RESUMEN
Although childhood victimization is associated with impairments in object relations, it is not clear how different measures comparatively perform in assessing this relationship. This study examined the connection between emotional, physical, and sexual abuse in childhood and three methods of assessing malevolent object representations. Sixty adult women, recruited from an urban primary-care clinic, were administered the Thematic Apperception Test (TAT), the Object Relations Inventory (ORI) interview, and a version of the Early Memories Test (EMT)/interview. Ratings of malevolent object relations were obtained using the affect-tone dimension from the Social Cognition and Object Relations (SCORS-G) scale with both TAT and early memory narratives and through Malevolence ratings from the ORI interview. It was found that, outside of emotional abuse, ORI interview ratings of malevolence consistently differentiated adult childhood abuse groups and nonabuse groups, whereas early memory ratings of malevolence differentiated groups in two of four analyses. Malevolence ratings based upon TAT ratings failed to differentiate any type of abuse from nonabuse. These findings suggest that the use of malevolence ratings from the ORI and early memory narratives are preferred methods for assessing malevolent object relations in urban-dwelling women who have been victimized as children.
Asunto(s)
Maltrato a los Niños , Apego a Objetos , Adulto , Niño , Femenino , Humanos , Sobrevivientes , Prueba de Apercepción TemáticaRESUMEN
OBJECTIVES/HYPOTHESIS: Liquid thickeners are one of the most frequently utilized treatment strategies for persons with oropharyngeal swallowing dysfunction. The effect of commercially available thickeners on lung injury is uncertain. The purpose of this study was to compare the effects of aspiration of water alone, xanthan gum (XG)-thickened water, and cornstarch (CS)-thickened water on survival and lung morphology in a rabbit model. STUDY DESIGN: Animal model. Prospective small animal clinical trial. METHODS: Adult New Zealand White rabbits (n = 24) were divided into three groups of eight rabbits. The groups underwent 3 consecutive days of 1.5 mL/kg intratracheal instillation of water (n = 8), XG-thickened water (n = 8), and CS-thickened water (n = 8). The animals were euthanized on day 4, and survival and pulmonary histopathology were compared between groups. RESULTS: In all, 12.5% of rabbits (n = 8) instilled with CS-thickened water survived until the endpoint of the study (day 4). All animals instilled with water (n = 8) or XG-thickened water (n = 8) survived. A mild increase in intra-alveolar hemorrhage was observed for the animals instilled with CS-thickened water compared to the other groups (P < .05). In the groups that survived to the endpoint of the study, instillation of water thickened with XG resulted in greater pulmonary inflammation, pulmonary interstitial congestion, and alveolar edema than water alone (P < .05). CONCLUSIONS: These data suggest that 3 consecutive days of 1.5 mg/kg of aspirated CS-thickened water are fatal, and that XG-thickened water is more injurious than aspirated water alone. Additional research is necessary to further delineate the dangers of aspirated thickened liquids. LEVEL OF EVIDENCE: NA. Laryngoscope, 128:327-331, 2018.
Asunto(s)
Lesión Pulmonar/inducido químicamente , Pulmón/patología , Polisacáridos Bacterianos/farmacología , Almidón/farmacología , Agua/farmacología , Animales , Deglución , Trastornos de Deglución/terapia , Lesión Pulmonar/patología , Masculino , Polisacáridos Bacterianos/efectos adversos , Estudios Prospectivos , Conejos , Almidón/efectos adversos , Tasa de Supervivencia , Agua/efectos adversosRESUMEN
Activator of G protein Signaling 1 (AGS1) and Ras homologue enriched in striatum (Rhes) define a new group of Ras-like monomeric G proteins whose signaling properties and physiological roles are just beginning to be understood. Previous results suggest that AGS1 and Rhes exhibit distinct preferences for heterotrimeric G proteins, with AGS1 selectively influencing Galphai and Rhes selectively influencing Galphas. Here, we demonstrate that AGS1 and Rhes trigger nearly identical modulation of N-type Ca(2+) channels (Ca(V)2.2) by selectively altering Galphai-dependent signaling. Whole-cell currents were recorded from HEK293 cells expressing Ca(V)2.2 and Galphai- or Galphas-coupled receptors. AGS1 and Rhes reduced basal current densities and triggered tonic voltage-dependent (VD) inhibition of Ca(V)2.2. Additionally, each protein attenuated agonist-initiated channel inhibition through Galphai-coupled receptors without reducing channel inhibition through a Galphas-coupled receptor. The above effects of AGS1 and Rhes were blocked by pertussis toxin (PTX) or by expression of a Gbetagamma-sequestering peptide (masGRK3ct). Transfection with HRas, KRas2, Rap1A-G12V, Rap2B, Rheb2, or Gem failed to duplicate the effects of AGS1 and Rhes on Ca(V)2.2. Our data provide the first demonstration that AGS1 and Rhes exhibit similar if not identical signaling properties since both trigger tonic Gbetagamma signaling and both attenuate receptor-initiated signaling by the Gbetagamma subunits of PTX-sensitive G proteins. These results are consistent with the possibility that AGS1 and Rhes modulate Ca(2+) influx through Ca(V)2.2 channels under more physiological conditions and thereby influence Ca(2+)-dependent events such as neurosecretion.
Asunto(s)
Canales de Calcio Tipo N/metabolismo , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/metabolismo , Proteínas de Unión al GTP/metabolismo , Proteínas/metabolismo , Transducción de Señal , Animales , Canales de Calcio Tipo N/efectos de los fármacos , Canales de Calcio Tipo N/genética , Carbacol/farmacología , Línea Celular , Agonistas Colinérgicos/farmacología , Exodesoxirribonucleasas , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/efectos de los fármacos , Subunidades beta de la Proteína de Unión al GTP/metabolismo , Subunidades gamma de la Proteína de Unión al GTP/metabolismo , Proteínas de Unión al GTP/genética , Humanos , Potenciales de la Membrana , Toxina del Pertussis/farmacología , Fosfoproteínas , Proteínas/genética , Conejos , Receptor Muscarínico M2/agonistas , Receptor Muscarínico M2/metabolismo , Receptores Adrenérgicos beta 2/metabolismo , Transducción de Señal/efectos de los fármacos , TransfecciónRESUMEN
Neurokinin (NK) 1 receptors and CaV2.3 calcium channels are both expressed in nociceptive neurons, and mice lacking either protein display altered responses to noxious stimuli. Here, we examined modulation of CaV2.3 through NK1 receptors expressed in human embryonic kidney 293 cells. We find that NK1 receptors generate complex modulation of CaV2.3. In particular, weak activation of these receptors evokes mainly stimulation of CaV2.3, whereas strong receptor activation elicits profound inhibition that overlaps with channel stimulation. Unlike R-type channels encoded by CaV2.3, L-type (CaV1.3), N-type (CaV2.2), and P/Q-type (CaV2.1) channels are inhibited, but not stimulated, through NK1 receptors. Pharmacological experiments show that protein kinase C (PKC) mediates stimulation of CaV2.3 through NK1 receptors. The signaling mechanisms underlying inhibition were explored by expressing proteins that buffer either Galpha(q/11) (regulator of G protein signaling protein 3T and carboxyl-terminal region of phospholipase C-beta1) or Gbeta gamma subunits (transducin and the carboxyl-terminal region of bovine G-protein-coupled receptor kinase). A fast component of inhibition was attenuated by buffering Gbeta gamma, whereas a slow component of inhibition was reduced by buffering Galpha(q/11). When both Gbeta gamma and Galpha(q/11) were simultaneously buffered in the same cells, inhibition was virtually eliminated, but receptor activation still triggered substantial stimulation of CaV2.3. We also report that NK1 receptors accelerate the inactivation kinetics of CaV2.3 currents. Altogether, our results indicate that NK1 receptors modulate CaV2.3 using three different signaling mechanisms: a fast inhibition mediated by Gbeta gamma, a slow inhibition mediated by Galpha(q/11), and a slow stimulation mediated by PKC. This new information concerning R-type calcium channels and NK1 receptors may help in understanding nociception, synaptic plasticity, and other physiological processes.
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Encéfalo/fisiología , Canales de Calcio Tipo R/fisiología , Proteínas de Transporte de Catión/fisiología , Receptores de Neuroquinina-1/fisiología , Animales , Canales de Calcio Tipo R/genética , Proteínas de Transporte de Catión/genética , Línea Celular , Electrofisiología , Subunidades alfa de la Proteína de Unión al GTP Gq-G11/metabolismo , Subunidades beta de la Proteína de Unión al GTP/metabolismo , Humanos , Riñón , Cinética , Potenciales de la Membrana , Técnicas de Placa-Clamp , Plásmidos , Proteína Quinasa C/metabolismo , Conejos , Proteínas Recombinantes/metabolismo , TransfecciónRESUMEN
Ca(2+) influx through voltage-gated R-type (Ca(V)2.3) Ca(2+) channels is important for hormone and neurotransmitter secretion and other cellular events. Previous studies have shown that Ca(V)2.3 is both inhibited and stimulated through signaling mechanisms coupled to muscarinic ACh receptors. We previously demonstrated that muscarinic stimulation of Ca(V)2.3 is blocked by regulator of G protein signaling (RGS) 2. Here we investigated whether muscarinic inhibition of Ca(V)2.3 is antagonized by RGS3. RGS3 is particularly interesting because it contains a lengthy ( approximately 380 residue) amino-terminal domain of uncertain physiological function. Ca(V)2.3, M(2) muscarinic ACh receptors (M(2)R), and various deletion mutants of RGS3, including its native isoform RGS3T, were expressed in HEK293 cells, and agonist-dependent inhibition of Ca(V)2.3 was quantified using whole cell patch-clamp recordings. Full-length RGS3, RGS3T, and the core domain of RGS3 were equally effective in antagonizing inhibition of Ca(V)2.3 through M(2)R. These results identify RGS3 and RGS3T as potential physiological regulators of R-type Ca(2+) channels. Furthermore, they suggest that the signaling activity of RGS3 is unaffected by its extended amino-terminal domain. Confocal microscopy was used to examine the intracellular locations of four RGS3-enhanced green fluorescent protein fusion proteins. The RGS3 core domain was uniformly distributed throughout both cytoplasm and nucleus. By contrast, full-length RGS3, RGS3T, and the amino-terminal domain of RGS3 were restricted to the cytoplasm. These observations suggest that the amino terminus of RGS3 may serve to confine it to the cytoplasmic compartment where it can interact with cell surface receptors, heterotrimeric G proteins, and other signaling proteins.
Asunto(s)
Canales de Calcio Tipo R/metabolismo , Proteínas de Transporte de Catión/antagonistas & inhibidores , Proteínas de Transporte de Catión/metabolismo , Proteínas de Unión al GTP/fisiología , Proteínas Activadoras de GTPasa/fisiología , Receptor Muscarínico M2/antagonistas & inhibidores , Receptor Muscarínico M2/fisiología , Canales de Calcio Tipo R/fisiología , Proteínas de Transporte de Catión/fisiología , Línea Celular , Citoplasma/metabolismo , Conductividad Eléctrica , Proteínas de Unión al GTP/química , Proteínas de Unión al GTP/metabolismo , Proteínas Activadoras de GTPasa/química , Proteínas Activadoras de GTPasa/metabolismo , Humanos , Técnicas de Placa-Clamp , Isoformas de Proteínas/fisiología , Proteínas RGS , Transducción de Señal/fisiología , Distribución TisularRESUMEN
Ca(2+) influx through L-type channels is critical for numerous physiological functions. Relatively little is known about modulation of neuronal L-type Ca(2+) channels. We studied modulation of neuronal Ca(V)1.2c channels heterologously expressed in HEK293 cells with each of the known muscarinic acetylcholine receptor subtypes. Galphaq/11-coupled M1, M3, and M5 receptors each produced robust inhibition of Ca(V)1.2c, whereas Galphai/o-coupled M2 and M4 receptors were ineffective. Channel inhibition through M1 receptors was studied in detail and was found to be kinetically slow, voltage-independent, and pertussis toxin-insensitive. Slow inhibition of Ca(V)1.2c was blocked by coexpressing RGS2 or RGS3T or by intracellular dialysis with antibodies directed against Galphaq/11. In contrast, inhibition was not reduced by coexpressing betaARK1ct or Galphat. These results indicate that slow inhibition required signaling by Galphaq/11, but not Gbetagamma, subunits. Slow inhibition did not require Ca(2+) transients or Ca(2+) influx through Ca(V)1.2c channels. Additionally, slow inhibition was insensitive to pharmacological inhibitors of phospholipases, protein kinases, and protein phosphatases. Intracellular BAPTA prevented slow inhibition via a mechanism other than Ca(2+) chelation. The cardiac splice-variant of Ca(V)1.2 (Ca(V)1.2a) and a splice-variant of the neuronal/neuroendocrine Ca(V)1.3 channel also appeared to undergo slow muscarinic inhibition. Thus, slow muscarinic inhibition may be a general characteristic of L-type channels having widespread physiological significance.