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1.
Front Immunol ; 15: 1305587, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38487530

RESUMO

Maternal immunoglobulin transfer plays a key role in conferring passive immunity to neonates. Maternal blood immunoglobulin Y (IgY) in avian species is transported to newly-hatched chicks in two steps: 1) IgY is transported from the maternal circulation to the yolk of maturing oocytes, 2) the IgY deposited in yolk is transported to the circulation of the embryo via the yolk sac membrane. An IgY-Fc receptor, FcRY, is involved in the second step, but the mechanism of the first step is still unclear. We determined whether FcRY was also the basis for maternal blood IgY transfer to the yolk in the first step during egg development. Immunohistochemistry revealed that FcRY was expressed in the capillary endothelial cells in the internal theca layer of the ovarian follicle. Substitution of the amino acid residue in Fc region of IgY substantially changed the transport efficiency of IgY into egg yolks when intravenously-injected into laying quail; the G365A mutant had a high transport efficiency, but the Y363A mutant lacked transport ability. Binding analyses of IgY mutants to FcRY indicated that the mutant with a high transport efficiency (G365A) had a strong binding activity to FcRY; the mutants with a low transport efficiency (G365D, N408A) had a weak binding activity to FcRY. One exception, the Y363A mutant had a remarkably strong binding affinity to FcRY, with a small dissociation rate. The injection of neutralizing FcRY antibodies in laying quail markedly reduced IgY uptake into egg yolks. The neutralization also showed that FcRY was engaged in prolongation of half-life of IgY in the blood; FcRY is therefore a multifunctional receptor that controls avian immunity. The pattern of the transport of the IgY mutants from the maternal blood to the egg yolk was found to be identical to that from the fertilized egg yolk to the newly-hatched chick blood circulation, via the yolk sac membrane. FcRY is therefore a critical IgY receptor that regulates the IgY uptake from the maternal blood circulation into the yolk of avian species, further indicating that the two steps of maternal-newly-hatched IgY transfer are controlled by a single receptor.


Assuntos
Galinhas , Células Endoteliais , Imunoglobulinas , Animais , Feminino , Humanos , Recém-Nascido , Células Endoteliais/metabolismo , Receptores Fc , Anticorpos/metabolismo
2.
Nanomaterials (Basel) ; 13(22)2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-37999301

RESUMO

Although the sound absorption coefficients of conventional and nanofiber nonwoven fabrics (NF-NWFs) have been the subject of many previous studies, few studies have considered the estimation of transmission loss. Reported herein is an experimental and theoretical study into estimating the transmission loss of NF-NWFs using four estimation models, i.e., the Rayleigh, Miki, and Komatsu models, and the simplified limp frame model (SLFM), with the model results compared against the experimental data. The transmission loss of the NF-NWF was determined from the propagation constant, and characteristic impedance was calculated using the estimation model and the transfer matrix method. The validity of each estimation method was examined by comparing its estimated values with the experimental values measured using a four-microphone impedance measurement tube. The proposed SLFM is more suitable for estimating the transmission loss of NF-NWFs than the conventional Rayleigh, Miki, and Komatsu models.

3.
Diabetes ; 72(11): 1609-1620, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37625131

RESUMO

The Cre-loxP system provides valuable resources to analyze the importance of tissue-specific gene knockout (KO), including pancreatic ß-cells associated with the pathogenesis of diabetes. However, it is expensive and time consuming to generate transgenic mice harboring floxed genes of interest and cross them with cell-specific Cre expression mice. We establish a ßCas9 system with mice expressing Cas9 in pancreatic ß-cells and adeno-associated virus 8 (AAV8)-mediated guide RNA (gRNA) delivery based on CRISPR-Cas9 technology to overcome those shortcomings. Interbreeding CAG-loxP-STOP-loxP (LSL)-Cas9 with Ins1-Cre mice generates normal glucose-tolerant ßCas9 mice expressing Cas9 with fluorescent reporter EGFP specifically in ß-cells. We also show significant ß-cell-specific gene KO efficiency with AAV8-mediated delivery of gRNA for EGFP reporter by intraperitoneal injection in the mice. As a proof of concept, we administered AAV8 to ßCas9 mice for expressing gRNA for Pdx1, a culprit gene of maturity-onset diabetes of the young 4. As reported previously, we demonstrate that those mice show glucose intolerance with transdifferentiation of Pdx1 KO ß-cells into glucagon-expressing cells. We successfully generated a convenient ß-cell-specific gene KO system with ßCas9 mice and AAV8-mediated gRNA delivery.

4.
Eur J Radiol ; 147: 110103, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35051691

RESUMO

BACKGROUND: Diffuse midline glioma (DMG), H3 K27M-mutant including diffuse intrinsic pontine glioma (DIPG) is a disease with dismal prognosis. We focused on diffusion-weighted imaging (DWI) and gadolinium enhanced T1WI (Gd), especially high intensity on DWI at non-enhanced lesion, i.e. DWI-Gd mismatch sign, to establish as an imaging biomarker of DMG patients. MATERIALS AND METHODS: Our institutional review board approved this retrospective study. Twenty-one patients diagnosed as DMG including DIPG at our institution between 2007 and 2020 were enrolled in this study. All patients underwent local radiotherapy of 54 Gy/30 fractions. We studied the relationship between imaging features including DWI-Gd mismatch sign and prognosis. RESULTS: DWI-Gd mismatch sign was found in 9 out of 21 DMG patients. Among different imaging characteristics, existence of high intensity on DWI (P = 0.0014), gadolinium enhancement (P = 0.00071) were the significant poor prognostic markers in DMG, which were consistent with the previous reports about DIPG. In our results, positive DWI-Gd mismatch sign was statistically strongest poor prognostic imaging biomarker, and patients with positive DWI-Gd mismatch sign had shorter OS compared to those with negative mismatch sign (9.9 months vs 18.6 months, P = 0.00062). DWI/Gd mismatch sign and intratumoral bleeding were more common in DMG at thalamus compared to DMG at pons/DIPG (P = 0.046 and P = 0.0017, respectively). CONCLUSIONS: DWI-Gd mismatch sign may be an imaging biomarker for poor prognosis in DMG. (E-1601).


Assuntos
Gadolínio , Glioma , Meios de Contraste , Glioma/diagnóstico por imagem , Humanos , Mutação , Estudos Retrospectivos
5.
Sci Rep ; 10(1): 12334, 2020 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-32703978

RESUMO

The molecular shield effect was studied for intrinsically disordered proteins (IDPs) that do not adopt compact and stable protein folds. IDPs are found among many stress-responsive gene products and cryoprotective- and drought-protective proteins. We recently reported that some fragments of human genome-derived IDPs are cryoprotective for cellular enzymes, despite a lack of relevant amino acid sequence motifs. This sequence-independent IDP function may reflect their molecular shield effect. This study examined the inhibitory activity of IDPs against fibril formation in an amyloid beta peptide (Aß(1-42)) model system. Four of five human genome-derived IDPs (size range 20 to 44 amino acids) showed concentration-dependent inhibition of amyloid formation (IC50 range between 60 and 130 µM against 20 µM Aß(1-42)). The IC50 value was two orders of magnitude lower than that of polyethylene-glycol and dextran, used as neutral hydrophilic polymer controls. Nuclear magnetic resonance with 15 N-labeled Aß(1-42) revealed no relevant molecular interactions between Aß(1-42) and IDPs. The inhibitory activities were abolished by adding external amyloid-formation seeds. Therefore, IDPs seemed to act only at the amyloid nucleation phase but not at the elongation phase. These results suggest that IDPs (0.1 mM or less) have a molecular shield effect that prevents aggregation of susceptible molecules.


Assuntos
Peptídeos beta-Amiloides/química , Proteínas Intrinsicamente Desordenadas/química , Fragmentos de Peptídeos/química , Peptídeos beta-Amiloides/genética , Humanos , Proteínas Intrinsicamente Desordenadas/genética , Fragmentos de Peptídeos/genética
6.
J Am Chem Soc ; 142(33): 14039-14044, 2020 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-32709201

RESUMO

A new mode of bond activation involving M→Z interactions is disclosed. Coordination to transition metals as σ-acceptor ligands was found to enable the activation of fluorosilanes, opening the way to the first transition-metal-catalyzed Si-F bond activation. Using phosphines as directing groups, sila-Negishi couplings were developed by combining Pd and Ni complexes with external Lewis acids such as MgBr2. Several key catalytic intermediates have been authenticated spectroscopically and crystallographically. Combined with DFT calculations, all data support cooperative activation of the fluorosilane via Pd/Ni→Si-F→Lewis acid interaction with conversion of the Z-type fluorosilane ligand into an X-type silyl moiety.

7.
Am J Phys Anthropol ; 167(2): 327-336, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30222182

RESUMO

OBJECTIVES: In group-living primates, it has been reported that the alpha male exhibits high concentrations of cortisol and testosterone in the context of mating competition. We investigated how the presence of females affected salivary cortisol and testosterone levels in males from a small captive group of chimpanzees (Pan troglodytes). Specifically, we assessed whether the presence of females resulted in a rapid increase in salivary cortisol and testosterone levels in the alpha male. MATERIALS AND METHODS: We compared the social behavior and salivary hormone concentrations of four males before and after the presentation of receptive females. Three times a day, we collected saliva samples, a useful matrix for investigating short-term hormonal changes, and measured cortisol and testosterone concentration by liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS: The frequency of inter-male aggression increased in the presence of females, indicating intense competition among males. Salivary cortisol levels increased in all males in the presence of females; however, the increase was significantly more pronounced in the alpha male. We found a complex three-way interaction among the presence of females, sampling timings, and male dominance rank in the analysis of salivary testosterone. Contrary to our prediction, a post hoc analysis revealed that salivary testosterone levels decreased after female introduction and that the alpha male did not show a higher level of salivary testosterone. CONCLUSIONS: Our study provides experimental evidence suggesting that the presence of females plays a significant role in the rank-related variation in the cortisol levels in male chimpanzees. Furthermore, our findings demonstrate the usefulness of salivary hormones for detecting short-term physiological changes in studies of socioendocrinology.


Assuntos
Agressão/fisiologia , Hidrocortisona/análise , Pan troglodytes/fisiologia , Comportamento Sexual Animal/fisiologia , Animais , Feminino , Hierarquia Social , Masculino , Saliva/química , Testosterona/análise
8.
Biochem Biophys Res Commun ; 486(4): 1077-1082, 2017 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-28377223

RESUMO

DYKDDDDK peptide (FLAG) is a useful tool for investigating the function and localization of proteins whose antibodies (Abs) are not available. We recently established a high-affinity monoclonal antibody (mAb) for FLAG (clone 2H8). The 2H8 Ab is highly sensitive for detecting FLAG-tagged proteins by flowcytometry and immunoprecipitation, but it can yield nonspecific signals in immunohistochemistry of mouse tissues because it is of mouse origin. In this study, we reduced nonspecific signals by generating a chimeric 2H8 Ab with Fc fragments derived from human immunoglobulin. We fused a 5' terminal cDNA fragments for the Fab region of 2H8 mAb with 3' terminal cDNA fragments for Fc region of human IgG1. We transfected both chimeric plasmids and purified the resulting human-mouse chimeric 2H8. The chimeric 2H8 Ab successfully detected FLAG-tagged proteins in flowcytometry with anti-human IgG secondary Ab with comparable sensitivity to 2H8 mAb. Importantly, chimeric 2H8 detected specific FLAG peptide signals without nonspecific signals in immunohistochemical analysis with mouse tissues. This human-mouse chimeric high-affinity anti-FLAG Ab will prove useful for future immunohistochemical analysis of mouse tissues.


Assuntos
Anticorpos Monoclonais/imunologia , Imunoprecipitação/métodos , Oligopeptídeos/imunologia , Engenharia de Proteínas/métodos , Animais , Anticorpos Monoclonais/genética , Humanos , Camundongos
9.
Front Psychol ; 6: 581, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26042056

RESUMO

Whether visual working memory (WM) consists of a common storage resource or of multiple subsystems has been a controversial issue. Logie (1995) suggested that it can be divided into visual (for color, shape, objects, etc.) and spatial WM (for location). However, a recent study reported evidence against this hypothesis. Using a dual task paradigm, Wood (2011) showed interference between shape and spatial WM capacities, suggesting that they share a common resource limitation. We re-examined this finding controlling possible confounding factors, including the way to present spatial location cues, task order, and type of WM load to be manipulated. The same pattern of results was successfully reproduced, but only in a highly powered experiment (N = 90), and therefore the size of interference was estimated to be quite small (d = 0.24). Thus, these data offer a way to reconcile seemingly contradicting previous findings. On the one hand, some part of the storage system is genuinely shared by shape and spatial WM systems, confirming the report of Wood (2011). On the other hand, the amount of the overlap is only minimal, and therefore the two systems should be regarded as mostly independent from each other, supporting the classical visuo-spatial separation hypothesis.

10.
Psychophysiology ; 50(9): 864-71, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23834356

RESUMO

Motivation is well known to enhance working memory (WM) capacity, but the mechanism underlying this effect remains unclear. The WM process can be divided into encoding, maintenance, and retrieval, and in a change detection visual WM paradigm, the encoding and retrieval processes can be subdivided into perceptual and central processing. To clarify which of these segments are most influenced by motivation, we measured ERPs in a change detection task with differential monetary rewards. The results showed that the enhancement of WM capacity under high motivation was accompanied by modulations of late central components but not those reflecting attentional control on perceptual inputs across all stages of WM. We conclude that the "state-dependent" shift of motivation impacted the central, rather than the perceptual functions in order to achieve better behavioral performances.


Assuntos
Albuminas 2S de Plantas/fisiologia , Antígenos de Plantas/fisiologia , Atenção/fisiologia , Potenciais Evocados/fisiologia , Memória de Curto Prazo/fisiologia , Motivação/fisiologia , Desempenho Psicomotor/fisiologia , Percepção Visual/fisiologia , Adulto , Eletroencefalografia , Humanos , Adulto Jovem
11.
Psychophysiology ; 50(1): 60-9, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23153284

RESUMO

Previous studies utilizing the N2pc, an ERP correlate of attentional focusing, demonstrated that fearful faces grab attention regardless of their relevance to the current task. We tested whether this apparent automaticity was susceptible to high concurrent task demand, which is known to suppress other cortical and subcortical emotional evaluations. Our data revealed that the affective attentional capture occurred even under high task load, by which the late cortical affective activity (the LPP modulation) was entirely suppressed. We also confirmed that this effect did not occur to inverted faces and therefore required a holistic perception of facial expression. These results show that, given an intact processing of facial expression, attention is attracted by fearful faces in a relatively automatic fashion as compared to other cortical affective processes.


Assuntos
Atenção/fisiologia , Córtex Cerebral/fisiologia , Potenciais Evocados/fisiologia , Expressão Facial , Medo/fisiologia , Adulto , Mapeamento Encefálico , Eletroencefalografia , Feminino , Humanos , Masculino , Tempo de Reação/fisiologia
12.
Psychophysiology ; 49(3): 427-40, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22091961

RESUMO

While response delays after task switching have been widely used as an index to investigate the limits of cognitive flexibility, little is known about their counterpart in error rates. It has been hypothesized that at least some postswitching errors are not caused by simple response errors but by task confusion, which refers to the establishment and execution of an incorrect task set. The aim of the current study is to provide evidence for this hypothesis. Using a multitrial paradigm, we firstly dissociated task confusion from simple cue encoding failure, and then measured the error-related negativity (ERN) and the following error positivity (Pe) as indices of the brain's error processing. We predicted that task confusion, if it exists, would cause ambiguity to the criteria of correct response, and therefore attenuate error processing. Results confirmed our prediction, suggesting that task confusion actually occurs after switching.


Assuntos
Encéfalo/fisiologia , Sinais (Psicologia) , Potenciais Evocados/fisiologia , Desempenho Psicomotor/fisiologia , Adulto , Eletroencefalografia , Feminino , Humanos , Masculino , Análise e Desempenho de Tarefas
13.
J Gen Virol ; 91(Pt 8): 2049-2053, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20375224

RESUMO

Nine male chimpanzees originally reared in solitary cages were set up to form a group. Plasma viral load of the lymphocryptovirus (LCV) of chimpanzee [Epstein-Barr virus chimpanzee (EBVcmp)] was measured by real-time PCR. In the group formation (Form) period, the first-ranking male showed an imminent increase in plasma EBVcmp load compared with 1 week before (pre-Form) and 3 months after (post-Form) group formation. Other upper-ranking males such as the second-, third- and fourth-male also showed the highest level of viral load in the Form period. The kinetics of EBVcmp load in the Form period were statistically different from other periods (against pre-Form, t=-4.878, P<0.001; against post-Form, t=6.434, P<0.001). The effect of the male dominance rank did not differ between the pre-Form and post-Form periods (t=-1.557, P=0.12). Reactivation of LCV (EBV) as an immunological stress marker for humans might also be applied to chimpanzees.


Assuntos
Doenças dos Símios Antropoides/virologia , Infecções por Herpesviridae/veterinária , Lymphocryptovirus/isolamento & purificação , Ativação Viral , Animais , Infecções por Herpesviridae/virologia , Lymphocryptovirus/fisiologia , Masculino , Pan troglodytes , Plasma/virologia , Reação em Cadeia da Polimerase , Carga Viral
14.
Dig Endosc ; 21(1): 34-6, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19691799

RESUMO

A 73-year-old man with short segmental Barrett's esophagus underwent esophagoscopy, and a slightly depressed, discolored lesion was found on the anterior wall of the lower esophagus. Under a provisional diagnosis of differentiated adenocarcinoma without local lymph node metastasis, endoscopic submucosal dissection (ESD) was carried out. En bloc resection with tumor-free lateral/basal margins was accomplished without complication. The resected area was 12 x 15 mm in size, whereas the neoplastic lesion was 4 x 4 mm. Histopathological examination confirmed intramucosal well-differentiated tubular adenocarcinoma without angiolymphatic invasion adjacent to the muscularis mucosae. Repeated esophagoscopy 6 months after ESD showed neither locally recurrent nor metachronous lesions. Considering that Barrett's esophagus is a precancerous condition, one may recommend eradication of both the neoplastic and non-neoplastic lesion with using ESD.


Assuntos
Adenocarcinoma/cirurgia , Esôfago de Barrett/complicações , Neoplasias Esofágicas/cirurgia , Adenocarcinoma/etiologia , Idoso , Neoplasias Esofágicas/etiologia , Esofagoscopia , Humanos , Masculino , Mucosa/cirurgia
15.
Am J Primatol ; 71(8): 696-706, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19452511

RESUMO

Owing to its high temporal sensitivity, saliva has distinct advantages for measuring steroids, compared with other noninvasive samples such as urine and feces. Here, we report the validity of assaying salivary cortisol (C) and testosterone (T) using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in captive male chimpanzees, Pan troglodytes. For both the C and T concentrations, we found positive relationships between saliva and plasma. The concentrations of C and T in saliva showed clear patterns of diurnal fluctuation, whereas those in urine and feces did not. These results suggest that the salivary steroid concentrations can be regarded as good indicators of circulating steroid levels. We also developed and validated an efficient method for collecting saliva samples from cotton rope. Although rope includes inherent steroid-like compounds and may affect the accuracy of steroid measurements, our rope-washing procedures effectively removed intrinsic steroidal materials. There was a significant association between the C and T concentrations measured from saliva collected from rope licked by the chimpanzees and those measured from saliva collected directly from the mouth. Salivary T values estimated by LC/MS-MS were similar to those measured by radioimmunoassay. The results indicate the usefulness of saliva as a noninvasive steroid measure and that steroids in the saliva of chimpanzees can be accurately measured by LC-MS/MS.


Assuntos
Cromatografia Líquida , Hidrocortisona/análise , Pan troglodytes/metabolismo , Saliva/química , Espectrometria de Massas em Tandem , Testosterona/análise , Animais , Ritmo Circadiano , Fezes/química , Hidrocortisona/sangue , Hidrocortisona/urina , Masculino , Radioimunoensaio , Sensibilidade e Especificidade , Manejo de Espécimes/métodos , Manejo de Espécimes/veterinária , Testosterona/sangue , Testosterona/urina
16.
Neuro Endocrinol Lett ; 29(4): 451-3, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18766143

RESUMO

OBJECTIVES: This study was aimed to examine the relationships between salivary alpha-amylase (sAA, a non-invasive biological marker of adrenergic activities) levels and hyperbolic discounting for primary reward under simulated life-threatening condition, which is of interest in psychoneuroendocrinology and neuroeconomics of visceral influences on behavior. METHODS: We assessed degrees to which delayed primary reward (i.e., water) was discounted (hyperbolic discount rates) in 31 healthy male students. Participants' sAA were also assessed. RESULTS: We observed a positive correlation between sAA and hyperbolic discounting for primary reward. CONCLUSIONS: The result indicates that threat-induced visceral urge acutely prompts impulsivity in temporal discounting.


Assuntos
Recompensa , Saliva/enzimologia , alfa-Amilases/metabolismo , Humanos , Comportamento Impulsivo , Masculino , Neuroendocrinologia , Estatística como Assunto , Inquéritos e Questionários
17.
Neuro Endocrinol Lett ; 28(5): 662-5, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17984929

RESUMO

OBJECTIVE: Little is known regarding the relationship between social evaluation-induced neuroendocrine responses and generosity in game-theoretic situations. Previous studies demonstrated that reputation formation plays a pivotal role in prosocial behavior. This study aimed to examine the relationships between a social evaluation-induced salivary alpha-amylase (sAA) response and generosity in the dictator game. The relationship is potentially important in neuroeconomics of altruism and game theory. METHODS: We assessed sAA and allocated money in the dictator game in male students with and without social evaluation. RESULTS Social evaluation-responders allocated significantly more money than controls; while there was no significant correlation between social evaluation-induced sAA elevation and the allocated money. CONCLUSIONS: Social evaluation significantly increases generosity in the dictator game, and individual differences in trait characteristics such as altruism and reward sensitivity may be important determinants of generosity in the dictator game task.


Assuntos
Altruísmo , Amilases/metabolismo , Tomada de Decisões/fisiologia , Jogos Experimentais , Percepção Social , Adolescente , Adulto , Humanos , Masculino , Valores de Referência , Recompensa , Saliva/metabolismo , Autoimagem
18.
Behav Brain Funct ; 3: 52, 2007 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-17892596

RESUMO

BACKGROUND: Hyperbolic discounting of delayed and probabilistic outcomes has drawn attention in psychopharmacology and neuroeconomics. Sozou's evolutionary theory proposed that hyperbolic delay discounting may be totally attributable to aversion to a decrease in subjective probability of obtaining delayed rewards (SP) which follows a hyperbolic decay function. However, to date, no empirical study examined the hypothesis, although this investigation is important for elucidating the roles of impatience, precaution, and uncertainty aversion in delay discounting processes. METHODS: In order to (i) determine the functional form of the relation between delay until receipt and SP, and (ii) examine whether delay discounting is attributable to a decrease in SP, we assessed the subjects' SP and their delay and probability discounting. We examined the fitness of hyperbolic and exponential functions to the assessed SP, and relations between the SP, and delay/probability discounting, and subjective-probability discounting for delayed rewards. RESULTS: The results demonstrated (a) SP decayed hyperbolically as delay increases, (b) a decay of SP was associated with delay discounting, and (c) subjective-probability discounting did not significantly correlate with delay discounting. CONCLUSION: Our results demonstrated (i) hyperbolic decay of SP is related to delay discounting, and (ii) delay discounting is, however, not attributable to precautious foresight in intertemporal choice. Further, a novel parameter of pure time preference is proposed.

19.
Neuro Endocrinol Lett ; 28(1): 17-20, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17277731

RESUMO

OBJECTIVE: Little is known regarding the role of the sympathetic-adrenal-medullary (SAM) system in self-control and impulsivity in intertemporal choice (delay discounting), although the roles of dopaminergic and serotonergic systems have been extensively examined. This study was aimed to examine the relationships between salivary alpha-amylase (sAA, a non-invasive biological marker of adrenergic/SAM activities) levels and hyperbolic discounting, which is of interest in psychoneuroendocrinology and neuroeconomics. METHODS: We assessed degrees to which delayed monetary gains were discounted (hyperbolic discount rates) in healthy male students. Participants' sAA were also assessed. RESULTS: We observed negative relationships between sAA and hyperbolic discounting of small, medium, and large monetary gains. CONCLUSIONS: The results indicate that subjects with low sAA are impulsive in intertemporal choice. Implications for the roles of adrenergic and SAM systems in self-control in intertemporal choice are discussed.


Assuntos
Medula Suprarrenal/fisiologia , Comportamento Impulsivo/metabolismo , Comportamento Impulsivo/psicologia , alfa-Amilases/metabolismo , Adolescente , Adulto , Comportamento de Escolha/fisiologia , Humanos , Comportamento Impulsivo/fisiopatologia , Masculino , Saliva/química , Sistema Nervoso Simpático/fisiologia , Testosterona/metabolismo , alfa-Amilases/análise
20.
Neuro Endocrinol Lett ; 26(4): 351-4, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16136010

RESUMO

OBJECTIVES: Traditionally, it has been hypothesized that highly anxious/emotionally reactive subjects may have exaggerated social stress response. We examined the relationship between self-reported anxiety, emotional reactivity, and social stress response. METHODS: We investigated the relationship between personality scales of trait-state anxiety, subjective autonomic reactivity, and salivary cortisol levels before and after social stress exposure (Trier Social Stress Test) in 20 men. RESULTS: Significant positive correlations between anxiety, subjective autonomic reactivity, and basal cortisol levels were observed, while neither anxiety nor subjective autonomic reactivity was correlated with social stress-induced cortisol elevation. CONCLUSIONS: The present results indicate (i) subjects with higher degrees of trait anxiety/subjective autonomic reactivity have higher basal cortisol levels, and (ii) in contrast to the traditional view, anxious personality is not strongly associated with exaggerated cortisol response to social stress.


Assuntos
Ansiedade/sangue , Hidrocortisona/sangue , Personalidade/fisiologia , Estresse Psicológico/sangue , Doença Aguda , Adulto , Humanos , Masculino , Comportamento Social
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