaction of potassium alkyltrifluoroborates with aryl- or alkenyltriflates proceeds to afford the corresponding arenes or alkenes in high yield. The borates are all solids, stable in air, and thus can be stored on the shelf indefinitely. The cross coupling can be effected using PdCl2(dppf).CH2Cl2 as the catalyst in THF-H2O in the presence of Cs2CO3. A variety of functional groups can be tolerated within the borate and/or the triflate coupling partner.

Alkenes↗
PubMed2001

The direct effect of IL-12 on tumor cells: IL-12 acts directly on tumor cells to activate NF-kappaB and enhance IFN-gamma-mediated STAT1 phosphorylation.

IL-12 directly acts on T cells and NK cells to induce IFN-gamma production. IFN-gamma plays an important role in anti-tumor effect of IL-12. In spite of various functions of IL-12 on immunocytes, the direct effect of IL-12 on tumor cells has not been fully clarified. The present study investigated the direct effect of IL-12 on eight murine tumor cell lines in vitro. IL-12 did not directly up-regulate expression of MHC class I on tumor cells, but enhanced IFN-gamma-induced up-regulation of MHC class I expression in MC-38, MCA102, MCA205 and MCA207 cells. IL-12 alone did not activate STAT1, but IL-12 enhanced IFN-gamma-mediated STAT1 phosphorylation in MC-38, MCA102, MCA205, MCA207 and Colon-26-NL-17 cells, which expressed IL-12 receptor beta1 mRNA. In the other side, Panc-02, B16-BL6 and 266-6 cells were not affected by IL-12, in which expression of IL-12 receptor beta1 mRNA was not detected. Anti-IL-12 mAb inhibited the direct effect of IL-12 on MC-38 cells. Moreover, nuclear localization of NF-kappaB was observed after stimulation of IL-12 or IL-12 p40 in MC-38 and Colon-26-NL-17 cells, but not in Panc-02 cells. These findings suggest that IL-12 directly acts on tumor cells through IL-12 receptor beta1 to activate NF-kappaB and enhance IFN-gamma-mediated STAT1 phosphorylation.

Active Transport, Cell Nucleus↗
PubMed2001

Aldosterone production is activated in failing ventricle in humans.

BACKGROUND: Recent reports have indicated that aldosterone is produced in extra-adrenal tissues in animals. The present study was designed to examine whether aldosterone is produced in human heart. METHODS AND RESULTS: Plasma levels of aldosterone, BNP, and angiotensin-converting enzyme were measured in anterior interventricular vein (AIV), coronary sinus (CS), and aortic root (Ao), respectively, in 20 patients with left ventricular systolic dysfunction (LVSD), 25 patients with LV diastolic dysfunction (LVDD), and 23 control subjects. Aldosterone levels were significantly higher in AIV and CS than Ao in LVSD (98+/-10 versus 72+/-9 pg/mL, P:<0.001, and 97+/-11 versus 72+/-9 pg/mL, P:<0.001, respectively) and LVDD (87+/-10 versus 71+/-9 pg/mL, P:<0.01, and 84+/-10 versus 71+/-9 pg/mL, P:<0.01, respectively) groups, but no differences were observed in levels for these sites in the control group. Levels of ACE activity and BNP also were higher in AIV than Ao in both LV dysfunction groups. The difference in aldosterone levels between AIV and Ao and those in BNP and angiotensin-converting enzyme had a significant positive correlation with LVEDP and a significant negative correlation with LV ejection fraction in the LVSD group. CONCLUSIONS: Production of aldosterone, angiotensin-converting enzyme, and BNP are activated in failing human ventricle in proportion to severity.

Adult↗
PubMed2001

Small molecular mass inhibitor of growth of MDCK cells derived from pig spinal cord.

We have discovered cell growth inhibitory activity in a salt extract of pig spinal cords. The growth inhibitory factor was purified by gel-filtration, ion-exchange and high performance liquid chromatography. Incubation of MDCK cells with the inhibitor arrested their locomotion within half an hour, suppressed their proliferation, and caused them to become round. The round cells that were still attached to the culture plate were alive. Upon removal of the inhibitor these cells flattened out and resumed locomotion and proliferation. The inhibitor was 100 times less effective on CHO-K1 cells. The reversible effects of the inhibitor on MDCK cells and its little effects on CHO-K1 cells indicate that the inhibitory activity is not due to a non-specific toxic mechanism. The inhibitor was both heat-stable and resistant to several chemical treatments, including proteases. Its behavior upon ion exchange chromatography suggested that it was positively charged at neutral pH, whilst its molecular mass was estimated to be 350 or larger by gel-filtration FPLC analysis. The inhibitory fraction reacted extensively with fluorescamine, suggesting that the inhibitory factor has amine groups, which are a possible candidate for its positive charges. Since spermine and spermidine, unlike the inhibitor in the present study, irreversibly inhibited the growth of the MDCK cells, the inhibitory activity in the present study is thus not due to contamination by these polyamines. Our experiments also support that the inhibitor is not a peptide.

Animals↗
PubMed2001

Alteration of peripheral blood dendritic cells in patients with primary Sjögren's syndrome.

OBJECTIVE: We recently identified 3 fractions of human peripheral blood (PB) dendritic cells (DC), including the monocyte-associated fractions 1 and 2 (CD1a+,CD11c+ and CD1a-,CD11c+, respectively) and the lymphoid-associated fraction 3 (CD1a-,CD11c-). We attempted to determine whether these fractions were altered in Sjögren's syndrome (SS). METHODS: We examined 23 patients with primary SS and 22 normal control subjects. DC were purified from PB and analyzed by flow cytometry. Immunohistochemical staining of labial salivary glands of SS patients was performed with monoclonal antibodies against fascin, which is known to be specific for DC. RESULTS: The total numbers of PB DC and fraction 1 DC were decreased in SS. Immunohistochemical staining demonstrated that fascin+,CD11c+,HLA-DR+ mononuclear cells were present and scattered among numerous fascin-hyperfiltrating cells in SS patients. Interferon-gamma (IFNgamma)-producing Th1 cells were shown to be increased in both PB and salivary glands of patients, indicating the presence of general IFNgamma-producing Th1 polarization in SS. Furthermore, numbers of Thl cells were increased when naive T cells were cocultured with fraction 1 DC in vitro. CONCLUSION: These findings suggest selective trafficking of fraction 1 DC into focal sites of inflammation and subsequent promotion of Th1 balance, suggesting a novel pathogenesis of SS.

Adult↗
PubMed2001

Relationships of matrix metalloproteinases and their inhibitors to cartilage proteoglycan and collagen turnover and inflammation as revealed by analyses of synovial fluids from patients with rheumatoid arthritis.

OBJECTIVE: To determine interrelationships in matrix turnover in articular cartilage and joint inflammation in rheumatoid arthritis (RA). METHODS: Synovial fluid was obtained from the knees of 63 RA patients; radiographs were evaluated to determine the RA stage. Concentrations of matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), the 846 epitope, and the keratan sulfate (KS) epitope of aggrecan, the C-propeptide of cartilage type II procollagen (CPII; biosynthetic marker), the cleavage of type II collagen by collagenase (CIIC; generated neoepitope), and polymorphonuclear leukocyte elastase (PMNE; inflammation marker) were measured by immunoassay. Concentrations of the unsaturated disaccharides of hyaluronic acid (delta di-HA) and the proteoglycan glycosaminoglycan disaccharides of chondroitins 4 and 6 sulfate (delta di-C4S and delta di-C6S) were determined by high-performance liquid chromatography. RESULTS: MMP-3 was markedly increased in RA compared with osteoarthritis. Increases in TIMP-1 in RA were less pronounced and were inversely correlated with MMP-3 levels. CIIC was reduced in RA, as was the release of the KS epitope and delta di-C6S. In contrast, delta di-C4S and the 846 epitope were up-regulated. PMNE levels correlated with the 846 epitope and delta di-C4S, and more strongly with TIMPs 1 and 2. The changes may signify attempts at control of proteolysis in parallel with increased aggrecan turnover, which would favor matrix assembly. PMNE also correlated with MMP-9, and MMP-9 correlated with CPII. The delta di-HA level was decreased in RA and was inversely correlated with CPII and MMP-9 as well as with MMPs 2 and 3. In contrast, delta di-HA was directly correlated with TIMP-1 and the 846 epitope. These observations suggest that HA and PMNs may be involved in the control of proteolysis and cartilage proteoglycan assembly. CONCLUSION: Our observations provide new insights into the complex changes in cartilage turnover and PMN influx in RA joints.

Adult↗
PubMed2001

Interleukin-6 and acute coronary syndrome.

The designation of atherosclerosis as a chronic inflammatory process represents an exciting and logical paradigm shift for cardiologists. Plasma concentrations of interleukin-6 (IL-6) and its hepatic by-product C-reactive protein (CRP) appear to reflect the intensity of occult plaque inflammation and by inference may determine vulnerability to rupture. Indeed, circulating IL-6 levels are elevated in patients with acute myocardial infarction (AMI), and also in patients with unstable, but not with stable angina. Coronary sinus IL-6 concentrations are also increased after percutaneous coronary intervention (PCI), and late restenosis correlates with an increase in IL-6 concentration after the procedure, indicating that IL-6 expression may be not only related to instability of atheromatous plaques, but also to the formation of restenotic lesions after PCI. These observations suggest the advantage of screening for circulating IL-6 concentration and the use of anti-inflammatory treatment for those thought be at high risk to reduce the risk of future AMI.

Angina Pectoris↗
PubMed2001

T2-weighted MRI of the female pelvis: comparison of breath-hold fast-recovery fast spin-echo and nonbreath-hold fast spin-echo sequences.

In 49 patients who had pelvic abnormalities, breath-hold T2-weighted fast-recovery (FR)-fast spin-echo (FSE) (imaging time = 24 sec) and nonbreath-hold FSE MR images (2 min 8 sec) were compared qualitatively (on a four-point scale) and quantitatively (using signal-to-noise ratios (SNRs) and contrast ratios (/SIs of the lesions-SIs of the myometrium/SIs of the myometrium)). Motion artifacts were reduced on breath-hold FR-FSE (3.8:3.2 = breath-hold FSE:nonbreath-hold FSE, P < 0.01) and image quality was comparable (3.8:3.7, NS). In all patients, pathology (leiomyoma [N = 26], adenomyosis [N = 10], endometrial carcinoma [N = 8], and ovarian cystic lesions [N = 21]) was recognized with comparable lesion conspicuity (3.8:3.7, NS) and better delineation of the structures (3.9:3.6, P < 0.05) on the FR-FSE images. There was no significant difference in contrast ratios, although SNRs (e.g., myometrium 18.3:25.8, P < 0.01) were better and the uterine zonal anatomy was recognized better on the nonbreath-hold FSE (3.4:3.7, P < 0.05). These differences did not affect the diagnosis. Breath-hold FR-FSE provides the benefits of motionless imaging and a short examination time, although lower SNRs were noted. J. Magn. Reson. Imaging 2001;13:930-937.

Adolescent↗
PubMed2001

Fat-suppressed T2-weighted MRI of the liver: comparison of respiratory-triggered fast spin-echo, breath-hold single-shot fast spin-echo, and breath-hold fast-recovery fast spin-echo sequences.

The purpose of our study was to compare the value of respiratory-triggered fast spin-echo, breath-hold single-shot fast spin-echo, and breath-hold fast-recovery fast spin-echo sequences in detecting hepatic lesions. Fat-suppressed T2-weighted magnetic resonance (MR) images obtained with the three sequences in 36 patients with 138 lesions and nine patients without lesions were prospectively analyzed. Quantitative and qualitative analyses, including receiver operating characteristic (ROC) analyses, were performed. The mean lesion-to-liver contrast-to-noise ratio (CNR) for hepatic lesions was highest with the respiratory-triggered fast spin-echo sequence. On the basis of receiver-operating characteristic analyses, tumor detection rates were higher with the breath-hold fast-recovery fast spin-echo sequence (Az = 0.94) than with the respiratory-triggered fast spin-echo sequence (AZ = 0.80, P < 0.0001) or the single-shot fast spin-echo sequence (Az = 0.77, P < 0.0001). The image quality with the breath-hold fast-recovery fast spin-echo sequence was acceptable in all patients. The breath-hold fast-recovery fast spin-echo sequence provided the highest tumor detection in a short imaging time, although the mean lesion-to-liver CNRs were inferior to those of the respiratory-triggered fast spin-echo and the breath-hold single-shot fast spin-echo sequences.

Adult↗