Deposition of Gadolinium in the Central and Peripheral Nervous Systems and Its Effects on Sensory, Cognitive, and Athletic Implications after Multiple Injections of Gadolinium-Based Contrast Agents in Rats

BACKGROUND AND PURPOSE

After repeat administration of gadolinium-based contrast agents (GBCAs), the association between gadolinium retention in the central and peripheral nervous systems and the main manifestations of myelopathy and progressive neurologic symptoms remains unclear. We investigated the effects of the repeat administration of GBCAs on gadolinium retention in the central and peripheral nervous systems and the sensory, cognitive, and athletic implications.

MATERIALS AND METHODS

Forty-eight male Wistar rats (6 weeks of age) were randomly divided into 4 experimental groups (12 rats in each group): the gadodiamide group (linear and nonionic GBCAs), the gadopentetate dimeglumine group (linear and ionic GBCAs), the gadoterate meglumine group (macrocyclic and ionic GBCAs), and the control group (0.9% saline solution). The brains of the rats were scanned using 9.4T MRI. Sensory behavioral tests were performed to assess the effect of GBCAs on pain sensitivity function. Gadolinium deposition in the brain, spinal cord, and peripheral nerves was determined by inductively coupled plasma mass-spectrometry. Transmission electron microscopy was used to observe the microscopic distribution of gadolinium after deposition in the spinal cord. The histopathologic features in the spinal cord were analyzed by H&E staining, Nissl staining, glial fibrillary acidic protein staining, and neuron-specific enolase staining after administration of GBCAs.

RESULTS

All GBCAs resulted in gadolinium deposition in the central and peripheral nerve tissues, with the highest deposition in the sciatic nerve tissue (mean, 62.86 [SD, 12.56] nmol/g). Decreased muscle power, impairment of spatial cognitive function power, and pain hypersensitivity to thermal and mechanical stimuli were observed after exposure to gadodiamide. At the spinal cord, transmission electron microscopy found that the region of gadolinium depositions had a spheric structure similar to "sea urchins" and was mainly located near the vascular basement membrane.

CONCLUSIONS

Multiple injections of GBCAs caused gadolinium deposition in the brain, spinal cord, and peripheral nerves, especially in the spinal cords of the gadodiamide group. Gadodiamide led to pain hypersensitivity and decreased muscle power and cognitive ability. For the patients who are hypersensitive to pain and need multiple MRI examinations, we recommend using macrocyclic GBCAs and the lowest dose possible.

[Take-home messages from the 2nd COPD 2023 Biennial of the French Society of Respiratory Diseases. Placing the patient at the center of the care pathway]

INTRODUCTION

The second COPD Biennial organized by the COPD working group of the French Society of Respiratory Diseases took place in Paris (Cochin) on 13th December 2023.

STATE OF THE ART

Major trends in 2023 were discussed; they encompassed concepts, definitions, biologics, care pathways, pulmonary rehabilitation and complex situations entailed by respiratory infections, cardiovascular comorbidities and pulmonary hypertension, and modalities of oxygen therapy and ventilation.

PERSPECTIVES

The different talks underlined major changes in COPD including the concepts of pre-COPD, etiotypes, health trajectories and new definitions of exacerbation. Recent results in biologics for COPD open the door to new pharmacological options. Assessment of current care pathways in France highlighted some causes for concern. For example, pulmonary rehabilitation is a key but insufficiently practiced element. Respiratory infections require careful assessment and treatments. Diagnosis and treatment of cardiovascular comorbidities and pulmonary hypertension are of paramount importance. As of late, oxygen therapy and ventilation modalities have evolved, and are beginning to afford more personalized options.

CONCLUSIONS

As regards COPD, a personalized approach is crucial, placing the patient at the center of the care pathway and facilitating coordination between healthcare providers.

Effects of Gadolinium Retention in the Brains of Type 2 Diabetic Rats after Repeated Administration of Gadolinium-Based MRI Contrast Agents on Neurobiology and NLRP3 Inflammasome Activation

BACKGROUND

The neurotoxic potential of gadolinium (Gd)-based contrast agents (GBCAs) retention in the brains of patients with type 2 diabetes mellitus (T2DM) is unclear.

PURPOSE

To determine the deposition and clearance of GBCAs in T2DM rats and the mechanism by which Gd enhances nucleotide-binding oligomerization domain-3 (NLRP3) inflammasome activation.

STUDY TYPE

Cross-sectional, prospective.

ANIMAL MODEL

104 T2DM male Wistar rats.

FIELD STRENGTH/SEQUENCE

9.4-T, T1-weighted fast spin echo sequence.

ASSESSMENT

T2DM (male Wistar rats, n = 52) and control group (healthy, male Wistar rats, n = 52) rats received saline, gadodiamide, Gd-diethylenetriaminepentaacetic acid, and gadoterate meglumine for four consecutive days per week for 7 weeks. The distribution and clearance of Gd in the certain brain were assessed by MRI (T1 signal intensity and relaxation rate R1, on the last day of each week), inductively coupled plasma mass-spectroscopy, ultraperformance liquid chromatography mass spectrometry, and transmission electron microscopy. Behavioral tests, histopathological features, and the effects of GBCAs on neuroinflammation were also analyzed.

STATISTICAL TESTS

One-way analysis of variance, bonferroni method, and unpaired t-test. A P-value <0.05 was considered statistically significant.

RESULTS

The movement distance and appearance time in the open field test of the T2DM rats in the gadodiamide group were significantly shorter than in the other groups. Furthermore, the expression of NLRP3, Pro-Caspase-1, interleukin-1β (IL-1β), and apoptosis-associated speck-like protein containing a CARD protein in neurons was significantly higher in the gadodiamide group than in the saline group, as shown by Western blot. Gadodiamide also induced differentiation of microglia into M1 type, decreased the neuronal mitochondrial membrane potential, and significantly increased neuronal apoptosis from flow cytometry.

DATA CONCLUSION

T2DM may affect both the deposition and clearance of GBCAs in the brain. Informed by the T2DM model, gadodiamide could mediate the neuroinflammatory response by NLRP3 inflammasome activation.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY: Stage 1.

Impact of Free Hospital-Provided Rideshare Service on Radiation Therapy Completion Rates: A Matched Cohort Analysis

PURPOSE/OBJECTIVE(S)

Radiation therapy (RT) is generally given in consecutive daily sessions over multiple weeks. This poses challenges for patients who face barriers such as limited access to public or private transportation, limited financial resources, lack of social support, and long distances to healthcare facilities. Delayed or incomplete RT increases risk for worse clinical outcomes. The potential of rideshare service, which uses a private vehicle for hire arranged through a phone-based application or website, to facilitate timely RT is understudied.

MATERIALS/METHODS

Retrospective data was collected on patients who received RT at a single institution from 2017-2022. Patient demographic and treatment characteristics were compared between those who did and did not utilize free hospital-provided rideshare service. RT completion rates were analyzed for a 1:1 matched non-rideshare cohort using optimal matching with the scaled Euclidean distance metric, to balance age, sex, race, performance status, number of fractions prescribed, Area Deprivation Index (ADI), distance to treatment center, year of diagnosis, treatment site, intent, and modality. ADI is a validated composite measure of community-level socioeconomic deprivation.

RESULTS

Of 2,906 patients who underwent RT, 58 utilized free hospital-provided rideshare service. Rideshare utilizers had a lower median age (60 vs 66, p = .02), and were more likely to identify as Black or African American (60 vs 22%, p<.0001) compared to non-rideshare utilizers. Rideshare utilizers also had higher ADI scores (median 9 vs 5, p<.0001), indicating higher socioeconomic disadvantage, and travelled shorter distances for treatment (median 5.0 vs 14.7 miles, p<.0001). More rideshare utilizers underwent RT for curative intent (79 vs 50%, p<.0001), concordant with a higher number of fractions prescribed (median 28 vs 5, p<.0001) as well as longer treatment course duration (median 39 vs 13 days, p<.0001). The most common treatment sites were head and neck (31%) and breast / chest wall (22%) for rideshare utilizers, and pelvis (27%) and brain (21%) for non-rideshare utilizers (p<.0001). Volumetric modulated arc therapy followed by 3D conformal were the most common treatment modalities in both groups. The matched cohort analysis revealed that RT completion rates were significantly higher for rideshare vs non-rideshare utilizers at 96 vs 81% (p = .01) overall, and 98 vs 78% (p = .01) for patients undergoing treatment with curative intent.

CONCLUSION

Even after adjustment for socioeconomic, clinical, and treatment characteristics, utilization of free hospital-provided rideshare service was associated with improved RT completion rates. These findings are notable as the majority of rideshare utilizers come from socioeconomically marginalized communities, and would otherwise be expected to face significant barriers to RT completion.

Sphingomonas caeni sp. nov., a phenolic acid-degrading bacterium isolated from activated sludge

A Gram-stain-negative, rod-shaped, polar flagellated or stalked and non-spore-forming bacterium, designated LB-2^T, was isolated from activated sludge. Growth was observed at 20-30 °C (optimum 28 °C), pH 6.0-8.0 (optimum pH 7.0) and salinity of 0-0.5% (w/v; optimum 0.5%). Phylogenetic analysis based on the 16S rRNA gene indicated that strain LB-2^T belongs to the genus Sphingomonas and showed the highest sequence similarity (96.7%) and less than 96.7% similarities to other type strains. The genome size of strain LB-2^T was 4.10 Mb, with 66.8 mol% G + C content. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strains LB-2^T and S. canadensis FWC47^T were 77.8% and 21%, respectively. The predominant cellular fatty acids were summed feature 8 (C_18:1ω7c and/or C_18 : 1ω6c) and C_16:0. The major polar lipids were aminolipid, glycolipid, sphingoglycolipid, phosphatidylcholine, phosphatidylglycerol, four unidentified lipids, glycophospholipid, phosphatidylethanolamine and diphosphatidylglycerol. The predominant respiratory quinone was Q-10 and the major polyamine was sym-homospermidine. On the basis of phenotypic, genotypic and phylogenetic evidences, strain LB-2^T represents a novel species in the genus Sphingomonas, for which the name Sphingomonas caeni sp. nov. is proposed. The type strain is LB-2^T (GDMCC 1.3630^T = NBRC 115,102^T).

Quinolinic acid catabolism is initiated by a novel four-component hydroxylase QuiA in Alcaligenes faecalis JQ191

Quinolinic acid (QA) is an essential nitrogen-containing aromatic heterocyclic compounds in organisms and it also acts as an important intermediate in chemical industry, which has strong neurotoxicity and cytotoxicity. The wide range of sources and applications caused the release and accumulation of QA in the environment which might poses a hazard to ecosystems and human health. However, few research on the degradation of QA by microorganisms and toxicity of QA and its metabolites were reported. Alcaligenes faecalis JQ191 could degrade QA but the genetic foundation of QA degradation has not been studied. In this study, the gene cluster quiA1A2A3A4 was identified from A. faecalis JQ191, which was responsible for the initial catabolism step of QA. The quiA1A2A3A4 gene cluster encodes a novel cytoplasmic four-component hydroxylase QuiA. The ¹H nuclear magnetic resonance indicated that QuiA catalyzed QA to 6-hydroxyquinolinic acid (6HQA) and the H₂¹⁸O-labeling analysis confirmed that the hydroxyl group incorporating into 6HQA was derived from water. Toxicity tests showed that the QA could approximately inhibit 20%-80% growth of Chlorella ellipsoidea, and 6HQA could relieve at least 50% QA growth inhibition of Chlorella ellipsoidea, indicating that the 6-hydroxylation of QA by QuiA is a detoxification process. This research provides new insights into the metabolism of QA by microorganism and potential application in the bioremediation of toxic pyridine derivatives-contaminated environments.

OC-052 A CHANGE IN PRESENTATION OF PARAOESOPHAGEAL HIATUS HERNIA REQUIRING SURGICAL INTERVENTION IN A DISTRICT GENERAL HOSPITAL IN THE NORTHERN REGION OF THE UNITED KINGDOM

Aim

The incidence of paraoesphageal hiatus hernia (PEH) has changed over the last several years. This study aims to ascertain the difference in the presentation of PEH requiring operative intervention at our unit because of the COVID-19 pandemic

Material & Methods

We conducted a retrospective review of procedures performed by a single surgeon for PEH in a district general hospital. We compared cases from 2016 to March 2020 and during the initial period of the COVID-19 pandemic in 2020.

Results

39 consecutive cases were identified undergoing PEH related procedures. The median age was 66 (IQR 26), with slight female predominance (M:F ratio of 5:6). 28 cases (71.8%) were performed as elective cases.

After the 2020 March lockdown, there were 10 cases of PEH repair performed with 78% performed as emergency procedures, compared to 30 cases in the preceding 5 years and 10% performed as emergency cases. Chi-square test to examine the association between COVID-19 pandemic and emergency procedure, X2(1, N=39)=14.199, p=0.000164.

Pre-COVID19 the types of procedures included 76.7% were fundoplication with suture crural closure, 10% were fundoplication with mesh repair, 3.3% biological mesh repair, 3.3% with suture closure of the crural and 6.7% had suture gastropexy. During the COVID-19 period, 44.4% were gastropexy, 33.3% were gastrostomy tube insertion and 22.2% fundoplication performed.

Conclusion

We have seen significantly more emergency PEH related procedures performed and using a variety of procedures. This leads to the consideration of whether current emergency general surgery training can equip trainees for future independent practice.

Isolated functional tricuspid regurgitation, how define patient at-risk for event?

Introduction

Functional tricuspid regurgitation (TR) is a turning point in cardiac diseases. Symptoms typically appear late, and the optimal timing for proposing a valve repair remains a challenge. We sought to analyse the characteristics of right heart remodelling in patients with significant functional TR to identify the parameters that could be used in an easily achievable and fair prognostic model predicting clinical events.

Methods

We designed a prospective observational French multicentre study including 160 patients with significant functional TR (effective regurgitant orifice area &gt;30mm2) and LVEF &gt;40%. Clinical, echocardiographic, and ECG data were collected at baseline, and at the 1- and 2-year follow-up. The primary outcome was all-cause death or hospitalization for heart failure.

Results

At 2 years, 56 patients (35%) achieved the primary outcome. The subset with events showed more advanced right heart remodelling at baseline, but similar TR severity. Right atrial volume index (RAVI) and the TAPSE/sPAP ratio, reflecting right-ventricle-pulmonary artery coupling, were 73 mL/m2 and 0.40 versus 64.7 mL/m2 and 0.50 in the event vs event-free group, respectively (both p&lt;0.05). None among all the clinical and imaging parameters tested had a significant group × time interaction. In multivariable analysis, the model including TAPSE/sPAP ratio &gt;0.4 (OR=0.41, 95%CL 0.2 to 0.82) and RAVI &gt;60 mL/m2 (OR=2.13, 95%CL 0.96 to 4.75) permitted the fairest and most parsimonious prognostic evaluation.

Conclusion

RAVI and TAPSE/sPAP are relevant for predicting the risk for event at 2-year follow-up in patient with an isolated functional TR.

Funding Acknowledgement

Type of funding sources: None.

Use of covered stents to treat complex cerebrovascular diseases: Expert consensus

The treatment of complex cerebrovascular diseases (CCVDs) at the skull base, such as complex intracranial aneurysms, carotid-cavernous sinus fistulas, and intracranial artery traumatic injuries, is a difficult clinical problem despite advances in endovascular and surgical therapies. Covered stents or stent graft insertion is a new concept for endovascular treatment that focuses on arterial wall defect reconstruction, differing from endovascular lesion embolization or flow diverter therapies. In recent years, covered stents specifically designed for cerebrovascular treatment have been applied in the clinical setting, allowing thousands of patients with CCVDs to undergo intraluminal reconstruction treatment and achieving positive results, even in the era of flow diverters. Since there is no unified reference standard for the application of covered stents for treating CCVDs, it is necessary to further standardize and guide the clinical application of this technique. Thus, we organized authoritative experts in the field of neurointervention in China to write an expert consensus, which aims to summarize the results of covered stent insertion in the treatment of CCVDs and propose suitable standards for its application in the clinical setting. Based on the contents of this consensus, clinicians can use individualized intraluminal reconstruction treatment techniques for patients with CCVDs.

Cloning of a novel tetrahydrofolate-dependent dicamba demethylase gene from dicamba-degrading consortium and characterization of the gene product

Dicamba, an important hormone-type systemic herbicide, is widely used to control more than 200 kinds of broadleaf weeds in agriculture. Due to its broad-spectrum, high efficiency and effectively killing glyphosate-resistant weeds, dicamba is considered as an excellent target herbicide for the engineering of herbicide-resistant crops. In this study, an efficient dicamba-degrading microbial consortium was enriched from soil collected from the outfall of a pesticide factory. The enriched consortium could almost completely degrade 500 mg/L of dicamba within 12 h of incubation. A novel tetrahydrofolate (THF)-dependent dicamba demethylase gene, named dmt06, was cloned from the total DNA of the enriched consortium. Dmt06 shared the highest identity (72.3%) with dicamba demethylase Dmt50 from Rhizorhabdus dicambivorans Ndbn-20. Dmt06 was expressed in Escherichia coli BL21 and purified to homogeneity using Co2+-charged nitrilotriacetic acid affinity chromatography. The purified Dmt06 catalyzed the transfer of methyl from dicamba to THF, generating the herbicidally inactive metabolite 3,6-dichlorosalicylate (3,6-DCSA) and 5-methyl-THF. The optimum pH and temperature for Dmt06 were detected to be 7.4 and 35°C, respectively. Under the optimal condition, the specific activity of Dmt06 reached 165 nmol/min/mg toward dicamba, which was much higher than that of Dmt and Dmt50. In conclusion, this study cloned a novel gene, dmt06, encoding an efficient THF-dependent dicamba demethylase, which was a good candidate for dicamba-resistant transgenic engineering.

POS1569-PARE TESTING A NEW APPROACH TO IDENTIFY AND ASSESS PATIENT-VALUED TREATMENT GOALS IN RHEUMATOID ARTHRITIS (RA): A PATIENT-ENGAGED HEALTHCARE VALUATION STRATEGY

Background

Common approaches to valuing health technologies often fail to capture outcomes that matter to patients and families. The treatment goals of people living with rheumatoid arthritis (RA) include common trial endpoints but also include other facets of disease impact. Identifying a feasible and rigorous approach to inclusion of the patient perspective is needed as trialists increasingly seek to incorporate patient-important outcomes in trial design and as varied patient-centered value assessment frameworks emerge. No standard approach is available to systemically identify and quantify patient-important outcomes, nor to include those outcomes in deliberative decision-making. We developed the Patient-Engaged Healthcare Valuation strategy, using principles of goal attainment scaling to frame survey-based goal collection directly from adults.

Objectives

To develop and test a goal-based method for collecting RA patient input for use in clinical trials and value assessment and evaluating the feasibility of this approach in people with RA.

Methods

Patient goals and domains were identified from (1) a literature review (2010-2020) of patient outcomes, goals, and preferences in RA, and (2) discussions with patients and clinicians during two meetings with a steering committee (SC) consisting of clinicians, outcomes researchers, patients/advocates, and health economists. These goals informed the development of a draft survey. Adults with RA were recruited from online patient networks to rate goal importance and suggest additional goals. SC members reviewed the survey findings and assessed feasibility of scaling up goal collection for HTA.

Results

Of 135 articles identified, 17 were retained. An inductive and iterative approach was used to identify and thematically group the final set of 36 goals into 4 domains. The draft survey was cognitively debriefed with 4 adults with RA. The first survey was administered to 20 participants; results informed item revisions and additions for the second round of data collection (n=27).

The 47 respondents were mostly White (87%), college-educated (72%) women (93%) living with RA for an average of 15 years; 75% rated their RA as moderate to severe. Free-text goals added in round 1 include: 1) finding specialists who listen to patient input on symptoms; 2) addressing loneliness or isolation; and 3) finding support from or helping others with RA. All Symptom and Life Impact goals were rated as Important or Very Important by ≥85% of participants; endorsement for Management and Treatment goals was somewhat more variable, with ≥85% endorsing these as Somewhat to Very Important. Results suggested that domains match key goals. Steering committee ratings supported the feasibility of this method.

Conclusion

Goals relevant for RA treatment evaluation can be efficiently identified and rated for importance by patients. Patient-important goals can be incorporated into deliberative healthcare valuation using this method to permit “crowd-sourced” input from people living with RA and to capture heterogeneous patient perspectives in healthcare valuation.

Table 1.

Top Goals based on rating as “Very Important” by >70% of subjects, from set of 36. “My goals for living with RA are to…”

GoalsNot ImportantSomewhat ImportantImportantVery ImportantSymptom Managementimprove the quality of my life with RA0% (0)0% (0)23% (11)77% (36)manage my RA pain0% (0)2% (1)11% (5)87% (41)reduce how my RA pain interferes with my life0% (0)9% (4)17% (8)74% (35)Life Impactreduce the ways in which RA interferes with my life0% (0)2% (1)21% (10)77% (36)be independent in my daily functioning0% (0)4% (1)15% (4)81% (22)Managing my RAfeel like I can manage my RA0% (0)2% (1)26% (12)72% (34)Treatment Featuresunderstand my RA treatment options0% (0)4% (2)21% (10)74% (35)have the information I need to make treatment decisions0% (0)0% (0)19% (9)81% (38)know what to expect with my RA treatment0% (0)2% (1)23% (11)74% (35)find treatments that are effective0% (0)0% (0)6% (3)94% (44)

Acknowledgements

I have no acknowledgements to declare.

Disclosure of Interests

None declared

Combined Multi-Atlas and Multi-Layer Perception for Alzheimer's Disease Classification

Alzheimer's disease (AD) is a progressive and irreversible neurodegenerative disease. To distinguish the stage of the disease, AD classification technology challenge has been proposed in Pattern Recognition and Computer Vision 2021 (PRCV 2021) which provides the gray volume and average cortical thickness data extracted in multiple atlases from magnetic resonance imaging (MRI). Traditional methods either train with convolutional neural network (CNN) by MRI data to adapt the spatial features of images or train with recurrent neural network (RNN) by temporal features to predict the next stage. However, the morphological features from the challenge have been extracted into discrete values. We present a multi-atlases multi-layer perceptron (MAMLP) approach to deal with the relationship between morphological features and the stage of the disease. The model consists of multiple multi-layer perceptron (MLP) modules, and morphological features extracted from different atlases will be classified by different MLP modules. The final vote of all classification results obtains the predicted disease stage. Firstly, to preserve the diversity of brain features, the most representative atlases are chosen from groups of similar atlases, and one atlas is selected in each group. Secondly, each atlas is fed into one MLP to fetch the score of the classification. Thirdly, to obtain more stable results, scores from different atlases are combined to vote the result of the classification. Based on this approach, we rank 10th among 373 teams in the challenge. The results of the experiment indicate as follows: (1) Group selection of atlas reduces the number of features required without reducing the accuracy of the model; (2) The MLP architecture achieves better performance than CNN and RNN networks in morphological features; and (3) Compared with other networks, the combination of multiple MLP networks has faster convergence of about 40% and makes the classification more stable.

Diagnosis of Amnesic Mild Cognitive Impairment Using MGS-WBC and VGBN-LM Algorithms

Computer-aided diagnosis (CAD) has undergone rapid development with the advent of advanced neuroimaging and machine learning methods. Nevertheless, how to extract discriminative features from the limited and high-dimensional data is not ideal, especially for amnesic mild cognitive impairment (aMCI) data based on resting-state functional magnetic resonance imaging (rs-fMRI). Furthermore, a robust and reliable system for aMCI detection is conducive to timely detecting and screening subjects at a high risk of Alzheimer's disease (AD). In this scenario, we first develop the mask generation strategy based on within-class and between-class criterion (MGS-WBC), which primarily aims at reducing data redundancy and excavating multiscale features of the brain. Concurrently, vector generation for brain networks based on Laplacian matrix (VGBN-LM) is presented to obtain the global features of the functional network. Finally, all multiscale features are fused to further improve the diagnostic performance of aMCI. Typical classifiers for small data learning, such as naive Bayesian (NB), linear discriminant analysis (LDA), logistic regression (LR), and support vector machines (SVMs), are adopted to evaluate the diagnostic performance of aMCI. This study helps to reveal discriminative neuroimaging features, and outperforms the state-of-the-art methods, providing new insights for the intelligent construction of CAD system of aMCI.