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1.
Br J Cancer ; 107(9): 1595-601, 2012 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-22968650

RESUMO

BACKGROUND: There is a need for sensitive and specific blood-borne markers for the detection of gastric cancer. Raised serum macrophage inhibitory factor (MIF) levels have been proposed as a marker for gastric cancer diagnosis but, to date, studies have only encompassed patients from high-incidence areas. METHODS: We have compared the serum concentration of MIF in a large cohort of UK and Japanese gastric cancer patients, together with appropriate control subjects (age and gender matched). Carcinoembryonic antigen and H. pylori IgG were also measured, as was DJ-1, a novel candidate protein biomarker identified by analysis of gastric cancer cell line secretomes. RESULTS: Marked elevations of the serum concentration of MIF and DJ-1 were seen in Japanese patients with gastric cancer compared with Japanese controls, a trend not seen in the UK cohort. These results could not be accounted for by differences in age, disease stage or H. pylori status. CONCLUSION: In regions of high, but not low incidence of gastric cancer, both MIF and DJ-1 have elevated serum concentrations in gastric cancer patients, compared with controls. This suggests that differing mechanisms of disease pathogenesis may be at play in high- and low-incidence regions.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/sangue , Fatores Inibidores da Migração de Macrófagos/sangue , Proteínas Oncogênicas/sangue , Neoplasias Gástricas/sangue , Neoplasias Gástricas/epidemiologia , Estudos de Coortes , Feminino , Humanos , Incidência , Japão/epidemiologia , Masculino , Estudos Prospectivos , Proteína Desglicase DJ-1 , Reino Unido/epidemiologia
2.
Br J Cancer ; 101(2): 295-302, 2009 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-19550422

RESUMO

BACKGROUND: Proteomic methods have the potential to meet the urgent need for better cancer biomarkers. We have used a range of proteomic analyses of serum and tissue from gastric cancer patients and relevant controls to discover biomarkers for gastric cancer. METHODS: Surface-enhanced laser desorption/ionisation time-of-flight mass spectrometry (SELDI) and antibody arrays were used to compare protein expression in 21 pairs of gastric cancer tissue and adjacent normal mucosa and serum from 51 gastric cancer patients and 29 patients with benign gastric diseases. Expression differences were confirmed by enzyme-linked immunosorbent assay. RESULTS: Tissue analysis shows human neutrophil peptides 1-3 (HNPs 1-3) elevated 10-fold (P=0.001) in gastric cancer relative to adjacent normal mucosa. Macrophage migration inhibitory factor (MIF) was increased five-fold (P=1.84 x 10(-7)) in the serum of gastric cancer patients relative to individuals with benign gastric disease. The large increase in MIF concentration in serum gives an area under the receiver operating characteristic curve of 0.85. CONCLUSIONS: Proteomic analyses of serum and tissue indicate that HNPs 1-3 and MIF have potential as biomarkers for gastric cancer. In particular MIF may be useful, either alone or in combination with other markers, for diagnosing and monitoring gastric cancer.


Assuntos
Biomarcadores Tumorais/biossíntese , Fatores Inibidores da Migração de Macrófagos/biossíntese , Neoplasias Gástricas/metabolismo , alfa-Defensinas/biossíntese , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/sangue , Proteínas Sanguíneas/análise , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Fatores Inibidores da Migração de Macrófagos/sangue , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/sangue , Estadiamento de Neoplasias , Análise Serial de Proteínas , Proteômica/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Neoplasias Gástricas/sangue , Neoplasias Gástricas/patologia , alfa-Defensinas/sangue
3.
Plant Cell Rep ; 22(4): 239-43, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14586550

RESUMO

This report describes the successful plant regeneration via somatic embryogenesis from immature zygotic embryos of Cryptomeria japonica D. Don. For the induction of embryogenic tissue, we determined that the optimal medium contained N6-benzyladenine and 2,4-dichlorophenoxyacetic acid. Immature zygotic embryos that were collected at the end of June yielded embryogenic tissue at the highest frequency. Embryogenic tissues that had proliferated in liquid medium included small and loosely packed cells and elongating or elongated cells. We used ten cell lines to determine the optimal medium for the development of somatic embryos. Induced somatic embryos germinated with synchronous sprouting of cotyledons, hypocotyls and roots. Gibberellin A3 in the germination medium had a positive effect on both the elongation of hypocotyls and the survival of seedlings. The frequencies of induction and germination of somatic embryos differed among the cell lines examined. Most of the seedlings grew normally. This system of somatic embryogenesis required 4-5 months for the regeneration of C. japonica plantlets from immature zygotic embryos.


Assuntos
Cryptomeria/embriologia , Sementes/crescimento & desenvolvimento , Regeneração
4.
J Neurochem ; 79(1): 45-54, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11595756

RESUMO

Prominent neurite outgrowth induced by genipin, a plant-derived iridoid, was substantially inhibited by addition of NG-nitro-L-arginine methyl ester (L-NAME), a nitric oxide (NO) synthase (NOS) inhibitor, and carboxy-PTIO, an NO scavenger, in PC12h cells. Increases of the NADPH-diaphorase activity and neuronal and inducible NOS proteins in cells preceded the neurite outgrowth after addition of genipin to medium. NO donors could induce the neurite outgrowth dose-dependently in the cells. On the other hand, an inhibitor of soluble guanylate cyclase (SGC), which is known to be a stimulatory target of NO, abolished greatly the genipin-induced neurite outgrowth. Addition of extracellular signal-regulated kinase (ERK) kinase inhibitors could almost completely abolish the neurite induction. L-NAME remarkably depressed genipin-stimulated phosphorylation of ERK-1 and -2. A neuritogenic effect of nerve growth factor (NGF) in PC12h cells was also remarkably inhibited by the NOS inhibitor, NO scavenger and SGC inhibitor. These findings suggest that induced NO production followed by cyclic GMP-mediated stimulation of the mitogen-activated protein kinase (MAPK) cascade is implicated in the neuritogenesis by genipin and NGF in PC12h cells.


Assuntos
Proteínas Quinases Ativadas por Mitógeno/metabolismo , Neuritos/efeitos dos fármacos , Óxido Nítrico/biossíntese , Células PC12/ultraestrutura , Piranos/farmacologia , Animais , Ativação Enzimática/efeitos dos fármacos , Indução Enzimática , Inibidores Enzimáticos/farmacologia , Sequestradores de Radicais Livres , Guanilato Ciclase/antagonistas & inibidores , Glicosídeos Iridoides , Iridoides , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , NG-Nitroarginina Metil Éster/farmacologia , Fator de Crescimento Neural/farmacologia , Neuritos/ultraestrutura , Óxido Nítrico/fisiologia , Doadores de Óxido Nítrico/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/biossíntese , Óxido Nítrico Sintase Tipo I , Óxido Nítrico Sintase Tipo II , Óxido Nítrico Sintase Tipo III , Células PC12/enzimologia , Fosforilação , Ratos
5.
Cell Calcium ; 29(5): 311-25, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11292388

RESUMO

Repetitive Ca(2+) release from the endoplasmic reticulum (ER) is necessary for activation of mammalian eggs. Influx and release of Mn(2+) and Ca(2+) during Ca(2+) oscillations induced by injection of sperm extract (SE) into mouse eggs were investigated by Mn(2+)-quenching of intracellular Fura-2 after adding Mn(2+) to external medium. Mn(2+)/Ca(2+) influx was detected at the resting state. A marked Mn(2+)/Ca(2+) influx occurred during the first Ca(2+) release upon SE injection, and persistently facilitated Mn(2+)/Ca(2+) influx was observed during steady Ca(2+) oscillations. As intracellular Mn(2+) concentration ([Mn(2+)](i)) increased progressively, periodic [Mn(2+)](i) rises appeared, corresponding to each Ca(2+)transient but taking a slower time course. A numerical simulation based on continuous Mn(2+)/Ca(2+) influx-extrusion across the plasma membrane and release-uptake across the ER membrane in a competitive manner mimicked well the Mn(2+) oscillations calculated from experimental data, strongly suggesting that repetitive Mn(2+) release develops after Mn(2+) entry and uptake into the ER. In other experiments, a marked Mn(2+) influx occurred upon Mn(2+) addition to Ca(2+)-free medium after depletion of the ER using an ER Ca(2+) pump inhibitor plus repeated injection of inositol 1,4,5-trisphosphate (InsP(3)). No significant increase in Mn(2+) influx was induced by injection of SE, InsP(3), or Ca(2+), when Ca(2+) release was prevented by pre-injection of an antibody against the InsP(3) receptor. We concluded that Ca(2+) influx is activated during the initial large Ca(2+)release possibly by a capacitative mechanism and kept facilitated during steady Ca(2+) oscillations. The finding that repetitive Mn(2+) release is caused by continuous Mn(2+) entry suggests that continuous Ca(2+) influx may play a critical role in refilling the ER and, thereby, maintaining Ca(2+)oscillations in mammalian fertilization.


Assuntos
Cálcio/metabolismo , Manganês/metabolismo , Interações Espermatozoide-Óvulo/fisiologia , Animais , Cátions Bivalentes , Extratos Celulares , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Óvulo/metabolismo , Óvulo/fisiologia , Espermatozoides/fisiologia
6.
Biol Pharm Bull ; 24(12): 1434-6, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11767118

RESUMO

Polyacetylenic alcohols and their linoleates isolated from Panax ginseng C. A. MEYER and Cirsium japonicum DC., of which the lipophilic extracts had been found to affect the neuritogenesis of cultured paraneurons, were demonstrated to have a significant neuritogenic effect on PC12h and Neuro2a cells. Panaxynol and the acetylenic triol in particular were highly efficient at concentrations > or = 2 microm. Panaxynol (20 mg/kg/d, i.p., for 3 d) was confirmed to improve scopolamine-induced memory deficit in mice (Y-maze task). It is suggested that the promotion of neuritogenesis in cultured paraneurons by the addition of panaxynol is related its ability to improve memory deficits in animals.


Assuntos
Acetileno/análogos & derivados , Acetileno/farmacologia , Acetileno/uso terapêutico , Transtornos da Memória/tratamento farmacológico , Neuritos/efeitos dos fármacos , Polímeros/farmacologia , Polímeros/uso terapêutico , Escopolamina/toxicidade , Acetileno/isolamento & purificação , Animais , Masculino , Transtornos da Memória/induzido quimicamente , Camundongos , Antagonistas Muscarínicos/toxicidade , Neuritos/fisiologia , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Células PC12 , Panax , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Raízes de Plantas , Polímeros/isolamento & purificação , Poli-Inos , Ratos
7.
Biol Pharm Bull ; 24(12): 1454-5, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11767124

RESUMO

Genipin, which was shown in our previous investigation to have prominent neuritogenic activity in paraneurons such as PC12h cells, was studied to determine whether it could prevent the toxicity of Alzheimer's amyloid beta protein (Abeta) in cultured hippocampal neurons. Increased release of lactate dehydrogenase from hippocampal neurons after 2 d of Abeta25-35 administration was prevented dose dependently by the addition of genipin 20-40 microm. Morphological observations and trypan blue staining of cells confirmed the protection of hippocampal neurons from Abeta toxicity by genipin. Geniposide had less effect in preventing Abeta toxicity.


Assuntos
Peptídeos beta-Amiloides/antagonistas & inibidores , Peptídeos beta-Amiloides/toxicidade , Fator de Crescimento Neural/farmacologia , Piranos/farmacologia , Animais , Células Cultivadas , Colagogos e Coleréticos/farmacologia , Colagogos e Coleréticos/uso terapêutico , Relação Dose-Resposta a Droga , Embrião de Mamíferos , Hipocampo/citologia , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Glicosídeos Iridoides , Iridoides , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/patologia , Ratos
8.
Planta Med ; 66(6): 575-7, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10985091

RESUMO

The MeOH extract of Epimedium sagittatum was found to show neurite outgrowth activity on cultured PC12h cells. Bioassay-guided fractionation of the MeOH extract yielded six prenylated flavonol glycosides, ikarisoside A (1), icarisid II (2), epimedoside A (3), icariin (4), epimedin B (5), and epimedokoreanoside-I (6) as the active ingredients.


Assuntos
Flavonoides/farmacologia , Glicosídeos/farmacologia , Neuritos/efeitos dos fármacos , Plantas Medicinais/química , Animais , Células PC12 , Ratos
9.
Surg Endosc ; 14(9): 787-90, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11000355

RESUMO

BACKGROUND: Reports suggest that the insufflation of cold gas to produce a pneumoperitoneum for laparoscopic surgery can lead to an intraoperative decrease in core body temperature and increased postoperative pain. METHODS: In a randomized controlled trial with 20 patients undergoing laparoscopic cholecystectomy, the effect of insufflation using carbon dioxide gas warmed to 37 degrees C (group W) was compared with insufflation using room-temperature cold (21 degrees C) gas (group C). Intraoperative body core and intra-abdominal temperatures were determined at the beginning and end of surgery. Postoperative pain intensity was evaluated using a visual analog scale and recording the consumption of analgesics. RESULTS: There were no significant group-specific differences during the operation, neither in body temperature (group W: 36.1 +/- 0.4 degrees C vs group C: 35.7 +/- 0.6 degrees C) nor in intra-abdominal temperature (group W: 35.9 +/- 0.3 degrees C vs group C: 35.6 +/- 0. 6 degrees C). Postoperatively, the two groups did not differ in pain susceptibility and need of analgesics. CONCLUSION: The use of carbon dioxide gas warmed to body temperature to produce a pneumoperitoneum during short-term laparoscopic surgery has no clinically important effect.


Assuntos
Dióxido de Carbono , Colecistectomia Laparoscópica , Pneumoperitônio Artificial/métodos , Temperatura , Idoso , Colelitíase/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor Pós-Operatória/prevenção & controle , Estudos Prospectivos
10.
Jpn J Pharmacol ; 82(4): 301-6, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10875749

RESUMO

Neurotoxicity of beta42 (20 microM) in cultured rat hippocampal neurons was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction and lactate dehydrogenase (LDH) release methods as quantitative assays of cell death, and both methods indicated that propentofylline (PPF) had the ability to protect the neurons against the toxicity, although these two assay methods revealed different mechanisms for the toxic effect of beta42. Promotion of the active exocytotic system of the cells was suggested after treatment with beta42 in the MTT assay and in determination of 9-aminoacridine (AA) excretion from the preloaded cells after 24-h treatment with beta42. The promotion of AA exocytosis was blocked by the addition of PPF (20 microg/ml). The preventive effect of PPF on the neurotoxicity of beta42 has been proposed to be caused by elevation of the intracellular level of cAMP as a result of depression of the hydrolytic activity of cells.


Assuntos
Peptídeos beta-Amiloides/toxicidade , Hipocampo/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Fragmentos de Peptídeos/toxicidade , Xantinas/farmacologia , Peptídeos beta-Amiloides/antagonistas & inibidores , Animais , Morte Celular/efeitos dos fármacos , Células Cultivadas , AMP Cíclico/metabolismo , Interações Medicamentosas , Exocitose/efeitos dos fármacos , Hipocampo/citologia , Hipocampo/fisiologia , L-Lactato Desidrogenase/metabolismo , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Fragmentos de Peptídeos/antagonistas & inibidores , Ratos , Ratos Wistar , Sais de Tetrazólio/metabolismo , Tiazóis/metabolismo
11.
Dev Biol ; 218(2): 299-313, 2000 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-10656771

RESUMO

Fertilized mouse eggs exhibit repetitive rises in intracellular Ca(2+) concentration ([Ca(2+)](i)) necessary for egg activation. Precise spatiotemporal dynamics of each [Ca(2+)](i) rise were investigated by high-speed Ca(2+) imaging during early development of monospermic eggs. Every [Ca(2+)](i) rise involved a Ca(2+) wave. In the first Ca(2+) transient, [Ca(2+)](i) increased in two steps separated by a "shoulder" point, suggesting two distinct Ca(2+) release mechanisms. The first step was a Ca(2+) wave that propagated from the sperm-fusion site to its antipode in 4-5 s (velocity, approximately 20 microm/s in most eggs). The second step from the shoulder to the peak was a nearly uniform [Ca(2+)](i) rise of 12-15 s. A slight cytoplasmic movement followed the Ca(2+) wave in the same direction and recovered in 25-35 s. These characteristics changed as follows, as Ca(2+) oscillations progressed during the second meiosis up to their cessation at the stage of pronuclei formation ( approximately 3 h after fertilization). (1) The duration of Ca(2+) transients became shorter. (2) The shoulder point shifted to higher levels and the first step occupied most of the rising phase. (3) The rate of [Ca(2+)](i) rise became greater and wave speeds increased up to 80-100 microm/s or more. (4) The transient cytoplasmic movement always resulted from the Ca(2+) wave, although its displacement became smaller. (5) The Ca(2+) wave initiation site was freed from the sperm-fusion or -entry site and eventually localized in the cortex of the vegetal hemisphere. Since the shift of the wave initiation site to the vegetal cortex is observed in fertilized eggs of nemertean worms and ascidians, this might be an evolutionarily conserved feature.


Assuntos
Cálcio/metabolismo , Interações Espermatozoide-Óvulo , Animais , Citoplasma/metabolismo , Feminino , Fertilização , Cinética , Masculino , Camundongos , Espermatozoides/fisiologia
12.
Plant Cell Rep ; 19(5): 448-453, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30754881

RESUMO

ROBINIA PSEUDOACACIA: (black locust) plants were regenerated after co-cultivation of stem and leaf segments with Agrobacterium tumefaciens strain GV3101 (pMP90) that harbored a binary vector that included genes for ß-glucuronidase (GUS) and hygromycin phosphotransferase. Successful transformation was confirmed by the ability of stem and leaf segments to produce calli in the presence of hygromycin, by histochemical and fluorometric assays of GUS activity in plant tissues, and by Southern blotting analysis. In this transformation system, about 2 months were required for regeneration of transgenic plants from stem and leaf segments. The frequency of transformation from stem segments was approximately 24%, and the morphology of regenerated plants resembled that of the original parental strain.

13.
Exp Cell Res ; 253(2): 533-40, 1999 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-10585277

RESUMO

Functions of small GTPases in integrin expression were investigated when the interaction of nonadherent human colon carcinoma 201 cells with the extracellular matrix (ECM) was examined. By transfection of the constitutively active form of a small GTPase Rac1, Rac V12, adhesion of cells to the ECM increased with concomitant cell spreading and formation of membrane ruffles. Activated Cdc42 and Cdc42 V12, but not wild-type Rac1, Cdc42, or RhoA, also induced the adhesion and spreading of Colo201 cells. This adhesion is integrin beta4 dependent since an antibody for integrin beta4 inhibited the RacV12-dependent cell adhesion and numbers of adhesive cells on laminin-coated plates exceeded those on collagen- and fibronectin-coated plates. By immunofluorescence, in addition to clustering of integrin molecules, expression of integrin alpha6beta4 on the cell surface of Rac V12- and Cdc42 V12-expressing cells was selectively up-regulated without an increase in biosynthesis of alpha6beta4 integrin. Treatment of Rac V12-expressing cells with wortmannin or LY294002, specific inhibitors of phosphoinositide 3-OH kinase, decreased the up-regulated alpha6beta4 and cell adhesion. In light of this evidence, we propose that the regulation of integrin alpha6beta4 expression induced by Rac1 and Cdc42 may play an important role in cell adhesion and tumorigenesis of colon carcinoma cells.


Assuntos
Antígenos de Superfície/genética , Antígenos de Superfície/metabolismo , Neoplasias do Colo , Integrinas/genética , Integrinas/metabolismo , Proteínas rac1 de Ligação ao GTP/genética , Proteínas rac1 de Ligação ao GTP/metabolismo , Anticorpos Monoclonais/farmacologia , Antígenos de Superfície/imunologia , Adesão Celular/fisiologia , Membrana Celular/fisiologia , Tamanho Celular/fisiologia , Citometria de Fluxo , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Integrina alfa6beta4 , Integrinas/imunologia , Laminina , Fosfatidilinositol 3-Quinases/metabolismo , Transfecção , Células Tumorais Cultivadas/citologia , Células Tumorais Cultivadas/enzimologia , Regulação para Cima/fisiologia , Proteína cdc42 de Ligação ao GTP/genética , Proteína cdc42 de Ligação ao GTP/metabolismo
14.
Dev Biol ; 209(1): 172-85, 1999 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-10208751

RESUMO

Hamster sperm extract (SE) possessing Ca2+ oscillation-inducing activity was microinjected into the peripheral or central region of mouse eggs, and the first increase in intracellular Ca2+ concentration ([Ca2+]i), together with the spread of fluorescence-labeled SE in the ooplasm, was investigated by imaging with confocal microscopy. Injection into the periphery always induced a Ca2+ wave that started from the injection site after a delay of 5 to 30 s depending on the concentration of SE. The diluted SE caused a wave of two-step [Ca2+]i rises, which was always observed at fertilization. Injection into the center could induce a radial Ca2+ wave with relatively high dose of SE, but lower dose of SE caused a [Ca2+]i rise after a longer delay which was initiated synchronously over the ooplasm or was preceded in a peripheral area. Injection of diluted SE remarkably prolonged the delay time and reduced the rate of [Ca2+]i rise. The critical concentration of SE needed to induce [Ca2+]i rise was significantly lower in the periphery. These results indicate that the sensitivity to SE is higher in the cortex. SE-induced [Ca2+]i rises were blocked by an antibody against the type 1 inositol 1,4,5-trisphosphate receptor (InsP3R). The cortex was substantially more sensitive to injected InsP3 induction of Ca2+ release than the center. It is suggested that the cortex of mouse eggs may involve a functionally specialized organization of InsP3Rs and Ca2+ pools in which a cytosolic sperm factor(s) could act upon sperm-egg fusion to cause Ca2+ release, leading to the Ca2+ wave at fertilization.


Assuntos
Canais de Cálcio/metabolismo , Cálcio/metabolismo , Óvulo/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Espermatozoides/metabolismo , Animais , Canais de Cálcio/imunologia , Sinalização do Cálcio , Cricetinae , Relação Dose-Resposta a Droga , Feminino , Fertilização/fisiologia , Receptores de Inositol 1,4,5-Trifosfato , Fosfatos de Inositol/metabolismo , Masculino , Camundongos , Microscopia de Fluorescência , Receptores Citoplasmáticos e Nucleares/imunologia , Fatores de Tempo
15.
Gene ; 227(2): 117-24, 1999 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-10023040

RESUMO

Ferrochelatase (EC.4.99.1.1), the final step in the biosynthesis of heme, is widely expressed in various tissues and is induced in erythroid cells. We determined the structure of the mouse ferrochelatase gene after isolation and characterization of lambda phage clones mapping discrete regions of the cDNA. The gene spans about 25 kb and consists of 11 exons. The exon/intron boundary sequences conform to consensus acceptor (GTn)/donor (nAG) sequences, and exons in the gene encode functional protein domains. The promoter region contains multiple Sp1 sites, a CACCC box and GATA-1 binding sites. Function analysis of the promoter by transient transfection assay demonstrated that one Sp1 binding site located at -37/-32 is essential for basic expression of the ferrochelatase gene in both mouse erythroleukemia (MEL) and non-erythroid EL4 cells. In addition, the region (-66/-51) containing a CACCC box and the neighboring GC box partly contributes to the inducible activity of the reporter in MEL cells upon induction with dimethylsulfoxide. It appears that at least two promoter regions of the mouse ferrochelatase gene function in basic and inducible expression.


Assuntos
Ferroquelatase/genética , Regulação da Expressão Gênica/genética , Transcrição Gênica/genética , Animais , Sequência de Bases , Clonagem Molecular , Proteínas de Ligação a DNA/genética , Éxons/genética , Genes Reporter/genética , Íntrons/genética , Camundongos , Dados de Sequência Molecular , Regiões Promotoras Genéticas/genética , Análise de Sequência de DNA , Deleção de Sequência/genética , Fator de Transcrição Sp1/genética , Transfecção/genética , Células Tumorais Cultivadas
16.
Cell Calcium ; 26(1-2): 49-58, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10892570

RESUMO

Intracytoplasmic sperm injection (ICSI) into mammalian eggs induces repetitive rises in intracellular Ca2+ concentration ([Ca2+]i) which are the pivotal signal in fertilization. Spatiotemporal aspects of [Ca2+]i rises following ICSI into the periphery of mouse eggs were investigated with high-speed confocal microscopy. The first Ca2+ response was generated 25-30 min after ICSI, when [Ca2+]i increased slowly and reached a certain level. The [Ca2+]i rise occurred synchronously over the ooplasm, attained the peak in 40-70 s, and lasted for 5-7 min. Succeeding Ca2+ responses occurred at intervals of 20-30 min, associated with the faster rate of [Ca2+]i rise and the shorter duration as Ca2+ oscillations progressed. The [Ca2+]i rises took the form of a wave that started from an arbitrary cortical region, but not from the vicinity of the injected sperm head. The Ca2+ wave became more pronounced and propagated across the egg faster in the later Ca2+ responses. An artifactual [Ca2+]i rise was inevitably produced during the ICSI procedure. The larger artifact affected the subsequent first Ca2+ response, resulting in the faster [Ca2+]i rise (time to peak, 10-20 s), slight spatial heterogeneity of [Ca2+]i rise in the ooplasm (but not a wave) and the shorter duration (3-4 min). The artifact slightly affected the amplitude of the second Ca2+ response, but little affected the later Ca2+ responses. It is suggested that the factor(s) that leaked out of the injected spermatozoon diffuses to a wide area and sensitizes Ca2+ channels of the endoplasmic reticulum to induce Ca2+ release synchronously over the ooplasm. The enhanced sensitization leads to propagating Ca2+ release initiated from the cortex that is more sensitive to the sperm factor.


Assuntos
Cálcio/metabolismo , Oócitos/fisiologia , Injeções de Esperma Intracitoplásmicas , Animais , Canais de Cálcio/metabolismo , Sinalização do Cálcio , Feminino , Receptores de Inositol 1,4,5-Trifosfato , Camundongos , Camundongos Endogâmicos , Receptores Citoplasmáticos e Nucleares/metabolismo
17.
Development ; 125(20): 4099-105, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9735370

RESUMO

Sperm extract (SE) of the ascidian, Ciona savignyi, injected into oocytes induced repetitive intracellular Ca2+ increases with kinetics consistent with those at fertilization and caused reinitiation and progression of meiosis as in fertilized oocytes with the formation of polar bodies. The Ca2+ response comprised two sets of Ca2+ oscillations separated by 5 minutes and correlated with the first and second meiotic metaphase. The effects of SE were dose dependent and the critical dose corresponded roughly to a single spermatozoon. In the first Ca2+ transient observed by confocal microscopy, a Ca2+ wave started from the SE injection site at the peripheral region of the oocyte and propagated across the ooplasm. The similar wave was produced by injection at the central region, starting from an arbitrary cortical area after 30 seconds, probably after SE had diffused to the cortex. The sensitivity to SE is thought to be preferentially higher in the cortex. The effective component of SE was heat-unstable, and its molecular weight was estimated as in the range between 10x10(4 )and 3x10(4) using membrane filters. These results suggest that, in ascidian fertilization, a cytosolic sperm protein factor is introduced to the oocyte cortex and induces Ca2+ waves and thereby meiotic resumption, leading to cell-cycle-correlated Ca2+ oscillations.


Assuntos
Sinalização do Cálcio , Fertilização , Meiose , Oócitos/metabolismo , Espermatozoides , Urocordados/fisiologia , Animais , Cálcio/metabolismo , Extratos Celulares/farmacologia , Relação Dose-Resposta a Droga , Temperatura Alta , Cinética , Masculino , Metáfase , Microinjeções , Peso Molecular , Transdução de Sinais
18.
Development ; 125(2): 293-300, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9486802

RESUMO

An increase in intracellular Ca2+ concentration ([Ca2+]i) at a focal plane was recorded simultaneously with sperm-egg binding and membrane current upon insemination of sea urchin Hemicentrotus pulcherrimus eggs. No change in current and [Ca2+]i occurred in the presence of jaspisin, a novel substance that inhibits metallo-endoproteinase and sperm-egg membrane fusion (S. Ikegami, H. Kobayashi, Y. Myotoishi, S. Ohta and K. H. Kato (1994) J. Biol. Chem. 269, 23262-23267). With low doses of jaspisin, a spermatozoon first produced a step inward current (I(on)) as an indication of gamete membrane fusion and then induced a local [Ca2+]i rise at the site of sperm attachment 6-10 seconds after I(on). The sperm, however, soon detached from the egg. Increasing inward current was abruptly cut off (I(off)) within 9-15 seconds and the local [Ca2+]i rise began to decline 1-3 seconds after I(off). In most cases, no further responses or an elevation of fertilization envelope (FE) occurred. In some cases, [Ca2+]i at the sperm attachment site increased again even after the sperm detached and triggered a Ca2+ wave which caused an activation current and FE formation. This recording of a gamete membrane-fusion-induced local [Ca2+]i rise, separated from the Ca2+ wave, is a key phenomenon for elucidating the initial sperm stimulation of the egg at fertilization.


Assuntos
Cálcio/metabolismo , Óvulo/metabolismo , Interações Espermatozoide-Óvulo/efeitos dos fármacos , Espermatozoides/fisiologia , Estirenos/farmacologia , Animais , Membrana Celular/fisiologia , Feminino , Masculino , Óvulo/fisiologia , Técnicas de Patch-Clamp , Ouriços-do-Mar
19.
Cell Struct Funct ; 23(5): 255-64, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9872566

RESUMO

We examined alterations in cell morphology and expression of adhesion molecules in response to a general protein kinase inhibitor K252a treatment of non-adherent colon adenocarcinoma Colo201 cells. K252a induced rapid cell adhesion and spreading with concomitant formation of actin stress fibers. A protein kinase A inhibitor KT5720 also induced cell adhesion, but the rate of spread was slower than that seen with K252a. These adhesions were mediated by integrin molecules since cell adhesion required Mg2+, Mn2+ or Ca2+, and was inhibited by monoclonal antibodies for integrins alpha2 and beta1. Indirect immunofluorescence microscopic observations revealed that integrin alpha2 and beta1 molecules in K252a-treated cells were concentrated at sites of focal adhesion, but expressions of integrin molecules were not modulated. Tyrosine phosphorylation of focal adhesion kinase (FAK) and paxillin increased during K252a- or KT5720-induced cell adhesion. Immunosuppressants FK506 and cyclosporin A suppressed the K252a-induced cell adhesion and abolished tyrosine phosphorylation of cellular proteins including FAK and paxillin. Furthermore, W7 and calmidazolium, inhibitors of calmodulin, also inhibited the cell adhesion. Based on findings that FK506 and cyclosporin A are inhibitors of the calcium calmodulin-dependent protein phosphatase, calcineurin, this phosphatase may regulate integrin-dependent cell adhesion and spread of Colo201 cells. This Colo201 cell model provides a pertinent system for studying molecules involved in signal transduction pathways and can shed light on mechanisms of metastasis and invasion of colon carcinoma cells.


Assuntos
Adenocarcinoma/patologia , Carbazóis/farmacologia , Neoplasias do Colo/patologia , Ciclosporina/farmacologia , Indóis/farmacologia , Proteína Quinase C/antagonistas & inibidores , Pirróis/farmacologia , Tacrolimo/farmacologia , Adesão Celular/efeitos dos fármacos , Moléculas de Adesão Celular/metabolismo , Proteínas do Citoesqueleto/farmacologia , Inibidores Enzimáticos/farmacologia , Matriz Extracelular/patologia , Quinase 1 de Adesão Focal , Proteína-Tirosina Quinases de Adesão Focal , Humanos , Imunossupressores/farmacologia , Alcaloides Indólicos , Integrinas/fisiologia , Metástase Neoplásica , Paxilina , Fosfoproteínas/farmacologia , Fosforilação , Proteínas Tirosina Quinases/metabolismo , Sulfonamidas/farmacologia , Células Tumorais Cultivadas , Tirosina/metabolismo
20.
J UOEH ; 19(3): 233-9, 1997 Sep 01.
Artigo em Japonês | MEDLINE | ID: mdl-9306500

RESUMO

Recently, because international standardization systems have been set up in many fields, it is necessary for Japanese companies to employ persons who have specific knowledge and techniques in regards to occupational health and safety. In this paper, therefore, we discuss Occupational Health and Safety Practice, Level 4, and try to compare it with Japanese licences. The standard was developed by the Occupational Health and Safety Lead Body (OHSLB) in England. This standard is intended for occupational health and safety practitioners working in general health and safety. We conclude that the training system for occupational health and safety practitioners in Japan must be developed more fully.


Assuntos
Licenciamento , Saúde Ocupacional , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Japão , Padrões de Referência , Reino Unido
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