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1.
PLoS Pathog ; 19(9): e1011658, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37747879

RESUMEN

Type 2 cytokines like IL-4 are hallmarks of helminth infection and activate macrophages to limit immunopathology and mediate helminth clearance. In addition to cytokines, nutrients and metabolites critically influence macrophage polarization. Choline is an essential nutrient known to support normal macrophage responses to lipopolysaccharide; however, its function in macrophages polarized by type 2 cytokines is unknown. Using murine IL-4-polarized macrophages, targeted lipidomics revealed significantly elevated levels of phosphatidylcholine, with select changes to other choline-containing lipid species. These changes were supported by the coordinated up-regulation of choline transport compared to naïve macrophages. Pharmacological inhibition of choline metabolism significantly suppressed several mitochondrial transcripts and dramatically inhibited select IL-4-responsive transcripts, most notably, Retnla. We further confirmed that blocking choline metabolism diminished IL-4-induced RELMα (encoded by Retnla) protein content and secretion and caused a dramatic reprogramming toward glycolytic metabolism. To better understand the physiological implications of these observations, naïve or mice infected with the intestinal helminth Heligmosomoides polygyrus were treated with the choline kinase α inhibitor, RSM-932A, to limit choline metabolism in vivo. Pharmacological inhibition of choline metabolism lowered RELMα expression across cell-types and tissues and led to the disappearance of peritoneal macrophages and B-1 lymphocytes and an influx of infiltrating monocytes. The impaired macrophage activation was associated with some loss in optimal immunity to H. polygyrus, with increased egg burden. Together, these data demonstrate that choline metabolism is required for macrophage RELMα induction, metabolic programming, and peritoneal immune homeostasis, which could have important implications in the context of other models of infection or cancer immunity.


Asunto(s)
Interleucina-4 , Activación de Macrófagos , Animales , Ratones , Colina/metabolismo , Citocinas/metabolismo , Interleucina-4/metabolismo , Macrófagos , Ratones Endogámicos C57BL , Regulación hacia Arriba
2.
Proc Natl Acad Sci U S A ; 119(51): e2214285119, 2022 12 20.
Artículo en Inglés | MEDLINE | ID: mdl-36512503

RESUMEN

The act of remembering an everyday experience influences how we interpret the world, how we think about the future, and how we perceive ourselves. It also enhances long-term retention of the recalled content, increasing the likelihood that it will be recalled again. Unfortunately, the ability to recollect event-specific details and reexperience the past tends to decline with age. This decline in recollection may reflect a corresponding decrease in the distinctiveness of hippocampal memory representations. Despite these well-established changes, there are few effective cognitive behavioral interventions that target real-world episodic memory. We addressed this gap by developing a smartphone-based application called HippoCamera that allows participants to record labeled videos of everyday events and subsequently replay, high-fidelity autobiographical memory cues. In two experiments, we found that older adults were able to easily integrate this noninvasive intervention into their daily lives. Using HippoCamera to repeatedly reactivate memories for real-world events improved episodic recollection and it evoked more positive autobiographical sentiment at the time of retrieval. In both experiments, these benefits were observed shortly after the intervention and again after a 3-mo delay. Moreover, more detailed recollection was associated with more differentiated memory signals in the hippocampus. Thus, using this smartphone application to systematically reactivate memories for recent real-world experiences can help to maintain a bridge between the present and past in older adults.


Asunto(s)
Memoria Episódica , Teléfono Inteligente , Humanos , Anciano , Recuerdo Mental/fisiología , Hipocampo/fisiología , Señales (Psicología)
3.
J Lipid Res ; 65(6): 100564, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38762124

RESUMEN

Metabolic programming underpins inflammation and liver macrophage activation in the setting of chronic liver disease. Here, we sought to identify the role of an important metabolic regulator, AMP-activated protein kinase (AMPK), specifically within myeloid cells during the progression of non-alcoholic steatohepatitis (NASH) and whether treatment with metformin, a firstline therapy for diabetes and activator of AMPK could stem disease progression. Male and female Prkaa1fl/fl/Prkaa2fl/fl (Flox) control and Flox-LysM-Cre+ (MacKO) mice were fed a low-fat control or a choline-deficient, amino acid defined 45% Kcal high-fat diet (CDAHFD) for 8 weeks, where metformin was introduced in the drinking water (50 or 250 mg/kg/day) for the last 4 weeks. Hepatic steatosis and fibrosis were dramatically increased in response to CDAHFD-feeding compared to low-fat control. While myeloid AMPK signaling had no effect on markers of hepatic steatosis or circulating markers, fibrosis as measured by total liver collagen was significantly elevated in livers from MacKO mice, independent of sex. Although treatment with 50 mg/kg/day metformin had no effect on any parameter, intervention with 250 mg/kg/day metformin completely ameliorated hepatic steatosis and fibrosis in both male and female mice. While the protective effect of metformin was associated with lower final body weight, and decreased expression of lipogenic and Col1a1 transcripts, it was independent of myeloid AMPK signaling. These results suggest that endogenous AMPK signaling in myeloid cells, both liver-resident and infiltrating, acts to restrict fibrogenesis during CDAHFD-induced NASH progression but is not the mechanism by which metformin improves markers of NASH.


Asunto(s)
Proteínas Quinasas Activadas por AMP , Dieta Alta en Grasa , Metformina , Enfermedad del Hígado Graso no Alcohólico , Transducción de Señal , Animales , Metformina/farmacología , Metformina/uso terapéutico , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/patología , Enfermedad del Hígado Graso no Alcohólico/etiología , Ratones , Dieta Alta en Grasa/efectos adversos , Proteínas Quinasas Activadas por AMP/metabolismo , Masculino , Femenino , Transducción de Señal/efectos de los fármacos , Células Mieloides/metabolismo , Células Mieloides/efectos de los fármacos , Cirrosis Hepática/metabolismo , Cirrosis Hepática/tratamiento farmacológico , Cirrosis Hepática/patología , Cirrosis Hepática/inducido químicamente , Ratones Endogámicos C57BL , Hígado/metabolismo , Hígado/efectos de los fármacos , Hígado/patología
4.
Hippocampus ; 34(4): 197-203, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38189156

RESUMEN

Tau pathology accumulates in the perirhinal cortex (PRC) of the medial temporal lobe (MTL) during the earliest stages of the Alzheimer's disease (AD), appearing decades before clinical diagnosis. Here, we leveraged perceptual discrimination tasks that target PRC function to detect subtle cognitive impairment even in nominally healthy older adults. Older adults who did not have a clinical diagnosis or subjective memory complaints were categorized into "at-risk" (score <26; n = 15) and "healthy" (score ≥26; n = 23) groups based on their performance on the Montreal Cognitive Assessment. The task included two conditions known to recruit the PRC: faces and complex objects (greebles). A scene condition, known to recruit the hippocampus, and a size control condition that does not rely on the MTL were also included. Individuals in the at-risk group were less accurate than those in the healthy group for discriminating greebles. Performance on either the face or size control condition did not predict group status above and beyond that of the greeble condition. Visual discrimination tasks that are sensitive to PRC function may detect early cognitive decline associated with AD.


Asunto(s)
Enfermedad de Alzheimer , Disfunción Cognitiva , Humanos , Anciano , Lóbulo Temporal/patología , Hipocampo , Percepción Visual , Discriminación en Psicología , Enfermedad de Alzheimer/patología , Imagen por Resonancia Magnética , Disfunción Cognitiva/patología
5.
Psychosom Med ; 86(2): 99-106, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37982542

RESUMEN

OBJECTIVE: Loneliness is linked to interleukin 6 (IL-6), a marker of systemic inflammation, which chronically has deleterious effects on physical and mental health across the adult life span. This study investigated cross-sectional relationships among loneliness, IL-6, demographics, multimorbidity, depression, obesity, friendship quantity, and slowed gait. METHODS: Data from the Midlife Development in the United States Biomarker Project, a national adult sample ( N = 822; age range, 26-78 years) was used for this study. The PROCESS macro tested the hypothesis that IL-6 would mediate the relationship between loneliness and gait, after adjusting for demographic and health risk factors. RESULTS: Age ( ß = 0.292, p < .001), sex ( ß = 0.197, p < .001), body mass index (BMI, ß = 0.374, p < .001), waist-hip ratio ( ß = 0.242, p < .001), and loneliness ( ß = 0.089, p = .025) but not multimorbidity ( ß = 0.043, p = .20), depression history ( ß = 0.022, p = .47), depression symptoms ( ß = 0.036, p = .28), and number of friends ( ß = 0.022, p = .46) contributed to the variance in IL-6. Serial mediation analyses supported the chained effect of loneliness on walking time through BMI and IL-6. Results also showed specific indirect effects of BMI and IL-6 on walking time, suggesting more than one pathway by which loneliness influences health. CONCLUSIONS: These results suggest that loneliness may increase the risk of systemic inflammation, leading to slowed gait and adverse health outcomes. Psychosocial interventions that address loneliness may provide an optimal treatment target for reducing inflammation and preventing declines in health.


Asunto(s)
Soledad , Velocidad al Caminar , Adulto , Humanos , Persona de Mediana Edad , Anciano , Soledad/psicología , Interleucina-6 , Inflamación , Factores de Riesgo , Depresión/psicología
6.
Inorg Chem ; 63(22): 10221-10229, 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38780069

RESUMEN

The reaction of equimolar trimethylsilyldiazomethyllithium (LiTMSD) with high spin (S = 2) PhB(AdIm)3FeCl (PhB(AdIm)3- = tris(3-adamantylimidazol-2-ylidene)phenylborate) affords the corresponding N-nitrilimido complex PhB(AdIm)3Fe-N═N═C(SiMe3). This complex can be converted to the thermodynamically more favorable C-isocyanoamido isomer PhB(AdIm)3Fe-C═N═N(SiMe3) by reaction with an additional equivalent of LiTMSD. While the iron(II) complexes are four-coordinate, the diazomethane is bound side-on in the iron(I) congener PhB(AdIm)3Fe(N,N'-κ2-N2C(H)Si(CH3)3). The latter complex adopts high spin (S = 3/2) ground state and features an unusually weak C-H bond. Photolysis of the iron(II) complexes induces N═N bond cleavage, with the iron(II) cyanide PhB(AdIm)3Fe-C≡N and iron(IV) nitride PhB(AdIm)3Fe≡N complexes being the major products of the reaction. The same products are obtained when the iron(I) complex is photolyzed or treated with a fluoride source. The trimethylsilyldiazomethane-derived ligand disassembly reactions are contrasted with those observed for related tris(carbene)amine complexes.

7.
Cereb Cortex ; 33(6): 3265-3283, 2023 03 10.
Artículo en Inglés | MEDLINE | ID: mdl-36573396

RESUMEN

During navigation, information at multiple scales needs to be integrated. Single-unit recordings in rodents suggest that gradients of temporal dynamics in the hippocampus and entorhinal cortex support this integration. In humans, gradients of representation are observed, such that granularity of information represented increases along the long axis of the hippocampus. The neural underpinnings of this gradient in humans, however, are still unknown. Current research is limited by coarse fMRI analysis techniques that obscure the activity of individual voxels, preventing investigation of how moment-to-moment changes in brain signal are organized and how they are related to behavior. Here, we measured the signal stability of single voxels over time to uncover previously unappreciated gradients of temporal dynamics in the hippocampus and entorhinal cortex. Using our novel, single voxel autocorrelation technique, we show a medial-lateral hippocampal gradient, as well as a continuous autocorrelation gradient along the anterolateral-posteromedial entorhinal extent. Importantly, we show that autocorrelation in the anterior-medial hippocampus was modulated by navigational difficulty, providing the first evidence that changes in signal stability in single voxels are relevant for behavior. This work opens the door for future research on how temporal gradients within these structures support the integration of information for goal-directed behavior.


Asunto(s)
Corteza Entorrinal , Hipocampo , Humanos , Corteza Entorrinal/diagnóstico por imagen , Hipocampo/diagnóstico por imagen , Descanso , Imagen por Resonancia Magnética , Cabeza
8.
Memory ; 32(4): 431-448, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38557252

RESUMEN

Remembering life experiences involves recalling not only what occurred (episodic details), but also where an event took place (spatial context), both of which decline with age. Although spatial context can cue episodic detail recollection, it is unknown whether initially recalling an event alongside greater reinstatement of spatial context protects memory for episodic details in the long term, and whether this is affected by age. Here, we analysed 1079 personally-experienced, real-world events from 29 older adults and 12 younger adults. Events were recalled first on average 6 weeks after they occurred and then again on average 24 weeks after they occurred. We developed a novel scoring protocol to quantify spatial contextual details and used the established Autobiographical Interview to quantify episodic details. We found improved recall of episodic details after a delay if those details had initially been recalled situated in greater spatial context. Notably, for both older and younger adults, this preservation was observed for memories initially recalled with low, but not high, numbers of episodic details, suggesting that spatial context aided episodic retrieval for memories that required more support. This work supports the notion that spatial context scaffolds detail-rich event recollection and inspires memory interventions that leverage this spatial scaffold.


Asunto(s)
Memoria Episódica , Recuerdo Mental , Humanos , Masculino , Femenino , Adulto Joven , Anciano , Adulto , Envejecimiento/psicología , Persona de Mediana Edad , Factores de Edad , Señales (Psicología) , Adolescente
9.
Proc Natl Acad Sci U S A ; 118(51)2021 12 21.
Artículo en Inglés | MEDLINE | ID: mdl-34911768

RESUMEN

The brain supports adaptive behavior by generating predictions, learning from errors, and updating memories to incorporate new information. Prediction error, or surprise, triggers learning when reality contradicts expectations. Prior studies have shown that the hippocampus signals prediction errors, but the hypothesized link to memory updating has not been demonstrated. In a human functional MRI study, we elicited mnemonic prediction errors by interrupting familiar narrative videos immediately before the expected endings. We found that prediction errors reversed the relationship between univariate hippocampal activation and memory: greater hippocampal activation predicted memory preservation after expected endings, but memory updating after surprising endings. In contrast to previous studies, we show that univariate activation was insufficient for understanding hippocampal prediction error signals. We explain this surprising finding by tracking both the evolution of hippocampal activation patterns and the connectivity between the hippocampus and neuromodulatory regions. We found that hippocampal activation patterns stabilized as each narrative episode unfolded, suggesting sustained episodic representations. Prediction errors disrupted these sustained representations and the degree of disruption predicted memory updating. The relationship between hippocampal activation and subsequent memory depended on concurrent basal forebrain activation, supporting the idea that cholinergic modulation regulates attention and memory. We conclude that prediction errors create conditions that favor memory updating, prompting the hippocampus to abandon ongoing predictions and make memories malleable.


Asunto(s)
Hipocampo/fisiología , Memoria Episódica , Adolescente , Adulto , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Recuerdo Mental/fisiología , Persona de Mediana Edad , Red Nerviosa , Prosencéfalo/fisiología , Adulto Joven
10.
Hum Factors ; 66(5): 1520-1530, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-36657138

RESUMEN

OBJECTIVE: This study used a virtual environment to examine how older and younger pedestrians responded to simulated augmented reality (AR) overlays that indicated the crossability of gaps in a continuous stream of traffic. BACKGROUND: Older adults represent a vulnerable group of pedestrians. AR has the potential to make the task of street-crossing safer and easier for older adults. METHOD: We used an immersive virtual environment to conduct a study with age group and condition as between-subjects factors. In the control condition, older and younger participants crossed a continuous stream of traffic without simulated AR overlays. In the AR condition, older and younger participants crossed with simulated AR overlays signaling whether gaps between vehicles were safe or unsafe to cross. Participants were subsequently interviewed about their experience. RESULTS: We found that participants were more selective in their crossing decisions and took safer gaps in the AR condition as compared to the control condition. Older adult participants also reported reduced mental and physical demand in the AR condition compared to the control condition. CONCLUSION: AR overlays that display the crossability of gaps between vehicles have the potential to make street-crossing safer and easier for older adults. Additional research is needed in more complex real-world scenarios to further examine how AR overlays impact pedestrian behavior. APPLICATION: With rapid advances in autonomous vehicle and vehicle-to-pedestrian communication technologies, it is critical to study how pedestrians can be better supported. Our research provides key insights for ways to improve pedestrian safety applications using emerging technologies like AR.


Asunto(s)
Realidad Aumentada , Peatones , Humanos , Anciano , Accidentes de Tránsito/prevención & control , Caminata , Seguridad
11.
Arch Orthop Trauma Surg ; 144(5): 1917-1924, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38492065

RESUMEN

INTRODUCTION: Rib fractures commonly occur in trauma patients with varying presentations. Though the literature in recent years has moved toward favoring more early intervention of acute rib fractures, little has been reported on the matter of surgical fixation for symptomatic rib fracture nonunions. MATERIALS AND METHODS: We performed a review of PubMed and Cochrane databases for articles published since 2000. Inclusion criteria were studies with greater than six months of follow-up, while case studies were excluded. A thorough analysis was performed on patient outcomes, complications reported, operative techniques utilized, and fixation systems used, among other parameters reported by the articles. RESULTS: One hundred and thirty-nine studies resulted from our review, and a total of nine studies met our inclusion criteria with a combined total of 182 patients who underwent open reduction and internal fixation for symptomatic rib fracture nonunions. All studies reported a significant reduction of pain with increased satisfaction in the majority of patients. There were a total of 71 postoperative complications, the most common of which included surgical site infections, hardware failure, and hematoma. The most serious complications were insulting injury to the lung parenchyma or pleura; however, these were extremely rare based off the current literature. The use of bone grafting was common with eight of the nine studies mentioning the benefits of grafting. CONCLUSION: Surgical stabilization of rib fracture nonunions appears to be an appropriate treatment alternative, and various techniques and approaches may be used with similar success. Further studies with higher level of evidence are recommended on the subject.


Asunto(s)
Fijación Interna de Fracturas , Fracturas no Consolidadas , Fracturas de las Costillas , Humanos , Fracturas de las Costillas/cirugía , Fracturas no Consolidadas/cirugía , Fijación Interna de Fracturas/métodos , Complicaciones Posoperatorias/epidemiología , Trasplante Óseo/métodos
12.
J Cogn Neurosci ; 35(10): 1635-1655, 2023 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-37584584

RESUMEN

In March 2020, C.T., a kind, bright, and friendly young woman underwent surgery for a midline tumor involving her septum pellucidum and extending down into her fornices bilaterally. Following tumor diagnosis and surgery, C.T. experienced significant memory deficits: C.T.'s family reported that she could remember things throughout the day, but when she woke up in the morning or following a nap, she would expect to be in the hospital, forgetting all the information that she had learned before sleep. The current study aimed to empirically validate C.T.'s pattern of memory loss and explore its neurological underpinnings. On two successive days, C.T. and age-matched controls watched an episode of a TV show and took a nap or stayed awake before completing a memory test. Although C.T. performed numerically worse than controls in both conditions, sleep profoundly exacerbated her memory impairment, such that she could not recall any details following a nap. This effect was replicated in a second testing session. High-resolution MRI scans showed evidence of the trans-callosal surgical approach's impact on the mid-anterior corpus callosum, indicated that C.T. had perturbed white matter particularly in the right fornix column, and demonstrated that C.T.'s hippocampal volumes did not differ from controls. These findings suggest that the fornix is important for processing episodic memories during sleep. As a key output pathway of the hippocampus, the fornix may ensure that specific memories are replayed during sleep, maintain the balance of sleep stages, or allow for the retrieval of memories following sleep.


Asunto(s)
Recuerdo Mental , Sueño , Humanos , Femenino , Fórnix/diagnóstico por imagen , Aprendizaje , Hipocampo/diagnóstico por imagen , Trastornos de la Memoria/etiología
13.
J Cogn Neurosci ; 35(5): 869-884, 2023 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-36877081

RESUMEN

The ability to flexibly categorize object concepts is essential to semantic cognition because the features that make two objects similar in one context may be irrelevant and even constitute interference in another. Thus, adaptive behavior in complex and dynamic environments requires the resolution of feature-based interference. In the current case study, we placed visual and functional semantic features in opposition across object concepts in two categorization tasks. Successful performance required the resolution of functional interference in a visual categorization task and the resolution of visual interference in a functional categorization task. In Experiment 1, we found that patient D. A., an individual with bilateral temporal lobe lesions, was unable to categorize object concepts in a context-dependent manner. His impairment was characterized by an increased tendency to incorrectly group objects that were similar on the task-irrelevant dimension, revealing an inability to resolve cross-modal semantic interference. In Experiment 2, D. A.'s categorization accuracy was comparable to controls when lures were removed, indicating that his impairment is unique to contexts that involve cross-modal interference. In Experiment 3, he again performed as well as controls when categorizing simple concepts, suggesting that his impairment is specific to categorization of complex object concepts. These results advance our understanding of the anterior temporal lobe as a system that represents object concepts in a manner that enables flexible semantic cognition. Specifically, they reveal a dissociation between semantic representations that contribute to the resolution of cross-modal interference and those that contribute to the resolution of interference within a given modality.


Asunto(s)
Semántica , Lóbulo Temporal , Masculino , Humanos , Lóbulo Temporal/patología , Cognición , Imagen por Resonancia Magnética
14.
Am J Physiol Endocrinol Metab ; 325(1): E10-E20, 2023 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-37196059

RESUMEN

Metabolic dysfunction-associated fatty liver disease (MAFLD) represents a growing cause of mortality and morbidity and encompasses a spectrum of liver pathologies. Although dozens of preclinical models have been developed to recapitulate stages of MAFLD, few achieve fibrosis using an experimental design that mimics human pathogenesis. We sought to clarify whether the combination of thermoneutral (TN) housing and consumption of a classical Western diet (WD) would accelerate the onset and progression of MAFLD. Male and female C57Bl/6J mice were fed a nutrient-matched low-fat control or Western diet (WD) for 16 wk. Mice were housed with littermates at either standard temperature (TS; 22°C) or thermoneutral-like conditions (TN; ∼29°C). Male, but not female, mice housed at TN and fed a WD were significantly heavier than TS-housed control animals. WD-fed mice housed under TN conditions had lower levels of circulating glucose compared with TS mice; however, there were select but minimal differences in other circulating markers. Although WD-fed TN males had higher liver enzyme and higher liver triglyceride levels, no differences in markers of liver injury or hepatic lipid accumulation were observed in females. Housing temperature had little effect on histopathological scoring of MAFLD progression in males; however, although female mice retained a level of protection, WD-TN conditions trended toward a worsened hepatic phenotype, which was associated with higher macrophage transcript expression and content. Our results indicate that interventions coupling TN housing and WD-induced MAFLD should be longer than 16 wk to accelerate hepatic steatosis and increase inflammation in both sexes of mice.NEW & NOTEWORTHY Mouse models leading to accelerated fatty liver onset are a useful translational tool. Here we show that coupling thermoneutral-like housing and Western diet feeding in mice for 16 wk does not lead to significant disease progression in either sex, though the molecular phenotype indicates priming of immune-related and fibrotic pathways.


Asunto(s)
Vivienda , Enfermedad del Hígado Graso no Alcohólico , Humanos , Femenino , Masculino , Animales , Ratones , Ratones Endogámicos C57BL , Dieta Occidental/efectos adversos , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Hígado/metabolismo , Fibrosis
15.
PLoS Pathog ; 17(1): e1009275, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33513206

RESUMEN

Filoviruses, such as the Ebola virus (EBOV) and Marburg virus (MARV), are causative agents of sporadic outbreaks of hemorrhagic fevers in humans. To infect cells, filoviruses are internalized via macropinocytosis and traffic through the endosomal pathway where host cathepsin-dependent cleavage of the viral glycoproteins occurs. Subsequently, the cleaved viral glycoprotein interacts with the late endosome/lysosome resident host protein, Niemann-Pick C1 (NPC1). This interaction is hypothesized to trigger viral and host membrane fusion, which results in the delivery of the viral genome into the cytoplasm and subsequent initiation of replication. Some studies suggest that EBOV viral particles activate signaling cascades and host-trafficking factors to promote their localization with host factors that are essential for entry. However, the mechanism through which these activating signals are initiated remains unknown. By screening a kinase inhibitor library, we found that receptor tyrosine kinase inhibitors potently block EBOV and MARV GP-dependent viral entry. Inhibitors of epidermal growth factor receptor (EGFR), tyrosine protein kinase Met (c-Met), and the insulin receptor (InsR)/insulin like growth factor 1 receptor (IGF1R) blocked filoviral GP-mediated entry and prevented growth of replicative EBOV in Vero cells. Furthermore, inhibitors of c-Met and InsR/IGF1R also blocked viral entry in macrophages, the primary targets of EBOV infection. Interestingly, while the c-Met and InsR/IGF1R inhibitors interfered with EBOV trafficking to NPC1, virus delivery to the receptor was not impaired in the presence of the EGFR inhibitor. Instead, we observed that the NPC1 positive compartments were phenotypically altered and rendered incompetent to permit viral entry. Despite their different mechanisms of action, all three RTK inhibitors tested inhibited virus-induced Akt activation, providing a possible explanation for how EBOV may activate signaling pathways during entry. In sum, these studies strongly suggest that receptor tyrosine kinases initiate signaling cascades essential for efficient post-internalization entry steps.


Asunto(s)
Ebolavirus/fisiología , Fiebre Hemorrágica Ebola/virología , Proteínas Tirosina Quinasas/metabolismo , Transducción de Señal , Animales , Chlorocebus aethiops , Ebolavirus/genética , Endocitosis , Endosomas/metabolismo , Endosomas/virología , Interacciones Huésped-Patógeno , Humanos , Espacio Intracelular/virología , Lisosomas/metabolismo , Transporte de Proteínas , Proteínas Tirosina Quinasas/genética , Células Vero , Virión , Internalización del Virus , Replicación Viral
16.
J Anat ; 243(3): 448-466, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37190673

RESUMEN

Tree sloths evolved below-branch locomotion making them one of few mammalian taxa beyond primates for which suspension is nearly obligatory. Suspension requires strong limb flexor muscles that provide both propulsion and braking/support, and available locomotor kinetics data indicate that these roles differ between fore- and hindlimb pairs. Muscle structure in the pelvic limb is hypothesized to be a key anatomical correlate of function in braking/support during suspensory walking and propulsion and/or support during vertical climbing. This expectation was tested by quantifying architecture properties in the hindlimb limb musculature of brown-throated three-toed sloths (Bradypus variegatus: N = 7) to distinguish the roles of the flexor/extensor functional muscle groups at each joint. Measurements of muscle moment arm (rm ), mass, belly length, fascicle length, pennation angle, and physiological cross-sectional area (PCSA) were taken from n = 45 muscles. Overall, most muscles studied show properties for contractile excursion and fast joint rotational velocity. However, the flexor musculature is more massive (p = 0.048) and has larger PCSA (p = 0.003) than the extensors, especially at the knee joint and digits where well-developed and strong flexors are capable of applying large joint torque. Moreover, selected hip flexors/extensors and knee flexors have modified long rm that can amplify applied joint torque in muscles with otherwise long, parallel fascicles, and one muscle (m. iliopsoas) was capable of moderately high power in B. variegatus. The architectural properties observed in the hip flexors and extensors match well with roles in suspensory braking and vertical propulsion, respectively, whereas strong knee flexors and digital flexors appear to be the main muscles providing suspensory support in the pelvic limb. With aid in support by the forelimbs and the use of adaptive slow locomotion and slow muscle fiber recruitment patterns, structure-function in the tensile limb systems of sloths appears to collectively represent an additional mechanism for energy conservation.


Asunto(s)
Perezosos , Animales , Perezosos/fisiología , Músculo Esquelético/fisiología , Fibras Musculares Esqueléticas , Contracción Muscular/fisiología , Miembro Posterior/fisiología
17.
Anesthesiology ; 139(5): 667-674, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37582252

RESUMEN

BACKGROUND: Healthcare trainees frequently report facing comments from their patients pertaining to their age. Exposure to ageist comments from patients may be related to greater stress and/or burnout in residents and may impact the quality of the resident-patient relationship. However, little empirical work has examined ageism expressed toward anesthesiology residents in clinical care, and therefore not much is known about how residents respond to these comments in practice. This research sought to determine how anesthesiology residents responded to ageist comments. METHODS: Anesthesiology residents (N = 60) engaged in a preoperative interaction with a standardized patient who was instructed to make an ageist comment to the resident. Resident responses were transcribed and coded using qualitative inductive content analysis to identify response themes. RESULTS: The most common resident response to the ageist comment, across gender and resident year, was to state their own experience. Some also described how they were still in training or that they were under supervision. Residents rarely reassured the patient that they would receive good care or identified the patient's anxiety as a cause of the ageist remark. CONCLUSIONS: These results provide a first step in understanding how ageism may be navigated by residents in clinical encounters. The authors discuss potential avenues for future research and education for responding to ageist remarks for both patients and clinicians.

18.
Nutr Neurosci ; 26(10): 953-959, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36039916

RESUMEN

BACKGROUND: Recent explorations into the gut microbiome of humans and animals reveal implications in chronic physical and mental health disorders. Relatively little is known regarding the relationship of gut microbiome and depression. In the current review, we reviewed existing scientific data related to the gut microbiome and healthy patients versus patients with depression. Additionally, scientific literature containing the utility of microbiome interventions to improve depression symptoms was reviewed. METHODS: A PubMed and Clinical Key literature search combined the key terms 'gut,' 'microbiome,' 'bacteria,' and 'depression' to identify studies investigating these relationships. RESULTS: 76 relevant articles were identified. Human and animal studies reviewed examined marked alterations in the dominant bacterial phyla in the gut of individuals with depression, the connection between leaky gut and neuroinflammation in depression, brain regulatory centers impacted by changes in the gut microbiome, and the benefits of the addition of a probiotic/prebiotic for gut and mental health. CONCLUSIONS: The current review confirmed the suspected direct communication between the gut microbiome, brain functioning, and depression. Additionally, studies suggest antibiotics disrupt the gut microbiome. There are important implications for psychiatrists in providing opportunities for intervention and enhancement of current treatments for individuals with depression.


Asunto(s)
Microbioma Gastrointestinal , Trastornos Mentales , Probióticos , Animales , Humanos , Encéfalo , Salud Mental , Probióticos/uso terapéutico
19.
Acta Obstet Gynecol Scand ; 102(11): 1440-1449, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37417714

RESUMEN

INTRODUCTION: Evidence comparing double-balloon vs single-balloon catheter for induction of labor is divided. We aim to compare the efficacy and safety of double-vs single-balloon catheters using individual participant data. MATERIAL AND METHODS: A search of Ovid MEDLINE, Embase, Ovid Emcare, CINAHL Plus, Scopus, and clinicaltrials.gov was conducted for randomized controlled trials published from March 2019 until April 13, 2021. Earlier trials were identified from the Cochrane Review on Mechanical Methods for Induction of Labour. Randomized controlled trials that compared double-balloon with single-balloon catheters for induction of labor in singleton gestations were eligible. Participant-level data were sought from trial investigators and an individual participant data meta-analysis was performed. The primary outcomes were rates of vaginal birth achieved, a composite measure of adverse maternal outcomes and a composite measure of adverse perinatal outcomes. We used a two-stage random-effects model. Data were analyzed from the intention-to-treat perspective. RESULTS: Of the eight eligible randomized controlled trials, three shared individual-level data with a total of 689 participants, 344 women in the double-balloon catheter group and 345 women in the single-balloon catheter group. The difference in the rate of vaginal birth between double-balloon catheter and single-balloon catheter was not statistically significant (relative risk [RR] 0.93, 95% confidence interval [CI] 0.86-1.00, p = 0.050; I2 0%; moderate-certainty evidence). Both perinatal outcomes (RR 0.81, 95% CI 0.54-1.21, p = 0.691; I2 0%; moderate-certainty evidence) and maternal composite outcomes (RR 0.65, 95% CI 0.15-2.87, p = 0.571; I2 55.46%; low-certainty evidence) were not significantly different between the two groups. CONCLUSIONS: Single-balloon catheter is at least comparable to double-balloon catheter in terms of vaginal birth rate and maternal and perinatal safety outcomes.


Asunto(s)
Maduración Cervical , Trabajo de Parto Inducido , Embarazo , Humanos , Femenino , Trabajo de Parto Inducido/métodos , Riesgo , Catéteres
20.
Appl Opt ; 62(6): A12-A24, 2023 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-36821295

RESUMEN

The design, validation, and application of a quantum-cascade-laser-absorption-spectroscopy diagnostic for measuring gas temperature, pressure, and nitric oxide (NO) in high-temperature air are presented. A distributed-feedback quantum-cascade laser (QCL) centered near 1976c m -1 was used to scan across two transitions of NO in its ground electronic state (X 2 Π 1/2). A measurement rate of 500 kHz was achieved using a single QCL by: (1) performing current modulation through a bias-tee, and (2) targeting closely spaced transitions with a large difference in lower-state energy. The diagnostic was validated in a mixture of 95% argon and 5% NO, which was shock-heated to ≈2000 to 3700 K. The average mean percent differences between laser-absorption-spectroscopy (LAS) measurements and predictions from shock-jump relations for temperature, pressure, and NO mole fraction were 3.1%, 4.1%, and 6.5%, respectively. The diagnostic was then applied to characterize shock-heated air at high temperatures (up to ≈5500K) and high pressures (up to 12 atm) behind either incident or reflected shocks. The LAS measurements were compared to theoretical predictions from shock-jump relations, pressure sensors mounted in the wall of the shock tube, and equilibrium values of the NO mole fraction. The average mean percent differences between LAS measurements and their aforementioned reference values were 3.2%, 10.8%, and 10.4% for temperature, pressure, and NO mole fraction, respectively. Last, a comparison between a measured NO mole fraction time history and a time-stepped homogeneous reactor simulation performed using two different chemical kinetics mechanisms is presented.

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