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1.
MMWR Morb Mortal Wkly Rep ; 73(40): 903-905, 2024 Oct 10.
Article in English | MEDLINE | ID: mdl-39388389

ABSTRACT

The antiviral drug tecovirimat* has been used extensively to treat U.S. mpox cases since the start of a global outbreak in 2022. Mutations in the mpox viral protein target (F13 or VP37) that occur during treatment can result in resistance to tecovirimat† (1,2). CDC and public health partners have conducted genetic surveillance of monkeypox virus (MPXV) for F13 mutations through sequencing and monitoring of public databases. MPXV F13 mutations associated with resistance have been reported since 2022, typically among severely immunocompromised mpox patients who required prolonged courses of tecovirimat (3-5). A majority of patients with infections caused by MPXV with resistant mutations had a history of tecovirimat treatment; however, spread of tecovirimat-resistant MPXV was reported in California during late 2022 to early 2023 among persons with no previous tecovirimat treatment (3). This report describes a second, unrelated cluster of tecovirimat-resistant MPXV among 18 persons with no previous history of tecovirimat treatment in multiple states.


Subject(s)
Antiviral Agents , Disease Outbreaks , Drug Resistance, Viral , Monkeypox virus , Mpox (monkeypox) , Humans , United States/epidemiology , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Mpox (monkeypox)/epidemiology , Mpox (monkeypox)/drug therapy , Monkeypox virus/isolation & purification , Monkeypox virus/genetics , Monkeypox virus/drug effects , Adult , Male , Female , Middle Aged , Adolescent , Young Adult , Aged , Child , Mutation , Dibenzothiepins , Benzamides/therapeutic use , Benzamides/pharmacology , Phthalimides
3.
Ecol Lett ; 27(9): e14524, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39354899

ABSTRACT

Widely documented in animals, behavioural thermoregulation mitigates negative impacts of climate change. Plants experience especially strong thermal variability but evidence for plant behavioural thermoregulation is limited. Along a montane elevation gradient, Argentina anserina flowers warm more in alpine populations than at lower elevation. We linked floral temperature with phenotypes to identify warming mechanisms and documented petal movement and pollinator visitation using time-lapse cameras. High elevation flowers were more cupped, focused light deeper within flowers and were more responsive to air temperature than low; cupping when cold and flattening when warm. At high elevation, a 20° increase in petal angle resulted in a 0.46°C increase in warming. Warming increased pollinator visitation, especially under cooler high elevation temperatures. A plasticity study revealed constitutive elevational differences in petal cupping and stronger temperature-induced floral plasticity in high elevation populations. Thus, plant populations have evolved different behavioural responses to temperature driving differences in thermoregulatory capacity.


Subject(s)
Flowers , Pollination , Flowers/physiology , Argentina , Animals , Temperature , Altitude , Climate Change , Body Temperature Regulation/physiology
4.
Laryngoscope ; 2024 Oct 02.
Article in English | MEDLINE | ID: mdl-39354901

ABSTRACT

BACKGROUND: Laryngeal dystonia (LD) is an isolated focal dystonia characterized by involuntary spasms in laryngeal muscles selectively impairing speech production. Anecdotal observations reported the worsening of LD symptoms in stressful or vocally demanding situations. OBJECTIVES: To examine the impact of surrounding audio-visual complexity on LD symptomatology for a better understanding of disorder phenomenology. METHODS: We developed well-controlled virtual reality (VR) environments of real-life interpersonal communications to investigate how different levels of audio-visual complexity may impact LD symptoms. The VR experiments were conducted over five consecutive days, during which each patient experienced 10 h of 4100 experimental trials in VR with gradually increasing audio-visual complexity. Daily reports were collected about patients' voice changes, as well as their comfort, engagement, concentration, and drowsiness from using VR technology. RESULTS: After a weekly VR exposure, 82% of patients reported changes in their voice symptoms related to changes in background audio-visual complexity. Significant differences in voice symptoms were found between the first two levels of the audio-visual challenge complexity independent of study sessions or VR environments. CONCLUSION: This study demonstrated that LD symptoms are impacted by audio-visual background across various virtual realistic settings. These findings should be taken into consideration when planning behavioral experiments or evaluating the outcomes of clinical trials in these patients. Moreover, these data show that VR presents a reliable and useful technology for providing real-life assessments of the impact of various experimental settings, such as during the testing of novel therapeutic interventions in these patients. LEVEL OF EVIDENCE: Level 3 Laryngoscope, 2024.

5.
STAR Protoc ; 5(4): 103361, 2024 Oct 05.
Article in English | MEDLINE | ID: mdl-39369385

ABSTRACT

Acquired resistance to oncogene-targeted therapies is the major driver of mortality for patients with cancer. Here, we present a 6-to-16-week assay to model the development of acquired resistance in adherent and suspension cancer cell lines. We describe steps for determining therapeutic dose, assaying acquired resistance, and testing combination therapies. This protocol is a high-throughput, cost-effective, and scalable method to model acquired drug resistance to established and newly developed therapies. For complete details on the use and execution of this protocol, please refer to Sealover et al.1 and Theard et al.2.

6.
Biotechnol Bioeng ; 2024 Oct 11.
Article in English | MEDLINE | ID: mdl-39392130

ABSTRACT

Spirulina is the common name for the edible, nonheterocystous, filamentous cyanobacterium Arthrospira platensis that is grown industrially as a food supplement, animal feedstock, and pigment source. Although there are many applications for engineering this organism, until recently no genetic tools or reproducible transformation methods have been published. While recent work showed the production of a diversity of proteins in A. platensis, including single-domain antibodies for oral delivery, there remains a need for a modular, characterized genetic toolkit. Here, we independently establish a reproducible method for the transformation of A. platensis and engineer this bacterium to produce acetaminophen as proof-of-concept for small molecule production in an edible host. This work opens A. platensis to the wider scientific community for future engineering as a functional food for nutritional enhancement, modification of organoleptic traits, and production of pharmaceuticals for oral delivery.

7.
J Biol Chem ; 300(10): 107743, 2024 Sep 01.
Article in English | MEDLINE | ID: mdl-39222680

ABSTRACT

Translation initiation is a highly regulated, multi-step process that is critical for efficient and accurate protein synthesis. In bacteria, initiation begins when mRNA, initiation factors, and a dedicated initiator fMet-tRNAfMet bind the small (30S) ribosomal subunit. Specific binding of fMet-tRNAfMet in the peptidyl (P) site is mediated by the inspection of the fMet moiety by initiation factor IF2 and of three conserved G-C base pairs in the tRNA anticodon stem by the 30S head domain. Tandem A-minor interactions form between 16S ribosomal RNA nucleotides A1339 and G1338 and tRNA base pairs G30-C40 and G29-C41, respectively. Swapping the G30-C40 pair of tRNAfMet with C-G (called tRNAfMet M1) reduces discrimination against the noncanonical start codon CUG in vitro, suggesting crosstalk between the gripping of the anticodon stem and recognition of the start codon. Here, we solved electron cryomicroscopy structures of Escherichia coli 70S initiation complexes containing the fMet-tRNAfMet M1 variant paired to the noncanonical CUG start codon, in the presence or absence of IF2 and the non-hydrolyzable GTP analog GDPCP, alongside structures of 70S initiation complexes containing this tRNAfMet variant paired to the canonical bacterial start codons AUG, GUG, and UUG. We find that the M1 mutation weakens A-minor interactions between tRNAfMet and 16S nucleotides A1339 and G1338, with IF2 strengthening the interaction of G1338 with the tRNA minor groove. These structures suggest how even slight changes to the recognition of the fMet-tRNAfMet anticodon stem by the ribosome can impact the start codon selection.

8.
J Arthroplasty ; 2024 Sep 02.
Article in English | MEDLINE | ID: mdl-39233103

ABSTRACT

BACKGROUND: Socioeconomic disadvantage has been associated with negative outcomes following total hip arthroplasty (THA) and total knee arthroplasty (TKA). The area deprivation index (ADI) and distressed communities index (DCI) are composite rankings that score socioeconomic status (SES) using patients' home addresses. The purpose of this study was to examine the association of ADI and DCI with outcomes following THA and TKA while controlling for potential confounding covariates. METHODS: A series of 4,146 consecutive patients undergoing primary THA and TKA between January 2018 and May 2023 were queried from our institutional total joint registry. The 90-day medical and surgical complications and resource utilization were collected. The ADI and DCI scores were obtained for each patient, and the association between these scores and postoperative outcomes was analyzed. RESULTS: The ADI and DCI were both associated with patient age, sex, race, comorbidity burden, and smoking status. After controlling for these variables, higher ADI and DCI scores were associated with increased length of stay (P = 0.003 and P = 0.008, respectively), but were not associated with the occurrence of any 90-day complication, reoperation, or revision. CONCLUSIONS: The SES, as quantified by ADI and DCI, was associated with multiple known risk factors for complications following THA and TKA, but was not independently associated with complications, reoperations, or revision surgeries at 90 days postoperatively. While convenient metrics for the quantification of SES, in some populations, ADI and DCI may not be independently associated with detrimental outcomes following THA and TKA.

9.
Med Oncol ; 41(10): 240, 2024 Sep 05.
Article in English | MEDLINE | ID: mdl-39231878

ABSTRACT

Interleukin-22, discovered in the year of 2000, is a pleiotropic Th17 cytokine from the IL-10 family of cytokines. IL-22 signals through the type 2 cytokine receptor complex IL-22R and predominantly activates STAT3. This pathway leads to the transcription of several different types of genes, giving IL-22 context-specific functions ranging from inducing antimicrobial peptide expression to target cell proliferation. In recent years, it has been shown that IL-22 is involved in the pathogenesis of neoplasia in some cancers through its pro-proliferative and anti-apoptotic effects. This review highlights studies with recent discoveries and conclusions drawn on IL-22 and its involvement and function in various cancers. Such a study may be helpful to better understand the role of IL-22 in cancer so that new treatment could be developed targeting IL-22.


Subject(s)
Interleukin-22 , Interleukins , Neoplasms , Humans , Interleukins/metabolism , Neoplasms/metabolism , Neoplasms/immunology , Neoplasms/pathology , Animals , Signal Transduction , STAT3 Transcription Factor/metabolism , Receptors, Interleukin/metabolism , Receptors, Interleukin/genetics
10.
Sci Transl Med ; 16(766): eadn1285, 2024 Sep 25.
Article in English | MEDLINE | ID: mdl-39321266

ABSTRACT

Acute myeloid leukemia (AML) is a devastating disease initiated and maintained by a rare subset of cells called leukemia stem cells (LSCs). LSCs are responsible for driving disease relapse, making the development of new therapeutic strategies to target LSCs urgently needed. The use of mass spectrometry-based metabolomics profiling has enabled the discovery of unique and targetable metabolic properties in LSCs. However, we do not have a comprehensive understanding of metabolite differences between LSCs and their normal counterparts, hematopoietic stem and progenitor cells (HSPCs). In this study, we used an unbiased mass spectrometry-based metabolomics analysis to define differences in metabolites between primary human LSCs and HSPCs, which revealed that LSCs have a distinct metabolome. Spermidine was the most enriched metabolite in LSCs compared with HSPCs. Pharmacological reduction of spermidine concentrations decreased LSC function but spared normal HSPCs. Polyamine depletion also decreased leukemic burden in patient-derived xenografts. Mechanistically, spermidine depletion induced LSC myeloid differentiation by decreasing eIF5A-dependent protein synthesis, resulting in reduced expression of a select subset of proteins. KAT7, a histone acetyltransferase, was one of the top candidates identified to be down-regulated by spermidine depletion. Overexpression of KAT7 partially rescued polyamine depletion-induced decreased colony-forming ability, demonstrating that loss of KAT7 is an essential part of the mechanism by which spermidine depletion targets AML clonogenic potential. Together, we identified and mechanistically dissected a metabolic vulnerability of LSCs that has the potential to be rapidly translated into clinical trials to improve outcomes for patients with AML.


Subject(s)
Leukemia, Myeloid, Acute , Neoplastic Stem Cells , Spermidine , Animals , Humans , Mice , Acetyltransferases , Cell Differentiation , Disease Models, Animal , Hematopoietic Stem Cells/metabolism , Leukemia, Myeloid, Acute/metabolism , Leukemia, Myeloid, Acute/pathology , Metabolome , Metabolomics , Neoplastic Stem Cells/metabolism , Neoplastic Stem Cells/pathology , Spermidine/metabolism
11.
Article in English | MEDLINE | ID: mdl-39330924

ABSTRACT

BACKGROUND: Palpation of anatomic landmarks is difficult in patients with obesity, which could increase difficulty of achieving femoral access and resuscitative endovascular balloon occlusion of the aorta (REBOA) placement. The primary aim of this study was to examine the association between obesity and successful REBOA placement. We hypothesized that higher body mass index (BMI) would decrease first-attempt success and increase time to successful aortic occlusion (AO). METHODS: A review of the Aortic Occlusion for Resuscitation in Trauma and Acute Care Surgery (AORTA) registry was performed on patients who underwent REBOA placement with initiation systolic blood pressure >0 mm Hg from years 2013-2022. Patients were excluded if they received cardiopulmonary resuscitation on arrival, underwent open AO, or missing data entries for variables of interest. Body mass index categorization was as follows: non-obese (<30), class I (30-34.9), class II (35-39.9), and class III (40+) obesity. Patients were also stratified by access technique, including use of palpation or ultrasound guidance. RESULTS: Inclusion criteria were met by 410 patients. On binary analysis, no primary outcomes of interest, including rate of success, time to placement, or mortality, were significantly impacted by BMI. Among BMI subgroups, there was no statistical difference in injury severity, admission systolic blood pressure (SBP), or augmented SBP. At initiation of aortic occlusion, patients with class II and class III obesity had higher median SBP compared with non- and class I obese patients (p = 0.03). Body mass index subgroup did not impact likelihood of first-attempt success or conversion to open procedure. When stratified by access technique, there was no difference in success rates, time to success or mortality between groups. CONCLUSION: Body habitus did not impact success of REBOA placement, time to successful AO, or mortality. Further, ultrasound guidance was not superior to landmark palpation for arterial access. Following traumatic injury without hemodynamic collapse, obesity should not deter providers from considering REBOA placement. LEVEL OF EVIDENCE: Therapeutic/Care management, Observational, Cross-sectional; Level IV.

13.
Neurocrit Care ; 2024 Sep 25.
Article in English | MEDLINE | ID: mdl-39322846

ABSTRACT

BACKGROUND: The volume of hemorrhage is a crucial factor in predicting outcomes following aneurysmal subarachnoid hemorrhage (aSAH). Although grading scales such as the Fisher score are widely used, they can lead to inaccuracies in quantifying the total blood volume because of their reliance on visual assessment. We analyzed a large cohort of patients with aSAH with a semiautomated software for the precise quantification of hemorrhage volume. The primary aim is to identify clear thresholds that correlate with the likelihood of complications after aSAH, thereby enhancing the predictive accuracy and improving patient management strategies. METHODS: A semiautomated algorithm was developed to analyze noncontrast computed tomography scans of patients with aSAH. The algorithm categorized tissues into blood, gray matter, white matter, and cerebrospinal fluid, isolating the blood for volume quantification. Receiver operating curve analysis was done to establish thresholds for vasospasm, acute hydrocephalus, shunt-dependent hydrocephalus (SDHC), and death within 7 days. RESULTS: A total of 500 patients with aSAH and their respective aneurysms were analyzed. Hemorrhage volume was significantly higher in patients with vasospasm (21.7 [10.9-41.4] vs. 10.7 [4.2-26.9], p < 0.001), acute hydrocephalus (22.7 [9.2-41.8] vs. 5.1 [2.1-13.5], p < 0.001), SDHC (23.8 [11.3-40.7] vs. 11.7 [4.1-28.2], p < 0.001), and those who died before 7 days (52.8 [34.6-90.6] mL vs. 14.8 [5.0-32.4] mL, p < 0.001) compared with their counterparts. Notably, specific hemorrhage thresholds were identified for each complication: 15.16 mL for vasospasm (65% sensitivity and 60% specificity), 9.95 mL for acute hydrocephalus (74% sensitivity and 69% specificity), 16.76 mL for SDHC (63% sensitivity and 60% specificity), and 33.84 mL for death within 7 days (79% sensitivity and 77% specificity). CONCLUSIONS: Semiautomated blood volume quantification tools could aid in stratifying complication risk after aSAH. Established thresholds for hemorrhage volume related to complications could be used in clinical practice to aid in management decisions.

14.
bioRxiv ; 2024 Jun 09.
Article in English | MEDLINE | ID: mdl-39229016

ABSTRACT

Genome organization is essential for proper function, including gene expression. In metazoan genome organization, chromatin loops and Topologically Associated Domains (TADs) facilitate local gene clustering, while chromosomes form distinct nuclear territories characterized by compartmentalization of silent heterochromatin at the nuclear periphery and active euchromatin in the nucleus center. A similar hierarchical organization occurs in the fungus Neurospora crassa where its seven chromosomes form a Rabl conformation, where heterochromatic centromeres and telomeres independently cluster at the nuclear membrane, while interspersed heterochromatic loci in Neurospora aggregate across megabases of linear genomic distance for forming TAD-like structures. However, the role of individual heterochromatic loci in normal genome organization and function is unknown. Here, we examined the genome organization of a Neurospora strain harboring a ~47.4 kilobase facultative (temporarily silent) heterochromatic region deletion, as well as the genome organization of a strain deleted of a 110.6 kilobase permanently silent constitutive heterochromatic region. While the facultative heterochromatin deletion had little effect on local chromatin structure, the constitutive heterochromatin deletion altered local TAD-like structures, gene expression, and the predicted 3D genome structure by qualitatively repositioning genes into the nucleus center. Our work elucidates the role of individual heterochromatic regions for genome organization and function.

15.
J Chem Theory Comput ; 2024 Sep 10.
Article in English | MEDLINE | ID: mdl-39254204

ABSTRACT

Developing theoretical understanding of complex reactions and processes at interfaces requires using methods that go beyond semilocal density functional theory to accurately describe the interactions between solvent, reactants and substrates. Methods based on many-body perturbation theory, such as the random phase approximation (RPA), have previously been limited due to their computational complexity. However, this is now a surmountable barrier due to the advances in computational power available, in particular through modern GPU-based supercomputers. In this work, we describe the implementation of RPA calculations within BerkeleyGW and show its favorable computational performance on large complex systems relevant for catalysis and electrochemistry applications. Our implementation builds off of the static subspace approximation which, by employing a compressed representation of the frequency dependent polarizability, enables the evaluation of the RPA correlation energy with significant acceleration and systematically controllable accuracy. We find that the computational cost of calculating the RPA correlation energy scales only linearly with system size for systems containing up to 50 thousand bands, and is expected to scale quadratically thereafter. We also show excellent strong scaling results across several supercomputers, demonstrating the performance and portability of this implementation.

16.
Curr Urol ; 18(3): 247-249, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39219630

ABSTRACT

Nephroureterectomy is currently the criterion-standard treatment for high-grade upper tract urothelial carcinoma (UTUC). Current guidelines and expert opinions propose some exceptions to this approach based on patient characteristics, disease status, and function of the contralateral kidney. We present a rare case of a patient with horseshoe kidney, bilateral large nephrolithiasis, high-grade UTUC in one moiety, and relative parenchymal thinning of the contralateral side. The patient was treated with a percutaneous, minimally invasive, nephron sparing approach. The patient also had intracollecting system instillations of gemcitabine and docetaxel. Minimally invasive percutaneous resection of high-grade UTUC is a safe procedure in select cases. Current guidelines may not apply to all patients; unique scenarios with UTUC may require personalized decision-making and treatment at specialized centers.

17.
Neurobiol Aging ; 144: 68-77, 2024 Sep 12.
Article in English | MEDLINE | ID: mdl-39288668

ABSTRACT

While structural and biochemical brain changes are well-documented in ageing, functional neuronal network differences, as indicated by electrophysiological markers, are less clear. Moreover, age-related changes in sustained attention and their associated electrophysiological correlates are still poorly understood. To address this, we analysed cross-sectional baseline electroencephalography (EEG) and cognitive data from the Lifestyle Intervention Study for Dementia Risk Reduction (LEISURE). Participants were 96 healthy older adults, aged 50-84. We examined resting-state EEG periodic (individual alpha frequency [IAF], aperiodic-adjusted individual alpha power [aIAP]) and aperiodic (exponent and offset) activity, and their associations with age and sustained attention. Results showed associations between older age and slower IAF, but not aIAP or global aperiodic exponent and offset. Additionally, hierarchical linear regression revealed that after controlling for demographic variables, faster IAF was associated with better Sustained Attention to Response Task performance, and mediation analysis confirmed IAF as a mediator between age and sustained attention performance. These findings indicate that IAF may be an important marker of ageing, and a slower IAF may signal diminished cognitive processing capacity for sustained attention in older adults.

18.
BMJ Open ; 14(9): e078231, 2024 Sep 12.
Article in English | MEDLINE | ID: mdl-39266308

ABSTRACT

INTRODUCTION: In rheumatoid arthritis (RA), immunosuppressive therapies may achieve symptomatic relief, but do not induce long-term, drug-free remission. Meanwhile, the lifelong use of immunosuppressive drugs confers increased risk for malignancy and infections. As such, there is an unmet need for novel treatments that selectively target the pathogenic immune response in RA by inducing tolerance to autoantigens. Autologous cell therapy using antigen-loaded tolerogenic dendritic cells (tolDCs) aims to reinstate autoantigen-specific immunological tolerance in RA and could potentially meet this need. METHODS AND ANALYSIS: We report here the design of the phase I/II, investigator-initiated, open-label, dose-escalation trial TOLERANT. In this study, we will evaluate the intranodal administration of tolDCs in patients with RA that are in remission under immunosuppressive therapy. The tolDCs in this trial are loaded with the heat shock protein 70-derived peptide mB29a, which is an effective surrogate autoantigen in animal models of arthritis. Within this study, three dose-escalation cohorts (two intranodal injections of 5×106, 10×106 and 15×106 tolDCs), each consisting of three patients, are evaluated to identify the highest safe dose (recommended dose), and an extension cohort of nine patients will be treated with the recommended dose. The (co-)primary endpoints of this study are safety and feasibility, which we assess by the number of AEs and the successful production of tolDCs. The secondary endpoints include the immunological effects of the treatment, which we assess with a variety of high-dimensional and antigen-specific immunological assays. Clinical effects are exploratory outcomes. ETHICS AND DISSEMINATION: Ethical approval for this study has been obtained from the Netherlands Central Committee on Research Involving Human Subjects. The outcomes of the trial will be disseminated through publications in open-access, peer-reviewed scientific journals, scientific conferences and to patient associations. TRIAL REGISTRATION NUMBERS: NCT05251870; 2019-003620-20 (EudraCT); NL71296.000.20 (CCMO register).


Subject(s)
Arthritis, Rheumatoid , Autoantigens , Dendritic Cells , Humans , Arthritis, Rheumatoid/immunology , Arthritis, Rheumatoid/drug therapy , Arthritis, Rheumatoid/therapy , Dendritic Cells/immunology , Autoantigens/immunology , Immune Tolerance , HSP70 Heat-Shock Proteins/immunology , Male , Female , Clinical Trials, Phase I as Topic , Adult , Middle Aged , Clinical Trials, Phase II as Topic , Transplantation, Autologous
19.
Neurobiol Aging ; 144: 93-103, 2024 Sep 17.
Article in English | MEDLINE | ID: mdl-39298870

ABSTRACT

Sustained attention is important for maintaining cognitive function and autonomy during ageing, yet older people often show reductions in this domain. The role of the underlying neurobiology is not yet well understood, with most neuroimaging studies primarily focused on fMRI. Here, we utilise sMRI to investigate the relationships between age, structural brain volumes and sustained attention performance. Eighty-nine healthy older adults (50-84 years, Mage 65.5 (SD=8.4) years, 74 f) underwent MRI brain scanning and completed two sustained attention tasks: a rapid visual information processing (RVP) task and sustained attention to response task (SART). Independent hierarchical linear regressions demonstrated that greater volumes of white matter hyperintensities (WMH) were associated with worse RVP_A' performance, whereas greater grey matter volumes were associated with better RVP_A' performance. Further, greater cerebral white matter volumes were associated with better SART_d' performance. Importantly, mediation analyses revealed that both grey and white matter volumes completely mediated the relationship between ageing and sustained attention. These results explain disparate attentional findings in older adults, highlighting the intervening role of brain structure.

20.
Fluids Barriers CNS ; 21(1): 72, 2024 Sep 16.
Article in English | MEDLINE | ID: mdl-39285434

ABSTRACT

BACKGROUND: Pathways for intravenously administered gadolinium-based-contrast-agents (GBCAs) entering cerebrospinal-fluid (CSF) circulation in the human brain are not well-understood. The blood-CSF-barrier (BCSFB) in choroid-plexus (CP) has long been hypothesized to be a main entry-point for intravenous-GBCAs into CSF. Most existing studies on this topic were performed in animals and human patients with various diseases. Results in healthy human subjects are limited. Besides, most studies were performed using MRI methods with limited temporal resolution and significant partial-volume effects from blood and CSF. METHODS: This study employs the recently developed dynamic-susceptibility-contrast-in-the-CSF (cDSC) MRI approach to measure GBCA-distribution in the CSF immediately and 4 h after intravenous-GBCA administration in healthy subjects. With a temporal resolution of 10 s, cDSC MRI can track GBCA-induced CSF signal changes during the bolus phase, which has not been investigated previously. It employs a long echo-time (TE = 1347 ms) to suppress tissue and blood signals so that pure CSF signal is detected with minimal partial-volume effects. GBCA concentration in the CSF can be estimated from cDSC MRI. In this study, cDSC and FLAIR MRI were performed immediately and 4 h after intravenous GBCA administration in 25 healthy volunteers (age 48.9 ± 19.5 years; 14 females). Paired t-tests were used to compare pre-GBCA and post-GBCA signal changes, and their correlations with age were evaluated using Pearson-correlation-coefficients. RESULTS: At ~ 20 s post-GBCA, GBCA-induced cDSC signal changes were detected in the CSF around CP (ΔS/S = - 2.40 ± 0.30%; P < .001) but not in the rest of lateral ventricle (LV). At 4 h, significant GBCA-induced cDSC signal changes were observed in the entire LV (ΔS/S = - 7.58 ± 3.90%; P = .002). FLAIR MRI showed a similar trend. GBCA-induced CSF signal changes did not correlate with age. CONCLUSIONS: These results provided direct imaging evidence that GBCAs can pass the BCSFB in the CP and enter ventricular CSF immediately after intravenous administration in healthy human brains. Besides, our results in healthy subjects established a basis for clinical studies in brain diseases exploiting GBCA-enhanced MRI to detect BCSFB dysfunction.


Subject(s)
Choroid Plexus , Contrast Media , Magnetic Resonance Imaging , Humans , Contrast Media/administration & dosage , Choroid Plexus/diagnostic imaging , Magnetic Resonance Imaging/methods , Male , Adult , Female , Gadolinium/administration & dosage , Middle Aged , Healthy Volunteers , Young Adult , Administration, Intravenous
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