Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 76
Filtrar
1.
Tumour Biol ; 45(1): 73-80, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37694331

RESUMO

Proprotein convertase subtilisin/kexin type 9 (PCSK9) binds to low-density lipoprotein (LDL) receptor and fatty acid translocase CD36, inducing lysosomal degradation of these two receptors in the liver cells. Both monoclonal antibody (mAb) and small-interfering RNA (siRNA) targeting PCSK9 have been designed for treatment of familial hypercholesterolemia recently, with elevating LDL receptors on the liver cell surface and increasing LDL uptake as the main beneficial mechanism. However, given that the binding domains of PCSK9 for LDL receptor and CD36 are different, and PCSK9 mAb only attacks the domain for LDL receptor, CD36 expression remains partially controlled under PCSK9 mAb treatment. In contrast, PCSK9 siRNA brings on complete loss of PCSK9, resulting in overexpression of CD36. Based on the fact that CD36 is a key factor in the pathogenesis of non-alcoholic fatty liver disease (NAFLD) and subsequent hepatocellular carcinoma (HCC), the risk of developing NAFLD and HCC on long-term use of PCSK9 siRNA is thus raised as a hypothesis. Additionally, because CD36 is also involved in the promotion of malignant diseases other than HCC, such as acute myeloid leukemia, gastric cancer, breast cancer, and colorectal cancer, the speculative danger of flourishing these malignancies by PCSK9 siRNA is discussed as well.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Hepatopatia Gordurosa não Alcoólica , Humanos , Regulação para Cima , RNA Interferente Pequeno/genética , Carcinoma Hepatocelular/genética , Pró-Proteína Convertase 9/genética , Neoplasias Hepáticas/genética , Receptores de LDL , Anticorpos Monoclonais , Subtilisinas
2.
Nutr Health ; 29(1): 5-7, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35702043

RESUMO

Background: The overall prevalence of diabetes in the world has risen substantially in the past several decades, so have complications and mortalities associated with it. Aim: Prevention strategies for diabetes thus become an urgent public health need for reducing the burden of diabetes. Methods: Ractopamine, a ß1/2-adrenergic receptor agonist, has been approved for use in finishing swine, cattle, and turkey in countries where meat exporting brings tremendous economic benefits. This leanness enhancer is recently found to be a full agonist at trace amine-associated receptor 1 also. A thorough literature review was performed to assess possible effects of ractopamine on glucose metabolism. Results: Activating ß-adrenoceptor could lead to glucose-lowering effects independent of insulin while activation on trace amine-associated receptor 1 induces an incretin-like signaling on insulin-secreting pancreatic ß-cells. Conclusion: Accordingly, it is hypothesized that long-term consuming meat containing ractopamine might lower the risk of type 2 diabetes.


Assuntos
Diabetes Mellitus Tipo 2 , Insulinas , Humanos , Animais , Suínos , Bovinos , Agonistas Adrenérgicos beta/uso terapêutico , Agonistas Adrenérgicos beta/farmacologia , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/prevenção & controle , Fenetilaminas/uso terapêutico , Fenetilaminas/farmacologia , Carne
3.
Nutr Health ; 29(2): 171-174, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36266952

RESUMO

Background: Substance misuse brings tremendous harm to global health. Strategies for the treatment and prevention of drug addiction are in urgent need. Aim: Trace amine-associated receptor 1 (TAAR1) widely distributed in the central nervous system has been identified as a hopeful target in the management of certain substance abuse. Discovery of food ingredients that act on TAAR1 might help health care providers develop chemoprevention for substance misuse disorders. Methods: Animal experiments clearly demonstrated the capability of TAAR1 agonists in attenuating addictive behavior regarding cocaine, nicotine, methamphetamine, and morphine. Ractopamine, a livestock feed additive used in the United States for over 20 years, has proven to be a full TAAR1 agonist. Literature review and internet web database survey were performed to see if ractopamine residues in meat could affect substance addiction behavior. Results: Integrating all available epidemiologic studies revealed that the prevalence of cocaine, nicotine, methamphetamine, and opioid misuse showed steadily downward or stable trends coincidently during the same time period of ractopamine use in the United States. Conclusion: A hypothesis is thus raised here that ractopamine residues in meat might have contributed secretly to the smoothened prevalence curves of cocaine, nicotine, methamphetamine, and opioids addiction.


Assuntos
Cocaína , Metanfetamina , Transtornos Relacionados ao Uso de Substâncias , Animais , Humanos , Estados Unidos , Metanfetamina/efeitos adversos , Nicotina/efeitos adversos , Morfina , Carne , Ração Animal
4.
Am J Epidemiol ; 191(6): 1140-1151, 2022 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-35238335

RESUMO

The inverse probability of treatment weighting (IPTW) approach is popular for evaluating causal effects in observational studies, but extreme propensity scores could bias the estimator and induce excessive variance. Recently, the overlap weighting approach has been proposed to alleviate this problem, which smoothly down-weights the subjects with extreme propensity scores. Although advantages of overlap weighting have been extensively demonstrated in literature with continuous and binary outcomes, research on its performance with time-to-event or survival outcomes is limited. In this article, we propose estimators that combine propensity score weighting and inverse probability of censoring weighting to estimate the counterfactual survival functions. These estimators are applicable to the general class of balancing weights, which includes IPTW, trimming, and overlap weighting as special cases. We conduct simulations to examine the empirical performance of these estimators with different propensity score weighting schemes in terms of bias, variance, and 95% confidence interval coverage, under various degrees of covariate overlap between treatment groups and censoring rates. We demonstrate that overlap weighting consistently outperforms IPTW and associated trimming methods in bias, variance, and coverage for time-to-event outcomes, and the advantages increase as the degree of covariate overlap between the treatment groups decreases.


Assuntos
Pontuação de Propensão , Viés , Causalidade , Simulação por Computador , Humanos
5.
Lancet ; 398(10297): 314-324, 2021 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-34175021

RESUMO

BACKGROUND: CARTITUDE-1 aimed to assess the safety and clinical activity of ciltacabtagene autoleucel (cilta-cel), a chimeric antigen receptor T-cell therapy with two B-cell maturation antigen-targeting single-domain antibodies, in patients with relapsed or refractory multiple myeloma with poor prognosis. METHODS: This single-arm, open-label, phase 1b/2 study done at 16 centres in the USA enrolled patients aged 18 years or older with a diagnosis of multiple myeloma and an Eastern Cooperative Oncology Group performance status score of 0 or 1, who received 3 or more previous lines of therapy or were double-refractory to a proteasome inhibitor and an immunomodulatory drug, and had received a proteasome inhibitor, immunomodulatory drug, and anti-CD38 antibody. A single cilta-cel infusion (target dose 0·75 × 106 CAR-positive viable T cells per kg) was administered 5-7 days after start of lymphodepletion. The primary endpoints were safety and confirmation of the recommended phase 2 dose (phase 1b), and overall response rate (phase 2) in all patients who received treatment. Key secondary endpoints were duration of response and progression-free survival. This trial is registered with ClinicalTrials.gov, NCT03548207. FINDINGS: Between July 16, 2018, and Oct 7, 2019, 113 patients were enrolled. 97 patients (29 in phase 1b and 68 in phase 2) received a cilta-cel infusion at the recommended phase 2 dose of 0·75 × 106 CAR-positive viable T cells per kg. As of the Sept 1, 2020 clinical cutoff, median follow-up was 12·4 months (IQR 10·6-15·2). 97 patients with a median of six previous therapies received cilta-cel. Overall response rate was 97% (95% CI 91·2-99·4; 94 of 97 patients); 65 (67%) achieved stringent complete response; time to first response was 1 month (IQR 0·9-1·0). Responses deepened over time. Median duration of response was not reached (95% CI 15·9-not estimable), neither was progression-free survival (16·8-not estimable). The 12-month progression-free rate was 77% (95% CI 66·0-84·3) and overall survival rate was 89% (80·2-93·5). Haematological adverse events were common; grade 3-4 haematological adverse events were neutropenia (92 [95%] of 97 patients), anaemia (66 [68%]), leukopenia (59 [61%]), thrombocytopenia (58 [60%]), and lymphopenia (48 [50%]). Cytokine release syndrome occurred in 92 (95%) of 97 patients (4% were grade 3 or 4); with median time to onset of 7·0 days (IQR 5-8) and median duration of 4·0 days (IQR 3-6). Cytokine release syndrome resolved in all except one with grade 5 cytokine release syndrome and haemophagocytic lymphohistiocytosis. CAR T-cell neurotoxicity occurred in 20 (21%) patients (9% were grade 3 or 4). 14 deaths occurred in the study; six due to treatment-related adverse events, five due to progressive disease, and three due to treatment-unrelated adverse events. INTERPRETATION: A single cilta-cel infusion at the target dose of 0·75 × 106 CAR-positive viable T cells per kg led to early, deep, and durable responses in heavily pretreated patients with multiple myeloma with a manageable safety profile. The data from this study formed the basis for recent regulatory submissions. FUNDING: Janssen Research & Development and Legend Biotech.


Assuntos
Antígeno de Maturação de Linfócitos B/administração & dosagem , Imunoterapia Adotiva/métodos , Mieloma Múltiplo/tratamento farmacológico , Receptores de Antígenos Quiméricos/administração & dosagem , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Intervalo Livre de Progressão , Estados Unidos
6.
Int J Mol Sci ; 23(16)2022 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-36012532

RESUMO

Anthracycline-induced cardiomyopathy has been noted as a non-neglectable issue in the field of clinical oncology. Remarkable progress has been achieved in searching for inherited susceptible genetic deficits underlying anthracycline cardiotoxicity in the past several years. In this case report, we present the preliminary results of a genetic study in a young male patient who was treated with standard dose anthracycline-based chemotherapy for his acute myeloid leukemia and attacked by acute congestive heart failure after just two courses of therapy. After a survey of 76 target genes, an in-frame deletion of the titin gene was recognized as the most possible genetic defect responsible for his cardiomyopathy caused by anthracycline. This defect proved to pass down from the patient's mother and did not exist in seven unrelated chemotherapy-treated cancer patients without chemotherapy-induced cardiomyopathy and four other healthy volunteer DNA donors.


Assuntos
Antraciclinas , Cardiomiopatias , Antraciclinas/efeitos adversos , Antibióticos Antineoplásicos/efeitos adversos , Cardiomiopatias/induzido quimicamente , Cardiomiopatias/complicações , Cardiomiopatias/genética , Cardiotoxicidade/etiologia , Causalidade , Conectina/genética , Humanos , Masculino
7.
Circulation ; 139(1): 37-47, 2019 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-30586701

RESUMO

BACKGROUND: Secondary mitral regurgitation (SMR) occurs in the absence of organic mitral valve disease and may develop as the left ventricle dilates or remodels or as a result of leaflet tethering with impaired coaptation, most commonly from apical and lateral distraction of the subvalvular apparatus, with late annular dilatation. The optimal therapy for SMR is unclear. This study sought to evaluate the 1-year adjudicated outcomes of all patients with SMR undergoing the MitraClip procedure in the EVEREST II (Endovascular Valve Edge-to-Edge Repair Study) Investigational Device Exemption program, which is comprised of the randomized clinical trial, the prospective High-Risk Registry, and the REALISM Continued Access Registry (Multicenter Study of the MitraClip System). METHODS: Patients with 3+/4+ SMR enrolled in EVEREST II were stratified by non-high surgical risk (non-HR) and high surgical risk (HR) status (defined as Society of Thoracic Surgeons risk of mortality ≥12% or predefined risk factors). Clinical, echocardiographic, and functional outcomes at 1 year were evaluated. RESULTS: A total of 616 patients (482 HR, 134 non-HR; mean age, 73.3±10.5 years; Society of Thoracic Surgeons risk, 10.2±6.9%) with SMR underwent the MitraClip procedure. At baseline, 80.5% of patients were in New York Heart Association class III/IV. Major adverse events at 30 days included death (3.6%), stroke (2.3%), and renal failure (1.5%). At discharge, 88.8% had MR ≤2+. At 1 year, there were 139 deaths, and the Kaplan-Meier estimate of freedom from mortality was 76.8%. The majority of surviving patients (84.7%) remained with MR ≤2+ and New York Heart Association class I/II (83.0%). Kaplan-Meier survival at 1 year was 74.1% in HR patients and 86.4% in non-HR patients ( P=0.0175). At 1 year, both groups achieved comparable MR reduction (MR ≤2+, 84.0% versus 87.0%) and improvement in left ventricular end-diastolic volume (-8.0 mL versus -12.7 mL), whereas New York Heart Association class I/II was found in 80.1% versus 91.8% ( P=0.008) of HR and non-HR patients, respectively. In HR patients, the annualized rate of heart failure hospitalizations decreased from 0.68 to 0.46 in the 12 months before to 12 months after the procedure ( P<0.0001). CONCLUSIONS: Transcatheter mitral valve repair with the MitraClip in patients with secondary MR is associated with acceptable safety, reduction of MR severity, symptom improvement, and positive ventricular remodeling. CLINICAL TRIAL REGISTRATION: https://www.clinicaltrials.gov . Unique identifiers: NCT00209274, NCT01940120, and NCT01931956.


Assuntos
Cateterismo Cardíaco/instrumentação , Implante de Prótese de Valva Cardíaca/instrumentação , Próteses Valvulares Cardíacas , Insuficiência da Valva Mitral/cirurgia , Valva Mitral/cirurgia , Idoso , Idoso de 80 Anos ou mais , Cateterismo Cardíaco/efeitos adversos , Cateterismo Cardíaco/mortalidade , Ecocardiografia Transesofagiana , Feminino , Implante de Prótese de Valva Cardíaca/efeitos adversos , Implante de Prótese de Valva Cardíaca/mortalidade , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Valva Mitral/diagnóstico por imagem , Valva Mitral/fisiopatologia , Insuficiência da Valva Mitral/diagnóstico por imagem , Insuficiência da Valva Mitral/mortalidade , Insuficiência da Valva Mitral/fisiopatologia , Complicações Pós-Operatórias/etiologia , Estudos Prospectivos , Desenho de Prótese , Recuperação de Função Fisiológica , Sistema de Registros , Medição de Risco , Fatores de Risco , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento
8.
Mol Pharm ; 14(7): 2307-2313, 2017 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-28505463

RESUMO

A novel pretargeted SPECT imaging strategy based on the HaloTag enzyme has been evaluated for the first time in a living system. To determine the efficacy of this approach, two clinically relevant cancer biomarkers, HER2 and TAG-72, were selected to represent models of internalizing and noninternalizing antigens, respectively. In MDA-MB-231/H2N (HER2-expressing) and LS174T (TAG-72-expressing) xenograft tumors in mice, pretargeting experiments were performed in which HaloTag-conjugated derivatives of the antibodies trastuzumab (anti-HER2) or CC49 (anti-TAG-72) were utilized as primary agents, and the small molecule HaloTag ligands 111In-HTL-1, -2, and -3 were evaluated as secondary agents. While this approach was not sufficiently sensitive to detect the internalizing HER2 antigen, pretargeting experiments involving the most optimal secondary agent, 111In-HTL-3, were successful in detecting the noninternalizing antigen TAG-72 and provided high-contrast SPECT images at 4 and 24 h postinjection.


Assuntos
Antígenos de Neoplasias/metabolismo , Glicoproteínas/metabolismo , Receptor ErbB-2/metabolismo , Animais , Linhagem Celular Tumoral , Feminino , Xenoenxertos , Humanos , Radioisótopos de Índio/análise , Camundongos , Radioimunoterapia , Tomografia Computadorizada de Emissão de Fóton Único
9.
Nano Lett ; 16(1): 549-54, 2016 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-26691496

RESUMO

During the discharge of a lithium-sulfur (Li-S) battery, an electronically insulating 2D layer of Li2S is electrodeposited onto the current collector. Once the current collector is enveloped, the overpotential of the cell increases, and its discharge is arrested, often before reaching the full capacity of the active material. Guided by a new computational platform known as the Electrolyte Genome, we advance and apply benzo[ghi]peryleneimide (BPI) as a redox mediator for the reduction of dissolved polysulfides to Li2S. With BPI present, we show that it is now possible to electrodeposit Li2S as porous, 3D deposits onto carbon current collectors during cell discharge. As a result, sulfur utilization improved 220% due to a 6-fold increase in Li2S formation. To understand the growth mechanism, electrodeposition of Li2S was carried out under both galvanostatic and potentiostatic control. The observed kinetics under potentiostatic control were modeled using modified Avrami phase transformation kinetics, which showed that BPI slows the impingement of insulating Li2S islands on carbon. Conceptually, the pairing of conductive carbons with BPI can be viewed as a vascular approach to the design of current collectors for energy storage devices: here, conductive carbon "arteries" dominate long-range electron transport, while BPI "capillaries" mediate short-range transport and electron transfer between the storage materials and the carbon electrode.

10.
Anal Biochem ; 489: 1-8, 2015 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-26278171

RESUMO

Ligand-mediated endocytosis is a key autoregulatory mechanism governing the duration and intensity of signals emanating from cell surface receptors. Due to the mechanistic complexity of endocytosis and its emerging relevance in disease, simple methods capable of tracking this dynamic process in cells have become increasingly desirable. We have developed a bioluminescent reporter technology for real-time analysis of ligand-mediated receptor endocytosis using genetic fusions of NanoLuc luciferase with various G-protein-coupled receptors (GPCRs). This method is compatible with standard microplate formats, which should decrease work flows for high-throughput screens. This article also describes the application of this technology to endocytosis of epidermal growth factor receptor (EGFR), demonstrating potential applicability of the method beyond GPCRs.


Assuntos
Proteínas de Artrópodes/metabolismo , Endocitose , Ensaios de Triagem em Larga Escala/métodos , Luciferases/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Animais , Proteínas de Artrópodes/química , Proteínas de Artrópodes/genética , Membrana Celular/efeitos dos fármacos , Membrana Celular/enzimologia , Membrana Celular/metabolismo , Descoberta de Drogas/métodos , Endocitose/efeitos dos fármacos , Corantes Fluorescentes/química , Genes Reporter/efeitos dos fármacos , Células HEK293 , Humanos , Interleucina-6/química , Interleucina-6/genética , Interleucina-6/metabolismo , Cinética , Ligantes , Luciferases/química , Luciferases/genética , Microscopia Confocal , Microscopia de Fluorescência , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Sinais Direcionadores de Proteínas/efeitos dos fármacos , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/genética , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo
11.
Nano Lett ; 14(4): 2210-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24597525

RESUMO

A new approach to flow battery design is demonstrated wherein diffusion-limited aggregation of nanoscale conductor particles at ∼1 vol % concentration is used to impart mixed electronic-ionic conductivity to redox solutions, forming flow electrodes with embedded current collector networks that self-heal after shear. Lithium polysulfide flow cathodes of this architecture exhibit electrochemical activity that is distributed throughout the volume of flow electrodes rather than being confined to surfaces of stationary current collectors. The nanoscale network architecture enables cycling of polysulfide solutions deep into precipitation regimes that historically have shown poor capacity utilization and reversibility and may thereby enable new flow battery designs of higher energy density and lower system cost. Lithium polysulfide half-flow cells operating in both continuous and intermittent flow mode are demonstrated for the first time.

12.
Nat Hum Behav ; 8(5): 988-1000, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38438651

RESUMO

People who take on challenges and persevere longer are more likely to succeed in life. But individuals often avoid exerting effort, and there is limited experimental research investigating whether we can learn to value effort. We developed a paradigm to test the hypothesis that people can learn to value effort and will seek effortful challenges if directly incentivized to do so. We also dissociate the effects of rewarding people for choosing effortful challenges and performing well. The results provide limited evidence that rewarding effort increased people's willingness to choose harder tasks when rewards were no longer offered (near transfer). There was also mixed evidence that rewarding effort increased willingness to choose harder tasks in another unrelated and unrewarded task (far transfer). These heterogeneous results highlight the need for further research to understand when this paradigm may be the most effective for increasing and generalizing the value of effort.


Assuntos
Motivação , Recompensa , Humanos , Masculino , Feminino , Adulto , Adulto Jovem , Comportamento de Escolha , Transferência de Experiência
13.
Antimicrob Agents Chemother ; 57(7): 2929-36, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23571548

RESUMO

Inhibitors of peptide deformylase (PDF) represent a new class of antibacterial agents with a novel mechanism of action. Mutations that inactivate formyl methionyl transferase (FMT), the enzyme that formylates initiator methionyl-tRNA, lead to an alternative initiation of protein synthesis that does not require deformylation and are the predominant cause of resistance to PDF inhibitors in Staphylococcus aureus. Here, we report that loss-of-function mutations in FMT impart pleiotropic effects that include a reduced growth rate, a nonhemolytic phenotype, and a drastic reduction in production of multiple extracellular proteins, including key virulence factors, such as α-hemolysin and Panton-Valentine leukocidin (PVL), that have been associated with S. aureus pathogenicity. Consequently, S. aureus FMT mutants are greatly attenuated in neutropenic and nonneutropenic murine pyelonephritis infection models and show very high survival rates compared with wild-type S. aureus. These newly discovered effects on extracellular virulence factor production demonstrate that FMT-null mutants have a more severe fitness cost than previously anticipated, leading to a substantial loss of pathogenicity and a restricted ability to produce an invasive infection.


Assuntos
Farmacorresistência Bacteriana/genética , Hidroximetil e Formil Transferases/genética , Staphylococcus aureus/enzimologia , Staphylococcus aureus/genética , Amidoidrolases/antagonistas & inibidores , Animais , Antibacterianos/farmacologia , Toxinas Bacterianas/biossíntese , Toxinas Bacterianas/genética , Exotoxinas/biossíntese , Exotoxinas/genética , Proteínas Hemolisinas/biossíntese , Proteínas Hemolisinas/genética , Leucocidinas/biossíntese , Leucocidinas/genética , Masculino , Camundongos , Camundongos Endogâmicos CBA , Testes de Sensibilidade Microbiana , Pielonefrite/microbiologia , Infecções Estafilocócicas , Staphylococcus aureus/patogenicidade , Fatores de Virulência
14.
Phys Chem Chem Phys ; 15(38): 15833-9, 2013 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-23995625

RESUMO

An aqueous Li-ion flow cell using suspension-based flow electrodes based on the LiTi2(PO4)3-LiFePO4 couple is demonstrated. Unlike conventional flow batteries, the semi-solid approach utilizes fluid electrodes that are electronically conductive. A model of simultaneous advection and electrochemical transport is developed and used to separate flow-induced losses from those due to underlying side reactions. The importance of plug flow to achieving high energy efficiency in flow batteries utilizing highly non-Newtonian flow electrodes is emphasized.

15.
J Immunother ; 46(3): 96-106, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36809225

RESUMO

T-cell immunotherapies are promising strategies to generate T-cell responses towards tumor-derived or pathogen-derived antigens. Adoptive transfer of T cells genetically modified to express antigen receptor transgenes has shown promise for the treatment of cancer. However, the development of T-cell redirecting therapies relies on the use of primary immune cells and is hampered by the lack of easy-to-use model systems and sensitive readouts to facilitate candidate screening and development. Particularly, testing T-cell receptor (TCR)-specific responses in primary T cells and immortalized T cells is confounded by the presence of endogenous TCR expression which results in mixed alpha/beta TCR pairings and compresses assay readouts. Herein, we describe the development of a novel cell-based TCR knockout (TCR-KO) reporter assay platform for the development and characterization of T-cell redirecting therapies. CRISPR/Cas9 was used to knockout the endogenous TCR chains in Jurkat cells stably expressing a human interleukin-2 promoter-driven luciferase reporter gene to measure TCR signaling. Reintroduction of a transgenic TCR into the TCR-KO reporter cells results in robust antigen-specific reporter activation compared with parental reporter cells. The further development of CD4/CD8 double-positive and double-negative versions enabled low-avidity and high-avidity TCR screening with or without major histocompatibility complex bias. Furthermore, stable TCR-expressing reporter cells generated from TCR-KO reporter cells exhibit sufficient sensitivity to probe in vitro T-cell immunogenicity of protein and nucleic acid-based vaccines. Therefore, our data demonstrated that TCR-KO reporter cells can be a useful tool for the discovery, characterization, and deployment of T-cell immunotherapy.


Assuntos
Receptores de Antígenos de Linfócitos T alfa-beta , Receptores de Antígenos de Linfócitos T , Humanos , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Transferência Adotiva , Luciferases , Desenvolvimento de Vacinas
16.
Disabil Rehabil Assist Technol ; : 1-8, 2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-37971205

RESUMO

PURPOSE: Rehabilitation professionals prescribe patients with suitable powered mobility aids (PMAs) based on patient characteristics, e.g., age and mobility. However, there is paucity of literature examining patient characteristics associated with PMA types in Asian contexts. This research aims to study (i) characteristics of Singapore PMA users and (ii) correlations between characteristics and two PMA types - motorised wheelchairs and powered scooters. It is hypothesised that patients' age, mobility status and medical conditions have correlations with PMA types. METHODOLOGY: A cross-sectional, retrospective study design was used to investigate characteristics of patients (age ≥ 21 years) at Tan Tock Seng Hospital Occupational Therapy Seating Clinic between 2017 and 2019. Comparisons of proportions of motorised wheelchair users versus powered scooter users based on characteristics were analysed using Chi-square test. Subsequently, statistically significant patient characteristics were selected for a multiple logistic regression. RESULTS: Among 352 patients, 21% and 79% were prescribed motorised wheelchairs and powered scooters, respectively. Patients aged 61-90 years were twice those aged 21-60 years. Males were double of females. Patients of (i) an older age, (ii) more ambulant, (iii) independent in transfers and (iv) in activities of daily living (ADLs), were more likely powered scooter users. Conversely, patients of (i) a younger age, (ii) less ambulant, (iii) require assistance in transfers and (iv) in ADLs were more likely motorised wheelchair users. Patients' gender and caregiver status showed no statistically significant correlations with PMA types. CONCLUSIONS: Rehabilitation professionals could consider patients' age, mobility status, transfer status and ADL status when prescribing PMA for Asian populations.Implications for rehabilitationGuide rehabilitation professionals in making clinical decisions on the type of powered mobility aid (PMA) to prescribe based on patients' characteristics.Aid in the development of future guidelines for rehabilitation professionals in prescription of PMAs.

17.
Eur J Cancer Prev ; 31(1): 82-84, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33369951

RESUMO

There is currently no evidence of the carcinogenic effect of the ß-adrenergic agonist ractopamine added in finishing swine and cattle feed for promoting leanness. Nonetheless, it has the capability of stimulating expression of asparagine synthetase (ASNS) through activating transcription factor 5, and many other genes involved in the stress reaction in the skeletal muscle of pigs according to published scientific articles. Because overexpression of ASNS has been detected as a key player in amino acid response and unfolded protein response during the development of not a few malignant diseases, especially those with KRAS mutations, and found to be closely related to tumor proliferation, invasion and metastasis, it seems reasonable to hypothesize that intake of ractopamine residue in meat might bring negative effects to cancer patients.


Assuntos
Aspartato-Amônia Ligase , Neoplasias , Animais , Aspartato-Amônia Ligase/genética , Aspartato-Amônia Ligase/metabolismo , Bovinos , Humanos , Carne , Neoplasias/genética , Fenetilaminas/farmacologia , Suínos
18.
Cureus ; 14(4): e24193, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35592216

RESUMO

A 39-year-old man with a history of intravenous drug use was diagnosed to have a sudden onset of immune thrombocytopenia (ITP) in the background of a chronic hepatitis C infection with genotype 3a. Two courses of high-dose pulse dexamethasone therapy (40 mg daily for consecutive four days) failed to raise the platelet counts, but a combination direct-acting antiviral (DAA) regimen of sofosbuvir and velpatasvir, which had been proved to be effective for all hepatitis C virus (HCV) genotypes, successfully restored the platelets number to normal ranges after hepatitis C virus ribonucleic acid (RNA) was totally eliminated. Molecular mimicry of hepatitis C virus envelope proteins with platelet surface antigens is proposed to be the underlying cause of immune thrombocytopenia. An adequate direct-acting antiviral regimen is considered to be the most reliable therapy for hepatitis C-related immune thrombocytopenia.

19.
J Med Case Rep ; 16(1): 459, 2022 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-36496425

RESUMO

BACKGROUND: Multiple myeloma remains incurable despite treatment advancements over the last 20 years. LCAR-B38M Cells in Treating Relapsed/Refractory Multiple Myeloma was a phase 1, first-in-human, investigator-initiated study in relapsed/refractory multiple myeloma conducted at four sites in China. The study used LCAR-B38M chimeric antigen receptor-T cells expressing two B-cell maturation antigen-targeting single-domain antibodies designed to confer avidity, and a CD3ζ signaling domain with a 4-1BB costimulatory domain to optimize T-cell activation and proliferation. This chimeric antigen receptor construct is identical to ciltacabtagene autoleucel. In the LEGEND-2 study (n = 57, Xi'an site), overall response rate was 88%; median (95% CI) progression-free survival and overall survival were 19.9 (9.6-31.0) and 36.1 (26.4-not evaluable) months, respectively; and median follow-up was 25 months. This case study reports on a patient with relapsed/refractory multiple myeloma (λ light chain type) who was treated with LCAR-B38M chimeric antigen receptor T cells in the LEGEND-2 study (Xi'an site); he had received five prior lines of treatment and had extensive extramedullary lesions. CASE PRESENTATION: The patient, a 56-year-old Asian male, received cyclophosphamide (500 mg daily × 3 days) as lymphodepletion therapy and a total dose of 0.5 × 106 chimeric antigen receptor + T cells/kg split into three infusions (days 1, 24, and 84 from June to August 2016). He experienced grade 2 cytokine release syndrome after the first infusion; all symptoms resolved with treatment. No cytokine release syndrome occurred following the second and third infusions. His λ light chain levels decreased and normalized 20 days after the first infusion, and extramedullary lesions were healed as of January 2018. He has sustained remission for 5 years and received no other multiple myeloma treatments after LCAR-B38M chimeric antigen receptor T cell infusion. As of 30 October 2020, the patient is still progression-free and has maintained minimal residual disease-negative (10-4) complete response status for 52 months. CONCLUSIONS: This case provides support that treatment with LCAR-B38M chimeric antigen receptor T cells can result in long-term disease remission of 5 or more years without disease progression in a heavily pretreated patient with extensive extramedullary disease and no other treatment options.


Assuntos
Mieloma Múltiplo , Receptores de Antígenos Quiméricos , Masculino , Humanos , Pessoa de Meia-Idade , Receptores de Antígenos Quiméricos/uso terapêutico , Mieloma Múltiplo/tratamento farmacológico , Antígeno de Maturação de Linfócitos B , Linfócitos T/patologia , Progressão da Doença
20.
Dement Geriatr Cogn Dis Extra ; 11(2): 110-113, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34178014

RESUMO

The feed additive ractopamine, a ß-adrenergic agonist, has been approved for use in livestock for nearly 2 decades. Studies of its possible adverse effects in humans have concentrated exclusively on cardiovascular disease and cardiovascular functional disorders in the past. In this article, whether and how ractopamine may affect neurodegeneration, either to promote or to reduce the incidence of Alz-heimer disease, will be discussed based on the recent controversial findings that ß-adrenoreceptor activation not only can stimulate Alzheimer-pathogenic amyloid-ß accumulation but also are able to enhance hippocampal neurogenesis and ameliorate mouse memory deficits in independent laboratory studies. Furthermore, environmental enrichment has been found to prevent impairment of memory-related hippocampal long-term potentiation and microglia-mediated neuroinflammation induced by amyloid-ß. These beneficial effects are achieved mainly through enhanced ß-adrenergic signaling and can be imitated by ß agonist isoprotenerol. Finally, it has been demonstrated that the ß-adrenergic agonist salbutamol could bind directly to tau protein and interfere with the tau filament formation seen in the prodromal phase of Alzheimer disease. These complex but interesting issues lead to contradictory speculations of possible effects of ractopamine residue in meat on Alzheimer disease. Hypotheses derived from this review surely deserve carefully designed laboratory investigations and clinical studies in the future.

SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa