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1.
Eur J Med Chem Rep ; 112024 Aug.
Article in English | MEDLINE | ID: mdl-38962287

ABSTRACT

Globally, millions of infections that are resistant to antimicrobial agents are reported annually, leading to more than 700,000 fatalities. Among all, challenges arise particularly from nontuberculosis mycobacterial (NTM) and Gram-negative bacteria, as they exhibit limited treatment options in light of increasing reports of multi-drug resistant strains. Clofazimine (CFZ) is an antimycobacterial medication used to treat leprosy, and it is also known for its side effect of inducing skin pigmentation. The use of CFZ and its analogues against a broad range of Gram-negative bacteria has not been extensively investigated. In this study, we designed, synthesized and studied 11 CFZ analogues and identified examples with comparable or improved in vitro anti-bacterial activity relative to that of CFZ itself. This is the first report demonstrating in vitro activity of CFZ and its analogues against Neisseria species. The results of these studies may facilitate the development of CFZ analogues with limited side effects in humans.

2.
Clin Nutr ESPEN ; 62: 206-215, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38901943

ABSTRACT

BACKGROUND & AIMS: Chimeric Antigen Receptor (CAR) T-cell therapy has emerged as a revolutionary treatment for patients with refractory or relapsed B-cell malignancies. However, a significant proportion of patients experience negative outcomes, including severe inflammatory toxicities and relapse. Cachexia and malnutrition are known secondary syndromes in many cancer patients, attributed to the effects of active malignancy, systemic inflammation, and cumulative treatment burden; however, further research is required to accurately characterise these issues in CAR T-cell patients. The aims of this service evaluation were to explore the changes in nutritional status (malnutrition and cachexia) in CAR T-cell therapy patients and the potential impact on patient outcomes including survival. Additionally, we describe the utilisation of dietetic resources in this specific patient population in a London tertiary referral centre. METHODS: Adult haematology patients receiving licensed CD19-targeting CAR T-cell therapy at University College London Hospital between 01/04/19 and 01/09/21 were included. Data were collected from the time of treatment consent, and throughout admission to day of discharge: body weight (BW), C-reactive protein, albumin, lactate dehydrogenase, nutrition-risk screening scores (hospital-specific) and dietetic input. Clinical outcomes such as 12-month all-cause mortality, intensive care unit (ICU) admission, high-grade toxicities, and length of hospital stay (LoS) were also recorded. Cachexia and malnutrition were defined using the modified Glasgow Prognostic Score (mGPS) and Global Leadership Initiative on Malnutrition (GLIM) consensus, respectively. RESULTS: 114 patients (55.6 ± 15.1 years; 57% males) with B-cell non-Hodgkin's lymphoma (n = 109) and B-cell acute lymphoblastic leukaemia (n = 5), receiving axicabtagene ciloleucel (n = 89) and tisagenlecleucel (n = 25) were included. Median LoS for treatment was 34 (27-38) days. Prior to treatment, 31.5% of patients developed malnutrition, with pre-cachexia/refractory cachexia (mGPS) identified in 43.6% of patients. This altered nutritional status pre-treatment was significantly associated with adverse patient outcomes post-infusion; mGPS was independently associated with inferior overall survival (HR = 3.158, CI = 1.36-7.323, p = 0.007), with malnutrition and mGPS associated with increased LoS (p = 0.037), sepsis (p = 0.022) and ICU admission (p = 0.039). During admission, patients experienced significant BW loss (-5.6% (-8.8 to -2.4); p=<0.001), with 68.4% developing malnutrition. Malnutrition screening during admission identified 57% patients at-risk, with 66.6% of patients referred to dietetics; however, there was a lack of malnutrition screening and dietetic referrals prior to treatment. CONCLUSION: Pre-treatment malnutrition and cachexia was significantly associated with adverse CAR T patient outcomes, including mGPS cachexia status independently associated with inferior overall survival. Further research in this novel space is essential to confirm the extent and impact of nutritional issues, to assist with implementing dietetic pathways, and to identify potential interventions with a view to optimising outcomes.


Subject(s)
Cachexia , Immunotherapy, Adoptive , Malnutrition , Humans , Cachexia/therapy , Cachexia/mortality , Male , Female , Middle Aged , Malnutrition/therapy , Malnutrition/complications , Aged , Immunotherapy, Adoptive/adverse effects , Treatment Outcome , Adult , Nutritional Status , London
3.
Br J Haematol ; 2024 Apr 09.
Article in English | MEDLINE | ID: mdl-38594876

ABSTRACT

Radiotherapy (RT) has potential synergistic effects with chimeric antigen receptor (CAR) T but is not widely used as bridging therapy due to logistical challenges and lack of standardised protocols. We analysed RT bridging in a multicentre national cohort of large B-cell lymphoma patients approved for 3L axicabtagene ciloleucel or tisagenlecleucel across 12 UK centres. Of 763 approved patients, 722 were leukapheresed, 717 had data available on bridging therapy. 169/717 (24%) received RT bridging, 129 as single modality and 40 as combined modality treatment (CMT). Of 169 patients, 65.7% had advanced stage, 36.9% bulky disease, 86.5% elevated LDH, 41.7% international prognostic index (IPI) ≥3 and 15.2% double/triple hit at the time of approval. Use of RT bridging varied from 11% to 32% between centres and increased over time. Vein-to-vein time and infusion rate did not differ between bridging modalities. RT-bridged patients had favourable outcomes with 1-year progression-free survival (PFS) of 56% for single modality and 47% for CMT (1-year PFS 43% for systemic bridging). This is the largest cohort of LBCL patients receiving RT bridging prior to CAR T reported to date. Our results show that RT bridging can be safely and effectively used even in advanced stage and high-risk disease, with low dropout rates and excellent outcomes.

4.
Br J Haematol ; 204(2): 507-513, 2024 02.
Article in English | MEDLINE | ID: mdl-37848384

ABSTRACT

The success of CD19 Chimeric antigen receptor (CAR) T-cell therapy in large B-cell lymphoma (LBCL) has been partially offset by toxicity and logistical challenges, which off-the-shelf agents like CD20xCD3 bispecific antibodies might potentially overcome. However, when using CAR T outcomes as the 'standard-of-care comparator̕ for relapsed/refractory (r/r) LBCL, a potential learning curve with implementing a novel, complex therapy like CAR T needs to be considered. To address this, we analysed 726 UK patients intended to be treated with CD19 CAR T for r/r LBCL and compared outcomes between the first year of the national CAR T programme (Era 1; 2019) and the more recent treatment era (Era 2; 2020-2022). We identified significant improvements for Era 2 versus Era 1 in dropout rate (17% vs. 27%, p = 0.001), progression-free survival (1-year PFS 50% vs. 32%, p < 0.001) and overall survival (1-year OS 60% vs. 40%, p < 0.001). We also observed increased use of bridging therapy, improvement in bridging outcomes, more tocilizumab/corticosteroid use, reduced high-grade cytokine release syndrome (4% vs. 9%, p = 0.01) and intensive care unit admissions (20% vs. 32%, p = 0.001). Our results demonstrate significant improvement in CAR T outcomes over time, highlighting the importance of using up-to-date clinical data when comparing CAR T against new treatment options for r/r LBCL.


Subject(s)
Antibodies, Bispecific , Lymphoma, Large B-Cell, Diffuse , Receptors, Chimeric Antigen , Humans , Adaptor Proteins, Signal Transducing , Antigens, CD19 , Immunotherapy, Adoptive , United Kingdom
5.
Physiol Rep ; 11(15): e15773, 2023 08.
Article in English | MEDLINE | ID: mdl-37549967

ABSTRACT

Hypoxic ischemic encephalopathy (HIE) occurs in 2-5/1000 births, with acute kidney injury (AKI) occurring in 40%. AKI increases morbidity and mortality. Caffeine, an adenosine receptor antagonist, and photobiomodulation (PBM), working on cytochrome c oxidase, are potential treatments for AKI. To examine effects of caffeine and PBM on AKI in rats, Day 7 pups underwent a HIE intervention (Modified Rice-Vannucci model) replicating pathology observed in humans. Caffeine was administered for 3 days and/or PBM for 5 days following HIE. Weights and urine for biomarkers (NGAL, albumin, KIM-1, osteopontin) were collected prior to HIE, daily post intervention and at sacrifice. Both treatments reduced kidney injury seen on electron microscopy, but not when combined. HIE elevated urinary NGAL and albumin on Days 1-3 post-HIE, before returning to control levels. This elevation was significantly reduced by PBM or caffeine. KIM-1 was significantly elevated for 7 days post-HIE and was reduced by both treatments. Osteopontin was not altered by HIE or the treatments. Treatments, individually but not in combination, improved HIE-induced reductions in the enzymatic activity of mitochondrial complexes II-III. PBM and caffeine also improved weight gain. PBM and caffeine reduces AKI diagnosed by urinary biomarkers and confirmed by EM findings.


Subject(s)
Acute Kidney Injury , Hypoxia-Ischemia, Brain , Humans , Animals , Rats , Animals, Newborn , Lipocalin-2 , Caffeine/pharmacology , Caffeine/therapeutic use , Ischemia , Hypoxia-Ischemia, Brain/therapy , Biomarkers , Acute Kidney Injury/etiology , Acute Kidney Injury/therapy , Albumins
7.
Clin Radiol ; 78(2): 99-106, 2023 02.
Article in English | MEDLINE | ID: mdl-36639176

ABSTRACT

AIM: To identify the most influential publications relating to artificial intelligence (AI) in radiology in order to identify current trends in the literature and to highlight areas requiring further research. MATERIALS AND METHODS: A retrospective bibliometric analysis was performed of the top 100 most cited articles on this topic. Data pertaining to year of publication, publishing journal, journal impact factor, authorship, article title, institution, country, type of article, article subject, and keywords were collected. RESULTS: The number of citations per article for the top 100 list ranged from 254 to 3,576 (median 353). The number of citations per year, per article ranged from 10.4 to 894 (median 65.6). The majority of articles (n=62) were published within the last 10 years. The USA was the most common country of origin (n=44). The journal with the greatest number of articles was IEEE Transactions On Medical Imaging (n=38). University Medical Center Utrecht contributed the greatest number of articles (n=6). There were 92 original research articles, 52 of which were clinical studies. The most common clinical subjects were neuroimaging (n=25) and oncology (n=16). The most common keyword used was "deep learning" (n=34). CONCLUSION: This study provides an in-depth analysis of the top 100 most-cited papers on the use of AI in radiology. It also provides researchers with detailed insight into the current influential papers in this field, the characteristics of those studies, as well as potential future trends in this fast-developing area of radiology.


Subject(s)
Artificial Intelligence , Radiology , Humans , Retrospective Studies , Bibliometrics , Neuroimaging
8.
Osteoporos Int ; 34(1): 137-145, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36336755

ABSTRACT

Currently, there is no reproducible, widely accepted gold standard to classify osteoporotic vertebral body fractures (OVFs). The purpose of this study is to refine a method with clear rules to classify OVFs for machine learning purposes. The method was found to have moderate interobserver agreement that improved with training. INTRODUCTION: The current methods to classify osteoporotic vertebral body fractures are considered ambiguous; there is no reproducible, accepted gold standard. The purpose of this study is to refine classification methodology by introducing clear, unambiguous rules and a refined flowchart to allow consistent classification of osteoporotic vertebral body fractures. METHODS: We developed a set of rules and refinements that we called m2ABQ to classify vertebrae into five categories. A fracture-enriched database of thoracic and lumbar spine radiographs of patients 65 years of age and older was retrospectively obtained from clinical institutional radiology records using natural language processing. Five raters independently classified each vertebral body using the m2ABQ system. After each annotation round, consensus sessions that included all raters were held to discuss and finalize a consensus annotation for each vertebral body where individual raters' evaluations differed. This process led to further refinement and development of the rules. RESULTS: Each annotation round showed increase in Fleiss kappa both for presence vs absence of fracture 0.62 (0.56-0.68) to 0.70 (0.65-0.75), as well as for the whole m2ABQ scale 0.29 (0.25-0.33) to 0.54 (0.51-0.58). CONCLUSION: The m2ABQ system demonstrates moderate interobserver agreement and practical feasibility for classifying osteoporotic vertebral body fractures. Future studies to compare the method to existing studies are warranted, as well as further development of its use in machine learning purposes.


Subject(s)
Osteoporotic Fractures , Spinal Fractures , Humans , Retrospective Studies , Spinal Fractures/diagnostic imaging , Osteoporotic Fractures/diagnostic imaging , Lumbar Vertebrae/diagnostic imaging , Lumbar Vertebrae/injuries , Algorithms
9.
ESMO Open ; 7(3): 100427, 2022 06.
Article in English | MEDLINE | ID: mdl-35798468

ABSTRACT

BACKGROUND: Capecitabine- or 5-fluorouracil (5-FU)-based chemotherapy is widely used in many solid tumours, but is associated with cardiotoxicity. S-1 is a fluoropyrimidine with low rates of cardiotoxicity, but evidence regarding the safety of switching to S-1 after 5-FU- or capecitabine-associated cardiotoxicity is scarce. PATIENTS AND METHODS: This retrospective study (NCT04260269) was conducted at 13 centres in 6 countries. The primary endpoint was recurrence of cardiotoxicity after switch to S-1-based treatment due to 5-FU- or capecitabine-related cardiotoxicity: clinically meaningful if the upper boundary of the 95% confidence interval (CI; by competing risk) is not including 15%. Secondary endpoints included cardiac risk factors, diagnostic work-up, treatments, outcomes, and timelines of cardiotoxicity. RESULTS: Per protocol, 200 patients, treated between 2011 and 2020 [median age 66 years (range 19-86); 118 (59%) males], were included. Treatment intent was curative in 145 (73%). Initial cardiotoxicity was due to capecitabine (n = 170), continuous infusion 5-FU (n = 22), or bolus 5-FU (n = 8), which was administered in combination with other chemotherapy, targeted agents, or radiotherapy in 133 patients. Previous cardiovascular comorbidities were present in 99 (50%) patients. Cardiotoxic events (n = 228/200) included chest pain (n = 125), coronary syndrome/infarction (n = 69), arrhythmia (n = 22), heart failure/cardiomyopathy (n = 7), cardiac arrest (n = 4), and malignant hypertension (n = 1). Cardiotoxicity was severe or life-threatening in 112 (56%) patients and led to permanent capecitabine/5-FU discontinuation in 192 (96%). After switch to S-1, recurrent cardiotoxicity was observed in eight (4%) patients (95% CI 2.02-7.89, primary endpoint met). Events were limited to grade 1-2 and occurred at a median of 16 days (interquartile range 7-67) from therapy switch. Baseline ischemic heart disease was a risk factor for recurrent cardiotoxicity (odds ratio 6.18, 95% CI 1.36-28.11). CONCLUSION: Switching to S-1-based therapy is safe and feasible after development of cardiotoxicity on 5-FU- or capecitabine-based therapy and allows patients to continue their pivotal fluoropyrimidine-based treatment.


Subject(s)
Fluorouracil , Neoplasms , Adult , Aged , Aged, 80 and over , Capecitabine/adverse effects , Cardiotoxicity/etiology , Female , Fluorouracil/adverse effects , Humans , Male , Middle Aged , Neoplasms/drug therapy , Retrospective Studies , Young Adult
11.
Science ; 373(6559): 1156-1161, 2021 Sep 03.
Article in English | MEDLINE | ID: mdl-34516839

ABSTRACT

Dominant mutations in ubiquitously expressed transfer RNA (tRNA) synthetase genes cause axonal peripheral neuropathy, accounting for at least six forms of Charcot-Marie-Tooth (CMT) disease. Genetic evidence in mouse and Drosophila models suggests a gain-of-function mechanism. In this study, we used in vivo, cell type­specific transcriptional and translational profiling to show that mutant tRNA synthetases activate the integrated stress response (ISR) through the sensor kinase GCN2 (general control nonderepressible 2). The chronic activation of the ISR contributed to the pathophysiology, and genetic deletion or pharmacological inhibition of Gcn2 alleviated the peripheral neuropathy. The activation of GCN2 suggests that the aberrant activity of the mutant tRNA synthetases is still related to translation and that inhibiting GCN2 or the ISR may represent a therapeutic strategy in CMT.


Subject(s)
Charcot-Marie-Tooth Disease/metabolism , Glycine-tRNA Ligase/metabolism , Protein Serine-Threonine Kinases/metabolism , Stress, Physiological , Tyrosine-tRNA Ligase/metabolism , Activating Transcription Factor 4/genetics , Activating Transcription Factor 4/metabolism , Animals , Charcot-Marie-Tooth Disease/genetics , Charcot-Marie-Tooth Disease/physiopathology , Disease Models, Animal , Female , Gene Deletion , Genes, Dominant , Glycine-tRNA Ligase/genetics , Male , Mice , Mice, Mutant Strains , Motor Neurons/physiology , Protein Biosynthesis , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/therapeutic use , Protein Serine-Threonine Kinases/antagonists & inhibitors , Protein Serine-Threonine Kinases/genetics , Spinal Cord/physiopathology , Stress, Physiological/drug effects , Stress, Physiological/genetics , Stress, Physiological/physiology , Transcriptome , Tyrosine-tRNA Ligase/genetics
12.
Ecol Appl ; 31(8): e02431, 2021 12.
Article in English | MEDLINE | ID: mdl-34339067

ABSTRACT

Implementation of wildfire- and climate-adaptation strategies in seasonally dry forests of western North America is impeded by numerous constraints and uncertainties. After more than a century of resource and land use change, some question the need for proactive management, particularly given novel social, ecological, and climatic conditions. To address this question, we first provide a framework for assessing changes in landscape conditions and fire regimes. Using this framework, we then evaluate evidence of change in contemporary conditions relative to those maintained by active fire regimes, i.e., those uninterrupted by a century or more of human-induced fire exclusion. The cumulative results of more than a century of research document a persistent and substantial fire deficit and widespread alterations to ecological structures and functions. These changes are not necessarily apparent at all spatial scales or in all dimensions of fire regimes and forest and nonforest conditions. Nonetheless, loss of the once abundant influence of low- and moderate-severity fires suggests that even the least fire-prone ecosystems may be affected by alteration of the surrounding landscape and, consequently, ecosystem functions. Vegetation spatial patterns in fire-excluded forested landscapes no longer reflect the heterogeneity maintained by interacting fires of active fire regimes. Live and dead vegetation (surface and canopy fuels) is generally more abundant and continuous than before European colonization. As a result, current conditions are more vulnerable to the direct and indirect effects of seasonal and episodic increases in drought and fire, especially under a rapidly warming climate. Long-term fire exclusion and contemporaneous social-ecological influences continue to extensively modify seasonally dry forested landscapes. Management that realigns or adapts fire-excluded conditions to seasonal and episodic increases in drought and fire can moderate ecosystem transitions as forests and human communities adapt to changing climatic and disturbance regimes. As adaptation strategies are developed, evaluated, and implemented, objective scientific evaluation of ongoing research and monitoring can aid differentiation of warranted and unwarranted uncertainties.


Subject(s)
Fires , Wildfires , Ecosystem , Forests , Humans , North America
13.
14.
Steroids ; 169: 108812, 2021 05.
Article in English | MEDLINE | ID: mdl-33636208

ABSTRACT

Vitamin D status is routinely assessed by measuring circulating concentrations of 25-hydroxyvitamin D (25OHD2 or 25OHD3). However as deconjugation is not routinely incorporated into sample treatment prior to analysis, conjugated forms of 25OHD (particularly the more abundant 25OHD3) are often not considered in determining serum concentrations of total 25OHD. Two major circulating conjugated forms of 25OHD3 are 25-hydroxyvitamin D3-3-sulfate (25OHD3-S) and 25-hydroxyvitamin D3-3-glucuronide (25OHD3-G). Incorporating these two conjugated metabolites into the measurement of vitamin D status could improve our understanding of vitamin D status in health, particularly if there are changes in sulfation and glucuronidation activities. The aim of this study was to develop a liquid chromatography tandem-mass spectrometry (LC-MS/MS) targeted method for measurement of 25OHD3-S and 25OHD3-G in serum to enable comparisons with circulating levels of the free 25OHD3 form. We developed and validated a new LC-MS/MS method that measured both 25OHD3-S and 25OHD3-G following a solid phase extraction sample preparation method. Partial separation of analytes by LC, and the separation of analytes by the optimized multiple reaction monitoring transitions enabled the quantitation of both 25OHD3-S and 25OHD3-G in the single method. Serum concentrations of 25OHD3-S (24.7 ± 11.8 ng/mL) and 25OHD3-G (2.4 ± 1.2 ng/mL) were shown to be a significant proportion of circulating vitamin D metabolites in healthy donor serums. These levels of 25OHD3-S and 25OHD3-G closely associated with 25OHD3 concentrations, r = 0.728, p = 0.001 and r = 0.632, p = 0.006 respectively. However in serum from pregnant women and non-pregnant women with polycystic ovary syndrome (PCOS) significant differences in the ratios between conjugated and free 25OHD3 were observed between pregnancy groups (25OHD3/25OHD3-S and 25OHD3/25OHD3-G p < 0.001), and between healthy and PCOS subjects (25OHD3/25OHD3-G p < 0.050). Development of this novel high-throughput LC-MS/MS method indicates that 25OHD3-S and 25OHD3-G are substantial components of circulating vitamin D metabolites. The concentrations of these metabolites relative to conventional 25OHD3 may vary in different physiological and pathophysiological settings, and may therefore play an unrecognized but important role in the actions of vitamin D.


Subject(s)
Polycystic Ovary Syndrome , Calcifediol , Female , Humans , Pregnancy , Young Adult
16.
Ir J Med Sci ; 190(1): 39-40, 2021 Feb.
Article in English | MEDLINE | ID: mdl-32468414

ABSTRACT

Following the declaration by the World Health Organization (WHO) of the Covid-19 pandemic on March 11, 2020, health organisations and staff have had to adapt and restructure services in order to respond to this global health emergency. Numerous containment strategies have been, and continue to be, introduced in this rapidly evolving and fluid situation with a significant shift towards virtual or remote patient assessment. The concept of virtual patient evaluation has previously been adopted across a range of medical and surgical specialities yielding safe and efficient pathways associated with good Patient Reported Outcome Measures (PROMs) and patient satisfaction rates. Whilst the idea of virtual patient review may be perceived as counterintuitive to the basic foundations and principles of face-to-face clinical practice, the current global pandemic, now more than ever, highlights the importance, need and benefits of this care model.


Subject(s)
COVID-19/prevention & control , Patient Reported Outcome Measures , Patient Satisfaction , Telemedicine/methods , Ambulatory Care , Humans , Pandemics , SARS-CoV-2 , Telecommunications , User-Computer Interface
17.
J Asthma ; 58(8): 1032-1041, 2021 08.
Article in English | MEDLINE | ID: mdl-32308078

ABSTRACT

OBJECTIVE: Workers exposed to cobalt may develop two lung conditions, asthma or lung fibrosis. There is a relative lack of awareness of the risk of lung disease from cobalt exposure. METHODS: The state of Michigan requires physicians, and hospitals to report work-related asthma (WRA). A standardized telephone interview of each reported case was conducted. An industrial hygienist evaluated the reported cases's workplace, and a physician reviewed the results to confirm the diagnosis. This is a population-based case series of all workers in whom the exposure to cobalt was confirmed as likely responsible for WRA from 1988 to 2017. We also included an illustrative case report and data on the workplace evaluations. RESULTS: Of the 35 cases identified, 77% were males, 97.1% were white, and 62.9% had a history of smoking cigarettes. Fifteen (44%) cases were involved in manufacturing cutting tools and machine tool accessories. Symptoms improved in 28 cases (80%) when away from work. Fourteen cases (40%) had emergency department visits, while 10 (28.6%) had been hospitalized for breathing problems. Spirometry had been performed for 33 (94.3%) cases. Only 13 (37.1%) reported they were informed by a doctor that their asthma was work-related. Twenty-six inspections were conducted at 21 different workplaces, where 498 coworkers were interviewed, 55 (11%) of which had respiratory symptoms at work. Six workplaces were cited for cobalt air level higher than permissible limits. These inspections resulted in $29,380 in penalties. CONCLUSIONS: WRA secondary to cobalt is associated with significant morbidity. Most of the cases were unaware of their medical diagnosis.


Subject(s)
Asthma/chemically induced , Cobalt/adverse effects , Occupational Diseases/chemically induced , Occupational Exposure/adverse effects , Adult , Asthma/physiopathology , Female , Humans , Lung/physiopathology , Male , Middle Aged , Occupational Diseases/physiopathology , Young Adult
18.
Matrix Biol ; 95: 15-31, 2021 01.
Article in English | MEDLINE | ID: mdl-33039488

ABSTRACT

Latent-transforming growth factor beta-binding protein 2 (LTBP-2) is a major component of arterial and lung tissue and of the ciliary zonule, the system of extracellular fibers that centers and suspends the lens in the eye. LTBP-2 has been implicated previously in the development of extracellular microfibrils, although its exact role remains unclear. Here, we analyzed the three-dimensional structure of the ciliary zonule in wild type mice and used a knockout model to test the contribution of LTBP-2 to zonule structure and mechanical properties. In wild types, zonular fibers had diameters of 0.5-1.0 micrometers, with an outer layer of fibrillin-1-rich microfibrils and a core of fibrillin-2-rich microfibrils. LTBP-2 was present in both layers. The absence of LTBP-2 did not affect the number of fibers, their diameters, nor their coaxial organization. However, by two months of age, LTBP-2-depleted fibers began to rupture, and by six months, a fully penetrant ectopia lentis phenotype was present, as confirmed by in vivo imaging. To determine whether the seemingly normal fibers of young mice were compromised mechanically, we compared zonule stress/strain relationships of wild type and LTBP-2-deficient mice and developed a quasi-linear viscoelastic engineering model to analyze the resulting data. In the absence of LTBP-2, the ultimate tensile strength of the zonule was reduced by about 50%, and the viscoelastic behavior of the fibers was altered significantly. We developed a harmonic oscillator model to calculate the forces generated during saccadic eye movement. Model simulations suggested that mutant fibers are prone to failure during rapid rotation of the eyeball. Together, these data indicate that LTBP-2 is necessary for the strength and longevity of zonular fibers, but not necessarily for their formation.


Subject(s)
Cilia/genetics , Ectopia Lentis/genetics , Latent TGF-beta Binding Proteins/genetics , Longevity/genetics , Animals , Cilia/ultrastructure , Ectopia Lentis/pathology , Eye/ultrastructure , Fibroblasts/metabolism , Humans , Longevity/physiology , Mice , Mice, Knockout , Microfibrils/ultrastructure , Ocular Physiological Phenomena/genetics , Saccades/genetics , Saccades/physiology , Tensile Strength/physiology , Viscoelastic Substances/pharmacology
20.
Ir Med J ; 113(6): 95, 2020 06 11.
Article in English | MEDLINE | ID: mdl-32816430

ABSTRACT

Aim To determine baseline learning needs of Paediatricians in Ireland when caring for children with palliative care needs. Methods A questionnaire based online survey was conducted. Results One hundred and fourteen paediatricians responded to the survey, the majority were Specialist Registrars but almost half were consultant paediatricians (46% n=52). Most had never had formal education in the paediatric palliative care (57% n=48). Areas of future training that were ranked as important or highly important (percentage of respondents) included: pain management (98% n=81), management of the dying child (96% n=80), palliative care resources (95%n=79), advanced care planning (95% n=79) and communication skills (86% n=71). Those surveyed were asked to comment on the challenges of recent clinical interactions, on analysis three overarching themes emerged; best interests of the child, inadequate training and confidence and co-ordinating care. Conclusion This survey highlights the learning needs of paediatricians and will inform the development of meaningful education sessions for doctors.


Subject(s)
Education, Medical/methods , Education, Medical/trends , Learning , Palliative Care , Palliative Medicine/education , Pediatricians/education , Pediatricians/psychology , Pediatrics/education , Adult , Child , Child, Preschool , Female , Humans , Ireland , Male , Middle Aged , Surveys and Questionnaires
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