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1.
Diabetes Obes Metab ; 16(6): 573-6, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24320758

RESUMEN

This study was performed to clarify the influence of liraglutide on gastric emptying in Japanese patients with type 2 diabetes. In 16 patients, the [(13) C]-acetate breath test was performed to compare gastric emptying before and after liraglutide treatment. We found two patterns of response, with gastric emptying being delayed by liraglutide in seven patients (delayers) and not delayed in nine patients (non-delayers). The mean increase of the maximum gastric emptying time was 31 ± 4 min (p < 0.01 vs. baseline) in the delayers, while it was only 2 ± 3 min (p = 0.60 vs. baseline) in the non-delayers. The delayers showed a greater early decrease of AUC-PG from 0 to 60 min, despite no increase of the plasma insulin level compared with non-delayers. In conclusion, the effect of liraglutide treatment on gastric emptying shows heterogeneity, and patients can be classified as delayers or non-delayers.


Asunto(s)
Diabetes Mellitus Tipo 2/tratamiento farmacológico , Vaciamiento Gástrico/efectos de los fármacos , Péptido 1 Similar al Glucagón/análogos & derivados , Hipoglucemiantes/administración & dosificación , Adulto , Anciano , Pueblo Asiatico , Glucemia/efectos de los fármacos , Pruebas Respiratorias , Femenino , Péptido 1 Similar al Glucagón/administración & dosificación , Péptido 1 Similar al Glucagón/efectos adversos , Humanos , Hipoglucemiantes/efectos adversos , Liraglutida , Masculino , Persona de Mediana Edad , Taquifilaxis
2.
J Hosp Infect ; 129: 181-188, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35820556

RESUMEN

BACKGROUND: A 1% potassium peroxymonosulphate-based environmental disinfectant (PPED) produces sodium hypochlorite when combined with sodium chloride, which functions as a disinfectant. However, little is known about the impact of hospital cleaning with PPED on hospital-onset Clostridioides difficile infection (HO-CDI). AIM: To reduce HO-CDI, we promoted antimicrobial stewardship and hospital ward cleaning with PPED: this study was conducted to evaluate their impact. METHODS: We began a promotion of post-prescription review with feedback for broad-spectrum antimicrobials and hospital ward cleaning with PPED. We reviewed the ratio of HO-CDI, PPED consumption, and days of therapy (DOT) of broad-spectrum antimicrobials between July 2014 and March 2018, dividing this time into the pre-promotion (July 2014 to June 2015) and post-promotion periods (July 2015 to March 2018). FINDINGS: Using interrupted time series analysis, an immediate significant change in HO-CDI was observed after intervention (P=0.03), although a downward trend was not observed over this period (P=0.19). Trends in PPED consumption significantly changed over this period (P=0.02). DOT of carbapenems decreased immediately after the intervention began (P<0.01). A Poisson regression analysis showed that PPED consumption and DOT of carbapenems were independent factors affecting HO-CDI (P=0.039 and 0.016, respectively). CONCLUSION: We revealed that DOT of carbapenems and use of PPED were associated with the HO-CDI ratio and that both interventions reduced the rate of HO-CDI. This is the first report on the impact of hospital ward cleaning with PPED on the reduction of HO-CDI.


Asunto(s)
Antiinfecciosos , Programas de Optimización del Uso de los Antimicrobianos , Clostridioides difficile , Infecciones por Clostridium , Infección Hospitalaria , Desinfectantes , Humanos , Potasio , Hipoclorito de Sodio , Cloruro de Sodio , Infección Hospitalaria/prevención & control , Infecciones por Clostridium/prevención & control , Hospitales , Carbapenémicos
3.
J Exp Med ; 190(5): 617-27, 1999 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-10477547

RESUMEN

The role of T helper type 1 (Th1) and Th2 cells in tumor immunity was investigated using Th cells induced from ovalbumin (OVA)-specific T cell receptor transgenic mice. Although Th1 cells exhibited stronger cytotoxicity than Th2 cells, both cell types completely eradicated tumors when transferred into mice bearing A20 tumor cells transfected with the OVA gene (A20-OVA). Th1 cells eradicated the tumor mass by inducing cellular immunity, whereas Th2 cells destroyed the tumor by inducing tumor necrosis. Both Th1 and Th2 cells required CD8(+) T cells to eliminate tumors, and neither of these cells were able to completely eliminate A20-OVA tumors from T and B cell-deficient RAG2(-/-) mice. Mice cured from tumors by Th1 and Th2 cell therapy rejected A20-OVA upon rechallenge, but CD8(+) cytotoxic T lymphocytes were induced only from spleen cells prepared from cured mice by Th1 cell therapy. Moreover, we demonstrated that Th1 and Th2 cells used distinct adhesion mechanisms during tumor eradication: the leukocyte function-associated antigen (LFA)-1-dependent cell-cell adhesion step was essential for Th1 cell therapy, but not for Th2 cell therapy. These findings demonstrated for the first time the distinct role of antigen-specific Th1 and Th2 cells during eradication of established tumors in vivo.


Asunto(s)
Neoplasias Experimentales/inmunología , Neoplasias Experimentales/terapia , Células TH1/inmunología , Células Th2/inmunología , Animales , Antígenos/genética , Adhesión Celular/inmunología , Citocinas/inmunología , Citotoxicidad Inmunológica , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/inmunología , Femenino , Memoria Inmunológica , Inmunoterapia Adoptiva , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Ratones Transgénicos , Modelos Biológicos , Neoplasias Experimentales/patología , Ovalbúmina/genética , Ovalbúmina/inmunología , Receptores de Antígenos de Linfocitos T/genética , Transfección
4.
J Exp Med ; 189(7): 1121-8, 1999 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-10190903

RESUMEN

The natural killer T (NKT) cell ligand alpha-galactosylceramide (alpha-GalCer) exhibits profound antitumor activities in vivo that resemble interleukin (IL)-12-mediated antitumor activities. Because of these similarities between the activities of alpha-GalCer and IL-12, we investigated the involvement of IL-12 in the activation of NKT cells by alpha-GalCer. We first established, using purified subsets of various lymphocyte populations, that alpha-GalCer selectively activates NKT cells for production of interferon (IFN)-gamma. Production of IFN-gamma by NKT cells in response to alpha-GalCer required IL-12 produced by dendritic cells (DCs) and direct contact between NKT cells and DCs through CD40/CD40 ligand interactions. Moreover, alpha-GalCer strongly induced the expression of IL-12 receptor on NKT cells from wild-type but not CD1(-/-) or Valpha14(-/-) mice. This effect of alpha-GalCer required the production of IFN-gamma by NKT cells and production of IL-12 by DCs. Finally, we showed that treatment of mice with suboptimal doses of alpha-GalCer together with suboptimal doses of IL-12 resulted in strongly enhanced natural killing activity and IFN-gamma production. Collectively, these findings indicate an important role for DC-produced IL-12 in the activation of NKT cells by alpha-GalCer and suggest that NKT cells may be able to condition DCs for subsequent immune responses. Our results also suggest a novel approach for immunotherapy of cancer.


Asunto(s)
Adyuvantes Inmunológicos/farmacología , Células Dendríticas/efectos de los fármacos , Galactosilceramidas/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Interleucina-12/biosíntesis , Células Asesinas Naturales/efectos de los fármacos , Receptores de Interleucina/biosíntesis , Animales , Citotoxicidad Inmunológica/efectos de los fármacos , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Sinergismo Farmacológico , Inmunidad Celular/efectos de los fármacos , Interferón gamma/biosíntesis , Interferón gamma/genética , Interleucina-12/genética , Interleucina-12/farmacología , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/metabolismo , Ligandos , Activación de Linfocitos/efectos de los fármacos , Subgrupos Linfocitarios/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Receptores de Interleucina/genética , Receptores de Interleucina-12 , Regulación hacia Arriba/efectos de los fármacos
5.
Br J Cancer ; 100(2): 389-98, 2009 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-19107131

RESUMEN

We previously reported hedgehog (Hh) signal activation in the mucus-secreting pit cell of the stomach and in diffuse-type gastric cancer (GC). Epithelial-mesenchymal transition (EMT) is known to be involved in tumour malignancy. However, little is known about whether and how both signallings cooperatively act in diffuse-type GC. By microarray and reverse transcription-PCR, we investigated the expression of those Hh and EMT signalling molecules in pit cells and in diffuse-type GCs. How both signallings act cooperatively in those cells was also investigated by the treatment of an Hh-signal inhibitor and siRNAs of Hh and EMT transcriptional key regulator genes on a mouse primary culture and on human GC cell lines. Pit cells and diffuse-type GCs co-expressed many Hh and EMT signalling genes. Mesenchymal-related genes (WNT5A, CDH2, PDGFRB, EDNRA, ROBO1, ROR2, and MEF2C) were found to be activated by an EMT regulator, SIP1/ZFHX1B/ZEB2, which was a target of a primary transcriptional regulator GLI1 in Hh signal. Furthermore, we identified two cancer-specific Hh targets, ELK1 and MSX2, which have an essential role in GC cell growth. These findings suggest that the gastric pit cell exhibits mesenchymal-like gene expression, and that diffuse-type GC maintains expression through the Hh-EMT pathway. Our proposed extensive Hh-EMT signal pathway has the potential to an understanding of diffuse-type GC and to the development of new drugs.


Asunto(s)
Células Epiteliales/metabolismo , Mucosa Gástrica/metabolismo , Proteínas Hedgehog/metabolismo , Neoplasias Intestinales/metabolismo , Mesodermo/metabolismo , Transducción de Señal , Neoplasias Gástricas/metabolismo , Animales , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Células Cultivadas , Mucosa Gástrica/citología , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Proteínas Hedgehog/genética , Humanos , Técnicas para Inmunoenzimas , Neoplasias Intestinales/patología , Mesodermo/citología , Ratones , Ratones Endogámicos C57BL , Invasividad Neoplásica , ARN Interferente Pequeño/farmacología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Neoplasias Gástricas/patología
6.
Br J Pharmacol ; 153 Suppl 1: S457-64, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18311159

RESUMEN

The intensity and duration of host responses are determined by protective mechanisms that control tissue injury by dampening down inflammation. Adenosine generation and consequent effects, mediated via A2A adenosine receptors (A2AR) on effector cells, play a critical role in the pathophysiological modulation of these responses in vivo. Adenosine is both released by hypoxic cells/tissues and is also generated from extracellular nucleotides by ecto-enzymes e.g. CD39 (ENTPD1) and CD73 that are expressed by the vasculature and immune cells, in particular by T regulatory cell. In general, these adenosinergic mechanisms minimize the extent of collateral damage to host tissues during the course of inflammatory reactions. However, induction of suppressive pathways might also cause escape of pathogens and permit dissemination. In addition, adenosinergic responses may inhibit immune responses while enhancing vascular angiogenic responses to malignant cells that promote tumor growth. Novel drugs that block A2AR-adenosinergic effects and/or adenosine generation have the potential to boost pathogen destruction and to selectively destroy malignant tissues. In the latter instance, future treatment modalities might include novel 'anti-adenosinergic' approaches that augment immune clearance of malignant cells and block permissive angiogenesis. This review addresses several possible pharmacological modalities to block adenosinergic pathways and speculates on their future application together with impacts on human disease.


Asunto(s)
Antagonistas del Receptor de Adenosina A2 , Adenosina/fisiología , Linfocitos T Reguladores/efectos de los fármacos , Adenosina/antagonistas & inhibidores , Adenosina/metabolismo , Animales , Espacio Extracelular/metabolismo , Humanos , Inmunoterapia , Inflamación/inmunología , Inflamación/patología , Receptores Acoplados a Proteínas G/efectos de los fármacos , Linfocitos T Reguladores/inmunología
8.
Clin Exp Rheumatol ; 26(1): 5-12, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18328140

RESUMEN

OBJECTIVE: To quantify the activated B cells in the peripheral blood and salivary glands of patients with Sjögren's syndrome (SS) by analyzing the expression of RP105 molecule on the B cells. METHODS: The expression of RP105 on the peripheral blood B cells of patients with SS (19 cases) was analyzed by flow cytometry. RP105-positive and negative B cells were sorted and cultured in vitro and the amount of immunoglobulins (IgG and IgM) produced in the supernatant was measured by enzyme-linked immunosorbent assay (ELISA). Salivary gland biopsy samples from 9 SS patients were histologically evaluated and the sequential frozen sections were separately immunostained by anti-RP105 and anti-CD20 monoclonal antibodies. RESULTS: A significantly higher proportion of peripheral blood RP105-negative B cells was found in SS patients than in healthy individuals. RP105-negative, but not positive, B cells from SS patients were capable of producing IgG and IgM spontaneously in vitro, which was enhanced by the addition of Staphylococcus aureus Cowan I strain (SAC) or IL-6. Salivary glands from 2 of 9 SS patients were found to have lymphoid follicles whose germinal centers consisted of RP105-negative B cells. Moreover, a larger proportion of B cells extensively infiltrating the area other than lymphoid follicles was also RP105-negative. CONCLUSION: RP105-negative B cells, a subset of highly activated and well differentiated B cells, which are increased in number in the peripheral blood and extensively infiltrate salivary glands, may be responsible for the production of class-switched immunoglobulin in SS. In addition, those cells might be associated with the inflammation and tissue damage of the salivary glands.


Asunto(s)
Antígenos CD/análisis , Linfocitos B/química , Glándulas Salivales/citología , Síndrome de Sjögren/patología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antígenos CD/sangre , Femenino , Citometría de Flujo , Humanos , Inmunoglobulina G/análisis , Inmunoglobulina M/análisis , Activación de Linfocitos/fisiología , Recuento de Linfocitos , Masculino , Persona de Mediana Edad , Síndrome de Sjögren/sangre
9.
J Periodontol ; 79(10): 1984-90, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18834255

RESUMEN

BACKGROUND: The purpose of this study was to investigate the effects of low-intensity pulsed ultrasound (LIPUS) stimulation on the proliferation and differentiation of cementoblast lineage cells. METHODS: An immortalized human periodontal ligament cell line (HPL) showing immature cementoblastic differentiation was used. Cultured HPL cells were subjected to LIPUS exposure (frequency = 1 MHz; pulsed 1:4; intensity = 30 mW/cm(2)) or sham exposure for 15 minutes per day. Expression levels of alkaline phosphatase (ALP), type I collagen (Col-I), runt-related gene 2 (Runx2), bone sialoprotein (BSP), osteocalcin (OCN), and osteopontin (OPN) mRNA were analyzed with real-time polymerase chain reaction analysis. Furthermore, ALP activity, collagen synthesis, and protein level of Runx2 were examined after 6 days of LIPUS exposure. RESULTS: mRNA and protein levels of ALP, Col-I, and Runx2 were significantly increased by LIPUS exposure compared to controls, whereas BSP, OCN, and OPN mRNA expression could not be detected in HPL cells, irrespective of LIPUS exposure. CONCLUSION: LIPUS enhanced ALP activity, collagen synthesis, and Runx2 expression of HPL cells, which provides important insight into the promotion of early cementoblastic differentiation of immature cementoblasts.


Asunto(s)
Cemento Dental/citología , Ultrasonido , Fosfatasa Alcalina/análisis , Biomarcadores/análisis , Western Blotting , Diferenciación Celular , Línea Celular , Linaje de la Célula , Proliferación Celular , Células Cultivadas , Colágeno/biosíntesis , Colágeno Tipo I/análisis , Subunidad alfa 1 del Factor de Unión al Sitio Principal/análisis , Humanos , Sialoproteína de Unión a Integrina , Osteocalcina/análisis , Osteopontina/análisis , Ligamento Periodontal/citología , Reacción en Cadena de la Polimerasa , ARN/análisis , Sialoglicoproteínas/análisis
10.
Clin Exp Rheumatol ; 24(5 Suppl 42): S115-9, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-17067441

RESUMEN

OBJECTIVE: [corrected] To determine the clinical characteristics of patients with myelodysplastic syndrome (MDS)-associated Behçet's disease (BD) in Japan. METHODS: 54 Japanese cases of MDS-associated BD obtained from the literature and from our own clinical experience were reviewed. The clinical features of MDS-associated BD were compared with those of the 1991 nationwide BD survey in Japan. RESULTS: In MDS-associated BD, the average age at onset was 42.6 years, which was 6.9 years later than for all BD patients; females developed disease more frequently than males (male: female ratio = 0.80). In MDS-associated BD cases, the occurrence of eye lesions was significantly lower, the frequency of intestinal lesions was markedly higher, and the rate of HLA-B51 positivity was lower than that in all BD. BD and MDS developed nearly simultaneously in 49.0% of cases; BD preceded MDS in 31.4% of the cases. The distribution of the age at BD onset showed two peaks, one in the 3rd decade and the other in the 6th decade. Females were more likely to develop younger-onset disease, while men were more likely to develop older-onset MDS-associated BD. Furthermore, in the older-onset group, BD was diagnosed together with or after the diagnosis of MDS, while half of the younger-onset group developed BD earlier than MDS. CONCLUSION: MDS-associated BD patients form a distinct subset of patients. There may, in fact, be two major groups of MDS-associated BD patients based on age, gender, and temporal relationship of the two diseases.


Asunto(s)
Síndrome de Behçet/complicaciones , Síndromes Mielodisplásicos/complicaciones , Adolescente , Adulto , Edad de Inicio , Anciano , Anciano de 80 o más Años , Síndrome de Behçet/etnología , Síndrome de Behçet/patología , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Japón , Masculino , Persona de Mediana Edad , Síndromes Mielodisplásicos/etnología , Síndromes Mielodisplásicos/patología , Estudios Retrospectivos , Razón de Masculinidad
11.
Biochim Biophys Acta ; 984(2): 151-7, 1989 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-2527563

RESUMEN

We have studied lipid peroxidation and Ca2+-ATPase activity of the porcine intestinal brush-border membranes using a oxygen-radical-generating system consisting of dithiothreitol (DTT)/Fe2+ and tert-butyl hydroperoxide (t-BuOOH). The rates of lipid peroxidation were measured by formation of thiobarbituric acid-reactive substances (TBAR) and conjugated diene. Incubation of the membranes with DTT/Fe2+ in the absence and presence of t-BuOOH resulted in a slight (about 20%) and a marked (about 50%) inhibition of Ca2+-ATPase activity, respectively. The degree of inhibition was dependent on the hydroperoxide concentration. Addition of thiourea effectively protected Ca2+-ATPase activity but catalase and superoxide dismutase showed a slight and no effect on protection of the ATPase activity, respectively. Results of kinetic studies on the ATPase activity with varying ATP and Ca2+ concentrations revealed that the decrease in the enzyme activity by treatment with these oxidizing agents is mainly due to decrease of the Vmax value. Modification of SH groups in the membrane proteins by thiol group reagents such as N-ethylmaleimide, monoiodoacetate and monoiodacetamide did not induce the inhibition of Ca2+-ATPase activity. From these results, it is suggested that inhibition of the ATPase activity of the membranes by treatment with DTT/Fe2+ in the presence and absence of t-BuOOH is dependent on lipid peroxidation and that oxidative modification of SH groups may not be directly involved to the loss of the ATPase activity. In addition, results of the fluorescence anisotropy measurements of pyrene-labeled membranes suggested that change in the Ca2+-ATPase activity is partly related to a decrease in the membrane lipid fluidity.


Asunto(s)
ATPasas Transportadoras de Calcio/metabolismo , Intestino Delgado/metabolismo , Peroxidación de Lípido , Microvellosidades/metabolismo , Animales , Ditiotreitol/farmacología , Cinética , Peroxidación de Lípido/efectos de los fármacos , Músculo Liso/metabolismo , Peróxidos/farmacología , Reactivos de Sulfhidrilo/farmacología , Porcinos , terc-Butilhidroperóxido
12.
Biochim Biophys Acta ; 902(1): 46-52, 1987 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-2955811

RESUMEN

The brush-border membrane from the porcine small intestine possesses Ca2+-dependent ATPase activity. The Ca2+ stimulation of ATP hydrolysis by the membranes is biphasic with a high affinity (Km = 0.38 microM) and a low affinity (Km = 98.3 microM). Treatment of the membrane vesicles with n-heptylthioglucoside did not cause further increase of the Ca2+-ATPase activity. Mg2+ also stimulates the ATP hydrolysis in the absence of Ca2+ but decreases the Ca2+-ATPase activities at 0.59 and 200 microM free Ca2+. The Ca2+-ATPase activities are not inhibited by addition of vanadate, ouabain, sodium azide and alkaline phosphatase inhibitors (theophylline and L-phenylalanine), irrespective of the Ca2+ concentrations in medium. A specific calmodulin-inhibitor W-7 (up to 30 microM) also did not influence on the Ca2+-ATPase activities at 0.59 and 200 microM free Ca2+. The Ca2+-ATPase activities at 0.59 and 200 microM free Ca2+ show no specificity for ATP. ADP, GTP and CTP could also be used as substrates. From these results, it is suggested that the porcine intestinal brush-border membrane possesses Mg2+-independent Ca2+-ATPase activity and that the Ca2+-ATPase activities with biphasic responses for Ca2+ stimulation observed in the present study reside on the same protein. The physiological functions of the Ca2+-ATPase in the membranes, however, remain unknown at present.


Asunto(s)
Adenosina Trifosfato/metabolismo , ATPasas Transportadoras de Calcio/metabolismo , Calcio/farmacología , Intestino Delgado/enzimología , Fosfatasa Alcalina/antagonistas & inhibidores , Animales , Azidas/farmacología , ATPasas Transportadoras de Calcio/antagonistas & inhibidores , Calmodulina/antagonistas & inhibidores , Magnesio/farmacología , Microvellosidades/enzimología , Nucleótidos/metabolismo , Ouabaína/farmacología , Azida Sódica , Especificidad por Sustrato , Porcinos , Tioglicósidos/farmacología , Vanadatos , Vanadio/farmacología
13.
Biochim Biophys Acta ; 689(2): 370-4, 1982 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-7115715

RESUMEN

Adenylate cyclase in the membrane fractions of bovine and rat brains, but not in rat liver plasma membranes, was solubilized by treatment with Fe2+ (10 microM) plus dithiothreitol (5 mM). Solubilization of the enzyme by these agents was completely prevented by simultaneous addition of N,N'-diphenyl-p-phenylenediamine (DPPD), an inhibitor of lipid peroxidation. Ascorbic acid also solubilized the enzyme from the brain membranes. Lipid peroxidation of the brain membranes was characterized by a selective loss of phosphatidylethanolamine. Solubilization of membrane-bound enzymes by Fe2+ plus dithiothreitol was not specific for adenylate cyclase, because phosphodiesterase, thiaminediphosphatase and many other proteins were also solubilized. Solubilized adenylate cyclase had a high specific activity and was not activated by either NaF, 5'-guanylyl imidodiphosphate (Gpp[NH]p) or calmodulin. These results suggested that lipid peroxidation of the brain membranes significantly solubilized adenylate cyclase of high specific activity.


Asunto(s)
Adenilil Ciclasas/aislamiento & purificación , Antioxidantes/farmacología , Corteza Cerebral/enzimología , Peróxidos Lipídicos/metabolismo , Fenilendiaminas/farmacología , Fosfolípidos/aislamiento & purificación , Adenilil Ciclasas/metabolismo , Animales , Bovinos , Membrana Celular/enzimología , Corteza Cerebral/análisis , Ditiotreitol/farmacología , Hierro/farmacología , Cinética , Solubilidad
14.
Biochim Biophys Acta ; 812(1): 84-90, 1985 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-3967016

RESUMEN

The effects of salt concentration gradient (inside to outside) on the lipid peroxidation of porcine intestinal brush-border membrane vesicles have been studied and several interesting features of the peroxidation have been elucidated. The addition of dithiothreitol and Fe2+ is far more effective in induction of the lipid peroxidation than any of the other metal ion species tested (Fe3+, Cu2+, Ni2+, Zn2+ and Cr3+). The peroxidation rate of the membrane vesicles induced by dithiothreitol plus Fe2+ was sensitive for the incubation temperature and was increased with increase of the temperature. Imposition of an inward salt concentration gradient on the membrane vesicles preloaded with 300 mM mannitol by addition of 100 mM chloride of K+, Na+, Li+, Rb+, NH4+ or choline to medium produces a very large reduction of the lipid peroxidation induced by dithiothreitol plus Fe2+. The membrane peroxidation is depressed more with the mannitol (300 mM)-preloaded vesicles than with the K2SO4 (100 mM)-preloaded vesicles when they are incubated in medium containing 20-100 mM of K2SO4. Addition of membrane-permeant anions such as SCN- and I-, but not addition of NO3-, to incubation medium has been found to decrease markedly the lipid peroxidation of the mannitol-preloaded vesicles. From these results it is suggested that the lipid peroxidation of the brush-border membranes by addition of dithiothreitol plus Fe2+ is sensitively changed with change in ionic strength.


Asunto(s)
Intestinos/ultraestructura , Peróxidos Lipídicos/metabolismo , Animales , Ácido Ascórbico/farmacología , Hidroxianisol Butilado/farmacología , Ditiotreitol/farmacología , Compuestos Ferrosos/farmacología , Lípidos de la Membrana/metabolismo , Microvellosidades/metabolismo , Concentración Osmolar , Sulfatos/farmacología , Porcinos , Factores de Tiempo
15.
Biochim Biophys Acta ; 878(1): 25-31, 1986 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-3730412

RESUMEN

A phospholipid transfer protein from bovine liver was used to transfer exogenous ([14C]linoleoylphosphatidylethanolamine [14C]linoleoyl PE) into synaptic membranes and synaptosomes without modifying the lipid compositions in order to study the intrinsic activity of phospholipase A2 of the preparations. Results were compared with the conventional method in which the substrate was simply dispersed with the enzyme preparations. Liberation of [14C]linoleic acid from [14C]linoleoyl PE-preloaded synaptic membranes by the transfer protein continued almost linearly over 60 min of incubation in the presence of Ca2+. The dose-response curve of Ca2+ for the activity of phospholipase A2 obtained in the present method was slightly shifted to the left in comparison with the conventional method: Ca2+ even at the concentration of 100 microM significantly enhanced the enzyme activity. Requirement of Ca2+ for the reaction is more specific in the present method than in the conventional one. When synaptosomes were prelabeled with [14C]linoleoyl PE by the transfer protein, the liberation of [14C]linoleic acid during the incubation at 37 degrees C increased linearly over 2 min. The liberation of [14C]linoleic acid was significantly enhanced in the presence of 56 mM KCl, 50 microM veratridine and 50 microM calcium ionophore A23187. These agents did not stimulate the reaction in the absence of Ca2+.


Asunto(s)
Proteínas Portadoras/metabolismo , Lípidos de la Membrana/metabolismo , Proteínas de la Membrana , Fosfolipasas A/metabolismo , Fosfolipasas/metabolismo , Proteínas de Transferencia de Fosfolípidos , Membranas Sinápticas/enzimología , Animales , Calcio/metabolismo , Cationes Bivalentes , Bovinos , Concentración de Iones de Hidrógeno , Masculino , Potenciales de la Membrana , Fosfolipasas A2 , Fosfolípidos/metabolismo , Ratas , Sinaptosomas/metabolismo
16.
Biochim Biophys Acta ; 1475(3): 265-72, 2000 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-10913825

RESUMEN

We have identified two genomic DNA fragments from the human pathogenic fungi, Candida albicans (CaVIG9) and Candida glabrata (CgVIG9) that encode GDP-mannose pyrophosphorylase, a key enzyme for protein glycosylation. The VIG9 homologues of CaVIG9 and CgVIG9 complement an identified protein glycosylation-defective mutation, vig9, of Saccharomyces cerevisiae. The nucleotide sequences of the ORFs, which are 83 and 90% identical to that of the ScVIG9 protein, respectively, showed a predicted gene product homologous to S. cerevisiae GDP-mannose pyrophosphorylase. We examined the enzyme activity of a glutathione S-transferase fusion of each VIG9 gene to synthesize GDP mannose in the cell extracts of a heterologous Escherichia coli expression system. We also developed a method for detecting the enzyme activity using a non-radioactive substrate that would be applicable to high throughput screening.


Asunto(s)
Candida albicans/genética , Proteínas Fúngicas/genética , Nucleotidiltransferasas/genética , Secuencia de Aminoácidos , Clonación Molecular , Escherichia coli/metabolismo , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Prueba de Complementación Genética , Guanosina Difosfato Manosa/análisis , Guanosina Difosfato Manosa/biosíntesis , Datos de Secuencia Molecular , Nucleotidiltransferasas/química , Nucleotidiltransferasas/metabolismo , Homología de Secuencia de Aminoácido
17.
Biochim Biophys Acta ; 1394(1): 23-32, 1998 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-9767089

RESUMEN

The cho1/pss mutant of Saccharomyces cerevisiae, which is auxotrophic for choline or ethanolamine because of the deficiency in phosphatidylserine synthesis, grew in the presence of 0.05 mM phosphatidylcholine (PC) with octanoic acids (diC8PC) or decanoic acids (diC10PC), but not in the presence of PC with longer acyl residues. It did not grow in the presence of the soluble hydrolytic products of PC, phosphorylcholine or glycerophosphorylcholine, at comparable concentrations. Addition of 10 mM hemicholinium-3, a choline transport inhibitor, or disruption of the CTR gene, which encodes a choline transporter, inhibited the growth of the cho1/pss mutant in the presence of choline, but not in the presence of 0.1 mM diC8PC. Under diC8PC-supported growth conditions, octanoic acid was barely detectable in the cellular phospholipid fraction, but was recovered in the culture medium as the free acid, and the phosphatidylethanolamine (PE) content was low in comparison to the choline-supported conditions. These results suggest that PCs with short acyl residues were taken up by the cho1/pss mutant and remodeled as they were used, and that PCs with short acyl residues do not inhibit conversion of PE to PC. The current results provide a new direction in the analysis of intracellular phospholipid movement and metabolism in yeast.


Asunto(s)
Fosfolípidos/metabolismo , Saccharomyces cerevisiae/metabolismo , Caprilatos/metabolismo , Mutación , Fosfatidilcolinas/metabolismo , Fosfatidilserinas/biosíntesis , Polisorbatos/farmacología , Saccharomyces cerevisiae/crecimiento & desarrollo
18.
Biochim Biophys Acta ; 1034(1): 4-10, 1990 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-2139347

RESUMEN

EDTA-extractable protein (EEP) is known to be a major lens membrane protein with a molecular mass in the range 32 kDa to 38 kDa, and is also known to bind to the lens membrane and phospholipid-containing liposomes in a calcium-dependent manner. Recent results (Russell, P., Zelenka, P., Martensen, J., and Reid, T.W. (1977) Curr. Eye Res. 6, 533-538) on antibody cross-reactivity have demonstrated that a 34-35 kDa component of EEP is identical to calpactin I (lipocortin II). In this study, we have identified and purified three distinct 34 kDa components of EEP (designated as EEP-34A1, EEP-34A2 and EEP-34B) from bovine lens that inhibit phospholipase A2 activity. These proteins bind to phospholipid-containing liposome and F-actin in a calcium-dependent fashion. Two-dimensional electrophoresis demonstrates that the three proteins were distinct from one another. However, immunochemical studies and one-dimensional peptide mapping indicate that EEP-34A1 and EEP-34B are very similar. Our results also indicate that EEP-34A1 is very similar to calpactin II and that EEP-34A2 corresponds to calpactin I. The bovine lens 34-35 kDa component of EEP is a mixture of proteins rather than a single protein.


Asunto(s)
Cristalinas/aislamiento & purificación , Ácido Edético/farmacología , Actinas/metabolismo , Aminoácidos/análisis , Animales , Anexinas , Calcio/farmacología , Proteínas de Unión al Calcio/análisis , Bovinos , Cromatografía en Gel , Reacciones Cruzadas , Cristalinas/análisis , Cristalinas/inmunología , Electroforesis en Gel Bidimensional , Fosfolipasas A/antagonistas & inhibidores , Fosfolipasas A2 , Fosfolípidos/metabolismo
19.
Biochim Biophys Acta ; 1236(1): 163-9, 1995 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-7794946

RESUMEN

In an alkane-assimilating yeast, Candida maltosa, a cultivation on alkane causes both induction of endoplasmic reticulum (ER)-resident membrane proteins, such as cytochrome P-450, and proliferation of ER. In this study, individual genes for alkane-inducible forms of cytochrome P-450 (P-450alk) were homologously overexpressed in C. maltosa using a galactose-inducible expression system developed in this yeast. Immunoelectron microscopy revealed that, upon the overexpression, a dramatic proliferation of ER occurred, in which overproduced P-450alk protein accumulated. The proliferated membranes were mainly tubular forms and stacks of paired membranes were also observed after prolonged expression. The tubular forms were morphologically very similar to the proliferated ER in alkane-induced C. maltosa cells. The observed proliferation of ER membranes by homologous overproduction of P-450alk, here depicted, will provide a unique opportunity for investigating the mechanisms by which cells regulate ER biogenesis, in comparison with the intrinsic form of ER proliferation.


Asunto(s)
Candida/enzimología , Sistema Enzimático del Citocromo P-450/biosíntesis , Retículo Endoplásmico/metabolismo , Retículo Endoplásmico/ultraestructura , Vectores Genéticos , Membranas Intracelulares/metabolismo , Proteínas de la Membrana/biosíntesis , Microscopía Inmunoelectrónica
20.
J Bone Miner Res ; 16(10): 1829-36, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11585347

RESUMEN

We reported that genistein, a soybean isoflavone, prevents bone loss caused by estrogen deficiency, without undesirable effects on the uterus. In this study, we examined cooperative effects of genistein administration and running exercise on bone mass in ovariectomized (OVX) mice. Female mice aged 7 weeks were either sham-operated or OVX and divided into six groups: (1) sham; (2) OVX; (3) OVX, treated with genistein at a submaximal dose (0.4 mg/day) subcutaneously (G); (4) OVX, exercised on a treadmill daily for 30 minutes/day at 12 m/minute on a 10 degree uphill slope (Ex); (5) OVX, given genistein and exercised (ExG); and (6) OVX, treated with 17beta-estradiol (0.03 microg/day) in the same manner as genistein (E2). Four weeks after intervention, bone mass was estimated by dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT). Bone mineral density (BMD) of the whole femur measured by DXA was higher in both the G and the Ex groups than in the OVX group. Furthermore, BMD in the ExG group was significantly higher than that in the groups receiving either intervention alone. Bone area in distal region of the femur was significantly higher in Ex and ExG groups as compared with those in the OVX and G groups. pQCT analysis showed that the cross-sectional areas (CSAs) and periosteum perimeter at midshaft of the femur did not differ in the sham and OVX groups but were significantly higher in Ex and ExG groups. Histomorphometric analysis showed that bone formation rate/bone surface (BFR/BS) was significantly higher in both Ex and ExG groups as compared with that in non-exercised groups. The bone volume (BV/TV) in the distal femoral cancellous bone was lower in the OVX than that in the sham group, and it was restored completely in the ExG group, as in the E2 group. Thickness of the trabecular bone (Tb.Th) was higher in Ex and ExG groups than that in the OVX and G groups. These results indicate that the combined intervention of moderate exercise and the submaximal dose of genistein administration show a cooperative effect in preventing bone loss in OVX mice.


Asunto(s)
Huesos/efectos de los fármacos , Genisteína/farmacología , Esfuerzo Físico/fisiología , Animales , Peso Corporal/efectos de los fármacos , Densidad Ósea/efectos de los fármacos , Huesos/fisiología , Femenino , Fémur/efectos de los fármacos , Fémur/patología , Genisteína/administración & dosificación , Ratones , Tamaño de los Órganos , Ovariectomía , Útero/efectos de los fármacos
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