RESUMO
The host type I interferon (IFN) response protects against Legionella pneumophila infections. Other bacterial pathogens inhibit type I IFN-mediated cell signaling; however, the interaction between this signaling pathway and L. pneumophila has not been well described. Here, we demonstrate that L. pneumophila inhibits the IFN-ß signaling pathway but does not inhibit IFN-γ-mediated cell signaling. The addition of IFN-ß to L. pneumophila-infected macrophages limited bacterial growth independently of NOS2 and reactive nitrogen species. The type IV secretion system of L. pneumophila is required to inhibit IFN-ß-mediated cell signaling. Finally, we show that the inhibition of the IFN-ß signaling pathway occurs downstream of STAT1 and STAT2 phosphorylation. In conclusion, our findings describe a novel host cell signaling pathway inhibited by L. pneumophila via its type IV secretion system.
Assuntos
Interferon Tipo I , Legionella pneumophila , Doença dos Legionários , Humanos , Legionella pneumophila/fisiologia , Sistemas de Secreção Tipo IV , Interferon gama/metabolismo , Transdução de SinaisRESUMO
The production of L-lactide from L-lactic acid involves a substantial formation of meso-lactide as an impurity, and, upon polymerization with the industrial catalyst tin octanoate, results in poly(L-lactic acid) of reduced crystallinity due to stereoerrors randomly distributed along the polymer chains. We describe a new approach wherein, instead of avoiding stereoerrors by removing the meso-lactide prior to polymerization, the stereoerrors in the polymer are tolerated, by crowding them in a stereogradient copolymer. A zirconium complex of an amine tris(phenolate) ligand is found to exhibit very high syndioselectivity in the ring opening polymerization catalysis of meso-lactide at room temperature, and gives rise to stereogradient copolymers in the polymerization of mixtures of meso-lactide/L-lactide in the melt at 180 °C. Relative to the stereo-random copolymers obtained with tin octanoate, the stereogradient copolymers exhibit enhanced crystallinities manifested in lower solubilities and higher melting temperatures and enthalpies.
Assuntos
Caprilatos , Zircônio , Aminas , Dioxanos , Ácido Láctico , Ligantes , Poliésteres , Polímeros , EstanhoRESUMO
We report investigations of the use of cucurbit[8]uril (CB[8]) macrocycles as an antidote to counteract the in vivo biological effects of phencyclidine. We investigate the binding of CB[8] and its derivative Me4 CB[8] toward ten drugs of abuse (3-9, 12-14) by a combination of 1 Hâ NMR spectroscopy and isothermal titration calorimetry in phosphate buffered water. We find that the cavity of CB[8] and Me4 CB[8] are able to encapsulate the 1-amino-1-aryl-cyclohexane ring system of phencyclidine (PCP) and ketamine as well as the morphinan skeleton of morphine and hydromorphone with Kd values ≤50â nm. In vitro cytotoxicity (MTS metabolic and adenylate kinase cell death assays in HEK293 and HEPG2 cells) and in vivo maximum tolerated dose studies (Swiss Webster mice) which were performed for Me4 CB[8] indicated good tolerability. The tightest hostâ guest pair (Me4 CB[8]â PCP; Kd =2â nm) was advanced to in vivo efficacy studies. The results of open field tests demonstrate that pretreatment of mice with Me4 CB[8] prevents subsequent hyperlocomotion induction by PCP and also that treatment of animals previously dosed with PCP with Me4 CB[8] significantly reduces the locomotion levels.
Assuntos
Hidrocarbonetos Aromáticos com Pontes/química , Imidazóis/química , Fenciclidina/análise , Fenciclidina/química , Animais , Hidrocarbonetos Aromáticos com Pontes/administração & dosagem , Hidrocarbonetos Aromáticos com Pontes/farmacologia , Células HEK293 , Células Hep G2 , Humanos , Imidazóis/administração & dosagem , Imidazóis/farmacologia , Locomoção/efeitos dos fármacos , Camundongos , Fenciclidina/administração & dosagem , Fenciclidina/farmacologiaRESUMO
We report the synthesis of two new acyclic sulfated acyclic CB[n]-type receptors (TriM0 and Me4 TetM0) and investigations of their binding properties toward a panel of drugs of abuse (1-13) by a combination of 1 H NMR spectroscopy and isothermal titration calorimetry. TetM0 is the most potent receptor with Ka ≥106 â M-1 toward methamphetamine, fentanyl, MDMA and mephedrone. TetM0 is not cytotoxic toward HepG2 and HEK 293 cells below 100â µM according to MTS metabolic and adenylate kinase release assays and is well tolerated inâ vivo when dosed at 46â mg kg-1 . TetM0 does not inhibit the hERG ion channel and is not mutagenic based on the Ames fluctuation test. Finally, inâ vivo efficacy studies show that the hyperlocomotion of mice treated with methamphetamine can be greatly reduced by treatment with TetM0 up to 5â minutes later. TetM0 has potential as a broad spectrum inâ vivo sequestrant for drugs of abuse.
Assuntos
Metanfetamina , Sulfatos , Animais , Células HEK293 , Humanos , Metanfetamina/toxicidade , CamundongosRESUMO
Two organogelators of different chemistry (a fatty acid derivative and a bis-urea derivative), as well as their blends, were used to impart shape stability to a bio-based phase-change material (PCM) bearing a near-ambient phase-transition temperature. Characterization of the individual gelators and their blends revealed their ability to immobilize the PCM by forming a continuous fibrillar network. The fibrils formed by the fatty acid derivative were helical, while the bis-urea derivative formed smooth fibrils. Also, the bis-urea derivative formed a continuous network at a lower critical concentration than the fatty acid derivative. At each fixed concentration, the bis-urea derivative yielded gels with higher thermal stability than the fatty acid derivative. The two gelators blended in certain ratios demonstrated a strong synergistic effect, providing gels with a significantly higher modulus (â¼20-fold) and yield stress (â¼1.5-fold) than each gelator individually. PCM gelation did not significantly affect its thermal behavior, however, affected its crystalline morphology. The gelled PCM displayed stacked structures, consisting of alternating pure PCM layers separated by layers formed by gelator fibrils. The phase diagram of the triple system comprising both gelators and PCM demonstrated either single or double gelation behavior depending on the composition. These findings may provide guidelines for the development of novel, shape-stable PCMs, which could be of potential use in various thermal energy storage applications.
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There is surprisingly little empirical evidence supporting theoretical and anecdotal claims regarding the spontaneous production of prototypic facial expressions used in numerous emotion recognition studies. Proponents of innate prototypic expressions believe that this lack of evidence may be due to ethical restrictions against presenting powerful elicitors in the lab. The current popularity of internet platforms designed for public sharing of videos allows investigators to shed light on this debate by examining naturally-occurring facial expressions outside the laboratory. An Internet prank ("Scary Maze") has provided a unique opportunity to observe children reacting to a consistent fear- and surprise-inducing stimulus: The unexpected presentation of a "scary face" during an online maze game. The purpose of this study was to examine children's facial expressions in this naturalistic setting. Emotion ratings of non-facial behaviour (provided by untrained undergraduates) and anatomically-based facial codes were obtained from 60 videos of children (ages 4-7) found on YouTube. Emotion ratings were highest for fear and surprise. Correspondingly, children displayed more facial expressions of fear and surprise than for other emotions (e.g. anger, joy). These findings provide partial support for the ecological validity of fear and surprise expressions. Still prototypic expressions were produced by fewer than half the children.
Assuntos
Emoções , Expressão Facial , Jogos de Vídeo/psicologia , Criança , Pré-Escolar , Feminino , Humanos , Internet , MasculinoRESUMO
Background: Health-related messages, framed in terms of gains or losses, can impact decision-making differently across the adult life span. The focus of this study was on the emotional responses evoked by such framing and their relationship to perceived effectiveness, as mechanisms that may underpin how health messages impact health decisions. Methods: A web-based study using Amazon's Mechanical Turk platform was conducted with a sample of 132 younger adults and 106 older adults. Participants were asked to read exercise-related messages framed in terms of gains or losses, and to rate each message for affect and effectiveness. Results: Relative to younger adults, older adults showed less negative reactions to loss-framed messages and to messages that described undesirable outcomes. Importantly, younger and older adults differentially used affective cues to gauge effectiveness of framed messages: for gain-framed messages (which tended to evoke positive affect), older adults found messages that made them feel good to be more effective; but for loss-framed messages (which tend to evoke negative affect), younger adults found messages that made them feel bad to be more effective. Conclusions: These results suggest that in processing health messages, older adults may be more motivated by positive affect, while younger adults may be more motivated by negative affect.
Assuntos
Envelhecimento/psicologia , Emoções , Exercício Físico/psicologia , Promoção da Saúde , Adulto , Idoso , Idoso de 80 Anos ou mais , Tomada de Decisões , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Motivação , Percepção , Adulto JovemRESUMO
Accurate quantification of bacterial burden within macrophages, termed bacterial burden quantification (BBQ), is crucial for understanding host-pathogen interactions. Various methods have been employed, each with strengths and weaknesses. This article addresses limitations in existing techniques and introduces two novel, automated methods for BBQ within macrophages based on confocal microscopy data analysis. The first method refines total fluorescence quantification by incorporating filtering steps to exclude uninfected cells, while the second method calculates total bacterial volume per cell to mitigate potential biases in fluorescence-based readouts. These workflows utilize PyImageJ and Cellpose software, providing reliable, unbiased, and rapid quantification of bacterial load. The proposed workflows were validated using Salmonella enterica serovar Typhimurium and Mycobacterium tuberculosis models, demonstrating their effectiveness in accurately assessing bacterial burden. These automated workflows offer valuable tools for studying bacterial interactions within host cells and provide insights for various research applications.
Assuntos
Macrófagos , Salmonella typhimurium , Fluxo de Trabalho , Interações Hospedeiro-PatógenoRESUMO
Type I Interferons (IFNs) generally have a protective role during viral infections, but their function during bacterial infections is dependent on the bacterial species. Legionella pneumophila, Shigella sonnei and Mycobacterium tuberculosis can inhibit type I IFN signaling. Here we examined the role of type I IFN, specifically IFNß, in the context of Salmonella enterica serovar Typhimurium (STm) macrophage infections and the capacity of STm to inhibit type I IFN signaling. We demonstrate that IFNß has no effect on the intracellular growth of STm in infected bone marrow derived macrophages (BMDMs) derived from C57BL/6 mice. STm infection inhibits IFNß signaling but not IFNγ signaling in a murine macrophage cell line. We show that this inhibition is independent of the type III and type VI secretion systems expressed by STm and is also independent of bacterial phagocytosis. The inhibition is Toll-like receptor 4 (TLR4)-dependent as the TLR4 ligand, lipopolysaccharide (LPS), alone is sufficient to inhibit IFNß-mediated signaling and STm-infected, TLR4-deficient BMDMs do not exhibit inhibited IFNß signaling. In summary, we show that macrophages exposed to STm have reduced IFNß signaling via crosstalk with TLR4 signaling, and that IFNß signaling does not affect cell autonomous host defense against STm.
RESUMO
BACKGROUND: Ultrasound (US) examination has many uses in resuscitation, but to use it to its full effectiveness typically requires a trained and proficient user. We sought to use information technology advances to remotely guide US-naive examiners (UNEs) using a portable battery-powered tele-US system mentored using either a smartphone or laptop computer. MATERIALS AND METHODS: A cohort of UNEs (5 tactical emergency medicine technicians, 10 ski-patrollers, and 4 nurses) was guided to perform partial or complete Extended Focused Assessment with Sonography of Trauma (EFAST) examinations on both a healthy volunteer and on a US phantom, while being mentored by a remote examiner who viewed the US images over either an iPhone(®) (Apple, Cupertino, CA) or a laptop computer with an inlaid depiction of the US probe and the "patient," derived from a videocamera mounted on the UNE's head. Examinations were recorded as still images and over-read from a Web site by seven expert reviewers (ERs) (three surgeons, two emergentologists, and two radiologists). Examination goals were to identify lung sliding (LS) documented by color power Doppler (CPD) in the human and to identify intraperitoneal (IP) fluid in the phantom. RESULTS: All UNEs were successfully mentored to easily and clearly identify both LS (19 determinations) and IP fluid (14 determinations), as assessed in real time by the remote mentor. ERs confirmed IP fluid in 95 of 98 determinations (97%), with 100% of ERs perceiving clinical utility for the abdominal Focused Assessment with Sonography of Trauma. Based on single still CPD images, 70% of ERs agreed on the presence or absence of LS. In 16 out of 19 cases, over 70% of the ERs felt the EFAST exam was clinically useful. CONCLUSIONS: UNEs can confidently be guided to obtain critical findings using simple information technology resources, based on the receiving/transmitting device found in most trauma surgeons' pocket or briefcase. Global US mentoring requires only Internet connectivity and initiative.
Assuntos
Telefone Celular , Microcomputadores , Consulta Remota/instrumentação , Ressuscitação , Ultrassonografia , Serviços Médicos de Emergência , Estudos de Viabilidade , HumanosRESUMO
Accurate quantification of bacterial burden within macrophages, termed Bacterial Burden Quantification (BBQ), is crucial for understanding host-pathogen interactions. Various methods have been employed, each with strengths and weaknesses. This article addresses limitations in existing techniques and introduces two novel automated methods for BBQ within macrophages based on confocal microscopy data analysis. The first method refines total fluorescence quantification by incorporating filtering steps to exclude uninfected cells, while the second method calculates total bacterial volume per cell to mitigate potential biases in fluorescence-based readouts. These workflows utilize PyImageJ and Cellpose software, providing reliable, unbiased, and rapid quantification of bacterial load. The proposed workflows were validated using Salmonella enterica serovar Typhimurium and Mycobacterium tuberculosis models, demonstrating their effectiveness in accurately assessing bacterial burden. These automated workflows offer valuable tools for studying bacterial interactions within host cells and provide insights for various research applications.
RESUMO
Pillar[6]MaxQ (P6AS) functions as an in vivo sequestration agent for methamphetamine and fentanyl. We use 1H NMR, isothermal titration calorimetry, and molecular modelling to deduce the geometry and strength of the P6ASâ¢drug complexes. P6AS forms tight complexes with fentanyl (Kd=9.8 nM), PCP (17.1 nM), MDMA (25.5 nM), mephedrone (52.4 nM), and methamphetamine (101 nM). P6AS has good in vitro biocompatibility according to MTS metabolic, Adenylate Kinase cell death, and hERG ion channel inhibition assays, and the Ames fluctuation test. The no observed adverse effect level for P6AS is 45 mg/kg. The hyperlocomotion of mice treated with methamphetamine (0.5 mg/kg) can be ameliorated by treatment with P6AS (35.7 mg/kg) 5-minutes later, whereas the hyperlocomotion of mice treated with fentanyl (0.1 mg/kg) can be controlled by treatment with P6AS (5 mg/kg) up to 15-minutes later. P6AS has significant potential for development as a broad spectrum in vivo sequestration agent.
RESUMO
Interrelations among cultural values, parenting practices, and adolescent aggression were examined using longitudinal data collected from Chinese adolescents and their mothers. Adolescents' overt and relational aggression were assessed using peer nominations at Time 1 (7th grade) and Time 2 (9th grade). Mothers reported endorsement of cultural values (collectivism and social harmony) and parenting practices (psychological control and inductive reasoning) at Time 1. While controlling for Time 1 adolescent aggression, maternal collectivism and social harmony indirectly and longitudinally linked to adolescent aggression through maternal parenting practices. Specifically, maternal collectivism was positively related to inductive reasoning, which, in turn, negatively related to adolescent overt aggression at Time 2. Similarly, maternal social harmony negatively related to psychological control that positively predicted later adolescent relational aggression. Results of the present study shed light on mechanisms through which culture may indirectly influence adolescent aggression.
Assuntos
Agressão , Cultura , Relações Mãe-Filho , Poder Familiar/etnologia , Valores Sociais , Adolescente , China , Feminino , Humanos , Estudos Longitudinais , Relações Mãe-Filho/etnologia , Poder Familiar/psicologia , Controles Informais da Sociedade , Valores Sociais/etnologiaRESUMO
Blending two gelators with different chemistries (12-hydroxystearic acid and a bis-urea derivative, Millithix MT-800) was used to impart shape stability to CrodaTherm 29, a bio-based phase change material (PCM), melting/crystallizing at near-ambient temperature. The gelators immobilized the PCM by forming an interpenetrating fibrillar network. 15 wt % concentration of the gelators was found to be effective in preventing liquid PCM leakage. In order to improve the mechanical properties and thermal conductivity (TC) of the PCM, gelation of suspensions of multiwalled carbon nanotubes (MWCNTs) and graphene nanoplatelets (GnPs) in a molten material was done at concentrations exceeding their percolation thresholds. Compared to pristine PCM, the gelled PCM containing 3.0 wt % of GnPs demonstrated a shorter crystallization time, â¼1.5-fold increase in strength, improved stability, and â¼65% increase in TC. At the same time, PCM filled with up to 0.6 wt % of MWCNTs had diminished strength and increased leakage with a slight TC improvement. Gelation of PCM did not significantly alter its thermal behavior, but it did change its crystalline morphology. The developed shape-stable PCMs may have a wide range of applications in ambient temperature solar-thermal installations, for example, temperature-controlled greenhouses, net zero-energy buildings, and water heaters.
RESUMO
We report studies of the interaction of six acyclic CB[n]-type receptors toward a panel of drugs of abuse by a combination of isothermal titration calorimetry and 1 H NMR spectroscopy. Anthracene walled acyclic CB[n] host (M3) displays highest binding affinity toward methamphetamine (Kd =15â nM) and fentanyl (Kd =4â nM). Host M3 is well tolerated by Hep G2 and HEK 293 cells up to 100â µM according to MTS metabolic and adenylate kinase release assays. An inâ vivo maximum tolerated dose study with Swiss Webster mice showed no adverse effects at the highest dose studied (44.7â mg kg-1 ). Host M3 is not mutagenic based on the Ames fluctuation test and does not inhibit the hERG ion channel. In vivo efficacy studies showed that pretreatment of mice with M3 significantly reduces the hyperlocomotion after treatment with methamphetamine, but M3 does not function similarly when administered 30 seconds after methamphetamine.
Assuntos
Metanfetamina , Animais , Antracenos/farmacologia , Células HEK293 , Humanos , Dose Máxima Tolerável , Metanfetamina/farmacologia , CamundongosAssuntos
Síndrome Coronariana Aguda/terapia , Serviços Médicos de Emergência/normas , Síndrome Coronariana Aguda/sangue , Síndrome Coronariana Aguda/diagnóstico , Difosfato de Adenosina , Adulto , Biomarcadores/sangue , Angiografia Coronária/normas , Diagnóstico por Computador , Eletrocardiografia , Serviços Médicos de Emergência/métodos , Fibrinolíticos/uso terapêutico , Humanos , Reperfusão Miocárdica/métodos , Reperfusão Miocárdica/normas , Revascularização Miocárdica/normas , Oxigenoterapia , Transferência de Pacientes/normas , Sensibilidade e Especificidade , Troponina/sangueAssuntos
Reanimação Cardiopulmonar/normas , Serviços Médicos de Emergência/normas , Medicina Baseada em Evidências/métodos , Parada Cardíaca/terapia , Guias de Prática Clínica como Assunto , American Heart Association , Conflito de Interesses , Consenso , Previsões , Humanos , Armazenamento e Recuperação da Informação , Internet , Literatura de Revisão como Assunto , Estados UnidosRESUMO
In summary, the evidence review process has attempted to provide a systematic review of the scientific literature using a priori defined methods. The details and steps of the literature review are transparent and replicable. External opinions and community critique are highly valued, and the final products represent the combined labor of hundreds of participants.
Assuntos
American Heart Association , Reanimação Cardiopulmonar/ética , Conflito de Interesses , Medicina Baseada em Evidências/ética , Guias de Prática Clínica como Assunto , Cardiologia/ética , Cardiologia/normas , Reanimação Cardiopulmonar/normas , Serviços Médicos de Emergência/ética , Serviços Médicos de Emergência/normas , Medicina Baseada em Evidências/normas , Humanos , Percepção , Guias de Prática Clínica como Assunto/normas , Estados UnidosRESUMO
The goal of therapy for bradycardia or tachycardia is to rapidly identify and treat patients who are hemodynamically unstable or symptomatic due to the arrhythmia. Drugs or, when appropriate, pacing may be used to control unstable or symptomatic bradycardia. Cardioversion or drugs or both may be used to control unstable or symptomatic tachycardia. ACLS providers should closely monitor stable patients pending expert consultation and should be prepared to aggressively treat those with evidence of decompensation.