Search PubMed⌕ Search

Biomedical subjects

Y Endo

Publications and source records attributed to Y Endo.

At least 55 records · Page 3Linked to original sources
PubMed2001

Identification and quantification of molecular species of diacyl glyceryl ether by reversed-phase high-performance liquid chromatography with refractive index detection and mass spectrometry.

We have developed a method to identify and quantify the molecular species of diacyl glyceryl ether (DAGE) using high-performance liquid chromatography (HPLC) equipped with a refractive index detector and an electrospray ionization and time of flight mass spectrometer (LC-RI-MS). An octadecyl silica column with a mixture of acetonitrile and dichloromethane (65:35, v/v) as an eluant was used for the HPLC. When the LC-RI-MS method was applied to a mixture of synthetic DAGEs; 1-O-hexadecyl-2,3-dioleoylglycerol (O-16:0-18:1-18:18:1), 1-O-octadecyl-2,3-dioleoylglycerol (O-18:0-18:1-18:1), 1-O-octadecenyl-2,3-dioleoylglycerol (O-18:1-18:1-18:1), 1-O-octadecyl-2,3-didocodahexaenoylglycerol (O-18:0-22:6-22:6), and 1-O-octadecenyl-2,3-didocosahexaenoylglycerol (O-18:1-22:6-22:6), good separation and quantification were obtained on the refractive index chromatogram. A pseudo-molecular ion [M+NH4]+ and a monoacyl glyceryl ether ion [M-RCO2] + were observed for all synthetic DAGEs on the mass spectrum. It was found that the fatty acids and glyceryl ether in DAGE could be easily identified by these mass spectra. When this LC-RI-MS method was applied to the DAGEs extracted from muscle of Stromateus stellatus, approximately 18 peaks were observed on LC-RI-MS chromatograms and the major molecular species of DAGEs were identified as O-16:0-18:1-18:1.

Animals↗
PubMed2001

Macrophage are the principal reservoir and sustain high virus loads in rhesus macaques after the depletion of CD4+ T cells by a highly pathogenic simian immunodeficiency virus/HIV type 1 chimera (SHIV): Implications for HIV-1 infections of humans.

The highly pathogenic simian immunodeficiency virus/HIV type 1 (SHIV) chimeric virus SHIV(DH12R) induces a systemic depletion of CD4(+) T lymphocytes in rhesus monkeys during the initial 3-4 weeks of infection. Nonetheless, high levels of viral RNA production continue unabated for an additional 2-5 months. In situ hybridization and immunohistochemical analyses revealed that tissue macrophage in the lymph nodes, spleen, gastrointestinal tract, liver, and kidney sustain high plasma virus loads in the absence of CD4(+) T cells. Quantitative confocal immunofluorescence analysis indicated that greater than 95% of the virus-producing cells in these tissues are macrophage and less than 2% are T lymphocytes. Interestingly, the administration of a potent reverse transcriptase inhibitor blocked virus production during the early T cell phase but not during the later macrophage phase of the SHIV(DH12R) infection. When interpreted in the context of HIV-1 infections, these results implicate tissue macrophage as an important reservoir of virus in vivo. They become infected during the acute infection, gradually increase in number over time, and can be a major contributor to total body virus burden during the symptomatic phase of the human infection.

Adenine↗
PubMed2001

Field-inversion electrophoresis on a microchip device.

We have proposed a field-inversion electrophoresis on a microchip for a shorter effective length, and investigated the external frequency for the DNA analysis based on the field-inversion electrophoresis device. By using the optimized frequency, we demonstrated that the field-inversion electrophoresis has great potentials for the separation of DNA fragments with shorter effective length.

DNA, Single-Stranded↗
PubMed2001

Amino acids protect epithelial cells from local toxicity by absorption enhancer, sodium laurate.

To develop the safe absorption-enhancing formulation attenuating the local toxicity caused by an absorption enhancer, sodium laurate (C12), the effects of amino acids on the local toxicity by C12 were examined in rats. The absorption of phenol red, an unabsorbable marker drug, was significantly enhanced by 10 mM C12 in an in situ colon loop study and the addition of L-glutamine (L-Gln), L-arginine, or L-methionine at 10 mM did not change the promoting effect of C12. However, C12 significantly increased the elution of phospholipids, total protein, and lactate dehydrogenase, which are markers for local toxicity, from colon, but these amino acids attenuated the local toxicity caused by C12 significantly. Transport study using an Ussing-type chamber showed that the permeability of colonic membrane to phenol red was significantly enhanced by C12 and that L-Gln did not decrease the permeability enhanced by C12. Transmucosal electrical resistance was extensively decreased by C12, indicating that C12 could enhance the drug absorption at least partly by expanding the paracellular route. L-Gln significantly, but not completely, recovered resistance lowered by C12. Electrical potential difference was markedly reduced by C12, suggesting that C12 lowered the viability of mucosal cells, but 10 mM L-Gln significantly recovered potential difference almost to the control level. These results suggested the possibility that absorption-enhancing formulation with low local toxicity, which is low enough to be used practically, could be developed by using an amino acid like L-Gln as an ingredient attenuating the local toxicity caused by C12.

Amino Acids↗
PubMed2001

Water drinking causes a biphasic change in blood composition in humans.

To investigate precisely the fluid shifts associated with water drinking in humans, we measured continuously blood density and plasma electrolyte concentrations using the mechanical oscillator technique and ion-selective electrodes, respectively, in healthy young volunteers before (10 min) and after (48 min) water drinking for a period of 2 min. Beat-by-beat blood pressure was also monitored throughout the experiment. Drinking 1 l tap water caused a transient increase in blood density immediately after the drinking episode (from 1051.1+/-0.5 g/l before drinking to 1051.8+/-0.5 g/l 4 min after the start of drinking, P<0.05), followed by a gradual reduction (1050.1+/-0.5 g/l at 31 min). This drinking-induced change paralleled those of haematocrit, plasma density and plasma volume. Plasma [Na+] and [Cl-] and osmolality decreased after drinking without transient increases and reached minima at about 30 min. A transient increase in mean arterial blood pressure was observed prior to the increase in blood density. These findings suggest that water drinking causes a biphasic change in plasma volume: initial haemoconcentration, probably due to sympathetic acceleration, followed by haemodilution due to the post-absorptive effect, and further suggest that the fluid shift associated with the initial haemoconcentration is isosmotic.

Adult↗
PubMed2001

Wax ester biosynthesis in the liver of myctophid fishes.

The biosynthetic properties of wax esters in the liver were compared between two types of myctophid fishes having different body lipid composition, i.e., three triglyceride-rich species (Lampanyctus jordani, Diaphus theta, and Symbolophorus californiensis) and three wax ester-rich species (L. regalis, Stenobracius nannochir, and Stenobracius leucopsarus). n-Heptadecanol (17:0-ALC) and/or 10-cis-heptadecenoic acid (17:1-ACID) was incubated with liver homogenate of the six myctophid fishes and with co-factors such as NADPH and ATP for 2 to 5 h. Considerable amounts of wax esters with odd-numbered fatty acids and/or alcohols were produced in the liver homogenate of the wax ester-rich species. Stenobracius nannochir and L. regalis, which exclusively contained wax esters as neutral lipids, showed the highest activity of wax ester synthesis, followed by S. leucopsarus, which contained triglyceride as the minor constituent. Only trace amounts at most of odd-numbered fatty acids and alcohols were incorporated into the wax esters after incubation with the liver homogenates of the triglyceride-rich fishes. Active interchange between the fatty acids and the alcohols occurred during wax ester biosynthesis in the wax ester-rich fishes. The chain elongation and shortening of acyl moieties were also observed during incubation. These results suggested that the deposition of lipids in myctophid fishes is mainly due to their biosynthetic activities.

Adenosine Triphosphate↗
PubMed2001

Influences of cholinergic neurotoxin ethylcholine aziridinium ion on circadian rhythms in rats.

To investigate whether damages of cholinergic neurons in the brain produce aging-like changes in circadian rhythms, we examined the influences of intracerebroventricular injection of cholinergic neurotoxin ethylcholine aziridinium ion (AF64A, 5 nmol/5 microl) on circadian rhythms in rats, by measuring locomotor activity and body temperature with the automatic behavioral measurement system combined with the telemetry. Daily rhythms in locomotor activity and body temperature were observed in AF64A-treated rats under a 12:12 h light:dark (LD) cycle, however, in AF64A-treated rats, the amplitude of activity and temperature rhythms was significantly decreased, the phase of the both rhythms was advanced and the amount of activity was decreased, compared with control rats. Locomotor activity and body temperature also showed a circadian rhythm in AF64A-treated rats under the constant dark condition with the period similar to that in the control rats. The present findings are in accordance with the observation in aged animals in which cholinergic hypofunction are often observed, suggesting that hypofunctions of the cholinergic systems in the brain might be involved in aging-like changes in the circadian rhythms.

Acetylcholine↗
PubMed2001

Glucocorticoid hypersecretion following intracerebroventricular injection of ethylcholine mustard aziridinium ion in rats.

To investigate whether cholinergic hypofunctions in the brain influence hypothalamic-pituitary-adrenal activity, we examined the effects of cholinergic neurotoxin ethylcholine mustard aziridinium ion on basal and stress-induced levels of corticosterone in rats. Blood sampling from rats following intracerebroventricular injection of saline (5 microl, as a control) or this neurotoxin (5 nmol/5 microl) was performed over a day in one series, and was taken before, during and after an immobilization stress exposure in another series. Plasma levels of corticosterone and adrenocorticotropin were determined by the radioimmunoassay. The basal levels of plasma corticosterone and adrenocorticotropin over a day were significantly higher in the neurotoxin-treated rats, compared with the control rats (corticosterone, P<0.001; adrenocorticotropin, P<0.05). Further, relative adrenal gland weight of the neurotoxin-treated rats was significantly greater than that of the control rats (P<0.05). However, responses in plasma corticosterone level caused by the immobilization stress in the neurotoxin-treated rats were not different from those in the control rats. The present study demonstrated that damage to the cholinergic neurons in the brain increased hypothalamic-pituitary-adrenal activity over a day, probably due to freedom from inhibitory influences of the hippocampal cholinergic system, but that this damage did not influence stress-induced changes in plasma glucocorticoid level.

Adrenal Glands↗
PubMed2001

Enhanced throughput for DNA sequencing by capillary array electrophoresis with a gradient of electric field strength.

The effect of electric field gradients are examined on the speed, selectivity, read length, and accuracy for DNA sequencing using capillary array electrophoresis. Modified electric field gradients was realized to read over 800 bases within 140 min. The method developed is effectively applicable to single nucleotide polymorphism analysis for genomic drug discovery and pharmacogenomics.

Electrophoresis, Capillary↗
PubMed2001

Lymphangiogenesis and the vascular endothelial growth factor receptor (VEGFR)-3 in gastric cancer.

Vascular endothelial growth factor C (VEGF-C) is the only factor known to cause lymphangiogenesis. We studied the correlation between VEGF-C and vascular endothelial growth factor receptor-3 (VEGFR-3) expression of 85 primary gastric cancers by reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry, and the results were correlated with the number of lymphatic vessels, stained with anti-VEGFR-3 antibody. RT-PCR and immunohistology demonstrated that VEGF-C was mainly produced from cancer cells, but not from stromal elements. Morphologically, VEGFR-3 expression was detected in the endothelial cells of the stromal lymphatic vessels. There was a statistically positive correlation between the incidence of VEGF-C and VEGFR-3 mRNA expression in the primary tumours (P=0.0002). The number of VEGFR-3-positive lymphatic vessels in VEGF-C mRNA positive tumours was significantly larger than that in VEGF-C-negative tumours. The number of VEGFR-3-positive vessels in the tumour stroma was closely related to the grade of lymphatic invasion of gastric cancer. These results strongly indicate that VEGF-C may induce the proliferation of lymphatic vessels in the stroma of primary gastric cancer via activation of VEGFR-3, expressed on the endothelial cells of lymphatic vessels. In these circumstances, cancer cells can easily invade the lymphatic vessel, because of the increase of the contact points of cancer cells with the lymphatic vessels.

Blotting, Western↗
PubMed2001

Identification of a receptor type guanylyl cyclase in the antennal lobe and antennal sensory neurons of the silkmoth, Bombyx mori.

Sensory neuron-specific guanylyl cyclases (GC), which were recently identified in rodents and nematodes, are thought to be a new family of odorant/pheromone receptors. In the antennae of the male silkmoth Bombyx mori, receptor type GC are supposed to mediate signaling of pheromone. Structure of receptor type GC expressed in insect sensory neurons has remained unidentified. Here we report the isolation of cDNA of the receptor type GC, designated BmGC-I, from the male silkmoth antennae. The deduced amino acid sequence indicates that BmGC-I appears to consist of four domains: an extracellular, single transmembrane, kinase-like and a guanylyl cyclase domain. BmGC-I is most closely related to the mammalian natriuretic peptide hormone receptor A (GC-A) and retains all the cysteine residues that are conserved within the extracellular domain of the mammalian GC-As. Transcripts of the BmGC-I gene were detected in various tissues; the flight muscles, midgut, legs, ganglion, Malpighian tubules, testis and the head. Immunohistochemical study revealed that the BmGC-I protein localizes in the antennal-lobe glomerulus and in the soma and axon of sensory neurons. We thus suggest that BmGC-I plays functional roles in the odorant information processing and the modulation of excitability in the antennal sensory neurons.

Amino Acid Sequence↗
PubMed2001

Potent estrogen agonists based on carborane as a hydrophobic skeletal structure. A new medicinal application of boron clusters.

BACKGROUND: Carboranes (dicarba-closo-dodecaboranes) are a class of carbon-containing polyhedral boron-cluster compounds having remarkable thermal stability and exceptional hydrophobicity. Applications of the unique structural and chemical properties offered by icosahedral carboranes in boron neutron capture therapy have received increasing attention over the past 30 years. However, these features of carboranes may allow another application as a hydrophobic pharmacophore in biologically active molecules that interact hydrophobically with receptors. RESULTS: We have designed candidate estrogen-receptor-binding compounds having carborane as a hydrophobic skeletal structure and synthesized them. The most potent compound bearing a carborane cage exhibited activity at least 10-fold greater than that of 17beta-estradiol in the luciferase reporter gene assay. Estrogen receptor-alpha-binding data for the compound were consistent with the results of the luciferase reporter gene assay. The compound also showed potent in vivo effects on the recovery of uterine weight and bone loss in ovariectomized mice. CONCLUSION: Further development of the potent carborane-containing estrogenic agonists described here, having a new skeletal structure and unique characteristics, should yield novel therapeutic agents, especially selective estrogen receptor modulators. Furthermore, the suitability of the spherical carborane cage for binding to the cavity of the estrogen receptor-alpha ligand-binding domain should provide a basis for a similar approach to developing novel ligands for other steroid receptors.

Animals↗
PubMed2001

Activation of the lectin complement pathway by ficolins.

Mannose-binding lectin (MBL), a serum lectin specific for mannose or N-acetylglucosamine (GlcNAc), which contains both a collagen-like domain and a carbohydrate-recognition domain (CRD), plays a role in innate immunity by acting as an opsonin and activating complement in association with MBL-associated serine protease (MASP) via the lectin pathway. Another type of GlcNAc-binding lectins termed "ficolins" exist in serum. They are characterized by the presence of both a collagen-like domain and a fibrinogen-like domain. Investigations of two types of human serum ficolins, ficolin/P35 and Hakata antigen, revealed that they are associated with MASPs and sMAP, a truncated protein of MASP-2, and activate complement. These findings indicate that, like MBL, serum ficolins are collagenous lectins capable of activating the lectin pathway and thus have a role in innate immunity.

Carrier Proteins↗
PubMed2001

The human gene for mannan-binding lectin-associated serine protease-2 (MASP-2), the effector component of the lectin route of complement activation, is part of a tightly linked gene cluster on chromosome 1p36.2-3.

The proteases of the lectin pathway of complement activation, MASP-1 and MASP-2, are encoded by two separate genes. The MASP1 gene is located on chromosome 3q27, the MASP2 gene on chromosome 1p36.23-31. The genes for the classical complement activation pathway proteases, C1r and C1s, are linked on chromosome 12p13. We have shown that the MASP2 gene encodes two gene products, the 76 kDa MASP-2 serine protease and a plasma protein of 19 kDa, termed MAp19 or sMAP. Both gene products are components of the lectin pathway activation complex. We present the complete primary structure of the human MASP2 gene and the tight cluster that this locus forms with non-complement genes. A comparison of the MASP2 gene with the previously characterised C1s gene revealed identical positions of introns separating orthologous coding sequences, underlining the hypothesis that the C1s and MASP2 genes arose by exon shuffling from one ancestral gene.

Base Sequence↗
PubMed2001

Polymorphic expression of decay-accelerating factor in human colorectal cancer.

BACKGROUND: We have previously shown that expression of decay-accelerating factor (DAF), a complement regulatory protein, is enhanced immunohistochemically on the luminal surface of cancer glands in human colorectal cancer and is detected in stool specimens of patients with colorectal cancer. The amount of DAF present in the stools might be influenced by the stability of DAF on the cell surface which is regulated by biochemical properties such as glycosylation of the protein. In the present study, to help elucidate the mechanism for the release of DAF from human colorectal cancers, we biochemically analyzed DAF expression by western and northern blotting by using surgically resected specimens of colorectal cancers. METHODS: Surgically resected colorectal cancer tissues were obtained from 10 patients. Expression of DAF was determined by western and northern blotting, and glycosylation of DAF protein was analyzed with glycosidase digestion. RESULTS: Northern blot analysis demonstrated that the expression of DAF mRNA in colorectal cancer was enhanced two- to threefold compared with normal tissues. In western blotting, expression of DAF protein in the cancer tissue was increased, and heterogeneity in the apparent molecular weight of DAF was observed among patients. When o-linked sugars were removed, this heterogeneity of DAF size diminished. CONCLUSIONS: The polymorphic expression of DAF in colorectal cancer is likely to reflect variability in the o-glycosylation of the protein. We speculate that this variability could affect the stability of DAF on the surfaces of cancer cells and, in turn, the amount of DAF shed into the stools of colorectal cancer patients.

Adult↗
PubMed2001

Off-line leukapheresis using leukofiltration for active ulcerative colitis: a case report.

The method of leukocytapheresis for ulcerative colitis (UC) by using extracorporeal circulation (on-line system) has been reported. To perform leukocytapheresis, we have applied leukocyte elimination filters for blood transfusion to leukocytapheresis without using extracorporeal circulation (off-line leukocytapheresis system). Four hundred milliliters of peripheral blood was collected and reinfused through a leukocyte elimination filter. This procedure was repeated 5 times, and up to 2,000 ml of peripheral blood was treated. This method has been applied once a week for 5 weeks. We applied the off-line leukapheresis system to a 31-year-old male ulcerative colitis patient. As a result, the frequency of defecation and the dose of medicine were effectively decreased, and endoscopic finding was also improved. Because of the absence of complications observed with the on-line system, the off-line leukocytapheresis system that we have applied to the clinical patient is simple, safe, and useful.

Adult↗