Your browser doesn't support javascript.
loading
Montrer: 20 | 50 | 100
Résultats 1 - 20 de 150
Filtrer
1.
Endoscopy ; 44(6): 556-64, 2012 Jun.
Article de Anglais | MEDLINE | ID: mdl-22638778

RÉSUMÉ

BACKGROUND AND STUDY AIM: Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are being used increasingly to treat superficial oropharyngeal and hypopharyngeal carcinomas. The aim of this study was to clarify whether ESD provided better results than EMR for en bloc and complete resection of superficial pharyngeal carcinomas. PATIENTS AND METHODS: A total of 76 superficial pharyngeal carcinomas in 59 consecutively treated patients were included. Patients underwent either conventional EMR (using a transparent cap or strip biopsy) (n = 45 lesions) or ESD (n = 31 lesions) between October 2006 and January 2011. The rates of en bloc resection, complete resection (defined as en bloc resection with tumor-free margins), major complications, and local recurrence were evaluated retrospectively as the therapeutic outcomes. RESULTS: ESD yielded significantly higher rates of both en bloc and complete resection compared with EMR (en bloc 77.4 % [24/31] vs. 37.8 % [17/45], P = 0.0002; complete 54.8 % [17/31] vs. 28.9 % [13/45], P = 0.0379). ESD was more frequently complicated by severe laryngeal edema (4/21 [19.0 %] vs. 1/31 [3.2 %], P = 0.1446) and was also more time-consuming (124.9 ± 65.1 minutes vs. 57.2 ± 69.6 minutes; P = 0.0014). Local recurrence was observed more often after EMR than after ESD (3/45 [6.7 %] vs. 0/31 [0 %]), although this difference did not reach statistical significance (P = 0.2658). CONCLUSIONS: ESD appears to be a superior method of endoscopic resection of superficial pharyngeal carcinomas for achieving both en bloc and complete resection, although these benefits were also associated with a higher incidence of complications and a significantly longer procedure time. Large prospective studies are needed to compare ESD with conventional EMR for superficial pharyngeal carcinomas.


Sujet(s)
Carcinomes/chirurgie , Endoscopie digestive/méthodes , Muqueuse/chirurgie , Récidive tumorale locale/étiologie , Tumeurs du pharynx/chirurgie , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Carcinomes/anatomopathologie , Dissection/effets indésirables , Oedème/étiologie , Femelle , Humains , Estimation de Kaplan-Meier , Larynx , Durée du séjour , Mâle , Adulte d'âge moyen , Tumeurs du pharynx/anatomopathologie , Études rétrospectives , Statistique non paramétrique , Facteurs temps
2.
Endoscopy ; 44(2): 122-7, 2012 Feb.
Article de Anglais | MEDLINE | ID: mdl-22271022

RÉSUMÉ

BACKGROUND AND STUDY AIM: Endoscopic submucosal dissection (ESD) of undifferentiated-type early gastric cancer (UD-EGC) is technically feasible; however, the long-term clinical outcomes of the procedure have not yet been fully investigated. The aim of our study was to elucidate long-term outcomes of ESD for UD-EGC. PATIENTS AND METHODS: Between September 2003 and October 2009, a total of 153 patients were diagnosed endoscopically as having UD-EGC fulfilling the expanded criteria for ESD. After informed consent was obtained, 101 patients were selected to undergo ESD and 52 to undergo surgical operation. We assessed the clinical outcomes of ESD in 101 consecutive patients with 103 UD-EGC lesions who were undergoing ESD for the first time. The overall mortality and disease-free survival rates after ESD were evaluated as the long-term outcomes. RESULTS: The rates of en bloc and curative resection were 99.0% (102/103) and 82.5% (85/103), respectively. We encountered one patient with nodal metastasis detected by computed tomography before diagnostic ESD, although curative resection of the primary lesion was achieved based on routine histological examination. Among the 78 patients without a past history of malignancy within the previous 5 years in whom curative resection of the primary lesion was achieved, no cases of local recurrence or distant metastasis were observed during follow-up; however, 1 synchronous and 2 metachronous lesions were detected in 2 patients (2.6%) after primary ESD. Thus, estimated over a median follow-up period of 40.0 months (range 19-92 months) and 36.0 months (range 9-92 months), the 3-and 5-year overall mortality rates were 1.9% and 3.9%, respectively, and the 3-and 5-year overall disease-free survival rates were both 96.7%. CONCLUSIONS: Although our single-center retrospective study may be considered to be only preliminary, our data indicate that ESD for UD-EGC may yield good long-term outcomes.


Sujet(s)
Muqueuse gastrique/chirurgie , Gastroscopie/méthodes , Tumeurs de l'estomac/chirurgie , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Femelle , Études de suivi , Muqueuse gastrique/anatomopathologie , Humains , Mâle , Adulte d'âge moyen , Complications postopératoires , Études rétrospectives , Tumeurs de l'estomac/mortalité , Tumeurs de l'estomac/anatomopathologie , Analyse de survie , Taux de survie , Résultat thérapeutique
3.
J Microsc ; 234(2): 113-7, 2009 May.
Article de Anglais | MEDLINE | ID: mdl-19397739

RÉSUMÉ

The goal of specimen preparation for transmission electron microscopy is to obtain high-quality ultra-thin sections with which we can correlate cellular structure to physiological function. In this study, we newly developed a capsule-supporting ring that can be useful for resin embedding of glass-mounted specimens. The present device allowed us to re-embed a semi-thin section on a microscope slide into a resin block not only for efficient ultra-thin sectioning but also for a correlative light and electron microscopy. Similar to epoxy resins for morphological observations, semi-thin sections of low-viscosity hydrophilic resins, such as Lowicryl series, can be re-embedded into the resin, which can be useful for cytochemical gold labelling. A further application of the present device improved flat embedding of cultured cells on glass cover slips for electron microscopy, preserving in situ sub-cellular structures close to their native state. We practically describe the use of capsule-supporting ring and demonstrate representative micrographs as results.


Sujet(s)
Résines époxy/composition chimique , Microscopie électronique , Inclusion en plastique/instrumentation , Animaux , Muqueuse gastrique/ultrastructure , Cellules HeLa/ultrastructure , Humains , Immunohistochimie , Mâle , Cellules pariétales gastriques/ultrastructure , Rats , Rat Wistar
4.
Inflamm Res ; 51(1): 38-43, 2002 Jan.
Article de Anglais | MEDLINE | ID: mdl-11845997

RÉSUMÉ

OBJECTIVE: The effects of pretreatment with ONO-4007, a lipid A analog, on cutaneous plasma leakage induced by ONO-4007, lipopolysaccharide (LPS) and inflammatory mediators were investigated. MATERIAL: Male ddY strain mice. TREATMENT: Mice were pretreated with ONO-4007 (up to 6 mg/kg i.p.), 0-24 h prior to plasma leakage study. METHODS: Plasma extravasation was determined by dye leakage. RESULTS: Systemic ONO-4007 (6 mg/kg i. p.) pretreatment for 2 to 12 h inhibited plasma extravasation in the mouse skin elicited by ONO-4007 and LPS. The inhibition was dose-dependent. Plasma leakage induced by platelet-activating factor (PAF), histamine and 5-hydroxytryptamine (5-HT) was also inhibited by ONO-4007 pretreatment. Plasma corticosterone levels increased 2 and 4 h after systemic ONO-4007 (6 mg/kg) administration and returned to the control level 24 h later. Adrenalectomy and metyrapone but not propranolol reversed the inhibition by ONO-4007 pretreatment of LPS-induced plasma leakage. CONCLUSIONS: A single injection of ONO-4007 in mice induced transient tolerance to plasma leakage elicited by LPS, ONO-4007 and inflammatory mediators. Endogenous corticosterone, at least in part, plays a role in the development of tolerance.


Sujet(s)
Perméabilité capillaire/effets des médicaments et des substances chimiques , Lipide A/analogues et dérivés , Lipide A/pharmacologie , Glandes surrénales/physiologie , Animaux , Corticostérone/physiologie , Lipopolysaccharides/pharmacologie , Mâle , Métyrapone/pharmacologie , Souris
5.
Opt Lett ; 27(1): 46-8, 2002 Jan 01.
Article de Anglais | MEDLINE | ID: mdl-18007711

RÉSUMÉ

We have developed a 157-nm coherent light source by two-photon resonant four-wave mixing in Xe, with two tunable single-mode 1-kHz Ti:sapphire laser systems at 768 and 681 nm. This light source has been developed to determine the instrumental function of a vacuum ultraviolet spectrometer and to evaluate optical designs for ultra-line-narrowed F(2) laser lithography. The spectral linewidth of the source was less than 0.008 pm (FWHM), with an average power of 0.6 mW.

6.
Opt Lett ; 27(8): 637-9, 2002 Apr 15.
Article de Anglais | MEDLINE | ID: mdl-18007887

RÉSUMÉ

By use of KBe(2)BO(3)F(2) (KBBF) crystal with a size of 10 mmx10 mm x1.2 mm and a special prism-coupling technique (PCT), fourth-harmonic generation of Ti:sapphire laser systems from 200 to 179.4 nm has been achieved. Moreover, with a Ti:sapphire laser with a 50-fs pulse duration and a 1-kHz repetition rate, conversion efficiency as high as 13% from 400 to 200 nm without any surface-loss correction has also been obtained. The data show that with the PCT a KBBF crystal can produce deep-UV coherent light with measurable power output.

7.
Gastroenterology ; 121(6): 1460-72, 2001 Dec.
Article de Anglais | MEDLINE | ID: mdl-11729125

RÉSUMÉ

BACKGROUND & AIMS: Tissue recruitment of dendritic cells (DCs) is essential for antigen presentation. This study aimed to examine cellular and molecular mechanisms for DC recruitment to the liver. METHODS: Purified rat DCs were injected into circulation and their traffics were analyzed in normal and Kupffer cell-depleted rats by intravital confocal microscopy and immunohistology. Affinities of DCs to sinusoidal cells were examined by a cell-binding assay. DC precursor recruitment was induced by particulate injection. RESULTS: Both DC precursors and DCs at the antigen-transporting stage could be recruited to the liver, and their majority initially showed a selective binding to Kupffer cells. In the Kupffer cell-depleted rats, DCs could neither be recruited to the liver nor adhere to sinusoidal walls. Pretreatment with varied monosaccharides showed that sugar residues consisting of N-acetylgalactosamine were necessary for this binding. The binding was calcium-dependent, implying the C-type lectin involvement. Furthermore, DCs could endocytose N-acetylgalactosamine polymers in a receptor-specific manner. CONCLUSIONS: The DC-Kupffer cell binding through N-acetylgalactosamine-specific C-type lectin-like receptors is crucial for DC recruitment to the liver. Rat DCs at least partly possess receptors for endocytosis of galactosylated antigens. These DC receptors as well as Kupffer cell lectins are presumably responsible for this binding.


Sujet(s)
Acétyl-galactosamine/métabolisme , Métabolisme glucidique , Cellules dendritiques/physiologie , Cellules de Küpffer/physiologie , Foie/cytologie , Récepteurs de surface cellulaire/physiologie , Animaux , Mouvement cellulaire/physiologie , Phénomènes chimiques , Chimie physique , Cellules dendritiques/cytologie , Endocytose , Polymères/métabolisme , Rats , Lignées consanguines de rats , Récepteurs de surface cellulaire/métabolisme , Cellules souches/physiologie
8.
Histochem Cell Biol ; 116(4): 361-9, 2001 Oct.
Article de Anglais | MEDLINE | ID: mdl-11702194

RÉSUMÉ

High-pressure freezing/freeze substitution followed by Lowicryl K4M embedding provided an excellent morphology and antigenicity of the gastric glands, as well as the intraluminal fluid contents. Taking advantage of this, we histochemically investigated the secretory dynamics of the zymogenic contents in rat gastric gland, with special references to phospholipase A(2) (PLA(2)) and phospholipase Cgamma1 (PLCgamma1). The combination of immunogold labeling and KMnO4-uranyl acetate-lead citrate staining for zymogenic contents clearly demonstrated the rapid diffusion of PLA(2) molecules from the exocytosed zymogenic contents into the mucinous contents in gastric glandular lumens. In contrast, the exocytosed PLCgamma1 molecules remained within the zymogenic contents in the glandular lumens. These findings indicated the distinction between the exocytosed PLA(2) and PLCgamma1 in their diffusion rate. In addition, the mucinous contents surrounding the exocytosed zymogenic contents were intensely labeled with Griffonia simplicifolia II lectin which specifically recognizes the mucin of mucous neck cells. Interestingly, some of the PLA(2) immunolabeling on the mucinous contents was associated with the apical membranes of gastric epithelial cells, especially that of parietal cells. The secretory dynamics of the zymogenic contents in rat gastric glands, including their interaction with the mucinous contents are discussed.


Sujet(s)
Proenzymes/métabolisme , Muqueuse gastrique/métabolisme , Immunohistochimie/méthodes , Isoenzymes/métabolisme , Phospholipases A/métabolisme , Type C Phospholipases/métabolisme , Résines acryliques , Animaux , Exocytose , Congélation-dissolution , Congélation , Muqueuse gastrique/ultrastructure , Plomb , Mâle , Microscopie électronique/méthodes , Composés organométalliques , Phospholipase C gamma , Permanganate de potassium , Pression , Rats , Rat Wistar , Coloration et marquage/méthodes
9.
Histochem Cell Biol ; 115(5): 421-8, 2001 May.
Article de Anglais | MEDLINE | ID: mdl-11449890

RÉSUMÉ

A monoclonal antibody against insect CALNUC was shown to recognize an 85-kDa nuclear protein specifically in mammalian cells. Amino acid sequencing of the protein purified from rat liver revealed it to be EWS, a prooncoprotein for Ewing sarcomas and related tumors. Using the antibody, distribution of EWS was studied in rat tissues fixed with 4% paraformaldehyde by immunohistochemical methods. On thaw-fixed cryosections or those of perfusion-fixed tissues, almost all cell nuclei showed the specific staining. In immersion-fixed tissues, the staining unexpectedly disappeared in particular tissues (kidney cortex, liver, etc.), although it was recovered by autoclaving the cryosections. Western blotting also demonstrated the ubiquitous expression of EWS in the tissues. In extracts from the liver, the 85-kDa band rapidly disappeared in a Ca(2+)-dependent manner, but never in the testis. The antigen was very labile in kidney homogenates even without Ca2+. Biochemical studies with digoxigenin-labeled EWS showed that the Ca(2+)-dependent disappearance was associated with upward mobility shifts of EWS. These suggested that EWS was ubiquitously expressed in rat tissues, and that the antigen was masked in particular tissues during the immersion fixation.


Sujet(s)
Anticorps monoclonaux , Spécificité des anticorps/effets des médicaments et des substances chimiques , Protéines de liaison à l'ADN/immunologie , Substances de croissance/immunologie , Ribonucléoprotéines/analyse , Animaux , Calcium/pharmacologie , Protéines de liaison au calcium , Épitopes/analyse , Épitopes/effets des médicaments et des substances chimiques , Formaldéhyde/pharmacologie , Ribonucléoprotéines nucléaires hétérogènes , Humains , Immunohistochimie , Protéines d'insecte/immunologie , Mâle , Mammifères , Souris , Protéines de tissu nerveux , Nucléobindines , Spécificité d'organe , Protéine EWS de liaison à l'ARN , Rats , Rat Wistar , Ribonucléoprotéines/immunologie , Distribution tissulaire , Fixation tissulaire/méthodes , Cellules cancéreuses en culture
10.
Br J Pharmacol ; 133(2): 237-42, 2001 May.
Article de Anglais | MEDLINE | ID: mdl-11350859

RÉSUMÉ

Anti-inflammatory effects of cyclic AMP elevating agents were examined in a mouse model of lipopolysaccharide (LPS)-induced microvascular permeability change. Vascular permeability on the back skin was measured by the local accumulation of Pontamine sky blue (PSB) after subcutaneous injection of LPS (400 microg site-1) from Salmonella typhimurium. Dye leakage in the skin was significantly increased 2 h after injection of LPS. This LPS-induced dye leakage was suppressed by phosphodiesterase inhibitors, including pentoxifylline (160 mg kg-1), milrinone (5 - 10 mg kg-1), rolipram (0.5 - 10 mg kg-1) and zaprinast (5 - 10 mg kg-1). The dye leakage was also inhibited by beta-adrenoceptor agonists, including isoproterenol (0.5 - 5 mg kg-1) and salbutamol (0.05 - 5 mg kg-1), an adenylate cyclase activator, forskolin (5 mg kg-1), and a cell permeable cyclic AMP analogue, 8-bromo-cyclic AMP (8-Br-cAMP, 10 mg kg-1). LPS caused a transient increase in serum TNF-alpha level peaking at 1 h after the injection. This increase in serum TNF-alpha was completely blocked by a pretreatment with pentoxifylline (160 mg kg-1), milrinone (5 mg kg-1), rolipram (1 mg kg-1), zaprinast (10 mg kg-1), salbutamol (0.5 mg kg-1), forskolin (1 mg kg-1) and 8-Br-cAMP (10 mg kg-1). LPS caused an increase in serum IL-1alpha level peaking at 3 h after injection. This increase in serum IL-1alpha was not significantly suppressed by the cyclic AMP elevating agents. Our study suggests that cyclic AMP elevating agents attenuate LPS-induced microvascular permeability change by suppressing TNF-alpha up regulation.


Sujet(s)
Perméabilité capillaire/effets des médicaments et des substances chimiques , AMP cyclique/agonistes , Lipopolysaccharides/pharmacologie , Peau/métabolisme , 8-Bromo AMP cyclique/pharmacologie , Adenylate Cyclase/métabolisme , Agonistes bêta-adrénergiques/pharmacologie , Animaux , Anti-inflammatoires non stéroïdiens/pharmacologie , Colforsine/pharmacologie , AMP cyclique/analogues et dérivés , Activateurs d'enzymes/pharmacologie , Interleukine-1/métabolisme , Mâle , Souris , Inhibiteurs de la phosphodiestérase/pharmacologie , Salmonella typhimurium , Peau/effets des médicaments et des substances chimiques , Facteur de nécrose tumorale alpha/métabolisme
11.
Gastroenterology ; 120(4): 967-74, 2001 Mar.
Article de Anglais | MEDLINE | ID: mdl-11231950

RÉSUMÉ

BACKGROUND & AIMS: Wilson disease is a genetic disorder characterized by the accumulation of copper in the body as a result of a defect of copper excretion from hepatocytes. The intracellular localization of the Wilson disease gene product, ATP7B, was recently identified as the late endosomes. Various mutations have been documented in patients with Wilson disease. The clinical manifestations vary greatly among the patients; however, there is little information on the genotype-phenotype correlation. METHODS: We investigated the distribution of a common ATP7B mutant His1069Gln and a mutant Asp1270Ser by expressing the mutants tagged with green fluorescent protein in Huh7 and HEK293 cells. Intracellular organelles were visualized by fluorescence microscopy. RESULTS: Although the wild-type ATP7B and Asp1270Ser mutant localized in the late endosomes, His1069Gln mutant did not locate in the late endosomes and was degraded by the proteasomes in the cytoplasm. Furthermore, His1069Gln formed aggresomes composed of the degradates and intermediate filaments at the microtubule-organizing center. These aggresomes were similar to Mallory bodies on electron microscopy. CONCLUSIONS: The different protein properties of ATP7B mutants may explain the variety of clinical spectrums in patients with Wilson disease.


Sujet(s)
Acétylcystéine/analogues et dérivés , Adenosine triphosphatases/génétique , Protéines de transport/génétique , Transporteurs de cations , Cysteine endopeptidases/physiologie , Complexes multienzymatiques/physiologie , Mutation/physiologie , Acétylcystéine/pharmacologie , Adenosine triphosphatases/métabolisme , Protéines de transport/métabolisme , Lignée cellulaire , Copper-transporting ATPases , Cysteine endopeptidases/effets des médicaments et des substances chimiques , Cysteine endopeptidases/ultrastructure , Cytosquelette/ultrastructure , Technique d'immunofluorescence , Humains , Leupeptines/pharmacologie , Microscopie confocale , Microscopie électronique , Complexes multienzymatiques/effets des médicaments et des substances chimiques , Complexes multienzymatiques/ultrastructure , Proteasome endopeptidase complex , Distribution tissulaire
12.
Biochem Biophys Res Commun ; 281(2): 569-75, 2001 Feb 23.
Article de Anglais | MEDLINE | ID: mdl-11181085

RÉSUMÉ

The transcriptional coactivator p300, a histone acetyltransferase (HAT), plays key roles in the regulation of cell proliferation and differentiation. p300 is targeted by viral oncoproteins, and mutations of p300, accompanied by inactivation of the second allele, have been reported in certain types of cancers originating in the epithelium. Here, we identified a homozygous p300 deletion of exons 15--18 in the SiHa cervical carcinoma cell line, which results in an in-frame deletion that causes specific loss of the bromodomain, a conserved domain implicated in the regulation of HAT activity. Furthermore, we show that the mutation severely impaired its ability to activate the p21(WAF1/CIP1) promoter in transient reporter assay. These results suggest a critical role for the bromodomain in p300 functions as a tumor-suppressor gene.


Sujet(s)
Mutation , Protéines nucléaires/génétique , Transactivateurs/génétique , Tumeurs du col de l'utérus/génétique , Séquence nucléotidique , Sites de fixation/génétique , Technique de Western , Lignée cellulaire , Inhibiteur p21 de kinase cycline-dépendante , Cyclines/génétique , ADN complémentaire/génétique , Femelle , Régulation de l'expression des gènes tumoraux , Cellules HeLa , Humains , Cellules K562 , Luciferases/génétique , Luciferases/métabolisme , Protéines nucléaires/composition chimique , Protéines nucléaires/métabolisme , Régions promotrices (génétique)/génétique , Structure tertiaire des protéines , ARN messager/génétique , ARN messager/métabolisme , Protéines de fusion recombinantes/génétique , Protéines de fusion recombinantes/métabolisme , RT-PCR , Délétion de séquence , Transactivateurs/composition chimique , Transactivateurs/métabolisme , Cellules cancéreuses en culture , Cellules U937 , Tumeurs du col de l'utérus/métabolisme , Tumeurs du col de l'utérus/anatomopathologie
13.
J Biol Chem ; 276(13): 9742-8, 2001 Mar 30.
Article de Anglais | MEDLINE | ID: mdl-11133995

RÉSUMÉ

The mouse carcinoma cell line SX10 is a hypersensitive mutant to x-rays and bleomycin. An earlier complementation test suggests that SX10 would belong to x-ray-cross complementing group (XRCC) 4. However, in this study, a human XRCC4 expression vector failed to complement the SX10 phenotype. Consistent with the previous report, SX10 showed the same level of DNA-dependent protein kinase activity as the wild-type SR-1. We isolated and analyzed hybrids between SX10 and human diploid fibroblast cells and found that human chromosome 13 conferred the x-ray resistance to the hybrids, suggesting that a candidate gene would be located on this chromosome. Polymerase chain reaction analysis with these hybrids and x-ray-resistant transformants obtained by introducing human chromosomes into SX10 indicated that the mutant was likely to be defective in DNA ligase IV. Sequence analysis of the DNA ligase IV gene confirmed that a defect in SX10 was attributed to a transition of G to A at nucleotide position 1413 of the gene, leading to an amino acid substitution from Trp at residue 471 to a stop codon. Revertant clones (Rev1-3) derived from SX10 showed a restored x-ray resistance; Rev1 reverted to the original nucleotide G at position 1413, whereas Rev2 and Rev3 to C. Transfection of a mouse DNA ligase IV cDNA vector into SX10 restored the resistance to both x-rays and bleomycin. SX10 showed a reduced frequency of chromosomal integration of transfected DNA, but the revertants restored the frequency found in the wild-type cells. These results suggest a possible involvement of DNA ligase IV in the integration event of foreign DNA as well as a crucial role in DNA double-strand break repair.


Sujet(s)
DNA ligases/génétique , Mutation , Animaux , Bléomycine/pharmacologie , Technique de Southern , Chromosomes humains de la paire 13 , Codon , ADN/métabolisme , DNA ligase ATP , ADN complémentaire/métabolisme , Relation dose-effet des rayonnements , Électroporation , Vecteurs génétiques , Humains , Souris , Modèles génétiques , Phénotype , Mutation ponctuelle , Réaction de polymérisation en chaîne , Radiotolérance/génétique , RT-PCR , Analyse de séquence d'ADN , Transfection , Cellules cancéreuses en culture , Rayons X
14.
J Microsc ; 201(Pt 1): 77-83, 2001 Jan.
Article de Anglais | MEDLINE | ID: mdl-11136442

RÉSUMÉ

A simple contrast enhancement method is presented for Lowicryl K4M ultrathin sections prepared by high pressure freezing/freeze substitution. The sections were treated with an acidified potassium permanganate oxidizing solution followed by uranyl acetate and lead citrate staining. The method, designated KMnO4-UA/Pb staining, provided a much greater contrast in electron microscopy than conventional UA/Pb staining. In detail, the visibility of plasma membrane was especially improved and the nuclear heterochromatin, mitochondria and cytoplasmic ribosomes showed an adequate increase in electron density. In the mucous cells of rat Brunner's glands, the Golgi cisternae were well defined with the KMnO4-UA/Pb staining. Interestingly, the membranes of the intermediate compartments were moderately reactive to the KMnO4-UA/Pb staining, whereas the cis and the trans compartments were only faintly stained. It should be emphasized that the KMnO4 oxidation following colloidal gold labelling did not cause a remarkable reduction of immunogold labelling and the enhanced contrast helped us to examine the gold particles with high accuracy. This contrast enhancement method is highly promising, with the potential to become a useful tool for histochemical investigation, including immunocytochemistry with the Lowicryl K4M ultrathin sections prepared by high pressure freezing/freeze substitution techniques.


Sujet(s)
Résines acryliques , Histocytochimie/méthodes , Permanganate de potassium , Animaux , Acide citrique , Duodénum/ultrastructure , Microanalyse par sonde électronique , Cellules épithéliales/ultrastructure , Congélation , Amélioration d'image/méthodes , Jéjunum/ultrastructure , Plomb , Microscopie électronique , Composés organométalliques , Oxydoréduction , Pression , Rats , Rat Wistar , Coloration et marquage , Estomac/ultrastructure , Inclusion de tissu
15.
Biol Sci Space ; 15 Suppl: S64-6, 2001 Oct.
Article de Anglais | MEDLINE | ID: mdl-12101352

RÉSUMÉ

Several attempts have been made to investigate the effects of microgravity on the growth and function of animal cells. Cellular activation of immune T lymphocytes is greatly affected by microgravity. On the other hand, little is known about the effects of microgravity on B lymphocytes, another major class of immune lymphocytes, their growth or antibody production. Our approach to investigate the human B lymphocytes was to compare cell growth, nutrient consumption, and antibody secretion by a human B cell hybridoma between the cells cultured in space and the ground culture.


Sujet(s)
Production d'anticorps/physiologie , Lymphocytes B/métabolisme , Immunoglobuline M/biosynthèse , Vol spatial , Impesanteur , Ammoniac/métabolisme , Lymphocytes B/cytologie , Division cellulaire , Lignée cellulaire , Glutamine/métabolisme , Humains
16.
Endocrinology ; 141(11): 4255-61, 2000 Nov.
Article de Anglais | MEDLINE | ID: mdl-11089560

RÉSUMÉ

Ghrelin, a novel GH-releasing acylated peptide, was recently isolated from rat stomach. It stimulated the release of GH from the anterior pituitary through the GH secretagogue receptor (GHS-R). Ghrelin messenger RNA and the peptide are present in rat stomach, but its cellular source has yet to be determined. Using two different antibodies against the N- and C-terminal regions of rat ghrelin, we identified ghrelin-producing cells in the gastrointestinal tracts of rats and humans by light and electron microscopic immunohistochemistry and in situ hybridization combined with immunohistochemistry. Ghrelin-immunoreactive cells, which are not enterochromaffin-like cells, D cells, or enterochromaffin cells, accounted for about 20% of the endocrine cell population in rat and human oxyntic glands. Rat ghrelin was present in round, compact, electron-dense granules compatible with those of X/A-like cells whose hormonal product and physiological functions have not previously been clarified. The localization, population, and ultrastructural features of ghrelin-producing cells (Gr cells) indicate that they are X/A-like cells. Ghrelin also was found in enteric endocrine cells of rats and humans. Using two RIAs for the N- and C-terminal regions of ghrelin, we determined its content in the rat gastrointestinal tract. Rat ghrelin was present from the stomach to the colon, with the highest content being in the gastric fundus. Messenger RNAs of ghrelin and GHS-R also were found in these organs. Ghrelin probably functions not only in the control of GH secretion, but also in the regulation of diverse processes of the digestive system. Our findings provide clues to additional, as yet undefined, physiological functions of this novel gastrointestinal hormone.


Sujet(s)
Cellules entéroendocrines/métabolisme , Hormones peptidiques , Peptides/analyse , Animaux , Chromatographie en phase liquide à haute performance , Fundus gastrique/composition chimique , Ghréline , Humains , Immunohistochimie , Hybridation in situ , Gros intestin/composition chimique , Intestin grêle/composition chimique , Jéjunum/composition chimique , Mâle , Microscopie immunoélectronique , Peptides/génétique , ARN messager/analyse , Rats , Rat Wistar , RT-PCR
17.
J Vet Med Sci ; 62(8): 897-9, 2000 Aug.
Article de Anglais | MEDLINE | ID: mdl-10993189

RÉSUMÉ

With radiography and ultrasound, reversed positioning of the fundus ventriculi and pylorus, a duodenum running on the left side, transposition of the kidneys, and normal thoracic organs were found in a 5-month-old miniature dachshund that presented with anorexia and weight loss. The case was diagnosed as partial heterotaxia. Gross observation revealed partial heterotaxia, polysplenia, abnormal lobulation of the liver, and absence of the greater omentum. These findings were consistent with those observed in asplenia-polysplenia syndrome in humans.


Sujet(s)
Maladies des chiens/imagerie diagnostique , Situs inversus/médecine vétérinaire , Animaux , Chiens , Issue fatale , Femelle , Radiographie , Situs inversus/imagerie diagnostique , Échographie
18.
Eur J Morphol ; 38(4): 227-31, 2000 Oct.
Article de Anglais | MEDLINE | ID: mdl-10980672

RÉSUMÉ

The fine structure of tuft cells in the main excretory duct of rat submandibular gland was investigated using the high pressure freezing and freeze substitution (HPF-FS) method and compared with that seen with both conventional chemical fixation (CF) method and en bloc treatment with ruthenium red. Some MEDs also were subjected to histochemistry for lectins. The apical vesicles and tubules of tuft cells observed by TEM after the HPF-FS method were different in shape from those treated by CF. With the first method, these vesicles and tubules, which may represent sections of a tubular system, appeared more slender and filled with a material of moderate density. A prominent glycocalyx covering the microvillar plasma membrane was observed in tuft cells processed both with the HPF-FS method and with ruthenium red. The surface of microvilli and the tubulo-vesicular structures of these cells exhibited the same soybean agglutinin (SBA) reactivity, suggesting a relationship between them.


Sujet(s)
Glande submandibulaire/ultrastructure , Animaux , Mâle , Microscopie électronique , Rats , Rat Wistar , Fixation tissulaire/méthodes
19.
J Agric Food Chem ; 48(8): 3448-54, 2000 Aug.
Article de Anglais | MEDLINE | ID: mdl-10956132

RÉSUMÉ

The cell wall materials (CWMs) from sweetpotato (Ipomoea batatas cv. Kokei 14), cassava (Manihot esculenta), and potato (Solanum tuberosum cv. Danshaku) and commercial sweetpotato fiber as well as their polysaccharide fractions were analyzed for sugar composition by the high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) method. The separation of arabinose and rhamnose, and xylose and mannose, by this method has been improved using a CarboPac PA 10 column. Pretreatment of the CWMs and cellulose fractions with 12 M H(2)SO(4) was required for complete hydrolysis to occur. Commercial sweetpotato fiber was found to be mainly composed of glucose (88.4%), but small amounts of other sugars were also detected. Among the root crops, sweetpotato CWM had the highest amount of pectin and galacturonic acid. Fucose was detected only in cassava CWM and its hemicellulose fraction, while galactose was present in the highest amount in potato CWM. Among the polysaccharide fractions, it was only in the hemicellulose fraction where significant differences in the sugar composition, especially in the galactose content, were observed among the root crops.


Sujet(s)
Chromatographie en phase liquide à haute performance/méthodes , Chromatographie d'échange d'ions/méthodes , Oses/analyse , Polyosides/composition chimique , Solanaceae/composition chimique , Résines échangeuses d'anions , Paroi cellulaire/composition chimique , Fibre alimentaire/analyse , Électrochimie
20.
Eur J Cell Biol ; 79(3): 208-17, 2000 Mar.
Article de Anglais | MEDLINE | ID: mdl-10777113

RÉSUMÉ

A mouse monoclonal antibody 12B1 was raised against Golgi fractions from Sf21 insect cells and selected as Golgi-specific by immunostaining of the cells. The antigen was purified from the cells by immunoaffinity chromatography with the monoclonal antibody, and its N-terminal and internal amino acid sequences were determined. Based on the partial amino acid sequences, cDNA encoding the antigen protein was cloned and sequenced. The amino acid sequence deduced from the cDNA nucleotide sequence showed a homology to those of CALNUC family proteins, CALNUC (or nucleobindin, a calcium-binding Golgi protein with DNA-binding activity) and protein NEFA (a cell surface protein with DNA-binding, EF-hand, and acidic domains). The insect protein had two EF-hand loops at the same sites as the mammalian CALNUC family proteins, but had no leucine zipper which the mammalian homologues commonly have. An electron microscopic immunoperoxidase study demonstrated that the insect protein was localized in the cis-Golgi cisternae and cis-Golgi networks. Since this localization is identical to that of mammalian CALNUC, the insect protein was considered to be a homologue of CALNUC rather than that of NEFA. Assays involving proteinase K digestion, sodium carbonate extraction and Triton X-114 extraction revealed that the insect CALNUC-like protein was a soluble protein tightly associated with the luminal surface of Golgi membranes as reported for mammalian CALNUC. The insect protein was also shown to have calcium-binding activity as does mammalian CALNUC. These data verify that the insect protein is CALNUC. The existence of CALNUC in insect cells suggests that CALNUC is an essential calcium-binding Golgi protein in a wide range of the animal kingdom. A phylogenetic tree analysis, however, suggested that NEFA was derived from CALNUC long after the segregation of a mammalian ancestor from an insect ancestor.


Sujet(s)
Protéines de liaison à l'ADN/biosynthèse , Appareil de Golgi/métabolisme , Substances de croissance/biosynthèse , Acetylglucosaminidase/métabolisme , Séquence d'acides aminés , Animaux , Anticorps monoclonaux/métabolisme , Technique de Western , Calcium/métabolisme , Protéines de liaison au calcium , Lignée cellulaire , Centrifugation en gradient de densité , ADN complémentaire/métabolisme , Femelle , Technique d'immunofluorescence , Immunoglobuline G/métabolisme , Immunohistochimie , Insectes , Mannosidases/métabolisme , Souris , Souris de lignée BALB C , Microscopie électronique , Données de séquences moléculaires , Protéines de tissu nerveux , Nucléobindines , Phylogenèse , Liaison aux protéines , Similitude de séquences d'acides aminés , alpha-Mannosidase
SÉLECTION CITATIONS
DÉTAIL DE RECHERCHE
...