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1.
J Am Chem Soc ; 146(8): 5580-5596, 2024 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-38347659

RESUMEN

Under mild blue-light irradiation, α-acylated saturated heterocycles undergo a photomediated one-atom ring contraction that extrudes a heteroatom from the cyclic core. However, for nitrogenous heterocycles, this powerful skeletal edit has been limited to substrates bearing electron-withdrawing substituents on nitrogen. Moreover, the mechanism and wavelength-dependent efficiency of this transformation have remained unclear. In this work, we increased the electron richness of nitrogen in saturated azacycles to improve light absorption and strengthen critical intramolecular hydrogen bonding while enabling the direct installation of the photoreactive handle. As a result, a broadly expanded substrate scope, including underexplored electron-rich substrates and previously unsuccessful heterocycles, has now been achieved. The significantly improved yields and diastereoselectivities have facilitated reaction rate, kinetic isotope effect (KIE), and quenching studies, in addition to the determination of quantum yields. Guided by these studies, we propose a revised ET/PT mechanism for the ring contraction, which is additionally corroborated by computational characterization of the lowest-energy excited states of α-acylated substrates through time-dependent DFT. The efficiency of the ring contraction at wavelengths longer than those strongly absorbed by the substrates was investigated through wavelength-dependent rate measurements, which revealed a red shift of the photochemical action plot relative to substrate absorbance. The elucidated mechanistic and photophysical details effectively rationalize empirical observations, including additive effects, that were previously poorly understood. Our findings not only demonstrate enhanced synthetic utility of the photomediated ring contraction and shed light on mechanistic details but may also offer valuable guidance for understanding wavelength-dependent reactivity for related photochemical systems.

2.
BMC Psychiatry ; 24(1): 138, 2024 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-38373899

RESUMEN

BACKGROUND: Nonsuicidal self-injury (NSSI) combined with suicide ideation increases the risk of suicidal behaviors. Depression and posttraumatic stress disorder (PTSD) are comorbidities of NSSI compounding this relationship. The present study compared diagnostic subgroups of NSSI based on current depression and PTSD on psychological correlates (i.e., vulnerabilities and impairment) and suicidal presentations (i.e., suicidal cognitions and behaviors) in a psychiatric sample of adolescents. METHODS: Eighty-seven adolescents meeting DSM-5 criteria for NSSI and 104 age-range-matched nonclinical controls (NC) participated. Participants completed self-report measures on psychological vulnerabilities and impairment (e.g., emotion regulation difficulties, negative cognitions). Adolescents with NSSI also completed clinical interviews on psychiatric diagnoses and a recent self-injurious behavior (SIB). Scores on the psychological correlates of NSSI were compared between adolescents with NSSI and NC, and across three diagnostic subgroups of NSSI (A: NSSI+/depression-/PTSD-, n = 14; B: NSSI+/depression+/PTSD-, n = 57; C: NSSI+/depression+/PTSD+, n = 14). Differences between NSSI diagnostic subgroups were tested on the motives for SIB and accompanying suicidal presentations (e.g., desire, intent, motive, lethality). RESULTS: Common comorbidities of NSSI included depression, panic disorder, generalized anxiety disorder, and PTSD. The NSSI subgroup classification was significantly associated with panic disorder, which was controlled for in the subsequent group comparisons. Overall, adolescents who engage in NSSI with vs. without depression reported more psychological vulnerabilities and impairment and a greater degree of suicidal thoughts/desire in SIB (i.e., groups B, C >A), which remained significant after controlling for panic disorder. An increased odds of the suicidal motive for SIB was found in adolescents with all three conditions (i.e., group C: NSSI+/depression+/PTSD+) compared to those with NSSI but neither depression nor PTSD (i.e., group A: NSSI+/depression-/PTSD-); however, this was not significant after controlling for panic disorder. CONCLUSIONS: Psychological underpinnings of adolescent NSSI in clinical contexts may be largely associated with concurrent depression. Suicidal motives in adolescents who engage in NSSI in the presence of depression and PTSD may be confounded by the co-occurrence of panic disorder. This study warrants the importance of attending to the comorbid depression with NSSI in adolescents as it is related to an increase in suicidal desire accompanying SIB.


Asunto(s)
Conducta Autodestructiva , Trastornos por Estrés Postraumático , Humanos , Adolescente , Ideación Suicida , Trastornos por Estrés Postraumático/diagnóstico , Trastornos por Estrés Postraumático/epidemiología , Depresión/diagnóstico , Conducta Autodestructiva/diagnóstico , Conducta Autodestructiva/psicología , Trastornos de Ansiedad , Factores de Riesgo
3.
Health Commun ; : 1-16, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38299636

RESUMEN

The current study has three main purposes: to examine 1) the impact of theory-driven corrective messages using individual vs. collective frames on information-seeking intention 2) the mediating role of risk perceptions and 3) the moderating role of reflection and gender. Our findings from a randomized experimental study and Hayes' moderated, moderated mediation model show collective frames were associated with high-risk perceptions among women, which in turn led to higher information seeking intention. The second moderator reveals that people who scored higher on reflection were more willing to seek information. Our findings have critical implications for misinformation research by demonstrating the importance of theoretically driven messages in understanding misperceptions as well as people's information seeking behavior.

4.
Int J Mol Sci ; 25(6)2024 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-38542065

RESUMEN

Non-alcoholic fatty liver disease (NAFLD) has emerged as a significant liver ailment attributed to factors like obesity and diabetes. While ongoing research explores treatments for NAFLD, further investigation is imperative to address this escalating health concern. NAFLD manifests as hepatic steatosis, precipitating insulin resistance and metabolic syndrome. This study aims to validate the regenerative potential of chimeric fibroblast growth factor 21 (FGF21) and Hepatocyte Growth Factor Receptor (HGFR) in NAFLD-afflicted liver cells. AML12, a murine hepatocyte cell line, was utilized to gauge the regenerative effects of chimeric FGF21/HGFR expression. Polysaccharide accumulation was affirmed through Periodic acid-Schiff (PAS) staining, while LDL uptake was microscopically observed with labeled LDL. The expression of FGF21/HGFR and NAFLD markers was analyzed by mRNA analysis with RT-PCR, which showed a decreased expression in acetyl-CoA carboxylase 1 (ACC1) and sterol regulatory element binding protein (SREBP) cleavage-activating protein (SCAP) with increased expression of hepatocellular growth factor (HGF), hepatocellular nuclear factor 4 alpha (HNF4A), and albumin (ALB). These findings affirm the hepato-regenerative properties of chimeric FGF21/HGFR within AML12 cells, opening novel avenues for therapeutic exploration in NAFLD.


Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , Animales , Ratones , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/genética , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Proteínas Proto-Oncogénicas c-met/metabolismo , Hígado/metabolismo , Factores de Crecimiento de Fibroblastos/genética , Factores de Crecimiento de Fibroblastos/metabolismo
5.
BMC Cancer ; 23(1): 580, 2023 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-37353748

RESUMEN

BACKGROUND: Weight changes after gastrectomy affect not only quality of life but also prognosis and survival. However, it remains challenging to predict the weight changes of individual patients. Using clinicopathological variables, we built a user-friendly tool to predict weight change after curative gastrectomy for gastric cancer. METHODS: The clinical data of 984 patients who underwent curative gastrectomy between 2009 and 2013 were retrospectively reviewed and analyzed. Multivariate logistic regression was performed to identify variables predictive of postoperative weight change. A nomogram was developed and verified via bootstrap resampling. RESULTS: Age, sex, performance status, body mass index, extent of resection, pathological stage, and postoperative weight change significantly influenced postoperative weight recovery. Postoperative levels of hemoglobin, albumin, ferritin and total iron-binding capacity were significant covariates. The nomogram performed well (concordance index = 0.637); calibration curves indicated appropriate levels of agreement. We developed an online weight prediction calculator based on the nomogram ( http://gc-weightchange.com/en/front/ ). CONCLUSIONS: The novel, Web-calculator based on the predictive model allows surgeons to explore patient weight patterns quickly. The model identifies patients at high risk for weight loss after gastrectomy; such patients require multidisciplinary medical support.


Asunto(s)
Neoplasias Gástricas , Humanos , Estudios Retrospectivos , Neoplasias Gástricas/patología , Calidad de Vida , Pronóstico , Nomogramas , Gastrectomía/efectos adversos
6.
J Korean Med Sci ; 38(17): e132, 2023 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-37128876

RESUMEN

BACKGROUND: This study aimed to empirically derive and validate subtypes of nonsuicidal self-injury (NSSI) based on the forms of self-harm behavior. METHODS: Sixty young adults who exhibited repetitive NSSI completed a clinical interview and baseline measures, followed by a two-week ecological momentary assessment (EMA). A latent class analysis was administered to identify NSSI subtypes based on the forms of self-harm behavior. The subtypes were then compared to baseline clinical and EMA variables, including emotions and urges to self-harm. RESULTS: The best-fitting model supported two subtypes: 1) substance abuse and suicide attempt subtype and 2) cutting and scratching subtype. The substance abuse and suicide attempt subtype reported a higher rate of engaging in lifetime suicide plans and suicide attempts and a higher number of lifetime suicide attempts. They also showed significantly higher severity of self-harm behavior, borderline personality traits, anger, posttraumatic symptoms, and difficulties in emotion regulation when compared to the cutting and scratching subtype. However, there was no inter-subtype difference in self-esteem. In the EMA data, anger toward others, feeling of rejection, loneliness, and helplessness were significantly high in the substance abuse and suicide attempt subtype. The variability of anger toward others was also higher in this subtype compared to the cutting and scratching subtype. Finally, in the two-week research period, the substance abuse and suicide attempt group showed a higher rate of reported urges to self-harm with or without suicidal intent. CONCLUSION: Findings support the validity of the subtypes based on the forms of self-harm behavior, suggesting the clinical utility of addressing heterogeneity within individuals exhibiting self-harm for assessment and treatment.


Asunto(s)
Conducta Autodestructiva , Trastornos Relacionados con Sustancias , Adulto Joven , Humanos , Análisis de Clases Latentes , Evaluación Ecológica Momentánea , Intento de Suicidio/psicología , Ideación Suicida , Factores de Riesgo
7.
J Biomed Sci ; 29(1): 106, 2022 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-36536341

RESUMEN

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by progressive paralysis due to motor neuron degeneration. It has been proposed that epigenetic modification and transcriptional dysregulation may contribute to motor neuron death. In this study, we investigate the basis for therapeutic approaches to target lysine-specific histone demethylase 1 (LSD1) and elucidate the mechanistic role of LSD1-histone H3K4 signaling pathway in ALS pathogenesis. METHODS: In order to examine the role of spermidine (SD), we administered SD to an animal model of ALS (G93A) and performed neuropathological analysis, body weight, and survival evaluation. RESULTS: Herein, we found that LSD1 activity is increased while levels of H3K4me2, a substrate of LSD1, is decreased in cellular and animal models of ALS. SD administration modulated the LSD1 activity and restored H3K4me2 levels in ChAT-positive motor neurons in the lumbar spinal cord of ALS mice. SD prevented cellular damage by improving the number and size of motor neurons in ALS mice. SD administration also reduced GFAP-positive astrogliogenesis in the white and gray matter of the lumbar spinal cord, improving the neuropathology of ALS mice. Moreover, SD administration improved the rotarod performance and gait analysis of ALS mice. Finally, SD administration delayed disease onset and prolonged the lifespan of ALS (G93A) transgenic mice. CONCLUSION: Together, modulating epigenetic targets such as LSD1 by small compounds may be a useful therapeutic strategy for treating ALS.


Asunto(s)
Esclerosis Amiotrófica Lateral , Ratones , Animales , Esclerosis Amiotrófica Lateral/metabolismo , Espermidina/metabolismo , Espermidina/uso terapéutico , Histonas/metabolismo , Superóxido Dismutasa , Neuronas Motoras , Médula Espinal/metabolismo , Médula Espinal/patología , Ratones Transgénicos , Modelos Animales de Enfermedad
8.
Nicotine Tob Res ; 24(2): 280-284, 2022 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-34520552

RESUMEN

INTRODUCTION: Visual attention is a crucial mechanism in health messaging and campaign persuasiveness. Little is known about how visual attention may translate into cessation-related outcomes in tobacco public education campaigns. METHODS: Using the eye-tracking technology, this study investigated the relationships among visual attention, cognitive and affective message responses, and cessation-related outcomes (readiness to quit, intentions to quit, and intentions to seek cessation information). Four different posters from the Every Try Counts (ETC) campaign were used as message stimuli. A total of 80 adult current smokers participated. The associations between their behavioral eye gaze patterns and self-reported message responses and cessation-related outcomes were examined. RESULTS: Half of the sample (49.4%) were male, and 46.8% were White-with ages ranging from 18 to 36 years old (M = 21.22, SD = 2.86). Roughly 41% were daily smokers, and 78% had attempted quitting in the previous year. When exposed to campaign ads, only fixation on the FDA logo showed consistent positive relationships with cognitive and affective message responses. Mediation analyses revealed significant indirect effects of fixation on the FDA logo on quitting and information-seeking intentions mainly through positive affective message responses. CONCLUSIONS: Visual attention to the FDA logo played an important role in the effects of ETC campaign messages. IMPLICATIONS: This study contributes new evidence on the relationship of visual attention, message responses, and ETC campaign outcomes. The current findings suggest that highlighting FDA as a campaign sponsor in the visual display may enhance the effectiveness of FDA tobacco education messages.


Asunto(s)
Cese del Hábito de Fumar , Productos de Tabaco , Adolescente , Adulto , Tecnología de Seguimiento Ocular , Promoción de la Salud , Humanos , Masculino , Fumadores/psicología , Cese del Hábito de Fumar/psicología , Adulto Joven
9.
J Exerc Sci Fit ; 20(1): 27-31, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34976077

RESUMEN

BACKGROUND/OBJECTIVE: Physical inactivity is one of the major cardiovascular disease risk factors; however, not much is known regarding lifetime bone-specific physical activity and arterial stiffness. The aim of this cross-sectional study was to determine whether total bone-specific physical activity score (tBPAQ) was related to arterial stiffness and body composition in healthy young adults. METHODS: Healthy young women (n = 56, 20.3 ± 1.3 years) and men (n = 52, 21.0 ± 1.2 years) between 18 and 25 years were recruited for this study. The tBPAQ was used to obtain a comprehensive account of lifetime bone-loading physical activity. We measured the carotid to femoral pulse wave velocity (cfPWV) to evaluate arterial stiffness using the novel oscillometric device (SphygmoCor XCEL). Dual energy X-ray absorptiometry was used to measure bone free lean body mass (BFLBM, kg) and % total body fat. RESULTS: Partial correlations analyses showed a significant inverse relationship between tBPAQ and cfPWV (r = - 0.371, p = 0.007) in young women; however, this relationship was not found in young men (p > 0.05). There were significant negative correlations between tBPAQ and % total body fat in both young women (r = - 0.265, p = 0.048) and men (r = - 0.327, p = 0.018). No significant relationships were found between tBPAQ and BFLBM (p > 0.05). CONCLUSION: Our study provides preliminary evidence of sex-specificity of negative relationships of tBPAQ with i) cfPWV (women only) and ii) % total body fat (men and women). Whether bone-loading physical activity can lead to better cardiometabolic outcomes needs to be examined.

10.
Plant Mol Biol ; 106(4-5): 463-477, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34100185

RESUMEN

KEY MESSAGE: OsPUB41 plays a negative role in drought stress response through the mediation of OsUBC25 and interacts with OsCLC6, suggesting a putative substrate. The notable expansion of Plant U-Box E3 ligases (PUB), compared with those in mammals, implies that PUB proteins have evolved to perform plant-specific functions. OsPUB41, a potential ortholog of CMPG1, was recently reported to regulate the cell wall degrading enzyme (CWDE)-induced innate immune response in rice. Here, we characterized the OsPUB41 gene, which encodes a dual-localized cytosolic and nuclear U-box E3 ligase in rice. OsPUB41 expression was specifically induced by dehydration among various abiotic stresses and abscisic acid (ABA) treatments. Furthermore, we revealed that the core U-box motif of OsPUB41 possesses the E3 ligase activity that can be activated by OsUBC25 in rice. The Ubi:RNAi-OsPUB41 knock-down and ospub41 suppression mutant plants exhibited enhanced tolerance to drought stress compared with the wild-type rice plants in terms of transpirational water loss, long-term dehydration response, and chlorophyll content. Moreover, the knock-down or suppression of the OsPUB41 gene did not cause adverse effect on rice yield-related traits. Yeast two-hybrid and an in vitro pull-down analyses revealed that OsCLC6, a chloride channel, is a putative substrate of OsPUB41. Overall, these results suggest that OsPUB41 acts as a negative regulator of dehydration conditions and interacts with OsCLC6, implying that it is a substrate of OsPUB41.


Asunto(s)
Oryza/enzimología , Estrés Fisiológico , Ubiquitina-Proteína Ligasas/genética , Ácido Abscísico/farmacología , Núcleo Celular/metabolismo , Canales de Cloruro/metabolismo , Citosol/metabolismo , Sequías , Técnicas de Silenciamiento del Gen , Mutación , Oryza/efectos de los fármacos , Oryza/genética , Plantas Modificadas Genéticamente , Ubiquitina-Proteína Ligasas/metabolismo
11.
Genome Res ; 2018 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-29472270

RESUMEN

Here, we report that CRISPR guide RNAs (gRNAs) with a 5'-triphosphate group (5'-ppp gRNAs) produced via in vitro transcription trigger RNA-sensing innate immune responses in human and murine cells, leading to cytotoxicity. 5'-ppp gRNAs in the cytosol are recognized by DDX58, which in turn activates type I interferon responses, causing up to ∼80% cell death. We show that the triphosphate group can be removed by a phosphatase in vitro and that the resulting 5'-hydroxyl gRNAs in complex with Cas9 or Cpf1 avoid innate immune responses and can achieve targeted mutagenesis at a frequency of 95% in primary human CD4+ T cells. These results are in line with previous findings that chemically synthesized sgRNAs with a 5'-hydroxyl group are much more efficient than in vitro-transcribed (IVT) sgRNAs in human and other mammalian cells. The phosphatase treatment of IVT sgRNAs is a cost-effective method for making highly active sgRNAs, avoiding innate immune responses in human cells.

12.
Health Commun ; 36(13): 1687-1696, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-32633151

RESUMEN

This study uses an unobtrusive eye tracking approach to examine understudied psychological mechanisms - message attention and credibility - when people are exposed to misinformation and correction on social media. We contrast humor versus non-humor correction strategies that point out rhetorical flaws in misinformation regarding the HPV vaccine, which was selected for its relevance and impact on public health. We randomly assigned participants to one of two experimental conditions: humor correction versus non-humor correction. Our analyses revealed that the humor correction increased attention to the image portion of the correction tweet, and this attention indirectly lowered HPV misperceptions by reducing the credibility of the misinformation tweet. The study also found that the non-humor correction outperformed the humor correction in reducing misperceptions via its higher credibility ratings. Practical implications for correcting misinformation on social media are discussed.


Asunto(s)
Vacunas contra Papillomavirus , Medios de Comunicación Sociales , Comunicación , Tecnología de Seguimiento Ocular , Humanos , Salud Pública
13.
Int J Mol Sci ; 22(19)2021 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-34638944

RESUMEN

Natural polysaccharides have shown promising effects on the regulation of immunity in animals. In this study, we examined the immune stimulatory effect of intranasally administered Codium fragile polysaccharides (CFPs) in mice. Intranasal administration of CFPs in C57BL/6 mice induced the upregulation of surface activation marker expression in macrophages and dendritic cells (DCs) in the mediastinal lymph node (mLN) and the production of interleukin-6 (IL-6), IL-12p70, and tumor necrosis factor-α in bronchoalveolar lavage fluid. Moreover, the number of conventional DCs (cDCs) was increased in the mLNs by the upregulation of C-C motif chemokine receptor 7 expression, and subsets of cDCs were also activated following the intranasal administration of CFP. In addition, the intranasal administration of CFPs promoted the activation of natural killer (NK) and T cells in the mLNs, which produce pro-inflammatory cytokines and cytotoxic mediators. Finally, daily administration of CFPs inhibited the infiltration of Lewis lung carcinoma cells into the lungs, and the preventive effect of CFPs on tumor growth required NK and CD8 T cells. Furthermore, CFPs combined with anti-programmed cell death-ligand 1 (PD-L1) antibody (Ab) improved the therapeutic effect of anti-PD-L1 Ab against lung cancer. Therefore, these data demonstrated that the intranasal administration of CFP induced mucosal immunity against lung cancer.


Asunto(s)
Adyuvantes Inmunológicos/administración & dosificación , Antineoplásicos/administración & dosificación , Carcinoma Pulmonar de Lewis/inmunología , Carcinoma Pulmonar de Lewis/terapia , Chlorophyta/química , Inmunidad Mucosa , Inmunoterapia/métodos , Neoplasias Pulmonares/inmunología , Neoplasias Pulmonares/terapia , Fitoterapia/métodos , Extractos Vegetales/administración & dosificación , Polisacáridos/administración & dosificación , Administración Intranasal/métodos , Animales , Linfocitos T CD8-positivos/inmunología , Carcinoma Pulmonar de Lewis/patología , Línea Celular Tumoral , Células Dendríticas/inmunología , Modelos Animales de Enfermedad , Femenino , Células Asesinas Naturales/inmunología , Neoplasias Pulmonares/patología , Activación de Linfocitos/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL
14.
Psychooncology ; 29(10): 1704-1712, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32779223

RESUMEN

OBJECTIVE: This investigation explores how using different e-health interventions facilitates positive psychosocial changes and how these changes reduce cancer concerns and improve quality of life in breast cancer patients over time. METHODS: A total of 326 breast cancer patients were randomly assigned to one of three e-health interventions: (a) Internet only, (b) the Comprehensive Health Enhancement Support System information and support services (CHESS-IS), or (c) CHESS with mentor. Proximal health outcomes such as information overload, emotional functioning, and social support were measured alongside distal outcomes like cancer concerns and quality of life. Participants completed surveys at four time points: pretest as a baseline, 6 weeks, 3 months, and 6 months. RESULTS: Both interventions were effective in improving patient health beyond Internet only but they differed in type of change mechanism and clinical benefit. The CHESS-IS enhanced proximal outcomes at 3 months through improved information competence. The CHESS with mentor intervention reduced breast cancer concerns at 6 months, mediated mainly by emotional-social competence and emotional functioning. CONCLUSIONS: Using e-health interventions like CHESS can help patients improve cancer information management skills and emotional functioning, contributing to better short-term health outcomes. Adding a human mentor can enhance the benefits of CHESS use, extending the experience among breast cancer patients. Theoretical, practical, and clinical implications of the study results are discussed.


Asunto(s)
Neoplasias de la Mama/psicología , Atención Integral de Salud/métodos , Internet , Calidad de Vida/psicología , Telemedicina/métodos , Adulto , Femenino , Humanos , Servicios de Información , Persona de Mediana Edad , Evaluación de Resultado en la Atención de Salud , Habilidades Sociales , Apoyo Social , Encuestas y Cuestionarios
15.
J Phys Chem A ; 124(28): 5856-5870, 2020 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-32497433

RESUMEN

The inherent conformational preferences of the neutral ß-peptide foldamer series, Ac-(ACHC)n-NHBn, n = 2-4, are studied in the gas phase using conformation-specific IR-UV double resonance methods. The cyclically constrained chiral ß-amino acid cis-2-aminocyclohexane carboxylic acid (ACHC) is designed to bring both right- and left-handed helices into close energetic proximity. Comparison of the infrared spectra in the NH stretch and amide I/II regions with the predictions of DFT calculations lead to the unambiguous assignment of four out of the six observed conformations of the molecules in this series, while corroborating computational and spectral evidence, affords tentative assignments of the remaining two conformers for which IR data were not recorded. The observed structures fall into one of two conformational families: a right-handed 12/10-mixed helix or its "cap-disrupted" left-handed helical analogue, which coexist with significant populations. Site-specific and stereospecific methylation on the cyclohexane backbone at the dipeptide (n = 2) level is also tested as a means to sterically lock in a predetermined cyclohexane chair conformation. These substitutions are proven to be a means of selectively driving formation of one helical screw sense or the other. Calculated relative energies and free energies of all possible structures for the molecules provide strong supporting evidence that the rigid nature of the ACHC residue confers unusual stability to the 12/10-mixed helix conformation, regardless of local environment, temperature, or C-terminal capping unit. The simultaneous presence of both handed helices offers unique opportunities for future studies of their interconversion.


Asunto(s)
Aminoácidos Cíclicos/química , Oligopéptidos/química , Ácidos Ciclohexanocarboxílicos/química , Ciclohexilaminas/química , Teoría Funcional de la Densidad , Enlace de Hidrógeno , Metilación , Modelos Químicos , Conformación Proteica en Hélice alfa , Termodinámica
16.
BMC Public Health ; 20(1): 709, 2020 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-32423398

RESUMEN

BACKGROUND: Accumulated evidence suggests that individuals with social anxiety disorder (SAD) are at particular risk of developing alcohol use disorder (AUD). Yet, little is known about the mechanisms under this high comorbidity. This study aimed to elucidate the process of the development of alcohol related problems among individuals with elevated social anxiety. We investigated the moderation effect of difficulties in emotion regulation on the relationship between symptoms of social anxiety, coping and conformity motives and alcohol related problems. METHODS: In a sample of university students (N = 647) in South Korea, we examined whether cognitive (fear of negative evaluation), behavioral (social avoidance), and physiological symptoms (concerns over physiological symptoms) of social anxiety affect alcohol related problems with the mediation of coping and conformity motives. Furthermore, difficulties in emotion regulation were hypothesized to moderate each mediational path. RESULTS: Results showed that the fear of negative evaluation and concerns over physiological symptoms were associated with alcohol related problems with the mediation of conformity and coping motives, respectively. As hypothesized, each path was moderated by difficulties in emotion regulation. CONCLUSIONS: Findings suggest that coping and conformity motives to cope with cognitive and physiological symptoms of social anxiety were related to alcohol related problems. In addition, individuals with high levels of difficulties in emotion regulation were prone to exhibit more alcohol related problems.


Asunto(s)
Consumo de Bebidas Alcohólicas/psicología , Ansiedad/psicología , Regulación Emocional , Estudiantes/psicología , Adaptación Psicológica , Alcoholismo/psicología , Miedo , Femenino , Humanos , Masculino , Motivación , Negociación , República de Corea , Conducta Social , Universidades , Adulto Joven
17.
Genome Res ; 26(3): 406-15, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26786045

RESUMEN

We present multiplex Digenome-seq to profile genome-wide specificities of up to 11 CRISPR-Cas9 nucleases simultaneously, saving time and reducing cost. Cell-free human genomic DNA was digested using multiple sgRNAs combined with the Cas9 protein and then subjected to whole-genome sequencing. In vitro cleavage patterns, characteristic of on- and off-target sites, were computationally identified across the genome using a new DNA cleavage scoring system. We found that many false-positive, bulge-type off-target sites were cleaved by sgRNAs transcribed from an oligonucleotide duplex but not by those transcribed from a plasmid template. Multiplex Digenome-seq captured many bona fide off-target sites, missed by other genome-wide methods, at which indels were induced at frequencies <0.1%. After analyzing 964 sites cleaved in vitro by these sgRNAs and measuring indel frequencies at hundreds of off-target sites in cells, we propose a guideline for the choice of target sites for minimizing CRISPR-Cas9 off-target effects in the human genome.


Asunto(s)
Sistemas CRISPR-Cas , Marcación de Gen , Genoma Humano , Genómica , Sitios de Unión , Genómica/métodos , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Mutación INDEL , Tasa de Mutación , Motivos de Nucleótidos , Posición Específica de Matrices de Puntuación , Unión Proteica , Reproducibilidad de los Resultados
18.
Chembiochem ; 20(8): 1078-1087, 2019 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-30609255

RESUMEN

Protein aggregation involves the assembly of partially misfolded proteins into oligomeric and higher-order structures that have been associated with several neurodegenerative diseases. However, numerous questions relating to protein aggregation remain unanswered due to the lack of available tools for visualization of these species in living cells. We recently developed a fluorogenic method named aggregation tag (AggTag), and presented the AggTag probe P1, based on a Halo-tag ligand, to report on the aggregation of a protein of interest (POI) in live cells. However, the Halo-tag-based AggTag method only detects the aggregation of one specific POI at a time. In this study, we have expanded the AggTag method by using SNAP-tag technology to enable fluorogenic and biorthogonal detection of the aggregation of two different POIs simultaneously in live cells. A new AggTag probe-P2, based on a SNAP-tag ligand bearing a green solvatochromic fluorophore-was synthesized for this purpose. Using confocal imaging and chemical crosslinking experiments, we confirmed that P2 can also report both on soluble oligomers and on insoluble aggregates of a POI fused with SNAP-tag in live cells. Ultimately, we showed that the orthogonal fluorescence of P1 and P2 allows for simultaneous visualization of two different pathogenic protein aggregates in the same cell.


Asunto(s)
Colorantes Fluorescentes/química , Proteínas/química , Fluorescencia , Células HEK293 , Humanos , Ligandos
19.
Health Commun ; 34(2): 162-171, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-29135321

RESUMEN

This study examined the interplay of depression and different types of e-health interventions on breast cancer patients' perceived healthcare competence, emotional processing, and social well-being over time. The three e-health interventions--Internet Only as a control condition, CHESS (Comprehensive Health Enhancement Support System) Only, and CHESS with a Human Mentor, a cancer information specialist--provided varying degrees of interactivity and presence. A total of 328 women with breast cancer participated in one of the three interventions for a 6-month period. Women were further split into two groups based on reported levels of depression. For perceived healthcare competence and social well-being, results revealed significant interaction effects for intervention type by depression over time, such that breast cancer patients with higher levels of depression benefited most from the CHESS with Mentor intervention over the 6-month study period. For emotional processing, depressed cancer patients benefited more from the CHESS with Mentor than the other two interventions, regardless of time. These findings have (a) theoretical implications on how mental health factors can intersect with interactivity and presence to influence psychosocial outcomes, (b) conceptual implications for the role of human interaction within e-health systems, and (c) practical implications for the development of e-health interventions for cancer patients with depression.


Asunto(s)
Neoplasias de la Mama/terapia , Depresión/psicología , Atención al Paciente , Apoyo Social , Telemedicina , Neoplasias de la Mama/psicología , Femenino , Humanos , Persona de Mediana Edad , Calidad de Vida
20.
J Immunol ; 196(10): 4263-73, 2016 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-27183642

RESUMEN

Class I HLA molecules mark infected cells for immune targeting by presenting pathogen-encoded peptides on the cell surface. Characterization of viral peptides unique to infected cells is important for understanding CD8(+) T cell responses and for the development of T cell-based immunotherapies. Having previously reported a series of West Nile virus (WNV) epitopes that are naturally presented by HLA-A*02:01, in this study we generated TCR mimic (TCRm) mAbs to three of these peptide/HLA complexes-the immunodominant SVG9 (E protein), the subdominant SLF9 (NS4B protein), and the immunorecessive YTM9 (NS3 protein)-and used these TCRm mAbs to stain WNV-infected cell lines and primary APCs. TCRm staining of WNV-infected cells demonstrated that the immunorecessive YTM9 appeared several hours earlier and at 5- to 10-fold greater density than the more immunogenic SLF9 and SVG9 ligands, respectively. Moreover, staining following inhibition of the TAP demonstrated that all three viral ligands were presented in a TAP-dependent manner despite originating from different cellular compartments. To our knowledge, this study represents the first use of TCRm mAbs to define the kinetics and magnitude of HLA presentation for a series of epitopes encoded by one virus, and the results depict a pattern whereby individual epitopes differ considerably in abundance and availability. The observations that immunodominant ligands can be found at lower levels and at later time points after infection suggest that a reevaluation of the factors that combine to shape T cell reactivity may be warranted.


Asunto(s)
Presentación de Antígeno , Linfocitos T CD8-positivos/inmunología , Epítopos de Linfocito T/inmunología , Epítopos Inmunodominantes/inmunología , Virus del Nilo Occidental/inmunología , Animales , Anticuerpos Monoclonales/inmunología , Especificidad de Anticuerpos , Línea Celular Tumoral , Células Dendríticas/virología , Femenino , Antígenos HLA-A/inmunología , Humanos , Ratones , Ratones Endogámicos BALB C , Receptores de Antígenos de Linfocitos T/inmunología
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