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1.
AIDS Care ; 35(8): 1164-1172, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-33443450

RESUMEN

Pain is a highly prevalent and burdensome symptom among people with HIV (PWH). This study aims to identify how the experience of living with HIV and chronic pain influences pain beliefs, health-seeking and pain management. Thirty-nine purposively sampled PWH with chronic pain (sample characteristics = 61% women, 79% Black, Asian and minority ethnic groups, 18% men who have sex with men, 45-54 median age category) participated in focus groups in London. Focus groups were co-facilitated with community members. Transcripts wereanalysed using a thematic approach. Findings revealed that HIV stigma, fractured care pathways, and general practitioners' lack of HIV training are barriers to supported pain management. Unaddressed pain results in poorer mental health and reduced quality of life, which has important clinical implications for HIV treatment adherence. Creating HIV-specific pain resources, activating social networks, and pain self-management techniques are potential solutions. Person-centred assessment and HIV training is needed to help clinicians identify PWH with chronic pain. Clear guidelines need to be developed to identify which health service providers are responsible for chronic pain management in PWH. This study generated a refined version of the Fear Avoidance Model that introduces a dimension of HIV-specific behaviours that impact PWHs seeking chronic pain management.


Asunto(s)
Dolor Crónico , Infecciones por VIH , Minorías Sexuales y de Género , Masculino , Humanos , Femenino , Homosexualidad Masculina , Dolor Crónico/terapia , Manejo del Dolor , Calidad de Vida , Infecciones por VIH/complicaciones , Infecciones por VIH/terapia , Infecciones por VIH/diagnóstico
2.
Transpl Infect Dis ; 17(1): 94-7, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25537527

RESUMEN

Eumycetoma is a chronic infection of the skin and subcutaneous tissue caused by filamentous fungi, which usually occurs in tropical or subtropical countries. We report a case of an immunocompromised patient presenting with presumed eumycetoma in the United States and his subsequent treatment with voriconazole. The use of voriconazole and liposomal amphotericin B halted the progression and allowed gradual resolution of the infection. The patient will require close monitoring and long-term therapy with voriconazole to obtain a clinical cure. Voriconazole and liposomal amphotericin B are potential initial treatment options, with long-term voriconazole maintenance therapy, for an Aspergillus-induced eumycetoma.


Asunto(s)
Antifúngicos/uso terapéutico , Aspergilosis/tratamiento farmacológico , Aspergillus/efectos de los fármacos , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Huésped Inmunocomprometido/inmunología , Micetoma/tratamiento farmacológico , Anciano , Anfotericina B/uso terapéutico , Aspergilosis/diagnóstico , Aspergilosis/microbiología , Hongos , Humanos , Masculino , Micetoma/diagnóstico , Micetoma/microbiología , Estados Unidos , Voriconazol/uso terapéutico
3.
Phys Rev Lett ; 104(7): 074501, 2010 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-20366890

RESUMEN

The first observation of fast and slow magnetocoriolis (MC) waves in a laboratory experiment is reported. Rotating nonaxisymmetric modes arising from a magnetized turbulent Taylor-Couette flow of liquid metal are identified as the fast and slow MC waves by the dependence of the rotation frequency on the applied field strength. The observed slow MC wave is damped but the observation provides a means for predicting the onset of the magnetorotational instability.

4.
Science ; 236(4806): 1263-8, 1987 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-2884727

RESUMEN

The use of molecular biological approaches has defined new mechanisms that store information in the mammalian nervous system. Environmental stimuli alter steady-state levels of messenger RNA species encoding neurotransmitters, thereby altering synaptic, neuronal, and network function over time. External or internal stimuli alter impulse activity, which alters membrane depolarization and selectively changes the expression of specific transmitter genes. These processes occur in diverse peripheral and central neurons, suggesting that information storage is widespread in the neuraxis. The temporal profile of any particular molecular mnemonic process is determined by specific kinetics of turnover and by the geometry of the neuron resulting in axonal transport of molecules to different synaptic arrays at different times. Generally, transmitters, the agents of millisecond-to-millisecond communication, are subject to relatively long-lasting changes in expression, ensuring that ongoing physiological function is translated into information storage.


Asunto(s)
Memoria/fisiología , Fenómenos Fisiológicos del Sistema Nervioso , Neurotransmisores/fisiología , Médula Suprarrenal/metabolismo , Animales , Encéfalo/fisiología , Sistema Nervioso/anatomía & histología , Sistema Nervioso/metabolismo , Neuronas/fisiología , Neurotransmisores/metabolismo , Sistema Nervioso Simpático/metabolismo , Sistema Nervioso Simpático/fisiología , Transcripción Genética
5.
Science ; 206(4425): 1408-10, 1979 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-228395

RESUMEN

Deproteinized skeletal muscle extracts free of major nucleotides from control and insulin-treated rats were fractionated and assayed for inhibition of protein phosphorylation by cyclic adenosine monophosphate (AMP)-dependent and -independent protein kinases. A differential effect of insulin on a particular fraction was observed on cyclic AMP-dependent protein kinase but not on cyclic AMP-independent protein kinases. This fraction that inhibited cyclic AMP-dependent protein kinase also stimulated glycogen synthase phosphoprotein phosphatase. It is proposed that this fraction may contain a mediator substance generateed in the presence of insulin.


Asunto(s)
Glucógeno Sintasa-D Fosfatasa/metabolismo , Insulina/farmacología , Músculos/efectos de los fármacos , Fosfoproteínas Fosfatasas/metabolismo , Inhibidores de Proteínas Quinasas , Animales , AMP Cíclico/metabolismo , Activación Enzimática/efectos de los fármacos , Peso Molecular , Proteínas Musculares/aislamiento & purificación , Proteínas Musculares/farmacología , Péptidos/farmacología , Ratas
6.
Br J Pharmacol ; 154(7): 1400-13, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18552866

RESUMEN

The zebrafish is a well-established model organism used in developmental biology. In the last decade, this technology has been extended to the generation of high-value knowledge on safety risks of novel drugs. Indeed, the larval zebrafish appear to combine advantages of whole organism phenotypic assays and those (rapid production of results with minimal resource engagement) of in vitro high-throughput screening techniques. Thus, if appropriately evaluated, it can offer undeniable advantages in drug discovery for identification of target and off-target effects. Here, we review some applications of zebrafish to identify potential safety liabilities, particularly before lead/candidate selection. For instance, zebrafish cardiovascular system can be used to reveal decreases in heart rate and atrial-ventricular dissociation, which may signal human ether-a-go-go-related gene (hERG) channel blockade. Another main area of interest is the CNS, where zebrafish behavioural assays have been and are further being developed into screening platforms for assessment of locomotor activity, convulsant and proconvulsant liability, cognitive impairment, drug dependence potential and impaired visual and auditory functions. Zebrafish also offer interesting possibilities for evaluating effects on bone density and gastrointestinal function. Furthermore, available knowledge of the renal system in larval zebrafish can allow identification of potential safety issues of drug candidates on this often neglected area in early development platforms. Although additional validation is certainly needed, the zebrafish is emerging as a versatile in vivo animal model to identify off-target effects that need investigation and further clarification early in the drug discovery process to reduce the current, high degree of attrition in development.


Asunto(s)
Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Modelos Animales , Pez Cebra , Animales , Sistemas de Liberación de Medicamentos , Diseño de Fármacos , Evaluación Preclínica de Medicamentos/métodos , Larva/metabolismo , Farmacología/métodos
7.
Science ; 361(6400): 406-411, 2018 07 27.
Artículo en Inglés | MEDLINE | ID: mdl-30049881

RESUMEN

Germline mutations in STK11, which encodes the tumor suppressor liver kinase B1 (LKB1), promote Peutz-Jeghers syndrome (PJS), a cancer predisposition syndrome characterized by the development of gastrointestinal (GI) polyps. Here, we report that heterozygous deletion of Stk11 in T cells (LThet mice) is sufficient to promote GI polyposis. Polyps from LThet mice, Stk11+/- mice, and human PJS patients display hallmarks of chronic inflammation, marked by inflammatory immune-cell infiltration, signal transducer and activator of transcription 3 (STAT3) activation, and increased expression of inflammatory factors associated with cancer progression [interleukin 6 (IL-6), IL-11, and CXCL2]. Targeting either T cells, IL-6, or STAT3 signaling reduced polyp growth in Stk11+/- animals. Our results identify LKB1-mediated inflammation as a tissue-extrinsic regulator of intestinal polyposis in PJS, suggesting possible therapeutic approaches by targeting deregulated inflammation in this disease.


Asunto(s)
Pólipos Adenomatosos/genética , Síndrome de Peutz-Jeghers/genética , Proteínas Serina-Treonina Quinasas/genética , Neoplasias Gástricas/genética , Linfocitos T/inmunología , Proteínas Quinasas Activadas por AMP , Pólipos Adenomatosos/inmunología , Pólipos Adenomatosos/patología , Animales , Quimiocina CXCL2/genética , Eliminación de Gen , Expresión Génica , Humanos , Inflamación/genética , Inflamación/inmunología , Inflamación/patología , Interleucina-11/genética , Interleucina-6/genética , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes , Síndrome de Peutz-Jeghers/inmunología , Síndrome de Peutz-Jeghers/patología , Factor de Transcripción STAT3/metabolismo , Transducción de Señal , Neoplasias Gástricas/inmunología , Neoplasias Gástricas/patología
8.
J Neuroimmunol ; 190(1-2): 8-17, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17714795

RESUMEN

Clusterin is a protein involved in multiple biological events, including neuronal cytoprotection, membrane recycling and regulation of complement-mediated membrane attack after injury. We investigated the effect of recombinant human clusterin in preclinical models of peripheral neuropathies. Daily treatment with clusterin accelerated the recovery of nerve motor evoked potential parameters after sciatic nerve injury. Prophylactic or therapeutic treatment of experimental autoimmune neuritis rats with clusterin also accelerated the rate of recovery from the disease, associated with remyelination of demyelinated nerve fibers. These data demonstrate that clusterin is capable of ameliorating clinical, neurophysiological and pathological signs in models of peripheral neuropathies.


Asunto(s)
Clusterina/farmacología , Factores de Crecimiento Nervioso/farmacología , Regeneración Nerviosa/efectos de los fármacos , Nervios Periféricos/efectos de los fármacos , Enfermedades del Sistema Nervioso Periférico/tratamiento farmacológico , Animales , Clusterina/inmunología , Clusterina/uso terapéutico , Citocinas/efectos de los fármacos , Citocinas/inmunología , Citocinas/metabolismo , Modelos Animales de Enfermedad , Encefalomielitis Autoinmune Experimental/tratamiento farmacológico , Encefalomielitis Autoinmune Experimental/inmunología , Encefalomielitis Autoinmune Experimental/fisiopatología , Femenino , Hipocampo/inmunología , Hipocampo/metabolismo , Hipocampo/patología , Ratones , Ratones Endogámicos C57BL , Proteína Básica de Mielina/efectos de los fármacos , Proteína Básica de Mielina/inmunología , Proteína Básica de Mielina/metabolismo , Vaina de Mielina/efectos de los fármacos , Vaina de Mielina/inmunología , Vaina de Mielina/patología , Factores de Crecimiento Nervioso/inmunología , Factores de Crecimiento Nervioso/uso terapéutico , Regeneración Nerviosa/inmunología , Neuronas/efectos de los fármacos , Neuronas/inmunología , Neuronas/patología , Técnicas de Cultivo de Órganos , Nervios Periféricos/inmunología , Nervios Periféricos/fisiopatología , Enfermedades del Sistema Nervioso Periférico/inmunología , Enfermedades del Sistema Nervioso Periférico/fisiopatología , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/farmacología , Proteínas Recombinantes/uso terapéutico , Neuropatía Ciática/tratamiento farmacológico , Neuropatía Ciática/inmunología , Neuropatía Ciática/fisiopatología , Resultado del Tratamiento
9.
Mol Cell Biol ; 11(11): 5767-80, 1991 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1656238

RESUMEN

Microscopic screening of a collection of cold-sensitive mutants of Saccharomyces cerevisiae led to the identification of a new gene, CDC55, which appears to be involved in the morphogenetic events of the cell cycle. CDC55 maps between CDC43 and CHC1 on the left arm of chromosome VII. At restrictive temperature, the original cdc55 mutant produces abnormally elongated buds and displays a delay or partial block of septation and/or cell separation. A cdc55 deletion mutant displays a cold-sensitive phenotype like that of the original isolate. Sequencing of CDC55 revealed that it encodes a protein of about 60 kDa, as confirmed by Western immunoblots using Cdc55p-specific antibodies. This protein has greater than 50% sequence identity to the B subunits of rabbit skeletal muscle type 2A protein phosphatase; the latter sequences were obtained by analysis of peptides derived from the purified protein, a polymerase chain reaction product, and cDNA clones. An extragenic suppressor of the cdc55 mutation lies in BEM2, a gene previously identified on the basis of an apparent role in bud emergence.


Asunto(s)
Proteínas de Ciclo Celular , Proteínas Fúngicas/genética , Genes Fúngicos , Fosfoproteínas Fosfatasas/genética , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Deleción Cromosómica , Mapeo Cromosómico , Cromosomas Fúngicos , Biblioteca de Genes , Genes Supresores , Genotipo , Sustancias Macromoleculares , Datos de Secuencia Molecular , Morfogénesis/genética , Músculos/enzimología , Oligonucleótidos , Fenotipo , Proteína Fosfatasa 2 , Conejos , Mapeo Restrictivo , Saccharomyces cerevisiae/citología , Saccharomyces cerevisiae/crecimiento & desarrollo , Homología de Secuencia de Ácido Nucleico
10.
Mol Cell Biol ; 21(8): 2683-94, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11283248

RESUMEN

The regulatory-targeting subunit (RGL), also called GM) of the muscle-specific glycogen-associated protein phosphatase PP1G targets the enzyme to glycogen where it modulates the activity of glycogen-metabolizing enzymes. PP1G/RGL has been postulated to play a central role in epinephrine and insulin control of glycogen metabolism via phosphorylation of RGL. To investigate the function of the phosphatase, RGL knockout mice were generated. Animals lacking RGL show no obvious defects. The RGL protein is absent from the skeletal and cardiac muscle of null mutants and present at approximately 50% of the wild-type level in heterozygotes. Both the level and activity of C1 protein are also decreased by approximately 50% in the RGL-deficient mice. In skeletal muscle, the glycogen synthase (GS) activity ratio in the absence and presence of glucose-6-phosphate is reduced from 0.3 in the wild type to 0.1 in the null mutant RGL mice, whereas the phosphorylase activity ratio in the absence and presence of AMP is increased from 0.4 to 0.7. Glycogen accumulation is decreased by approximately 90%. Despite impaired glycogen accumulation in muscle, the animals remain normoglycemic. Glucose tolerance and insulin responsiveness are identical in wild-type and knockout mice, as are basal and insulin-stimulated glucose uptakes in skeletal muscle. Most importantly, insulin activated GS in both wild-type and RGL null mutant mice and stimulated a GS-specific protein phosphatase in both groups. These results demonstrate that RGL is genetically linked to glycogen metabolism, since its loss decreases PP1 and basal GS activities and glycogen accumulation. However, PP1G/RGL is not required for insulin activation of GS in skeletal muscle, and rather another GS-specific phosphatase appears to be involved.


Asunto(s)
Glucógeno/metabolismo , Insulina/farmacología , Fosfoproteínas Fosfatasas/deficiencia , Animales , Secuencia de Bases , Cartilla de ADN/genética , Activación Enzimática/efectos de los fármacos , Femenino , Glucosa/metabolismo , Glucosa/farmacología , Glucógeno Sintasa/metabolismo , Resistencia a la Insulina , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/metabolismo , Fosfoproteínas Fosfatasas/química , Fosfoproteínas Fosfatasas/genética , Subunidades de Proteína
11.
Mol Biol Cell ; 3(6): 687-98, 1992 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-1323352

RESUMEN

Using cytostatic factor metaphase II-arrested extracts as a model system, we show that protein phosphatase 1 is regulated during early embryonic cell cycles in Xenopus. Phosphatase 1 activity peaks during interphase and decreases shortly before the onset of mitosis. A second peak of activity appears in mitosis at about the same time that cdc2 becomes active. If extracts are inhibited in S-phase with aphidicolin, then phosphatase 1 activity remains high. The activity of phosphatase 1 appears to determine the timing of exit from S-phase and entry into M-phase; inhibition of phosphatase 1 by the specific inhibitor, inhibitor 2 (Inh-2), causes premature entry into mitosis, whereas exogenously added phosphatase 1 lengthens the interphase period. Analysis of DNA synthesis in extracts treated with Inh-2, but lacking the A- and B-type cyclins, shows that phosphatase 1 is also required for the process of DNA replication. These data indicate that phosphatase 1 is a component of the signaling pathway that ensures that M-phase is not initiated until DNA synthesis is complete.


Asunto(s)
Mitosis/fisiología , Fosfoproteínas Fosfatasas/fisiología , Xenopus/embriología , Animales , Afidicolina/farmacología , ADN/biosíntesis , ADN/efectos de los fármacos , Éteres Cíclicos/farmacología , Mitosis/efectos de los fármacos , Ácido Ocadaico , Fosfoproteínas Fosfatasas/antagonistas & inhibidores , Proteína Fosfatasa 1
12.
Mar Environ Res ; 64(1): 54-78, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17306363

RESUMEN

The benthic bivalve, Anadara trapezia, was collected from a 'clean' reference site and transplanted along a suspected trace metal contamination gradient in Lake Macquarie, NSW. At monthly intervals, Zn, Se, Cd and Pb concentrations were measured in the surficial sediments and whole tissues of the cockle as well as their physiological condition (Scope for Growth). Zinc, Cd and Pb concentrations in sediments decreased together, southward, with the highest concentrations in the Cockle Bay area, suggesting that this is the main source of contamination. Zinc, Cd and Pb concentrations were near or above [ANZECC/ARMCANZ, 2000. National water quality management strategy paper 4. Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand. pp. 3.5.-1-3.5-10] sediment quality guidelines at Cockle Creek, Warners Bay and Koorooa Bay. Significant differences in trace metal concentrations could not be attributed to grain size or Fe concentration differences. Se concentrations were highest in fine grain Fe rich sediments of Whiteheads Lagoon, and likely to be associated with power generation operations. Trace metal concentrations did not vary significantly over time. Zinc, Cd and Pb concentrations in the tissues of A. trapezia followed a similar pattern to that of sediments. Zinc and Pb concentrations in cockles and sediments were highly correlated, indicating significant exposure-dose relationships. Selenium concentrations in the tissues of A. trapezia were higher after transplantation to the lake, however, Se concentrations were similar in all transplanted cockles, indicating that Se in contaminated sediments is not the major source of Se to organisms. There was a decline in the physiological condition of A. trapezia transplanted to Lake Macquarie after a 90-day-period with marked differences in clearance rates and respiration rates at some locations and absorption efficiencies at all locations. The mean Scope for Growth value at the most contaminated location, Cockle Bay, was markedly lower than at other locations. A significant Zn exposure-dose response relationship indicates that Zn bioaccumulation is occurring in response to sediment contamination. A significant Cd exposure-response relationship indicates that Cd may be influencing the health of cockles. Significant Pb exposure-dose, exposure-response and dose-response relationships indicate that Pb probably is affecting the health of cockles in Lake Macquarie. Therefore, Zn, Cd and Pb concentrations in sediments are likely to be affecting the health of cockles in Lake Macquarie.


Asunto(s)
Arcidae/fisiología , Exposición a Riesgos Ambientales , Sedimentos Geológicos/análisis , Metales Pesados/metabolismo , Selenio/fisiología , Contaminantes Químicos del Agua/metabolismo , Análisis de Varianza , Animales , Arcidae/química , Arcidae/metabolismo , Relación Dosis-Respuesta a Droga , Monitoreo del Ambiente , Metales Pesados/análisis , Nueva Gales del Sur , Selenio/análisis , Factores de Tiempo , Contaminantes Químicos del Agua/análisis
13.
IBRO Rep ; 1: 46-53, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30135927

RESUMEN

The storage and use of glycogen, the main energy reserve in the brain, is a metabolic feature of astrocytes. Glycogen synthesis is regulated by Protein Targeting to Glycogen (PTG), a member of specific glycogen-binding subunits of protein phosphatase-1 (PPP1). It positively regulates glycogen synthesis through de-phosphorylation of both glycogen synthase (activation) and glycogen phosphorylase (inactivation). In cultured astrocytes, PTG mRNA levels were previously shown to be enhanced by the neurotransmitter noradrenaline. To achieve further insight into the role of PTG in the regulation of astrocytic glycogen, its levels of expression were manipulated in primary cultures of mouse cortical astrocytes using adenovirus-mediated overexpression of tagged-PTG or siRNA to downregulate its expression. Infection of astrocytes with adenovirus led to a strong increase in PTG expression and was associated with massive glycogen accumulation (>100 fold), demonstrating that increased PTG expression is sufficient to induce glycogen synthesis and accumulation. In contrast, siRNA-mediated downregulation of PTG resulted in a 2-fold decrease in glycogen levels. Interestingly, PTG downregulation strongly impaired long-term astrocytic glycogen synthesis induced by insulin or noradrenaline. Finally, these effects of PTG downregulation on glycogen metabolism could also be observed in cultured astrocytes isolated from PTG-KO mice. Collectively, these observations point to a major role of PTG in the regulation of glycogen synthesis in astrocytes and indicate that conditions leading to changes in PTG expression will directly impact glycogen levels in this cell type.

14.
Biochim Biophys Acta ; 610(2): 400-12, 1980 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-7213633

RESUMEN

Injection of male bullheads (Ameiurus nebulosus) with estradiol induced the production of a major serum phosphoprotein of molecular weight 145,000. This protein was immunoprecipitable by antisera raised against lipovitellin from bullhead eggs and was absent from the serum of control males. Production of this serum protein coincided with changes in the liver mRNA population, which suggested that estradiol had induced the synthesis of additional mRNA sequences in the high-frequency class. Agarose gel electrophoresis in the presence of methyl mercury hydroxide showed that this mRNA population contained at least one species which was not present in the liver of uninjected males. This new RNA was the major polyadenylated species present in the total cellular RNA and its size relative to ribosomal RNAs and locust vitellogenin mRNA was estimated as 5800 nucleotides. When the liver total RNAs were translated in the mRNA-dependent rabbit reticulocyte lysate system the major translation product from the induced fish had the same molecular weight (145,000) as the serum phosphoprotein and was immunoprecipitable by antilipovitellin antisera. This translation product was not coded for by RNA from control fish. These observations are consistent with the induction of vitellogenesis by estradiol as reported in other egg-laying vertebrates and they show that bullhead vitellogenin and its mRNA are significantly smaller than their avian and amphibian counterparts.


Asunto(s)
Peces/metabolismo , Lipoproteínas/biosíntesis , ARN Mensajero/metabolismo , Vitelogeninas/biosíntesis , Animales , Pollos , Estradiol/farmacología , Femenino , Regulación de la Expresión Génica , Masculino , Peso Molecular , Hibridación de Ácido Nucleico , Especificidad de la Especie , Vitelogeninas/sangre , Xenopus
15.
Biochim Biophys Acta ; 804(2): 261-3, 1984 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-6326853

RESUMEN

Specific antibodies were used to purify glycogen synthase from isolated rabbit hepatocytes that had been incubated in a medium containing [32P]phosphate. The enzyme gave rise to two main 32P-labeled CNBr fragments of electrophoretic mobilities similar to those obtained after phosphorylation of the enzyme by individual protein kinases in vitro.


Asunto(s)
Glucógeno Sintasa/metabolismo , Hígado/enzimología , Proteínas Quinasas/metabolismo , Animales , Proteínas Quinasas Dependientes de Calcio-Calmodulina , Bromuro de Cianógeno , Fragmentos de Péptidos/análisis , Fosfopéptidos/análisis , Radioisótopos de Fósforo , Fosforilación , Conejos
16.
Biochim Biophys Acta ; 888(2): 225-36, 1986 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-3091084

RESUMEN

Rat liver glycogen synthase was purified to homogeneity by an improved procedure that yielded enzyme almost exclusively as a polypeptide of Mr 85,000. The phosphorylation of this enzyme by eight protein kinases was analyzed by cleavage of the enzyme subunit followed by mapping of the phosphopeptides using polyacrylamide gel electrophoresis in the presence of SDS, reverse-phase high-performance liquid chromatography and thin-layer electrophoresis. Cyclic AMP-dependent protein kinase, phosphorylase kinase, protein kinase C and the calmodulin-dependent protein kinase all phosphorylated the same small peptide (approx. 20 amino acids) located in a 14 kDa CNBr-fragment (CB-1). Calmodulin-dependent protein kinase and protein kinase C also modified second sites in CB-1. A larger CNBr-fragment (CB-2) of approx. 28 kDa was the dominant site of action for casein kinases I and II, FA/GSK-3 and the heparin-activated protein kinase. The sites modified were all localized in a 14 kDa species generated by trypsin digestion. Further proteolysis with V8 proteinase indicated that FA/GSK-3 and the heparin-activated enzyme recognized the same smaller peptide within CB-2, which may also be phosphorylated by casein kinase 1. Casein kinase 1 also modified a distinct peptide, as did casein kinase II. The results lead us to suggest homology to the muscle enzyme with regard to CB-1 phosphorylation and the region recognized by FA/GSK-3, which in rabbit muscle is characterized by a high density of proline and serine residues. A striking difference with the muscle isozyme is the apparent lack of phosphorylations corresponding to the muscle sites 1a and 1b. These results provide further evidence for the presence of liver- and muscle-specific glycogen synthase isozymes in the rat. That the isozymes differ subtly as to phosphorylation sites may provide a clue to the functional differences between the isozymes.


Asunto(s)
Glucógeno Sintasa/metabolismo , Hígado/enzimología , Proteínas Quinasas/metabolismo , Animales , Calmodulina/fisiología , Caseína Quinasas , Glucógeno Sintasa/aislamiento & purificación , Fragmentos de Péptidos/análisis , Fosfoproteínas/análisis , Fosfoproteínas/metabolismo , Fosforilasa Quinasa/metabolismo , Fosforilación , Proteína Quinasa C/metabolismo , Ratas
17.
Leukemia ; 13(11): 1843-52, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10557060

RESUMEN

PCR-based detection of minimal residual disease (MRD) in children with precursor B cell acute lymphoblastic leukemia (pre-B ALL) by amplification of clone-specific antigen gene rearrangements has been labor-intensive. In this study we present a simpler, yet accurate, method to assess and quantitate MRD in pediatric pre-B ALL that utilizes these markers. From the sequence of the immunoglobulin heavy chain (IgH) and T cell receptor (TcR) gene rearrangements characterized at the time of diagnosis or relapse, primers were designed and tested in a clone-specific, single-round PCR assay, then analyzed by fluorescence staining of the PCR products. The most critical step involved an adherence to a new set of guidelines for the design of clone-specific primers. Application of this method to 54 IgH and 13 TcR (nine Vdelta2Ddelta3 and four Ddelta2-Ddelta3) gene rearrangements in 47 patients resulted in an intense band within the region of the predicted molecular weight, confirming the reproducibility of the assay. Quantitative applications of the approach were examined by performing a 10-replicate limiting dilution clone-specific PCR on six diagnostic samples and an asymptotic response model of the Von Krogh form was found to fit the data well. From this model, estimation of leukemic cells of remission bone marrow samples was achieved at a detection sensitivity of 2 x 10(-6). The method is demonstrated on 18 patients whose marrows were prospectively analyzed during therapy. We conclude this methodology is useful in the quick and accurate assessment of MRD in children with pre-B ALL, and could be applied to other DNA quantitation assays.


Asunto(s)
Antígenos de Neoplasias/genética , Linfoma de Burkitt/genética , Reordenamiento Génico , Reacción en Cadena de la Polimerasa/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Secuencia de Bases , Biomarcadores de Tumor/genética , Células de la Médula Ósea/metabolismo , Linfoma de Burkitt/inmunología , Linfoma de Burkitt/patología , Linfoma de Burkitt/terapia , Niño , Ensayos Clínicos como Asunto , Células Clonales , Análisis Mutacional de ADN , Cartilla de ADN , Fluorescencia , Genes de Inmunoglobulinas/genética , Humanos , Neoplasia Residual , Leucemia-Linfoma Linfoblástico de Células Precursoras B/inmunología , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patología , Leucemia-Linfoma Linfoblástico de Células Precursoras B/terapia , Estudios Prospectivos , Receptores de Antígenos de Linfocitos T/genética , Inducción de Remisión , Sensibilidad y Especificidad
18.
J Leukoc Biol ; 62(6): 911-5, 1997 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9400834

RESUMEN

The binding and functional activity of the CC chemokines monocyte chemoattractant protein-1 (MCP-1), MCP-2, and MCP-3 have been characterized using Chinese hamster ovary DXB-11 cells transfected with the chemokine receptor CCR2B. Receptor binding studies demonstrated that 125I-labeled MCP-1 bound to a single class of high-affinity receptors with a Kd of 0.14 (0.07-0.32) nM. In competition studies MCP-1, MCP-2, and MCP-3 completely inhibited 125I-labeled MCP-1 binding with Ki values of 0.3 (0.16-0.46), 8.8 (3.4-26), and 12.2 (0.6-22) nM, respectively. In calcium mobilization studies, MCP-1 and MCP-3 induced robust elevations in intracellular calcium concentrations, whereas MCP-2 was only weakly active. In contrast, using changes in extracellular acidification rate as a functional readout, all three chemokines were identified as potent agonists of CCR2B. These data demonstrate that MCP-2, in addition to MCP-1 and MCP-3, is a potent agonist of CCR2B and furthermore that MCP-2 activates either different or a subset of the signaling pathways activated by MCP-1 and MCP-3.


Asunto(s)
Proteínas Quimioatrayentes de Monocitos/farmacología , Receptores de Quimiocina , Receptores de Citocinas/agonistas , Transducción de Señal , Animales , Células CHO , Quimiocina CCL8 , Cricetinae , Humanos , Proteínas Quimioatrayentes de Monocitos/metabolismo , Receptores CCR2 , Receptores de Citocinas/genética , Receptores de Citocinas/metabolismo , Transfección
19.
Mar Environ Res ; 59(5): 453-72, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15603769

RESUMEN

Industrial activity since the 1890s and, more recently catchment development has resulted in significant metal contamination in Lake Macquarie, an estuary in New South Wales, Australia. This paper presents an analysis of metal concentrations in surface sediments from Lake Macquarie using normalisation models to estimate enrichment relative to natural background concentrations and by comparing concentrations with sediment quality guidelines (SQGs) and effects range median quotients to assess the potential for ecological harm. Of the 12 metals examined, cadmium, lead, mercury, selenium, silver and zinc were enriched in surface sediments throughout the lake. The greatest contamination was found in the north of the lake and, for selenium, also in areas adjacent to two power stations. Comparisons with SQGs and effects range median quotients found that sediments from a site in Cockle Bay had concentrations of metals with the highest likelihood of causing adverse effects on sediment associated biota, and that the likelihood adverse decreased with distance from Cockle Bay. Comparisons with historical sediment quality data indicated that there has been a marked reduction in surface metal concentrations throughout the lake over 15 years. Models could not be constructed for all metals due to low background concentrations. For most metals, simple linear regression models were adequate, but for selenium and arsenic a multiple regression model provided a better estimate of background concentrations. SQGs possibly overestimated effects for arsenic, which has naturally high concentrations in the lake and underestimated the potential for ecological effects in coarser sediments.


Asunto(s)
Guías como Asunto , Metales Pesados/análisis , Modelos Teóricos , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente , Sedimentos Geológicos/química , Industrias , Nueva Gales del Sur , Valores de Referencia
20.
J Clin Endocrinol Metab ; 82(2): 508-13, 1997 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9024245

RESUMEN

RT-PCR analysis of total RNA prepared from the prostate cancer cell lines DU145 and PC3 and from primary epithelial cells indicated the presence of endothelin-1 (ET-1) messenger RNA (mRNA). Neither the LNCaP cell line nor primary prostatic stromal cells possess ET-1 mRNA transcripts. Seventy-two-hour-conditioned media derived from DU145, PC3, and primary epithelia contain immunoreactive ET concentrations equivalent to 0.814 +/- 0.048, 0.330 +/- 0.050, and 0.856 +/- 0.055 fmol/mL/10(6) cells after 72 h, respectively. Basal immunoreactive ET secretion was exhibited by LNCaP (0.029 +/- 0.009 fmol/mL/10(6) cells after 72 h) and stromal cells (0.067 +/- 0.007 fmol/ mL/10(6) cells after 72 h). Examination of ETA and ETB gene expression by RT-PCR demonstrates that ET receptor mRNA is almost completely undetectable in the prostate cancer cell lines. Both ETA and ETB mRNAs are detectable in primary cultures of prostatic epithelia and stroma. Competitive binding studies demonstrate a single class of binding site in both primary benign epithelia (dissociation constant = 1.85 x 10(-10) mol/L; maximal binding capacity = 2.7 x 10(4) binding sites/cell), and stroma (dissociation constant = 1.93 x 10(-10) mol/L; maximal binding capacity = 3.7 x 10(5) binding sites/cell). Use of selective ET receptor antagonists confirmed that the predominant stromal receptor subtype expressed in vitro is ETB. This receptor seems not to be coupled to mitogenic pathways because no growth response to exogenous ET-1 or cooperation between ET-1 and bFGF could be observed. Similarly, no effect of ET-1 or the ET-converting enzyme inhibitor, phosphoramidon, on benign epithelial cells could be observed over a 4-day period.


Asunto(s)
Endotelina-1/metabolismo , Próstata/metabolismo , Receptores de Endotelina/metabolismo , Unión Competitiva , División Celular/efectos de los fármacos , Células Cultivadas , Técnicas de Cultivo , Endotelina-1/genética , Endotelina-1/farmacología , Células Epiteliales , Epitelio/metabolismo , Expresión Génica , Humanos , Masculino , Próstata/citología , Células del Estroma/metabolismo
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