Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 686
Filtrar
Mais filtros











Intervalo de ano de publicação
2.
Hong Kong Med J ; 30(2): 110-119, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38651202

RESUMO

INTRODUCTION: Methotrexate (MTX) is effective for treating psoriasis and psoriatic arthritis, but its potential hepatoxicity remains a concern. Liver biopsy, the gold standard for detecting MTX-induced liver injury, is invasive and carries considerable risk. Transient elastography (TE) offers a non-invasive alternative for detecting advanced liver fibrosis. This study investigated the performance of TE in detecting MTX-induced liver fibrosis among Chinese psoriasis patients, compared with liver biopsy. METHODS: This study included adult patients with clinical psoriasis. Liver stiffness measurement using TE was performed in patients receiving MTX. Exclusion criteria were known liver cirrhosis, positive viral hepatitis carrier status, or conditions influencing TE performance. Liver biopsy was performed when liver stiffness was ≥7.1 kilopascals (kPa) or when the total cumulative dose (TCD) of MTX was ≥3.5 g. RESULTS: A total of 228 patients were screened; among 34 patients who met the inclusion criteria, nine (26.5%) had significant liver fibrosis (Roenigk grade ≥3a). The area under the receiver operating characteristic curve was 0.76 (95% confidence interval=0.59-0.93; P=0.021), indicating that TE had satisfactory performance in detecting liver fibrosis. A cut-off value of 7.1 kPa of liver stiffness yielded 100% sensitivity and 68% specificity. Liver fibrosis was not correlated with the TCD of MTX or the duration of MTX use; it was significantly correlated with obesity and diabetes status (body mass index ≥30 kg/m2, waist circumference ≥138 cm, and glycated haemoglobin level ≥7.8%). CONCLUSION: Transient elastography is reliable and superior to the TCD for detecting liver fibrosis in Chinese psoriasis patients receiving MTX. Liver biopsy should be reserved for high-risk patients or patients with liver stiffness ≥11.7 kPa on TE.


Assuntos
Técnicas de Imagem por Elasticidade , Cirrose Hepática , Metotrexato , Psoríase , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Biópsia , Fármacos Dermatológicos/uso terapêutico , Fármacos Dermatológicos/efeitos adversos , Fármacos Dermatológicos/administração & dosagem , População do Leste Asiático , Técnicas de Imagem por Elasticidade/métodos , Fígado/patologia , Fígado/diagnóstico por imagem , Cirrose Hepática/diagnóstico por imagem , Cirrose Hepática/patologia , Metotrexato/efeitos adversos , Metotrexato/uso terapêutico , Metotrexato/administração & dosagem , Psoríase/tratamento farmacológico , Psoríase/complicações , Psoríase/patologia , Curva ROC
3.
Bone Marrow Transplant ; 59(6): 838-848, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38443704

RESUMO

There is currently no consensus on the role of upfront autologous transplantation (ASCT) for patients with peripheral T-cell lymphomas (PTCL), especially in patients achieving first complete remission (CR1) following chemotherapy, and data in the literature is conflicting. A systematic review and meta-analysis was performed to address this question. We searched key databases from January 2000 to February 2022. Six prospective and eleven retrospective studies were included among 2959 unique records. Median follow up in these studies ranged from 22 to 94 months. There was a trend towards benefit in PFS (HR = 0.80, 95% CI 0.62-1.05, p = 0.11) and OS (HR = 0.79, 95% CI 0.57-1.09, p = 0.15) in the ASCT compared to chemotherapy only group. Importantly, in transplant eligible patients in CR1, a significant benefit was demonstrated in both OS (HR = 0.59, 95% CI 0.36-0.95, p = 0.03) and PFS (HR = 0.61, 95% CI 0.47-0.81, p = 0.0004) in the ASCT group. Amongst the nodal PTCL subgroups, ASCT showed a significant PFS benefit for the AITL subgroup (HR = 0.43, 95% CI 0.20-0.94, p < 0.03) but not PTCL-NOS or ALK-ve ALCL subgroups. Our findings support upfront ASCT for transplant eligible PTCL patients achieving CR1 post chemotherapy. In particular, patients with AITL exhibited a significantly better PFS after upfront ASCT.


Assuntos
Linfoma de Células T Periférico , Indução de Remissão , Transplante Autólogo , Linfoma de Células T Periférico/terapia , Linfoma de Células T Periférico/mortalidade , Humanos , Transplante Autólogo/métodos , Transplante de Células-Tronco Hematopoéticas/métodos , Autoenxertos
4.
RSC Chem Biol ; 5(2): 117-130, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38333195

RESUMO

The SARS-CoV-2 papain-like protease (PLpro) is an antiviral drug target that catalyzes the hydrolysis of the viral polyproteins pp1a/1ab, so releasing the non-structural proteins (nsps) 1-3 that are essential for the coronavirus lifecycle. The LXGG↓X motif in pp1a/1ab is crucial for recognition and cleavage by PLpro. We describe molecular dynamics, docking, and quantum mechanics/molecular mechanics (QM/MM) calculations to investigate how oligopeptide substrates derived from the viral polyprotein bind to PLpro. The results reveal how the substrate sequence affects the efficiency of PLpro-catalyzed hydrolysis. In particular, a proline at the P2' position promotes catalysis, as validated by residue substitutions and mass spectrometry-based analyses. Analysis of PLpro catalyzed hydrolysis of LXGG motif-containing oligopeptides derived from human proteins suggests that factors beyond the LXGG motif and the presence of a proline residue at P2' contribute to catalytic efficiency, possibly reflecting the promiscuity of PLpro. The results will help in identifying PLpro substrates and guiding inhibitor design.

5.
Artigo em Inglês | MEDLINE | ID: mdl-38083065

RESUMO

Chronic thromboembolic pulmonary hypertension (CTEPH) involves abnormally high blood pressure in the pulmonary vessels and is associated with small vessel vasculopathy and pre-capillary proximal occlusions. Management of CTEPH disease is challenging, therefore accurate diagnosis is crucial in ensuring effective treatment and improved patient outcomes. The treatment of choice for CTEPH is pulmonary endarterectomy, which is an invasive surgical intervention to remove thrombi. Following PEA, a number of patients experience poor outcomes or worse-than-expected improvements, which may indicate that they have significant small vessel disease. A method that can predict the extent of distal remodelling may provide useful clinical information to plan appropriate CTEPH patient treatment. Here, a novel biophysical modelling approach has been developed to estimate and quantify the extent of distal remodelling. This method includes a combination of mathematical modelling and computed tomography pulmonary angiography to first model the geometry of the pulmonary arteries and to identify the under-perfused regions in CTEPH. The geometric model is then used alongside haemodynamic measurements from right heart catheterisation to predict distal remodelling. In this study, the method is tested and validated using synthetically generated remodelling data. Then, a preliminary application of this technique to patient data is shown to demonstrate the potential of the approach for use in the clinical setting.Clinical relevance- Patient-specific modelling can help provide useful information regarding the extent of distal vasculopathy on a per-patient basis, which remains challenging. Physicians can be unsure of outcomes following pulmonary endarterectomy. Therefore, the predictive aspect of the patient's response to surgery can help with clinical decision-making.


Assuntos
Hipertensão Pulmonar , Hipertensão , Embolia Pulmonar , Humanos , Hipertensão Pulmonar/diagnóstico , Hipertensão Pulmonar/etiologia , Hipertensão Pulmonar/cirurgia , Embolia Pulmonar/complicações , Embolia Pulmonar/diagnóstico , Embolia Pulmonar/cirurgia , Artéria Pulmonar/cirurgia , Pulmão
6.
Front Immunol ; 14: 1252274, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37965342

RESUMO

Introduction: T cell expressed CD27 provides costimulation upon binding to inducible membrane expressed trimeric CD70 and is required for protective CD8 T cell responses. CD27 agonists could therefore be used to bolster cellular vaccines and anti-tumour immune responses. To date, clinical development of CD27 agonists has focussed on anti-CD27 antibodies with little attention given to alternative approaches. Methods: Here, we describe the generation and activity of soluble variants of CD70 that form either trimeric (t) or dimer-of-trimer proteins and conduct side-by-side comparisons with an agonist anti-CD27 antibody. To generate a dimer-of-trimer protein (dt), we fused three extracellular domains of CD70 to the Fc domain of mouse IgG1 in a 'string of beads' configuration (dtCD70-Fc). Results: Whereas tCD70 failed to costimulate CD8 T cells, both dtCD70-Fc and an agonist anti-CD27 antibody were capable of enhancing T cell proliferation in vitro. Initial studies demonstrated that dtCD70-Fc was less efficacious than anti-CD27 in boosting a CD8 T cell vaccine response in vivo, concomitant with rapid clearance of dtCD70-Fc from the circulation. The accelerated plasma clearance of dtCD70-Fc was not due to the lack of neonatal Fc receptor binding but was dependent on the large population of oligomannose type glycosylation. Enzymatic treatment to reduce the oligomannose-type glycans in dtCD70-Fc improved its half-life and significantly enhanced its T cell stimulatory activity in vivo surpassing that of anti-CD27 antibody. We also show that whereas the ability of the anti-CD27 to boost a vaccine response was abolished in Fc gamma receptor (FcγR)-deficient mice, dtCD70-Fc remained active. By comparing the activity of dtCD70-Fc with a variant (dtCD70-Fc(D265A)) that lacks binding to FcγRs, we unexpectedly found that FcγR binding to dtCD70-Fc was required for maximal boosting of a CD8 T cell response in vivo. Interestingly, both dtCD70-Fc and dtCD70-Fc(D265A) were effective in prolonging the survival of mice harbouring BCL1 B cell lymphoma, demonstrating that a substantial part of the stimulatory activity of dtCD70-Fc in this setting is retained in the absence of FcγR interaction. Discussion: These data reveal that TNFRSF ligands can be generated with a tunable activity profile and suggest that this class of immune agonists could have broad applications in immunotherapy.


Assuntos
Receptores de IgG , Vacinas , Animais , Camundongos , Ligante CD27/metabolismo , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/metabolismo , Imunização
7.
Front Oral Health ; 4: 1266467, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37808607

RESUMO

Integration of smoking cessation program into routine oral health care has been advocated by World Health Organization since it brings extensive benefits to oral health. By tobacco cessation, patients are less prone to progression of periodontal disease, have less future tooth loss, have reduced risks of oral mucosal lesions and head and neck cancers. Evidence indicates that dentists are in a favorable position to deliver effective smoking cessation advice to improve patients' oral health. This article aims to present the current situation of smoking cessation in dental setting, including dental management of smoking patients, perceptions of dentists and dental students towards smoking cessation, challenges dental professionals face when carrying out cessation interventions. Patients' perspectives are also evaluated to provide a clearer picture of smoking cessation practice in the dental field. Review of past surveys show most patients welcome smoking cessation advice from dental practitioners. Meanwhile dentists may have wrong assumption that patients would disapprove them if they advise patient to quit smoking. On top of that, main obstacles identified are lack of training, inadequate treatment time and insufficient knowledge towards smoking cessation guidelines and referral routes. With regard to the potential barriers, evidence demonstrates that more trainings on smoking cessation strategies are needed. Future research in this aspect is also indicated to further foster the practice of smoking cessation counselling in dental setting.

8.
Bioorg Med Chem ; 95: 117498, 2023 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-37857256

RESUMO

The SARS-CoV-2 papain-like protease (PLpro) and main protease (Mpro) are nucleophilic cysteine enzymes that catalyze hydrolysis of the viral polyproteins pp1a/1ab. By contrast with Mpro, PLpro is also a deubiquitinase (DUB) that accepts post-translationally modified human proteins as substrates. Here we report studies on the DUB activity of PLpro using synthetic Nε-lysine-branched oligopeptides as substrates that mimic post-translational protein modifications by ubiquitin (Ub) or Ub-like modifiers (UBLs), such as interferon stimulated gene 15 (ISG15). Mass spectrometry (MS)-based assays confirm the DUB activity of isolated recombinant PLpro. They reveal that the sequence of both the peptide fragment derived from the post-translationally modified protein and that derived from the UBL affects PLpro catalysis; the nature of substrate binding in the S sites appears to be more important for catalytic efficiency than binding in the S' sites. Importantly, the results reflect the reported cellular substrate selectivity of PLpro, i.e. human proteins conjugated to ISG15 are better substrates than those conjugated to Ub or other UBLs. The combined experimental and modelling results imply that PLpro catalysis is affected not only by the identity of the substrate residues binding in the S and S' sites, but also by the substrate fold and the conformational dynamics of the blocking loop 2 of the PLpro:substrate complex. Nε-Lysine-branched oligopeptides thus have potential to help the identification of PLpro substrates. More generally, the results imply that MS-based assays with Nε-lysine-branched oligopeptides have potential to monitor catalysis by human DUBs and hence to inform on their substrate preferences.


Assuntos
COVID-19 , Lisina , Humanos , Proteínas Virais/metabolismo , SARS-CoV-2 , Ubiquitina/metabolismo , Enzimas Desubiquitinantes , Oligopeptídeos
9.
J Neurol Surg B Skull Base ; 84(5): 433-443, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37671296

RESUMO

Objective An operative workflow systematically compartmentalizes operations into hierarchal components of phases, steps, instrument, technique errors, and event errors. Operative workflow provides a foundation for education, training, and understanding of surgical variation. In this Part 2, we present a codified operative workflow for the translabyrinthine approach to vestibular schwannoma resection. Methods A mixed-method consensus process of literature review, small-group Delphi's consensus, followed by a national Delphi's consensus was performed in collaboration with British Skull Base Society (BSBS). Each Delphi's round was repeated until data saturation and over 90% consensus was reached. Results Seventeen consultant skull base surgeons (nine neurosurgeons and eight ENT [ear, nose, and throat]) with median of 13.9 years of experience (interquartile range: 18.1 years) of independent practice participated. There was a 100% response rate across both the Delphi rounds. The translabyrinthine approach had the following five phases and 57 unique steps: Phase 1, approach and exposure; Phase 2, mastoidectomy; Phase 3, internal auditory canal and dural opening; Phase 4, tumor debulking and excision; and Phase 5, closure. Conclusion We present Part 2 of a national, multicenter, consensus-derived, codified operative workflow for the translabyrinthine approach to vestibular schwannomas. The five phases contain the operative, steps, instruments, technique errors, and event errors. The codified translabyrinthine approach presented in this manuscript can serve as foundational research for future work, such as the application of artificial intelligence to vestibular schwannoma resection and comparative surgical research.

10.
J Neurol Surg B Skull Base ; 84(5): 423-432, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37671298

RESUMO

Objective An operative workflow systematically compartmentalizes operations into hierarchal components of phases, steps, instrument, technique errors, and event errors. Operative workflow provides a foundation for education, training, and understanding of surgical variation. In this Part 1, we present a codified operative workflow for the retrosigmoid approach to vestibular schwannoma resection. Methods A mixed-method consensus process of literature review, small-group Delphi's consensus, followed by a national Delphi's consensus, was performed in collaboration with British Skull Base Society (BSBS). Each Delphi's round was repeated until data saturation and over 90% consensus was reached. Results Eighteen consultant skull base surgeons (10 neurosurgeons and 8 ENT [ear, nose, and throat]) with median 17.9 years of experience (interquartile range: 17.5 years) of independent practice participated. There was a 100% response rate across both Delphi's rounds. The operative workflow for the retrosigmoid approach contained three phases and 40 unique steps as follows: phase 1, approach and exposure; phase 2, tumor debulking and excision; phase 3, closure. For the retrosigmoid approach, technique, and event error for each operative step was also described. Conclusion We present Part 1 of a national, multicenter, consensus-derived, codified operative workflow for the retrosigmoid approach to vestibular schwannomas that encompasses phases, steps, instruments, technique errors, and event errors. The codified retrosigmoid approach presented in this manuscript can serve as foundational research for future work, such as operative workflow analysis or neurosurgical simulation and education.

12.
Clin Radiol ; 78(10): 715-723, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37453807

RESUMO

Gadoxetic disodium (Primovist) is a hepatocyte-specific magnetic resonance imaging (MRI) contrast agent with increasing popularity with its unique dual dynamic and excretory properties in focal liver lesion detection and characterisation. In-depth knowledge of its diagnostic utility and pitfalls in hepatocellular carcinoma (HCC) and liver metastases is crucial in facilitating clinical management. The current article reviews the pearls and pitfalls in these aspects with highlights from the latest research evidence. Pearls for common usage of Primovist in HCC includes detection of precursor cancer lesions in cirrhotic patients. Hepatobiliary phase hypointensity precedes arterial phase hyperenhancement (APHE) in hepatocarcinogenesis. Hepatobiliary phase hypointense nodules without APHE can represent early or progressed hepatocellular carcinoma (HCC) and high-grade dysplastic nodules. In addition, Primovist is useful to differentiate HCC from pseudolesions. Pitfalls in diagnosing HCC include transient tachypnoea in the arterial phase, rare hepatobiliary phase hyperintense HCC, and decompensated liver cirrhosis compromising image quality. Primovist is currently the most sensitive technique in diagnosing liver metastases before curative hepatic resection. Other patterns of enhancement of liver metastases, "disappearing" liver metastases are important pitfalls. Radiologists should be aware of the diagnostic utility, limitations, and potential pitfalls for the common usage of hepatobiliary specific contrast agent in liver MRI.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Meios de Contraste , Sensibilidade e Especificidade , Gadolínio DTPA , Imageamento por Ressonância Magnética/métodos , Estudos Retrospectivos
13.
JACS Au ; 3(6): 1767-1774, 2023 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-37384148

RESUMO

The SARS-CoV-2 main protease (Mpro) plays an essential role in the coronavirus lifecycle by catalyzing hydrolysis of the viral polyproteins at specific sites. Mpro is the target of drugs, such as nirmatrelvir, though resistant mutants have emerged that threaten drug efficacy. Despite its importance, questions remain on the mechanism of how Mpro binds its substrates. Here, we apply dynamical nonequilibrium molecular dynamics (D-NEMD) simulations to evaluate structural and dynamical responses of Mpro to the presence and absence of a substrate. The results highlight communication between the Mpro dimer subunits and identify networks, including some far from the active site, that link the active site with a known allosteric inhibition site, or which are associated with nirmatrelvir resistance. They imply that some mutations enable resistance by altering the allosteric behavior of Mpro. More generally, the results show the utility of the D-NEMD technique for identifying functionally relevant allosteric sites and networks including those relevant to resistance.

15.
Lancet ; 401(10394): 2124-2137, 2023 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-37302395

RESUMO

BACKGROUND: A tumour-bed boost delivered after whole-breast radiotherapy increases local cancer-control rates but requires more patient visits and can increase breast hardness. IMPORT HIGH tested simultaneous integrated boost against sequential boost with the aim of reducing treatment duration while maintaining excellent local control and similar or reduced toxicity. METHODS: IMPORT HIGH is a phase 3, non-inferiority, open-label, randomised controlled trial that recruited women after breast-conserving surgery for pT1-3pN0-3aM0 invasive carcinoma from radiotherapy and referral centres in the UK. Patients were randomly allocated to receive one of three treatments in a 1:1:1 ratio, with computer-generated random permuted blocks used to stratify patients by centre. The control group received 40 Gy in 15 fractions to the whole breast and 16 Gy in 8 fractions sequential photon tumour-bed boost. Test group 1 received 36 Gy in 15 fractions to the whole breast, 40 Gy in 15 fractions to the partial breast, and 48 Gy in 15 fractions concomitant photon boost to the tumour-bed volume. Test group 2 received 36 Gy in 15 fractions to the whole breast, 40 Gy in 15 fractions to the partial breast, and 53 Gy in 15 fractions concomitant photon boost to the tumour-bed volume. The boost clinical target volume was the clip-defined tumour bed. Patients and clinicians were not masked to treatment allocation. The primary endpoint was ipsilateral breast tumour relapse (IBTR) analysed by intention to treat; assuming 5% 5-year incidence with the control group, non-inferiority was predefined as 3% or less absolute excess in the test groups (upper limit of two-sided 95% CI). Adverse events were assessed by clinicians, patients, and photographs. This trial is registered with the ISRCTN registry, ISRCTN47437448, and is closed to new participants. FINDINGS: Between March 4, 2009, and Sept 16, 2015, 2617 patients were recruited. 871 individuals were assigned to the control group, 874 to test group 1, and 872 to test group 2. Median boost clinical target volume was 13 cm3 (IQR 7 to 22). At a median follow-up of 74 months there were 76 IBTR events (20 for the control group, 21 for test group 1, and 35 for test group 2). 5-year IBTR incidence was 1·9% (95% CI 1·2 to 3·1) for the control group, 2·0% (1·2 to 3·2) for test group 1, and 3·2% (2·2 to 4·7) for test group 2. The estimated absolute differences versus the control group were 0·1% (-0·8 to 1·7) for test group 1 and 1·4% (0·03 to 3·8) for test group 2. The upper confidence limit for test group 1 versus the control group indicated non-inferiority for 48 Gy. Cumulative 5-year incidence of clinician-reported moderate or marked breast induration was 11·5% for the control group, 10·6% for test group 1 (p=0·40 vs control group), and 15·5% for test group 2 (p=0·015 vs control group). INTERPRETATION: In all groups 5-year IBTR incidence was lower than the 5% originally expected regardless of boost sequencing. Dose-escalation is not advantageous. 5-year moderate or marked adverse event rates were low using small boost volumes. Simultaneous integrated boost in IMPORT HIGH was safe and reduced patient visits. FUNDING: Cancer Research UK.


Assuntos
Doenças Mamárias , Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/radioterapia , Neoplasias da Mama/cirurgia , Neoplasias da Mama/patologia , Estadiamento de Neoplasias , Recidiva Local de Neoplasia/epidemiologia , Mama/patologia , Mastectomia Segmentar , Doenças Mamárias/patologia
16.
Addiction ; 118(8): 1507-1516, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36898848

RESUMO

DESIGN: This was a prospective observational study. BACKGROUND AND AIMS: The characteristics of cannabis-involved motor vehicle collisions are poorly understood. This study of injured drivers identifies demographic and collision characteristics associated with high tetrahydrocannabinol (THC) concentrations. SETTING: The study was conducted in 15 Canadian trauma centres between January 2018 and December 2021. CASES: The cases (n = 6956) comprised injured drivers who required blood testing as part of routine trauma care. MEASUREMENTS: We quantified whole blood THC and blood alcohol concentration (BAC) and recorded driver sex, age and postal code, time of crash, crash type and injury severity. We defined three driver groups: high THC (THC ≥ 5 ng/ml and BAC = 0), high alcohol (BAC ≥ 0.08% and THC = 0) and THC/BAC-negative (THC = 0 = BAC). We used logistic regression techniques to identify factors associated with group membership. FINDINGS: Most injured drivers (70.2%) were THC/BAC-negative; 1274 (18.3%) had THC > 0, including 186 (2.7%) in the high THC group; 1161 (16.7%) had BAC > 0, including 606 (8.7%) in the high BAC group. Males and drivers aged less than 45 years had higher adjusted odds of being in the high THC group (versus the THC/BAC-negative group). Importantly, 4.6% of drivers aged less than 19 years had THC ≥ 5 ng/ml, and drivers aged less than 19 years had higher unadjusted odds of being in the high THC group than drivers aged 45-54 years. Males, drivers aged 19-44 years, rural drivers, seriously injured drivers and drivers injured in single-vehicle, night-time or weekend collisions had higher adjusted odds ratios (aORs) for being in the high alcohol group (versus THC/BAC-negative). Drivers aged less than 35 or more than 65 years and drivers involved in multi-vehicle, daytime or weekday collisions had higher adjusted odds for being in the high THC group (versus the high BAC group). CONCLUSIONS: In Canada, risk factors for cannabis-related motor vehicle collisions appear to differ from those for alcohol-related motor vehicle collisions. The collision factors associated with alcohol (single-vehicle, night-time, weekend, rural, serious injury) are not associated with cannabis-related collisions. Demographic factors (young drivers, male drivers) are associated with both alcohol and cannabis-related collisions, but are more strongly associated with cannabis-related collisions.


Assuntos
Acidentes de Trânsito , Consumo de Bebidas Alcoólicas , Dronabinol , Fumar Maconha , Ferimentos e Lesões , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Acidentes de Trânsito/estatística & dados numéricos , Fatores Etários , Consumo de Bebidas Alcoólicas/sangue , Dronabinol/sangue , Fumar Maconha/sangue , Medição de Risco , Fatores de Risco , Fatores Sexuais , Ferimentos e Lesões/epidemiologia
18.
Nature ; 614(7948): 539-547, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36725933

RESUMO

Antibody responses during infection and vaccination typically undergo affinity maturation to achieve high-affinity binding for efficient neutralization of pathogens1,2. Similarly, high affinity is routinely the goal for therapeutic antibody generation. However, in contrast to naturally occurring or direct-targeting therapeutic antibodies, immunomodulatory antibodies, which are designed to modulate receptor signalling, have not been widely examined for their affinity-function relationship. Here we examine three separate immunologically important receptors spanning two receptor superfamilies: CD40, 4-1BB and PD-1. We show that low rather than high affinity delivers greater activity through increased clustering. This approach delivered higher immune cell activation, in vivo T cell expansion and antitumour activity in the case of CD40. Moreover, an inert anti-4-1BB monoclonal antibody was transformed into an agonist. Low-affinity variants of the clinically important antagonistic anti-PD-1 monoclonal antibody nivolumab also mediated more potent signalling and affected T cell activation. These findings reveal a new paradigm for augmenting agonism across diverse receptor families and shed light on the mechanism of antibody-mediated receptor signalling. Such affinity engineering offers a rational, efficient and highly tuneable solution to deliver antibody-mediated receptor activity across a range of potencies suitable for translation to the treatment of human disease.


Assuntos
Anticorpos Monoclonais , Afinidade de Anticorpos , Imunomodulação , Humanos , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacologia , Antígenos CD40/efeitos dos fármacos , Antígenos CD40/imunologia , Imunomodulação/efeitos dos fármacos , Imunomodulação/imunologia , Nivolumabe/imunologia , Nivolumabe/farmacologia
19.
Cell Rep ; 40(3): 111099, 2022 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-35858562

RESUMO

Many therapeutic antibodies deplete target cells and elicit immunotherapy by engaging activating Fc gamma receptors (FcγRs) on host effector cells. These antibodies are negatively regulated by the inhibitory FcγRIIB (CD32B). Dogma suggests inhibition is mediated through the FcγRIIB immunoreceptor tyrosine-based inhibition motif (ITIM), negatively regulating immunoreceptor tyrosine-based activation motif (ITAM)-mediated signaling from activating FcγR. To assess this, we generated experimental models expressing human (h)FcγRIIB on targets or effectors, lacking or retaining ITIM signaling capacity. We demonstrate that signaling through the hFcγRIIB ITIM is dispensable for impairing monoclonal antibody (mAb)-mediated depletion of normal and malignant murine target cells through three therapeutically relevant surface receptors (CD20, CD25, and OX40) affecting immunotherapy. We demonstrate that hFcγRIIB competition with activating FcγRs for antibody Fc, rather than ITIM signaling, is sufficient to impair activating FcγR engagement, inhibiting effector function and immunotherapy.


Assuntos
Anticorpos Monoclonais , Receptores de IgG/imunologia , Animais , Humanos , Imunoterapia , Camundongos , Receptores de IgG/metabolismo , Transdução de Sinais
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA