Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
1.
Mult Scler ; 18(8): 1116-24, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22287540

RESUMEN

BACKGROUND: Immunogenicity of recombinant interferon-ß (IFN-ß) is a known complication in the therapy of relapsing-remitting multiple sclerosis (RRMS). Neutralizing antibodies (NAbs) that can interfere with efficacy are quantified using in vitro bioassays; however, these assays do not reveal the immunogenic state of the patient and are not predictive of treatment outcome. OBJECTIVE: Assessment of the impact of NAbs on IFN-ß responsive cells and signalling pathways in peripheral blood mononuclear cells (PBMCs) with phospho-specific flow cytometry. METHOD: PBMCs from 10 IFN-ß-treated patients with RRMS, two untreated patients, and two healthy controls were re-stimulated in autologous sera and media with a serial dilution of IFN-ß (0-8000 U/ml) and levels of phosphorylation of STAT1/3/4/5/6 transcription factors were quantified in PBMC subtypes (NAb titres 0 to > 6000 neutralizing units). Data was subjected to principal component analysis, Hotelling's T (2), and partial least squares analysis. RESULTS: Three significantly distinct clusters of individuals were revealed in autologous sera: therapy-naïve and healthy, treated NAb-negative, and treated NAb-positive. Compared with controls STATs signalling patterns were modulated in treated NAb-negative patients and inhibited in all treated NAb-positive patients independently of NAb titres. In media no clustering of patients could be found. The predictability of NAb titres based on the phospho-flow data was 74%. CONCLUSION: Phospho-specific flow cytometry can delineate subset-specific cell responses that can act as surrogates for NAb exposure in blood. Immunogenic effects alter the response in primary cells even at low NAb levels. Cell line-based immunogenicity testing is not readily transferable to the immunogenic response in patients.


Asunto(s)
Anticuerpos Neutralizantes/sangre , Factores Inmunológicos/uso terapéutico , Interferón beta/uso terapéutico , Quinasas Janus/metabolismo , Leucocitos Mononucleares/efectos de los fármacos , Esclerosis Múltiple Recurrente-Remitente/tratamiento farmacológico , Factores de Transcripción STAT/metabolismo , Transducción de Señal/efectos de los fármacos , Adulto , Anciano , Estudios de Casos y Controles , Femenino , Citometría de Flujo , Humanos , Factores Inmunológicos/inmunología , Interferón beta/inmunología , Análisis de los Mínimos Cuadrados , Leucocitos Mononucleares/enzimología , Leucocitos Mononucleares/inmunología , Masculino , Persona de Mediana Edad , Esclerosis Múltiple Recurrente-Remitente/sangre , Esclerosis Múltiple Recurrente-Remitente/enzimología , Esclerosis Múltiple Recurrente-Remitente/inmunología , Noruega , Fosforilación , Análisis de Componente Principal , Proteínas Recombinantes/uso terapéutico , Resultado del Tratamiento
2.
Scand J Clin Lab Invest ; 70(1): 45-53, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20073672

RESUMEN

BACKGROUND: High-throughput technologies such as microarray have enhanced the discovery of new biomarkers in prostate cancer. However, the reliability of transcriptome analyses is limited by the RNA quality. OBJECTIVE: Identification of variables influencing the RNA quality in radical prostatectomy specimens. MATERIAL AND METHODS: RNA was extracted using an automatic extraction method for 354 samples from 38 fresh frozen prostate slices, and by manual extraction for 28 samples from 5 slices. RNA quality was measured using the RIN method (RNA Integrity Number). Evaluation of tissue composition was performed by light-microscopy for each sample. Age, total operative time, estimated blood loss, prostate volume, prostate specific antigen (s-PSA) and postoperative Gleason score were registered. The independent variables were correlated to the RIN score in a multiple linear regression model, taking p < 0.05 as the significance limit. RESULTS: The amount of blood loss during prostatectomy and the amount of stroma in the tissue sample both correlated negatively with the RIN score (p = 0.03 and 0.02). Automatically extracted samples which were exposed to heat according to the RNA extraction protocol, had lower mean RNA quality (5.5, 1.46 SD) than manually extracted samples, not exposed to heat (8.7, 0.86 SD), suggesting degradation by temperature sensitive RNases, mainly residing in the stroma. CONCLUSION: The highest RNA quality isolated by an automatic method from fresh frozen prostate tissue is obtained from patients with low peroperative blood loss and from samples with a low stromal fraction.


Asunto(s)
Próstata/química , Neoplasias de la Próstata/sangre , ARN Neoplásico/química , Anciano , Pérdida de Sangre Quirúrgica , Línea Celular Tumoral , Secciones por Congelación/métodos , Humanos , Masculino , Persona de Mediana Edad , Próstata/patología , Antígeno Prostático Específico/sangre , Prostatectomía , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/cirugía , Manejo de Especímenes
3.
Invest Ophthalmol Vis Sci ; 39(13): 2774-7, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9856789

RESUMEN

PURPOSE: To compare the amount of ascorbic acid in the corneal epithelium of various species to unveil possible differences between diurnal and nocturnal mammals. METHODS: Ascorbic acid was determined by high-performance liquid chromatography, using an LC-10 system (Shimadzu, Kyoto, Japan). RESULTS: Diurnal animals show a higher ascorbate concentration in the corneal epithelium than nocturnal animals. Ascorbate concentration is higher in the corneal epithelium than in the matching aqueous humor in diurnal and nocturnal species. The highest ascorbate concentration is found in the corneal epithelium of the reindeer. CONCLUSIONS: Ascorbate level in the corneal epithelium seems to vary in accordance with ambient radiation exposure of the respective species, just as in the aqueous humor. Both phenomena are regarded as environmental adaptations, and the ascorbic acid is suggested as protecting against photokeratitis and as acting as an ultraviolet filter for internal eye structures.


Asunto(s)
Ácido Ascórbico/análisis , Conducta Animal , Epitelio Corneal/química , Luz , Animales , Carnívoros , Gatos , Bovinos , Cromatografía Líquida de Alta Presión , Ritmo Circadiano , Ciervos , Hurones , Caballos , Ratas , Ratas Wistar , Reno , Ovinos , Porcinos
4.
Invest Ophthalmol Vis Sci ; 41(1): 20-3, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10634595

RESUMEN

PURPOSE: To analyze the ascorbate distribution in the anterior eye wall to better understand the functional significance of this compound in the eye. METHOD: Ascorbic acid was determined by high-performance liquid chromatography using an LC-10 system (Shimadzu, Kyoto, Japan). Bovine eye samples were used. RESULTS: The highest ascorbate concentration was observed in the corneal epithelium, with significantly higher values in the central (1.56 mg/g) than in the peripheral (1.39 mg/g) area. The ascorbate content was similar in the corneal stroma (0.22 mg/g), the Descemet's membrane (DM)/endothelium (0.22 mg/g), and the aqueous humor (0.21 mg/ml). By comparison, the sclera (0.15 mg/g) and the conjunctiva (0.11 mg/g) showed lower values, as did the lacrimal gland (0.09 mg/g) and the serum (0.0008 mg/ml). CONCLUSIONS: (1) Peak ascorbate concentration was observed in the central corneal epithelium covering the pupillary area. This is compatible with the idea that the ascorbate may act as an UV filter shielding internal eye structures from radiation damage. (2) The ascorbate concentration in the corneal stroma and DM/endothelium was as high as in the aqueous humor, and it is suggested that the aqueous humor plays a key role in the distribution of ascorbate to the anterior eye wall.


Asunto(s)
Segmento Anterior del Ojo/química , Ácido Ascórbico/análisis , Animales , Humor Acuoso/química , Bovinos , Cromatografía Líquida de Alta Presión , Conjuntiva/química , Sustancia Propia/química , Lámina Limitante Posterior/química , Endotelio Corneal/química , Epitelio Corneal/química , Aparato Lagrimal/química , Proyectos Piloto , Esclerótica/química
5.
Invest Ophthalmol Vis Sci ; 41(8): 2067-9, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10892844

RESUMEN

PURPOSE: To analyze the components responsible for the UV absorbance in diurnal bird aqueous humor. METHODS: The absorbance studies were carried out using a Hitachi spectrophotometer (U 2000). Uric acid was determined by high-performance liquid chromatography (LC-10 system; Shimadzu, Kyoto, Japan). Chicken and turkey eyes were examined. RESULTS: The UV absorbance in chicken aqueous was largely accounted for by the presence of protein, tryptophan, tyrosine, ascorbic acid, and uric acid. Ascorbic acid was low (23 micromol/l). Uric acid was, on the other hand, remarkably high (151 micromol/l) compared with that in mammals (cattle, 16 micromol/l). Principally the same results were obtained in chicken and turkey. CONCLUSIONS: Uric acid is a significant UV-absorbing substance in the aqueous humor of diurnal birds with its peak absorbance at 292 nm. The hypothesis that the aqueous humor acts as a UV filter seems to be valid also for the avian eye. However, in these eyes uric acid fulfills the role that ascorbic acid does in mammals.


Asunto(s)
Humor Acuoso/metabolismo , Rayos Ultravioleta , Ácido Úrico/metabolismo , Ácido Úrico/efectos de la radiación , Absorción , Animales , Ácido Ascórbico/metabolismo , Bovinos , Pollos , Cromatografía Líquida de Alta Presión , Proteínas del Ojo/metabolismo , Espectrofotometría Ultravioleta , Triptófano/metabolismo , Pavos , Tirosina/metabolismo
6.
SAR QSAR Environ Res ; 14(5-6): 349-60, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-14758979

RESUMEN

Zherlock is an open source software that provides state-of-the-art data analysis tools to the user in an intuitive and flexible way. It is a front-end to different numerical "engines" to produce a seamless integration of algorithms written in different computer languages. Of particular interest is creating an interface to high-level scientific languages such as Octave (a Matlab clone) and R (an S-PLUS clone) to enable efficient porting of new data analytical methods. Zherlock uses advanced scientific visualization tools in 2-D and 3-D and has been extended to work on virtual reality (VR) systems. Central to Zherlock is a visual programming environment (VPE) which enables diagram based programming. These diagrams consist of nodes and connection lines where each node is an operator or a method and lines describe the flow of data between nodes. A VPE is chosen for Zherlock because it forms an effective way to control the processing pipeline in complex data analyses. The VPE is similar in functionality to other programs such as IRIS Explorer, AVS or LabVIEW.


Asunto(s)
Algoritmos , Diseño de Fármacos , Programas Informáticos , Informática Médica , Análisis Multivariante , Relación Estructura-Actividad Cuantitativa
7.
Adolescence ; 27(105): 63-72, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1539502

RESUMEN

Time-use attitudes (TUA) of students contributes to our understanding of classroom behavior, but has received limited attention from investigators. This study empirically examined the major constructs or dimensions identified by other researchers (Baruch, Bruno, & Horn, 1987) of students' attitudes toward time use. Attention also was given to another dimension of TUA which has not previously been empirically explored, and to an analysis of differential developmental patterns of high school students. Three constructs of TUA were identified: passive fatalistic, egoistic, and conscientious. Several significant developmental patterns of TUA were found for males and females in Grades 8, 10, and 12.


Asunto(s)
Conducta del Adolescente , Orientación , Psicología del Adolescente , Estudiantes/psicología , Adolescente , Actitud , Femenino , Humanos , Masculino , Desarrollo de la Personalidad , Autoimagen , Factores Sexuales , Encuestas y Cuestionarios , Tiempo
8.
Acta Anaesthesiol Scand ; 44(7): 864-7, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10939700

RESUMEN

BACKGROUND: A low dose solution of adrenaline 2 microg x ml(-1), fentanyl 2 microg x ml(-1) and bupivacaine 1 mg x ml(-1) has been reported to give superior pain control when used for epidural analgesia after major surgery. The present paper describes the compounding and chemical stability of this triple-component solution during storage and use. METHODS: Sterile triple-component concentrates (11X) were diluted by the use of gas isolator technology to give ready-to-use infusion solutions. Eight solutions were analysed by reverse phase high-performance liquid chromatography (HPLC) methods, and assays were performed on 1, 45, 90 and 180 days after storage at 2-8 degrees C. After 180 days the solutions were subsequently stored at 22 degrees C for four days before they were reanalysed. HPLC quantification of adrenaline was also performed on samples from solutions given to 28 different patients. RESULTS: The concentration of adrenaline and fentanyl decreased approximately 3.5% from 1 to 180 days at 4 degrees C and four days at 22 degrees C. The corresponding figure for bupivacaine was an apparent increase by 2.4% in concentration. No absorption to the polypropylene plastic bags of fentanyl and bupivacaine was detected. None of the 28 samples derived from used infusion bags contained less than 95% of the declared content of adrenaline. CONCLUSIONS: The triple-component epidural analgesic solution remained stable during six months of cold storage, followed by four days of storage at room temperature. No significant degradation of adrenaline was observed in infusion solutions returned from the wards.


Asunto(s)
Analgesia Epidural , Analgésicos Opioides/análisis , Anestésicos Locales/análisis , Bupivacaína/análisis , Epinefrina/análisis , Fentanilo/análisis , Vasoconstrictores/análisis , Adsorción , Cromatografía Líquida de Alta Presión , Composición de Medicamentos , Embalaje de Medicamentos , Estabilidad de Medicamentos , Almacenaje de Medicamentos , Luz , Soluciones Farmacéuticas , Temperatura
9.
Appl Environ Microbiol ; 64(6): 2269-72, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9603847

RESUMEN

Six bacteriocinlike peptides (plantaricin A [PlnA], PlnE, PlnF, PlnJ, PlnK, and PlnN) produced by Lactobacillus plantarum C11 were detected by amino acid sequencing and mass spectrometry. Since purification to homogeneity was problematic, all six peptides were obtained by solid-phase peptide synthesis and were tested for bacteriocin activity. It was found that L. plantarum C11 produces two two-peptide bacteriocins (PlnEF and PlnJK); a strain-specific antagonistic activity was detected at nanomolar concentrations when PlnE and PlnF were combined and when PlnJ and PlnK were combined. Complementary peptides were at least 10(3) times more active when they were combined than when they were present individually, and optimal activity was obtained when the complementary peptides were present in approximately equal amounts. The interaction between complementary peptides was specific, since neither PlnE nor PlnF could complement PlnJ or PlnK, and none of these peptides could complement the peptides constituting the two-peptide bacteriocin lactococcin G. Interestingly, PlnA, which acts as an extracellular signal (pheromone) that triggers bacteriocin production, also possessed a strain-specific antagonistic activity. No bacteriocin activity could be detected for PlnN.


Asunto(s)
Bacteriocinas/farmacología , Lactobacillus/metabolismo , Secuencia de Aminoácidos , Bacteriocinas/genética , Bacteriocinas/aislamiento & purificación , Interacciones Farmacológicas , Genes Bacterianos , Lactobacillus/efectos de los fármacos , Lactobacillus/genética , Datos de Secuencia Molecular
10.
Phys Rev Lett ; 86(3): 402-7, 2001 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-11177841

RESUMEN

Elliptic flow from nuclear collisions is a hadronic observable sensitive to the early stages of system evolution. We report first results on elliptic flow of charged particles at midrapidity in Au+Au collisions at square root(S)NN = 130 GeV using the STAR Time Projection Chamber at the Relativistic Heavy Ion Collider. The elliptic flow signal, v2, averaged over transverse momentum, reaches values of about 6% for relatively peripheral collisions and decreases for the more central collisions. This can be interpreted as the observation of a higher degree of thermalization than at lower collision energies. Pseudorapidity and transverse momentum dependence of elliptic flow are also presented.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA