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1.
Rev Sci Instrum ; 95(8)2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39158396

RESUMEN

The Korea Superconducting Tokamak Advanced Research (KSTAR) tokamak is capable of operating at a wide range of toroidal magnetic fields up to 3.5 T at the major radius. The electron cyclotron emission (ECE) diagnostic on KSTAR is required to cover a broad frequency range for electron temperature profile measurements in both the low and high field sides. To meet these broadband requirements, the ECE system consists of W-band (78-110 GHz) and D-band (110-162 GHz) heterodyne radiometers. The two radiometers are connected to 28 and 48 detection channels, respectively. However, since the absolute ECE calibration based on the hot-cold calibration has been very challenging, an alternative method of calibration was performed using Thomson scattering measurements and varying toroidal magnetic fields. As the toroidal magnetic field is scanned from 1.6 to 3.2 T in steps of 0.2 T, most of the 76 ECE channels are calibrated relatively by the electron temperature values of Thomson scattering in a narrow region (0.2 < r/a <0.6). In this article, the methodological details of the ECE calibration are described. In addition, to demonstrate the robustness of the ECE calibration factors, the calibrated electron temperature profiles from ECE measurements are compared with the ion temperature profiles in terms of the plasma position as the plasma positon shifts outward.

2.
Orthod Craniofac Res ; 2018 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-29671936

RESUMEN

OBJECTIVE: To investigate the effects of parathyroid hormone (PTH) on tooth movement in ovariectomized (OVX) rats by comparing the tooth movement distance and relapse and by examining the alveolar bone microstructure. MATERIALS AND METHODS: Thirty 8-week-old female rats were classified into 3 groups: sham-operated, OVX and ovariectomized rats injected with PTH (PTH). Eight weeks later, a closed-coil spring appliance was placed between the maxillary incisor and the first molar and then activated with 50 cN of force. During tooth movement, 30 µg/kg of PTH was administered 3 times per week in the PTH group. Tooth movement distances were measured weekly. Five rats in each group were killed after 3 weeks for microcomputerized tomographic analysis, and the remaining 5 rats in each group were killed at an additional 3 weeks after the removal of the appliance to measure relapsed distance. RESULTS: The OVX group showed significantly greater tooth movement compared to those in the other 2 groups at 2 and 3 weeks (P < .05). The relapse distance and relapse percentage for the OVX group were higher; however, it did not differ significantly from the PTH group. On micro-CT analysis, bone volume/tissue volume ratio and bone mineral density in the PTH group were significantly greater than in the OVX group (P < .05). CONCLUSIONS: Application of PTH did not promote tooth movement in OVX rat, however, did lead to decrease in relapse tendency. Therefore, the application of PTH during orthodontic treatment of patients with osteoporosis should be carefully considered.

3.
J Xray Sci Technol ; 25(3): 505-514, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28157115

RESUMEN

The King AbdulAziz City for Science & Technology in the Kingdom of Saudi Arabia plans to build a 10 MeV, 15 kW linear accelerator (LINAC) for electron beam and X-ray. The accelerator will be supplied by EB Tech, Republic of Korea, and the design and construction of the accelerator building will be conducted in the cooperation with EB Tech. This report presents the shielding analysis of the accelerator building using the Monte Carlo N-Particle Transport Code (MCNP). In order to improve the accuracy in estimating deep radiation penetration and to reduce computation time, various variance reduction techniques, including the weight window (WW) method, the deterministic transport (DXTRAN) spheres were considered. Radiation levels were estimated at selected locations in the shielding facility running MCNP6 for particle histories up to 1.0×10+8. The final results indicated that the calculated doses at all selected detector locations met the dose requirement of 50 mSv/yr, which is the United State Nuclear Regulatory Commission (U.S. NRC) requirement.


Asunto(s)
Aceleradores de Partículas , Protección Radiológica , Electrones , Diseño de Equipo , Método de Montecarlo , Protección Radiológica/instrumentación , Protección Radiológica/métodos , Rayos X
4.
Pharmazie ; 72(12): 728-735, 2017 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-29441957

RESUMEN

smartLipids® as the 3rd lipid nanoparticle generation are made from a complex lipid mixture. The chaotic particle matrix structure provides higher loading with actives and a firmer inclusion inside the particle matrix being more protective for chemically labile molecules. Thus, these particles were used to develop an optimized retinol formulation. As a new approach, the old concept of the core-shell SLN particles was combined with the novel smartLipids® technology as new stabilization model. Particles were produced by hot high pressure homogenization, loaded with increasing amounts of retinol (5%, 15%, 20%), and both the physical (size, crystallinity) and chemical stability were monitored. According to the core-shell model, the retinol precipitates first, forming a core. Then, in the final solidification stage of the particles the retinol core gets surrounded by a shell of lipid-retinol eutectic mixture. With increasing retinol content, more retinol precipitates in the core and is chemically protected. The model was confirmed by the stability data obtained, e.g. with 5%, 15% and 20% retinol loading, after 60 days of storage 37%, 59% and 75% of retinol remained in the particle suspensions. Thus, chemical stability increased with loading. Size remained unchanged at about 200 nm. Crystallinity showed absence of polymorphic transitions, which can cause expulsion of active from the particle matrix, leading to degradation. After incorporation of the particles into a gel as dermal formulation, similar stability was observed. The developed concept can be transferred to other chemically labile dermal actives, in cosmetics and pharma.


Asunto(s)
Fármacos Dermatológicos/administración & dosificación , Lípidos/química , Nanopartículas , Vitamina A/administración & dosificación , Química Farmacéutica/métodos , Cristalización , Fármacos Dermatológicos/química , Estabilidad de Medicamentos , Almacenaje de Medicamentos , Tamaño de la Partícula , Tecnología Farmacéutica/métodos , Factores de Tiempo , Vitamina A/química
5.
J Appl Microbiol ; 115(2): 517-26, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23607518

RESUMEN

AIMS: Atopic dermatitis (AD) is an inflammatory skin disease. Probiotics have been reported to modulate immune responses and thus are now being suggested as potential treatments for allergies. In this study, we investigated the inhibitory effects of Lactobacillus sakei probio 65 isolated from Kimchi on artificially inducing AD in NC/Nga mice. METHODS AND RESULTS: Oral administration of viable or heat-inactivated Lact. sakei probio 65 improved the condition of skin and reduced scratching frequency. Serum levels of IgE and cutaneous T-cell-attracting chemokine (CTACK) were significantly decreased by this therapy. Dead Lact. sakei probio 65 also decreased IL-4 and IL-6 serum concentrations. Moreover, both live and dead Lact. sakei probio 65 inhibited the expression of Thymus and activation-regulated chemokine and CTACK in AD-like skin lesions. The increased levels of Foxp3 expression in the lesional skin and ears were also suppressed by Lact. sakei probio 65. In addition, Lact. sakei probio 65 inhibited ß-hexosaminidase release and the secretion of IL-4, TNF-α and IL-6 from RBL-2H3 cells. CONCLUSIONS: Oral treatment with both viable and heat-inactivated Lact. sakei probio 65 inhibits skin inflammation and AD-like skin lesions, as well as mast cell activation. SIGNIFICANCE AND IMPACT OF THE STUDY: Lactobacillus sakei probio 65 has an inhibitory effect on atopic dermatitis-like skin lesions and may represent an effective new anti-inflammatory agent.


Asunto(s)
Dermatitis Atópica/terapia , Lactobacillus , Probióticos/uso terapéutico , Animales , Línea Celular Tumoral , Dermatitis Atópica/inmunología , Dermatitis Atópica/patología , Inmunoglobulina E/sangre , Interleucina-4/sangre , Interleucina-6/sangre , Masculino , Ratones , Piel/efectos de los fármacos , Piel/patología , Factor de Necrosis Tumoral alfa/metabolismo
6.
Cell Mol Life Sci ; 65(20): 3290-303, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18818879

RESUMEN

Ikaros is known as a critical regulator of lymphocyte development. We examined the regulatory role of Ikaros in LPS/IFN-gamma-induced inducible nitric oxide synthase (iNOS) expression by macrophages. Our results showed that IK6 (Ikaros dominant negative isoform) induction increases the iNOS expression. Ikaros DNA binding activity on the iNOS promoter was decreased, and a mutation of the Ikaros-binding site on the iNOS promoter resulted in an increase in LPS/IFN-gamma-induced iNOS expression. LPS/IFN-gamma increased the histone (H3) acetylation on the Ikaros DNA binding site. These results suggest that Ikaros acts as a negative regulator on iNOS expression. Treatment with a casein kinase 2 (CK2) inhibitor reversed LPS/IFN-gamma-induced decrease in Ikaros DNA binding activity. Moreover, overexpression of kinase-inactive CK2 decreased iNOS expression and a significant amount of CK2alpha1 translocated into the nucleus in LPS/IFN-gamma-treated cells. Overall, these data indicate that LPS/IFN-gamma decreases the Ikaros DNA binding activity via the CK2 pathway, resulting in an increase of iNOS expression.


Asunto(s)
Quinasa de la Caseína II/metabolismo , Regulación hacia Abajo , Factor de Transcripción Ikaros/metabolismo , Macrófagos/enzimología , Óxido Nítrico Sintasa de Tipo II/metabolismo , Acetilación/efectos de los fármacos , Animales , Sitios de Unión , Línea Celular , Núcleo Celular/efectos de los fármacos , Núcleo Celular/enzimología , Regulación hacia Abajo/efectos de los fármacos , Inducción Enzimática/efectos de los fármacos , Histonas/metabolismo , Interferón gamma/farmacología , Lipopolisacáridos/farmacología , Macrófagos/efectos de los fármacos , Ratones , Óxido Nítrico/biosíntesis , Óxido Nítrico Sintasa de Tipo II/biosíntesis , Óxido Nítrico Sintasa de Tipo II/genética , Fosforilación/efectos de los fármacos , Regiones Promotoras Genéticas , Unión Proteica/efectos de los fármacos , Transporte de Proteínas/efectos de los fármacos , Proteínas Recombinantes
7.
Arch Pharm Res ; 24(5): 466-71, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11693551

RESUMEN

Inflammation is a frequent radiation-induced reaction following therapeutic irradiation. Treatment of human umbilical endothelial cells (HUVEC) with gamma-irradiation (gammaIR) induces the expression of adhesion proteins such as intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin. Since the upregulation of these proteins on endothelial cell surface has been known to be associated with inflammation, interfering with the expression of adhesion molecules is an important therapeutic target. In the present study, we demonstrate that high mannuronic acid-containing alginate (HMA) inhibits gammaIR induced expression of ICAM-1, VCAM-1, and E-selectin on HUVEC in a dose dependent manner. HMA also inhibited gammaIR induced production of Nitric oxide (NO). These data suggest that HMA has therapeutic potential for the treatment of various inflammatory disorder associated with an increase of endothelial leukocyte adhesion molecules.


Asunto(s)
Moléculas de Adhesión Celular/efectos de la radiación , Endotelio Vascular/citología , Rayos gamma , Óxido Nítrico/química , Alginatos/farmacología , Moléculas de Adhesión Celular/biosíntesis , Línea Celular , Selectina E/biosíntesis , Endotelio Vascular/efectos de los fármacos , Ensayo de Inmunoadsorción Enzimática , Humanos , Indicadores y Reactivos , Molécula 1 de Adhesión Intercelular/biosíntesis , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/efectos de la radiación , Molécula 1 de Adhesión Celular Vascular/biosíntesis
8.
Protein Expr Purif ; 23(1): 38-44, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11570844

RESUMEN

An Escherichia coli expression system has been constructed for production of biologically active recombinant histone H1.5. A process of fermentation and purification method at a large scale has been developed. Recombinant histone H1.5 was released from the high density cultured cells by high-pressure homogenization. For an efficient removal of cell debris and partial purification of basic histone H1.5 in a single step, the whole cell lysates were directly loaded onto an expanded bed column packed with the strong cation exchanger (Streamline SP). Complete removal of various impurities was achieved by a combination of hydroxyapatite chromatography and the following cation exchange chromatography with high grade strong cation exchanger (POROS 20 HS), and finally endotoxins were removed by ultrafiltration using a 100-kDa cut-off membrane, which gave the level of endotoxin below 0.5 EU/mg. The molecular mass of the recombinant histone H1.5 analyzed by MALDI-TOF-MS, and the N-terminal amino acid sequences were in good agreement with the authentic histone H1.5. The whole process gave highly purified recombinant histone H1.5 at a high yield, compared to the conventional process.


Asunto(s)
Escherichia coli/química , Escherichia coli/genética , Histonas/aislamiento & purificación , Proteínas Recombinantes/aislamiento & purificación , Cromatografía Líquida de Alta Presión , Cromatografía por Intercambio Iónico , Electroforesis en Gel de Poliacrilamida , Endotoxinas/análisis , Histonas/química , Humanos , Hidroxiapatitas , Proteínas Recombinantes/química , Ultrafiltración
9.
Mol Biotechnol ; 18(3): 193-8, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11503514

RESUMEN

A magainin derivative, designated MSI-344, was produced in Escherichia coli as fusion protein, by utilizing a truncated amidophsphoribosyltransferase of E. coli as a fusion partner. Bacterial cells transformed with the gene encoding the fusion protein were grown to a high cell density and induced with isopropyl-1-thio-b-D-galatoside (IPTG) to initiate product expression. The fusion protein was accumulated into cytoplasmic inclusion body and recombinant MSI-344 was released from the fusion partner by hydroxylamine treatment. Following cleavage of the fusion protein with hydroxylamine, the released MSI-344 was purified to homogeneity by cationic exchange chromatography. The final purity was at least 95% by reversed-phase high performance liquid chromatography (RP-HPLC). Purified recombinant MSI-344 was found to be indistinguishable from the synthetic peptide determined by amino acid sequences and antimicrobial activity assay.


Asunto(s)
Antiinfecciosos/aislamiento & purificación , Oligopéptidos/aislamiento & purificación , Péptidos/aislamiento & purificación , Secuencia de Aminoácidos , Antibacterianos , Antiinfecciosos/farmacología , Bacillus subtilis/efectos de los fármacos , Cromatografía Líquida de Alta Presión/métodos , Escherichia coli/efectos de los fármacos , Vectores Genéticos , Concentración de Iones de Hidrógeno , Datos de Secuencia Molecular , Oligopéptidos/genética , Oligopéptidos/farmacología , Péptidos/genética , Péptidos/farmacología , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/aislamiento & purificación , Proteínas Recombinantes de Fusión/farmacología , Saccharomyces cerevisiae/efectos de los fármacos
10.
Mol Cells ; 11(3): 360-8, 2001 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-11459227

RESUMEN

GroEL is a major target of the immune defense in infection and seems to be negatively regulated by HrcA in gram-positive organisms. However, HrcA's mechanism has not been elucidated. To elucidate the role of groEL in Streptococcus pneumoniae, the groESL operon was cloned in Escherichia coli. The promoter region of the pneumococcal groESL operon contained a sigmaA type promoter and an inverted repeat (CIRCE). A Northern blot analysis of the groESL operon demonstrated that the groESL operon is transcribed as a bicistronic mRNA, and reached maximum expression 7.5 to 10 min after heat shock. A primer extension analysis showed a potential transcription start point at 155 bp upstream of the translation start site, preceding the groES gene. The putative negative regulator of the groEL gene, hrcA, of S. pneumoniae was recovered by PCR-based chromosomal walking from grpE locus. A sequence analysis showed a sigmaA type promoter flanked by 2 CIRCE elements. His-tagged HrcA was overexpressed as a soluble form in E. coli and bound to the CIRCE regions in the promoter of both groESL and dnaK operons in vitro. Additionally, a helix-loop helix motif, a putative DNA binding domain, was found at the C-terminal of HrcA. These results will help to determine the nature of HrcA in the groESL repression.


Asunto(s)
Proteínas Bacterianas/genética , Chaperoninas/genética , Proteínas de Escherichia coli , Regulación Bacteriana de la Expresión Génica , Streptococcus pneumoniae/genética , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , Proteínas de Unión al ADN , Proteínas HSP70 de Choque Térmico/genética , Datos de Secuencia Molecular , Operón/genética , Regiones Promotoras Genéticas/genética , ARN Mensajero/genética , Secuencias Repetitivas de Ácidos Nucleicos , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Transcripción Genética/genética
11.
Int Immunopharmacol ; 1(1): 147-54, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11367512

RESUMEN

High mannuronic acid-containing alginate (HMA) was tested to affect murine peritoneal macrophages. In the present study, we measured various functions of murine peritoneal macrophages that were isolated 20 h after intraperitoneal injection with HMA (25 and 100 mg/kg). HMA increased the number of peritoneal macrophages and phagocytosis. Macrophages from HMA-treated mice significantly inhibited growth of tumor cells compared to macrophages from control mice. In addition, supernatants from macrophages of HMA-treated mice contained nitric oxide (NO), hydrogen peroxide (H2O2) and TNF-alpha. The increased production of these cytotoxic molecules induced by HMA is consistent with tumoricidal activity of activated macrophages. Furthermore, HMA-induced tumoricidal activity was partially abrogated by anti-TNF-alpha, inhibitors of NO and the scavenger of reactive oxygen. Thus, the tumoricidal activity induced by HMA appeared to be mediated by the production of TNF-alpha, NO and H2O2. Taken together, these results suggest that HMA has the immunostimulating effect on macrophages after in vivo exposure of it.


Asunto(s)
Alginatos/farmacología , Ácidos Hexurónicos/farmacología , Macrófagos Peritoneales/efectos de los fármacos , Macrófagos Peritoneales/inmunología , Adyuvantes Inmunológicos/farmacología , Animales , Citotoxicidad Inmunológica/efectos de los fármacos , Activación de Macrófagos/efectos de los fármacos , Macrófagos Peritoneales/citología , Masculino , Ratones , Ratones Endogámicos C57BL , Fagocitosis/efectos de los fármacos , Células Tumorales Cultivadas
12.
J Acoust Soc Am ; 109(4): 1483-95, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11325120

RESUMEN

A theoretical model was developed to evaluate the reduction of structure-borne noise generated by an axially symmetric ring force which is applied on the interior of the cylindrical shell. The vibrating cylindrical shell is coated with a microvoided elastomer that is acoustically soft material designed for the reduction of the generated noise. The analytical model is a two-layer shell structure comprised of a cylindrical shell and an outer layer (coating) that is perfectly bonded to the cylindrical shell. The outer and inner surfaces of the coated shell are in contact with water and air, respectively. The analysis for this problem is based on the theory of elasticity, acoustic wave equations, and pertinent boundary conditions. Effects of various parameters such as coating thickness and material properties on the noise reductions are presented.

13.
Clin Sci (Lond) ; 100(3): 291-8, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11222115

RESUMEN

Helicobacter pylori is a major cause of gastric-associated diseases. To evaluate the efficacy of a possible vaccine antigen against H. pylori infection, the chimaeric construct adhesin--CTXA2B, derived from H. pylori adhesin genetically coupled to cholera toxin (CTX) subunits A2 and B (CTXA2B), was expressed in Escherichia coli as an insoluble recombinant chimaeric protein. The protein was then purified by denaturation, renaturation and size-exclusion chromatography. The composition of purified adhesin--CTXA2B was verified by SDS/PAGE and Western blotting with antibodies to antigenic components of adhesin and CTXB, and confirmed as a chimaeric protein with G(M1)-ganglioside binding activity and adhesin epitopes by a G(M1)-ELISA developed using antibodies to adhesin. Oral immunization of mice with adhesin--CTXA2B induced higher levels of mucosal IgA and serum IgG antibodies to H. pylori adhesin and to CTXB than in mice immunized with adhesin or CTXA2B alone. Adhesin--CTXA2B was also demonstrated to be a potential protective antigen in a mouse model of H. pylori infection. The immunization of mice with adhesin--CTXA2B protected 62.5% of mice infected with H. pylori SS1 strain, whereas adhesin immunization was not able to confer protection to mice. This protection may be correlated with high levels of mucosal IgA and serum IgG antibodies against H. pylori adhesin. Taken together, the results indicate that the genetically linked CTXA2B acts as a useful mucosal adjuvant, and that the adhesin-CTXA2B chimaeric protein could be a potential component in future H. pylori vaccine development.


Asunto(s)
Adhesinas Bacterianas/genética , Toxina del Cólera/genética , Infecciones por Helicobacter/prevención & control , Helicobacter pylori/inmunología , Inmunización/métodos , Vacunas de ADN , Animales , Cromatografía en Gel , Electroforesis en Gel de Poliacrilamida , Ensayo de Inmunoadsorción Enzimática , Escherichia coli/genética , Ratones , Ratones Endogámicos BALB C , Proteínas Recombinantes de Fusión/biosíntesis
14.
Scand J Immunol ; 52(1): 39-45, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10886782

RESUMEN

In this study we examined the ability of capsular polysaccharide type 2 (PS) from Streptococcus pnemoniae to induce secretory and cellular responses in peritoneal macrophages. Tumour cytotoxicity induced by preincubation with PS was demonstrated to be concentration-dependent. PS-induced tumouricidal activity was partially abrogated by anti-tumour necrosis factor (TNF)-alpha and inhibitor of nitric oxide, whereas anti-interferon (IFN)-alpha/beta antibody and the scavengers of reactive oxygen intermediates had no effect. In addition, supernatants from macrophages treated with PS contained TNF-alpha, and their iNOS-enzymatic activity was significantly increased. Thus, the tumouricidal activity induced by PS appeared to be mediated by the production of TNF-alpha and nitrite. Treatment of macrophages with PS increased the expression of CD14, the receptor for lipolysaccharide (LPS)/LPS-binding protein. Moreover, blocking antibody to CD14 abrogated partially TNF-alpha and nitrite induction by PS, suggesting that the PS-induced CD14 upregulation was correlated with secretion of TNF-alpha and nitrite. Taken together, these results demonstrate that PS may induce macrophage-secretory and cellular activities, in part, possibly via CD14-dependent pathway.


Asunto(s)
Cápsulas Bacterianas/química , Receptores de Lipopolisacáridos/fisiología , Activación de Macrófagos/efectos de los fármacos , Macrófagos Peritoneales/efectos de los fármacos , Polisacáridos Bacterianos/farmacología , Streptococcus pneumoniae/patogenicidad , Animales , Macrófagos Peritoneales/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Óxido Nítrico/fisiología , Factor de Necrosis Tumoral alfa/fisiología
15.
Cancer Lett ; 155(1): 9-17, 2000 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-10814874

RESUMEN

Aflatoxin B(1) (AFB(1)) is a potent hepatocarcinogen which is thought to exhibit an impairment of specific and non-specific immunity. Macrophages are responsible for non-specific immunity in host defense against tumors and microorganisms, and release a number of cytotoxic compounds, including nitric oxide (NO). We investigate whether the effect of AFB(1) on signal transduction is related to the decrease of NO production in murine peritoneal macrophages. When macrophages were stimulated with lipopolysaccharide (LPS) after AFB(1)-pretreatment, AFB1 decreased the NO production. The percentage of NO production in AFB(1)-pretreated macrophages was inversely increased by the addition of cholera toxin, phorbol 12-myrisate 13-acetate (PMA) and ionomycin. This suggests that AFB(1) affects the function of signaling constituents, including guanine nucleotide-binding protein (G protein), protein kinase C (PKC) and the calcium ion. AFB(1)-pretreatment significantly decreased PKC activity and tyrosine phosphorylation after LPS-stimulation. Taken together, these data propose that the inhibition of LPS-stimulated NO production by AFB(1) is related to the suppression of kinase-mediated intracellular signal transduction in murine peritoneal macrophages.


Asunto(s)
Aflatoxina B1/metabolismo , Macrófagos Peritoneales/enzimología , Fosfotransferasas/metabolismo , Transducción de Señal/efectos de los fármacos , Animales , Western Blotting , Calcio/metabolismo , Carcinógenos , Toxina del Cólera/farmacología , Relación Dosis-Respuesta a Droga , Proteínas de Unión al GTP/metabolismo , Ionomicina/farmacología , Ionóforos/farmacología , Iones , Lipopolisacáridos/farmacología , Masculino , Ratones , Óxido Nítrico/biosíntesis , Fosforilación/efectos de los fármacos , Proteína Quinasa C/metabolismo , Acetato de Tetradecanoilforbol/farmacología
16.
Int J Immunopharmacol ; 22(3): 237-46, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10685006

RESUMEN

Aflatoxin B(1) (AFB(1)), a potent hepatocarcinogen, has been known to impair non-specific and specific immunity. Macrophages play an important role in host defense against tumors and microorganisms and a number of compounds are implicated in macrophage cytotoxicity. Since activated by the reaction of LPS with CD14, macrophages produce nitric oxide (NO) that is a cytotoxic effector molecule in cell killing. In the present study, we investigated whether the alteration of CD14 level on macrophages by AFB(1) affects NO production in murine peritoneal macrophages. When macrophages were stimulated with LPS after AFB(1)-pretreatment, or they were co-treated with LPS and AFB(1), the NO production decreased in a dose-dependent manner. In contrast, when macrophages were post-treated with AFB(1) after LPS-stimulation, NO production was unchanged. DNA, RNA, and protein synthesis were reduced by AFB(1)-pretreatment of macrophages. The addition of anti-CD14 antibodies to the cultures decreased NO production further. FACS analysis showed that the binding of anti-CD14 antibodies to the macrophages was suppressed by AFB(1)-pretreatment followed by LPS-stimulation. However, AFB(1) does not alter the binding anti-CD14 antibodies to the macrophages without LPS-stimulation. In contrast, AFB(1) pretreatment increased an amount of CD14 released in culture medium. Taken together, these data indicate that the reduced NO production in murine peritoneal macrophages by AFB(1)-pretreatment is related to the suppressed expression of CD14 on macrophage membrane and to the increased secretion of it to culture medium after LPS-stimulation.


Asunto(s)
Aflatoxina B1/toxicidad , Receptores de Lipopolisacáridos/fisiología , Macrófagos Peritoneales/efectos de los fármacos , Óxido Nítrico/biosíntesis , Animales , Lipopolisacáridos/metabolismo , Lipopolisacáridos/farmacología , Macrófagos Peritoneales/metabolismo , Masculino , Ratones
17.
Microbiol Immunol ; 43(8): 807-12, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10524800

RESUMEN

In Streptococcus pneumoniae, heat shock induces the synthesis of 65-, 73-, and 84-kDa proteins, and ethanol shock induces a 104-kDa protein. In this study, the 65-, 84-, and 104-kDa proteins were identified as members of the GroEL, ClpL and alcohol dehydrogenase families, respectively, and the general properties of the stress response of S. pneumoniae to several other stresses were characterized. However, several stresses which are known to induce stress responses in Escherichia coli and Bacillus subtilis failed to induce any high molecular weight heat-shock proteins (HSPs) such as GroEL and DnaK homologues. A minor temperature shift from 30 to 37 C triggered induction of the homologues of DnaK and GroEL of E. coli. These features may provide a foundation for evaluating the role of heat-shock proteins relative to the physiology and pathogenesis of pneumococcus.


Asunto(s)
Proteínas Bacterianas/biosíntesis , Proteínas de Choque Térmico/biosíntesis , Streptococcus pneumoniae/metabolismo , Secuencia de Aminoácidos , Chaperonina 60/inmunología , Respuesta al Choque Térmico , Datos de Secuencia Molecular , Streptococcus pneumoniae/crecimiento & desarrollo , Streptococcus pneumoniae/fisiología , Temperatura
18.
Cancer Lett ; 140(1-2): 177-87, 1999 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-10403557

RESUMEN

We examined the ability of sulfonylurea derivative, DW2143 (4-phenyl-1-[1-(4-aminobenzoyl)-indoline-5-sulfonyl]-4,5-dihydro-2-imida zolone hydrochloride), to inhibit the growth of tumor cells in vitro and in vivo. When its anti-proliferative activities were tested on five murine tumor (B 16, Colon26, E1-4, 3LL and P388) and nine human tumor (BxPC-3, HepG2, Lovo, MCF-7, NCI-H69, SW480, WiDR, KB and KBV20C) cells of diverse tissue origins, the in vitro antitumor activities of DW2143 were comparable to those of doxorubicin against all tumor cell lines. In addition, the anti-proliferative activities of DW2143 against KBV20C, a vincristine-resistant cell line, are similar or superior to those of doxorubicin. When the in vivo antitumor activities using three murine tumor cells were tested after oral administration of DW2143, a wide range of tumor growth inhibition was observed. Tumor growth inhibition against 3LL at doses of 50 and 100 mg/kg DW2143 was 84.3% and 47.2%, respectively, which was comparable or superior to those of doxorubicin (5 mg/kg). Tumor growth inhibition of B16 at a dose of 100 mg/kg in the DW2143-treated group was 42% as compared to 54% for doxorubicin (5 mg/kg). When mice implanted with Colon26 were tested, tumor growth inhibition at a dose of 80 mg/kg DW2143 was 36% as compared with 37% for doxorubicin (5 mg/kg). Taken together, these results indicate that the novel sulfonylurea derivative, DW2143, is an attractive candidate for further development as a useful oral anticancer drug.


Asunto(s)
Antineoplásicos/uso terapéutico , Imidazoles/uso terapéutico , Neoplasias Experimentales/tratamiento farmacológico , Sulfonas/uso terapéutico , Animales , Peso Corporal/efectos de los fármacos , División Celular/efectos de los fármacos , Doxorrubicina/uso terapéutico , Evaluación Preclínica de Medicamentos , Femenino , Humanos , Concentración 50 Inhibidora , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Trasplante de Neoplasias , Neoplasias Experimentales/patología , Organismos Libres de Patógenos Específicos , Células Tumorales Cultivadas , Ensayo de Tumor de Célula Madre
19.
Arch Pharm Res ; 22(3): 267-73, 1999 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10403129

RESUMEN

In this study we examined the potential for the synergistic augmentation of the antitumor activity of inflammatory mouse peritoneal macrophages by stimulation with protein A combined with IFN-gamma. The moderate augmentative effect induced by preincubation with protein A was demonstrated to be concentration-dependent, whereas IFN-gamma had a very low activating effect. Following preincubation with both protein A and IFN-gamma, a marked enhancement of macrophage activity was noted. In addition, based on the utilization of neutralizing antibody to TNF-alpha or the inhibition of NO production, TNF-alpha and NO were proven to be involved as mediators during the activation of tumoricidal macrophages by protein A in combination with IFN-gamma. We also demonstrated that supernatants from macrophages treated with protein A plus IFN-gamma contained both TNF-alpha and NO at markedly increased levels. Thus, tumor cell lysis in the combined system was mediated via TNF-alpha or NO. These results demonstrate the synergistic effects on mouse peritoneal macrophage function of protein A in combination with IFN-gamma and suggest that combinations of such agents may serve as the basis for future in vivo immunotherapy.


Asunto(s)
Interferón gamma/inmunología , Macrófagos Peritoneales/inmunología , Proteína Estafilocócica A/inmunología , Animales , Antineoplásicos/inmunología , Pruebas Inmunológicas de Citotoxicidad , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Macrófagos Peritoneales/efectos de los fármacos , Ratones , Pruebas de Neutralización , Óxido Nítrico/análisis , Óxido Nítrico/biosíntesis , Nitritos/análisis , Células Tumorales Cultivadas , Factor de Necrosis Tumoral alfa/metabolismo
20.
Int J Immunopharmacol ; 21(1): 47-58, 1999 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10411281

RESUMEN

Aflatoxin B1 (AFB1) has been known to impair specific and nonspecific immunity. In the present study, we tested various functions of murine peritoneal macrophages that were isolated and stimulated with LPS after AFB1 (400 microg/5 ml/kg) was administered every other day for 2 weeks. AFB1 decreased phagocytosis and the production of superoxide anion (O2-) and hydrogen peroxide (H2O2), compared to those of corn oil-treated control group. In addition, the production of NO and TNF-alpha was decreased in macrophages of AFB1-treated mice. In vitro antitumor activity of in vivo AFB1-treated macrophages was reduced against target cell, L929. Taken together, these results suggested that AFBI might have the immunosuppressive effect on macrophages after in vivo exposure, which was related to the antitumor activity reduction.


Asunto(s)
Aflatoxina B1/toxicidad , Carcinógenos/toxicidad , Macrófagos Peritoneales/inmunología , Animales , Citotoxicidad Inmunológica/efectos de los fármacos , Depresión Química , Peróxido de Hidrógeno/metabolismo , Indicadores y Reactivos , Lipopolisacáridos/farmacología , Macrófagos Peritoneales/efectos de los fármacos , Masculino , Ratones , Óxido Nítrico/metabolismo , Nitroazul de Tetrazolio , Fagocitosis/efectos de los fármacos , Superóxidos/metabolismo , Factores de Tiempo , Factor de Necrosis Tumoral alfa/metabolismo
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