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1.
N Engl J Med ; 388(22): 2025-2036, 2023 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-37256974

RESUMEN

BACKGROUND: The effects of the glycoprotein IIb/IIIa receptor inhibitor tirofiban in patients with acute ischemic stroke but who have no evidence of complete occlusion of large or medium-sized vessels have not been extensively studied. METHODS: In a multicenter trial in China, we enrolled patients with ischemic stroke without occlusion of large or medium-sized vessels and with a National Institutes of Health Stroke Scale score of 5 or more and at least one moderately to severely weak limb. Eligible patients had any of four clinical presentations: ineligible for thrombolysis or thrombectomy and within 24 hours after the patient was last known to be well; progression of stroke symptoms 24 to 96 hours after onset; early neurologic deterioration after thrombolysis; or thrombolysis with no improvement at 4 to 24 hours. Patients were assigned to receive intravenous tirofiban (plus oral placebo) or oral aspirin (100 mg per day, plus intravenous placebo) for 2 days; all patients then received oral aspirin until day 90. The primary efficacy end point was an excellent outcome, defined as a score of 0 or 1 on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]) at 90 days. Secondary end points included functional independence at 90 days and a quality-of-life score. The primary safety end points were death and symptomatic intracranial hemorrhage. RESULTS: A total of 606 patients were assigned to the tirofiban group and 571 to the aspirin group. Most patients had small infarctions that were presumed to be atherosclerotic. The percentage of patients with a score of 0 or 1 on the modified Rankin scale at 90 days was 29.1% with tirofiban and 22.2% with aspirin (adjusted risk ratio, 1.26; 95% confidence interval, 1.04 to 1.53, P = 0.02). Results for secondary end points were generally not consistent with the results of the primary analysis. Mortality was similar in the two groups. The incidence of symptomatic intracranial hemorrhage was 1.0% in the tirofiban group and 0% in the aspirin group. CONCLUSIONS: In this trial involving heterogeneous groups of patients with stroke of recent onset or progression of stroke symptoms and nonoccluded large and medium-sized cerebral vessels, intravenous tirofiban was associated with a greater likelihood of an excellent outcome than low-dose aspirin. Incidences of intracranial hemorrhages were low but slightly higher with tirofiban. (Funded by the National Natural Science Foundation of China; RESCUE BT2 Chinese Clinical Trial Registry number, ChiCTR2000029502.).


Asunto(s)
Fibrinolíticos , Accidente Cerebrovascular Isquémico , Tirofibán , Humanos , Aspirina/efectos adversos , Isquemia Encefálica/tratamiento farmacológico , Isquemia Encefálica/etiología , Fibrinolíticos/efectos adversos , Fibrinolíticos/uso terapéutico , Hemorragias Intracraneales/inducido químicamente , Accidente Cerebrovascular Isquémico/diagnóstico , Accidente Cerebrovascular Isquémico/tratamiento farmacológico , Accidente Cerebrovascular Isquémico/etiología , Inhibidores de Agregación Plaquetaria/efectos adversos , Inhibidores de Agregación Plaquetaria/uso terapéutico , Tirofibán/efectos adversos , Tirofibán/uso terapéutico , Resultado del Tratamiento , Enfermedades Arteriales Cerebrales/tratamiento farmacológico , Enfermedades Arteriales Cerebrales/etiología
2.
Child Dev ; 95(1): 114-127, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37417935

RESUMEN

The present study examined relations between concern for mianzi, or the social perception of one's prestige and standing in the group, and adjustment in Chinese adolescents. Participants were seventh- and ninth-grade students in rural and urban regions of China (n = 794, Mage = 14 years). Data were obtained from multiple sources including peer assessments, teacher ratings, self-reports, and school records. The results showed that concern for mianzi was associated with social competence, leadership, academic achievement, as well as aggression and mixed peer relationships in rural adolescents. In contrast, concern for mianzi was associated with comprehensive social, school, and psychological adjustment problems in urban adolescents. The results indicate the role of context in shaping the relations between adolescents' concern for mianzi and adjustment.


Asunto(s)
Éxito Académico , Ajuste Social , Humanos , Adolescente , Ajuste Emocional , Instituciones Académicas , Escolaridad , Grupo Paritario , China
3.
Child Dev ; 95(1): e21-e34, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37561124

RESUMEN

Loneliness is a perceived deficit in social relationships that is nested within broader cultural meaning systems. This longitudinal study examined predictors of loneliness in Chinese and U.S. children with the hypothesis that peer relationship parameters (number of friends, social preference, and popularity) mediate the associations between behavior qualities and loneliness differently across countries. Fifth-grade Chinese (n = 576, Mage = 10.58 years) and U.S. (White, Black, Asian, n = 540; Mage = 10.23 years) children completed two waves of assessment within an academic year. Shyness and athletic competence more strongly predicted loneliness for U.S. children, and academic ability, and aggression more strongly predicted loneliness for Chinese children. Popularity was a mediator for U.S. children but not Chinese children.


Asunto(s)
Relaciones Interpersonales , Soledad , Niño , Humanos , Estados Unidos , Estudios Longitudinales , Grupo Paritario , China
4.
J Youth Adolesc ; 53(3): 621-631, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38032413

RESUMEN

Adolescents use various strategies to help their victimized peers during bullying episodes. However, prior research has primarily adopted a variable-centered approach that examines the effect of each defending strategies separately and does not address whether there were different types of defenders who exhibit specific combinations of defending strategies and how these profiles related to youth's adjustment outcomes. Using latent profile analysis, this study identified defending profiles among a sample of Chinese adolescents (N = 1618, Mage = 13.81, SDage = 0.94, 42% girls) and examined whether these profiles differ on victimization experiences and depressive symptoms. The results yielded four defending profiles: nonaggressive defenders (15%), aggressive defenders (7%), average defenders (54%), and infrequent defenders (24%). Aggressive defenders and infrequent defenders exhibited the highest levels of self-reported victimization and depressive symptoms, whereas nonaggressive defenders demonstrated the lowest. There were no statistical profile differences in peer-reported victimization. Findings suggest that investigating the heterogeneity of youth using defending strategies is important for understanding whether defending actually puts youth at increased risk for negative adjustment.


Asunto(s)
Acoso Escolar , Víctimas de Crimen , Femenino , Humanos , Adolescente , Lactante , Masculino , Depresión , Grupo Paritario , Agresión
5.
J Youth Adolesc ; 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38750312

RESUMEN

Leadership in peer groups is an important issue in adolescent socioemotional development, yet it has received limited attention in research. This one-year longitudinal study examined peer group leadership and the roles of social, academic, and psychological characteristics in the dynamics of group leadership. Participants included 1061 Chinese students (initial mean age =11.17 years; SD = 6.98 months; 49.4% female). Data were collected from peer assessments, teacher ratings, and self-reports. The longitudinal social network analysis (SIENA) indicated that peer group leadership was fluid with leadership status evolving over time across groups in a hierarchical manner. Adolescents displaying higher social competence and aggression and lower shyness were more likely to become group leaders. Academic performance and loneliness were not significantly associated with the dynamics of peer group leadership. The results help understand peer group leadership and contributions of social behaviors to the attainment of leadership status in peer groups in early adolescence.

6.
Microb Pathog ; 185: 106447, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37972742

RESUMEN

Listeria monocytogenes, a foodborne pathogen that causes listeriosis with high fatality rate, exhibits multidrug resistance (MDR) known to be progressively increasing. Alternative antibacterial strategies are in high demand for treating this well-known pathogen. Anti-biofilm and anti-virulence strategies are being explored as novel approaches to treat bacterial infections. In this study, one rare antibacterial named setomimycin was isolated from Streptomyces cyaneochromogenes, which showed potent antibacterial activity against L. monocytogenes. Next, the inhibition of biofilm formation and listeriolysin O (LLO) production against L. monocytogenes were investigated at sub-minimal inhibitory concentrations (sub-MICs) of setomimycin alone or combined with kanamycin and amikacin. Crystal violet staining confirmed that setomimycin combining with kanamycin or amikacin could dramatically reduce biofilm formation against L. monocytogenes at sub-MICs, which was further evaluated by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). In the meantime, sub-MICs of setomimycin could significantly suppress the secretion of LLO. Furthermore, the transcription of genes associated with biofilms and main virulence factors, such as LLO, flagellum, and metalloprotease, were suppressed by setomimycin at sub-MICs. Hence, the study provided a deep insight into setomimycin as an alternative antibacterial agent against L. monocytogenes.


Asunto(s)
Listeria monocytogenes , Listeriosis , Humanos , Amicacina/farmacología , Kanamicina/farmacología , Listeriosis/microbiología , Biopelículas , Antibacterianos/farmacología , Proteínas Hemolisinas/genética
7.
Crit Rev Food Sci Nutr ; 63(20): 4217-4234, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-35389274

RESUMEN

Glucosinolates and their metabolites from Brassicaceae plants have received widespread attention due to their anti-inflammatory effects. Glucosinolates occurs an "enterohepatic circulation" in the body, and the glucosinolates metabolism mainly happens in the intestine. Glucosinolates can be converted into isothiocyanates by intestinal bacteria, which are active substances with remarkable anti-inflammatory, anti-cancer, anti-obesity and neuroprotective properties. This biotransformation can greatly improve the bioactivities of glucosinolates. However, multiple factors in the environment can affect the biotransformation to isothiocyanates, including acidic pH, ferrous ions and thiocyanate-forming protein. The derivatives of glucosinolates under those conditions are usually nitriles and thiocyanates, which may impair the potential health benefits. In addition, isothiocyanates are extremely unstable because of an active sulfhydryl group, which limits their applications. This review mainly summarizes the classification, synthesis, absorption, metabolism, physiological functions and potential application strategies of glucosinolates and their metabolites.


Asunto(s)
Brassicaceae , Glucosinolatos , Glucosinolatos/metabolismo , Glicósido Hidrolasas/metabolismo , Brassicaceae/química , Brassicaceae/metabolismo , Isotiocianatos/metabolismo , Antiinflamatorios/metabolismo
8.
Child Dev ; 94(2): 348-362, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36254836

RESUMEN

This 1-year longitudinal study examined the effects of academic performance and depression in friendships among elementary school children in China. Participants included 1122 children (44% boys) within 561 stable friendship dyads initially in fourth and fifth grades (initial Mage  = 11 years). Data on academic performance, depression, and friendship were collected from multiple sources in the period of 2012 to 2014. Dyadic analysis using the actor-partner interdependence model showed that friends' academic performance significantly and positively predicted children's later academic performance, indicating same-domain effects, and significantly and negatively predicted children's later depression, indicating cross-domain effects, with a medium effect size (ε3  = .70) for the effects of academic performance. The results help understand the role of friendship in children's development in the Chinese context.


Asunto(s)
Rendimiento Académico , Amigos , Masculino , Humanos , Niño , Femenino , Relaciones Interpersonales , Depresión , Estudios Longitudinales , Grupo Paritario
9.
Child Dev ; 94(1): 126-141, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36017533

RESUMEN

This 2-year longitudinal study examined relations between enjoyment of learning in Chinese and mathematics, two major subjects in Chinese schools, and indexes of school performance. The participants included 1041 students (501 boys) initially in third, fifth, and seventh grades (mean age = 10.49 years) in China. Data on enjoyment of Chinese and mathematics were collected from students' self-reports and data on school performance were collected from multiple sources in 2017 and 2019. The results showed that enjoyment of mathematics positively predicted later academic achievement, self-perceptions of academic competence, teacher-rated school competence, and peer-assessed leadership-social competence. Enjoyment of Chinese negatively predicted later mathematics achievement and self-perceptions of academic competence and nonsignificantly predicted other school performance variables. The results were discussed in Chinese context.


Asunto(s)
Pueblos del Este de Asia , Placer , Masculino , Humanos , Niño , Adolescente , Estudios Longitudinales , Felicidad , Matemática
10.
J Exp Child Psychol ; 233: 105692, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37163827

RESUMEN

According to recent accounts, bilingualism in childhood confers an advantage in a specific domain of executive functioning termed attentional disengagement. The current study tested this hypothesis in 492 children (245 boys; Mage = 10.98 years) from Canada, China, and Lebanon by testing for an association between language status and measures of attentional disengagement. Across the entire sample, monolinguals responded more quickly and accurately than bilinguals on a measure of attentional disengagement but differed in age, socioeconomic status, and general cognitive ability. Differences between monolinguals and bilinguals disappeared when the influence of these confounding variables was controlled using a matched samples analysis (ns = 105). Bayesian analyses further confirmed that the evidence was more likely under the null hypothesis than under the alternative hypothesis. In sum, there was little evidence of an association between language status and attentional disengagement in children.


Asunto(s)
Atención , Multilingüismo , Masculino , Humanos , Niño , Teorema de Bayes , Función Ejecutiva , Lenguaje
11.
J Res Adolesc ; 33(4): 1391-1406, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37712872

RESUMEN

The current study examined the idea that maternal involvement during the COVID-19 school closure period could contribute to the development of adolescents' daily routines, which could ultimately associate with their psychological and academic adjustment after return-to-school. Data were collected from 520 Chinese adolescents (Mage = 12.75 years, SDage = 1.48 years) and their mothers during the COVID-19 school closure and one year after return-to-school. Results indicated that maternal involvement in both education and leisure activities predicted more consistent adolescents' daily routines during the school closure period and then contributed to their more consistent daily routines after return-to-school, resulting in less psychological maladjustment and better academic outcomes. Findings highlight the importance of maternal involvement and daily routines in the context of COVID-19.


Asunto(s)
COVID-19 , Femenino , Humanos , Adolescente , Niño , Lactante , Estudios Longitudinales , Madres/psicología , Instituciones Académicas , Organizaciones
12.
Molecules ; 28(9)2023 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-37175254

RESUMEN

L-theanine (N-ethyl-γ-glutamine) is the main amino acid in tea leaves. It not only contributes to tea flavor but also possesses several health benefits. Compared with its sedative and calming activities, the immunomodulatory effects of L-theanine have received less attention. Clinical and epidemiological studies have shown that L-theanine reduces immunosuppression caused by strenuous exercise and prevents colds and influenza by improving immunity. Numerous cell and animal studies have proven that theanine plays an immunoregulatory role in inflammation, nerve damage, the intestinal tract, and tumors by regulating γδT lymphocyte function, glutathione (GSH) synthesis, and the secretion of cytokines and neurotransmitters. In addition, theanine can be used as an immunomodulator in animal production. This article reviews the research progress of L-theanine on immunoregulation and related mechanisms, as well as its application in poultry and animal husbandry. It is hoped that this work will be beneficial to future related research.


Asunto(s)
Citocinas , Glutamatos , Animales , Glutamatos/química , Inmunidad , Té/química
13.
J Youth Adolesc ; 52(3): 670-683, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36495392

RESUMEN

Popularity has been empirically linked to psychological and several indices of school adjustment outcomes during childhood and early adolescence. Yet, best friend popularity in relation to the adjustment outcomes remains unclear, especially in more interdependent-oriented cultures. To address this gap, this study applied the Actor-Partner Interdependence Model (APIM) to simultaneously considering whether, and how, the popularity of youth (actor effects) and their best friends (partner effects) contribute uniquely to psychological well-being and school adjustment outcomes, after controlling for social preference. Age and gender differences were also examined. Participants were 162 same-gender best friend dyads (81 boys, Mage = 11.24 years, SD = 1.18) from Shanghai, P.R. China. Among the results, both youth's own and their best friends' popularity were positively related to self-esteem and school attitudes, and negatively related to depressive symptoms. In addition, results from multi-group analyses revealed both actor and partner effects did not vary across gender. Finally, exploratory analyses showed that only actor effects varied across age for the associations between popularity and self-esteem and school attitudes. These findings highlight the important role of the best friend's popularity in promoting Chinese youth's experiences of psychological and school adjustment.


Asunto(s)
Amigos , Bienestar Psicológico , Masculino , Humanos , Adolescente , Niño , Amigos/psicología , China , Adaptación Psicológica , Instituciones Académicas
14.
Water Sci Technol ; 88(7): 1795-1820, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37830997

RESUMEN

The impact of Ba-modified peanut shell biochar (Ba-PSB) on Pb(II) removal was studied and BaCl2 was used as a modifier. It was shown that the PSB obtained at 750 °C had the best adsorption effect, and the Ba-PSB had a larger specific surface area and a good adsorption effect on Pb(II). At pH = 5, concentration was 400 mg/L, time was 14 h, and temperature was 55 °C, the loading amount of black peanut shell biochar (BPSB), red peanut shell biochar (RPSB), Ba-BPSB, and Ba-RPSB reached 128.050, 98.217, 379.330, and 364.910 mg/g, respectively. In addition, based on the non-linear fitting, it was found that the quasi-second-order kinetic model, and isothermal model could be applied to describe Pb(II) adsorption on PSB and Ba-PSB. The adsorption behavior of PSB unmodified and modified was a spontaneous process. Moreover, chemical modification of BPSB, RPSB, Ba-BPSB, and Ba-RPSB for hindering of -COOH and -OH groups revealed 81.81, 77.08, 86.90, and 83.65% removal of Pb(II), respectively, which was due to the participation of -COOH, while 17.61, 21.70, 12.77, and 15.06% was from -OH group, respectively. The increase of cation strength (Na+, K+, Ca2+, and Mg2+) will reduce the adsorption capacity of PSB for Pb(II).


Asunto(s)
Arachis , Contaminantes Químicos del Agua , Plomo , Adsorción , Agua , Carbón Orgánico , Contaminantes Químicos del Agua/análisis , Cinética
15.
Curr Psychol ; : 1-12, 2023 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-36684461

RESUMEN

The sudden outbreak of COVID-19 and consequent quarantine policies have substantially altered family lives worldwide. Potential associations between parental negative emotional expressions towards the pandemic, family factors, and child psychological adjustment remain under-explored. Accordingly, the goal of the present study was to examine the relation between maternal panic over COVID-19 and children's depressive symptoms, with a focus on the potential moderating role of children's daily routines during a period of strict quarantine. Participants were N = 1,589 children (M age = 13.13 years, SD = 1.54; 50.7% girls) and their mothers, from Zhengzhou, Henan Province, in Mainland China. Data were collected in April of 2020, when school closure policies were in effect. Mothers reported their panic over COVID-19 and children reported their depressive symptoms and daily routines during the quarantine period. Overall, results indicated a significant positive association between maternal panic over COVID-19 and child depressive symptoms. However, maintaining regular daily routines was found to be a significant moderator of this association, with higher levels of daily routines attenuating the link between maternal panic reactions and child psychological distress (i.e., buffering effect). The results highlight the protective role of regular daily routines in promoting psychological adjustment among Chinese children during the COVID-19 pandemic. Supplementary Information: The online version contains supplementary material available at 10.1007/s12144-022-04129-0.

16.
Fam Process ; 61(4): 1749-1766, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-34939189

RESUMEN

The present study explored the role of parenting styles as mediating mechanisms in the link between marital conflict and Chinese children's internalizing problems. Participants were N = 1269 families (mothers, fathers, and children) from Shanghai, P. R. China. Multisource assessments were employed at three time points. Mothers and fathers reported their marital conflict and parenting styles (authoritative, authoritarian) and teachers and children reported on children's internalizing problems. Results from the Actor-Partner Interdependence Model (APIM) showed significant actor and partner effects for associations between marital conflict and parenting styles. After controlling for internalizing problems at Time 1, only maternal authoritarian parenting continued to mediate the relations between mothers' reported marital conflict and change in children's internalizing problems over time. This research provides valuable information about how important aspects of parenting influence the relations between marital conflict and internalizing problems among Chinese children.


Asunto(s)
Pueblos del Este de Asia , Madres , Niño , Femenino , Humanos , China
17.
J Youth Adolesc ; 51(9): 1858-1871, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35639303

RESUMEN

Although psychologically controlling and autonomy-supportive parenting are important indicators of social anxiety during early adolescence, less research has explored distinct roles of father and mother parenting, especially in interdependent-oriented culture. This 3-year longitudinal study examined the reciprocal associations between such parenting and early adolescent social anxiety from multi-informants in the Chinese context. A sample of 1,140 Chinese early adolescents (51.1% boys; Mage = 10.50 years) and their parents participated at Wave 1. The results did not reveal reciprocal relations between fathers' reported parenting and social anxiety, but indicated paternal parenting effects from boys' perceptions of autonomy support to social anxiety, and child effects from social anxiety to girls' perceived psychological control. Maternal parenting effects were present for boys' perceptions of autonomy support and girls' perceptions of psychological control. The findings highlight the distinct roles of father and mother parenting across child gender and suggest differentiated relations of parenting to social anxiety during early adolescence in the Chinese context.


Asunto(s)
Madres , Responsabilidad Parental , Adolescente , Ansiedad , Niño , Padre/psicología , Femenino , Humanos , Estudios Longitudinales , Masculino , Madres/psicología , Responsabilidad Parental/psicología
18.
J Youth Adolesc ; 51(5): 956-966, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-34590197

RESUMEN

Despite empirical findings that prosociality is related to decreased depressive symptoms in children, little is known about the directionality of the relations and the mechanisms that may explain the relations. To address these gaps, this study examined bi-directional associations between prosociality and depressive symptoms and the mediating effects of peer preference on the associations in Chinese children. Multi-wave longitudinal data were collected each year from Grades 3 to 6 in a sample of children in China (initial N = 1012; 51.6% girls; initial Mage = 8.68 years). The results showed that prosociality and depression negatively contributed to each other over time. Prosociality also predicted increased peer preference, which in turn contributed to fewer depressive symptoms, suggesting that peer preference was a mediator of the contributions of prosociality to depressive symptoms. These findings indicate the temporal ordering of prosociality and depressive symptoms and the processes in the development of depressive symptoms in Chinese children.


Asunto(s)
Depresión , Grupo Paritario , Pueblo Asiatico , Niño , China , Femenino , Humanos , Estudios Longitudinales , Masculino
19.
J Youth Adolesc ; 51(5): 904-914, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35286529

RESUMEN

Preferring to spend time alone (for any reason) has been empirically linked to symptoms of internalizing problems among Chinese children and early adolescents. However, little is known about the implications of affinity for solitude (i.e., an enjoyment of solitude) in China. Moreover, it remains unclear how affinity for solitude and depressive symptoms development simultaneously in early adolescence. To address these gaps, this study examined the longitudinal and parallel associations between affinity for solitude and depressive symptoms among Chinese early adolescents. Participants were 853 adolescents (48.4% female; Mage = 14.65 years, SD = 0.54) from mainland China followed over three years from Grade 7 to Grade 9. Assessments of affinity for solitude and depressive symptoms were obtained each year via adolescent self-reports. Among the findings, results from parallel latent growth modeling suggested that higher initial levels of affinity for solitude in Grade7 negatively predicted the slope of adolescents' depressive symptoms. This indicates that higher levels of affinity for solitude in Grade 7 predicted a slower increase in adolescents' depressive symptoms levels over three years. Implications are discussed that consider the adaptive mechanism of affinity for solitude among Chinese adolescents in the development of depressive symptoms.


Asunto(s)
Pueblo Asiatico , Depresión , Adolescente , Niño , China , Femenino , Humanos , Estudios Longitudinales , Masculino
20.
World J Microbiol Biotechnol ; 38(10): 170, 2022 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-35904625

RESUMEN

The infections caused by Pseudomonas aeruginosa are difficult to treat due to its multidrug resistance. A promising strategy for controlling P. aeruginosa infection is targeting the quorum sensing (QS) system. Actinomycin D isolated from the metabolite of endophyte Streptomyces cyaneochromogenes RC1 exhibited good anti-QS activity against P. aeruginosa PAO1. Actinomycin D (50, 100, and 200 µg/mL) significantly inhibited the motility as well as reduced the production of multiple virulence factors including pyocyanin, protease, rhamnolipid, and siderophores. The images of confocal laser scanning microscopy and scanning electron microscopy revealed that the treatment of actinomycin D resulted in a looser and flatter biofilm structure. Real-time quantitative PCR analysis showed that the expression of QS-related genes lasI, rhlI, rhlR, pqsR, pslA, and pilA were downregulated dramatically. The production of QS signaling molecules N-(3-oxododecanoyl)-L-homoserine lactone and N-butanoyl-L-homoserine lactone were also decreased by actinomycin D. These findings suggest that actinomycin D, a potent in vitro anti-virulence agent, is a promising candidate to treat P. aeruginosa infection by interfering with the QS systems.


Asunto(s)
Percepción de Quorum , Streptomyces , Antibacterianos/metabolismo , Antibacterianos/farmacología , Proteínas Bacterianas/metabolismo , Biopelículas , Dactinomicina/metabolismo , Dactinomicina/farmacología , Endófitos/metabolismo , Pseudomonas aeruginosa/metabolismo , Streptomyces/genética , Streptomyces/metabolismo , Factores de Virulencia/genética
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