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1.
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
2.
Immunity ; 49(5): 958-970.e7, 2018 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-30446386

RESUMO

The costimulatory receptor 4-1BB is expressed on activated immune cells, including activated T cells. Antibodies targeting 4-1BB enhance the proliferation and survival of antigen-stimulated T cells in vitro and promote CD8 T cell-dependent anti-tumor immunity in pre-clinical cancer models. We found that T regulatory (Treg) cells infiltrating human or murine tumors expressed high amounts of 4-1BB. Intra-tumoral Treg cells were preferentially depleted by anti-4-1BB mAbs in vivo. Anti-4-1BB mAbs also promoted effector T cell agonism to promote tumor rejection. These distinct mechanisms were competitive and dependent on antibody isotype and FcγR availability. Administration of anti-4-1BB IgG2a, which preferentially depletes Treg cells, followed by either agonistic anti-4-1BB IgG1 or anti-PD-1 mAb augmented anti-tumor responses in multiple solid tumor models. An antibody engineered to optimize both FcγR-dependent Treg cell depleting capacity and FcγR-independent agonism delivered enhanced anti-tumor therapy. These insights into the effector mechanisms of anti-4-1BB mAbs lay the groundwork for translation into the clinic.


Assuntos
Anticorpos Monoclonais/farmacologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Imunomodulação/efeitos dos fármacos , Neoplasias/imunologia , Neoplasias/metabolismo , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/antagonistas & inibidores , Animais , Expressão Gênica , Humanos , Imunoglobulina G/farmacologia , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/metabolismo , Camundongos , Camundongos Knockout , Neoplasias/genética , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/genética , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/metabolismo
3.
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
4.
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
5.
Med J Malaysia ; 79(2): 222-233, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38553930

RESUMO

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.


Assuntos
Atenção à Saúde , Médicos , Humanos , Hospitais , Pessoal de Saúde
6.
Trends Biochem Sci ; 44(4): 312-330, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30612897

RESUMO

Many central biological events rely on protein-ligand interactions. The identification and characterization of protein-binding sites for ligands are crucial for the understanding of functions of both endogenous ligands and synthetic drug molecules. G protein-coupled receptors (GPCRs) typically detect extracellular signal molecules on the cell surface and transfer these chemical signals across the membrane, inducing downstream cellular responses via G proteins or ß-arrestin. GPCRs mediate many central physiological processes, making them important targets for modern drug discovery. Here, we focus on the most recent breakthroughs in finding new binding sites and binding modes of GPCRs and their potentials for the development of new medicines.


Assuntos
Descoberta de Drogas , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Sítios de Ligação/efeitos dos fármacos , Humanos , Ligantes , Preparações Farmacêuticas , Receptores Acoplados a Proteínas G/metabolismo
7.
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
8.
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
9.
Public Health ; 218: 106-113, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37011443

RESUMO

OBJECTIVES: The relationship between human mobility and nature of science (NOS) salience in the UK news media was examined. STUDY DESIGN: This is a mixed-method study. METHODS: A time series NOS salience data set was established from the content analysis of 1520 news articles related to non-pharmaceutical interventions of COVID-19. Data were taken from articles published between November 2021 and February 2022, which correlates with period of the change from pandemic to endemic status. Vector autoregressive model fitting with human mobility took place. RESULTS: The findings suggest that it was not the number of COVID-19 news articles nor the actual number of cases/deaths, but the specific NOS content that was associated with mobility change during the pandemic. Data indicate a Granger causal negative direction (P < 0.1) for the effect of the NOS salience represented in the news media on mobility in parks, as well as the effect of scientific practice, scientific knowledge and professional activities communicated in news media on recreational activities and grocery shopping. NOS salience was not associated with the mobility for transit, work or residential locations (P > 0.1). CONCLUSIONS: The findings of the study suggest that the ways in which the news media discuss epidemics can influence changes in human mobility. It is therefore essential that public health communicators emphasise the basis of scientific evidence to eliminate potential media bias in health and science communication for the promotion of public health policy. The present study approach, which combines time series and content analysis and uses an interdisciplinary lens from science communication, could also be adopted to other interdisciplinary health-related topics.


Assuntos
COVID-19 , Mídias Sociais , Humanos , COVID-19/epidemiologia , Pandemias , SARS-CoV-2 , Fatores de Tempo , Comunicação , Meios de Comunicação de Massa
10.
Hong Kong Med J ; 29(5): 421-431, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37853787

RESUMO

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.


Assuntos
COVID-19 , Exantema , Adulto , Humanos , COVID-19/complicações , SARS-CoV-2 , Estudos de Coortes , Carga Viral , Estudos Retrospectivos , Prognóstico
11.
J Chem Inf Model ; 62(12): 3090-3095, 2022 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-35695388

RESUMO

The allosteric modulation of G-protein-coupled receptors (GPCRs) by sodium ions has received significant attention as the crystal structures of several receptors show the binding of sodium ions (Na+) at the conserved D2.50. Theoretical studies have shown that extracellular Na+ would enter the allosteric D2.50 via the orthosteric site. However, it remains unclear how the bound allosteric Na+ would leave the GPCRs. In this study, we performed molecular dynamics (MD) simulations to illustrate the energy barriers of Na+ transfer through the transmembrane helix bundle of ß2AR. In contrast to the postulations from other GPCRs, the translocation of this allosteric Na+ into the intracellular side is found to be significantly difficult. Hence, the translocation direction could be receptor-specific.


Assuntos
Simulação de Dinâmica Molecular , Sódio , Regulação Alostérica , Sítio Alostérico , Íons , Receptores Acoplados a Proteínas G/química , Sódio/química
12.
Proc Natl Acad Sci U S A ; 116(18): 8709-8714, 2019 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-30975744

RESUMO

Developing highly active, multivalent ligands as therapeutic agents is challenging because of delivery issues, limited cell permeability, and toxicity. Here, we report intrinsically cell-penetrating multivalent ligands that target the trinucleotide repeat DNA and RNA in myotonic dystrophy type 1 (DM1), interrupting the disease progression in two ways. The oligomeric ligands are designed based on the repetitive structure of the target with recognition moieties alternating with bisamidinium groove binders to provide an amphiphilic and polycationic structure, mimicking cell-penetrating peptides. Multiple biological studies suggested the success of our multivalency strategy. The designed oligomers maintained cell permeability and exhibited no apparent toxicity both in cells and in mice at working concentrations. Furthermore, the oligomers showed important activities in DM1 cells and in a DM1 liver mouse model, reducing or eliminating prominent DM1 features. Phenotypic recovery of the climbing defect in adult DM1 Drosophila was also observed. This design strategy should be applicable to other repeat expansion diseases and more generally to DNA/RNA-targeted therapeutics.


Assuntos
Distrofia Miotônica/tratamento farmacológico , Proteínas de Ligação a RNA/metabolismo , Repetições de Trinucleotídeos , Animais , DNA , Proteínas de Ligação a DNA , Drosophila melanogaster , Células HeLa , Humanos , Ligantes , Fígado/metabolismo , Camundongos , Mioblastos/fisiologia , Distrofia Miotônica/genética , Proteínas com Motivo de Reconhecimento de RNA , Proteínas de Ligação a RNA/química
13.
J Card Surg ; 37(5): 1410-1412, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35148443

RESUMO

Transcatheter repair of a pseudoaneurysm of the aortic sinotubular junction with coils is quite challenging because it can cause coronary or systemic embolization of coils and aortic rupture. A 71-year-old female patient with Behcet's disease who had received repeated surgical aortic repairs presented with a complicated pseudoaneurysm. It developed not on the native aorta, but on the ascending aortic graft. It was positioned just beside the os of the attached trifurcated vascular graft trunk connecting arch vessels. To avoid reopening the sternum, which would have been fatal, coil embolization was successfully performed. This case suggests that transcatheter coil embolization might provide an alternative treatment option for such patients with a high risk of surgical mortality.


Assuntos
Falso Aneurisma , Ruptura Aórtica , Síndrome de Behçet , Embolização Terapêutica , Idoso , Falso Aneurisma/diagnóstico por imagem , Falso Aneurisma/etiologia , Falso Aneurisma/cirurgia , Ruptura Aórtica/complicações , Ruptura Aórtica/cirurgia , Síndrome de Behçet/complicações , Prótese Vascular/efeitos adversos , Embolização Terapêutica/efeitos adversos , Feminino , Humanos
14.
Br J Neurosurg ; 36(2): 284-285, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30317890

RESUMO

We report a case of isolated myxopapillary ependymoma (MPE) of the fourth ventricle. This is the thirteenth reported case of primary intracranial MPE and the fourth reported case of MPE originating from the fourth ventricle. We suggest that exhaustive clinical and radiological investigation of a spinal ependymoma must be undertaken in all cases of intracranial ependymoma.


Assuntos
Neoplasias Encefálicas , Ependimoma , Neoplasias da Medula Espinal , Ependimoma/diagnóstico por imagem , Ependimoma/cirurgia , Quarto Ventrículo/diagnóstico por imagem , Quarto Ventrículo/cirurgia , Humanos , Neoplasias da Medula Espinal/diagnóstico por imagem , Neoplasias da Medula Espinal/cirurgia
15.
Hong Kong Med J ; 28(1): 45-53, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34294603

RESUMO

INTRODUCTION: We aimed to identify gaps in knowledge, attitudes, and behaviours towards viral hepatitis among the Hong Kong public and provide insights to optimise local efforts towards achieving the World Health Organization's viral hepatitis elimination target. METHODS: A descriptive, cross-sectional, self-reported web-based questionnaire was administered to 500 individuals (aged ≥18 years) in Hong Kong. Questionnaire items explored the awareness and perceptions of viral hepatitis-related liver disease(s) and associated risk factors in English or traditional Chinese. RESULTS: The majority (>80%) were aware that chronic hepatitis B and/or C could increase the risks of developing liver cirrhosis, cancer, and/or failure. Only 55.8% had attended health screenings in the past 2 years, and 67.6% were unaware of their family's history of liver diseases. Misperceptions surrounding the knowledge and transmission risks of viral hepatitis strongly hint at the presence of social stigmatisation within the community. Many misperceived viral hepatitis as airborne or hereditary, and social behaviours (casual contact or dining with an infected person) as a transmission route. Furthermore, 62.4% were aware of hepatitis B vaccination, whereas 19.0% knew that hepatitis C cannot be prevented by vaccination. About 70% of respondents who were aware of mother-to-child transmission were willing to seek medical consultation in the event of pregnancy. Gaps in knowledge as well as the likelihood of seeking screening were observed across all age-groups and education levels. CONCLUSIONS: Comprehensive hepatitis education strategies should be developed to address gaps in knowledge among the Hong Kong public towards viral hepatitis, especially misperceptions relevant to social stigmatisation and the importance of preventive measures, including vaccination and screening, when exposed to risk factors.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Hepatite Viral Humana , Adolescente , Adulto , Estudos Transversais , Feminino , Hepatite Viral Humana/epidemiologia , Hepatite Viral Humana/prevenção & controle , Hong Kong/epidemiologia , Humanos , Transmissão Vertical de Doenças Infecciosas , Gravidez , Inquéritos e Questionários
16.
Molecules ; 27(5)2022 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-35268770

RESUMO

Neural networks and deep learning have been successfully applied to tackle problems in drug discovery with increasing accuracy over time. There are still many challenges and opportunities to improve molecular property predictions with satisfactory accuracy even further. Here, we proposed a deep-learning architecture model, namely Bidirectional long short-term memory with Channel and Spatial Attention network (BCSA), of which the training process is fully data-driven and end to end. It is based on data augmentation and SMILES tokenization technology without relying on auxiliary knowledge, such as complex spatial structure. In addition, our model takes the advantages of the long- and short-term memory network (LSTM) in sequence processing. The embedded channel and spatial attention modules in turn specifically identify the prime factors in the SMILES sequence for predicting properties. The model was further improved by Bayesian optimization. In this work, we demonstrate that the trained BSCA model is capable of predicting aqueous solubility. Furthermore, our proposed method shows noticeable superiorities and competitiveness in predicting oil-water partition coefficient, when compared with state-of-the-art graphs models, including graph convoluted network (GCN), message-passing neural network (MPNN), and AttentiveFP.


Assuntos
Aprendizado Profundo , Teorema de Bayes , Descoberta de Drogas , Redes Neurais de Computação , Solubilidade
17.
J Biol Chem ; 295(49): 16604-16613, 2020 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-32963107

RESUMO

An important mechanism of resistance to ß-lactam antibiotics is via their ß-lactamase-catalyzed hydrolysis. Recent work has shown that, in addition to the established hydrolysis products, the reaction of the class D nucleophilic serine ß-lactamases (SBLs) with carbapenems also produces ß-lactones. We report studies on the factors determining ß-lactone formation by class D SBLs. We show that variations in hydrophobic residues at the active site of class D SBLs (i.e. Trp105, Val120, and Leu158, using OXA-48 numbering) impact on the relative levels of ß-lactones and hydrolysis products formed. Some variants, i.e. the OXA-48 V120L and OXA-23 V128L variants, catalyze increased ß-lactone formation compared with the WT enzymes. The results of kinetic and product studies reveal that variations of residues other than those directly involved in catalysis, including those arising from clinically observed mutations, can alter the reaction outcome of class D SBL catalysis. NMR studies show that some class D SBL variants catalyze formation of ß-lactones from all clinically relevant carbapenems regardless of the presence or absence of a 1ß-methyl substituent. Analysis of reported crystal structures for carbapenem-derived acyl-enzyme complexes reveals preferred conformations for hydrolysis and ß-lactone formation. The observation of increased ß-lactone formation by class D SBL variants, including the clinically observed carbapenemase OXA-48 V120L, supports the proposal that class D SBL-catalyzed rearrangement of ß-lactams to ß-lactones is important as a resistance mechanism.


Assuntos
Proteínas de Bactérias/metabolismo , Lactonas/metabolismo , beta-Lactamases/metabolismo , Acinetobacter baumannii/enzimologia , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Biocatálise , Domínio Catalítico , Cristalografia por Raios X , Resistência Microbiana a Medicamentos , Hidrólise , Cinética , Lactonas/química , Espectroscopia de Ressonância Magnética , Mutagênese Sítio-Dirigida , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , beta-Lactamases/química , beta-Lactamases/genética
18.
Mov Disord ; 36(11): 2519-2529, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34390268

RESUMO

BACKGROUND: Spinocerebellar ataxia type 2 (SCA2) is a neurodegenerative disease caused by expansion of a CAG repeat in Ataxin-2 (ATXN2) gene. The mutant ATXN2 protein with a polyglutamine tract is known to be toxic and contributes to the SCA2 pathogenesis. OBJECTIVE: Here, we tested the hypothesis that the mutant ATXN2 transcript with an expanded CAG repeat (expATXN2) is also toxic and contributes to SCA2 pathogenesis. METHODS: The toxic effect of expATXN2 transcripts on SK-N-MC neuroblastoma cells and primary mouse cortical neurons was evaluated by caspase 3/7 activity and nuclear condensation assay, respectively. RNA immunoprecipitation assay was performed to identify RNA binding proteins (RBPs) that bind to expATXN2 RNA. Quantitative PCR was used to examine if ribosomal RNA (rRNA) processing is disrupted in SCA2 and Huntington's disease (HD) human brain tissue. RESULTS: expATXN2 RNA induces neuronal cell death, and aberrantly interacts with RBPs involved in RNA metabolism. One of the RBPs, transducin ß-like protein 3 (TBL3), involved in rRNA processing, binds to both expATXN2 and expanded huntingtin (expHTT) RNA in vitro. rRNA processing is disrupted in both SCA2 and HD human brain tissue. CONCLUSION: These findings provide the first evidence of a contributory role of expATXN2 transcripts in SCA2 pathogenesis, and further support the role of expHTT transcripts in HD pathogenesis. The disruption of rRNA processing, mediated by aberrant interaction of RBPs with expATXN2 and expHTT transcripts, suggest a point of convergence in the pathogeneses of repeat expansion diseases with potential therapeutic implications. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.


Assuntos
RNA , Ataxias Espinocerebelares , Animais , Ataxinas/metabolismo , Encéfalo/patologia , Camundongos , Neurônios/metabolismo , RNA/metabolismo , Proteínas de Ligação a RNA/genética , Ataxias Espinocerebelares/patologia
19.
Hong Kong Med J ; 27(4): 258-265, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33632937

RESUMO

INTRODUCTION: The objective was to investigate the changes in urology practice during coronavirus disease 2019 (COVID-19) pandemic with a perspective from our experience with severe acute respiratory syndrome (SARS) in 2003. METHODS: Institutional data from all urology centres in the Hong Kong public sector during the COVID-19 pandemic (1 Feb 2020-31 Mar 2020) and a non-COVID-19 control period (1 Feb 2019-31 Mar 2019) were acquired. An online anonymous questionnaire was used to gauge the impact of COVID-19 on resident training. The clinical output of tertiary centres was compared with data from the SARS period. RESULTS: The numbers of operating sessions, clinic attendance, cystoscopy sessions, prostate biopsy, and shockwave lithotripsy sessions were reduced by 40.5%, 28.5%, 49.6%, 44.8%, and 38.5%, respectively, across all the centres reviewed. The mean numbers of operating sessions before and during the COVID-19 pandemic were 85.1±30.3 and 50.6±25.7, respectively (P=0.005). All centres gave priority to cancer-related surgeries. Benign prostatic hyperplasia-related surgery (39.1%) and ureteric stone surgery (25.5%) were the most commonly delayed surgeries. The degree of reduction in urology services was less than that during SARS (47.2%, 55.3%, and 70.5% for operating sessions, cystoscopy, and biopsy, respectively). The mean numbers of operations performed by residents before and during the COVID-19 pandemic were 75.4±48.0 and 34.9±17.2, respectively (P=0.002). CONCLUSION: A comprehensive review of urology practice during the COVID-19 pandemic revealed changes in every aspect of practice.


Assuntos
COVID-19/epidemiologia , Controle de Doenças Transmissíveis/métodos , Internato e Residência , Padrões de Prática Médica , Síndrome Respiratória Aguda Grave/epidemiologia , Procedimentos Cirúrgicos Urológicos , Urologia , Atenção à Saúde/organização & administração , Atenção à Saúde/tendências , Surtos de Doenças/estatística & dados numéricos , Hong Kong/epidemiologia , Humanos , Internato e Residência/métodos , Internato e Residência/organização & administração , Inovação Organizacional , Padrões de Prática Médica/organização & administração , Padrões de Prática Médica/tendências , SARS-CoV-2 , Procedimentos Cirúrgicos Urológicos/métodos , Procedimentos Cirúrgicos Urológicos/estatística & dados numéricos , Urologia/educação , Urologia/estatística & dados numéricos
20.
Sensors (Basel) ; 21(2)2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-33430049

RESUMO

Combined sewer overflow structures (CSO) play an important role in sewer networks. When the local capacity of a sewer system is exceeded during intense rainfall events, they act as a "safety valve" and discharge excess rainfall run-off and wastewater directly to a natural receiving water body, thus preventing widespread urban flooding. There is a regulatory requirement that solids in CSO spills must be small and their amount strictly controlled. Therefore, a vast majority of CSOs in the UK contain screens. This paper presents the results of a feasibility study of using low-cost, low-energy acoustic sensors to remotely assess the condition of CSO screens to move to cost-effective reactive maintenance visits. In situ trials were carried out in several CSOs to evaluate the performance of the acoustic sensor under realistic screen and flow conditions. The results demonstrate that the system is robust within ±2.5% to work successfully in a live CSO environment. The observed changes in the screen condition resulted in 8-39% changes in the values of the coefficient in the proposed acoustic model. These changes are detectable and consistent with observed screen and hydraulic data. This study suggested that acoustic-based sensing can effectively monitor the CSO screen blockage conditions and hence reduce the risk of non-compliant CSO spills.

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