Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 1.204
Filter
1.
Mol Cancer Res ; 2024 Jul 17.
Article in English | MEDLINE | ID: mdl-39018356

ABSTRACT

Frequent (>70%) TP53 mutations often promote its protein stabilization, driving esophageal adenocarcinoma (EAC) development linked to poor survival and therapy resistance. We previously reported that during Barrett's (BE) progression to EAC, an isoform switch occurs in the E3 ubiquitin ligase RNF128 (aka GRAIL - gene related to anergy in lymphocytes), enriching isoform 1 (hereby GRAIL1) and, stabilizing the mutant p53 protein. Consequently, GRAIL1 knockdown degrades mutant p53. But how GRAIL1 stabilizes the mutant p53 protein remains unclear. In search for a mechanism, here we performed biochemical and cell biology studies to identify that GRAIL has a binding domain (315-PMCKCDILKA-325) for Hsp40/DNAJ. This interaction can influence DNAJ chaperone activity to modulate misfolded mutant p53 stability. As predicted, either the overexpression of a GRAIL fragment (Frag-J) encompassing the DNAJ binding domain, or a cell permeable peptide (Pep-J) encoding the above 10 amino acids, can bind and inhibit DNAJ-Hsp70 co-chaperone activity thus degrading misfolded mutant p53. Consequently, either Frag-J or Pep-J can reduce the survival of mutant p53 containing dysplastic BE and EAC cells and inhibit growth of patient-derived dysplastic BE organoids (PDOs) in 3D cultures. The misfolded mutant p53 targeting and growth inhibitory effects of Pep-J is comparable to simvastatin, a cholesterol lowering drug, that can degrade misfolded mutant p53 also via inhibiting DNAJA1, although by a distinct mechanism. Implications: We identified a novel ubiquitin ligase independent, chaperone regulating domain in GRAIL and further synthesized a first-in-class novel misfolded mutant p53 degrading peptide having future translational potential.

2.
Placenta ; 154: 168-175, 2024 Jul 14.
Article in English | MEDLINE | ID: mdl-39018609

ABSTRACT

INTRODUCTION: Our goal was to evaluate the potential utility of magnetic resonance imaging (MRI) placental volume as an assessment of placental insufficiency. METHODS: Secondary analysis of a prospective cohort undergoing serial placental MRIs at two academic tertiary care centers. The population included 316 participants undergoing MRI up to three times throughout gestation. MRI was used to calculate placental volume in milliliters (ml). Placental-mediated adverse pregnancy outcome (cAPO) included preeclampsia with severe features, abnormal antenatal surveillance, and perinatal mortality. Serial measurements were grouped as time point 1 (TP1) <22 weeks, TP2 22 0/7-29 6/7 weeks, and TP3 ≥30 weeks. Mixed effects models compared change in placental volume across gestation between cAPO groups. Association between cAPO and placental volume was determined using logistic regression at each TP with discrimination evaluated using area under receiver operator curve (AUC). Placental volume was then added to known clinical predictive variables and evaluated with test characteristics and calibration. RESULTS: 59 (18.7 %) of 316 participants developed cAPO. Placental volume growth across gestation was slower in the cAPO group (p < 0.001). Placental volume was lower in the cAPO group at all time points, and alone was moderately predictive of cAPO at TP3 (AUC 0.756). Adding placental volume to clinical variables had moderate discrimination at all time points, with strongest test characteristics at TP3 (AUC 0.792) with sensitivity of 77.5 % and specificity of 75.3 % at a predicted probability cutoff of 15 %. DISCUSSION: MRI placental volume warrants further study for assessment of placental insufficiency, particularly later in gestation.

3.
Glob Chang Biol ; 30(7): e17419, 2024 Jul.
Article in English | MEDLINE | ID: mdl-39023004

ABSTRACT

Antibiotic resistance genes (ARGs) have moved into focus as a critically important response variable in global change biology, given the increasing environmental and human health threat posed by these genes. However, we propose that elevated levels of ARGs should also be considered a factor of global change, not just a response. We provide evidence that elevated levels of ARGs are a global change factor, since this phenomenon is linked to human activity, occurs globally, and affects biota. We explain why ARGs could be considered the global change factor, rather than the organisms containing them; and we highlight the difference between ARGs and the presence of antibiotics, which are not necessarily linked since elevated levels of ARGs are caused by multiple factors. Importantly, shifting the perspective to elevated levels of ARGs as a factor of global change opens new avenues of research, where ARGs can be the experimental treatment. This includes asking questions about how elevated ARG levels interact with other global change factors, or how ARGs influence ecosystem processes, biodiversity or trophic relationships. Global change biology stands to profit from this new framing in terms of capturing more completely the real extent of human impacts on this planet.


Subject(s)
Drug Resistance, Microbial , Humans , Drug Resistance, Microbial/genetics , Anti-Bacterial Agents/pharmacology , Climate Change , Ecosystem , Human Activities
4.
Environ Microbiol ; 26(7): e16673, 2024 Jul.
Article in English | MEDLINE | ID: mdl-39001572

ABSTRACT

Protists, a crucial part of the soil food web, are increasingly acknowledged as significant influencers of nutrient cycling and plant performance in farmlands. While topographical and climatic factors are often considered to drive microbial communities on a continental scale, higher trophic levels like heterotrophic protists also rely on their food sources. In this context, bacterivores have received more attention than fungivores. Our study explored the connection between the community composition of protists (specifically Rhizaria and Cercozoa) and fungi across 156 cereal fields in Europe, spanning a latitudinal gradient of 3000 km. We employed a machine-learning approach to measure the significance of fungal communities in comparison to bacterial communities, soil abiotic factors, and climate as determinants of the Cercozoa community composition. Our findings indicate that climatic variables and fungal communities are the primary drivers of cercozoan communities, accounting for 70% of their community composition. Structural equation modelling (SEM) unveiled indirect climatic effects on the cercozoan communities through a change in the composition of the fungal communities. Our data also imply that fungivory might be more prevalent among protists than generally believed. This study uncovers a hidden facet of the soil food web, suggesting that the benefits of microbial diversity could be more effectively integrated into sustainable agriculture practices.


Subject(s)
Edible Grain , Fungi , Soil Microbiology , Fungi/classification , Fungi/genetics , Fungi/isolation & purification , Europe , Edible Grain/microbiology , Soil/chemistry , Cercozoa , Bacteria/classification , Bacteria/genetics , Bacteria/isolation & purification , Food Chain , Microbiota , Biodiversity , Mycobiome , Agriculture
5.
Nat Commun ; 15(1): 5866, 2024 Jul 12.
Article in English | MEDLINE | ID: mdl-38997249

ABSTRACT

The estuarine plastisphere, a novel ecological habitat in the Anthropocene, has garnered global concerns. Recent geochemical evidence has pointed out its potential role in influencing nitrogen biogeochemistry. However, the biogeochemical significance of the plastisphere and its mechanisms regulating nitrogen cycling remain elusive. Using 15N- and 13C-labelling coupled with metagenomics and metatranscriptomics, here we unveil that the plastisphere likely acts as an underappreciated nitrifying niche in estuarine ecosystems, exhibiting a 0.9 ~ 12-fold higher activity of bacteria-mediated nitrification compared to surrounding seawater and other biofilms (stone, wood and glass biofilms). The shift of active nitrifiers from O2-sensitive nitrifiers in the seawater to nitrifiers with versatile metabolisms in the plastisphere, combined with the potential interspecific cooperation of nitrifying substrate exchange observed among the plastisphere nitrifiers, collectively results in the unique nitrifying niche. Our findings highlight the plastisphere as an emerging nitrifying niche in estuarine environment, and deepen the mechanistic understanding of its contribution to marine biogeochemistry.


Subject(s)
Bacteria , Biofilms , Estuaries , Nitrification , Seawater , Seawater/microbiology , Bacteria/metabolism , Bacteria/genetics , Biofilms/growth & development , Ecosystem , Microbiota/physiology , Metagenomics , Phylogeny , Nitrogen Cycle , Nitrogen/metabolism , Nitrogen Isotopes/metabolism
6.
Glob Chang Biol ; 30(7): e17415, 2024 Jul.
Article in English | MEDLINE | ID: mdl-39005227

ABSTRACT

Microplastic (MP) pollution likely affects global soil carbon (C) dynamics, yet it remains uncertain how and to what extent MP influences soil respiration. Here, we report on a global meta-analysis to determine the effects of MP pollution on the soil microbiome and CO2 emission. We found that MP pollution significantly increased the contents of soil organic C (SOC) (21%) and dissolved organic C (DOC) (12%), the activity of fluorescein diacetate hydrolase (FDAse) (10%), and microbial biomass (17%), but led to a decrease in microbial diversity (3%). In particular, increases in soil C components and microbial biomass further promote CO2 emission (25%) from soil, but with a much higher effect of MPs on these emissions than on soil C components and microbial biomass. The effect could be attributed to the opposite effects of MPs on microbial biomass vs. diversity, as soil MP accumulation recruited some functionally important bacteria and provided additional C substrates for specific heterotrophic microorganisms, while inhibiting the growth of autotrophic taxa (e.g., Chloroflexi, Cyanobacteria). This study reveals that MP pollution can increase soil CO2 emission by causing shifts in the soil microbiome. These results underscore the potential importance of plastic pollution for terrestrial C fluxes, and thus climate feedbacks.


Subject(s)
Microplastics , Soil Microbiology , Microplastics/analysis , Soil/chemistry , Carbon Dioxide/analysis , Carbon Dioxide/metabolism , Soil Pollutants/analysis , Microbiota/drug effects , Biomass , Carbon/analysis , Carbon/metabolism
7.
Article in English | MEDLINE | ID: mdl-38967777

ABSTRACT

BACKGROUND: In recent years, the indication for cementless short stem total hip arthroplasty (THA) has been widened to elderly patients as they might profit by the advantages of the short-curved implant design as well. Therefore, this study was conducted to evaluate the clinical and radiological outcome of a cementless short stem in elderly patients (≥ 75 years) compared to a young control group (≤ 60 years). METHODS: A retrospective cohort of 316 THAs performed between 2014 and 2017 was prospectively examined. In all patients a cementless, curved short stem and press-fit cup (Fitmore® stem; Allofit®/-S cup; both ZimmerBiomet, Warsaw, IN, USA) were implanted via a minimally-invasive anterolateral approach. Clinical and radiological outcome as well as rate of complications and revision were assessed. RESULTS: In total, 292 patients have been included for analysis of complications and revisions (Øfollow-up: 4.5 years) and 208 patients for clinical and radiological outcome (Øfollow-up: 4.4 years). Complication rate was significantly increased in elderly patients (13.7% vs. 5.8%, p = 0.023), while the revision rate was increased without statistical significance (5.2% vs. 2.2%, p = 0.169). Periprosthetic fractures occurred significantly higher in the elderly patients (5.2% vs. 0.7%; p = 0.026). Both groups showed a comparable clinical outcome in the Harris Hip Score (93.7 vs. 91.9; p = 0.224), Oxford Hip Score (44.5 vs. 43.7; p = 0.350), Forgotten Joint Score (81.7 vs. 81.5; p = 0.952) and WOMAC (7.4 vs. 9.3; p = 0.334). CONCLUSION: Cementless short stem total hip arthroplasty shows a comparable clinical and radiological outcome in patients over 75 years of age compared to younger patients under 60 years of age. However, cementless shorts stem THA shows an increased rate of overall complications and periprosthetic fractures in elderly patients over 75 years of age. Cemented fixation of the femoral component should be considered in patients over 75 years of age. LEVEL OF EVIDENCE: III Case-controlled study. TRIAL REGISTRATION: Observational study without need for trial registration due to ICMJE criteria.

8.
Pediatr Pulmonol ; 2024 Jul 03.
Article in English | MEDLINE | ID: mdl-38958257

ABSTRACT

INTRODUCTION: Preterm infants close to viability commonly require mechanical ventilation (MV) for respiratory distress syndrome. Despite commonly used lung-sparing ventilation techniques, rapid lung expansion during MV induces lung injury, a risk factor for bronchopulmonary dysplasia. This study investigates whether ventilation with optimized lung expansion is feasible and whether it can further minimize lung injury. Therefore, optimized lung expansion ventilation (OLEV) was compared to conventional volume targeted ventilation. METHODS: Twenty preterm lambs were surgically delivered after 132 days of gestation. Nine animals were randomized to receive OLEV for 24 h, and seven received standard MV. Four unventilated animals served as controls (NV). Lungs were sampled for histological analysis at the end of the experimental period. RESULTS: Ventilation with OLEV was feasible, resulting in a significantly higher mean ventilation pressure (0.7-1.3 mbar). Temporary differences in oxygenation between OLEV and MV did not reach clinically relevant levels. Ventilation in general tended to result in higher lung injury scores compared to NV, without differences between OLEV and MV. While pro-inflammatory tumor necrosis factor-α messenger RNA (mRNA) levels increased in both ventilation groups compared to NV, only animals in the MV group showed a higher number of CD45-positive cells in the lung. In contrast, mean (standard deviations) surfactant protein-B mRNA levels were significantly lower in OLEV, 0.63 (0.38) compared to NV 1.03 (0.32) (p = .023, one-way analysis of variance). CONCLUSION: In conclusion, a small reduction in pulmonary inflammation after 24 h of support with OLEV suggests potential to reduce preterm lung injury.

9.
Glob Chang Biol ; 30(7): e17409, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38978455

ABSTRACT

Although positive effects of arbuscular mycorrhizal (AM) fungi on plant performance under drought have been well documented, how AM fungi regulate soil functions and multifunctionality requires further investigation. In this study, we first performed a meta-analysis to test the potential role of AM fungi in maintaining soil functions under drought. Then, we conducted a greenhouse experiment, using a pair of hyphal ingrowth cores to spatially separate the growth of AM fungal hyphae and plant roots, to further investigate the effects of AM fungi on soil multifunctionality and its resistance against drought. Our meta-analysis showed that AM fungi promote multiple soil functions, including soil aggregation, microbial biomass and activities of soil enzymes related to nutrient cycling. The greenhouse experiment further demonstrated that AM fungi attenuate the negative impact of drought on these soil functions and thus multifunctionality, therefore, increasing their resistance against drought. Moreover, this buffering effect of AM fungi persists across different frequencies of water supply and plant species. These findings highlight the unique role of AM fungi in maintaining multiple soil functions by mitigating the negative impact of drought. Our study highlights the importance of AM fungi as a nature-based solution to sustaining multiple soil functions in a world where drought events are intensifying.


Subject(s)
Droughts , Mycorrhizae , Soil Microbiology , Soil , Mycorrhizae/physiology , Soil/chemistry , Plant Roots/microbiology , Plant Roots/growth & development , Biomass
10.
bioRxiv ; 2024 May 30.
Article in English | MEDLINE | ID: mdl-38853840

ABSTRACT

Cardiomyocytes require the HSP70 chaperone BiP to maintain proteostasis in the endoplasmic reticulum (ER) following cardiac stress. The adenylyl transferase (AMPylase) FICD is increasingly recognized to regulate BiP activity through the post-translational addition of an adenosine monophosphate moiety to BiP surface residues. However, the physiological impact of FICD-mediated BiP regulation in the context of cardiovascular health is unknown. Here, we find that FICD deficiency prevents pressure overload-associated heart failure, hypertrophy, and fibrosis, and that FICD knockout mice maintain normal cardiac function after cardiac pressure overload. At a cellular level, we observe that FICD-mediated BiP AMPylation blunts the induction of the unfolded protein response (UPR ER ) and impairs BiP interaction with FAM134B, an ER-phagy receptor, thus limiting ER-phagy induction under stress. In contrast, FICD loss significantly increases BiP-dependent UPR ER induction and ER-phagy in stressed cardiomyocytes. We also uncover cell type-specific consequences of FICD activity in response to ER stress, positioning FICD as a critical proteostasis regulator in cardiac tissue. Our results highlight a novel regulatory paradigm controlling stress resilience in cardiomyocytes and offer a rationale to consider FICD as a therapeutic target to treat cardiac hypertrophy.

11.
Sci Rep ; 14(1): 12688, 2024 06 03.
Article in English | MEDLINE | ID: mdl-38830987

ABSTRACT

Comprehensive characterization of protein networks in mounted brain tissue represents a major challenge in brain and neurodegenerative disease research. In this study, we develop a simple staining method, called TSWIFT, to iteratively stain pre-mounted formalin fixed, paraffin embedded (FFPE) brain sections, thus enabling high-dimensional sample phenotyping. We show that TSWIFT conserves tissue architecture and allows for relabeling a single mounted FFPE sample more than 10 times, even after prolonged storage at 4 °C. Our results establish TSWIFT as an efficient method to obtain integrated high-dimensional knowledge of cellular proteomes by analyzing mounted FFPE human brain tissue.


Subject(s)
Brain , Paraffin Embedding , Staining and Labeling , Humans , Brain/metabolism , Paraffin Embedding/methods , Staining and Labeling/methods , Tissue Fixation/methods , Proteome/analysis , Formaldehyde/chemistry , Proteomics/methods
12.
Glob Chang Biol ; 30(6): e17361, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38822568

ABSTRACT

Our current planetary crisis, including multiple jointly acting factors of global change, moves the need for effective ecosystem restoration center stage and compels us to explore unusual options. We here propose exploring combinatorial approaches to restoration practices: management practices are drawn at random and combined from a locally relevant pool of possible management interventions, thus creating an experimental gradient in the number of interventions. This will move the current degree of interventions to higher dimensionality, opening new opportunities for unlocking unknown synergistic effects. Thus, the high dimensionality of global change (multiple jointly acting factors) would be more effectively countered by similar high-dimensionality in solutions. In this concept, regional restoration hubs play an important role as guardians of locally relevant information and sites of experimental exploration. Data collected from such studies could feed into a global database, which could be used to learn about general principles of combined restoration practices, helping to refine future experiments. Such combinatorial approaches to exploring restoration intervention options may be our best hope yet to achieve decisive progress in ecological restoration at the timescale needed to mitigate and reverse the most severe losses caused by global environmental change.


Subject(s)
Conservation of Natural Resources , Ecosystem , Conservation of Natural Resources/methods , Environmental Restoration and Remediation/methods , Ecology/methods , Climate Change
13.
Nano Lett ; 24(20): 6031-6037, 2024 May 22.
Article in English | MEDLINE | ID: mdl-38717626

ABSTRACT

Manipulating the polarization of light at the nanoscale is key to the development of next-generation optoelectronic devices. This is typically done via waveplates using optically anisotropic crystals, with thicknesses on the order of the wavelength. Here, using a novel ultrafast electron-beam-based technique sensitive to transient near fields at THz frequencies, we observe a giant anisotropy in the linear optical response in the semimetal WTe2 and demonstrate that one can tune the THz polarization using a 50 nm thick film, acting as a broadband wave plate with thickness 3 orders of magnitude smaller than the wavelength. The observed circular deflections of the electron beam are consistent with simulations tracking the trajectory of the electron beam in the near field of the THz pulse. This finding offers a promising approach to enable atomically thin THz polarization control using anisotropic semimetals and defines new approaches for characterizing THz near-field optical response at far-subwavelength length scales.

14.
Article in English | MEDLINE | ID: mdl-38583103

ABSTRACT

PURPOSE: This study aims to examine time trends in the ability to correctly identify schizophrenia and major depression within the German general population from 1990 to 2020, as an indicator of changing mental health literacy (MHL). Additionally, we investigated shifts in the use of stigmatizing language. METHODS: Our analysis is based on four waves of representative population surveys in Germany in 1990/1993 (West Germany: N = 2044, East Germany: N = 1563), 2001 (N = 5025), 2011 (N = 2455), and 2020 (N = 3042) using identical methodology. Respondents were presented with an unlabelled case vignette describing a person who exhibited symptoms of either schizophrenia or major depression. Participants were then asked to name the problem described in the vignette using an open-ended question. RESULTS: From 1990/1993 to 2020, correct identification of schizophrenia increased from 18% to 34% and from 27% to 46% for major depression. However, derogatory labels remained constant throughout all survey waves, particularly for schizophrenia (19% in 1990/1993 and 18% in 2020). For depression, more trivializing and potentially devaluing statements were recorded. CONCLUSION: Despite the increasing use of psychiatric terminology among the general population, the persistence of derogatory labels suggests that improved MHL, reflected in higher recognition rates, may not automatically translate into a reduction in stigmatizing language. With depression, a normalization and trivialization of a severe illness could pose new challenges to people with major depression. Dedicated efforts to combat the stigma of severe mental illness are still needed.

15.
Regen Ther ; 27: 207-217, 2024 Dec.
Article in English | MEDLINE | ID: mdl-38576851

ABSTRACT

Background: Perinatal inflammation increases the risk for bronchopulmonary dysplasia in preterm neonates, but the underlying pathophysiological mechanisms remain largely unknown. Given their anti-inflammatory and regenerative capacity, multipotent adult progenitor cells (MAPC) are a promising cell-based therapy to prevent and/or treat the negative pulmonary consequences of perinatal inflammation in the preterm neonate. Therefore, the pathophysiology underlying adverse preterm lung outcomes following perinatal inflammation and pulmonary benefits of MAPC treatment at the interface of prenatal inflammatory and postnatal ventilation exposures were elucidated. Methods: Instrumented ovine fetuses were exposed to intra-amniotic lipopolysaccharide (LPS 5 mg) at 125 days gestation to induce adverse systemic and peripheral organ outcomes. MAPC (10 × 106 cells) or saline were administered intravenously two days post LPS exposure. Fetuses were delivered preterm five days post MAPC treatment and either killed humanely immediately or mechanically ventilated for 72 h. Results: Antenatal LPS exposure resulted in inflammation and decreased alveolar maturation in the preterm lung. Additionally, LPS-exposed ventilated lambs showed continued pulmonary inflammation and cell junction loss accompanied by pulmonary edema, ultimately resulting in higher oxygen demand. MAPC therapy modulated lung inflammation, prevented loss of epithelial and endothelial barriers and improved lung maturation in utero. These MAPC-driven improvements remained evident postnatally, and prevented concomitant pulmonary edema and functional loss. Conclusion: In conclusion, prenatal inflammation sensitizes the underdeveloped preterm lung to subsequent postnatal inflammation, resulting in injury, disturbed development and functional impairment. MAPC therapy partially prevents these changes and is therefore a promising approach for preterm infants to prevent adverse pulmonary outcomes.

16.
Article in English | MEDLINE | ID: mdl-38607387

ABSTRACT

PURPOSE: Cochlear implantation is a standard approach to hearing rehabilitation and encompasses three main stages: appropriate patient selection, a challenging surgical procedure, which should be as atraumatic as possible and preserve cochlear structures, and lifelong postoperative follow-up. Computed tomography (CT) is performed to assess postoperative implant position. The Siemens Advanced Radar Target Identification System (ARTIS) Pheno provides fluoroscopic imaging during surgery and has so far been mainly used by cardiologists, neurosurgeons and trauma surgeons. METHODS: Six patients with difficult anatomy or a challenging medical history were selected for a surgical procedure, during which we planned to use the ARTIS Pheno to accurately position and assess implant position under fluoroscopy during and immediately after surgery. In all six cases, the ARTIS Pheno was used directly in the surgical setting. The procedures were performed in cooperation with the neuroradiology department in an interdisciplinary manner. RESULTS: In all six patients, fluoroscopy was used to visualise the procedure at different stages of surgery. In five patients, the procedure was successfully completed. This approach allowed us to finally assess implant position and confirm the correct and complete insertion of the electrode while the patient was still under anaesthesia. CONCLUSION: These cases showed positive surgical outcomes. Although the procedure is more complex than a standard approach, patients can be managed in a safe, effective and appropriate manner. The assessment of implant position in real time during surgery leads to greater patient and surgeon satisfaction. The approach presented here ensures a high quality of cochlear implant surgery even in difficult surgical situations and meets the requirements of modern surgery.

18.
Int J Mol Sci ; 25(7)2024 Apr 03.
Article in English | MEDLINE | ID: mdl-38612809

ABSTRACT

Chorioamnionitis is a risk factor for necrotizing enterocolitis (NEC). Ureaplasma parvum (UP) is clinically the most isolated microorganism in chorioamnionitis, but its pathogenicity remains debated. Chorioamnionitis is associated with ileal barrier changes, but colonic barrier alterations, including those of the mucus barrier, remain under-investigated, despite their importance in NEC pathophysiology. Therefore, in this study, the hypothesis that antenatal UP exposure disturbs colonic mucus barrier integrity, thereby potentially contributing to NEC pathogenesis, was investigated. In an established ovine chorioamnionitis model, lambs were intra-amniotically exposed to UP or saline for 7 d from 122 to 129 d gestational age. Thereafter, colonic mucus layer thickness and functional integrity, underlying mechanisms, including endoplasmic reticulum (ER) stress and redox status, and cellular morphology by transmission electron microscopy were studied. The clinical significance of the experimental findings was verified by examining colon samples from NEC patients and controls. UP-exposed lambs have a thicker but dysfunctional colonic mucus layer in which bacteria-sized beads reach the intestinal epithelium, indicating undesired bacterial contact with the epithelium. This is paralleled by disturbed goblet cell MUC2 folding, pro-apoptotic ER stress and signs of mitochondrial dysfunction in the colonic epithelium. Importantly, the colonic epithelium from human NEC patients showed comparable mitochondrial aberrations, indicating that NEC-associated intestinal barrier injury already occurs during chorioamnionitis. This study underlines the pathogenic potential of UP during pregnancy; it demonstrates that antenatal UP infection leads to severe colonic mucus barrier deficits, providing a mechanistic link between antenatal infections and postnatal NEC development.


Subject(s)
Chorioamnionitis , Ureaplasma Infections , Pregnancy , Sheep , Animals , Humans , Female , Infant, Newborn , Ureaplasma Infections/complications , Intestines , Causality , Mucus
19.
Struct Dyn ; 11(2): 024311, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38655563

ABSTRACT

We present an experimental demonstration of ultrafast electron diffraction (UED) with THz-driven electron bunch compression and time-stamping that enables UED probes with improved temporal resolution. Through THz-driven longitudinal bunch compression, a compression factor of approximately four is achieved. Moreover, the time-of-arrival jitter between the compressed electron bunch and a pump laser pulse is suppressed by a factor of three. Simultaneously, the THz interaction imparts a transverse spatiotemporal correlation on the electron distribution, which we utilize to further enhance the precision of time-resolved UED measurements. We use this technique to probe single-crystal gold nanofilms and reveal transient oscillations in the THz near fields with a temporal resolution down to 50 fs. These oscillations were previously beyond reach in the absence of THz compression and time-stamping.

20.
Invest Radiol ; 2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38652067

ABSTRACT

OBJECTIVES: Impaired perivascular clearance has been suggested as a contributing factor to the pathogenesis of Alzheimer disease (AD). However, it remains unresolved when the anatomy of the perivascular space (PVS) is altered during AD progression. Therefore, this study investigates the association between PVS volume and AD progression in cognitively unimpaired (CU) individuals, both with and without subjective cognitive decline (SCD), and in those clinically diagnosed with mild cognitive impairment (MCI) or mild AD. MATERIALS AND METHODS: A convolutional neural network was trained using manually corrected, filter-based segmentations (n = 1000) to automatically segment the PVS in the centrum semiovale from interpolated, coronal T2-weighted magnetic resonance imaging scans (n = 894). These scans were sourced from the national German Center for Neurodegenerative Diseases Longitudinal Cognitive Impairment and Dementia Study. Convolutional neural network-based segmentations and those performed by a human rater were compared in terms of segmentation volume, identified PVS clusters, as well as Dice score. The comparison revealed good segmentation quality (Pearson correlation coefficient r = 0.70 with P < 0.0001 for PVS volume, detection rate in cluster analysis = 84.3%, and Dice score = 59.0%). Subsequent multivariate linear regression analysis, adjusted for participants' age, was performed to correlate PVS volume with clinical diagnoses, disease progression, cerebrospinal fluid biomarkers, lifestyle factors, and cognitive function. Cognitive function was assessed using the Mini-Mental State Examination, the Comprehensive Neuropsychological Test Battery, and the Cognitive Subscale of the 13-Item Alzheimer's Disease Assessment Scale. RESULTS: Multivariate analysis, adjusted for age, revealed that participants with AD and MCI, but not those with SCD, had significantly higher PVS volumes compared with CU participants without SCD (P = 0.001 for each group). Furthermore, CU participants who developed incident MCI within 4.5 years after the baseline assessment showed significantly higher PVS volumes at baseline compared with those who did not progress to MCI (P = 0.03). Cognitive function was negatively correlated with PVS volume across all participant groups (P ≤ 0.005 for each). No significant correlation was found between PVS volume and any of the following parameters: cerebrospinal fluid biomarkers, sleep quality, body mass index, nicotine consumption, or alcohol abuse. CONCLUSIONS: The very early changes of PVS volume may suggest that alterations in PVS function are involved in the pathophysiology of AD. Overall, the volumetric assessment of centrum semiovale PVS represents a very early imaging biomarker for AD.

SELECTION OF CITATIONS
SEARCH DETAIL