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1.
Womens Health Rep (New Rochelle) ; 5(1): 393-403, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39035143

RESUMEN

Introduction: Musculoskeletal injuries (MSKi) are the most common injury type experienced by first-responders and health care providers (HCPs), making them a significant threat to physical and mental well-being. Female reproductive health and injury history has been related to physical fitness in female members of the Canadian Armed Forces. This relationship has not been explored in Canadian protective services personnel (first-responders) or HCPs. Methods: Fifty-seven females employed as firefighters, paramedics, law enforcements, or HCPs completed a physical fitness protocol to assess the following: (1) muscular power (standing long jump and medicine ball throw), (2) muscular strength (4 repetition maximum (4RM) back squats and bench press), (3) muscular endurance (Biering-Sorenson test, single-leg wall sit, and push-ups), (4) flexibility (sit-and-reach), and (5) aerobic capacity (graded treadmill VO2max test). Spearman rho correlation analyses were applied to descriptive analysis, independent-samples t-test, one-way ANCOVA (adjusted by age), and chi-square test. Spearman rho correlation analyses were used to compare physical fitness results for female reproductive health history (e.g., parity status), previous MSKi, and physical activity behaviors (e.g., sports participation). A p value of <0.05 is considered significant. Results: History of childbirth, body composition, and exercise behaviors were related to physical fitness (i.e., standing long jump, Biering-Sorenson test, bench press, and back squat) in law enforcement, firefighting, paramedicine, and health care personnel. Conclusions: Physical training programs aimed at supporting parous first-responders or HCPs should emphasize lower body power, lower body strength, and upper body strength.

2.
Commun Biol ; 6(1): 598, 2023 06 02.
Artículo en Inglés | MEDLINE | ID: mdl-37268664

RESUMEN

Individuals with Alzheimer Disease who develop psychotic symptoms (AD + P) experience more rapid cognitive decline and have reduced indices of synaptic integrity relative to those without psychosis (AD-P). We sought to determine whether the postsynaptic density (PSD) proteome is altered in AD + P relative to AD-P, analyzing PSDs from dorsolateral prefrontal cortex of AD + P, AD-P, and a reference group of cognitively normal elderly subjects. The PSD proteome of AD + P showed a global shift towards lower levels of all proteins relative to AD-P, enriched for kinases, proteins regulating Rho GTPases, and other regulators of the actin cytoskeleton. We computationally identified potential novel therapies predicted to reverse the PSD protein signature of AD + P. Five days of administration of one of these drugs, the C-C Motif Chemokine Receptor 5 inhibitor, maraviroc, led to a net reversal of the PSD protein signature in adult mice, nominating it as a novel potential treatment for AD + P.


Asunto(s)
Enfermedad de Alzheimer , Trastornos Psicóticos , Ratones , Animales , Enfermedad de Alzheimer/metabolismo , Proteoma , Trastornos Psicóticos/metabolismo , Trastornos Psicóticos/psicología
3.
Nat Commun ; 12(1): 4855, 2021 08 11.
Artículo en Inglés | MEDLINE | ID: mdl-34381044

RESUMEN

The vertebrate brain consists of diverse neuronal types, classified by distinct anatomy and function, along with divergent transcriptomes and proteomes. Defining the cell-type specific neuroproteomes is important for understanding the development and functional organization of neural circuits. This task remains challenging in complex tissue, due to suboptimal protein isolation techniques that often result in loss of cell-type specific information and incomplete capture of subcellular compartments. Here, we develop a genetically targeted proximity labeling approach to identify cell-type specific subcellular proteomes in the mouse brain, confirmed by imaging, electron microscopy, and mass spectrometry. We virally express subcellular-localized APEX2 to map the proteome of direct and indirect pathway spiny projection neurons in the striatum. The workflow provides sufficient depth to uncover changes in the proteome of striatal neurons following chemogenetic activation of Gαq-coupled signaling cascades. This method enables flexible, cell-type specific quantitative profiling of subcellular proteome snapshots in the mouse brain.


Asunto(s)
Ascorbato Peroxidasas/metabolismo , Núcleo Celular/metabolismo , Cuerpo Estriado/metabolismo , Proteoma/metabolismo , Animales , Ascorbato Peroxidasas/genética , Cuerpo Estriado/citología , Citosol/metabolismo , Espectrometría de Masas , Ratones , Vías Nerviosas , Neuronas/citología , Neuronas/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Transducción de Señal , Coloración y Etiquetado , Flujo de Trabajo
4.
Mol Psychiatry ; 26(9): 5371-5388, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-33526823

RESUMEN

Schizophrenia (Sz) is a highly polygenic disorder, with common, rare, and structural variants each contributing only a small fraction of overall disease risk. Thus, there is a need to identify downstream points of convergence that can be targeted with therapeutics. Reduction of microtubule-associated protein 2 (MAP2) immunoreactivity (MAP2-IR) is present in individuals with Sz, despite no change in MAP2 protein levels. MAP2 is phosphorylated downstream of multiple receptors and kinases identified as Sz risk genes, altering its immunoreactivity and function. Using an unbiased phosphoproteomics approach, we quantified 18 MAP2 phosphopeptides, 9 of which were significantly altered in Sz subjects. Network analysis grouped MAP2 phosphopeptides into three modules, each with a distinct relationship to dendritic spine loss, synaptic protein levels, and clinical function in Sz subjects. We then investigated the most hyperphosphorylated site in Sz, phosphoserine1782 (pS1782). Computational modeling predicted phosphorylation of S1782 reduces binding of MAP2 to microtubules, which was confirmed experimentally. We generated a transgenic mouse containing a phosphomimetic mutation at S1782 (S1782E) and found reductions in basilar dendritic length and complexity along with reduced spine density. Because only a limited number of MAP2 interacting proteins have been previously identified, we combined co-immunoprecipitation with mass spectrometry to characterize the MAP2 interactome in mouse brain. The MAP2 interactome was enriched for proteins involved in protein translation. These associations were shown to be functional as overexpression of wild type and phosphomimetic MAP2 reduced protein synthesis in vitro. Finally, we found that Sz subjects with low MAP2-IR had reductions in the levels of synaptic proteins relative to nonpsychiatric control (NPC) subjects and to Sz subjects with normal and MAP2-IR, and this same pattern was recapitulated in S1782E mice. These findings suggest a new conceptual framework for Sz-that a large proportion of individuals have a "MAP2opathy"-in which MAP function is altered by phosphorylation, leading to impairments of neuronal structure, synaptic protein synthesis, and function.


Asunto(s)
Esquizofrenia , Animales , Ratones , Proteínas Asociadas a Microtúbulos/genética , Proteínas Asociadas a Microtúbulos/metabolismo , Microtúbulos/metabolismo , Neuronas/metabolismo , Fosforilación , Esquizofrenia/genética , Esquizofrenia/metabolismo
5.
Mol Psychiatry ; 20(9): 1091-100, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25330739

RESUMEN

Numerous investigations support decreased glutamatergic signaling as a pathogenic mechanism of schizophrenia, yet the molecular underpinnings for such dysregulation are largely unknown. In the post-mortem dorsolateral prefrontal cortex (DLPFC), we found striking decreases in tyrosine phosphorylation of N-methyl-D aspartate (NMDA) receptor subunit 2 (GluN2) that is critical for neuroplasticity. The decreased GluN2 activity in schizophrenia may not be because of downregulation of NMDA receptors as MK-801 binding and NMDA receptor complexes in postsynaptic density (PSD) were in fact increased in schizophrenia cases. At the postreceptor level, however, we found striking reductions in the protein kinase C, Pyk 2 and Src kinase activity that in tandem can decrease GluN2 activation. Given that Src serves as a hub of various signaling mechanisms affecting GluN2 phosphorylation, we postulated that Src hypoactivity may result from convergent alterations of various schizophrenia susceptibility pathways and thus mediate their effects on NMDA receptor signaling. Indeed, the DLPFC of schizophrenia cases exhibit increased PSD-95 and erbB4 and decreased receptor-type tyrosine-protein phosphatase-α (RPTPα) and dysbindin-1, each of which reduces Src activity via protein interaction with Src. To test genomic underpinnings for Src hypoactivity, we examined genome-wide association study results, incorporating 13 394 cases and 34 676 controls. We found no significant association of individual variants of Src and its direct regulators with schizophrenia. However, a protein-protein interaction-based network centered on Src showed significant enrichment of gene-level associations with schizophrenia compared with other psychiatric illnesses. Our results together demonstrate striking decreases in NMDA receptor signaling at the postreceptor level and propose Src as a nodal point of convergent dysregulations affecting NMDA receptor pathway via protein-protein associations.


Asunto(s)
Receptores de N-Metil-D-Aspartato/metabolismo , Esquizofrenia/genética , Esquizofrenia/metabolismo , Familia-src Quinasas/metabolismo , Animales , Encéfalo/metabolismo , Encéfalo/patología , Estudios de Casos y Controles , Regulación de la Expresión Génica , Estudio de Asociación del Genoma Completo , Humanos , Ratones , Ratones Noqueados , Plasticidad Neuronal , Fosforilación , Densidad Postsináptica/genética , Densidad Postsináptica/metabolismo , Corteza Prefrontal/metabolismo , Mapas de Interacción de Proteínas , Esquizofrenia/enzimología , Esquizofrenia/patología , Transducción de Señal , Familia-src Quinasas/genética
6.
Neuroscience ; 158(2): 642-53, 2009 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-18996445

RESUMEN

The olfactory epithelium constitutes the sole source of regenerating neural cells that can be obtained from a living human. As such, primary cultures derived from human olfactory epithelial biopsies can be utilized to study neurobiological characteristics of individuals under different conditions and disease states. Here, using such human cultures, we report in vitro generation of cells that exhibit a complex neuronal phenotype, encompassing receptors and signaling pathways pertinent to both olfaction and other aspects of CNS function. Using in situ hybridization, we demonstrate for the first time the native expression of olfactory receptors in cultured cells derived from human olfactory epithelial tissue. We further establish the presence and function of olfactory transduction molecules in these cells using immunocytochemistry, calcium imaging and molecular methods. Western blot analysis revealed the expression of neurotransmitter receptors for dopamine (D2R), 5-HT (5HT2C) and NMDA subtypes 1 and 2A/2B. Stimulation with dopamine or 5-HT enhanced receptor G protein activation in a subtype specific manner, based on 35S-guanosine triphosphate incorporation assay. Functional characteristics of the cultured cells are demonstrated through enhanced tyrosine phosphorylation of NMDAR 2A/2B and recruitment of signaling partners in response to NMDA stimulation. The array of neuronal characteristics observed here establishes that proliferating cells derived from the human olfactory epithelium differentiate in vitro to express functional and molecular attributes of mature olfactory neurons. These cultured neural cells exhibit neurotransmitter pathways important in a number of neuropsychiatric disorders. Their ready availability from living humans thus provides a new tool to link functional and molecular features of neural cells with clinical characteristics of individual living patients.


Asunto(s)
Células Epiteliales/metabolismo , Expresión Génica/fisiología , Proteínas del Tejido Nervioso/metabolismo , Mucosa Olfatoria/citología , Neuronas Receptoras Olfatorias/metabolismo , Adulto , Animales , Células Cultivadas , Dopaminérgicos/farmacología , Células Epiteliales/efectos de los fármacos , Femenino , Glicina/farmacología , Humanos , Inmunoprecipitación/métodos , Técnicas In Vitro , Masculino , Persona de Mediana Edad , Proteínas del Tejido Nervioso/genética , Proteína Marcadora Olfativa/genética , Proteína Marcadora Olfativa/metabolismo , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Receptores de N-Metil-D-Aspartato/genética , Receptores de N-Metil-D-Aspartato/metabolismo , Receptores Odorantes/genética , Receptores Odorantes/metabolismo , Receptores de Serotonina/genética , Receptores de Serotonina/metabolismo , Serotoninérgicos/farmacología , Adulto Joven
7.
Clin Genet ; 71(4): 311-9, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17470132

RESUMEN

Congenital indifference to pain (CIP) is a rare condition in which patients have severely impaired pain perception, but are otherwise essentially normal. We identified and collected DNA from individuals from nine families of seven different nationalities in which the affected individuals meet the diagnostic criteria for CIP. Using homozygosity mapping and haplotype sharing methods, we narrowed the CIP locus to chromosome 2q24-q31, a region known to contain a cluster of voltage-gated sodium channel genes. From these prioritized candidate sodium channels, we identified 10 mutations in the SCN9A gene encoding the sodium channel protein Nav1.7. The mutations completely co-segregated with the disease phenotype, and nine of these SCN9A mutations resulted in truncation and loss-of-function of the Nav1.7 channel. These genetic data further support the evidence that Nav1.7 plays an essential role in mediating pain in humans, and that SCN9A mutations identified in multiple different populations underlie CIP.


Asunto(s)
Mutación , Insensibilidad Congénita al Dolor/genética , Canales de Sodio/genética , Mapeo Cromosómico , Cromosomas Humanos Par 2/genética , Codón sin Sentido , Análisis Mutacional de ADN , Femenino , Efecto Fundador , Mutación del Sistema de Lectura , Genética de Población , Haplotipos , Humanos , Masculino , Canal de Sodio Activado por Voltaje NAV1.7 , Linaje , Eliminación de Secuencia
8.
Neuroscience ; 145(1): 42-55, 2007 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-17239545

RESUMEN

Environmental deprivation contributes in important ways to the development of a wide range of psychiatric disorders. Isolation rearing of rodents, a model for environmental deprivation in humans, consistently produces hyperlocomotion, which provides a measurable parameter to study the underlying mechanisms of early adverse psychosocial stressors. Male Sprague-Dawley rat pups were separated from dams at postnatal (PN) day 20 and reared either in groups of three or in isolation. On PN 38, locomotion was assessed in the open field. On PN 46, rats were killed and gene expression patterns examined in the medial prefrontal cortex (mPFC). Isolation-reared rats displayed increased locomotor activity and decreased resting time in the open field. Specific gene expression patterns in the mPFC were associated with both isolation rearing and hyperlocomotive behavior in the open field. Genes involved in these expression patterns included immediate early genes (IEGs) and genes that regulate cell differentiation and apoptosis. The study of these genes could provide important insights into how abnormal early psychosocial events affect brain function and behavior.


Asunto(s)
Regulación del Desarrollo de la Expresión Génica/fisiología , Genes Inmediatos-Precoces/fisiología , Locomoción/fisiología , Corteza Prefrontal/metabolismo , Aislamiento Social , Animales , Animales Recién Nacidos , Conducta Animal , Análisis por Conglomerados , Perfilación de la Expresión Génica/métodos , Masculino , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Ratas , Ratas Sprague-Dawley , Tiempo de Reacción
10.
Gene Ther ; 6(5): 922-30, 1999 May.
Artículo en Inglés | MEDLINE | ID: mdl-10505118

RESUMEN

Herpes simplex virus (HSV) is a new platform for gene therapy. We cloned the human herpesvirus HSV-1 strain F genome into a bacterial artificial chromosome (BAC) and adapted chromosomal gene replacement technology to manipulate the viral genome. This technology exploits the power of bacterial genetics and permits generation of recombinant viruses in as few as 7 days. We utilized this technology to delete the viral packaging/cleavage (pac) sites from HSV-BAC. HSV-BAC DNA is stable in bacteria and the pac-deleted HSV-BAC (p45-25) is able to package amplicon plasmid DNA as efficiently as a comparable pac-deleted HSV cosmid set when transfected into mammalian cells. Moreover, the utility of bacterial gene replacement is not limited to HSV, since most herpesviruses can be cloned as BACs. Thus, this technology will greatly facilitate genetic manipulation of all herpesviruses for their use as research tools or as vectors in gene therapy.


Asunto(s)
Eliminación de Gen , Técnicas de Transferencia de Gen , Vectores Genéticos/genética , Herpesvirus Humano 1/genética , Animales , Chlorocebus aethiops , Cromosomas Bacterianos , Genoma Viral , Mutagénesis Sitio-Dirigida , Células Vero
11.
Biochem Pharmacol ; 50(2): 235-41, 1995 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-7632168

RESUMEN

Calphostin C is an anti-tumor agent that binds to the regulatory domain of protein kinase C and inhibits the binding of phorbol dibutyrate. Recent studies suggest that there may be structural similarities between protein kinase C (PKC) and diacylglycerol kinase (DGK). Both enzymes bind diacylglycerol and phosphatidylserine, and sequencing of the 80 kDa diacylglycerol kinase shows that it contains zinc finger-like sequences, similar to those occurring in PKC. Similarities in some enzymatic properties of PKC and DGK led us to examine whether regulatory-site inhibitors of PKC also might inhibit DGK. For these studies, the membrane-bound DGK was partially purified from porcine testis membranes. Calphostin C inhibited DGK with an IC50 in the micromolar range. The inhibition of DGK by calphostin C was competitive with respect to diacylglycerol and was not affected by the presence or absence of phosphatidylserine. Other inhibitors of protein kinase C were without effect, with the exception of Adriamycin, which inhibited at millimolar concentrations. Staurosporine, which binds to the catalytic domain of protein kinase C, did not inhibit DGK. The results suggest that there are functional similarities between the substrate binding site of DGK and the regulatory site of protein kinase C.


Asunto(s)
Antibióticos Antineoplásicos/farmacología , Naftalenos/farmacología , Fosfotransferasas (Aceptor de Grupo Alcohol)/antagonistas & inhibidores , Testículo/enzimología , Alcaloides/farmacología , Animales , Sitios de Unión , Diacilglicerol Quinasa , Doxorrubicina/farmacología , Hierro/farmacología , Cinética , Masculino , Compuestos Organometálicos/farmacología , Fosfotransferasas (Aceptor de Grupo Alcohol)/química , Fosfotransferasas (Aceptor de Grupo Alcohol)/aislamiento & purificación , Proteína Quinasa C/antagonistas & inhibidores , Proteína Quinasa C/química , Estaurosporina , Porcinos
12.
Cutis ; 54(4): 275-8, 1994 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7805414

RESUMEN

A severely debilitated patient showed primary cutaneous mucormycosis with a Mucor species at a tape erosion site. The pathogenic nature and epidemiologic features of this unusual fungal infection are reviewed to emphasize its recognition in the differential diagnosis of ischemic lesions in immunocompromised patients. Iron overload may be a risk factor for mucormycosis.


Asunto(s)
Dermatomicosis/etiología , Hierro/efectos adversos , Mucormicosis/etiología , Dermatomicosis/microbiología , Femenino , Humanos , Persona de Mediana Edad , Factores de Riesgo
13.
J Appl Physiol (1985) ; 72(4): 1375-9, 1992 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-1592729

RESUMEN

Visceral movement due to impact loading is believed to play a role in the locomotor-respiratory coupling (LRC) that has been detected in a number of mammalian species. In the bird and bat species in which LRC has been described, the effect of the wing muscles on the timing of respiration appears to be a dominant influence. To test the hypothesis that LRC occurs in humans propelling wheelchairs (where there is no impact loading and the arms are used for locomotion), we studied 10 wheelchair athletes on a motorized treadmill at three speeds. Each subject's data were analyzed by spectral analysis (based on the fast Fourier transform), which detected apparent LRC (rates within 1% of a single-digit integer ratio) in 12 (40%) of the 30 test settings. However, a control analysis, in which each subject's arm-thrust rates were compared with another subject's breathing rates, revealed apparent (but false) coupling in 8 (27%), not significantly less often (using the chi 2 test). These findings appear to refute the hypothesis that LRC occurs during wheelchair propulsion. These data are consistent with the theory that the visceral piston is important to LRC and suggest that rhythmic arm movements are insufficient to induce the phenomenon in this setting.


Asunto(s)
Locomoción/fisiología , Periodicidad , Mecánica Respiratoria/fisiología , Adulto , Brazo , Fenómenos Biomecánicos , Humanos , Masculino , Modelos Biológicos , Movimiento/fisiología , Silla de Ruedas
14.
Obstet Gynecol ; 77(1): 63-8, 1991 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-1701526

RESUMEN

The sensitivity and specificity of maternal serum screening for Down syndrome with different biochemical markers were evaluated. Detection rates with different combinations of maternal serum alpha-fetoprotein (MSAFP), hCG, and unconjugated estriol (uE3) were established by retrieving and analyzing 54 serum specimens from women with confirmed Down syndrome pregnancies, compared with 657 specimens from women with normal outcomes. With a risk cutoff of 1:270 at the second trimester, the detection rate with MSAFP, hCG, and uE3 was two to three times higher than with MSAFP alone. With all three markers, the detection rate for Down syndrome increased from 50 to 77% as maternal age increased, and was 60% in a representative screened population. If uE3 was omitted, the detection rate decreased from 60 to 48%. One thousand women were screened prospectively, either with MSAFP or with all three markers prospectively, either with MSAFP or with all three markers and 4.1% with MSAFP. With the three markers, the positive predictive value for Down syndrome was 2.2% overall and as high as 5.9% in older women. Therefore, the addition of hCG and uE3 to the maternal serum screen increases the positive predictive value by 50-300%, depending on maternal age. These results confirm the efficacy of screening for Down syndrome using maternal age and three serum markers.


Asunto(s)
Síndrome de Down/diagnóstico , Estriol/sangre , Edad Materna , Embarazo de Alto Riesgo , Diagnóstico Prenatal , alfa-Fetoproteínas/análisis , Biomarcadores/sangre , Enfermedades Fetales/diagnóstico , Humanos , Valor Predictivo de las Pruebas , Estudios Prospectivos , Factores de Riesgo , Sensibilidad y Especificidad
15.
Biochem J ; 266(1): 291-9, 1990 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-2155609

RESUMEN

We investigated the diacyglycerol kinase species present in several baboon tissues using the substrates sn-1-stearoyl-2-arachidonoyl diacylglycerol and sn-1,2-didecanoyl diacylglycerol. Chromatography of octyl glucoside extracts of the baboon (Papio cynocephalus papio) tissues on hydroxyapatite columns revealed the presence of three diacylglycerol kinase species with different substrate preferences. One species markedly 'preferred' the substrate sn-1-stearoyl-2-arachidonoylglycerol, the two other species preferred sn-1,2-didecanoylglycerol. Measurement of the activity of the baboon brain diacylglycerol kinases toward diacylglycerols with a range of different fatty acid chains revealed a strict preference of the arachidonoyl diacylglycerol kinase for sn-1-acyl-2-arachidonoyl diacylglycerol, whereas the other enzymes showed no preference toward several long-chain-fatty-acid-containing diacylglycerols. The arachidonoyl diacylglycerol kinase was particularly abundant in brain and testis, whereas liver was practically devoid of this enzyme. The arachidonoyl diacylglycerol kinase from baboon brain was found to be predominantly associated with the particulate fraction and exhibited an apparent molecular mass of 130 kDa.


Asunto(s)
Isoenzimas/análisis , Fosfotransferasas/análisis , Animales , Encéfalo/enzimología , Diacilglicerol Quinasa , Diglicéridos/metabolismo , Isoenzimas/metabolismo , Riñón/enzimología , Hígado/enzimología , Masculino , Músculos/enzimología , Papio , Ácidos Fosfatidicos/metabolismo , Fosfotransferasas/metabolismo , Bazo/enzimología , Especificidad por Sustrato , Testículo/enzimología , Distribución Tisular
16.
J Biol Chem ; 263(3): 1575-83, 1988 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-2826485

RESUMEN

We studied the influence of platelet-derived growth factor (PDGF) on diacylglycerol phosphorylation in Swiss 3T3 cells. Rates of incorporation of 32P into phosphatidic acid (PA) and phosphatidylinositol (PtdIns) were determined in prelabeled cells into which sn-1,2-didecanoylglycerol (diC10) had been introduced. PDGF stimulated the formation of [32P]PA and -PtdIns from endogenous substrates but decreased the formation of [32P]PA10 and -PtdIns10. Direct measurements of diacylglycerol phosphorylation in lysates of quiescent and stimulated cells showed that PDGF stimulated the phosphorylation of endogenous diacylglycerol 2-fold in parallel with diacylglycerol accumulation but decreased by 50% the phosphorylation of diC10. Total diacylglycerol kinase activity, measured in a mixed micellar assay, was not changed by PDGF treatment. The maximum activity of diacylglycerol kinase exceeded that needed to phosphorylate all of the endogenous diacylglycerol, suggesting that the PDGF-dependent increase in diacylglycerol mass would account for the increase in PA formation. The increased mass of diacylglycerol also could explain the inhibition of diC10 phosphorylation, via substrate competition. The predominant species of endogenous diacylglycerol was 1-stearoyl-2-arachidonoyl-glycerol (18:0/20:4 diacylglycerol). In mixed micelles, the rate of phosphorylation of 18:0/20:4 diacylglycerol was 8-fold higher than that of diC10, and the 18:0/20:4 species competed with diC10 for phosphorylation. Studies showed that a membrane-bound enzyme accounted for the PDGF effect on PA formation; there was no evidence for translocation of cytosolic enzyme to the membrane. The results support these conclusions: 1) PDGF stimulates the phosphorylation of cellular diacylglycerol by promoting a transient accumulation of this lipid. 2) The stimulated phosphorylation is catalyzed by a diacylglycerol kinase that preferentially phosphorylates 18:0/20:4 diacylglycerol over diC10. 3) The diacylglycerol kinase responsible for the PDGF effect is membrane-bound.


Asunto(s)
Diglicéridos/metabolismo , Glicéridos/metabolismo , Fosfotransferasas/metabolismo , Factor de Crecimiento Derivado de Plaquetas/farmacología , Animales , Línea Celular , Diacilglicerol Quinasa , Ratones , Ácidos Fosfatidicos/metabolismo , Fosfatidilinositoles/metabolismo , Fosfatidilserinas/metabolismo , Fosforilación
17.
J Biol Chem ; 263(3): 1584-92, 1988 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-2826486

RESUMEN

The membrane-bound diacylglycerol kinase from Swiss 3T3 cells (M-DG kinase) was characterized with a mixed micellar assay system, and compared with the cytosolic diacylglycerol kinase from 3T3 cells and with the membrane-bound diacylglycerol kinase from Escherichia coli. M-DG kinase selectively phosphorylated arachidonoyl-diacylglycerols, at a rate 2- to 8-fold higher than that for other naturally occurring long-chain diacylglycerols. In contrast, the cytosolic 3T3 enzyme exhibited little or no selectivity among long-chain diacylglycerols but had higher activity with more soluble substrates such as 1,2-didecanoylglycerol. Comparison of the properties of M-DG kinase with those of the bacterial membrane-bound enzyme revealed that selectivity for arachidonoyl-diacylglycerol was unique to the mammalian enzyme. All three kinases were activated by phosphatidylserine, but activation did not alter the arachidonoyl selectivity of M-DG kinase. Phosphatidylserine activated M-DG kinase by increasing Vm and decreasing the apparent Km for diacylglycerol. High concentrations of diacylglycerol reduced the Ka for phosphatidylserine, but did not abolish the phosphatidylserine requirement for maximum activity. Examination of the thermal lability of M-DG kinase revealed that this enzyme was rapidly and selectively inactivated by preincubation with its preferred substrate. This novel effect may have obscured previous attempts to discern substrate selectivity. Taken together, the results provide evidence that M-DG kinase is an arachidonoyl-diacylglycerol kinase that may participate in the formation of arachidonoyl-enriched species of phosphatidylinositol.


Asunto(s)
Diglicéridos/metabolismo , Escherichia coli/enzimología , Glicéridos/metabolismo , Fosfotransferasas/metabolismo , Animales , Línea Celular , Citosol/enzimología , Diacilglicerol Quinasa , Activación Enzimática , Calor , Membranas/enzimología , Ratones , Fosfatidilserinas/metabolismo , Fosfolípidos/metabolismo , Fosforilación
18.
J Youth Adolesc ; 17(4): 349-69, 1988 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24277652

RESUMEN

Deviation from age-appropriate identity-developmental stage and problem drinking in 75 undergraduate women was investigated. A quantity/frequency scale assessed problem drinking. Two measures of identity, one projective and one observational, were used. May's Deprivation/Enhancement fantasy pattern measure assessed sexual identity. The College Women's Assertion Sample assessed the cognitive-style component of identity. The results supported the hypotheses that younger (freshman/sophomore) women deviating from their age-appropriate identity stage of dedifferentiation, and older (junior/senior) women deviating from their age-appropriate stage of identity integration, were significantly more likely to experience drinking problems than were women who had entered their age-appropriate identity stages. The findings support psychodynamic theories of identity development in late adolescence, and suggest that problem-drinking women in different age/ developmental stages of identity drink for different reasons and should be treated differently.

19.
J Biol Chem ; 262(3): 1105-10, 1987 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-3027078

RESUMEN

The regulation of phosphoinositide phosphorylation was studied in Swiss 3T3 cells that were stimulated by platelet-derived growth factor (PDGF). Studies with intact cells showed that the mitogen increased the incorporation of 32P into phosphatidylinositol (PtdIns), phosphatidylinositol 4-phosphate (PtdIns-P), and phosphatidylinositol 4,5-bisphosphate (PtdIns-P2) during the cell cycle, with distinct peaks of incorporation for all three phosphoinositides after 1 h, and for PtdIns and PtdIns-P2 after 20 h. Direct measurements of the activities of PtdIns kinase and PtdIns-P kinase in freeze-thawed cells revealed that the activity of PtdIns kinase was rate-limiting for the synthesis of PtdIns-P2. Maximal activities of PtdIns kinase and PtdIns-P kinase, with exogenous substrates, were unchanged during the 1st h of PDGF treatment, but doubled during the next 24 h. The increase in PtdIns kinase activity began within 2-4 h, exceeded the increase in cell protein, and was abolished by cycloheximide, which suggests that the enzyme was induced specifically in response to PDGF. The increase in activity of PtdIns-P kinase paralleled the increase in cell protein. Dose-response curves for PDGF showed that the activities of PtdIns kinase and PtdIns-P kinase at 24 h increased in proportion to the extent of mitogenic stimulation of the cells. Our results support the conclusion that the activities of PtdIns kinase and PtdIns-P kinase increase in response to PDGF, but only after several hours of cell cycle traverse.


Asunto(s)
Fosfatos de Fosfatidilinositol , Fosfatidilinositoles/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol) , Factor de Crecimiento Derivado de Plaquetas/farmacología , 1-Fosfatidilinositol 4-Quinasa , Animales , Ciclo Celular , Línea Celular , Cinética , Ratones , Ácidos Fosfatidicos/metabolismo , Fosfatidilinositol 4,5-Difosfato , Fosforilación , Fosfotransferasas/metabolismo
20.
J Appl Behav Anal ; 19(4): 337-48, 1986.
Artículo en Inglés | MEDLINE | ID: mdl-3804867

RESUMEN

We evaluated the effectiveness of a comprehensive training program for enhancing the conversational skills of socially isolated, impaired elderly nursing home residents. A multiple baseline design across behaviors was used to train four subjects (aged 87, 85, 68, and 66), on four content-related conversational components: expressing common courtesies, making positive self-disclosures, asking questions, and making interjections and acknowledgements. Training procedures included instructions, modeling, behavior rehearsal, feedback, and reinforcement. Results showed positive effects with all four subjects; in two cases, changes were significant enough to affect untrained observers' perceptions of the elders' conversational skills.


Asunto(s)
Terapia Conductista/métodos , Relaciones Interpersonales , Casas de Salud , Anciano , Femenino , Humanos , Conducta Imitativa , Masculino , Desempeño de Papel , Aislamiento Social , Teléfono
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