ABSTRACT
DDX3X is a ubiquitously expressed RNA helicase involved in multiple stages of RNA biogenesis. DDX3X is frequently mutated in Burkitt lymphoma, but the functional basis for this is unknown. Here, we show that loss-of-function DDX3X mutations are also enriched in MYC-translocated diffuse large B cell lymphoma and reveal functional cooperation between mutant DDX3X and MYC. DDX3X promotes the translation of mRNA encoding components of the core translational machinery, thereby driving global protein synthesis. Loss-of-function DDX3X mutations moderate MYC-driven global protein synthesis, thereby buffering MYC-induced proteotoxic stress during early lymphomagenesis. Established lymphoma cells restore full protein synthetic capacity by aberrant expression of DDX3Y, a Y chromosome homolog, the expression of which is normally restricted to the testis. These findings show that DDX3X loss of function can buffer MYC-driven proteotoxic stress and highlight the capacity of male B cell lymphomas to then compensate for this loss by ectopic DDX3Y expression.
Subject(s)
B-Lymphocytes/enzymology , DEAD-box RNA Helicases/metabolism , Lymphoma, B-Cell/enzymology , Minor Histocompatibility Antigens/metabolism , Neoplasm Proteins/biosynthesis , Proto-Oncogene Proteins c-myc/metabolism , Adolescent , Adult , Aged , Aged, 80 and over , Animals , B-Lymphocytes/pathology , Cell Line, Tumor , Child , Child, Preschool , DEAD-box RNA Helicases/genetics , Endoplasmic Reticulum Stress , Female , Gene Expression Regulation, Enzymologic , Gene Expression Regulation, Neoplastic , Humans , Loss of Function Mutation , Lymphoma, B-Cell/genetics , Lymphoma, B-Cell/pathology , Male , Mice, Transgenic , Middle Aged , Minor Histocompatibility Antigens/genetics , Neoplasm Proteins/genetics , Protein Biosynthesis , Proteome , Proteostasis , Proto-Oncogene Proteins c-myc/genetics , Young AdultABSTRACT
How a health emergency is defined and presented through the news media matters for public understanding and health outcomes. Previous studies have endeavored to identify the patterns of news sourcing in crisis coverage, specifically the interplay between political sources and health expert sources, but yielded inconclusive results. This study analyses the types and roles of actors (those entities mentioned in a story) and sources cited in news coverage of COVID-19 by surveying social media posts published by 15 UK news outlets coverage across Facebook, Twitter, and Instagram between 1 January to December 31 2020. Overall, the findings show the prominence of political sources in UK news and that the most frequently named sources were representatives of the UK government. Moreover, when stories involved political actors, they were more likely to be given a voice as a source. This demonstrates how COVID-19 was a generalized crisis for the UK, which cascaded beyond health and into other economic, social, and cultural domains. The data show some variations in sourcing patterns between the different social media platforms. The analysis suggests that this may reflect the conventions of presenting news on each platform, with some tending toward the model of consensus by prioritizing political and government sources, and others contributing to a sphere of legitimate controversy by giving voice to a wider range of sources. This is distinctive and opens up the possibility for further research on how journalists adapt stories for social media and the consequences for public health communication.
Subject(s)
COVID-19 , Health Communication , Social Media , Humans , COVID-19/epidemiology , Public Health , Health Communication/methods , United Kingdom/epidemiologyABSTRACT
Anaplastic large-cell lymphoma (ALCL) is a T-cell malignancy predominantly driven by the oncogenic anaplastic lymphoma kinase (ALK), accounting for approximately 15% of all paediatric non-Hodgkin lymphoma. Patients with central nervous system (CNS) relapse are particularly difficult to treat with a 3-year overall survival of 49% and a median survival of 23.5 months. The second-generation ALK inhibitor brigatinib shows superior penetration of the blood-brain barrier unlike the first-generation drug crizotinib and has shown promising results in ALK+ non-small-cell lung cancer. However, the benefits of brigatinib in treating aggressive paediatric ALK+ ALCL are largely unknown. We established a patient-derived xenograft (PDX) resource from ALK+ ALCL patients at or before CNS relapse serving as models to facilitate the development of future therapies. We show in vivo that brigatinib is effective in inducing the remission of PDX models of crizotinib-resistant (ALK C1156Y, TP53 loss) ALCL and furthermore that it is superior to crizotinib as a second-line approach to the treatment of a standard chemotherapy relapsed/refractory ALCL PDX pointing to brigatinib as a future therapeutic option.
Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Lymphoma, Large-Cell, Anaplastic , Child , Humans , Anaplastic Lymphoma Kinase , Crizotinib/pharmacology , Crizotinib/therapeutic use , Receptor Protein-Tyrosine Kinases/therapeutic use , Lymphoma, Large-Cell, Anaplastic/drug therapy , Lymphoma, Large-Cell, Anaplastic/pathology , Heterografts , Lung Neoplasms/drug therapy , Neoplasm Recurrence, Local/drug therapy , Organophosphorus Compounds/pharmacology , Organophosphorus Compounds/therapeutic use , Protein Kinase Inhibitors/therapeutic useABSTRACT
Anaplastic large cell lymphoma (ALCL) is a T-cell malignancy predominantly driven by a hyperactive anaplastic lymphoma kinase (ALK) fusion protein. ALK inhibitors, such as crizotinib, provide alternatives to standard chemotherapy with reduced toxicity and side effects. Children with lymphomas driven by nucleophosmin 1 (NPM1)-ALK fusion proteins achieved an objective response rate to ALK inhibition therapy of 54% to 90% in clinical trials; however, a subset of patients progressed within the first 3 months of treatment. The mechanism for the development of ALK inhibitor resistance is unknown. Through genome-wide clustered regularly interspaced short palindromic repeats (CRISPR) activation and knockout screens in ALCL cell lines, combined with RNA sequencing data derived from ALK inhibitor-relapsed patient tumors, we show that resistance to ALK inhibition by crizotinib in ALCL can be driven by aberrant upregulation of interleukin 10 receptor subunit alpha (IL10RA). Elevated IL10RA expression rewires the STAT3 signaling pathway, bypassing otherwise critical phosphorylation by NPM1-ALK. IL-10RA expression does not correlate with response to standard chemotherapy in pediatric patients, suggesting that a combination of crizotinib and chemotherapy could prevent ALK inhibitor resistance-specific relapse.
Subject(s)
Antineoplastic Agents/pharmacology , Crizotinib/pharmacology , Drug Resistance, Neoplasm/genetics , Interleukin-10 Receptor alpha Subunit/genetics , Lymphoma, Large-Cell, Anaplastic/genetics , Protein Kinase Inhibitors/pharmacology , Protein-Tyrosine Kinases/genetics , Antineoplastic Agents/therapeutic use , CRISPR-Cas Systems , Cell Line , Crizotinib/therapeutic use , Dose-Response Relationship, Drug , Gene Editing , Gene Expression , Humans , Immunohistochemistry , Interleukin-10 Receptor alpha Subunit/metabolism , Lymphoma, Large-Cell, Anaplastic/drug therapy , Lymphoma, Large-Cell, Anaplastic/metabolism , Lymphoma, Large-Cell, Anaplastic/pathology , Models, Biological , Nucleophosmin , Protein Kinase Inhibitors/therapeutic use , Protein-Tyrosine Kinases/metabolism , STAT3 Transcription Factor/metabolism , Signal Transduction/drug effectsABSTRACT
The configuration of lizard ears, where sound can reach both surfaces of the eardrums, produces a strongly directional ear, but the subsequent processing of sound direction by the auditory pathway is unknown. We report here on directional responses from the first stage, the auditory nerve. We used laser vibrometry to measure eardrum responses in Tokay geckos and in the same animals recorded 117 auditory nerve single fiber responses to free-field sound from radially distributed speakers. Responses from all fibers showed strongly lateralized activity at all frequencies, with an ovoidal directivity that resembled the eardrum directivity. Geckos are vocal and showed pronounced nerve fiber directionality to components of the call. To estimate the accuracy with which a gecko could discriminate between sound sources, we computed the Fisher information (FI) for each neuron. FI was highest just contralateral to the midline, front and back. Thus, the auditory nerve could provide a population code for sound source direction, and geckos should have a high capacity to differentiate between midline sound sources. In brain, binaural comparisons, for example, by IE (ipsilateral excitatory, contralateral inhibitory) neurons, should sharpen the lateralized responses and extend the dynamic range of directionality.NEW & NOTEWORTHY In mammals, the two ears are unconnected pressure receivers, and sound direction is computed from binaural interactions in the brain, but in lizards, the eardrums interact acoustically, producing a strongly directional response. We show strongly lateralized responses from gecko auditory nerve fibers to directional sound stimulation and high Fisher information on either side of the midline. Thus, already the auditory nerve provides a population code for sound source direction in the gecko.
Subject(s)
Acoustic Stimulation/methods , Auditory Pathways/physiology , Cochlear Nerve/physiology , Sound Localization/physiology , Vibration , Animals , Female , Lizards , MaleABSTRACT
Burkitt lymphoma (BL) accounts for almost two-thirds of all B-cell non-Hodgkin lymphoma (B-NHL) in children and adolescents and is characterised by a MYC translocation and rapid cell turnover. Intensive chemotherapeutic regimens have been developed in recent decades, including the lymphomes malins B (LMB) protocol, which have resulted in a survival rate in excess of 90%. Recent clinical trials have focused on immunochemotherapy, with the addition of rituximab to chemotherapeutic backbones, showing encouraging results. Despite these advances, relapse and refractory disease occurs in up to 10% of patients and salvage options for these carry a dismal prognosis. Efforts to better understand the molecular and functional characteristics driving relapse and refractory disease may help improve this prognosis. This study has established a paediatric BL patient-derived xenograft (PDX) resource which captures and maintains tumour heterogeneity, may be used to better characterise tumours and identify cell populations responsible for therapy resistance.
Subject(s)
Burkitt Lymphoma/pathology , Animals , Burkitt Lymphoma/genetics , Burkitt Lymphoma/therapy , Child , Disease Models, Animal , Female , Gene Expression Regulation, Neoplastic , Heterografts/pathology , Humans , Male , Mice , Neoplasm Transplantation , Tumor Cells, CulturedABSTRACT
Patients diagnosed with Anaplastic Large Cell Lymphoma (ALCL) are still treated with toxic multi-agent chemotherapy and as many as 25-50% of patients relapse. To understand disease pathology and to uncover novel targets for therapy, Whole-Exome Sequencing (WES) of Anaplastic Lymphoma Kinase (ALK)+ ALCL was performed as well as Gene-Set Enrichment Analysis. This revealed that the T-cell receptor (TCR) and Notch pathways were the most enriched in mutations. In particular, variant T349P of NOTCH1, which confers a growth advantage to cells in which it is expressed, was detected in 12% of ALK+ and ALK- ALCL patient samples. Furthermore, we demonstrate that NPM-ALK promotes NOTCH1 expression through binding of STAT3 upstream of NOTCH1. Moreover, inhibition of NOTCH1 with γ-secretase inhibitors (GSIs) or silencing by shRNA leads to apoptosis; co-treatment in vitro with the ALK inhibitor Crizotinib led to additive/synergistic anti-tumour activity suggesting this may be an appropriate combination therapy for future use in the circumvention of ALK inhibitor resistance. Indeed, Crizotinib-resistant and sensitive ALCL were equally sensitive to GSIs. In conclusion, we show a variant in the extracellular domain of NOTCH1 that provides a growth advantage to cells and confirm the suitability of the Notch pathway as a second-line druggable target in ALK+ ALCL.
Subject(s)
Lymphoma, Large-Cell, Anaplastic , Cell Line, Tumor , Humans , Lymphoma, Large-Cell, Anaplastic/drug therapy , Lymphoma, Large-Cell, Anaplastic/genetics , Mutation , Neoplasm Recurrence, Local , Protein-Tyrosine Kinases/genetics , Receptor Protein-Tyrosine Kinases/genetics , Receptor, Notch1/genetics , Exome SequencingABSTRACT
The yield of vibrationally excited OH fragments resulting from the vibrationally mediated photodissociation of methyl hydroperoxide (CH3OOH) excited in the vicinity of its 2νOH and 3νOH stretching overtones is compared with that resulting from excitation of the molecule to states with three quanta in the CH stretches and to the state with two quanta in the OH stretch and one in the OOH bend (2νOH + νOOH). We find that the OH fragment vibrational state distribution depends strongly on the vibrational state of CH3OOH prior to photodissociation. Specifically, dissociation from the CH stretch overtones and the stretch/bend combination band involving the OH stretch and OOH bend produced significantly less vibrationally excited OH fragments compared to that produced following excitation of CH3OOH to an overtone in the OH stretch. While the absence of vibrationally excited OH photoproducts following excitation of the CH overtone is not surprising, the lack of vibrationally excited OH following excitation to the 2νOH+νOOH combination band is unexpected given that photodissociation following excitation to the lower-energy 2νOH state produces OH products in v = 1 as well as in its ground state. This trend persists even when the electronic photodissociation wavelength is changed from 532 to 355 nm and thus suggests that the observed disparity arises from differences in the nature of the initially populated vibrational states. This lack of vibrationally excited OH products likely reflects the enhanced intramolecular vibrational energy redistribution associated with the stretch/bend combination level compared to the pure OH stretch overtone. Consistent with this hypothesis, photodissociation from the stretch/bend combination level of the smaller HOOH molecule produces more vibrationally excited OH fragments compared to that resulting from the corresponding state of CH3OOH. These results are investigated using second-order vibrational perturbation theory based on an internal coordinate representation of the normal modes. Consistent with the observations, the first-order correction to the wave function shows stronger coupling of the 2νOH+νOOH state to states with torsion excitation compared to the other bands considered in this study.
ABSTRACT
Anaplastic large cell lymphoma (ALCL) is an aggressive, CD30+ T cell lymphoma of children and adults. ALK fusion transcripts or mutations in the JAK-STAT pathway are observed in most ALCL tumors, but the mechanisms underlying tumorigenesis are not fully understood. Here, we show that dysregulated STAT3 in ALCL cooccupies enhancers with master transcription factors BATF3, IRF4, and IKZF1 to form a core regulatory circuit that establishes and maintains the malignant cell state in ALCL. Critical downstream targets of this network in ALCL cells include the protooncogene MYC, which requires active STAT3 to facilitate high levels of MYC transcription. The core autoregulatory transcriptional circuitry activity is reinforced by MYC binding to the enhancer regions associated with STAT3 and each of the core regulatory transcription factors. Thus, activation of STAT3 provides the crucial link between aberrant tyrosine kinase signaling and the core transcriptional machinery that drives tumorigenesis and creates therapeutic vulnerabilities in ALCL.
Subject(s)
Lymphoma, Large-Cell, Anaplastic , Signal Transduction , Adult , Child , Humans , Signal Transduction/genetics , Anaplastic Lymphoma Kinase/genetics , Anaplastic Lymphoma Kinase/metabolism , Lymphoma, Large-Cell, Anaplastic/genetics , Lymphoma, Large-Cell, Anaplastic/metabolism , Lymphoma, Large-Cell, Anaplastic/pathology , Janus Kinases/metabolism , STAT Transcription Factors/metabolism , Cell Transformation, Neoplastic , Carcinogenesis/genetics , STAT3 Transcription Factor/geneticsABSTRACT
Targeting Anaplastic lymphoma kinase (ALK) is a promising therapeutic strategy for aberrant ALK-expressing malignancies including neuroblastoma, but resistance to ALK tyrosine kinase inhibitors (ALK TKI) is a distinct possibility necessitating drug combination therapeutic approaches. Using high-throughput, genome-wide CRISPR-Cas9 knockout screens, we identify miR-1304-5p loss as a desensitizer to ALK TKIs in aberrant ALK-expressing neuroblastoma; inhibition of miR-1304-5p decreases, while mimics of this miRNA increase the sensitivity of neuroblastoma cells to ALK TKIs. We show that miR-1304-5p targets NRAS, decreasing cell viability via induction of apoptosis. It follows that the farnesyltransferase inhibitor (FTI) lonafarnib in addition to ALK TKIs act synergistically in neuroblastoma, inducing apoptosis in vitro. In particular, on combined treatment of neuroblastoma patient derived xenografts with an FTI and an ALK TKI complete regression of tumour growth is observed although tumours rapidly regrow on cessation of therapy. Overall, our data suggests that combined use of ALK TKIs and FTIs, constitutes a therapeutic approach to treat high risk neuroblastoma although prolonged therapy is likely required to prevent relapse.
Subject(s)
Anaplastic Lymphoma Kinase , Dibenzocycloheptenes , Farnesyltranstransferase , GTP Phosphohydrolases , MicroRNAs , Neuroblastoma , Piperidines , Protein Kinase Inhibitors , Pyridines , Animals , Female , Humans , Mice , Anaplastic Lymphoma Kinase/genetics , Anaplastic Lymphoma Kinase/metabolism , Anaplastic Lymphoma Kinase/antagonists & inhibitors , Apoptosis/drug effects , Apoptosis/genetics , Cell Line, Tumor , Drug Resistance, Neoplasm/genetics , Drug Resistance, Neoplasm/drug effects , Drug Synergism , Farnesyltranstransferase/antagonists & inhibitors , Farnesyltranstransferase/metabolism , Gene Expression Regulation, Neoplastic/drug effects , GTP Phosphohydrolases/genetics , GTP Phosphohydrolases/metabolism , Membrane Proteins/metabolism , Membrane Proteins/genetics , MicroRNAs/genetics , MicroRNAs/metabolism , Mutation , Neuroblastoma/drug therapy , Neuroblastoma/genetics , Neuroblastoma/pathology , Neuroblastoma/metabolism , Piperidines/pharmacology , Piperidines/therapeutic use , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/therapeutic use , Pyridines/pharmacology , Pyridines/therapeutic use , Xenograft Model Antitumor AssaysABSTRACT
Visceral organs (VO) are essential for their role in the metabolism and distribution of consumed nutrients as well as other life functions in animals. Two experiments were conducted to assess the natural longitudinal changes that the VO undergo from birth through 150 kg body weight (BW). In Experiment 1, a total of 96 crossbred pigs were euthanized at birth (pre-suckle), d 1, 2, 3, 5, 7, 14, 21 (weaning), 22, 23, 24, 26, 28, 42, 49, and 63 of age. In Experiment 2, a total of 48 crossbred pigs were euthanized at 30, 50, 75, 100, 125, and 150 kg of BW. The absolute weight of VO, and the volume and length of the gastrointestinal tract (GIT) were measured. In both experiments, the absolute weight of VO, GIT length, and their volume increased (linear, quadratic, and/or cubic, P < 0.05) as BW and age increased. In Experiment 1, the relative weight of VO (liver, kidney, heart, and lung) decreased after initially increasing within the first week of life (linear, quadratic, and/or cubic, P < 0.05), whereas the relative weight of all VO decreased as BW increased in Experiment 2 (linear and/or quadratic, P < 0.05). The relative length of small intestine decreased and that of large intestine increased as age increased in Experiment 1 (linear and quadratic, P < 0.05), whereas the relative length of the small and large intestine in Experiment 2 were relatively constant at 80% and 20% of the total length of the intestine, respectively. As age and BW increased, the relative volume of the large intestine to the total volume of the GIT increased (linear and/or quadratic, P < 0.05), while the relative volume of the small intestine decreased (linear and/or quadratic, P < 0.05). In conclusion, results showed that both absolute and relative measurements (weight, volume, and length) of VO were dependent on the BW (age) of the pig.
Subject(s)
Diet , Gastrointestinal Tract , Animal Feed/analysis , Animals , Female , Intestines , Parturition , Pregnancy , Swine , WeaningABSTRACT
State-selected photodissociation is used to record the partially rotationally resolved action spectra of CH(3)OOH in the region of its first and second OH-stretching overtones (2nu(OH) and 3nu(OH)) under free-jet expansion conditions. From an analysis of the rotational band contours for the OH-stretching states and their corresponding COOH torsion combination bands, effective rotational constants and transition dipole moment orientations are determined for the vibrational eigenstates. The level splitting between the lowest symmetric and antisymmetric pair of COOH torsion levels, 0(+) and 0(-), associated with the 2nu(OH) overtone state is found to be approximately 3.9 cm(-1). Comparison of spectra in the region of the 2nu(OH) and 2nu(OH) + nu(COOH) bands in CH(3)OOH and CD(3)OOH reveals that the spectral features in CH(3)OOH are substantially more perturbed compared to those of its deuterated counterpart, suggesting that modes involving the methyl rotor contribute significantly to promoting intramolecular vibrational energy redistribution (IVR) in CH(3)OOH. Furthermore, a comparison of the average rotational line widths in both CH(3)OOH and CD(3)OOH for the 2nu(OH) and 2nu(OH) + nu(COOH) bands appears to suggest that at these energies, adding one quanta of low-frequency COOH torsional motion does not enhance the IVR rate relative to that of the pure OH-stretching overtone.
Subject(s)
Hydroxyl Radical/chemistry , Peroxides/chemistry , Quantum Theory , RotationABSTRACT
This article was originally published under standard licence, but has now been made available under a [CC BY 4.0] license. The PDF and HTML versions of the paper have been modified accordingly.
ABSTRACT
Resistance to anaplastic lymphoma kinase (ALK)-targeted therapy in ALK-positive non-small cell lung cancer has been reported, with the majority of acquired resistance mechanisms relying on bypass signaling. To proactively identify resistance mechanisms in ALK-positive neuroblastoma (NB), we herein employ genome-wide CRISPR activation screens of NB cell lines treated with brigatinib or ceritinib, identifying PIM1 as a putative resistance gene, whose high expression is associated with high-risk disease and poor survival. Knockdown of PIM1 sensitizes cells of differing MYCN status to ALK inhibitors, and in patient-derived xenografts of high-risk NB harboring ALK mutations, the combination of the ALK inhibitor ceritinib and PIM1 inhibitor AZD1208 shows significantly enhanced anti-tumor efficacy relative to single agents. These data confirm that PIM1 overexpression decreases sensitivity to ALK inhibitors in NB, and suggests that combined front-line inhibition of ALK and PIM1 is a viable strategy for the treatment of ALK-positive NB independent of MYCN status.
Subject(s)
Anaplastic Lymphoma Kinase/antagonists & inhibitors , Drug Resistance, Neoplasm/genetics , Neuroblastoma/genetics , Proto-Oncogene Proteins c-pim-1/genetics , Anaplastic Lymphoma Kinase/genetics , Animals , Apoptosis/drug effects , Biphenyl Compounds/pharmacology , Cell Line, Tumor , Gene Knockdown Techniques , Humans , Mice , N-Myc Proto-Oncogene Protein/genetics , Neuroblastoma/drug therapy , Organophosphorus Compounds/therapeutic use , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/therapeutic use , Proto-Oncogene Proteins c-pim-1/antagonists & inhibitors , Pyrimidines/pharmacology , Pyrimidines/therapeutic use , Sulfones/pharmacology , Sulfones/therapeutic use , Thiazolidines/pharmacology , Xenograft Model Antitumor AssaysABSTRACT
The OH stretching overtones and OH stretch-HOOC torsion combination bands of methyl hydroperoxide are investigated using action spectroscopy initiated through vibrational state selected photodissociation. Our results for the room temperature spectra covering the 2nu(OH)-5nu(OH) regions suggest that the coarse vibrational structures appearing in the spectra can be understood using a simple two-dimensional vibration-torsion model involving the OH stretch and COOH torsion consistent with what has been previously reported. However, investigation of the jet-cooled spectrum for the 2nu(OH) band along with the results of ab initio calculations using coupled cluster methods reveals that the dependence of the transition dipole moment on the HOOC torsion angle cannot be neglected when simulating intensities of OH stretching overtone bands, as has been suggested by earlier room temperature studies. The present results demonstrate that transitions between torsional levels of different symmetries, which arise from the dependence of the dipole moment mu(r,tau) on the torsional angle, contribute significantly to the intensities of the vibrational overtone bands and are important in interpreting the temperature dependence of the spectral band profiles. Contributions from these transitions are largest for the 2nu(OH) and 3nu(OH) levels and fall off gradually for the higher overtones. In addition, results are presented investigating the orbital interactions in CH(3)OOH that influence changes in the HOOC adiabatic torsion potential with increased OH stretching excitation.
Subject(s)
Acetic Acid/chemistry , Hydroxyl Radical/chemistry , Quantum Theory , Acetic Acid/chemical synthesis , Computer Simulation , Models, Chemical , Photochemistry , Spectrometry, Fluorescence , Temperature , VibrationABSTRACT
BACKGROUND: The volar approach is commonly used for plating intra-articular fractures of the distal radius. Despite this, certain fracture configurations are more suitable for dorsal plate fixation. This technique has not gained favour due to the reported high incidence of extensor tendon irritation and attrition ruptures. With the advent of lower profile plates this risk has decreased. METHODS: We report on forty-six cases performed in a tertiary hand centre between January 2011 and May 2014. Patients were identified from a database of distal radius fractures treated with open reduction and internal fixation. Pre-operative radiographs and computed tomogram (CT) scans were reviewed to classify fractures and evaluate fracture configurations. Dorsal displacement of fracture fragments was present in all cases. Records and imaging were reviewed to assess bony union and complications including tendon irritation, rupture and need for further surgery. RESULTS: Plate placement was dependent on the degree of comminution in each fracture component. The combination of a dorsal and radial styloid plate was used in 52% of cases. There were no cases of tendon rupture and one case of post-operative loss of reduction. Removal of metal was performed in ten patients, mainly to improve motion and for tendon irritation (four cases each). CONCLUSIONS: Even though technically challenging, dorsal plating is useful in cases of dorsal fragment displacement and comminution, as well as complex AO-23C3 fractures with involvement of the lunate fossa. It allows stable reduction of the dorso-ulnar fragment which is important to restore DRUJ anatomy. The rate of tendon irritation and rupture is lower when compared to earlier plate designs, and removal of metal is only necessary in a few cases.
Subject(s)
Bone Plates , Fracture Fixation, Internal/instrumentation , Fractures, Comminuted/surgery , Intra-Articular Fractures/surgery , Radius Fractures/surgery , Wrist Joint , Humans , Retrospective Studies , Treatment OutcomeABSTRACT
Human type-2 CD8+ T cells are a cell population with potentially important roles in allergic disease. We investigated this in the context of severe asthma with persistent airway eosinophilia-a phenotype associated with high exacerbation risk and responsiveness to type-2 cytokine-targeted therapies. In two independent cohorts we show that, in contrast to Th2 cells, type-2 cytokine-secreting CD8+CRTH2+ (Tc2) cells are enriched in blood and airways in severe eosinophilic asthma. Concentrations of prostaglandin D2 (PGD2) and cysteinyl leukotriene E4 (LTE4) are also increased in the airways of the same group of patients. In vitro PGD2 and LTE4 function synergistically to trigger Tc2 cell recruitment and activation in a TCR-independent manner. These lipids regulate diverse genes in Tc2 cells inducing type-2 cytokines and many other pro-inflammatory cytokines and chemokines, which could contribute to eosinophilia. These findings are consistent with an important innate-like role for human Tc2 cells in severe eosinophilic asthma and suggest a potential target for therapeutic intervention in this and other diseases.
Subject(s)
Asthma/drug therapy , CD8-Positive T-Lymphocytes/drug effects , Lipids/pharmacology , Pulmonary Eosinophilia/drug therapy , A549 Cells , Asthma/immunology , CD8-Positive T-Lymphocytes/immunology , Cell Line, Tumor , Chemokines/immunology , Cytokines/immunology , Humans , Hypersensitivity/drug therapy , Inflammation/drug therapy , Leukotriene E4/immunology , Lymphocyte Count/methods , Mast Cells/drug effects , Mast Cells/immunology , Prostaglandin D2/immunology , Pulmonary Eosinophilia/immunology , Th2 Cells/drug effects , Th2 Cells/immunologyABSTRACT
AIM: To determine technical considerations and radiographic outcomes of the Synthes volar rim distal radius plate to treat complex intra-articular fractures. METHODS: This review highlights technical considerations learnt using this implant since it was introduced in a major trauma unit in November 2011, including anatomical reduction and whether this was maintained radiographically. RESULTS: Twenty-six of the 382 internally fixed distal radial fractures at our unit (6.8%) were deemed to require this plate in order to achieve optimal fracture fixation between November 2011 and May 2014. A further dorsal and/or radial plate was necessary in 35% and variable angle screws were used in 54% of cases. Post-operatively, mean radial height, inclination, volar tilt and ulnar variance restored were 11.7 mm, 21º, 4.3º and -1.2 mm respectively. There were no cases of non-union or flexor/extensor tendon rupture; one case of loss of fracture reduction. Overall incidence of plate removal was 15% with one plate removed for flexor and one for extensor tendon irritation. CONCLUSION: The use of a rim plate enables control of challenging far distal fracture patterns. However, additional plates were required to improve and maintain reduction. Variable angle screws were necessary in half the cases to avoid intra-articular screw penetration. If used judiciously, this implant can achieve stable fixation despite the complexity of the fracture pattern.