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N Okada

Publications and source records attributed to N Okada.

At least 37 records · Page 2Linked to original sources
PubMed2001

Matrix metalloproteinase-2 and -9 in bile as a marker of liver metastasis in colorectal cancer.

Matrix metallproteinases (MMP)-2 and -9 are associated with cancer invasion and metastasis. MMP-2 and MMP-9 activities have never been assayed in bile. In the present study we investigated whether MMP-2 and -9 activities in the bile could be a marker for evaluation of liver metastasis in colorectal cancer. Fifty-three patients underwent colorectal resection for histologically verified adenocarcinoma. Twenty-six patients had colorectal cancer without liver metastasis and 27 patients had metastatic liver tumor. Six patients were studied as carcinoma-free control. MMP-2 and MMP-9 activities were assayed in bile using gelatin zymography and quantitated. Active MMP-2 activity of colorectal cancer with liver metastasis group (24.1 +/- 2.5 pixel count) was significantly higher than that of colorectal cancer without liver metastasis group (11.4 +/- 1.3 pixel count) (P < 0.001) or of control group (6.4 +/- 1.0 pixel count) (P < 0.001). Active MMP-9 was not detected in bile. ProMMP-9 activity of colorectal cancer with liver metastasis group (530.3 +/- 127.5 pixel count) was significantly higher than that of colorectal cancer without liver metastasis group (213.9 +/- 33.2 pixel count) (P = 0.008). This is the first report showing that the levels of active MMP-2 and proMMP-9 in bile were significantly higher in liver metastasis of colorectal cancer than in metastasis-free colorectal cancer. The results suggest that activities of active MMP-2 and proMMP-9 in the bile may be useful markers for predicting liver metastasis in colorectal cancer.

Adenocarcinoma↗
PubMed2001

Absorption of water-soluble compounds with different molecular weights and.

The absorption of water soluble compounds with different molecular weights, such as phenol red (MW 354), trypan blue (MW 960), fluorescein isothiocyanate dextrans, (MW 4400 and 9100) was studied in the lung, nasal cavity, buccal cavity, small and large intestine of rats. For all the compounds, maximal absorption was observed when administered to the lung. The rank order of absorption of each compound from various administration sites was lung>small intestine> or =nasal cavity> or =large intestine> or =buccal cavity. In addition, the relationship between logarithm absorption % of the compounds from various administration sites and logarithm molecular weights of these compounds was examined. The absorption of compounds gradually decreased with increasing molecular weight for each site of administration. Moreover, the absorption of [Asu1.7]-eel calcitonin (ECT) from these sites and the effect of 10 mM sodium glycocholate, an absorption enhancer, on its absorption were also investigated in rats. When ECT alone was administered into these sites, the lung had the best absorption site of ECT, followed by the nasal cavity, the large intestine, the small intestine and the buccal cavity. Therefore, the absorption of ECT was also dependent on the administration site, although the rank order of absorption % of ECT was different from the other compounds. Sodium glycocholate (NaGC) remarkably increased ECT absorption from the small intestine, while we found marginal increase in its absorption from the lung even in the presence of NaGC. These findings provided useful fundamental information that might aid in the selection of administration routes for drugs of differing molecular weights including peptide drugs as far as the degree of drug absorption is concerned.

Absorption↗
PubMed2001

Effects of lipofectin-antigen complexes on major histocompatibility complex class I-restricted antigen presentation pathway in murine dendritic cells and on dendritic cell maturation.

We previously reported that exogenous antigens complexed with the cationic liposome lipofectin (LF) were efficiently presented via major histocompatibility complex (MHC) class I molecules on pulsed dendritic cells (DCs) in vitro. In the present study, we demonstrated that MHC class I-restricted antigen presentation on DC2.4 cells, a murine immature DC line, treated with LF-antigen complexes was remarkably suppressed through the inhibition of endocytosis, proteasome catalysis, and Golgi transport. We also found that LF did not influence expression of interleukin-12 p40 mRNA, MHC molecules, or co-stimulatory molecules in DC2.4 cells. These findings suggest that an antigen-loading procedure using LF could enhance delivery of exogenous antigens to the classical MHC class I pathway in DCs, but it does not initiate DC maturation.

Acetylcysteine↗
PubMed2001

Retroposon analysis of major cetacean lineages: the monophyly of toothed whales and the paraphyly of river dolphins.

SINE (short interspersed element) insertion analysis elucidates contentious aspects in the phylogeny of toothed whales and dolphins (Odontoceti), especially river dolphins. Here, we characterize 25 informative SINEs inserted into unique genomic loci during evolution of odontocetes to construct a cladogram, and determine a total of 2.8 kb per taxon of the flanking sequences of these SINE loci to estimate divergence times among lineages. We demonstrate that: (i) Odontocetes are monophyletic; (ii) Ganges River dolphins, beaked whales, and ocean dolphins diverged (in this order) after sperm whales; (iii) three other river dolphin taxa, namely the Amazon, La Plata, and Yangtze river dolphins, form a monophyletic group with Yangtze River dolphins being the most basal; and (iv) the rapid radiation of extant cetacean lineages occurred some 28-33 million years B.P., in strong accord with the fossil record. The combination of SINE and flanking sequence analysis suggests a topology and set of divergence times for odontocete relationships, offering alternative explanations for several long-standing problems in cetacean evolution.

Animals↗
PubMed2001

Administration route-dependent vaccine efficiency of murine dendritic cells pulsed with antigens.

Dendritic cells (DCs) loaded with tumour antigens have been successfully used to induce protective tumour immunity in murine models and human trials. However, it is still unclear which DC administration route elicits a superior therapeutic effect. Herein, we investigated the vaccine efficiency of DC2.4 cells, a murine dendritic cell line, pulsed with ovalbumin (OVA) in the murine E.G7-OVA tumour model after immunization via various routes. After a single vaccination using 1 x 10(6)OVA-pulsed DC2.4 cells, tumour was completely rejected in the intradermally (i.d.; three of four mice), subcutaneously (s.c.; three of four mice), and intraperitoneally (i.p.; one of four mice) immunized groups. Double vaccinations enhanced the anti-tumour effect in all groups except the intravenous (i.v.) group, which failed to achieve complete rejection. The anti-tumour efficacy of each immunization route was correlated with the OVA-specific cytotoxic T lymphocyte (CTL) activity evaluated on day 7 post-vaccination. Furthermore, the accumulation of DC2.4 cells in the regional lymph nodes was detected only in the i.d.-and s.c.-injected groups. These results demonstrate that the administration route of antigen-loaded DCs affects the migration of DCs to lymphoid tissues and the magnitude of antigen-specific CTL response. Furthermore, the immunization route affects vaccine efficiency.

Animals↗
PubMed2001

Efficient gene delivery into dendritic cells by fiber-mutant adenovirus vectors.

Recent studies have demonstrated the usefulness of dendritic cells (DCs) genetically modified by adenovirus vectors (Ad) to immunotherapy, while sufficient gene transduction into DCs is required for high doses of Ad. The RT-PCR analysis revealed that the relative resistance of DCs to Ad-mediated gene transfer is due to the absence of Coxsackie-adenovirus receptor expression, and that DCs expressed adequate alpha(v)-integrins. Therefore, we investigated whether fiber-mutant Ad containing the Arg-Gly-Asp (RGD) sequence in the fiber knob can efficiently transduce and express high levels of the LacZ gene into DCs. The gene delivery by fiber-mutant Ad was more efficient than that by conventional Ad in both murine DC lines and normal human DCs (NHDC). Furthermore, NHDC transduced with fiber-mutant Ad and conventional Ad at 8000-vector particles/cell resulted in a 70-fold difference in beta-galactosidase activity. We propose that alpha(v)-integrin-targeted Ad is a very powerful tool with which to implement DC-based vaccination strategies.

Adenoviridae↗
PubMed2001

Enhanced absorption of insulin and (Asu(1,7))eel-calcitonin using novel azopolymer-coated pellets for colon-specific drug delivery.

The objective of this study was to estimate colon-specific delivery of insulin and (Asu(1,7))eel-calcitonin using novel azopolymer-coated pellets. In vitro drug-release experiments from the azopolymer-coated pellets containing fluorescein isothiocyanate dextran (MW 4400; FD-4) were carried out by the Japanese Pharmacopoeia (J.P.) XIII rotating basket method with some slight modifications. Little release of FD-4 from the pellets was observed in phosphate buffered saline. However, the release of FD-4 was markedly increased in the presence of rat cecal contents. The intestinal absorption of insulin and (Asu(1,7))eel-calcitonin after oral administration of the azopolymer-coated pellets containing these peptides with camostat mesilate was evaluated by measuring the hypoglycemic and hypocalcemic effects, respectively. A slight decrease in plasma glucose levels was observed following the oral administration of these pellets containing 12.5 IU of insulin compared with the same dose of insulin solution. Camostat mesilate, a protease inhibitor that is incorporated with insulin in these pellets, further decreased the plasma glucose levels in a dose-dependent manner. Similar results were also obtained with the oral administration of pellets containing (Asu(1,7))eel-calcitonin. These findings suggest that azopolymer-coated pellets may be useful carriers for the colon-specific delivery of peptides including insulin and (Asu(1,7))eel-calcitonin.

Administration, Oral↗
PubMed2001

Membrane complement regulators protect against the development of type II collagen-induced arthritis in rats.

OBJECTIVE: To investigate changes in the distribution patterns of membrane complement regulators (MCRs) during the development of type II collagen-induced arthritis (CIA) and to examine the protective effects of these molecules against the augmentation of CIA in the knee joint. METHODS: Immunohistochemistry was used to examine the distribution of the MCRs Crry, DAF, and CD59 in the synovium of knee joints before and 2, 4, and 10 weeks after induction of CIA by immunization with type II collagen. In addition, at 2 or 10 weeks after induction of CIA, rats were injected intraarticularly with anti-Crry and/or anti-CD59 as the F(ab')2 fraction of monoclonal antibodies (mAb). Knee joint swelling and histologic changes in the synovium were examined 2 weeks after mAb injection. RESULTS: Synovial expression of Crry, DAF, and CD59 decreased in parallel with increased inflammation. When Crry and CD59 were functionally blocked at 2 weeks after the induction of CIA, swelling of the knee joints was markedly increased. Blocking of either regulator alone had no effect on swelling. Thickening of the synovial surface and proliferation of subsynovial tissue were all increased after blocking Crry and CD59, whereas blocking of either MCR alone had no effect. When both Crry and CD59 were blocked, deposits of membrane attack complex were found in the synovium. CONCLUSION: Our findings indicate that in rats with CIA and severely inflamed synovium, local expression of MCR is reduced. The MCRs Crry and CD59 appear to suppress the development of CIA.

Animals↗
PubMed2001

Evolution of CHR-2 SINEs in cetartiodactyl genomes: possible evidence for the monophyletic origin of toothed whales.

Short interspersed repetitive elements (SINEs) are a kind of retroposons dispersed among the eukaryotic genomes. Previously, we isolated and characterized a new SINE family, named CHR-2, members of which are distributed in the genomes of cetaceans, hippopotamuses, and ruminants. We analyzed systematically more than a hundred members of the CHR-2 SINEs, which were isolated from the genomes of cetaceans and cow, together with the additional data available in the DNA databases, and showed that these SINEs are divided into at least five distinct subfamilies that share diagnostic nucleotides and/or deletions. A hybridization analysis clearly demonstrated that, among these five subfamilies, two subfamilies, named CD and CDO, are specific to cetaceans and toothed whales, respectively. We reconstruct the evolutionary history of the CHR-2 SINEs during evolution of cetartiodactyl genomes.

Animals↗
PubMed2001

Asymmetrical development of bones and soft tissues during eye migration of metamorphosing Japanese flounder, Paralichthys olivaceus.

The symmetrical body of flatfish larvae dramatically changes into an asymmetrical form after metamorphosis. Eye migration results in the most significant asymmetrical development seen in any vertebrate. To understand the mechanisms involved in eye migration, bone and cartilage formation was observed during metamorphosis in laboratory-reared Japanese flounder, Paralichthys olivaceus, by using whole-body samples and histological sections. Most of the hard tissues of the cranium (parasphenoid, trabecular cartilage, supraorbital canal, and supraorbital bar) exist symmetrically in the larval period before metamorphosis and develop by twisting in the same direction as that in which the eye migrates. An increase in skin thickness beneath the eye was observed only on the blind side at the beginning of eye migration; this was the first definitive difference between the right and left sides of the body. The pseudomesial bar, a peculiar bone present only in flatfishes, developed from this thick skin and grew dorsad. Novel sac-like structures were found and named retrorbital vesicles. The retrorbital vesicle of the blind side grew larger and faster than that of the ocular side when the right eye moved most dramatically, whereas no difference was observed between the volume of right and left connective tissue in the head. The asymmetrical presence and growth of the pseudomesial bar together with inflation of the retrorbital vesicle on the blind side may be responsible for right eye migration during metamorphosis in the Japanese flounder.

Animals↗
PubMed2001

Physiological function of bromoperoxidase in the red marine alga, Corallina pilulifera: production of bromoform as an allelochemical and the simultaneous elimination of hydrogen peroxide.

The physiological function of vanadium-bromoperoxidase (BPO) in the marine red alga, Corallina pilulifera, has been characterized from the viewpoint of allelochemical formation. The algae emit bromoform (CHBr3) depending on the enzyme activity level in vivo (Itoh, N., Shinya, M., 1994. Seasonal evolution of bromomethanes from coralline algae and its effect on atmospheric ozone. Marine Chemistry 45, 95-103). We demonstrated that bromoform produced by C. pilulifera played an important role in eliminating epiphytic organisms, especially microalgae on the surface. Such data suggest a strong relationship between the coralline algae and the coralline flat (deforested area in the marine environment: called isoyake in Japanese). Lithophyllum yessoense, the main inhabitant of coralline flats in Japan, produced a lower level of CHBr3 than C. pilulifera, and showed BPO activity. On the other hand, the seasonal change of BPO activity in C. pilulifera in vivo was in proportion to superoxide dismutase (SOD) activity and in inverse proportion to catalase activity. The phenomenon implies that BPO could be a potential substitute for catalase, because the enzyme catalyzes an efficient Br(-)-dependent catalase reaction.

Benzopyrans↗
PubMed2001

cDNA of a novel mRNA expressed predominantly in mouse kidney.

We examined embryonic carcinoma (EC) cells for a potential prototype molecule of C3, the third component of complement. PCR primers, corresponding to the base sequence derived from the C3 cDNA of several species, were used for PCR amplification of the EC cell cDNA. All the PCR products obtained had the same sequence and showed no sequence homology to C3. Subsequently, cDNA clones were isolated from a mouse liver cDNA library using the PCR product as a probe. Unexpectedly, neither the base sequence of the cDNA clones nor the amino acid sequence deduced from the cDNA showed homology to C3, although partial homology was observed to a number of sequences from EST databases. We designated this new clone NCU-G1. Northern hybridization experiments revealed that NCU-G1 is expressed constitutively not only in the mouse fetus but also in various mouse tissues, and is most abundant in the kidney cortex.

Amino Acid Sequence↗
PubMed2001

Carboxypeptidase R is an inactivator of complement-derived inflammatory peptides and an inhibitor of fibrinolysis.

Carboxypeptidase R (CPR) exists in precursor form (proCPR) in plasma in contrast to carboxypeptidase N (CPN), which is present in the active state. CPR plays two important roles, one of which appears to be the control of the inflammatory response by inactivation of anaphylatoxins such as complement-derived C3a and C5a. Therefore, an increase in CPR activity may facilitate rapid inactivation of these inflammatory mediators generated at the site of bacterial infection. Upregulation of proCPR expression during the inflammatory response initiated for instance by endotoxin (lipopolysaccharide) should play a role in suppressing hyper-reactivity as seen in septic shock. CPR also functions as an inhibitor of fibrinolysis, where its ability to prevent binding of plasminogen to lysine residues on fibrin clots significantly lengthens tissue plasminogen activator (tPA)-induced fibrinolysis time. Therefore, upregulation of proCPR production during the inflammatory response may exacerbate thrombosis contributing to the development of disseminated intravascular coagulation as well as other conditions involving thrombosis. Co-administration of tPA and a specific inhibitor of CPR, such as potato carboxypeptidase inhibitor, which does not affect CPN, may be useful in thrombolytic therapy.

Anaphylatoxins↗
PubMed2001

Comparison of apoptosis and apoptosis-related gene products between extranodal oral B-cell lymphoma and maxillofacial nodal B-cell lymphoma.

Twenty-seven cases of primary extranodal oral B-cell lymphoma and 22 cases of primary maxillofacial nodal B-cell lymphoma were investigated for the presence of apoptotic cells and the expression of apoptosis-related gene products by terminal deoxynucleotidyl-mediated dUTP nick end labeling (TUNEL) and immunohistochemistry. The majority of extranodal oral diffuse large B-cell lymphomas (17/25, 68%) and maxillofacial nodal diffuse large B-cell lymphomas (14/16, 88%) contained no or less than 10% apoptotic cells. Whereas the majority of extranodal oral diffuse large B-cell lymphomas (18/25, 72%) and maxillofacial nodal diffuse large B-cell lymphomas (13/16, 81%) contained more than 10% of Ki-67-positive cells. Bcl-2-, Bax-, p53- and Ki-67-positive rates were higher in maxillofacial nodal diffuse large B-cell lymphomas than in extranodal oral diffuse large B-cell lymphomas, but only Bax (chi2 test, 0.01<P<0.025) and p53 (chi2 test, 0.005<P<0.01) had significant differences. Extranodal oral diffuse large B-cell lymphomas had a higher frequency of TUNEL expression than maxillofacial nodal diffuse large B-cell lymphomas. In maxillofacial nodal diffuse large B-cell lymphomas, stage III and stage IV tumors had a significantly higher frequency of Bcl-2 expression than stage I and stage II tumors (Fisher's exact test, P<0.01). These findings indicated that in the majority of both extranodal oral and maxillofacial nodal diffuse large B-cell lymphomas, apoptosis was inhibited - whereas proliferative activity was accelerated. Impairment of apoptosis and apoptotic related gene products may have a more important relation to maxillofacial nodal diffuse large B-cell lymphoma than extranodal oral diffuse large B-cell lymphoma.

Apoptosis↗
PubMed2001

High-resolution magnetic resonance imaging of squamous cell carcinoma of the tongue: an in vitro study.

OBJECTIVES: To determine in vitro the potential of high-resolution MRI for evaluating the depth of tumor invasion of the tongue. METHODS: Twenty-one resected specimens of squamous cell carcinoma of the tongue were examined on a 1.5T MRI system with a 4 cm surface coil using four different sequences; T1W SE, T2W SE, 3D-FISP and 3D-CISS. The thickness of normal epithelium, tumor depth and width were measured on both MR images and histopathological sections. RESULTS: The mucosal epithelium, lamina propria and muscles of the tongue were clearly identifiable on MRI. All 21 carcinomas, including three early invasive carcinomas, were clearly demonstrated. A high correlation was found between the values measured by MRI and histopathology for thickness of mucosal epithelium and both depth and width of tumors. There was a good agreement between the T2W SE and the other imaging sequences for measurements of both depth and width of tumors. CONCLUSION: High-resolution MR imaging appears reliable for the in vitro evaluation of depth of tumor invasion in carcinoma of the tongue.

Adult↗
PubMed2001

Characterization of glycosylphosphatidylinositol-anchored decay accelerating factor (GPI-DAF) and transmembrane DAF gene expression in wild-type and GPI-DAF gene knockout mice using polyclonal and monoclonal antibodies with dual or single specificity.

Decay-accelerating factor (DAF, CD55) is a glycosylphosphatidylinositol (GPI)-linked membrane inhibitor of complement activation. While human and other mammalian species contain only one DAF gene, two distinct DAF genes, referred to as GPI-DAF and transmembrane (TM)-DAF, respectively, have been identified in the mouse. Using several independently generated monoclonal and polyclonal antibodies, either with dual or single specificity for GPI-DAF and TM-DAF gene products, we have examined the expression of the two DAF genes in tissues of the wild-type and a strain of knockout mouse whose GPI-DAF gene has been inactivated. By fluorescence-activated cell sorting (FACS) analysis, we found that DAF protein is present on the wild-type mouse erythrocytes and lymphocytes but no signal was detectable on the same cells of GPI-DAF gene knockout mice. Both T and B lymphocytes and splenic macrophages express the GPI-DAF gene but the expression level is higher on B lymphocytes than on T lymphocytes. Within the T cell population, both CD4+ and CD8+ T cells are positive. DAF protein was detected by immunohistochemistry at high levels on wild-type mouse spermatids and mature sperm. In contrast, only mature sperm stained positive in the GPI-DAF gene knockout mouse testis, suggesting that GPI-DAF but not the TM-DAF gene is expressed on spermatids. Examination of the fetoplacental unit at the day 7.5 stage revealed that GPI-DAF but not the TM-DAF gene is expressed in the maternal decidua cells surrounding the trophoectoderm of the embryo. No DAF expression was detected on trophoblast or the embryo proper. These findings suggest that although the TM-DAF gene is irrelevant on mouse blood cells, the two DAF genes may have different roles in germ cell development and/or mature sperm function. Because complement receptor 1-related gene/protein y (Crry) has been shown to be expressed on early mouse embryos, the complete lack of GPI-DAF and TM-DAF gene expression in early mouse development may explain the observed sensitivity of Crry-deficient embryos to maternal complement attack.

Animals↗
PubMed2001

Tissue distribution of products of the mouse decay-accelerating factor (DAF) genes. Exploitation of a Daf1 knock-out mouse and site-specific monoclonal antibodies.

Decay-accelerating factor (DAF) is a membrane regulator of C3 activation that protects self cells from autologous complement attack. In humans, DAF is uniformly expressed as a glycosylphosphatidylinositol (GPI)-anchored molecule. In mice, both GPI-anchored and transmembrane-anchored DAF proteins are produced, each of which can be derived from two different genes (Daf1 and Daf2). In this report, we describe a Daf1 gene knock-out mouse arising as the first product of a strategy for targeting one or both Daf genes. As part of the work, we characterize recently described monoclonal antibodies against murine DAF protein using deletion mutants synthesized in yeast, and then employ the monoclonal antibodies in conjunction with wild-type and the Daf1 knock-out mice to determine the tissue distribution of the mouse Daf1 and Daf2 gene products. To enhance the immunohistochemical detection of murine DAF protein, we utilized the sensitive tyramide fluorescence method. In wild-type mice, we found strong DAF labelling of glomeruli, airway and gut epithelium, the spleen, vascular endothelium throughout all tissues, and seminiferous tubules of the testis. In Daf1 knock-out mice, DAF labelling was ablated in most tissues, but strong labelling of the testis and splenic dendritic cells remained. In both sites, reverse transcription-polymerase chain reaction analyses identified both GPI and transmembrane forms of Daf2 gene-derived protein. The results have relevance for studies of in vivo murine DAF function and of murine DAF structure.

Animals↗