Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 1.599
Filter
1.
Neuropsychologia ; 199: 108883, 2024 07 04.
Article in English | MEDLINE | ID: mdl-38599567

ABSTRACT

Left smooth pursuit eye movement training in response to large-field visual motion (optokinetic stimulation) has become a promising rehabilitation method in left spatial inattention or neglect. The mechanisms underlying the therapeutic effect, however, remain unknown. During optokinetic stimulation, there is an error in visual localisation ahead of the line of sight. This could indicate a change in the brain's estimate of one's own direction of gaze. We hypothesized that optokinetic stimulation changes the brain's estimate of gaze. Because this estimate is critical for coding the locus of attention in the visual space relative to the body and across sensory modalities, its change might underlie the change in spatial attention. Here, we report that in healthy participants optokinetic stimulation causes not only a directional bias in the proprioceptive signal from the extraocular muscles, but also a corresponding shift of the locus of attention. Both changes outlasted the period of stimulation. This result forms a step in investigating a causal link between the adaptation in the sensorimotor gaze signals and the recovery in spatial neglect.


Subject(s)
Attention , Fixation, Ocular , Perceptual Disorders , Humans , Attention/physiology , Male , Perceptual Disorders/rehabilitation , Perceptual Disorders/physiopathology , Perceptual Disorders/etiology , Female , Adult , Fixation, Ocular/physiology , Photic Stimulation , Space Perception/physiology , Young Adult , Motion Perception/physiology , Proprioception/physiology , Pursuit, Smooth/physiology
2.
Hong Kong Med J ; 30(2): 110-119, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38651202

ABSTRACT

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.


Subject(s)
Elasticity Imaging Techniques , Liver Cirrhosis , Methotrexate , Psoriasis , Adult , Aged , Female , Humans , Male , Middle Aged , Biopsy , Dermatologic Agents/therapeutic use , Dermatologic Agents/adverse effects , Dermatologic Agents/administration & dosage , East Asian People , Elasticity Imaging Techniques/methods , Liver/pathology , Liver/diagnostic imaging , Liver Cirrhosis/diagnostic imaging , Liver Cirrhosis/pathology , Methotrexate/adverse effects , Methotrexate/therapeutic use , Methotrexate/administration & dosage , Psoriasis/drug therapy , Psoriasis/complications , Psoriasis/pathology , ROC Curve
3.
Med J Malaysia ; 79(2): 222-233, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38553930

ABSTRACT

INTRODUCTION: Equitable healthcare delivery is essential and requires resources to be distributed, which include assets and healthcare workers. To date, there is no gold standard for measuring the correct number of physicians to meet healthcare needs. This rapid review aims to explore measurement tools employed to optimise the distribution of hospital physicians, with a focus on ensuring fair resource allocation for equitable healthcare delivery. MATERIALS AND METHODS: A literature search was performed across PubMed, EMBASE, Emerald Insight and grey literature sources. The key terms used in the search include 'distribution', 'method', and 'physician', focusing on research articles published in English from 2002 to 2022 that described methods or tools to measure hospital-based physicians' distribution. Relevant articles were selected through a two-level screening process and critically appraised. The primary outcome is the measurement tools used to assess the distribution of hospital-based physicians. Study characteristics, tool advantages and limitations were also extracted. The extracted data were synthesised narratively. RESULTS: Out of 7,199 identified articles, 13 met the inclusion criteria. Among the selected articles, 12 were from Asia and one from Africa. The review identified eight measurement tools: Gini coefficients and Lorenz curve, Robin Hood index, Theil index, concentration index, Workload Indicator of Staffing Need method, spatial autocorrelation analysis, mixed integer linear programming model and cohortcomponent model. These tools rely on fundamental data concerning population and physician numbers to generate outputs. Additionally, five studies employed a combination of these tools to gain a comprehensive understanding of physician distribution dynamics. CONCLUSION: Measurement tools can be used to assess physician distribution according to population needs. Nevertheless, each tool has its own merits and limitations, underscoring the importance of employing a combination of tools. The choice of measuring tool should be tailored to the specific context and research objectives.


Subject(s)
Delivery of Health Care , Physicians , Humans , Hospitals , Health Personnel
4.
Bone Marrow Transplant ; 59(6): 838-848, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38443704

ABSTRACT

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.


Subject(s)
Lymphoma, T-Cell, Peripheral , Remission Induction , Transplantation, Autologous , Lymphoma, T-Cell, Peripheral/therapy , Lymphoma, T-Cell, Peripheral/mortality , Humans , Transplantation, Autologous/methods , Hematopoietic Stem Cell Transplantation/methods , Autografts
5.
RSC Chem Biol ; 5(2): 117-130, 2024 Feb 07.
Article in English | MEDLINE | ID: mdl-38333195

ABSTRACT

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.

6.
Cureus ; 16(1): e51707, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38318581

ABSTRACT

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is an uncommon and potentially fatal adverse drug reaction that can affect individuals with immunosuppression, viral reactivation, pharmacogenetic susceptibility, and recent exposures to new medications. Due to the ambiguous symptomology of DRESS syndrome along with a lack of diagnosis and treatment criteria, there can be delays in diagnosis and management. Here, we present a case of a 60-year-old female with an uncommon presentation of DRESS syndrome due to a less commonly implicated drug. We aim to bring awareness to the various presentations associated with DRESS syndrome and inform readers about current diagnostic and treatment modalities used today. In addition, this case serves to provide insights that further evidence is needed to have standardized guidelines in place to effectively diagnose and manage affected patients.

7.
Article in English | MEDLINE | ID: mdl-38083065

ABSTRACT

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.


Subject(s)
Hypertension, Pulmonary , Hypertension , Pulmonary Embolism , Humans , Hypertension, Pulmonary/diagnosis , Hypertension, Pulmonary/etiology , Hypertension, Pulmonary/surgery , Pulmonary Embolism/complications , Pulmonary Embolism/diagnosis , Pulmonary Embolism/surgery , Pulmonary Artery/surgery , Lung
8.
ACS Omega ; 8(50): 48028-48041, 2023 Dec 19.
Article in English | MEDLINE | ID: mdl-38144133

ABSTRACT

Metformin (MET), commonly marketed as a hydrochloride salt (MET-HCl) for better pharmacokinetic profile over the free base, would release a high concentration of chloride ions and cause adverse gastrointestinal effects. The preparation of chloride-free MET salts could potentially circumvent this issue. In this study, seven carboxylic acids (formic acid, acetic acid, malonic acid, succinic acid, fumaric acid, cinnamic acid, and acetylsalicylic acid) were used for preparing MET carboxylate salts. When compared with MET-HCl, all MET salts/salt hydrates show lower dissolution rates in pH 6.8 phosphate buffer. However, the cinnamic acid and acetylsalicylic acid show significantly higher dissolution rates in the forms of MET salt/salt hydrate. In the permeability test, the permeability of the MET in all of the salts was not improved. However, the permeability of cinnamic acid in the MET cinnamate is reduced, and the permeability of acetylsalicylic acid in the MET acetylsalicylate is increased. Meanwhile, at a higher crystallization temperature, the acetone solvent and a hydrolyzed product of acetylsalicylic acid react with MET respectively, leading to two unexpected 1,3,5-triazine derivatives. The results of in vitro bioactivity assays indicate that one of the triazine molecules promote glucose consumption more effectively than MET-HCl, and had relatively weak lactate production ability at low concentration. This glucose metabolism regulating compound may serve as a novel lead antihyperglycemic agent for further optimization.

10.
Front Immunol ; 14: 1252274, 2023.
Article in English | MEDLINE | ID: mdl-37965342

ABSTRACT

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.


Subject(s)
Receptors, IgG , Vaccines , Animals , Mice , CD27 Ligand/metabolism , Tumor Necrosis Factor Receptor Superfamily, Member 7/metabolism , Immunization
12.
Hong Kong Med J ; 29(5): 421-431, 2023 10.
Article in English | MEDLINE | ID: mdl-37853787

ABSTRACT

INTRODUCTION: Various cutaneous manifestations have been reported as symptoms of coronavirus disease 2019 (COVID-19), which may facilitate early clinical diagnosis and management. This study explored the incidence of cutaneous manifestations among hospitalised patients with COVID-19 and investigated its relationships with viral load, co-morbidities, and outcomes. METHODS: This retrospective study included adult patients admitted to a tertiary hospital for COVID-19 from July to September 2020. Clinical information, co-morbidities, viral load (cycle threshold [Ct] value), and outcomes were analysed. RESULTS: In total, 219 patients with confirmed COVID-19 were included. Twenty patients presented with new onset of rash. The incidence of new rash was 9.1% (95% confidence interval=6.25%-14.4%). The most common manifestations were maculopapular exanthem (n=6, 42.9%, median Ct value: 24.8), followed by livedo reticularis (n=4, 28.6%, median Ct value: 21.3), varicella-like lesions (n=2, 14.3%, median Ct value: 19.3), urticaria (n=1, 7.1%, median Ct value: 14.4), and acral chilblain and petechiae (n=1, 7.1%, median Ct value: 33.1). The median Ct values for patients with and without rash were 22.9 and 24.1, respectively (P=0.58). There were no significant differences in mortality or hospital stay between patients with and without rash. Patients with rash were more likely to display fever on admission (P<0.01). Regardless of cutaneous manifestations, patients with older age, hypertension, and chronic kidney disease stage ≥3 had significantly higher viral load and mortality (P<0.05). CONCLUSION: This study revealed no associations between cutaneous manifestation and viral load or clinical outcomes. Older patients with multiple co-morbidities have risks of high viral load and mortality; they should be closely monitored.


Subject(s)
COVID-19 , Exanthema , Adult , Humans , COVID-19/complications , SARS-CoV-2 , Cohort Studies , Viral Load , Retrospective Studies , Prognosis
13.
Bioorg Med Chem ; 95: 117498, 2023 11 15.
Article in English | MEDLINE | ID: mdl-37857256

ABSTRACT

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.


Subject(s)
COVID-19 , Lysine , Humans , Viral Proteins/metabolism , SARS-CoV-2 , Ubiquitin/metabolism , Deubiquitinating Enzymes , Oligopeptides
14.
Front Oral Health ; 4: 1266467, 2023.
Article in English | MEDLINE | ID: mdl-37808607

ABSTRACT

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.

15.
J Neurol Surg B Skull Base ; 84(5): 433-443, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37671296

ABSTRACT

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.

16.
J Neurol Surg B Skull Base ; 84(5): 423-432, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37671298

ABSTRACT

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.

18.
Clin Radiol ; 78(10): 715-723, 2023 10.
Article in English | MEDLINE | ID: mdl-37453807

ABSTRACT

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.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Humans , Carcinoma, Hepatocellular/diagnostic imaging , Carcinoma, Hepatocellular/pathology , Liver Neoplasms/pathology , Contrast Media , Sensitivity and Specificity , Gadolinium DTPA , Magnetic Resonance Imaging/methods , Retrospective Studies
19.
JACS Au ; 3(6): 1767-1774, 2023 Jun 26.
Article in English | MEDLINE | ID: mdl-37384148

ABSTRACT

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.

SELECTION OF CITATIONS
SEARCH DETAIL
...