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1.
bioRxiv ; 2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38979259

RESUMEN

Corticospinal neurons (CSNs) are located in the cortex and projecting into the spinal cord. The activation of CSNs, which is associated with skilled motor behaviors, induces the activation of interneurons in the spinal cord. Eventually, motor neuron activation is induced by corticospinal circuits to coordinate muscle activation. Therefore, elucidating how the activation of CSNs in the brain is regulated is necessary for understanding the roles of CSNs in skilled motor behaviors. However, the presynaptic partners of CSNs in the brain remain to be identified. Here, we performed transsynaptic rabies virus-mediated brain-wide mapping to identify presynaptic partners of CSNs (pre-CSNs). We found that pre-CSNs are located in all cortical layers, but major pre-CSNs are located in layer Va. A small population of pre-CSNs are also located outside the cortex, such as in the thalamus. Inactivation of layer Va neurons in Tlx3-Cre mice results in deficits in skilled reaching and grasping behaviors, suggesting that, similar to CSNs, layer Va neurons are critical for skilled movements. Finally, we examined whether the connectivity of CSNs is altered after spinal cord injury (SCI). We found that unlike connections between CNSs and postsynaptic neurons, connections between pre-CSNs and CSNs do not change after SCI.

2.
Nat Immunol ; 2024 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-38992254

RESUMEN

Upregulation of diverse self-antigens that constitute components of the inflammatory response overlaps spatially and temporally with the emergence of pathogen-derived foreign antigens. Therefore, discrimination between these inflammation-associated self-antigens and pathogen-derived molecules represents a unique challenge for the adaptive immune system. Here, we demonstrate that CD8+ T cell tolerance to T cell-derived inflammation-associated self-antigens is efficiently induced in the thymus and supported by redundancy in cell types expressing these molecules. In addition to thymic epithelial cells, this included thymic eosinophils and innate-like T cells, a population that expressed molecules characteristic for all major activated T cell subsets. We show that direct T cell-to-T cell antigen presentation by minute numbers of innate-like T cells was sufficient to eliminate autoreactive CD8+ thymocytes. Tolerance to such effector molecules was of critical importance, as its breach caused by decreased thymic abundance of a single model inflammation-associated self-antigen resulted in autoimmune elimination of an entire class of effector T cells.

3.
bioRxiv ; 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-39005321

RESUMEN

Friedreich's ataxia (FRDA) is one of the most common hereditary ataxias. It is caused by a GAA repeat in the first intron of the FXN gene, which encodes an essential mitochondrial protein. Patients suffer from progressive motor dysfunction due to the degeneration of mechanoreceptive and proprioceptive neurons in dorsal root ganglia (DRG) and cerebellar dentate nucleus neurons, especially at early disease stages. Postmortem analyses of FRDA patients also indicate pathological changes in motor cortex including in the projection neurons that give rise to the cortical spinal tract (CST). Yet, it remains poorly understood how early in the disease cortical spinal neurons (CSNs) show these alterations, or whether CSN/CST pathology resembles the abnormalities observed in other tissues affected by FXN loss. To address these questions, we examined CSN driven motor behaviors and pathology in the YG8JR FRDA mouse model. We find that FRDA mice show impaired motor skills, exhibit significant reductions in CSN functional output, and, among other pathological changes, show abnormal mitochondrial distributions in CSN neurons and CST axonal tracts. Moreover, some of these alterations were observed as early as two months of age, suggesting that CSN/CST pathology may be an earlier event in FRDA disease than previously appreciated. These studies warrant a detailed mechanistic understanding of how FXN loss impacts CSN health and functionality.

4.
Nat Commun ; 15(1): 5058, 2024 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-38871682

RESUMEN

In this study, high-performance organic photodetectors are presented which utilize a pristine chlorinated subphthalocyanine photoactive layer. Optical and optoelectronic analyses indicate that the device photocurrent is primarily generated through direct charge generation within the chlorinated subphthalocyanine layer, rather than exciton separation at layer interfaces. Molecular modelling suggests that this direct charge generation is facilitated by chlorinated subphthalocyanine high octupole moment (-80 DÅ2), which generates a 200 meV shift in molecular energetics. Increasing the thickness of chlorinated subphthalocyanine leads to faster response time, correlated with a decrease in trap density. Notably, photodetectors with a 50 nm thick chlorinated subphthalocyanine photoactive layer exhibit detectivities approaching 1013 Jones, with a dark current below 10-7 A cm-2 up to -5 V. Based on these findings, we conclude that high octupole moment molecular semiconductors are promising materials for high-performance organic photodetectors employing single-component photoactive layer.

5.
JCI Insight ; 9(13)2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38833310

RESUMEN

Patients with autoimmune diseases are at higher risk for severe infection due to their underlying disease and immunosuppressive treatments. In this real-world observational study of 463 patients with autoimmune diseases, we examined risk factors for poor B and T cell responses to SARS-CoV-2 vaccination. We show a high frequency of inadequate anti-spike IgG responses to vaccination and boosting in the autoimmune population but minimal suppression of T cell responses. Low IgG responses in B cell-depleted patients with multiple sclerosis (MS) were associated with higher CD8 T cell responses. By contrast, patients taking mycophenolate mofetil (MMF) exhibited concordant suppression of B and T cell responses. Treatments with highest risk for low anti-spike IgG response included B cell depletion within the last year, fingolimod, and combination treatment with MMF and belimumab. Our data show that the mRNA-1273 (Moderna) vaccine is the most effective vaccine in the autoimmune population. There was minimal induction of either disease flares or autoantibodies by vaccination and no significant effect of preexisting anti-type I IFN antibodies on either vaccine response or breakthrough infections. The low frequency of breakthrough infections and lack of SARS-CoV-2-related deaths suggest that T cell immunity contributes to protection in autoimmune disease.


Asunto(s)
Enfermedades Autoinmunes , Vacunas contra la COVID-19 , COVID-19 , SARS-CoV-2 , Humanos , COVID-19/inmunología , COVID-19/prevención & control , Femenino , SARS-CoV-2/inmunología , Masculino , Enfermedades Autoinmunes/inmunología , Persona de Mediana Edad , Adulto , Vacunas contra la COVID-19/inmunología , Inmunosupresores/uso terapéutico , Inmunoglobulina G/inmunología , Inmunoglobulina G/sangre , Vacuna nCoV-2019 mRNA-1273/inmunología , Vacuna nCoV-2019 mRNA-1273/administración & dosificación , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/sangre , Ácido Micofenólico/uso terapéutico , Anciano , Vacunación , Linfocitos B/inmunología , Anticuerpos Monoclonales Humanizados/uso terapéutico , Linfocitos T CD8-positivos/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología
6.
J Am Chem Soc ; 146(22): 15376-15392, 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38771156

RESUMEN

Couplings between vibrational motions are driven by electronic interactions, and these couplings carry special significance in vibrational energy transfer, multidimensional spectroscopy experiments, and simulations of vibrational spectra. In this investigation, the many-body contributions to these couplings are analyzed computationally in the context of clathrate-like alkali metal cation hydrates, including Cs+(H2O)20, Rb+(H2O)20, and K+(H2O)20, using both analytic and quantum-chemistry potential energy surfaces. Although the harmonic spectra and one-dimensional anharmonic spectra depend strongly on these many-body interactions, the mode-pair couplings were, perhaps surprisingly, found to be dominated by one-body effects, even in cases of couplings to low-frequency modes that involved the motion of multiple water molecules. The origin of this effect was traced mainly to geometric distortion within water monomers and cancellation of many-body effects in differential couplings, and the effect was also shown to be agnostic to the identity of the ion. These outcomes provide new understanding of vibrational couplings and suggest the possibility of improved computational methods for the simulation of infrared and Raman spectra.

7.
Transplant Rev (Orlando) ; 38(3): 100858, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38729062

RESUMEN

INTRODUCTION: Persistent findings suggest women and patients identified as "female" are less likely to receive a kidney transplant. Furthermore, the limited research on transplantation among transgender and gender diverse people suggests this population is susceptible to many of the same psychosocial and systemic barriers. OBJECTIVE: This review sought to 1) highlight terminology used to elucidate gender disparities, 2) identify barriers present along the steps to transplantation, and 3) summarize contributors to gender disparities across the steps to transplantation. METHODS: A systematic review of gender and sex disparities in the steps towards kidney transplantation was conducted in accordance with PRISMA guidelines across four social science and public health databases from 2005 to 23. RESULTS: The search yielded 1696 initial results, 33 of which met inclusion criteria. A majority of studies followed a retrospective cohort design (n = 22, 66.7%), inconsistently used gender and sex related terminology (n = 21, 63.6%), and reported significant findings for gender and sex disparities within the steps towards transplantation (n = 28, 84.8%). Gender disparities among the earlier steps were characterized by patient-provider communication and perception of medical suitability whereas disparities in the later steps were characterized by differential outcomes based on older age, an above average BMI, and Black racial identity. Findings for transgender patients pointed to issues computing eGFR and the need for culturally tailored care. DISCUSSION: Providers should be encouraged to critically examine the diagnostic criteria used to determine transplant eligibility and adopt practices that can be culturally tailored to meet the needs of patients.


Asunto(s)
Disparidades en Atención de Salud , Trasplante de Riñón , Humanos , Estados Unidos , Femenino , Masculino , Factores Sexuales , Fallo Renal Crónico/cirugía
8.
Nat Commun ; 15(1): 4560, 2024 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-38811556

RESUMEN

Gene drive systems could be a viable strategy to prevent pathogen transmission or suppress vector populations by propagating drive alleles with super-Mendelian inheritance. CRISPR-based homing gene drives convert wild type alleles into drive alleles in heterozygotes with Cas9 and gRNA. It is thus desirable to identify Cas9 promoters that yield high drive conversion rates, minimize the formation rate of resistance alleles in both the germline and the early embryo, and limit somatic Cas9 expression. In Drosophila, the nanos promoter avoids leaky somatic expression, but at the cost of high embryo resistance from maternally deposited Cas9. To improve drive efficiency, we test eleven Drosophila melanogaster germline promoters. Some achieve higher drive conversion efficiency with minimal embryo resistance, but none completely avoid somatic expression. However, such somatic expression often does not carry detectable fitness costs for a rescue homing drive targeting a haplolethal gene, suggesting somatic drive conversion. Supporting a 4-gRNA suppression drive, one promoter leads to a low drive equilibrium frequency due to fitness costs from somatic expression, but the other outperforms nanos, resulting in successful suppression of the cage population. Overall, these Cas9 promoters hold advantages for homing drives in Drosophila species and may possess valuable homologs in other organisms.


Asunto(s)
Sistemas CRISPR-Cas , Proteínas de Drosophila , Drosophila melanogaster , Tecnología de Genética Dirigida , Células Germinativas , Regiones Promotoras Genéticas , ARN Guía de Sistemas CRISPR-Cas , Animales , Regiones Promotoras Genéticas/genética , Drosophila melanogaster/genética , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Tecnología de Genética Dirigida/métodos , Células Germinativas/metabolismo , ARN Guía de Sistemas CRISPR-Cas/genética , Animales Modificados Genéticamente , Proteína 9 Asociada a CRISPR/metabolismo , Proteína 9 Asociada a CRISPR/genética , Alelos , Femenino , Masculino , Proteínas de Unión al ARN
9.
JCI Insight ; 9(5)2024 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-38456511

RESUMEN

Understanding the immune responses to SARS-CoV-2 vaccination is critical to optimizing vaccination strategies for individuals with autoimmune diseases, such as systemic lupus erythematosus (SLE). Here, we comprehensively analyzed innate and adaptive immune responses in 19 patients with SLE receiving a complete 2-dose Pfizer-BioNTech mRNA vaccine (BNT162b2) regimen compared with a control cohort of 56 healthy control (HC) volunteers. Patients with SLE exhibited impaired neutralizing antibody production and antigen-specific CD4+ and CD8+ T cell responses relative to HC. Interestingly, antibody responses were only altered in patients with SLE treated with immunosuppressive therapies, whereas impairment of antigen-specific CD4+ and CD8+ T cell numbers was independent of medication. Patients with SLE also displayed reduced levels of circulating CXC motif chemokine ligands, CXCL9, CXCL10, CXCL11, and IFN-γ after secondary vaccination as well as downregulation of gene expression pathways indicative of compromised innate immune responses. Single-cell RNA-Seq analysis reveals that patients with SLE showed reduced levels of a vaccine-inducible monocyte population characterized by overexpression of IFN-response transcription factors. Thus, although 2 doses of BNT162b2 induced relatively robust immune responses in patients with SLE, our data demonstrate impairment of both innate and adaptive immune responses relative to HC, highlighting a need for population-specific vaccination studies.


Asunto(s)
COVID-19 , Lupus Eritematoso Sistémico , Humanos , Vacuna BNT162 , Vacunas contra la COVID-19 , SARS-CoV-2 , COVID-19/prevención & control , Vacunación
10.
J Am Chem Soc ; 146(13): 8895-8903, 2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38511265

RESUMEN

Actin is one of the most abundant proteins in eukaryotic cells and is a key component of the cytoskeleton. A range of small molecules has emerged that interfere with actin dynamics by either binding to polymeric F-actin or monomeric G-actin to stabilize or destabilize filaments or prevent their formation and growth, respectively. Among these, the latrunculins, which bind to G-actin and affect polymerization, are widely used as tools to investigate actin-dependent cellular processes. Here, we report a photoswitchable version of latrunculin, termed opto-latrunculin (OptoLat), which binds to G-actin in a light-dependent fashion and affords optical control over actin polymerization. OptoLat can be activated with 390-490 nm pulsed light and rapidly relaxes to its inactive form in the dark. Light activated OptoLat induced depolymerization of F-actin networks in oligodendrocytes and budding yeast, as shown by fluorescence microscopy. Subcellular control of actin dynamics in human cancer cell lines was demonstrated via live cell imaging. Light-activated OptoLat also reduced microglia surveillance in organotypic mouse brain slices while ramification was not affected. Incubation in the dark did not alter the structural and functional integrity of the microglia. Together, our data demonstrate that OptoLat is a useful tool for the elucidation of G-actin dependent dynamic processes in cells and tissues.


Asunto(s)
Citoesqueleto de Actina , Actinas , Animales , Ratones , Humanos , Actinas/química , Citoesqueleto de Actina/metabolismo , Citoesqueleto/metabolismo , Línea Celular , Microtúbulos/metabolismo
11.
Am J Obstet Gynecol ; 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38432418

RESUMEN

OBJECTIVE: This study aimed to systematically review objective and subjective success and surgical outcomes of suburethral sling surgery for female patients with stress or mixed urinary incontinence using synthetic vs nonsynthetic material with corresponding surgical approaches (retropubic or transobturator). DATA SOURCES: We systematically searched Medline, Embase, EBM Reviews, ClinicalTrials.gov, and Web of Science Core Collection using standardized Medical Subject Headings (MeSH) without date restrictions (PROSPERO-registered). We double-screened studies and used backward citation chaining. STUDY ELIGIBILITY CRITERIA: We included peer-reviewed randomized controlled trials and prospective or retrospective comparative studies examining outcomes of retropubic or transobturator synthetic vs nonsynthetic (autologous, allograft, or xenograft) slings for female stress or mixed urinary incontinence, with available English or French full texts. We excluded minislings (single insertion point). We allowed slings for recurrent stress or mixed urinary incontinence, and slings concomitant with prolapse surgery, with at least 6 weeks of postoperative follow-up. We excluded systematic reviews, meta-analyses, review studies, case-control studies, case reports, studies that did not describe surgical approach or material, and studies of combination slings. METHODS: We evaluated study quality using RoB, the Cochrane risk-of-bias tool for randomized controlled trials, and the Newcastle-Ottawa scale for observational studies. We used pooled relative risk with 95% confidence intervals to estimate the effect of sling material type on each outcome through meta-analysis and meta-regression, as appropriate. RESULTS: We screened 4341 abstracts, assessed 104 full texts, and retained 35 articles (30 separate studies). For retropubic synthetic vs nonsynthetic slings, there was no difference in the number of objectively or subjectively continent patients. The rates of reoperation for stress urinary incontinence and overall were higher with nonautologous retropubic slings than with synthetic slings. Compared with autologous slings, retropubic synthetic slings were associated with higher subjective continence in populations with ≥25% recurrent stress urinary incontinence (relative risk, 1.27; 95% confidence interval, 1.12-1.43). There were no differences in continence between transobturator synthetic and nonsynthetic slings. Subjective satisfaction was better in the transobturator synthetic group than in the autologous sling group (relative risk, 1.42; 95% confidence interval, 1.03-1.94). CONCLUSION: Synthetic and nonsynthetic slings have comparable objective and subjective success, with synthetic materials generally showing better operative outcomes and fewer complications.

12.
Pediatr Cardiol ; 45(2): 361-367, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38062259

RESUMEN

Sinus node dysfunction (SND) with junctional rhythm (JR) is common after the Fontan operation. Atrial pacing (AP) restores atrioventricular (AV) synchrony, but the placement of a pacemaker carries significant morbidity. To study the impact of AP on echocardiographic parameters of function in Fontan patients with SND and JR. Nine Fontan patients with AP for SND and JR were prospectively studied with echocardiography in the following conditions-baseline paced rhythm, underlying JR and, if possible, slow-paced rhythm below their baseline paced rate (~ 10 bpm faster than their JR rate). Cardiac index was significantly lower in JR (3 ± 1.1 L/min/m2) vs AP (4.2 ± 1.4 L/min/m2; p = 0.002). Diastolic function also significantly worsened with increased ratio of early diastolic systemic AV valve inflow velocity to early diastolic systemic AV valve annulus velocity (E/e' ratio) by tissue Doppler imaging (TDI) in JR (11.6 ± 4.6) vs AP (8.8 ± 2.2, p = 0.016). Pulmonary venous flow reversal was present in 7/9 patients in JR vs 0/9 in AP (p = 0.016). There were no significant differences in these echocardiographic measurements between the paced and slow-paced conditions. When compared to AP, JR was associated with a significant reduction in cardiac output and diastolic function, and an increased prevalence of pulmonary vein flow reversal. There were no differences between paced and slow-paced conditions, suggesting that AV synchrony rather than heart rate was primarily contributing to cardiac output. Further studies are needed to understand the chronic impact of JR on Fontan outcomes.


Asunto(s)
Estimulación Cardíaca Artificial , Ecocardiografía , Humanos , Estudios Prospectivos , Estimulación Cardíaca Artificial/métodos , Atrios Cardíacos/diagnóstico por imagen , Arritmias Cardíacas , Síndrome del Seno Enfermo
13.
Cancer ; 130(3): 344-355, 2024 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-37962199

RESUMEN

Fertility is a top concern for many survivors of cancer diagnosed as children, adolescents and young adults (CAYA). Fertility preservation (FP) treatments are effective, evidence-based interventions to support their family building goals. Fertility discussions are a part of quality oncology care throughout the cancer care continuum. For nearly 2 decades, clinical guidelines recommend counseling patients about the possibility of infertility promptly at diagnosis and offering FP options and referrals as indicated. Multiple guidelines now recommend post-treatment counseling. Infertility risks differ by cancer treatments and age, rendering risk stratification a central part of FP care. To support FP decision-making, online tools for female risk estimation are available. At diagnosis, females can engage in mature oocyte/embryo cryopreservation, ovarian tissue cryopreservation, ovarian suppression with GnRH agonists, in vitro oocyte maturation, and/or conservative management for gynecologic cancers. Post-treatment, several populations may consider undergoing oocyte/embryo cryopreservation. Male survivors' standard of care FP treatments center on sperm cryopreservation before cancer treatment and do not have the same post-treatment indication for additional gamete cryopreservation. In practice, FP care requires systemized processes to routinely screen for FP needs, bridge oncology referrals to fertility, offer timely fertility consultations and access to FP treatments, and support financial navigation. Sixteen US states passed laws requiring health insurers to provide insurance benefits for FP treatments, but variation among the laws and downstream implementation are barriers to accessing FP treatments. To preserve the reproductive futures of CAYA survivors, research is needed to improve risk stratification, FP options, and delivery of FP care.


Asunto(s)
Preservación de la Fertilidad , Neoplasias de los Genitales Femeninos , Infertilidad , Neoplasias , Niño , Humanos , Masculino , Femenino , Adolescente , Adulto Joven , Semen , Criopreservación , Neoplasias/complicaciones , Neoplasias/terapia , Neoplasias/psicología , Infertilidad/etiología , Infertilidad/prevención & control
14.
IUBMB Life ; 76(2): 72-87, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37731280

RESUMEN

Mitochondria are essential for normal cellular function and have emerged as key aging determinants. Indeed, defects in mitochondrial function have been linked to cardiovascular, skeletal muscle and neurodegenerative diseases, premature aging, and age-linked diseases. Here, we describe mechanisms for mitochondrial protein and organelle quality control. These surveillance mechanisms mediate repair or degradation of damaged or mistargeted mitochondrial proteins, segregate mitochondria based on their functional state during asymmetric cell division, and modulate cellular fitness, the response to stress, and lifespan control in yeast and other eukaryotes.


Asunto(s)
Proteínas Mitocondriales , Saccharomycetales , Proteínas Mitocondriales/genética , Proteínas Mitocondriales/metabolismo , Saccharomycetales/genética , Saccharomycetales/metabolismo , Mitocondrias/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Control de Calidad , Especies Reactivas de Oxígeno/metabolismo
15.
Heliyon ; 9(12): e22688, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38058434

RESUMEN

Machine learning (ML) and citizen science (CS) are increasingly prevalent and rapidly evolving approaches to studying and managing environmental challenges. Municipal and other governance actors can benefit from technology advances in ML and public engagement benefits of CS but must also address validity and other quality assurance concerns in their application to particular management contexts. In this article, we take up the pervasive challenge of urban litter to demonstrate how ML can support CS by providing quality assurance in the regulatory context of California's stormwater program. We gave quantitative CS-collected data to five ML models to compare their predictions of a qualitative, site-specific, multiclass "Litter Index" score, an important regulatory metric typically only assessed by trained experts. XGBoost had the best outcome, with scores of 0.98 for accuracy, precision, recall and F-1. These strong results show that ML can provide a reliable complement to CS assessments and increase quality assurance in a regulatory context. To date, ML and CS have each contributed to litter management in novel ways and we find that their integration can provide important synergies with additional applications in other environmental management domains.

16.
J Chem Phys ; 159(20)2023 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-38010326

RESUMEN

Simulations of anharmonic vibrational motion rely on computationally expedient representations of the governing potential energy surface. The n-mode representation (n-MR)-effectively a many-body expansion in the space of molecular vibrations-is a general and efficient approach that is often used for this purpose in vibrational self-consistent field (VSCF) calculations and correlated analogues thereof. In the present analysis, a lack of convergence in many VSCF calculations is shown to originate from negative and unbound potentials at truncated orders of the n-MR expansion. For cases of strong anharmonic coupling between modes, the n-MR can both dip below the true global minimum of the potential surface and lead to effective single-mode potentials in VSCF that do not correspond to bound vibrational problems, even for bound total potentials. The present analysis serves mainly as a pathology report of this issue. Furthermore, this insight into the origin of VSCF non-convergence provides a simple, albeit ad hoc, route to correct the problem by "painting in" the full representation of groups of modes that exhibit these negative potentials at little additional computational cost. Somewhat surprisingly, this approach also reasonably approximates the results of the next-higher n-MR order and identifies groups of modes with particularly strong coupling. The method is shown to identify and correct problematic triples of modes-and restore SCF convergence-in two-mode representations of challenging test systems, including the water dimer and trimer, as well as protonated tropine.

17.
Nat Commun ; 14(1): 6941, 2023 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-37907556

RESUMEN

Circumstantial evidence suggests that B cells may instruct T cells to break tolerance. Here, to test this hypothesis, we used a murine model in which a single B cell clone precipitates an autoreactive response resembling systemic lupus erythematosus (SLE). The initiating clone did not need to enter germinal centers to precipitate epitope spreading. Rather, it localized to extrafollicular splenic bridging channels early in the response. Autoantibody produced by the initiating clone was not sufficient to drive the autoreactive response. Subsequent epitope spreading depended on antigen presentation and was compartmentalized by major histocompatibility complex (MHC). B cells carrying two MHC haplotypes could bridge the MHC barrier between B cells that did not share MHC. Thus, B cells directly relay autoreactivity between two separate compartments of MHC-restricted T cells, leading to inclusion of distinct B cell populations in germinal centers. Our findings demonstrate that B cells initiate and propagate the autoimmune response.


Asunto(s)
Presentación de Antígeno , Lupus Eritematoso Sistémico , Ratones , Animales , Epítopos , Antígenos de Histocompatibilidad Clase II/genética , Linfocitos B , Complejo Mayor de Histocompatibilidad , Antígenos de Histocompatibilidad
18.
Semin Perinatol ; 47(8): 151838, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37858459

RESUMEN

Increased fossil fuel usage and extreme climate change events have led to global increases in greenhouse gases and particulate matter with 99% of the world's population now breathing polluted air that exceeds the World Health Organization's recommended limits. Pregnant women and neonates with exposure to high levels of air pollutants are at increased risk of adverse health outcomes such as maternal hypertensive disorders, postpartum depression, placental abruption, low birth weight, preterm birth, infant mortality, and adverse lung and respiratory effects. While the exact mechanism by which air pollution exerts adverse health effects is unknown, oxidative stress as well as epigenetic and immune mechanisms are thought to play roles. Comprehensive, global efforts are urgently required to tackle the health challenges posed by air pollution through policies and action for reducing air pollution as well as finding ways to protect the health of vulnerable populations in the face of increasing air pollution.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Nacimiento Prematuro , Lactante , Femenino , Recién Nacido , Embarazo , Humanos , Nacimiento Prematuro/epidemiología , Placenta , Contaminación del Aire/efectos adversos , Contaminación del Aire/análisis , Contaminantes Atmosféricos/toxicidad , Contaminantes Atmosféricos/análisis , Material Particulado/efectos adversos , Material Particulado/análisis , Resultado del Embarazo/epidemiología
19.
Cell ; 186(21): 4632-4651.e23, 2023 10 12.
Artículo en Inglés | MEDLINE | ID: mdl-37776858

RESUMEN

The dynamics of immunity to infection in infants remain obscure. Here, we used a multi-omics approach to perform a longitudinal analysis of immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in infants and young children by analyzing blood samples and weekly nasal swabs collected before, during, and after infection with Omicron and non-Omicron variants. Infection stimulated robust antibody titers that, unlike in adults, showed no sign of decay for up to 300 days. Infants mounted a robust mucosal immune response characterized by inflammatory cytokines, interferon (IFN) α, and T helper (Th) 17 and neutrophil markers (interleukin [IL]-17, IL-8, and CXCL1). The immune response in blood was characterized by upregulation of activation markers on innate cells, no inflammatory cytokines, but several chemokines and IFNα. The latter correlated with viral load and expression of interferon-stimulated genes (ISGs) in myeloid cells measured by single-cell multi-omics. Together, these data provide a snapshot of immunity to infection during the initial weeks and months of life.


Asunto(s)
COVID-19 , SARS-CoV-2 , Adulto , Niño , Lactante , Humanos , Preescolar , SARS-CoV-2/metabolismo , Multiómica , Citocinas/metabolismo , Interferón-alfa , Inmunidad Mucosa
20.
J Chem Phys ; 159(8)2023 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-37606324

RESUMEN

The vibrational self-consistent field (VSCF) method yields anharmonic states and spectra for molecular vibrations, and it serves as the starting point for more sophisticated correlated-vibration methods. Convergence of the iterative, non-linear optimization in VSCF calculations can be erratic or altogether unsuccessful, particularly for chemical systems involving low-frequency motions. In this work, a vibrational formulation of the Direct Inversion of the Iterative Subspace method of Pulay is presented and investigated. This formulation accounts for distinct attributes of the vibrational and electronic cases, including the expansion of each single-mode vibrational wavefunction in its own basis set. The resulting Direct Inversion of the Iterative Subspace method is shown to substantially accelerate VSCF convergence in all convergent cases as well as rectify many cases where Roothaan-based methods fail. Performance across systems ranging from small, rigid molecules to weakly bound molecular clusters is investigated in this analysis.

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