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1.
Cell ; 181(7): 1566-1581.e27, 2020 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-32531200

RESUMO

The accurate timing and execution of organelle biogenesis is crucial for cell physiology. Centriole biogenesis is regulated by Polo-like kinase 4 (Plk4) and initiates in S-phase when a daughter centriole grows from the side of a pre-existing mother. Here, we show that a Plk4 oscillation at the base of the growing centriole initiates and times centriole biogenesis to ensure that centrioles grow at the right time and to the right size. The Plk4 oscillation is normally entrained to the cell-cycle oscillator but can run autonomously of it-potentially explaining why centrioles can duplicate independently of cell-cycle progression. Mathematical modeling indicates that the Plk4 oscillation can be generated by a time-delayed negative feedback loop in which Plk4 inactivates the interaction with its centriolar receptor through multiple rounds of phosphorylation. We hypothesize that similar organelle-specific oscillations could regulate the timing and execution of organelle biogenesis more generally.


Assuntos
Relógios Biológicos/fisiologia , Centríolos/metabolismo , Proteínas de Drosophila/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Ciclo Celular/fisiologia , Proteínas de Ciclo Celular/metabolismo , Centrossomo/metabolismo , Proteínas de Drosophila/fisiologia , Drosophila melanogaster/metabolismo , Biogênese de Organelas , Fosforilação , Proteínas Serina-Treonina Quinases/fisiologia
2.
Annu Rev Cell Dev Biol ; 36: 191-218, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-32663035

RESUMO

Neutrophils are critical to innate immunity, including host defense against bacterial and fungal infections. They achieve their host defense role by phagocytosing pathogens, secreting their granules full of cytotoxic enzymes, or expelling neutrophil extracellular traps (NETs) during the process of NETosis. NETs are weblike DNA structures decorated with histones and antimicrobial proteins released by activated neutrophils. Initially described as a means for neutrophils to neutralize pathogens, NET release also occurs in sterile inflammation, promotes thrombosis, and can mediate tissue damage. To effectively manipulate this double-edged sword to fight a particular disease, researchers must work toward understanding the mechanisms driving NETosis. Such understanding would allow the generation of new drugs to promote or prevent NETosis as needed. While knowledge regarding the (patho)physiological roles of NETosis is accumulating, little is known about the cellular and biophysical bases of this process. In this review, we describe and discuss our current knowledge of the molecular, cellular, and biophysical mechanisms mediating NET release as well as open questions in the field.


Assuntos
Armadilhas Extracelulares/metabolismo , Animais , Membrana Celular/metabolismo , Núcleo Celular/metabolismo , Citoesqueleto/metabolismo , Citosol/metabolismo , DNA/metabolismo , Humanos
3.
EMBO J ; 43(3): 414-436, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38233576

RESUMO

Mitotic centrosomes assemble when centrioles recruit large amounts of pericentriolar material (PCM) around themselves. In early C. elegans embryos, mitotic centrosome size appears to be set by the limiting amount of a key component. In Drosophila syncytial embryos, thousands of mitotic centrosomes are assembled as the embryo proceeds through 13 rounds of rapid nuclear division, driven by a core cell cycle oscillator. These divisions slow during nuclear cycles 11-13, and we find that centrosomes respond by reciprocally decreasing their growth rate, but increasing their growth period-so that they grow to a relatively consistent size at each cycle. At the start of each cycle, moderate CCO activity initially promotes centrosome growth, in part by stimulating Polo/PLK1 recruitment to centrosomes. Later in each cycle, high CCO activity inhibits centrosome growth by suppressing the centrosomal recruitment and/or maintenance of centrosome proteins. Thus, in fly embryos, mitotic centrosome size appears to be regulated predominantly by the core cell cycle oscillator, rather than by the depletion of a limiting component.


Assuntos
Proteínas de Drosophila , Drosophila , Animais , Drosophila/metabolismo , Caenorhabditis elegans/metabolismo , Centrossomo/metabolismo , Centríolos/metabolismo , Ciclo Celular , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Mitose
4.
EMBO J ; 41(11): e110891, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35505659

RESUMO

Mitotic centrosomes are formed when centrioles start to recruit large amounts of pericentriolar material (PCM) around themselves in preparation for mitosis. This centrosome "maturation" requires the centrioles and also Polo/PLK1 protein kinase. The PCM comprises several hundred proteins and, in Drosophila, Polo cooperates with the conserved centrosome proteins Spd-2/CEP192 and Cnn/CDK5RAP2 to assemble a PCM scaffold around the mother centriole that then recruits other PCM client proteins. We show here that in Drosophila syncytial blastoderm embryos, centrosomal Polo levels rise and fall during the assembly process-peaking, and then starting to decline, even as levels of the PCM scaffold continue to rise and plateau. Experiments and mathematical modelling indicate that a centriolar pulse of Polo activity, potentially generated by the interaction between Polo and its centriole receptor Ana1 (CEP295 in humans), could explain these unexpected scaffold assembly dynamics. We propose that centrioles generate a local pulse of Polo activity prior to mitotic entry to initiate centrosome maturation, explaining why centrioles and Polo/PLK1 are normally essential for this process.


Assuntos
Centríolos , Proteínas de Drosophila , Animais , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Centríolos/metabolismo , Centrossomo/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Mitose , Proteínas Serina-Treonina Quinases/genética
5.
Proc Natl Acad Sci U S A ; 120(28): e2301153120, 2023 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-37399422

RESUMO

Night-migratory songbirds have a light-dependent magnetic compass sense, the mechanism of which is thought to depend on the photochemical formation of radical pairs in cryptochrome (Cry) proteins located in the retina. The finding that weak radiofrequency (RF) electromagnetic fields can prevent birds from orienting in the Earth's magnetic field has been regarded as a diagnostic test for this mechanism and as a potential source of information on the identities of the radicals. The maximum frequency that could cause such disorientation has been predicted to lie between 120 and 220 MHz for a flavin-tryptophan radical pair in Cry. Here we show that the magnetic orientation capabilities of Eurasian blackcaps (Sylvia atricapilla) are not affected by RF noise in the frequency bands 140 to 150 MHz and 235 to 245 MHz. From a consideration of its internal magnetic interactions, we argue that RF field effects on a flavin-containing radical-pair sensor should be approximately independent of frequency up to 116 MHz and that birds' sensitivity to RF disorientation should fall by about two orders of magnitude when the frequency exceeds 116 MHz. Taken together with our earlier finding that 75 to 85 MHz RF fields disrupt the magnetic orientation of blackcaps, these results provide compelling evidence that the magnetic compass of migratory birds operates by a radical pair mechanism.


Assuntos
Aves Canoras , Resposta Táctica , Animais , Aves Canoras/metabolismo , Processos Fotoquímicos , Migração Animal , Campos Magnéticos , Criptocromos/metabolismo
6.
Nano Lett ; 24(36): 11210-11216, 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39054892

RESUMO

Lipids and nucleic acids are two of the most abundant components of our cells, and both molecules are widely used as engineering materials for nanoparticles. Here, we present a systematic study of how hydrophobic modifications can be employed to modulate the DNA/lipid interface. Using a series of DNA anchors with increasing hydrophobicity, we quantified the capacity to immobilize double-stranded (ds) DNA to lipid membranes in the liquid phase. Contrary to electrostatic effects, hydrophobic anchors are shown to be phase-independent if sufficiently hydrophobic. For weak anchors, the overall hydrophobicity can be enhanced following the concept of multivalency. Finally, we demonstrate that structural flexibility and anchor orientation overrule the effect of multivalency, emphasizing the need for careful scaffold design if strong interfaces are desired. Together, our findings guide the design of tailored DNA/membrane interfaces, laying the groundwork for advancements in biomaterials, drug delivery vehicles, and synthetic membrane mimics for biomedical research and nanomedicine.


Assuntos
DNA , Interações Hidrofóbicas e Hidrofílicas , DNA/química , Lipídeos/química , Bicamadas Lipídicas/química , Eletricidade Estática , Propriedades de Superfície
7.
Biochemistry ; 63(17): 2131-2140, 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39175413

RESUMO

Phototransduction in vertebrate photoreceptor cells is controlled by Ca2+-dependent feedback loops involving the membrane-bound guanylate cyclase GC-E that synthesizes the second messenger guanosine-3',5'-cyclic monophosphate. Intracellular Ca2+-sensor proteins named guanylate cyclase-activating proteins (GCAPs) regulate the activity of GC-E by switching from a Ca2+-bound inhibiting state to a Ca2+-free/Mg2+-bound activating state. The gene GUCY2D encodes for human GC-E, and mutations in GUCY2D are often associated with an imbalance of Ca2+ and cGMP homeostasis causing retinal disorders. Here, we investigate the Ca2+-dependent inhibition of the constitutively active GC-E mutant V902L. The inhibition is not mediated by GCAP variants but by Ca2+ replacing Mg2+ in the catalytic center. Distant from the cyclase catalytic domain is an α-helical domain containing a highly conserved helix-turn-helix motif. Mutating the critical amino acid position 804 from leucine to proline left the principal activation mechanism intact but resulted in a lower level of catalytic efficiency. Our experimental analysis of amino acid positions in two distant GC-E domains implied an allosteric communication pathway connecting the α-helical and the cyclase catalytic domains. A computational connectivity analysis unveiled critical differences between wildtype GC-E and the mutant V902L in the allosteric network of critical amino acid positions.


Assuntos
Domínio Catalítico , Guanilato Ciclase , Regulação Alostérica , Guanilato Ciclase/metabolismo , Guanilato Ciclase/química , Guanilato Ciclase/genética , Animais , Cálcio/metabolismo , Proteínas Ativadoras de Guanilato Ciclase/metabolismo , Proteínas Ativadoras de Guanilato Ciclase/química , Proteínas Ativadoras de Guanilato Ciclase/genética , Humanos , Multimerização Proteica , Magnésio/metabolismo , Camundongos , Células Fotorreceptoras de Vertebrados/metabolismo , Receptores de Superfície Celular/metabolismo , Receptores de Superfície Celular/química , Receptores de Superfície Celular/genética
8.
J Cell Sci ; 135(14)2022 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-35707992

RESUMO

Centrioles are composed of a central cartwheel tethered to nine-fold symmetric microtubule (MT) blades. The centriole cartwheel and MTs are thought to grow from opposite ends of these organelles, so it is unclear how they coordinate their assembly. We previously showed that in Drosophila embryos an oscillation of Polo-like kinase 4 (Plk4) helps to initiate and time the growth of the cartwheel at the proximal end. Here, in the same model, we show that CP110 and Cep97 form a complex close to the distal-end of the centriole MTs whose levels rise and fall as the new centriole MTs grow, in a manner that appears to be entrained by the core cyclin-dependent kinase (Cdk)-Cyclin oscillator that drives the nuclear divisions in these embryos. These CP110 and Cep97 dynamics, however, do not appear to time the period of centriole MT growth directly. Instead, we find that changing the levels of CP110 and Cep97 appears to alter the Plk4 oscillation and the growth of the cartwheel at the proximal end. These findings reveal an unexpected potential crosstalk between factors normally concentrated at opposite ends of the growing centrioles, which might help to coordinate centriole growth. This article has an associated First Person interview with the first authors of the paper.


Assuntos
Centríolos , Proteínas Associadas aos Microtúbulos , Fosfoproteínas/metabolismo , Animais , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Centríolos/metabolismo , Drosophila/metabolismo , Humanos , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Microtúbulos/metabolismo , Proteínas Serina-Treonina Quinases/genética
9.
Am J Gastroenterol ; 119(7): 1318-1325, 2024 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-38305278

RESUMO

INTRODUCTION: Both artificial intelligence (AI) and distal attachment devices have been shown to improve adenoma detection rate and reduce miss rate during colonoscopy. We studied the combined effect of Endocuff and AI on enhancing detection rates of various colonic lesions. METHODS: This was a 3-arm prospective randomized colonoscopy study involving patients aged 40 years or older. Participants were randomly assigned in a 1:1:1 ratio to undergo Endocuff with AI, AI alone, or standard high-definition (HD) colonoscopy. The primary outcome was adenoma detection rate (ADR) between the Endocuff-AI and AI groups while secondary outcomes included detection rates of polyp (PDR), sessile serrated lesion (sessile detection rate [SDR]), and advanced adenoma (advanced adenoma detection rate) between the 2 groups. RESULTS: A total of 682 patients were included (mean age 65.4 years, 52.3% male), with 53.7% undergoing diagnostic colonoscopy. The ADR for the Endocuff-AI, AI, and HD groups was 58.7%, 53.8%, and 46.3%, respectively, while the corresponding PDR was 77.0%, 74.0%, and 61.2%. A significant increase in ADR, PDR, and SDR was observed between the Endocuff-AI and AI groups (ADR difference: 4.9%, 95% CI: 1.4%-8.2%, P = 0.03; PDR difference: 3.0%, 95% CI: 0.4%-5.8%, P = 0.04; SDR difference: 6.4%, 95% CI: 3.4%-9.7%, P < 0.01). Both Endocuff-AI and AI groups had a higher ADR, PDR, SDR, and advanced adenoma detection rate than the HD group (all P < 0.01). DISCUSSION: Endocuff in combination with AI further improves various colonic lesion detection rates when compared with AI alone.


Assuntos
Adenoma , Inteligência Artificial , Colonoscopia , Neoplasias Colorretais , Humanos , Colonoscopia/métodos , Masculino , Feminino , Adenoma/diagnóstico , Adenoma/diagnóstico por imagem , Idoso , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/diagnóstico por imagem , Pessoa de Meia-Idade , Estudos Prospectivos , Pólipos do Colo/diagnóstico , Pólipos do Colo/diagnóstico por imagem , Adulto
10.
Exp Dermatol ; 33(3): e15060, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38532576

RESUMO

Psoriatic arthritis (PsA) is a major comorbidity of psoriasis and may lead to irreversible joint damage and disability. This study aims to describe the clinical profile, treatment and quality of life (QoL) of patients with PsA in Malaysia. This is a multicentre retrospective cross-sectional study of psoriasis patients who were notified to the Malaysian Psoriasis Registry (MPR) from January 2007 to December 2018. Of 21 735 psoriasis patients, 2756 (12.7%) had PsA. The male to female ratio was 1:1. The mean age of psoriasis onset for PsA patients was 34.73 ± 14.44 years. They had a higher rate of family history of psoriasis (26% vs. 22.4%, p < 0.001), scalp (82.7% vs. 81.0%, p = 0.04) and nail involvement (73.3% vs. 53.3%, p < 0.001), obesity (62.6% vs. 54.4%, p < 0.001), dyslipidaemia (23.8% vs. 15.4%, p < 0.001), hypertension (31.1% vs. 22.7%, p < 0.001) and diabetes mellitus (20.9% vs. 15.2%, p < 0.001) compared to non-PsA patients. More than half (54.3%) had severe psoriasis [(body surface area >10% and/or Dermatology Life Quality Index (DLQI) >10)]. Most had oligo-/monoarthropathy (40.3%), followed by distal interphalangeal arthropathy (31.3%), symmetrical polyarthropathy (28.3%), spondylitis/sacroiliitis (8.2%) and arthritis mutilans (3.2%). Nearly 40% of PsA patients received systemic treatment, but only 1.6% received biologic agents. QoL was more significantly affected in PsA than in non-PsA patients (mean DLQI 10.12 ± 7.16 vs. 9.52 ± 6.67, p < 0.001). One in eight patients with psoriasis in Malaysia had PsA. They had a higher incidence of comorbidities, severe disease, impaired QoL and were more likely to receive systemic and biological treatment compared to non PsA patients.


Assuntos
Artrite Psoriásica , Psoríase , Humanos , Masculino , Feminino , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Artrite Psoriásica/epidemiologia , Qualidade de Vida , Estudos Transversais , Malásia , Estudos Retrospectivos , Psoríase/epidemiologia
11.
FASEB J ; 37(7): e23009, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37273180

RESUMO

Human and animal studies support that consuming a high level of linoleic acid (LA, 18:2ω-6), an essential fatty acid and key component of the human diet, increases the risk of colon cancer. However, results from human studies have been inconsistent, making it challenging to establish dietary recommendations for optimal LA intake. Given the importance of LA in the human diet, it is crucial to better understand the molecular mechanisms underlying its potential colon cancer-promoting effects. Using LC-MS/MS-based targeted lipidomics, we find that the cytochrome P450 (CYP) monooxygenase pathway is a major pathway for LA metabolism in vivo. Furthermore, CYP monooxygenase is required for the colon cancer-promoting effects of LA, since the LA-rich diet fails to exacerbate colon cancer in CYP monooxygenase-deficient mice. Finally, CYP monooxygenase mediates the pro-cancer effects of LA by converting LA to epoxy octadecenoic acids (EpOMEs), which have potent effects on promoting colon tumorigenesis via gut microbiota-dependent mechanisms. Overall, these results support that CYP monooxygenase-mediated conversion of LA to EpOMEs plays a crucial role in the health effects of LA, establishing a unique mechanistic link between dietary fatty acid intake and cancer risk. These results could help in developing more effective dietary guidelines for optimal LA intake and identifying subpopulations that may be especially vulnerable to LA's negative effects.


Assuntos
Neoplasias do Colo , Ácido Linoleico , Humanos , Camundongos , Animais , Ácido Linoleico/farmacologia , Ácido Linoleico/metabolismo , Cromatografia Líquida , Espectrometria de Massas em Tandem , Eicosanoides , Sistema Enzimático do Citocromo P-450/metabolismo , Dieta , Neoplasias do Colo/etiologia
12.
Chemphyschem ; : e202400129, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38668824

RESUMO

This study explores the impact of thermal motion on the magnetic compass mechanism in migratory birds, focusing on the radical pair mechanism within cryptochrome photoreceptors. The coherence of radical pairs, crucial for magnetic field inference, is curbed by spin relaxation induced by intra-protein motion. Molecular dynamics simulations, density-functional-theory-based calculations, and spin dynamics calculations were employed, utilizing Bloch-Redfield-Wangsness (BRW) relaxation theory, to investigate compass sensitivity. Previous research hypothesized that European robin's cryptochrome 4a (ErCry4a) optimized intra-protein motion to minimize spin relaxation, enhancing magnetic sensing compared to the plant Arabidopsis thaliana's cryptochrome 1 (AtCry1). Different correlation times of the nuclear hyperfine coupling constants in AtCry1 and ErCry4a were indeed found, leading to distinct radical pair recombination yields in the two species, with ErCry4a showing optimized sensitivity. However, this optimization is likely negligible in realistic spin systems with numerous nuclear spins. Beyond insights in magnetic sensing, the study presents a detailed method employing molecular dynamics simulations to assess for spin relaxation effects on chemical reactions with realistically modelled protein motion, relevant for studying radical pair reactions at finite temperature.

13.
J Med Internet Res ; 26: e49403, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39110493

RESUMO

BACKGROUND: The use of wearable monitoring devices (WMDs), such as smartwatches, is advancing support and care for community-dwelling older adults across the globe. Despite existing evidence of the importance of WMDs in preventing problems and promoting health, significant concerns remain about the decline in use after a period of time, which warrant an understanding of how older adults experience the devices. OBJECTIVE: This study aims to explore and describe the experiences of community-dwelling older adults after receiving our interventional program, which included the use of a smartwatch with support from a community health workers, nurses, and social workers, including the challenges that they experienced while using the device, the perceived benefits, and strategies to promote their sustained use of the device. METHODS: We used a qualitative descriptive approach in this study. Older adults who had taken part in an interventional study involving the use of smartwatches and who were receiving regular health and social support were invited to participate in focus group discussions at the end of the trial. Purposive sampling was used to recruit potential participants. Older adults who agreed to participate were assigned to focus groups based on their community. The focus group discussions were facilitated and moderated by 2 members of the research team. All discussions were recorded and transcribed verbatim. We used the constant comparison analytical approach to analyze the focus group data. RESULTS: A total of 22 participants assigned to 6 focus groups participated in the study. The experiences of community-dwelling older adults emerged as (1) challenges associated with the use of WMDs, (2) the perceived benefits of using the WMDs, and (3) strategies to promote the use of WMDs. In addition, the findings also demonstrate a hierarchical pattern of health-seeking behaviors by older adults: seeking assistance first from older adult volunteers, then from social workers, and finally from nurses. CONCLUSIONS: Ongoing use of the WMDs is potentially possible, but it is important to ensure the availability of technical support, maintain active professional follow-ups by nurses and social workers, and include older adult volunteers to support other older adults in such programs.


Assuntos
Agentes Comunitários de Saúde , Grupos Focais , Vida Independente , Pesquisa Qualitativa , Dispositivos Eletrônicos Vestíveis , Humanos , Idoso , Masculino , Feminino , Assistentes Sociais/psicologia , Enfermeiras e Enfermeiros/psicologia , Enfermeiras e Enfermeiros/estatística & dados numéricos , Idoso de 80 Anos ou mais , Pessoa de Meia-Idade
14.
Nano Lett ; 23(19): 9160-9169, 2023 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-37494286

RESUMO

Nanosubstrate engineering can be a biomechanical approach for modulating stem cell differentiation in tissue engineering. However, the study of the effect of clathrin-mediated processes on manipulating this behavior is unexplored. Herein, we develop integrin-binding nanosubstrates with confined nanogeometries that regulate clathrin-mediated adhesion- or endocytosis-active signaling pathways for modulating stem fates. Isotropically presenting ligands on the nanoscale enhances the expression of clathrin in cells, thereby facilitating uptake of dexamethasone-loaded nanoparticles (NPs) to boost osteogenesis of stem cells. In contrast, anisotropic ligand nanogeometry suppresses this clathrin-mediated NP entry by strengthening the association between clathrin and adhesion spots to reinforce mechanotransduced signaling, which can be abrogated by the pharmacological inhibition of clathrin. Meanwhile, inhibiting focal adhesion formation hinders cell spreading and enables a higher endocytosis efficiency. Our findings reveal the crucial roles of clathrin in both endocytosis and mechanotransduction of stem cells and provide the parameter of ligand nanogeometry for the rational design of biomaterials for tissue engineering.


Assuntos
Clatrina , Integrinas , Integrinas/metabolismo , Clatrina/metabolismo , Ligantes , Mecanotransdução Celular , Endocitose , Células-Tronco/metabolismo
15.
Int J Mol Sci ; 25(16)2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-39201574

RESUMO

RNA is a promising nucleic acid-based biomolecule for various treatments because of its high efficacy, low toxicity, and the tremendous availability of targeting sequences. Nevertheless, RNA shows instability and has a short half-life in physiological environments such as the bloodstream in the presence of RNAase. Therefore, developing reliable delivery strategies is important for targeting disease sites and maximizing the therapeutic effect of RNA drugs, particularly in the field of immunotherapy. In this mini-review, we highlight two major approaches: (1) delivery vehicles and (2) chemical modifications. Recent advances in delivery vehicles employ nanotechnologies such as lipid-based nanoparticles, viral vectors, and inorganic nanocarriers to precisely target specific cell types to facilitate RNA cellular entry. On the other hand, chemical modification utilizes the alteration of RNA structures via the addition of covalent bonds such as N-acetylgalactosamine or antibodies (antibody-oligonucleotide conjugates) to target specific receptors of cells. The pros and cons of these technologies are enlisted in this review. We aim to review nucleic acid drugs, their delivery systems, targeting strategies, and related chemical modifications. Finally, we express our perspective on the potential combination of RNA-based click chemistry with adoptive cell therapy (e.g., B cells or T cells) to address the issues of short duration and short half-life associated with antibody-oligonucleotide conjugate drugs.


Assuntos
Sistemas de Liberação de Medicamentos , Imunoterapia , RNA , Humanos , Imunoterapia/métodos , Sistemas de Liberação de Medicamentos/métodos , Animais , Nanopartículas/química , Ácidos Nucleicos/administração & dosagem , Ácidos Nucleicos/química
16.
BMC Nurs ; 23(1): 232, 2024 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-38584270

RESUMO

BACKGROUND: As the population ages, a plethora of digital and mobile health applications for assistance with independent living have emerged. Still unknown, however, is how older adults sustain the use of these applications. AIM: This study sought to explore the experiences of older adults following their participation in a programme that combined the use of an mHealth application with proactive telecare nursing support. METHODS: We employed a concurrent mixed-methods design for this study. The quantitative strand included a survey, whereas the qualitative strand included open-ended questions as part of the survey to understand the participants' experiences. Participants for this study were community-dwelling older adults who had taken part in an interventional study that sought to examine the effects of mHealth and nurse support. A convenience sampling approach was employed to recruit potential participants for this study. FINDINGS: Fifty-five older adults participated. The majority expressed positive attitudes and satisfaction with the app and the nurses' support. The app and nurses' support helped participants to understand their health status and obtain health information. Reasons to halt app usage included technical issues and limited social support. CONCLUSION: Mobile apps with professional follow-up support could potentially support older adults in the community, although emerging concerns need to be addressed to sustain long-term usage of these apps.

17.
Small ; 19(6): e2206762, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36593512

RESUMO

Surface-enhanced Raman scattering (SERS) imaging has emerged as a promising tool for guided cancer diagnosis and synergistic therapies, such as combined chemotherapy and photothermal therapy (chemo-PTT). Yet, existing therapeutic agents often suffer from low SERS sensitivity, insufficient photothermal conversion, or/and limited drug loading capacity. Herein, a multifunctional theragnostic nanoplatform consisting of mesoporous silica-coated gold nanostar with a cyclic Arg-Gly-Asp (RGD)-coated gold nanocluster shell (named RGD-pAS@AuNC) is reported that exhibits multiple "hot spots" for pronouncedly enhanced SERS signals and improved near-infrared (NIR)-induced photothermal conversion efficiency (85.5%), with a large capacity for high doxorubicin (DOX) loading efficiency (34.1%, named RGD/DOX-pAS@AuNC) and effective NIR-triggered DOX release. This nanoplatform shows excellent performance in xenograft tumor model of HeLa cell targeting, negligible cytotoxicity, and good stability both in vitro and in vivo. By SERS imaging, the optimal temporal distribution of injected RGD/DOX-pAS@AuNCs at the tumor site is identified for NIR-triggered local chemo-PTT toward the tumor, achieving ultraeffective therapy in tumor cells and tumor-bearing mouse model with 5 min of NIR irradiation (0.5 W cm-2 ). This work offers a promising approach to employing SERS imaging for effective noninvasive tumor treatment by on-site triggered chemo-PTT.


Assuntos
Nanopartículas , Neoplasias , Humanos , Animais , Camundongos , Células HeLa , Ouro/farmacologia , Terapia Fototérmica , Fototerapia/métodos , Doxorrubicina/farmacologia , Oligopeptídeos
18.
Gastrointest Endosc ; 98(5): 813-821.e3, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37307902

RESUMO

BACKGROUND AND AIMS: Blue-light imaging (BLI) is a new image-enhanced endoscopy with a wavelength filter similar to narrow-band imaging (NBI). We compared the 2 with white-light imaging (WLI) on proximal colonic lesion detection and miss rates. METHODS: In this 3-arm prospective randomized study with tandem examination of the proximal colon, we enrolled patients aged ≥40 years. Eligible patients were randomized in 1:1:1 ratio to receive BLI, NBI, or WLI during the first withdrawal from the proximal colon. The second withdrawal was performed using WLI in all patients. Primary outcomes were proximal polyp (pPDRs) and adenoma (pADRs) detection rates. Secondary outcomes were miss rates of proximal lesions found on tandem examination. RESULTS: Of 901 patients included (mean age, 64.7 years; 52.9% men), 48.1% underwent colonoscopy for screening or surveillance. The corresponding pPDRs of the BLI, NBI, and WLI groups were 45.8%, 41.6, and 36.6%, whereas the corresponding pADRs were 36.6%, 33.8%, and 28.3%. There was a significant difference in pPDR and pADR between BLI and WLI groups (difference, 9.2% [95% confidence interval {CI}, 3.3-16.9] and 8.3% [95% CI, 2.7-15.9]) and between NBI and WLI groups (difference, 5.0% [95% CI, 1.4-12.9] and 5.6% [95% CI, 2.1-13.3]). Proximal adenoma miss rates were significantly lower with BLI (19.4%) than with WLI (27.4%; difference, -8.0%; 95% CI, -15.8 to -.1) but not between NBI (27.2%) and WLI. CONCLUSIONS: Both BLI and NBI were superior to WLI on detecting proximal colonic lesions, but only BLI had lower proximal adenoma miss rates than WLI. (Clinical trial registration number: NCT03696992.).

19.
Phys Chem Chem Phys ; 25(2): 975-982, 2023 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-36519379

RESUMO

Magnetic field effects on the yields of radical pair reactions are often characterised by the "half-field" parameter, B1/2, which encodes useful information on spin relaxation, radical recombination kinetics and electron-electron couplings as well as electron-nuclear hyperfine interactions. Here we use a variety of spin dynamics simulation methods to estimate the hyperfine-only values of B1/2 for the flavin-tryptophan radical pair, [FAD˙- TrpH˙+], thought to be the detector in the magnetic compass sense of migratory songbirds. The main findings are: (a) in the absence of fast recombination and spin relaxation, [FAD˙- TrpH˙+] radical pairs in solution and in the putative magnetoreceptor protein, cryptochrome, have B1/2 ≈ 1.89 mT and 2.46 mT, respectively. (b) The widely used expression for B1/2 due to Weller et al. (Chem. Phys. Lett, 1983, 96, 24-27) is only applicable to small, short-lived (∼5 ns), rapidly tumbling radical pairs in solution, and is quantitatively unreliable in the context of magnetoreception. (c) In the absence of molecular tumbling, the low-field effect for [FAD˙- TrpH˙+] is predicted to be abolished by the anisotropic components of the hyperfine interactions. Armed with the 2.46 mT "base value" for cryptochrome, measurements of B1/2 can be used to understand the impact of spin relaxation on its performance as a magnetic compass sensor.


Assuntos
Criptocromos , Triptofano , Triptofano/metabolismo , Compostos Orgânicos , Campos Magnéticos , Flavinas
20.
J Med Genet ; 59(3): 220-229, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-33526602

RESUMO

BACKGROUND: Identifying patients with BRCA mutations is clinically important to inform on the potential response to treatment and for risk management of patients and their relatives. However, traditional referral routes may not meet clinical needs, and therefore, mainstreaming cancer genetics has been shown to be effective in some high-income and high health-literacy settings. To date, no study has reported on the feasibility of mainstreaming in low-income and middle-income settings, where the service considerations and health literacy could detrimentally affect the feasibility of mainstreaming. METHODS: The Mainstreaming Genetic Counselling for Ovarian Cancer Patients (MaGiC) study is a prospective, two-arm observational study comparing oncologist-led and genetics-led counselling. This study included 790 multiethnic patients with ovarian cancer from 23 sites in Malaysia. We compared the impact of different method of delivery of genetic counselling on the uptake of genetic testing and assessed the feasibility, knowledge and satisfaction of patients with ovarian cancer. RESULTS: Oncologists were satisfied with the mainstreaming experience, with 95% indicating a desire to incorporate testing into their clinical practice. The uptake of genetic testing was similar in the mainstreaming and genetics arm (80% and 79%, respectively). Patient satisfaction was high, whereas decision conflict and psychological impact were low in both arms of the study. Notably, decisional conflict, although lower than threshold, was higher for the mainstreaming group compared with the genetics arm. Overall, 13.5% of patients had a pathogenic variant in BRCA1 or BRCA2, and there was no difference between psychosocial measures for carriers in both arms. CONCLUSION: The MaGiC study demonstrates that mainstreaming cancer genetics is feasible in low-resource and middle-resource Asian setting and increased coverage for genetic testing.


Assuntos
Oncologistas , Neoplasias Ovarianas , Proteína BRCA1/genética , Proteína BRCA2/genética , Aconselhamento , Feminino , Aconselhamento Genético , Testes Genéticos/métodos , Humanos , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/epidemiologia , Neoplasias Ovarianas/genética , Estudos Prospectivos
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