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2.
Nature ; 614(7946): 102-107, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36697827

RESUMEN

Living amphibians (Lissamphibia) include frogs and salamanders (Batrachia) and the limbless worm-like caecilians (Gymnophiona). The estimated Palaeozoic era gymnophionan-batrachian molecular divergence1 suggests a major gap in the record of crown lissamphibians prior to their earliest fossil occurrences in the Triassic period2-6. Recent studies find a monophyletic Batrachia within dissorophoid temnospondyls7-10, but the absence of pre-Jurassic period caecilian fossils11,12 has made their relationships to batrachians and affinities to Palaeozoic tetrapods controversial1,8,13,14. Here we report the geologically oldest stem caecilian-a crown lissamphibian from the Late Triassic epoch of Arizona, USA-extending the caecilian record by around 35 million years. These fossils illuminate the tempo and mode of early caecilian morphological and functional evolution, demonstrating a delayed acquisition of musculoskeletal features associated with fossoriality in living caecilians, including the dual jaw closure mechanism15,16, reduced orbits17 and the tentacular organ18. The provenance of these fossils suggests a Pangaean equatorial origin for caecilians, implying that living caecilian biogeography reflects conserved aspects of caecilian function and physiology19, in combination with vicariance patterns driven by plate tectonics20. These fossils reveal a combination of features that is unique to caecilians alongside features that are shared with batrachian and dissorophoid temnospondyls, providing new and compelling evidence supporting a single origin of living amphibians within dissorophoid temnospondyls.


Asunto(s)
Anfibios , Anuros , Fósiles , Filogenia , Urodelos , Animales , Anfibios/anatomía & histología , Anuros/anatomía & histología , Arizona , Urodelos/anatomía & histología , Órbita/anatomía & histología , Maxilares/anatomía & histología , Sistema Musculoesquelético/anatomía & histología
3.
PLoS Biol ; 21(8): e3002239, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37651504

RESUMEN

Understanding central auditory processing critically depends on defining underlying auditory cortical networks and their relationship to the rest of the brain. We addressed these questions using resting state functional connectivity derived from human intracranial electroencephalography. Mapping recording sites into a low-dimensional space where proximity represents functional similarity revealed a hierarchical organization. At a fine scale, a group of auditory cortical regions excluded several higher-order auditory areas and segregated maximally from the prefrontal cortex. On mesoscale, the proximity of limbic structures to the auditory cortex suggested a limbic stream that parallels the classically described ventral and dorsal auditory processing streams. Identities of global hubs in anterior temporal and cingulate cortex depended on frequency band, consistent with diverse roles in semantic and cognitive processing. On a macroscale, observed hemispheric asymmetries were not specific for speech and language networks. This approach can be applied to multivariate brain data with respect to development, behavior, and disorders.


Asunto(s)
Corteza Auditiva , Humanos , Percepción Auditiva , Encéfalo , Electrocorticografía , Electrofisiología
4.
J Neurosci ; 44(33)2024 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-38937102

RESUMEN

The neocortex and striatum are topographically organized for sensory and motor functions. While sensory and motor areas are lateralized for touch and motor control, respectively, frontal areas are involved in decision-making, where lateralization of function may be less important. This study contrasted the topographic precision of cell-type-specific ipsilateral and contralateral cortical projections while varying the injection site location in transgenic mice of both sexes. While sensory cortical areas had strongly topographic outputs to the ipsilateral cortex and striatum, they were weaker and not as topographically precise to contralateral targets. The motor cortex had somewhat stronger projections but still relatively weak contralateral topography. In contrast, frontal cortical areas had high degrees of topographic similarity for both ipsilateral and contralateral projections to the cortex and striatum. Corticothalamic organization is mainly ipsilateral, with weaker, more medial contralateral projections. Corticostriatal computations might integrate input outside closed basal ganglia loops using contralateral projections, enabling the two hemispheres to act as a unit to converge on one result in motor planning and decision-making.


Asunto(s)
Lóbulo Frontal , Ratones Transgénicos , Corteza Motora , Vías Nerviosas , Corteza Somatosensorial , Animales , Corteza Motora/fisiología , Masculino , Femenino , Ratones , Corteza Somatosensorial/fisiología , Lóbulo Frontal/fisiología , Vías Nerviosas/fisiología , Lateralidad Funcional/fisiología , Cuerpo Estriado/fisiología
5.
Nature ; 575(7783): 464-467, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31748724

RESUMEN

Gamma-ray bursts (GRBs) are brief flashes of γ-rays and are considered to be the most energetic explosive phenomena in the Universe1. The emission from GRBs comprises a short (typically tens of seconds) and bright prompt emission, followed by a much longer afterglow phase. During the afterglow phase, the shocked outflow-produced by the interaction between the ejected matter and the circumburst medium-slows down, and a gradual decrease in brightness is observed2. GRBs typically emit most of their energy via γ-rays with energies in the kiloelectronvolt-to-megaelectronvolt range, but a few photons with energies of tens of gigaelectronvolts have been detected by space-based instruments3. However, the origins of such high-energy (above one gigaelectronvolt) photons and the presence of very-high-energy (more than 100 gigaelectronvolts) emission have remained elusive4. Here we report observations of very-high-energy emission in the bright GRB 180720B deep in the GRB afterglow-ten hours after the end of the prompt emission phase, when the X-ray flux had already decayed by four orders of magnitude. Two possible explanations exist for the observed radiation: inverse Compton emission and synchrotron emission of ultrarelativistic electrons. Our observations show that the energy fluxes in the X-ray and γ-ray range and their photon indices remain comparable to each other throughout the afterglow. This discovery places distinct constraints on the GRB environment for both emission mechanisms, with the inverse Compton explanation alleviating the particle energy requirements for the emission observed at late times. The late timing of this detection has consequences for the future observations of GRBs at the highest energies.

6.
J Biol Chem ; 299(7): 104834, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37201585

RESUMEN

Chromatin organization is highly dynamic and modulates DNA replication, transcription, and chromosome segregation. Condensin is essential for chromosome assembly during mitosis and meiosis, as well as maintenance of chromosome structure during interphase. While it is well established that sustained condensin expression is necessary to ensure chromosome stability, the mechanisms that control its expression are not yet known. Herein, we report that disruption of cyclin-dependent kinase 7 (CDK7), the core catalytic subunit of CDK-activating kinase, leads to reduced transcription of several condensin subunits, including structural maintenance of chromosomes 2 (SMC2). Live and static microscopy revealed that inhibiting CDK7 signaling prolongs mitosis and induces chromatin bridge formation, DNA double-strand breaks, and abnormal nuclear features, all of which are indicative of mitotic catastrophe and chromosome instability. Affirming the importance of condensin regulation by CDK7, genetic suppression of the expression of SMC2, a core subunit of this complex, phenocopies CDK7 inhibition. Moreover, analysis of genome-wide chromatin conformation using Hi-C revealed that sustained activity of CDK7 is necessary to maintain chromatin sublooping, a function that is ascribed to condensin. Notably, the regulation of condensin subunit gene expression is independent of superenhancers. Together, these studies reveal a new role for CDK7 in sustaining chromatin configuration by ensuring the expression of condensin genes, including SMC2.


Asunto(s)
Cromatina , Quinasas Ciclina-Dependientes , Transducción de Señal , Cromatina/genética , Cromatina/metabolismo , Quinasas Ciclina-Dependientes/genética , Quinasas Ciclina-Dependientes/metabolismo , Mitosis/genética , Inestabilidad Cromosómica/genética , Humanos , Línea Celular Tumoral , Regulación de la Expresión Génica/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Silenciador del Gen
7.
J Am Chem Soc ; 146(22): 15019-15026, 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38743719

RESUMEN

Electrocatalytic water oxidation is a key transformation in many strategies designed to harness solar energy and store it as chemical fuels. Understanding the mechanism(s) of the best electrocatalysts for water oxidation has been a fundamental chemical challenge for decades. Here, we quantitate evolved dioxygen isotopologue composition via gas-phase EPR spectroscopy to elucidate the mechanisms of water oxidation on metal oxide electrocatalysts with high precision. Isotope fractionation is paired with computational and kinetic modeling, showing that this technique is sensitive enough to differentiate O-O bond-forming steps. Strong agreement between experiment and theory indicates that for the nickel-iron layered double hydroxide─one of the best earth-abundant electrocatalysts to be studied─water oxidation proceeds via a dioxo coupling mechanism to form a side-bound peroxide rather than a hydroxide attack to form an end-bound peroxide.

8.
N Engl J Med ; 385(11): 971-981, 2021 09 09.
Artículo en Inglés | MEDLINE | ID: mdl-34496173

RESUMEN

BACKGROUND: Mobile stroke units (MSUs) are ambulances with staff and a computed tomographic scanner that may enable faster treatment with tissue plasminogen activator (t-PA) than standard management by emergency medical services (EMS). Whether and how much MSUs alter outcomes has not been extensively studied. METHODS: In an observational, prospective, multicenter, alternating-week trial, we assessed outcomes from MSU or EMS management within 4.5 hours after onset of acute stroke symptoms. The primary outcome was the score on the utility-weighted modified Rankin scale (range, 0 to 1, with higher scores indicating better outcomes according to a patient value system, derived from scores on the modified Rankin scale of 0 to 6, with higher scores indicating more disability). The main analysis involved dichotomized scores on the utility-weighted modified Rankin scale (≥0.91 or <0.91, approximating scores on the modified Rankin scale of ≤1 or >1) at 90 days in patients eligible for t-PA. Analyses were also performed in all enrolled patients. RESULTS: We enrolled 1515 patients, of whom 1047 were eligible to receive t-PA; 617 received care by MSU and 430 by EMS. The median time from onset of stroke to administration of t-PA was 72 minutes in the MSU group and 108 minutes in the EMS group. Of patients eligible for t-PA, 97.1% in the MSU group received t-PA, as compared with 79.5% in the EMS group. The mean score on the utility-weighted modified Rankin scale at 90 days in patients eligible for t-PA was 0.72 in the MSU group and 0.66 in the EMS group (adjusted odds ratio for a score of ≥0.91, 2.43; 95% confidence interval [CI], 1.75 to 3.36; P<0.001). Among the patients eligible for t-PA, 55.0% in the MSU group and 44.4% in the EMS group had a score of 0 or 1 on the modified Rankin scale at 90 days. Among all enrolled patients, the mean score on the utility-weighted modified Rankin scale at discharge was 0.57 in the MSU group and 0.51 in the EMS group (adjusted odds ratio for a score of ≥0.91, 1.82; 95% CI, 1.39 to 2.37; P<0.001). Secondary clinical outcomes generally favored MSUs. Mortality at 90 days was 8.9% in the MSU group and 11.9% in the EMS group. CONCLUSIONS: In patients with acute stroke who were eligible for t-PA, utility-weighted disability outcomes at 90 days were better with MSUs than with EMS. (Funded by the Patient-Centered Outcomes Research Institute; BEST-MSU ClinicalTrials.gov number, NCT02190500.).


Asunto(s)
Ambulancias , Servicios Médicos de Urgencia , Accidente Cerebrovascular Isquémico/tratamiento farmacológico , Unidades Móviles de Salud , Tiempo de Tratamiento , Activador de Tejido Plasminógeno/uso terapéutico , Anciano , Evaluación de la Discapacidad , Femenino , Humanos , Accidente Cerebrovascular Isquémico/complicaciones , Accidente Cerebrovascular Isquémico/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Índice de Severidad de la Enfermedad , Tomografía Computarizada por Rayos X
9.
Artículo en Inglés | MEDLINE | ID: mdl-39269453

RESUMEN

Lymphatic vessels of the heart undergo dynamic remodeling in response to physiological and pathological cardiovascular events such as development, adult cardiac maintenance and injury repair. During pregnancy, the cardiovascular system undergoes physiological changes to meet the increased demand of blood supply to the fetus. These extensive physiologic changes make pregnancy and delivery a high-risk period in a woman's life. However, whether and how cardiac lymphatics change during pregnancy is largely undefined. Therefore, we used whole mount immunofluorescent labeling and quantitative morphometric analysis to characterize the changes in cardiac lymphatic vasculature during pregnancy using two genetically distinct inbred mouse strains, C57BL/6J and BALB/cJ. Compared to age-matched, non-pregnant C57BL/6J control mice, the hearts of C57BL/6J dams in late-pregnancy (gestation day 17.5 (G17.5)) undergo physiologic hypertrophy. However, there were no significant changes in the cardiac lymphatic vasculature. In contrast, BALB/cJ mice do not exhibit pregnancy-induced cardiac hypertrophy at G17.5 compared to age-matched, non-pregnant mice. Yet interestingly, the cardiac lymphatic vasculature of pregnant BALB/cJ dams undergoes extensive morphological changes, including decreased lymphatic length, number of endpoints, and vessel branchpoint junctions on the ventral side of the heart. These findings underscore the complexity of genetic and physiologic factors that contribute to the heterotypic remodeling of cardiac lymphatics during late pregnancy.

10.
J Pediatr ; 265: 113816, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37931699

RESUMEN

OBJECTIVES: To assess postmortem vitamin A (VA) concentrations in children under 5 years of age and evaluate the association between VA deficiency (VAD) and infectious causes of death (CoD). STUDY DESIGN: In this cross-sectional study from the Child Health and Mortality Prevention Surveillance (CHAMPS) Network, liver biopsies collected within 72 hours of death were analyzed from 405 stillbirths and children under 5 years in Kenya and South Africa. Total liver VA (TLVA) concentrations were quantified using ultra-performance liquid chromatography, and cutoffs of ≤0.1 µmol/g, >0.1 to <0.7 µmol/g, ≥0.7 to <1.0 µmol/g, and ≥1.0 µmol/g were used to define VAD, adequate VA status, high VA, and hypervitaminosis A, respectively. CoD were determined by expert panel review. RESULTS: Among 366 liver samples with viable extraction, pooled prevalences of VAD, adequacy, high VA, and hypervitaminosis were 34.2%, 51.1%, 6.0%, and 8.7%, respectively. VAD was more common among neonates compared with stillbirths, infants, or children, and among those with low birthweight (LBW), underweight, or stunting (P < .05). When adjusting for site, age, and sex, there was no significant association of VAD with increased infectious CoD (OR 1.9, 95% confidence interval [CI] 0.9, 3.8, P = .073). In stratified analyses, VA deficient boys, but not girls, had an increased risk of infectious CoD (OR 3.4, 95% CI 1.3, 10.3, P = .013). CONCLUSIONS: Definitive postmortem assessment of VA status identified both VAD and VA excess among children under 5 years of age in Kenya and South Africa. VAD in boys was associated with increased risk of infectious mortality. Our findings may inform a transition from universal VA supplementation (VAS) to targeted strategies in certain countries.


Asunto(s)
Enfermedades Transmisibles , Deficiencia de Vitamina A , Niño , Masculino , Lactante , Recién Nacido , Femenino , Embarazo , Humanos , Preescolar , Vitamina A/efectos adversos , Estudios Transversales , Mortinato , Deficiencia de Vitamina A/complicaciones , Deficiencia de Vitamina A/epidemiología , Vitaminas , Hígado
11.
Ann Surg Oncol ; 31(5): 3017-3023, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38347330

RESUMEN

INTRODUCTION: To improve the detection and management of perioperative hyperglycemia at our tertiary cancer center, we implemented a glycemic control quality improvement initiative. The primary goal was to decrease the percentage of diabetic patients with median postoperative glucose levels > 180 mg/dL during hospitalization by 15% within 2 years. METHODS: A multidisciplinary team standardized preoperative screening, preoperative, intraoperative, and postoperative hyperglycemia management. We included all patients undergoing nonemergent inpatient and outpatient operations. We used a t test, rank sum, chi-square, or Fisher's exact test to assess differences in outcomes between patients at baseline (BL) (10/2018-4/2019), during the first phase (P1) (10/2019-4/2020), second phase (P2) (5/2020-12/2020), and maintenance phase (M) (1/2021-10/2022). RESULTS: The analysis included 9891 BL surgical patients (1470 with diabetes), 8815 P1 patients (1233 with diabetes), 10,401 P2 patients (1531 with diabetes) and 30,410 M patients (4265 with diabetes). The percentage of diabetic patients with median glucose levels >180 mg/dL during hospitalization decreased 32% during the initiative (BL, 20.1%; P1, 16.9%; P2, 12.1%; M, 13.7% [P < .001]). We also saw reductions in the percentages of diabetic patients with median glucose levels >180 mg/dL intraoperatively (BL, 34.0%; P1, 26.6%; P2, 23.9%; M, 20.3% [P < .001]) and in the postanesthesia care unit (BL, 36.0%; P1, 30.4%; P2, 28.5%; M, 25.8% [P < .001]). The percentage of patients screened for diabetes by hemoglobin A1C increased during the initiative (BL, 17.5%; P1, 52.5%; P2, 66.8%; M 74.5% [P < .001]). CONCLUSIONS: Our successful initiative can be replicated in other hospitals to standardize and improve glycemic control among diabetic surgical patients.


Asunto(s)
Diabetes Mellitus , Hiperglucemia , Neoplasias , Humanos , Glucemia , Hiperglucemia/diagnóstico , Hiperglucemia/etiología , Diabetes Mellitus/diagnóstico , Hemoglobina Glucada , Atención Perioperativa , Estudios Retrospectivos
12.
Gynecol Oncol ; 191: 143-149, 2024 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-39396406

RESUMEN

OBJECTIVE: To evaluate the disease course of patients with low grade endometrial stromal sarcoma (LG-ESS) and compare oncologic outcomes associated with hormonal therapy in primary and recurrent disease. METHODS: This is a retrospective study of patients with LG-ESS who underwent active treatment between January 2000 and July 2023. Recurrence-free survival (RFS) and overall survival (OS) were estimated using the Kaplan-Meier product-limit estimator and modeled via Cox proportional hazards regression. RESULTS: A total of 221 patients were included; 58 % of patients (91/157) were stage I, 12 % (19/157) stage II, 13 % (20/157) stage III, and 17 % (27/157) stage IV. Surgery was the primary treatment for 98 % (213/218). Only 79 patients received hormonal adjuvant therapy, 58 % (46/79) Megace, 24 % (19/79) Letrozole, and 18 % (14/79) received other hormonal therapy. There was no significant difference in RFS (p = 0.159) and OS (p = 0.167) between patients receiving Megace versus Letrozole as adjuvant therapy. At first recurrence, patients given Megace had a similar RFS to those on Letrozole (p = 0.302), but a better OS (27 vs 10 months, p = 0.018).  Negative status of estrogen, smooth muscle actin, and desmin were associated with lower RFS (p = 0.039, p = 0.002, and p = 0.015, respectively) and OS (p = 0.008, p = 0.012, and p = 0.013, respectively). Lymphovascular invasion was associated with lower RFS (p = 0.033), and negative status of progesterone was associated with lower OS (p = 0.003). CONCLUSION: There was no difference in oncologic outcomes between Megace and Letrozole in patients who received adjuvant therapy for LG-ESS. Megace may have potential survival advantage in recurrent disease. Further study is warranted to determine the most effective agents and their sequence in the treatment of LG-ESS.

13.
J Neurooncol ; 166(1): 129-142, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38224404

RESUMEN

BACKGROUND: Malignant glioma carries a poor prognosis despite current therapeutic modalities. Standard of care therapy consists of surgical resection, fractionated radiotherapy concurrently administered with temozolomide (TMZ), a DNA-alkylating chemotherapeutic agent, followed by adjuvant TMZ. O-6-methylguanine-DNA methyltransferase (MGMT), a DNA repair enzyme, removes alkylated lesions from tumor DNA, thereby promoting chemoresistance. MGMT promoter methylation status predicts responsiveness to TMZ; patients harboring unmethylated MGMT (~60% of glioblastoma) have a poorer prognosis with limited treatment benefits from TMZ. METHODS: Via lentiviral-mediated delivery into LN18 glioma cells, we employed deactivated Cas9-CRISPR technology to target the MGMT promoter and enhancer regions for methylation, as mediated by the catalytic domain of the methylation enzyme DNMT3A. Methylation patterns were examined at a clonal level in regions containing Differentially Methylation Regions (DMR1, DMR2) and the Methylation Specific PCR (MSP) region used for clinical assessment of MGMT methylation status. Correlative studies of genomic and transcriptomic effects of dCas9/CRISPR-based methylation were performed via Illumina 850K methylation array platform and bulk RNA-Seq analysis. RESULTS: We used the dCas9/DNMT3A catalytic domain to achieve targeted MGMT methylation at specific CpG clusters in the vicinity of promoter, enhancer, DMRs and MSP regions. Consequently, we observed MGMT downregulation and enhanced glioma chemosensitivity in survival assays in vitro, with minimal off-target effects. CONCLUSION: dCas9/CRISPR is a viable method of epigenetic editing, using the DNMT3A catalytic domain. This study provides initial proof-of-principle for CRISPR technology applications in malignant glioma, laying groundwork for subsequent translational studies, with implications for future epigenetic editing-based clinical applications.


Asunto(s)
Neoplasias Encefálicas , Glioma , Guanina , Humanos , Antineoplásicos Alquilantes/farmacología , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/cirugía , Dacarbazina/farmacología , ADN/genética , ADN/metabolismo , Metilación de ADN , Metilasas de Modificación del ADN/genética , Enzimas Reparadoras del ADN/genética , Glioma/tratamiento farmacológico , Glioma/genética , Glioma/patología , Guanina/análogos & derivados , O(6)-Metilguanina-ADN Metiltransferasa/genética , Temozolomida/farmacología
14.
Acta Psychiatr Scand ; 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38890010

RESUMEN

BACKGROUND: Affective states influence the sympathetic nervous system, inducing variations in electrodermal activity (EDA), however, EDA association with bipolar disorder (BD) remains uncertain in real-world settings due to confounders like physical activity and temperature. We analysed EDA separately during sleep and wakefulness due to varying confounders and potential differences in mood state discrimination capacities. METHODS: We monitored EDA from 102 participants with BD including 35 manic, 29 depressive, 38 euthymic patients, and 38 healthy controls (HC), for 48 h. Fifteen EDA features were inferred by mixed-effect models for repeated measures considering sleep state, group and covariates. RESULTS: Thirteen EDA feature models were significantly influenced by sleep state, notably including phasic peaks (p < 0.001). During wakefulness, phasic peaks showed different values for mania (M [SD] = 6.49 [5.74, 7.23]), euthymia (5.89 [4.83, 6.94]), HC (3.04 [1.65, 4.42]), and depression (3.00 [2.07, 3.92]). Four phasic features during wakefulness better discriminated between HC and mania or euthymia, and between depression and euthymia or mania, compared to sleep. Mixed symptoms, average skin temperature, and anticholinergic medication affected the models, while sex and age did not. CONCLUSION: EDA measured from awake recordings better distinguished between BD states than sleep recordings, when controlled by confounders.

15.
J Chem Inf Model ; 64(13): 5262-5272, 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38869471

RESUMEN

Venezuelan equine encephalitis virus (VEEV) is a highly virulent pathogen whose nuclear localization signal (NLS) sequence from capsid protein binds to the host importin-α transport protein and blocks nuclear import. We studied the molecular mechanisms by which two small ligands, termed I1 and I2, interfere with the binding of VEEV's NLS peptide to importin-α protein. To this end, we performed all-atom replica exchange molecular dynamics simulations probing the competitive binding of the VEEV coreNLS peptide and I1 or I2 ligand to the importin-α major NLS binding site. As a reference, we used our previous simulations, which examined noncompetitive binding of the coreNLS peptide or the inhibitors to importin-α. We found that both inhibitors completely abrogate the native binding of the coreNLS peptide, forcing it to adopt a manifold of nonnative loosely bound poses within the importin-α major NLS binding site. Both inhibitors primarily destabilize the native coreNLS binding by masking its amino acids rather than competing with it for binding to importin-α. Because I2, in contrast to I1, binds off-site localizing on the edge of the major NLS binding site, it inhibits fewer coreNLS native binding interactions than I1. Structural analysis is supported by computations of the free energies of the coreNLS peptide binding to importin-α with or without competition from the inhibitors. Specifically, both inhibitors reduce the free energy gain from coreNLS binding, with I1 causing significantly larger loss than I2. To test our simulations, we performed AlphaScreen experiments measuring IC50 values for both inhibitors. Consistent with in silico results, the IC50 value for I1 was found to be lower than that for I2. We hypothesize that the inhibitory action of I1 and I2 ligands might be specific to the NLS from VEEV's capsid protein.


Asunto(s)
Unión Competitiva , Simulación de Dinámica Molecular , Señales de Localización Nuclear , alfa Carioferinas , alfa Carioferinas/metabolismo , alfa Carioferinas/química , alfa Carioferinas/antagonistas & inhibidores , Ligandos , Señales de Localización Nuclear/química , Virus de la Encefalitis Equina Venezolana/metabolismo , Virus de la Encefalitis Equina Venezolana/química , Unión Proteica , Péptidos/química , Péptidos/metabolismo , Péptidos/farmacología , Secuencia de Aminoácidos
16.
Cereb Cortex ; 33(17): 9850-9866, 2023 08 23.
Artículo en Inglés | MEDLINE | ID: mdl-37434363

RESUMEN

Theories of consciousness suggest that brain mechanisms underlying transitions into and out of unconsciousness are conserved no matter the context or precipitating conditions. We compared signatures of these mechanisms using intracranial electroencephalography in neurosurgical patients during propofol anesthesia and overnight sleep and found strikingly similar reorganization of human cortical networks. We computed the "effective dimensionality" of the normalized resting state functional connectivity matrix to quantify network complexity. Effective dimensionality decreased during stages of reduced consciousness (anesthesia unresponsiveness, N2 and N3 sleep). These changes were not region-specific, suggesting global network reorganization. When connectivity data were embedded into a low-dimensional space in which proximity represents functional similarity, we observed greater distances between brain regions during stages of reduced consciousness, and individual recording sites became closer to their nearest neighbors. These changes corresponded to decreased differentiation and functional integration and correlated with decreases in effective dimensionality. This network reorganization constitutes a neural signature of states of reduced consciousness that is common to anesthesia and sleep. These results establish a framework for understanding the neural correlates of consciousness and for practical evaluation of loss and recovery of consciousness.


Asunto(s)
Anestesia , Propofol , Humanos , Estado de Conciencia , Propofol/farmacología , Inconsciencia/inducido químicamente , Encéfalo , Sueño , Electroencefalografía
17.
Surg Endosc ; 38(6): 3470-3477, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38769187

RESUMEN

BACKGROUND: Soilage of the surgical endoscope occurs frequently during minimally invasive surgery. The resultant impairment of visualization of the surgical field compromises patient safety, prolongs operative times, and frustrates surgeons. The standard practice for cleaning the surgical camera involves a disruption in the conduct of surgery by completely removing the endoscope from the field, manually cleaning its lens, treating it with a surfactant, and reinserting it into the patient; after which the surgeon resumes the procedure. METHODS: We developed an automated solution for in vivo endoscope cleaning in minimally invasive surgery- a port that detects the position of the endoscope in its distal lumen, and precisely and automatically delivers a pressurized mist of cleaning solution to the lens of the camera. No additions to the scope and minimal user interaction with the port are required. We tested the efficacy of this troCarWash™ device in a porcine model of laparoscopy. Four board-certified general surgeons were instructed to soil and then clean the laparoscope using the device. Representative pre- and post-clean images were exported from the surgical video and clarity was graded (1) digitally by a canny edge detection algorithm, and (2) subjectively by 3 blinded, unbiased observers using a semi-quantitative scale. RESULTS: We observed statistically significant improvements in clarity by each method and for each surgeon, and we noted significant correlation between digital and subjective scores. CONCLUSION: Based on these data, we conclude that the troCarWash™ effectively restored impaired visualization in a large animal model of laparoscopy.


Asunto(s)
Laparoscopía , Laparoscopía/métodos , Laparoscopía/instrumentación , Animales , Porcinos , Laparoscopios , Contaminación de Equipos/prevención & control , Diseño de Equipo
18.
Surg Endosc ; 38(1): 348-355, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37783778

RESUMEN

BACKGROUND: Xanthogranulomatous cholecystitis (XGC) is an uncommon variant of chronic cholecystitis which can resemble gallbladder adenocarcinoma (GAC) on preoperative imaging and present technical challenges in the performance of cholecystectomy. We examined our experience with each pathology to identify distinguishing characteristics that may guide patient counseling and surgical management. METHODS: A retrospective review of all pathologically confirmed cases of XGC and GAC following cholecystectomy between 2015 and 2021 at a single institution was performed. Clinical, biochemical, radiographic, and intraoperative features were compared. RESULTS: There were 37 cases of XGC and 20 cases of GAC. Patients with GAC were older (mean 70.3 years vs 58.0, p = 0.01) and exclusively female (100% vs 45.9%, p < 0.0001). There were no significant differences in accompanying symptoms between groups (nausea/vomiting, fevers, or jaundice). The mean maximum white blood cell count was elevated for XGC compared to GAC (16.4 vs 8.6 respectively, p = 0.044); however, there were no differences in the remainder of the biochemical profile, including bilirubin, liver transaminases, CEA, and CA 19-9. The presence of an intraluminal mass (61.1% vs 9.1%, p = 0.0001) and lymphadenopathy (18.8%. vs 0.0%, p = 0.045) were associated with malignancy, whereas gallbladder wall thickening as reported on imaging (87.9% vs 38.9%, p = 0.0008) and gallstones (76.5% vs. 50.0%, p = 0.053) were more often present with XGC. Cases of XGC more often had significant adhesions/inflammation (83.8% vs 55.0%, p = 0.03). CONCLUSION: Clinical features that may favor benign chronic cholecystitis over gallbladder adenocarcinoma include younger age, male gender, current or prior leukocytosis, and the absence of an intraluminal mass or lymphadenopathy. Laparoscopic cholecystectomy is a safe surgical option for equivocal presentations. Intraoperative frozen section or intentional staging of more extensive procedures based upon final histopathology are valuable surgical strategies.


Asunto(s)
Adenocarcinoma , Colecistitis , Neoplasias de la Vesícula Biliar , Linfadenopatía , Xantomatosis , Humanos , Masculino , Femenino , Vesícula Biliar/cirugía , Colecistitis/diagnóstico , Colecistitis/cirugía , Neoplasias de la Vesícula Biliar/diagnóstico por imagen , Neoplasias de la Vesícula Biliar/cirugía , Xantomatosis/diagnóstico , Xantomatosis/cirugía , Adenocarcinoma/diagnóstico por imagen , Adenocarcinoma/cirugía , Linfadenopatía/patología
19.
Int J Gynecol Cancer ; 2024 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-39395821

RESUMEN

OBJECTIVES: T0 evaluate survival outcomes among patients with adult-type granulosa cell tumors who have telomerase reverse transcriptase (TERT) promoter mutations. METHODS: This is a retrospective cohort study using the MD Anderson Rare Gynecologic Malignancy Registry. Patients with adult granulosa cell tumors who underwent molecular testing for TERT promoter and FOXL2 c.C402G mutations were included. We used descriptive statistics to compare demographic and clinical variables and estimated progression-free and overall survival with Kaplan-Meier curves. Cox proportional hazards regression and log-rank tests were employed for comparisons, with multivariable analyses adjusting for various factors. RESULTS: Among 70 patients, 28 (40%) had TERT+ tumors. The median age at diagnosis was 40 years (range 12-71) for TERT- patients and 46 years (range 25-76) for TERT+ patients. At diagnosis, 22 (63%) of 35 TERT- patients were stage I, 10 (29%) stage II, and 3 (9%) stage III, while in the TERT+ group, 17/23 (74%) were stage I, 3 (13%) stage II, and 3 (13%) stage II. Univariable analysis showed no difference in time from diagnosis to first recurrence (p=0.19) and from first recurrence to second recurrence (p=0.24) based on tumor TERT status. The median time from first to second recurrence in the TERT- group was 27.3 months (95% CI 14.1 to 40.0) and in the TERT+ group was 14.8 months (95% CI 8.1 to 21.0). There was no observed difference in overall survival between the groups (HR=0.53; 95% CI 0.19 to 1.45; p=0.21). Multivariable analysis adjusting for age at diagnosis, TERT promoter mutation status, systemic chemotherapy, and stage demonstrated a significant difference in progression-free survival based on TERT mutation status (HR=2.89; 95% CI 1.32 to 6.36). CONCLUSIONS: After adjustment for covariates, patients with adult granulosa cell tumors and TERT+ tumors had shorter progression-free survival after first recurrence. TERT promoter mutations may identify a subset of patients with recurrent adult granulosa cell tumors and less favorable outcomes.

20.
Int J Gynecol Cancer ; 2024 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-39322610

RESUMEN

OBJECTIVES: As cervical cancer screening programs are implemented and expanded, an increasing number of women require loop electrosurgical excision procedure (LEEP) for treatment of pre-invasive cervical disease. Our objective was to describe the pathological results of LEEP specimens performed as part of the MULHER study and identify factors associated with positive LEEP margins. METHODS: The MULHER study enrolled 9014 women who underwent HPV testing followed by visual assessment for treatment (VAT) using visual inspection with acetic acid (VIA) and thermal ablation for those with positive results. Participants with lesions ineligible for ablation underwent LEEP. Pathology reports were reviewed for specimen size/volume, number of fragments, pathological diagnosis and margin status. Multivariable regression analysis was performed to identify variables associated with positive LEEP margins. RESULTS: 169 participants underwent LEEP. The median age was 38 years (range 30-49). 65.1% were women living with HIV. Pathological diagnosis was available for 154 patients and included cancer (n=6, 3.9%); cervical intraepithelial neoplasia (CIN) 2/3 (n=75, 48.7%); CIN 1 (n=67, 43.5%); and normal/benign findings (n=6,3.9%). 31.8% of LEEP specimens were removed in more than one fragment. The mean specimen volume was 2.9 cm3 (range 0.2-15.0). LEEP margin status was available for 130 patients. Positive margins (ectocervical/endocervical only, or both) were noted in 76 (58.5%) patients and associated with HIV+status (p=0.0499) and a diagnosis of CIN 2 or worse (p=0.0197). There were no associations between margin status and age, number of fragments or specimen volume. CONCLUSION: Our results showed a high number of LEEP specimens with positive margins. Additional evaluation is needed to better understand the characteristics of precancerous cervical lesions in this high-risk population. As cervical cancer screening programs are scaled in Mozambique and other lower-resource countries, there is a need to train providers to perform high-quality LEEP and for accurate and timely pathological interpretation.

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