Biomedical subjects

H Kitano

Publications and source records attributed to H Kitano.

At least 19 recordsLinked to original sources

PubMed2006

Comparative studies of suppression of malignant cancer cell phenotype by antisense oligo DNA and small interfering RNA.

One of the distinguishing features of malignant tumor cells is the ability to proliferate in an anchorage-independent manner; methods that effectively suppress this phenotype may be applicable to the therapeutic inhibition of the malignancy of cancers. Interfering RNA is a potentially powerful tool for cancer therapy because of its specificity of target selection and remarkably high efficiency in target mRNA suppression. We studied the use of two knockdown strategies, antisense oligo DNA (AS-ODN) and small interfering RNA (siRNA), and showed how the anchorage-independent proliferation of malignant cells could be blocked efficiently. Anchorage-independent proliferation of rat fibroblasts transformed with v-src was suppressed with only a single 1-microM dose of AS-ODN; similar suppression using siRNA required treatment with 1 nM siRNA every 12 h. With our experimental system, the molecular stability of AS-ODN allowed the use of a simple treatment regimen to control the amount of the target molecule, providing that the treatment dose was sufficiently high. In comparison, siRNA treatment was effective at lower doses, but more frequent treatment was necessary to achieve the same suppression of proliferation.

Animals↗

PubMed2005

The transcriptional landscape of the mammalian genome.

This study describes comprehensive polling of transcription start and termination sites and analysis of previously unidentified full-length complementary DNAs derived from the mouse genome. We identify the 5' and 3' boundaries of 181,047 transcripts with extensive variation in transcripts arising from alternative promoter usage, splicing, and polyadenylation. There are 16,247 new mouse protein-coding transcripts, including 5154 encoding previously unidentified proteins. Genomic mapping of the transcriptome reveals transcriptional forests, with overlapping transcription on both strands, separated by deserts in which few transcripts are observed. The data provide a comprehensive platform for the comparative analysis of mammalian transcriptional regulation in differentiation and development.

3' Untranslated Regions↗

PubMed2005

Nanoscale friction: kinetic friction of magnetic flux quanta and charge density waves.

In analogy with the standard macroscopic friction, here we present a comparative study of the friction force felt by moving vortices in superconductors and charge density waves. Using experiments and a model for this data, our observations (1) provide a link between friction at the micro- and macroscopic scales, (2) explain the roundness of the static-kinetic friction transition in terms of thermal fluctuations, particle interactions, and system size (critical-phenomena view), and (3) explain the crossing of the kinetic friction F(k) versus velocity V for our pristine (high density of very weak defects) and our irradiated samples (with lower density of deeper pinning defects).

Journal Article↗

PubMed2005

Use of real-time magnetic resonance image guidance in endoscopic sinus surgery.

We evaluated the effectiveness of magnetic resonance image (MRI) guidance using an optical tracking system (MRI-guided therapy: MRT) in performing endoscopic sinus surgery (ESS). The profiles of the fourteen patients in the present study were as follows: eleven with mucocele in the paranasal sinus, one with recurrent chronic sinusitis, one with maxillary cancer, and one with Graves' ophthalmopathy. Preparation of the MRT system required an additional 54 min in cases involving general anesthesia, and an additional 17 min in cases involving local anesthesia, in comparison with corresponding control groups undergoing ESS in a traditional operating room. We developed nonmetal probes that were visualized in a real-time mode and assistive devices for the optical tracking system that were equipped to avoid obstruction caused by surgical instruments as well as by the hands of surgeons. Using these unique devices, anatomic landmarks were visualized using the present MRT system. The prognosis of patients was favorable, and in particular, no patients with sinus mucocele showed a recurrence of their lesions. We concluded that the MRT system used here for performing ESS was beneficial, especially in terms of the intranasal marsupialization of sinus mucoceles and for the verification of orbital contents.

Journal Article↗

PubMed2005

Changes in thymus- and activation-regulated chemokine (TARC) associated with allergen immunotherapy in patients with perennial allergic rhinitis.

BACKGROUND: Thymus- and activation-regulated chemokine (TARC), which is a CC chemokine receptor (CCR) 4 ligand with ability to recruit Th2 cells to inflammatory sites, is pathogenetically important in allergic rhinitis. Specific immunotherapy (IT), among the most effective therapies for allergic rhinitis, has incompletely understood mechanisms of action. TARC might be involved in some benefits of IT. METHODS: TARC in sera was assayed, obtained from 50 patients with house dust mite allergic rhinitis before and 1 year after beginning IT. Their ages ranged from 6 to 34 years (mean, 10), 30 were male and 20 were female. RESULTS: In patients whose nasal obstruction responded to IT, TARC decreased significantly with IT, while when response was defined in terms of sneezing or rhinorrhea, TARC did not change significantly. CONCLUSION: TARC might be an important target of IT in reducing obstructive allergic rhinitis.

Adolescent↗

PubMed2004

ORP150 ameliorates ischemia/reperfusion injury from middle cerebral artery occlusion in mouse brain.

The 150-kDa oxygen-regulated protein (ORP150), a novel stress protein localized to the endoplasmic reticulum (ER), is induced by hypoxia/ischemia. To determine the role of ORP150 in cerebral infarction following ischemia/reperfusion, ORP150 transgenic (TG) and knockout (KO) mice were subjected to 1 or 3 h of middle cerebral artery (MCA) occlusion followed by reperfusion for 24 h. At 24 h after 1 h of occlusion, significantly less infarct volume was evident in cerebral cortex, but not in striatum, in ORP150TG than ORP150KO mice (P<0.001). Infarct volume did not differ significantly between these groups at 24 h after 3 h of occlusion. Immunohistochemical reactivity for microtubule-associated protein (MAP)2 in the MCA territory was lost in ORP150KO mice at 24 h after 1 h of occlusion. In contrast, MAP2 staining still was present in the affected cortex of ORP150TG mice, where markedly enhanced ORP150 immunoreactivity was demonstrated. MAP2 staining had disappeared from the affected area at 24 h after 3 h of occlusion in both groups, but astrocytic ORP150 reactivity was preserved in the ORP150TG group. At 6 h after 1-h occlusion, when MAP2 staining was evident in the affected cortex, some cortical neurons of the TG mice were reactive for Bcl-xS/L. Thus, ORP150 may be cytoprotective against ischemia/reperfusion injury via reduction of ER stress and probably also inhibition of apoptosis.

Animals↗

PubMed2004

Evolving a lingua franca and associated software infrastructure for computational systems biology: the Systems Biology Markup Language (SBML) project.

Biologists are increasingly recognising that computational modelling is crucial for making sense of the vast quantities of complex experimental data that are now being collected. The systems biology field needs agreed-upon information standards if models are to be shared, evaluated and developed cooperatively. Over the last four years, our team has been developing the Systems Biology Markup Language (SBML) in collaboration with an international community of modellers and software developers. SBML has become a de facto standard format for representing formal, quantitative and qualitative models at the level of biochemical reactions and regulatory networks. In this article, we summarise the current and upcoming versions of SBML and our efforts at developing software infrastructure for supporting and broadening its use. We also provide a brief overview of the many SBML-compatible software tools available today.

Biochemistry↗

PubMed2004

Two cases of colonic tuberculosis presenting with massive melena.

The clinical symptoms of colonic tuberculosis are variable, among which massive melena is extremely rare. Herein, we report two cases of colonic tuberculosis representing with massive melena, both of whom never had active pulmonary tuberculosis. The first case was a 55-year-old woman. Although her emergency colonoscopic setting suggested colonic tuberculosis, no evidence of tuberculosis could be found at that time. We performed a therapeutic trial and observed a drastic regression of the initial changes with 4-week treatment using antituberculous agents. The second case was a 37-year-old man. His emergency colonoscopy showed lesions mimicking colon carcinoma. However, the histological examinations did not indicate malignancy. The polymerase chain reaction of colonic biopsy specimen was positive for Mycobacterium tuberculosis. Similar to the first case, a significant improvement of the initial lesions was observed after 4-week treatment using antituberculous agents. Collectively, although the massive melena is a rare manifestation, tuberculosis of the colon should be suspected in the patients with such symptom.

Adult↗

PubMed2003

The systems biology markup language (SBML): a medium for representation and exchange of biochemical network models.

MOTIVATION: Molecular biotechnology now makes it possible to build elaborate systems models, but the systems biology community needs information standards if models are to be shared, evaluated and developed cooperatively. RESULTS: We summarize the Systems Biology Markup Language (SBML) Level 1, a free, open, XML-based format for representing biochemical reaction networks. SBML is a software-independent language for describing models common to research in many areas of computational biology, including cell signaling pathways, metabolic pathways, gene regulation, and others. AVAILABILITY: The specification of SBML Level 1 is freely available from http://www.sbml.org/

Database Management Systems↗

PubMed2003

Efficient 355-nm generation in CsB3O5 crystal.

We demonstrate UV generation in CSB3O5 (CBO) crystals grown by the top-seeded solution growth technique. 355-nm UV light was generated by use of a type II CBO crystal as a sum frequency of the fundamental light and the second harmonic of a nanosecond Nd:YVO4 laser. A 3.0-W output of the third-harmonic was obtained at a repetition rate of 31 kHz. The conversion efficiency from the fundamental light to the third harmonic reached 30%, which was 1.5 times higher than that obtained with a type II LiB3O5 crystal under the same experimental conditions.

Journal Article↗

PubMed2002

Green revolution: a mutant gibberellin-synthesis gene in rice.

The chronic food shortage that was feared after the rapid expansion of the world population in the 1960s was averted largely by the development of a high-yielding semi-dwarf variety of rice known as IR8, the so-called rice 'green revolution'. The short stature of IR8 is due to a mutation in the plant's sd1 gene, and here we identify this gene as encoding an oxidase enzyme involved in the biosynthesis of gibberellin, a plant growth hormone. Gibberellin is also implicated in green-revolution varieties of wheat, but the reduced height of those crops is conferred by defects in the hormone's signalling pathway.

Crops, Agricultural↗

PubMed2002

Evidence for insulating behavior in the electric conduction of (NH(3))K(3)C(60) systems.

Microwave study using the cavity perturbation technique revealed that the conductivity of the antiferromagnet (NH(3))K(3-x)Rb(x)C(60) at 200 K is already 3-4 orders of magnitude smaller than those of superconductors, K(3)C(60) and (NH(3))(x)NaRb(2)C(60), and that the antiferromagnetic compounds are insulators below 250 K without metal-insulator transitions. The striking difference in the magnitude of the conductivity between these materials strongly suggests that the Mott-Hubbard transition in the ammoniated alkali fullerides is driven by a reduction of lattice symmetry from face-centered-cubic to face-centered-orthorhombic, rather than by the magnetic ordering.

Journal Article↗

PubMed2002

The ERATO Systems Biology Workbench: enabling interaction and exchange between software tools for computational biology.

Researchers in computational biology today make use of a large number of different software packages for modeling, analysis, and data manipulation and visualization. In this paper, we describe the ERATO Systems Biology Workbench (SBW), a software framework that allows these heterogeneous application components--written in diverse programming languages and running on different platforms--to communicate and use each others' data and algorithmic capabilities. Our goal is to create a simple, open-source software infrastructure which is effective, easy to implement and easy to understand. SBW uses a broker-based architecture and enables applications (potentially running on separate, distributed computers) to communicate via a simple network protocol. The interfaces to the system are encapsulated in client-side libraries that we provide for different programming languages. We describe the SBW architecture and the current set of modules, as well as alternative implementation technologies.

Computational Biology↗

PubMed2001

Endoscopic thyroid resection using cutaneous elevation in lieu of insufflation.

BACKGROUND: Laparoscopic surgery to resect cervical masses has gained increasing acceptance during the past decade. This report describes the authors' technique and experience using total video endoscopic surgery to resect thyroid masses. METHODS: The video camera is introduced through a 12-mm trocar inserted via a 10-mm infraclavicular incision in the sternal line. This incision will be hidden by the patient's undergarments postoperatively. An incision for a 12-mm trocar is made in each axilla, with additional incisions in the anterior chest made as necessary for the endoscope and instruments. Excellent exposure is produced by elevating the skin with hooks rather than by using carbon dioxide insufflation. This method reduces the incidence of subcutaneous emphysema and pneumomediastinum. RESULTS: Twenty-two thyroid lesions were resected using total video endoscopic surgery (adenoma, 13; cancer, 5; benign cyst, 3; and Graves' disease, 1). Procedures included thyroidectomy (12), thyroidectomy and isthmusectomy (4), and subtotal thyroidectomy (2). Subtotal cervical adenectomy was performed in 3 patients with papillary carcinoma. Cosmetic results were excellent. CONCLUSION: Endoscopic surgery of the neck is safe, minimally invasive, and produces excellent cosmetic results. However, it is in an early stage of development. Techniques have yet to be standardized, and specialized instruments are not available. The field is likely to mature as surgeons gain more experience.

Adenoma↗

PubMed2001

Neuronal expression of mint1 and mint2, novel multimodular proteins, in adult murine brain.

Mints are multimodular adapter proteins in functioning membrane transport and organization. Mint1 and mint2 are neuron-specific. We localized these isoforms in mouse brain. By in situ hybridization, mRNA encoding mint1 or mint2 was expressed in neurons throughout the brain. Mint1 mRNA expression was greatest in the limbic system including cingulate cortex, hippocampus, anterior thalamic nuclei, medial habenular nucleus, and mammillary body. Mint2 mRNA was rich in cerebral cortex, entorhinal cortex, and hippocampus, but less prominent in other limbic structures. Mint1 mRNA and mint2 mRNA were distributed among hippocampal pyramidal neurons, while mint2 mRNA was especially abundant in CA3. Mint1, but not Mint2 mRNA was abundant in the substantia nigra pars compacta. Immunohistochemistry visualized mint proteins in axon terminals and neuronal somata, generally following mRNA distribution. In the hippocampus, mint1 was rich in the entorhinal projections and mossy fibers of the dentate gyrus, while mint2 was rich in commisural fibers from the contralateral hippocampus and in CA1. Mint1 intensely stained catecholamine-containing neurons such as the substantia nigra pars compacta, ventral tegmental area, and locus ceruleus. Mint2 protein was ubiquitous in these regions. Mint1 and mint2 distribution also differed elsewhere in the brainstem and in the cerebellum. Central nervous system neurons, then, predominantly express either mint1 or mint2. Mints may be involved in synaptic vesicle transport toward the active zone, also participating in transport of certain membrane proteins toward the postsynaptic density. Mint1 and mint2 may divide roles either regionally or depending on neuronal functional characteristics.

Adaptor Proteins, Signal Transducing↗

PubMed2001

Cloning and functional analysis of two gibberellin 3 beta -hydroxylase genes that are differently expressed during the growth of rice.

We have cloned two gibberellin (GA) 3 beta-hydroxylase genes, OsGA3ox1 and OsGA3ox2, from rice by screening a genomic library with a DNA fragment obtained by PCR using degenerate primers. We have used full-scan GC-MS and Kovats retention indices to show function for the two encoded recombinant fusion proteins. Both proteins show 3 beta-hydroxylase activity for the steps GA(20) to GA(1), GA(5) to GA(3), GA(44) to GA(38), and GA(9) to GA(4). In addition, indirect evidence suggests that the OsGA3ox1 protein also has 2,3-desaturase activity, which catalyzes the steps GA(9) to 2,3-dehydro-GA(9) and GA(20) to GA(5) (2,3-dehydro GA(20)), and 2 beta-hydroxylase activity, which catalyzes the steps GA(1) to GA(8) and GA(4) to GA(34). Molecular and linkage analysis maps the OsGA3ox1 gene to the distal end of the short arm of chromosome 5; the OsGA3ox2 gene maps to the distal end of the short arm of chromosome 1 that corresponds to the D18 locus. The association of the OsGA3ox2 gene with the d18 locus is confirmed by sequence and complementation analysis of three d18 alleles. Complementation of the d18-AD allele with the OxGA3ox2 gene results in transgenic plants with a normal phenotype. Although both genes show transient expression, the highest level for OsGA3ox1 is from unopened flower. The highest level for OsGA3ox2 is from elongating leaves.

Amino Acid Sequence↗

PubMed2001

Robust oscillations within the interlocked feedback model of Drosophila circadian rhythm.

A mechanism for generating circadian rhythms has been of major interest in recent years. After the discovery of per and tim, a model with a simple feedback loop involving per and tim has been proposed. However, it is recognized that the simple feedback model cannot account for phenotypes generated by various mutants. A recent report by Glossop, Lyons & Hardin [Science286, 766 (1999)] on Drosophila suggests involvement of another feedback loop by dClk that is interlocked with per-tim feedback loop. In order to examine whether interlocked feedback loops can be a basic mechanism for circadian rhythms, a mathematical model was created and examined. Through extensive simulation and mathematical analysis, it was revealed that the interlocked feedback model accounts for the observations that are not explained by the simple feedback model. Moreover, the interlocked feedback model has robust properties in oscillations.

Animals↗

PubMed2001

Performance assessment of O-18 water purifier.

In the synthesis of 18F-FDG by the nucleophilic substitution method, 18O-H2O is usually used as target water. The target water should be recovered after synthesis and reused, because it is expensive, but recovered water contains impurities such as organic substances, and it must be purified before reuse. For this reason Sumitomo Heavy Industries, Ltd. developed an O-18 water purifier for elimination of organic substances in recovered water. This instrument consists of a UV irradiation unit and low-temperature distillation unit. Our institution had an opportunity to test use this instrument and evaluated its performance. The concentrations of organic substances after UV irradiation was greatly reduced, and recovery efficiency after distillation by the low-temperature distillation unit was very satisfactory at 99.3 +/- 0.5%. Furthermore, the yield of 18F-FDG from 18O-H20 purified with this instrument was sufficient for the clinical use.

Fluorodeoxyglucose F18↗