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1.
BJOG ; 125(10): 1321-1329, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-29893472

RESUMEN

OBJECTIVE: Our goal was to develop a tele-colposcopy platform for primary-care clinics to improve screening sensitivity and access. Specifically, we developed a low-cost, portable Pocket colposcope and evaluated its performance in a tertiary healthcare centre in Peru. DESIGN AND SETTING: Images of the cervix were captured with a standard-of-care and Pocket colposcope at la Liga Contra el Cáncer in Lima, Peru. POPULATION: Two hundred Peruvian women with abnormal cytology and/or human papillomavirus positivity were enrolled. METHODS: Images were collected using acetic acid and Lugol's iodine as contrast agents. Biopsies were taken as per standard-of-care procedures. MAIN OUTCOME MEASURES: After passing quality review, images from 129 women were sent to four physicians who provided a diagnosis for each image. RESULTS: Physician interpretation of images from the two colposcopes agreed 83.1% of the time. The average sensitivity and specificity of physician interpretation compared with pathology was similar for the Pocket (sensitivity = 71.2%, specificity = 57.5%) and standard-of-care (sensitivity = 79.8%, specificity = 56.6%) colposcopes. When compared with a previous study where only acetic acid was applied to the cervix, results indicated that adding Lugol's iodine as a secondary contrast agent improved the percent agreement between colposcopes for all pathological categories by up to 8.9% and the sensitivity and specificity of physician interpretation compared with pathology by over 6.0 and 9.0%, respectively. CONCLUSIONS: The Pocket colposcope performance was similar to that of a standard-of-care colposcope when used to identify precancerous and cancerous lesions using acetic acid and Lugol's iodine during colposcopy examinations in Peru. TWEETABLE ABSTRACT: The Pocket colposcope performance was similar to that of a standard-of-care colposcope when identifying cervical lesions.


Asunto(s)
Ácido Acético/farmacología , Colposcopios , Colposcopía , Detección Precoz del Cáncer/métodos , Yoduros/farmacología , Enfermedades del Cuello del Útero/diagnóstico , Adulto , Biopsia/métodos , Colposcopía/instrumentación , Colposcopía/métodos , Medios de Contraste/farmacología , Diseño de Equipo , Femenino , Humanos , Aumento de la Imagen/métodos , Persona de Mediana Edad , Perú/epidemiología , Sistemas de Atención de Punto , Atención Primaria de Salud/métodos , Enfermedades del Cuello del Útero/clasificación , Enfermedades del Cuello del Útero/epidemiología
2.
Diabet Med ; 34(10): 1340-1353, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28608570

RESUMEN

Regulatory approval of the first biosimilar insulin in Europe, LY2963016 insulin glargine (Abasaglar® ), in 2014 expanded the treatment options available to people with diabetes. As biosimilar insulin products come to market, it is important to recognize that insulin products are biologicals manufactured through complex biotechnology processes, and thus biosimilar insulins cannot be considered identical to their reference products. Strict regulatory guidelines adopted by authorities in Europe, the USA and some other countries help to ensure that efficacy and safety profiles of biosimilar insulins are not meaningfully different from those of the reference products, preventing entry of biological compounds not meeting quality standards and potentially affecting people's glycaemic outcomes. This review explains the concept of biosimilar medicines and outlines regulatory requirements for registration of biosimilar insulins in Europe, which is illustrated by the successful development of LY2963016 insulin glargine and MK-1293 insulin glargine (Lusduna® ). Preclinical and clinical comparative studies of the biosimilar insulin glargine programmes include in vitro bioassays for insulin and insulin-like growth factor 1 receptor binding, assessment of in vitro biological activity, evaluation of pharmacokinetic/pharmacodynamic profiles in phase I studies and assessment of long-term safety and efficacy in phase III studies. The emergence of biosimilar insulins may help broaden access to modern insulins, increase individualized treatment options and reduce costs of insulin therapy.


Asunto(s)
Biosimilares Farmacéuticos/uso terapéutico , Diabetes Mellitus/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Insulinas/uso terapéutico , Ensayos Clínicos como Asunto/estadística & datos numéricos , Diabetes Mellitus/epidemiología , Europa (Continente)/epidemiología , Humanos
3.
Diabetes Obes Metab ; 18(4): 425-9, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26749289

RESUMEN

The safety and efficacy of LY2963016 insulin glargine (LY IGlar) and Lantus insulin glargine (IGlar), products with identical primary amino acid sequences, were assessed in subgroups of patients with type 1 (T1D, n = 452) or type 2 diabetes (T2D, n = 299) reporting prestudy IGlar treatment in 52-week open-label (ELEMENT-1) and 24-week double-blind (ELEMENT-2) studies. At randomization, patients transitioned from their prestudy IGlar to equivalent doses of LY IGlar or IGlar. Primary efficacy (change in glycated haemoglobin from baseline to 24 weeks), other efficacy and select safety outcomes of LY IGlar were compared with those of IGlar. Continuous data were analysed using analysis of covariance, categorical data by Fisher's exact test, and treatment comparisons for hypoglycaemia by Wilcoxon test. No statistically significant treatment differences were identified for efficacy and safety outcomes except for weight change (T1D), overall incidence of detectable insulin antibodies (T2D), and serious adverse events (T2D). These differences were neither consistently observed across both studies nor observed in the total study populations, and their magnitude suggests they were not clinically meaningful. LY IGlar and IGlar show similar efficacy and safety profiles in patients reporting prestudy IGlar treatment.


Asunto(s)
Biosimilares Farmacéuticos/uso terapéutico , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hiperglucemia/prevención & control , Hipoglucemia/prevención & control , Hipoglucemiantes/uso terapéutico , Insulina Glargina/análogos & derivados , Biosimilares Farmacéuticos/efectos adversos , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 2/sangre , Método Doble Ciego , Hemoglobina Glucada/análisis , Humanos , Hipoglucemia/inducido químicamente , Hipoglucemiantes/efectos adversos , Insulina Glargina/efectos adversos , Insulina Glargina/uso terapéutico
4.
Diabetes Obes Metab ; 17(8): 726-33, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25974640

RESUMEN

AIMS: To compare the efficacy and safety of LY2963016 insulin glargine (LY IGlar) and the reference product (Lantus®) insulin glargine (IGlar) in patients with type 1 diabetes (T1D). METHODS: This phase III, randomized, open-label, 52-week study enrolled patients with T1D [glycated haemoglobin (HbA1c) ≤11%] being treated with basal (once-daily) and bolus insulin. Patients were randomized to receive once-daily LY IGlar (n = 268) or IGlar (n = 267) in combination with mealtime insulin lispro for 52 weeks. The primary efficacy outcome was to test the non-inferiority (0.4% and then 0.3% margin) of LY IGlar to IGlar as measured by change in HbA1c from baseline to 24 weeks. RESULTS: Both treatment groups had similar and significant (p < 0.001) within-group decreases in mean HbA1c values from baseline. LY IGlar met the non-inferiority criteria compared with IGlar for change in HbA1c from baseline to 24 weeks [-0.35 vs -0.46%, least-squares mean difference 0.108% (95% confidence interval -0.002 to 0.219), p > 0.05]. There were no significant (p > 0.05) treatment differences in other efficacy measures, including proportion of patients reaching HbA1c <7%, daily mean blood glucose, and insulin dose at 24 and 52 weeks. At 52 weeks, similar findings were observed between LY IGlar and IGlar for safety outcomes, including adverse events, allergic reactions, hypoglycaemia, weight change and insulin antibodies. CONCLUSIONS: Both LY IGlar and IGlar, when used in combination with mealtime insulin lispro, provided effective and similar glucose control and similar safety profiles.


Asunto(s)
Diabetes Mellitus Tipo 1/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Insulina Glargina/análogos & derivados , Insulina Glargina/uso terapéutico , Insulina Lispro/administración & dosificación , Adulto , Glucemia/efectos de los fármacos , Diabetes Mellitus Tipo 1/sangre , Esquema de Medicación , Quimioterapia Combinada/métodos , Femenino , Hemoglobina Glucada/efectos de los fármacos , Humanos , Hipoglucemia/inducido químicamente , Anticuerpos Insulínicos/sangre , Masculino , Comidas , Persona de Mediana Edad , Resultado del Tratamiento
6.
J Cell Biol ; 96(3): 920-4, 1983 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-6339524

RESUMEN

The production of laminin by early rat astrocytes in primary culture was investigated by double immunofluorescence staining for laminin and the glial fibrillary acidic protein (GFAP), a defined astrocyte marker. In early cultures (3 d in vitro; 3 DIV) cytoplasmic laminin was detected in all the GFAP-positive cells which formed the major population (80%) of the nonneuronal cells present in cultures from 20-21-d embryonic, newborn, or 5-d-old rat brains. Monensin treatment (10 microM, 4 h) resulted in accumulation of laminin in the Golgi region, located using labeled wheat germ agglutinin. Laminin started gradually to disappear from the cells with the time in culture, was absent in star-shaped, apparently mature astrocytes, but remained as pericellular matrix deposits. The disappearance of cellular laminin was dependent on the age of the animal and the time in culture so that it started earlier in cultures from 5-d-old rat brains (5 DIV) and approximately following the in vivo age difference in cultures from newborn (12 DIV) and embryonic (14 DIV) rat brains. Our results indicate that laminin is a protein of early astrocytes and also deposited by them in primary culture, thus suggesting a role for this glycoprotein in the development of the central nervous system.


Asunto(s)
Astrocitos/metabolismo , Glicoproteínas/biosíntesis , Animales , Encéfalo/crecimiento & desarrollo , Células Cultivadas , Cerebelo/citología , Cuerpo Estriado/citología , Técnica del Anticuerpo Fluorescente , Aparato de Golgi/metabolismo , Laminina , Monensina/farmacología , Ratas , Ratas Endogámicas , Sustancia Negra/citología
7.
Science ; 234(4779): 985-8, 1986 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-3775372

RESUMEN

Long-term potentiation (LTP), a long-lasting enhancement of synaptic efficacy, is considered a model for learning and memory. In anesthetized rats, activation of dentate granule cells by stimulating either the medial or lateral perforant pathway at frequencies of 100 to 400 Hz produced LTP of the stimulated pathway preferentially at 400 Hz. However, hippocampal pathways do not normally fire at this high rate. Stimuli at 200 Hz were then applied to either the medial or lateral pathway separately, to both pathways simultaneously, or to the two pathways asynchronously so that the composite stimulus applied to the granule cell dendrite was 400 Hz. LTP was produced preferentially in the asynchronous condition. Thus, lower frequency, physiological input volleys arriving asynchronously at medial and lateral synapses can induce LTP by activating a 400-Hz sensitive mechanism capable of integrating spatially separated granule cell inputs. This may reflect how LTP is normally produced in the dentate gyrus.


Asunto(s)
Hipocampo/fisiología , Animales , Estimulación Eléctrica , Potenciales Evocados , Neuronas Aferentes/fisiología , Ratas
8.
Bone Marrow Transplant ; 54(7): 987-993, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30356163

RESUMEN

Steroid-resistant (SR) acute graft-versus-host disease (aGvHD) is a life-threatening complication of allogeneic stem cell transplantation. Vedolizumab is a monoclonal antibody that impairs homing of T cells to the gastrointestinal (GI) endothelium by blocking the α4ß7 integrin. We retrospectively analyzed outcomes following vedolizumab administration for treatment of SR GI GvHD. Overall, 29 patients from three transplantation centers were included. Histopathology was available in 24 (83%) patients. The overall response rate (ORR) was 23/29 (79%); 8 (28%) patients had a complete response and 15 (52%) a partial response. Vedolizumab was administered as a 2nd-line or ≥3rd-line treatment in 13 (45%) and 16 (55%) patients, respectively. ORR in the former groups was 13/13 (100%) versus 10/16 (63%) in the latter (p = 0.012); corresponding CR rates were 7/13 (54%) versus 1/16 (6%) (p = 0.005). Early administration of vedolizumab was also associated with a greater likelihood of patients being off immunosuppression ((9/13 (69%) versus 3/16 (19%), p = 0.007) and free from fatal infectious complications (5/13 versus 14/16, p = 0.006). Overall, our data suggest that vedolizumab, especially if administered early in the disease course, may ameliorate severe SR GI aGvHD. The timing, role, and safety of vedolizumab should be further explored in prospective clinical trials.


Asunto(s)
Anticuerpos Monoclonales Humanizados/administración & dosificación , Resistencia a Medicamentos/efectos de los fármacos , Enfermedad Injerto contra Huésped , Trasplante de Células Madre Hematopoyéticas , Integrinas/antagonistas & inhibidores , Enfermedades Intestinales , Adulto , Anciano , Aloinjertos , Supervivencia sin Enfermedad , Femenino , Enfermedad Injerto contra Huésped/tratamiento farmacológico , Enfermedad Injerto contra Huésped/etiología , Enfermedad Injerto contra Huésped/mortalidad , Neoplasias Hematológicas/mortalidad , Neoplasias Hematológicas/terapia , Humanos , Enfermedades Intestinales/tratamiento farmacológico , Enfermedades Intestinales/etiología , Enfermedades Intestinales/mortalidad , Masculino , Persona de Mediana Edad , Esteroides/administración & dosificación , Tasa de Supervivencia
9.
Mol Cell Biol ; 10(3): 1265-9, 1990 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-2406566

RESUMEN

The DNA sequence of the c-myc-regulated gene mrl (G. C. Prendergast and M. D. Cole, Mol. Cell. Biol. 9:124-134, 1989) reveals that it encodes plasminogen activator inhibitor 1 (PAI-1), a regulator of extracellular proteolysis. Comparison of the human and mouse PAI-1 promoters and cDNA 3' noncoding regions revealed several highly conserved sequence domains, potential targets for c-myc and other factors influencing PAI-1 expression. We discuss possible roles for PAI-1 in normal and neoplastic cell growth control.


Asunto(s)
alfa 2-Antiplasmina/metabolismo , Animales , Secuencia de Bases , ADN/genética , Genes , Ratones , Datos de Secuencia Molecular , Regiones Promotoras Genéticas , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas c-myc , Homología de Secuencia de Ácido Nucleico
10.
Cancer Res ; 46(5): 2588-95, 1986 May.
Artículo en Inglés | MEDLINE | ID: mdl-3008994

RESUMEN

The sera of patients with small cell carcinoma of the lung (SCCL) and an associated visual paraneoplastic syndrome (VPNS) have high titer immunoglobulins that react with retinal ganglion cells and with cloned lines of the SCCL. The immunoglobulins in the sera of two patients with SCCL and VPNS reacted with at least one common antigen shared by neural cells and cloned lines of the SCCL. The molecular weights of the predominant neural and tumor antigens were 205,000, 145,000, 65,000, and 20,000-24,000 as determined by Western blots. Three of the antigens from neural tissue copurify and comigrate electrophoretically with neurofilament proteins. Polyclonal antibodies prepared against authentic neurofilament proteins react with antigens having molecular weights identical to those of proteins that react with immunoglobulins from the SCCL-VPNS patients. Polyclonal antibodies that were prepared against isolated retinal ganglion cells and that were shown previously to cause the immunoablation of the ganglion cells in vivo reacted most intensely with the Mr 205,000 antigen and weakly with the Mr 145,000 and Mr 70,000 antigens. Treatment of the Western blots with alkaline phosphatase from Escherichia coli did not affect the immunoreactivity between the immunoglobulins and the purified neurofilament proteins. It is proposed that the immunoglobulins in the sera of patients with SCCL-VPNS may be involved etiologically in the development of the VPNS.


Asunto(s)
Antígenos de Neoplasias/inmunología , Carcinoma de Células Pequeñas/inmunología , Proteínas de Filamentos Intermediarios/inmunología , Neoplasias Pulmonares/inmunología , Síndromes Paraneoplásicos/inmunología , Animales , Autoanticuerpos/inmunología , Carcinoma de Células Pequeñas/sangre , Bovinos , Oftalmopatías/inmunología , Humanos , Filamentos Intermedios/inmunología , Neoplasias Pulmonares/sangre , Peso Molecular , Proteínas de Neurofilamentos , Síndromes Paraneoplásicos/sangre , Fosfoproteínas/inmunología , Ratas , Retina/inmunología , Células Ganglionares de la Retina/inmunología , Especificidad de la Especie
11.
Biochim Biophys Acta ; 420(1): 142-54, 1976 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-2294

RESUMEN

Compared with human material glial fibrillary acidic protein isolated from bovine, rat and mouse brain was remarkably homogeneous and migrated as a single band at 54 000 mol. wt. on sodium dodecyl sulfate gel electrophoresis. The protein was extremely susceptible to proteolysis and lower molecular weight components were invariably isolated together with the major species when the brain was not rapidly frozen. Further degradation of the 54 000 mol wt. polypeptide in bovine tissues incubated at 24 degrees C resulted in preparations essentially identical to those previously isolated from human autopsy material and separating into a series of immunologically active polypeptides ranging in molecular weight from 54 000 to approximately 40 500. The gel band pattern obtained after progressively longer periods of autolysis suggested that small fragments were cleaved from the original polypeptide in successive steps of degradation. As in human brain, the lower molecular weight products in the 45 000-40 500 range were more resistant to proteolysis and still present after prolonged periods of tissue autolysis. The effect of the pH and of proteinase inhibitors on degradation was studied in homogenates of bovine brain stem incubated at 37 degrees C. At pH 8.0 PROTEOLYSIS OF The glial fibrillary acidic protein followed essentially the same pattern as in tissue. Cleavage of the major species was not prevented by the addition of proteinase inhibitors. At pH 6.0 and 6.5 a different type of degradation was observed, with rapid breakdown of the protein and loss of immunological activity. Increased solubility in buffer solutions was another effect of autolysis. Compared with cerebral cortex and brain stem, where most of the protein was water soluble, only a small fraction was extracted with buffer from bovine white matter. However, the solubility markedly increased following incubation and comparable amounts were extracted in buffer and in 6 M urea.


Asunto(s)
Química Encefálica , Proteínas del Tejido Nervioso/análisis , Neuroglía/análisis , Animales , Tronco Encefálico/análisis , Bovinos , Cerebelo/análisis , Corteza Cerebral/análisis , Electroforesis en Gel de Poliacrilamida , Concentración de Iones de Hidrógeno , Inmunodifusión , Sustancias Macromoleculares , Peso Molecular , Proteínas del Tejido Nervioso/inmunología , Ratas
12.
Biochim Biophys Acta ; 622(1): 9-17, 1980 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-6767503

RESUMEN

Antineurofilament antisera raised against chicken brain antigen were used to isolate neurofilament protein from bovine brain filament preparations by immunoaffinity chromatography. Glial fibrillary acidic protein, the subunit of glial filaments, passed unabsorbed through the column. The Mr 70 000 component of the neurofilament triplet was tightly absorbed to the column and essentially the only protein eluted at pH 2.5. The other two components of the triplet, of approximately 200 000 and 150 000 daltons, were less tightly attached to the column and eluted at pH 6.0 in 5 M urea.


Asunto(s)
Astrocitos/análisis , Axones/análisis , Citoesqueleto/análisis , Péptidos/aislamiento & purificación , Animales , Bovinos , Pollos , Cromatografía de Afinidad/métodos , Proteína Ácida Fibrilar de la Glía , Inmunodifusión , Técnicas de Inmunoadsorción , Peso Molecular , Proteínas del Tejido Nervioso/análisis
13.
Biochim Biophys Acta ; 446(1): 41-50, 1976 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-823971

RESUMEN

The purification procedure for mammalian glial fibrillary acidic protein allowed the isolation of related proteins from the brain and spinal cord of the chicken, turtle, frog and fish. With the exception of the turtle, the proteins so isolated were homogeneous and migrated as a single band on sodium dodecyl sulfate-acrylamide gel electrophoresis, displaying the same mobility as bovine glial fibrillary acidic protein, 54 000 mol. wt. In the turtle an additional slower migrating band was constantly present, together with the main species. Mammalian and submammalian proteins were similar in amino acid composition and appeared to be susceptible to the same type of in situ proteolysis, with degradation of the major species into multiple polypeptides ranging down to 40 500 mol. wt. Unless degraded, the proteins isolated from submammalian vertebrates were excluded from sodium dodecyl sulfate-acrylamide gels if a reducing agent was not added to the electrophoretic sample, thus suggesting the existance of disulfide bridges between polypeptide chains, as demonstrated for the mammalian protein. The purified submammalian antigens cross-reacted with antisera to human glial fibrillary acidic protein with formation of spurs not only at the junction between mammalian and submammalian precipitation lines, but also between submammalian lines. The antisera produced against chicken antigen did not react with the human antigen and the antichicken sera could not be absorbed with human antigen. An immunologically active cyanogen bromide peptide in the myoglobin range (17 200 mol. wt.) characteristic of the mammalian protein, degraded and nondegraded, was not present in the digest of the submammalian proteins.


Asunto(s)
Química Encefálica , Proteínas del Tejido Nervioso , Neuroglía/análisis , Médula Espinal/análisis , Aminoácidos/análisis , Animales , Pollos , Electroforesis en Gel de Poliacrilamida , Peces , Humanos , Inmunodifusión , Proteínas del Tejido Nervioso/análisis , Proteínas del Tejido Nervioso/aislamiento & purificación , Rana pipiens , Especificidad de la Especie , Tortugas
14.
Biochim Biophys Acta ; 668(2): 299-306, 1981 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-7194689

RESUMEN

This paper reports the isolation by immunoaffinity chromatography of neurofilament proteins from 1 mM sodium phosphate buffer extracts of brain, spinal cord and sciatic nerve in four mammalian species: human, bovine, rabbit and rat. Antisera were prepared against degraded chicken neurofilament proteins as previously described. The main polypeptides isolated in the fraction tightly attached to the column and eluted at pH 2.9 were at 72 and at approx. 150 kdaltons. In rat and rabbit the approx. 150-kdalton neurofilament polypeptide was apparently smaller compared with bovine and human as indicated by comigration experiments on sodium dodecyl sulfate polyacrylamide gel electrophoresis. The 200-kdalton neurofilament polypeptide was less tightly attached to the immunoaffinity column and was preferentially eluted at pH 6.0 in 5 M urea. Variable amounts of degraded products were also present in most purified preparations. Degradation was markedly increased by the omission of EDTA in the extraction and column buffers. In the rat, degraded proteins isolated on the immunoaffinity column in the absence of EDTA were at 68 and 55 kdaltons.


Asunto(s)
Química Encefálica , Citoesqueleto/análisis , Proteínas del Tejido Nervioso/aislamiento & purificación , Nervio Ciático/análisis , Médula Espinal/análisis , Animales , Bovinos , Pollos , Citoesqueleto/inmunología , Electroforesis en Gel de Poliacrilamida , Humanos , Peso Molecular , Proteínas del Tejido Nervioso/inmunología , Conejos , Ratas
15.
Biochim Biophys Acta ; 386(1): 41-51, 1975 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-804931

RESUMEN

An improved purification method for the glial fibrillary acidic protein from normal human brain is reported. Preparations of high purity were obtained by substituting DEAE and phosphocellulose chromatography with one step of hydroxylapatite chromatography. The glial fibrillary acidic protein from normal and gliosed brain was separated into 4 bands (components 1-4) ranging in molecular weight from 54 000 plus or minus 1000 to 40500 plus or minus 1000 by sodium dodecylsulfate gel electrophoresis at 7.5% and 12.5% acrylamide concentration. A better separation of the components was obtained on 12.5% acrylamide gels by increasing the time of electrophoresis to 15-17 h. In these conditions each component was split into a doublet. Preparations identical to those previously reported, i.e. 2-band preparations with an average molecular weight of 43 000, were obtained by incubating multiple sclerosis plaques at 24C for 48 h. These 2-band preparations co-migrated with the 2 lower molecular weight components (component 3, 45 000 plus or minus 1000; component 4, 40 500 plus or minus 1000) in 4-band preparations. The components cross-reacted with antisera against different preparations with an immunodiffusion pattern of complete identity and appeared to be chemically related. Most cyanogen bromide peptides were common to 2-band and 4-band preparations. A unique amino-terminal sequence of alanine-glycine-phenyl-alanine was found in all preparations, regardless of the source and of the number of components. The amino acid composition of 2-band and 4-band preparations was similar.


Asunto(s)
Química Encefálica , Proteínas del Tejido Nervioso/aislamiento & purificación , Neuroglía/análisis , Adulto , Secuencia de Aminoácidos , Aminoácidos/análisis , Animales , Cromatografía DEAE-Celulosa , Cromatografía por Intercambio Iónico , Electroforesis en Gel de Poliacrilamida , Humanos , Inmunodifusión , Masculino , Persona de Mediana Edad , Peso Molecular , Proteínas del Tejido Nervioso/análisis , Fragmentos de Péptidos/análisis , Conejos/inmunología
16.
Biochim Biophys Acta ; 578(2): 305-16, 1979 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-39623

RESUMEN

The glial fibrillary acidic protein and an immunologically active cyanogen bromide peptide were purified by immunoaffinity chromatography from 8 M urea extracts of brain filament preparations isolated from bovine white matter according to Norton's procedure. The protein accounted for approximately 30% of the total protein in this preparation and for the largest fraction in the 50 000 molecular weight range. The fraction not absorbed to the immuno-Sepharose column reacted with neurofilament antisera by double immunodiffusion. On sodium dodecyl sulfate gel electrophoresis the main bands in the non-adsorbed fraction were at 74 000 daltons and above 100 000. Several bands were seen in the 50 000 molecular weight range. It is concluded that glio- and neurofilaments co-purify together in Norton's procedure and that neurofilaments are probably heterogeneous in polypeptide composition.


Asunto(s)
Astrocitos/análisis , Química Encefálica , Citoesqueleto/análisis , Proteínas del Tejido Nervioso/aislamiento & purificación , Péptidos/aislamiento & purificación , Animales , Bovinos , Bromuro de Cianógeno , Humanos , Concentración de Iones de Hidrógeno , Inmunoquímica
17.
Biochim Biophys Acta ; 926(3): 280-6, 1987 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-2446663

RESUMEN

Ten polyclonal neurofilament antibodies were tested for domain specificity with immunoblots of chymotrypsin digests of a neurofilament protein of 150 kDa (NF 150K). In contrast to most monoclonal antibodies previously reported, the five polyclonal antibodies which showed domain specificity reacted with the 40 kDa alpha-helical rod domain of the molecule. (With one exception, monoclonal antibodies reacted with the 100 kDa carboxy-terminal peripheral domain). Of these ten polyclonal antibodies only two reacted with an isoelectric variant of NK 150K (S150) isolated by Liem and collaborators (Wong, J., Hutchison, S.B. and Liem, R.K.H. (1984) J. Biol. Chem. 259, 10867-10874) from bovine brain. 13 monoclonal antibodies were also tested for reactivity with S150 protein. With one exception, none of these antibodies reacted with this variant, not even a monoclonal antibody which we have previously shown to react with a non-phosphorylated epitope located in the rod domain of NF 150K. We suggest that either there are modifications other than dephosphorylation in the S150 isoelectric variant or, alternatively, that it is not derived from NF 150K.


Asunto(s)
Química Encefálica , Proteínas de Filamentos Intermediarios/análisis , Animales , Anticuerpos Monoclonales , Bovinos , Electroforesis en Gel de Poliacrilamida , Epítopos/análisis , Técnicas para Inmunoenzimas , Proteínas de Neurofilamentos
18.
Biochim Biophys Acta ; 790(2): 141-7, 1984 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-6435677

RESUMEN

Three bovine intermediate filament proteins, glial fibrillary acidic protein, desmin and the 70 kDa component of the neurofilament are compared by cleavage at cysteine and tryptophan. The results of these experiments show that the difference in molecular weight between the glial fibrillary acidic protein and desmin is due to a longer portion of the desmin amino terminal to the tryptophan. On the other hand, the 70 kDa protein contains a carboxy terminal addition. The tryptophan and cysteine contents of these proteins are also determined by amino-acid analysis. Differences in the apparent amount of cysteine determined by these methods in the glial fibrillary acidic protein and 70 kDa proteins are discussed. Interchain disulfide bonds result in the formation of dimers in glial fibrillary acidic protein. The bovine 70 kDa neurofilament protein and desmin also form dimers under nonreducing conditions. This emphasizes the structural similarity of these intermediate filament proteins.


Asunto(s)
Desmina , Proteína Ácida Fibrilar de la Glía , Proteínas de Filamentos Intermediarios , Animales , Bovinos , Cisteína/análisis , Desmina/aislamiento & purificación , Electroforesis en Gel de Poliacrilamida , Proteína Ácida Fibrilar de la Glía/aislamiento & purificación , Proteínas de Filamentos Intermediarios/aislamiento & purificación , Peso Molecular , Proteínas de Neurofilamentos , Fragmentos de Péptidos/análisis , Médula Espinal/análisis , Triptófano/análisis
19.
Diabetes ; 39(11): 1339-46, 1990 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-2227108

RESUMEN

In an earlier study, we described the presence of a retroendocytotic pathway for insulin in a cultured kidney epithelial cell line. Derived from the opossum kidney (OK), these cells possess many features of proximal tubule epithelium, which is the major site of kidney insulin metabolism. We studied the interaction between the retroendocytotic and the degradative pathways with bacitracin as a pharmacological probe. Monolayers of OK cells were loaded with 125I-labeled insulin over 30 min, acid washed to remove membrane-bound insulin, then incubated in fresh medium for 60 min while the release of intracellular radioactivity was monitored. In experiments carried out in the presence of bacitracin (2 mM), there was a two-thirds increase in intracellular radioactivity at the end of the loading phase. Measurements made during the subsequent release phase showed that bacitracin reduced the release of degradation products. Thus, although controls released 72.1 +/- 8.1% of the internalized radioactivity as trichloroacetic acid (TCA)-soluble products, bacitracin-treated cells released 59.2 +/- 9.4% (P less than 0.02). In contrast, release of TCA-precipitable insulin increased from 15.2 +/- 4.6% in controls to 25.8 +/- 3.7% in bacitracin-treated cells (P less than 0.01). In separate experiments analyzed by gel-exclusion chromatography, 6.4 +/- 0.6% of radioactivity released from preloaded control cells into medium over 60 min was insulin sized compared to 29.7 +/- 1.4% in bacitracin-treated cells. High-performance liquid chromatography revealed that 61.5 +/- 3.5% of this insulin-sized material released from control cells preloaded with A14-insulin eluted as intact insulin and the remainder as unidentified intermediate degradation products.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Bacitracina/farmacología , Endocitosis/efectos de los fármacos , Insulina/metabolismo , Riñón/citología , Animales , Línea Celular , Cromatografía Líquida de Alta Presión , Células Epiteliales , Epitelio/efectos de los fármacos , Riñón/efectos de los fármacos , Zarigüeyas , Receptor de Insulina/efectos de los fármacos , Receptor de Insulina/metabolismo
20.
Diabetes ; 50(11): 2579-84, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11679437

RESUMEN

An increased intramyocellular lipid (IMCL) content, as quantified by (1)H-magnetic resonance spectroscopy ((1)H-MRS), is associated with reduced insulin sensitivity. At present, it is unclear which factors determine IMCL formation and how rapidly IMCL accumulation can be induced. We therefore studied the impact of hyperinsulinemia and elevated circulating nonesterified fatty acid (NEFA) levels on IMCL formation and insulin sensitivity. We further evaluated the influence of a high-fat diet on IMCL storage. In the infusion protocol, 12 healthy male subjects underwent a 6-h hyperinsulinemic-euglycemic glucose clamp with concomitant infusion of Intralipid plus heparin. IMCL was quantified by (1)H-MRS in soleus (SOL) and tibialis anterior (TA) muscle at baseline and then every hour. IMCL levels started to increase significantly after 2 h, reaching a maximum of 120.8 +/- 3.4% (SOL) and 164.2 +/- 13.8% (TA) of baseline after 6 h (both P < 0.05). In parallel, the glucose infusion rate (GIR) decreased progressively, reaching a minimum of 60.4 +/- 5.4% of baseline after 6 h. Over time, the GIR was strongly correlated with IMCL in TA (r = -0.98, P < or = 0.003) and SOL muscle (r = -0.97, P < or = 0.005). In the diet protocol, 12 male subjects ingested both a high-fat and low-fat diet for 3 days each. Before and after completion of each diet, IMCL levels and insulin sensitivity were assessed. After the high-fat diet, IMCL levels increased significantly in TA muscle (to 148.0 +/- 16.9% of baseline; P = 0.005), but not in SOL muscle (to 114.4 +/- 8.2% of baseline; NS). Insulin sensitivity decreased to 83.3 +/- 5.6% of baseline (P = 0.033). There were no significant changes in insulin sensitivity or IMCL levels after the low-fat diet. The effects of the high-fat diet showed greater interindividual variation than those of the infusion protocol. The data from the lipid infusion protocol suggest a functional relationship between IMCL levels and insulin sensitivity. Similar effects could be induced by a high-fat diet, thereby underlining the physiological relevance of these observations.


Asunto(s)
Grasas de la Dieta/farmacología , Insulina/fisiología , Metabolismo de los Lípidos , Lípidos/farmacología , Músculo Esquelético/metabolismo , Adulto , Glucemia/análisis , Ácidos Grasos no Esterificados/sangre , Humanos , Inyecciones Intravenosas , Insulina/sangre , Masculino , Músculo Esquelético/citología
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