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1.
bioRxiv ; 2024 Jul 03.
Article in English | MEDLINE | ID: mdl-39005260

ABSTRACT

Postural control circuitry performs the essential function of maintaining balance and body position in response to perturbations that are either self-generated (e.g. reaching to pick up an object) or externally delivered (e.g. being pushed by another person). Human studies have shown that anticipation of predictable postural disturbances can modulate such responses. This indicates that postural control could involve higher-level neural structures associated with predictive functions, rather than being purely reactive. However, the underlying neural circuitry remains largely unknown. To enable studies of predictive postural control circuits, we developed a novel task for mice. In this task, modeled after human studies, a dynamic platform generated reproducible translational perturbations. While mice stood bipedally atop a perch to receive water rewards, they experienced backward translations that were either unpredictable or preceded by an auditory cue. To validate the task, we investigated the effect of the auditory cue on postural responses to perturbations across multiple days in three mice. These preliminary results serve to validate a new postural control model, opening the door to the types of neural recordings and circuit manipulations that are currently possible only in mice.

2.
Front Aging Neurosci ; 16: 1396443, 2024.
Article in English | MEDLINE | ID: mdl-39015474

ABSTRACT

In recent years, microglia have been highlighted for playing integral roles in neurodegenerative diseases, like glaucoma. To better understand the role of microglia during chronic ocular hypertension, we depleted microglia from aged (9-12 months old) DBA/2 J (D2) mice, which exhibit age-related increases in intraocular pressure, using a dietary CSF1R antagonist, PLX5622. Retinal ganglion cell (RGC) somas were counted, and optic nerve cross-sections stained and assessed for glaucomatous damage. Sustained administration of dietary PLX5622 significantly reduced the numbers of retinal microglia. Dietary PLX5622 did not lead to changes in intraocular pressure in D2 or normotensive DBA/2 J-Gpnmb+ (D2-Gpnmb+ ) control mice. While PLX5622-treated D2-Gpnmb+ did not develop optic nerve damage, PLX5622-treated D2 mice showed a significant increase in moderate-to-severe optic nerve damage compared to D2 mice fed a control diet. In conclusion, global reduction of microglia exacerbated glaucomatous neurodegeneration in D2 mice suggesting microglia play an overall beneficial role in protecting from ocular hypertension associated RGC loss.

3.
JACC Case Rep ; 29(14): 102397, 2024 Jul 17.
Article in English | MEDLINE | ID: mdl-38952423

ABSTRACT

Right ventricular outflow tract (RVOT) obstruction is a rare complication of ventricular hypertrophy in patients with hypertrophic cardiomyopathy (HCM). This study presents an unusual case of a patient with HCM with severe RVOT obstruction that was relieved successfully through the use of mavacamten.

4.
Res Sq ; 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38947078

ABSTRACT

Background: The Borreliaceae family includes many obligate parasitic bacterial species which are etiologically associated with a myriad of zoonotic borrelioses including Lyme disease and vector-borne relapsing fevers. Infections by the Borreliaceae are difficult to detect by both direct and indirect methods, often leading to delayed and missed diagnoses. Efforts to improve diagnoses center around the development of molecular diagnostics (MDx), but due to deep tissue sequestration of the causative spirochaetes and the lack of persistent bacteremias, even MDx assays suffer from a lack of sensitivity. Additionally, the highly extensive genomic heterogeneity among isolates, even within the same species, contributes to the lack of assay sensitivity as single target assays cannot provide universal coverage. This within-species heterogeneity is partly due to differences in replicon repertoires and genomic structures that have likely arisen to support the complex Borreliaceae lifecycle in which these parasites have to survive in multiple hosts each with unique immune responses. Results: We constructed a Borreliaceae family-level pangenome and characterized the phylogenetic relationships among the constituent taxa which supports the recent taxonomy of splitting the family into at least two genera. Gene content pro les were created for the majority of the Borreliaceae replicons, providing for the first time their unambiguous molecular typing. Conclusion: Our characterization of the Borreliaceae pan-genome supports the splitting of the former Borrelia genus into two genera and provides for the phylogenetic placement of several non-species designated isolates. Mining this family-level pangenome will enable precision diagnostics corresponding to gene content-driven clinical outcomes while also providing targets for interventions.

5.
Nat Commun ; 15(1): 5822, 2024 Jul 11.
Article in English | MEDLINE | ID: mdl-38987289

ABSTRACT

DNA polymerase theta (Polθ)-mediated end-joining (TMEJ) repairs DNA double-strand breaks and confers resistance to genotoxic agents. How Polθ is regulated at the molecular level to exert TMEJ remains poorly characterized. We find that Polθ interacts with and is PARylated by PARP1 in a HPF1-independent manner. PARP1 recruits Polθ to the vicinity of DNA damage via PARylation dependent liquid demixing, however, PARylated Polθ cannot perform TMEJ due to its inability to bind DNA. PARG-mediated de-PARylation of Polθ reactivates its DNA binding and end-joining activities. Consistent with this, PARG is essential for TMEJ and the temporal recruitment of PARG to DNA damage corresponds with TMEJ activation and dissipation of PARP1 and PAR. In conclusion, we show a two-step spatiotemporal mechanism of TMEJ regulation. First, PARP1 PARylates Polθ and facilitates its recruitment to DNA damage sites in an inactivated state. PARG subsequently activates TMEJ by removing repressive PAR marks on Polθ.


Subject(s)
DNA Breaks, Double-Stranded , DNA End-Joining Repair , DNA Polymerase theta , DNA-Directed DNA Polymerase , Poly (ADP-Ribose) Polymerase-1 , Humans , Poly (ADP-Ribose) Polymerase-1/metabolism , Poly (ADP-Ribose) Polymerase-1/genetics , DNA-Directed DNA Polymerase/metabolism , Poly Adenosine Diphosphate Ribose/metabolism , DNA Damage , Animals , DNA-Binding Proteins/metabolism , DNA-Binding Proteins/genetics , DNA/metabolism , DNA/genetics , HEK293 Cells , Poly ADP Ribosylation , Poly(ADP-ribose) Polymerases/metabolism , Poly(ADP-ribose) Polymerases/genetics , Carrier Proteins , Glycoside Hydrolases , Nuclear Proteins
6.
Pediatr Qual Saf ; 9(4): e746, 2024.
Article in English | MEDLINE | ID: mdl-38993274

ABSTRACT

Introduction: Adherence to the American Academy of Pediatrics clinical practice guidelines for screening and managing high blood pressure (BP) is low. This team sought to improve recognition and documentation of relevant diagnoses in patients aged 13-20 years who presented to general pediatric clinics. Methods: The primary outcome measure was the proportion of office visits for patients ages 13-20 with a BP ≥ 120/80 with a visit or problem list diagnosis of hypertension or elevated BP. Secondary measures included (1) the proportion of patients who had their BP measured in the right arm, (2) the proportion of patients who had a mid-arm circumference measurement recorded, and (3) the proportion of patients who had a second BP reading measured at the visit. Interventions addressed key drivers for evidence-based high BP screening: standard BP measurement, electronic health record clinical decision support, and clinical pathway adoption. Data were collected over a twenty-seven-month period and plotted using the Laney p' chart. Results: Provider documentation of elevated BP or hypertension improved from a baseline mean of 24% in April 2020 through January 2022 to 41% in February 2021 through June 2022. All secondary outcome measures also demonstrated significant improvement. Conclusions: This project demonstrates the feasibility of improving adherence to best practices of BP measurement in primary care clinics through education, acquisition of resources, and implementation of electronic health record flags for abnormal values.

7.
medRxiv ; 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-39006445

ABSTRACT

The female reproductive lifespan depends on egg quality, particularly euploidy. Mistakes in meiosis leading to egg aneuploidy are common, but the genetic landscape causing this is not well understood due to limited phenotypic data. We identify genetic determinants of reproductive aging via egg aneuploidy using a biobank of maternal exomes linked with maternal age and embryonic aneuploidy data. We found 404 genes with variants enriched in individuals with high egg aneuploidy rates and implicate kinesin protein family genes in aneuploidy risk. Experimental perturbations showed that motor domain variants in these genes increase aneuploidy in mouse oocytes. A knock-in mouse model validated that a specific variant in kinesin KIF18A accelerates reproductive aging and diminishes fertility. These findings suggest potential non-invasive biomarkers for egg quality, aiding personalized fertility medicine. One sentence summary: The study identifies novel genetic determinants of reproductive aging linked to egg aneuploidy by analyzing maternal exomes and demonstrates that variants in kinesin genes, specifically KIF18A , contribute to increased aneuploidy and accelerated reproductive aging, offering potential for personalized fertility medicine.

8.
Eur Heart J ; 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-39011630

ABSTRACT

BACKGROUND AND AIMS: Pathogenic desmoplakin (DSP) gene variants are associated with the development of a distinct form of arrhythmogenic cardiomyopathy known as DSP cardiomyopathy. Patients harbouring these variants are at high risk for sustained ventricular arrhythmia (VA), but existing tools for individualized arrhythmic risk assessment have proven unreliable in this population. METHODS: Patients from the multi-national DSP-ERADOS (Desmoplakin SPecific Effort for a RAre Disease Outcome Study) Network patient registry who had pathogenic or likely pathogenic DSP variants and no sustained VA prior to enrolment were followed longitudinally for the development of first sustained VA event. Clinically guided, step-wise Cox regression analysis was used to develop a novel clinical tool predicting the development of incident VA. Model performance was assessed by c-statistic in both the model development cohort (n = 385) and in an external validation cohort (n = 86). RESULTS: In total, 471 DSP patients [mean age 37.8 years, 65.6% women, 38.6% probands, 26% with left ventricular ejection fraction (LVEF) < 50%] were followed for a median of 4.0 (interquartile range: 1.6-7.3) years; 71 experienced first sustained VA events {2.6% [95% confidence interval (CI): 2.0, 3.5] events/year}. Within the development cohort, five readily available clinical parameters were identified as independent predictors of VA and included in a novel DSP risk score: female sex [hazard ratio (HR) 1.9 (95% CI: 1.1-3.4)], history of non-sustained ventricular tachycardia [HR 1.7 (95% CI: 1.1-2.8)], natural logarithm of 24-h premature ventricular contraction burden [HR 1.3 (95% CI: 1.1-1.4)], LVEF < 50% [HR 1.5 (95% CI: .95-2.5)], and presence of moderate to severe right ventricular systolic dysfunction [HR 6.0 (95% CI: 2.9-12.5)]. The model demonstrated good risk discrimination within both the development [c-statistic .782 (95% CI: .77-.80)] and external validation [c-statistic .791 (95% CI: .75-.83)] cohorts. The negative predictive value for DSP patients in the external validation cohort deemed to be at low risk for VA (<5% at 5 years; n = 26) was 100%. CONCLUSIONS: The DSP risk score is a novel model that leverages readily available clinical parameters to provide individualized VA risk assessment for DSP patients. This tool may help guide decision-making for primary prevention implantable cardioverter-defibrillator placement in this high-risk population and supports a gene-first risk stratification approach.

9.
Mol Cell ; 2024 Jul 06.
Article in English | MEDLINE | ID: mdl-39013473

ABSTRACT

The human silencing hub (HUSH) preserves genome integrity through the epigenetic repression of invasive genetic elements. However, despite our understanding of HUSH as an obligate complex of three subunits, only loss of MPP8 or Periphilin, but not TASOR, triggers interferon signaling following derepression of endogenous retroelements. Here, we resolve this paradox by characterizing a second HUSH complex that shares MPP8 and Periphilin but assembles around TASOR2, an uncharacterized paralog of TASOR. Whereas HUSH represses LINE-1 retroelements marked by the repressive histone modification H3K9me3, HUSH2 is recruited by the transcription factor IRF2 to repress interferon-stimulated genes. Mechanistically, HUSH-mediated retroelement silencing sequesters the limited pool of the shared subunits MPP8 and Periphilin, preventing TASOR2 from forming HUSH2 complexes and hence relieving the HUSH2-mediated repression of interferon-stimulated genes. Thus, competition between two HUSH complexes intertwines retroelement silencing with the induction of an immune response, coupling epigenetic and immune aspects of genome defense.

10.
Hum Reprod ; 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38970367

ABSTRACT

Recent advances in preimplantation genetic testing for aneuploidy (PGT-A) have significantly enhanced its application in ART, providing critical insights into embryo viability, and potentially reducing both the time spent in fertility treatments and the risk of pregnancy loss. With the integration of next-generation sequencing, PGT-A now offers greater diagnostic precision, although challenges related to segmental aneuploidies and mosaicism remain. The emergence of non-invasive PGT-A (niPGT-A), which analyzes DNA in spent embryo culture media, promises a simpler aneuploidy screening method. This mini review assesses the methodological criteria for test validation, the current landscape of PGT-A, and the potential of niPGT-A, while evaluating its advantages and potential pitfalls. It underscores the importance of a robust three-phase validation process to ensure the clinical reliability of PGT-A. Despite initial encouraging data, niPGT-A not only confronts issues of DNA amplification failure and diagnostic inaccuracies but also has yet to meet the three-prong criteria required for appropriate test validation, necessitating further research for its clinical adoption. The review underscores that niPGT-A, like traditional PGT-A, must attain the high standards of precision and reliability expected of any genetic testing platform used in clinical settings before it can be adopted into routine ART protocols.

11.
Lancet Reg Health West Pac ; 48: 101119, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38974907

ABSTRACT

Background: Simplified hepatitis C virus (HCV) testing integrated into existing HIV services has the potential to improve HCV diagnoses and treatment. We evaluated the cost-effectiveness of integrating different simplified HCV testing strategies into existing HIV pre-exposure prophylaxis (PrEP) and treatment services among men who have sex with men (MSM) in Taiwan. Methods: Mathematical modeling was used to assess the cost-effectiveness of integrating simplified HCV tests (point-of-care antibody, reflex RNA, or immediate point-of-care RNA) with HCV treatment into existing HIV prevention and care for MSM from a healthcare perspective. The impact of increasing PrEP and HIV treatment coverage among MSM in combination with these HCV testing strategies was also considered. We reported lifetime costs (2022 US dollars) and quality-adjusted life years (QALYs) and calculated incremental cost-effectiveness ratios (ICERs) with a 3% annual discounting rate. Findings: Point-of-care HCV antibody and reflex RNA testing are cost-effective compared to current HCV testing in all PrEP and HIV treatment coverage scenarios (ICERs <$32,811/QALY gained). Immediate point-of-care RNA testing would be only cost-effective compared to the current HCV testing if coverage of HIV services remained unchanged. Point-of-care antibody testing in an unchanged HIV services coverage scenario and all simplified HCV testing strategies in scenarios that increased both HIV PrEP and treatment coverage form an efficient frontier, indicating best value for money strategies. Interpretation: Our findings support the integration of simplified HCV testing and people-centered services for MSM and highlight the economic benefits of integrating simplified HCV testing into existing services for MSM alongside HIV PrEP and treatment. Funding: This study was made possible as part of a research-funded PhD being undertaken by HJW under the UNSW Sydney Scientia scholarship and was associated with the Rapid Point of Care Research Consortium for infectious disease in the Asia Pacific (RAPID), which is funded by an NHMRC Centre for Research Excellence. JG is supported by a National Health and Medical Research Council Investigator Grant (1176131).

12.
F S Rep ; 5(2): 134-135, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38983725
13.
bioRxiv ; 2024 Mar 13.
Article in English | MEDLINE | ID: mdl-39005332

ABSTRACT

Pulmonary hypertension (PH) results in RV hypertrophy, fibrosis and dysfunction resulting in RV failure which is associated with impaired RV metabolism and mitochondrial respiration. Mitochondrial supercomplexes (mSC) are assemblies of multiple electron transport chain (ETC) complexes that consist of physically associated complex I, III and IV that may enhance respiration and lower ROS generation. The goal of this study was to determine if mSCs are reduced in RV dysfunction associated with PH. We induced PH in Sprague-Dawley rats by Sugen/Hypoxia (3 weeks) followed by normoxia (4 weeks). Control and PH rats were subjected to echocardiography, blue and clear native-PAGE to assess mSC abundance and activity, and cardiomyocyte isolation to assess mitochondrial reactive oxygen species (ROS). mSC formation was also assessed in explanted human hearts with and without RV dysfunction. RV activity of CI and CIV and abundance of CI, CIII and CIV in mitochondrial mSCs was severely reduced in PH rats compared to control. There were no differences in total CI or CIV activity or abundance in smaller ETC assemblies. There were no changes in both RV and LV of expression of representative ETC complex subunits. PAT, TAPSE and RV Wall thickness significantly correlated with CIV and CI activity in mSC, but not total CI and CIV activity in the RV. Consistent with reduced mSC activity, isolated PH RV myocytes had increased mitochondrial ROS generation compared to control. Reduced mSC activity was also demonstrated in explanted human RV tissue from patients undergoing cardiac transplant with RV dysfunction. The right atrial pressure/pulmonary capillary wedge pressure ratio (RAP/PCWP, an indicator of RV dysfunction) negatively correlated with RV mSC activity level. In conclusion, reduced assembly and activity of mitochondrial mSC is correlated with RV dysfunction in PH rats and humans with RV dysfunction.

14.
Int J Epidemiol ; 53(4)2024 Jun 12.
Article in English | MEDLINE | ID: mdl-38961644

ABSTRACT

BACKGROUND: Numerous studies have linked fine particulate matter (PM2.5) to increased cardiovascular mortality. Less is known how the PM2.5-cardiovascular mortality association varies by use of cardiovascular medications. This study sought to quantify effect modification by statin use status on the associations between long-term exposure to PM2.5 and mortality from any cardiovascular cause, coronary heart disease (CHD), and stroke. METHODS: In this nested case-control study, we followed 1.2 million community-dwelling adults aged ≥66 years who lived in Ontario, Canada from 2000 through 2018. Cases were patients who died from the three causes. Each case was individually matched to up to 30 randomly selected controls using incidence density sampling. Conditional logistic regression models were used to estimate odds ratios (ORs) for the associations between PM2.5 and mortality. We evaluated the presence of effect modification considering both multiplicative (ratio of ORs) and additive scales (the relative excess risk due to interaction, RERI). RESULTS: Exposure to PM2.5 increased the risks for cardiovascular, CHD, and stroke mortality. For all three causes of death, compared with statin users, stronger PM2.5-mortality associations were observed among non-users [e.g. for cardiovascular mortality corresponding to each interquartile range increase in PM2.5, OR = 1.042 (95% CI, 1.032-1.053) vs OR = 1.009 (95% CI, 0.996-1.022) in users, ratio of ORs = 1.033 (95% CI, 1.019-1.047), RERI = 0.039 (95% CI, 0.025-0.050)]. Among users, partially adherent users exhibited a higher risk of PM2.5-associated mortality than fully adherent users. CONCLUSIONS: The associations of chronic exposure to PM2.5 with cardiovascular and CHD mortality were stronger among statin non-users compared to users.


Subject(s)
Cardiovascular Diseases , Hydroxymethylglutaryl-CoA Reductase Inhibitors , Particulate Matter , Humans , Particulate Matter/adverse effects , Particulate Matter/analysis , Male , Aged , Female , Hydroxymethylglutaryl-CoA Reductase Inhibitors/adverse effects , Case-Control Studies , Ontario/epidemiology , Cardiovascular Diseases/mortality , Aged, 80 and over , Coronary Disease/mortality , Coronary Disease/epidemiology , Stroke/mortality , Stroke/epidemiology , Environmental Exposure/adverse effects , Logistic Models , Risk Factors , Independent Living , Odds Ratio
15.
Transplant Cell Ther ; 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38972511

ABSTRACT

Follicular lymphoma (FL) is the most common indolent B-cell non-Hodgkin lymphoma (NHL), accounting for nearly one-third of all NHL. The therapeutic landscape for patients with FL has significantly expanded over the past decade, but the disease continues to be considered incurable. Hematopoietic cell transplantation (HCT) is potentially curative in some cases. Recently, the emergence of chimeric antigen receptor T-cell therapy (CAR-T) for patients with relapsed/refractory (R/R) FL has yielded impressive response rates and long-term remissions, but definitive statement on the curative potential of CAR-T is currently not possible due to limited patient numbers and relatively short follow up. A consensus on the contemporary role, optimal timing, and sequencing of HCT (autologous or allogeneic) and cellular therapies in FL is needed. As a result, the American Society of Transplantation and Cellular Therapy (ASTCT) Committee on Practice Guidelines endorsed this effort to formulate consensus recommendations to address this unmet need. The RAND-modified Delphi method was used to generate 15 consensus statements/recommendations. Of note, the use of bispecific antibodies in R/R FL was not in the scope of this project. Key statements/recommendations are as follows: 1) Autologous HCT is recommended as an option for consolidation therapy in patients with progression of untransformed disease within 24 months of front line chemoimmunotherapy and upon achieving a complete (CR) or partial response (PR) to salvage second line therapies; 2) CAR-T is considered as a treatment option for patients who did not achieve CR or PR after second or subsequent lines of therapies; 3) Allogeneic HCT is considered as consolidative treatment in relapsed FL patients with chemosensitive disease who have received 3 or more lines of systemic therapy and are the following clinical scenarios: post CAR-T failure; lack of access to CAR-T or have therapy related myeloid neoplasm. These clinical practice recommendations will help guide clinicians managing patients with FL.

16.
Urology ; 2024 Jul 17.
Article in English | MEDLINE | ID: mdl-39029806

ABSTRACT

OBJECTIVES: To investigate the cadence of recurrence in patients with low grade intermediate-risk non-muscle invasive bladder cancer (LG IR-NMIBC) based on clinical determinants. We aim to describe patterns in rates of recurrence to better inform surveillance regimens for this chronic, burdensome, and costly disease. METHODS: Using baseline and follow-up data from participants in the West Midlands' (United Kingdom, UK) Bladder Cancer Prognosis Programme (BCPP), we assessed overall recurrence rate and recurrence-free intervals throughout the follow-up period for IR-NMIBC participants. Recurrence-free intervals were calculated using the Kaplan-Meier method. RESULTS: We identified 379 patients with G1/G2 pTa tumors classified as intermediate risk. Median age was 70 and 284/379 (75%) were male. The median follow-up time was 4.2 years (95% CI: 3.9-4.8). After 5 years of follow-up, 53% of patients had at least one recurrence. One-year recurrence-free survival (RFS) was 75% and 4-year RFS was 50%. The median time to or between 1st, 2nd, 3rd, 4th, and 5th sequential recurrences was 49, 19, 12, 14, and 10 months, respectively. CONCLUSIONS: Over half of patients with IR-NMIBC are destined to recur. Our data suggest that a subset of patients experience acceleration of recurrence over time and that this acceleration may serve as a potential kinetic biomarker for these individuals that could inform surveillance intervals and future treatment strategies.

17.
JCI Insight ; 9(13)2024 May 21.
Article in English | MEDLINE | ID: mdl-38973611

ABSTRACT

Optimization of protective immune responses against SARS-CoV-2 remains an urgent worldwide priority. In this regard, type III IFN (IFN-λ) restricts SARS-CoV-2 infection in vitro, and treatment with IFN-λ limits infection, inflammation, and pathogenesis in murine models. Furthermore, IFN-λ has been developed for clinical use to limit COVID-19 severity. However, whether endogenous IFN-λ signaling has an effect on SARS-CoV-2 antiviral immunity and long-term immune protection in vivo is unknown. In this study, we identified a requirement for IFN-λ signaling in promoting viral clearance and protective immune programming in SARS-CoV-2 infection of mice. Expression of both IFN and IFN-stimulated gene (ISG) in the lungs were minimally affected by the absence of IFN-λ signaling and correlated with transient increases in viral titers. We found that IFN-λ supported the generation of protective CD8 T cell responses against SARS-CoV-2 by facilitating accumulation of CD103+ DC in lung draining lymph nodes (dLN). IFN-λ signaling specifically in DCs promoted the upregulation of costimulatory molecules and the proliferation of CD8 T cells. Intriguingly, antigen-specific CD8 T cell immunity to SARS-CoV-2 was independent of type I IFN signaling, revealing a nonredundant function of IFN-λ. Overall, these studies demonstrate a critical role for IFN-λ in protective innate and adaptive immunity upon infection with SARS-CoV-2 and suggest that IFN-λ serves as an immune adjuvant to support CD8 T cell immunity.


Subject(s)
CD8-Positive T-Lymphocytes , COVID-19 , Interferon Type I , SARS-CoV-2 , Animals , CD8-Positive T-Lymphocytes/immunology , SARS-CoV-2/immunology , Mice , COVID-19/immunology , COVID-19/virology , Interferon Type I/immunology , Interferon Type I/metabolism , Lung/immunology , Lung/virology , Signal Transduction/immunology , Disease Models, Animal , Interferon Lambda , Interferons/immunology , Interferons/metabolism , Mice, Inbred C57BL , Mice, Knockout , Dendritic Cells/immunology , Humans
18.
Sci Adv ; 10(29): eadn4613, 2024 Jul 19.
Article in English | MEDLINE | ID: mdl-39018415

ABSTRACT

Optically induced intersite spin transfer (OISTR) promises manipulation of spin systems within the ultimate time limit of laser excitation. Following its prediction, signatures of ultrafast spin transfer between oppositely aligned spin sublattices have been observed in magnetic alloys and multilayers. However, it is known neither from theory nor from experiment whether the band structure immediately follows the ultrafast change in spin polarization or whether the exchange split bands remain rigid. We show that ultrafast spin transfer occurs even in ferromagnetic gadolinium metal. Charge transfer between localized surface and extended valence-band states leads to a decrease of the surface spin polarization. This synchronously alters the exchange splitting of the bulk valence bands during laser excitation. Moreover, the onset of demagnetization can be tuned by over 200 fs by changing the temperature-dependent spin mixing. Our results show a promising route to ultrafast control of the magnetization, widening the impact and applicability of OISTR.

19.
bioRxiv ; 2024 Jun 07.
Article in English | MEDLINE | ID: mdl-38895274

ABSTRACT

DNA double-strand breaks (DSBs) present a critical threat to genomic integrity, often precipitating genomic instability and oncogenesis. Repair of DSBs predominantly occurs through homologous recombination (HR) and non-homologous end joining (NHEJ). In HR-deficient cells, DNA polymerase theta (Polθ) becomes critical for DSB repair via microhomology-mediated end joining (MMEJ), also termed theta-mediated end joining (TMEJ). Thus, Polθ is synthetically lethal with BRCA1/2 and other HR factors, underscoring its potential as a therapeutic target in HR-deficient cancers. However, the molecular mechanisms governing Polθ-mediated MMEJ remain poorly understood. Here we present a series of cryo-electron microscopy structures of the Polθ helicase domain (Polθ-hel) in complex with DNA containing 3'-overhang. The structures reveal the sequential conformations adopted by Polθ-hel during the critical phases of DNA binding, microhomology searching, and microhomology annealing. The stepwise conformational changes within the Polθ-hel subdomains and its functional dimeric state are pivotal for aligning the 3'-overhangs, facilitating the microhomology search and subsequent annealing necessary for DSB repair via MMEJ. Our findings illustrate the essential molecular switches within Polθ-hel that orchestrate the MMEJ process in DSB repair, laying the groundwork for the development of targeted therapies against the Polθ-hel.

20.
Sci Eng Ethics ; 30(3): 23, 2024 Jun 04.
Article in English | MEDLINE | ID: mdl-38833046

ABSTRACT

The Defining Issues Test 2 (DIT-2) and Engineering Ethical Reasoning Instrument (EERI) are designed to measure ethical reasoning of general (DIT-2) and engineering-student (EERI) populations. These tools-and the DIT-2 especially-have gained wide usage for assessing the ethical reasoning of undergraduate students. This paper reports on a research study in which the ethical reasoning of first-year undergraduate engineering students at multiple universities was assessed with both of these tools. In addition to these two instruments, students were also asked to create personal concept maps of the phrase "ethical decision-making." It was hypothesized that students whose instrument scores reflected more postconventional levels of moral development and more sophisticated ethical reasoning skills would likewise have richer, more detailed concept maps of ethical decision-making, reflecting their deeper levels of understanding of this topic and the complex of related concepts. In fact, there was no significant correlation between the instrument scores and concept map scoring, suggesting that the way first-year students conceptualize ethical decision making does not predict the way they behave when performing scenario-based ethical reasoning (perhaps more situated). This disparity indicates a need to more precisely quantify engineering ethical reasoning and decision making, if we wish to inform assessment outcomes using the results of such quantitative analyses.


Subject(s)
Decision Making , Educational Measurement , Engineering , Students , Humans , Engineering/ethics , Engineering/education , Decision Making/ethics , Universities , Thinking , Morals , Moral Development , Male , Female , Ethics, Professional/education , Problem Solving/ethics
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