Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.274
Filtrar
1.
ACS Cent Sci ; 10(8): 1594-1608, 2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-39220688

RESUMO

The combined inhibition of endoplasmic reticulum (ER) α-glucosidases I and II has been shown to inhibit replication of a broad range of viruses that rely on ER protein quality control. We found, by screening a panel of deoxynojirimycin and cyclitol glycomimetics, that the mechanism-based ER α-glucosidase II inhibitor, 1,6-epi-cyclophellitol cyclosulfate, potently blocks SARS-CoV-2 replication in lung epithelial cells, halting intracellular generation of mature spike protein, reducing production of infectious progeny, and leading to reduced syncytium formation. Through activity-based protein profiling, we confirmed ER α-glucosidase II inhibition in primary airway epithelial cells, grown at the air-liquid interface. 1,6-epi-Cyclophellitol cyclosulfate inhibits early pandemic and more recent SARS-CoV-2 variants, as well as SARS-CoV and MERS-CoV. The reported antiviral activity is comparable to the best-in-class described glucosidase inhibitors, all competitive inhibitors also targeting ER α-glucosidase I and other glycoprocessing enzymes not involved in ER protein quality control. We propose selective blocking ER-resident α-glucosidase II in a covalent and irreversible manner as a new strategy in the search for effective antiviral agents targeting SARS-CoV-2 and other viruses that rely on ER protein quality control.

2.
Arthroplasty ; 6(1): 44, 2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-39218949

RESUMO

BACKGROUND: Ligament tension balance is a major determinant for the success of total knee replacement (TKR). The present study aimed at determining the inter-rater and intra-rater reliability in performing ligament tension assessment using an imageless robotic-assisted TKR. METHODS: Twenty-four knees in 21 patients who received robotic-assisted TKR for end-stage varus osteoarthritis were examined. Three orthopedic specialists and six orthopedic trainees participated in the operations. Data from the ligament tension assessment were collected during the operations. RESULTS: For the inter-rater reliability, "extension medial" and "flexion medial" had excellent reliability whilst "extension lateral" and "flexion lateral" had good-to-excellent reliability. For the intra-rater reliability, "extension medial" showed excellent reliability, "extension lateral" and "flexion medial" showed good-to-excellent reliability, and "flexion lateral" showed moderate-to-excellent reliability. CONCLUSIONS: Robotic-assisted technology provides a reliable solution to improve ligament tension assessment. All ligament tension assessments with the use of the technology could demonstrate at least good-to-excellent reliability except for the intra-rater reliability of "flexion lateral".

3.
Vaccine ; 42(26): 126317, 2024 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-39276621

RESUMO

This study examined the strength and durability of antibody responses in 277 adults who received a heterologous third dose of the BNT162b2 vaccine, following two doses of an inactivated vaccine. Neutralizing antibody levels against both the ancestral virus and Omicron BA.2 subvariant decreased from one month to 6 months after the third dose, and were then maintained at 12 months. Participants who received both a fourth dose and reported a SARS-CoV-2 infection had the highest antibody titers at 365 days after the third dose. Individuals with chronic medical conditions had lower antibody levels against the Omicron BA.2 subvariant at 12 months after the third dose. The results suggest that the heterologous third dose provides durable neutralizing antibody responses, which may be influenced by subsequent infection or vaccination and pre-existing medical conditions. These findings may help explain the differences in immune protection between vaccination and natural infection.

4.
IJID Reg ; 12: 100421, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39281194

RESUMO

Objectives: The burden of SARS-CoV-2 infection in people living with HIV (PLHIV) in South Sudan is unknown. Methods: We conducted a cross-sectional seroprevalence survey of SARS-CoV-2 immunoglobulin (Ig) G antibodies and other diseases of public health importance (strongyloidiasis, toxoplasmosis) in PLHIV in South Sudan during April 1, 2020-April 30, 2022. We used a multiplex SARS-CoV-2 immunoassay to detect IgG antibodies targeting the SARS-CoV-2 spike, receptor binding domain, and nucelocapsid (N) proteins, and antigens for other pathogens (Strongyloides stercoralis and Toxoplasma gondii). Results: Among 3518 samples tested, seroprevalence of IgG antibodies to SARS-CoV-2 spike protein and receptor binding domain 591 and nucleocapsid ranged from 1.4% (95% confidence interval [CI]: 0.9-2.1%) in April-June 2020 to 53.3% (95% CI: 49.5-57.1%) in January-March 2022. The prevalence of S. stercoralis IgG ranged between 27.3% (95% CI: 23.4-31.5%) in October-December 2021 and 47.2% (95% CI: 37.8-56.8%) in July-September 2021, and, for T. gondii IgG, prevalence ranged from 15.5% (95% CI: 13.3-17.9%) in April-June 2020 to 36.2% (95% CI: 27.4-46.2%) July-September 2021. Conclusions: By early 2022, PLHIV in South Sudan had high rates of SARS-CoV-2 seropositivity. Surveillance of diseases of global health concern in PLHIV is crucial to estimate population-level exposure and inform public health responses.

5.
Nat Immunol ; 25(10): 1871-1883, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39289557

RESUMO

PD-1 is a key negative regulator of CD8+ T cell activation and is highly expressed by exhausted T cells in cancer and chronic viral infection. Although PD-1 blockade can improve viral and tumor control, physiological PD-1 expression prevents immunopathology and improves memory formation. The mechanisms driving high PD-1 expression in exhaustion are not well understood and could be critical to disentangling its beneficial and detrimental effects. Here, we functionally interrogated the epigenetic regulation of PD-1 using a mouse model with deletion of an exhaustion-specific PD-1 enhancer. Enhancer deletion exclusively alters PD-1 expression in CD8+ T cells in chronic infection, creating a 'sweet spot' of intermediate expression where T cell function is optimized compared to wild-type and Pdcd1-knockout cells. This permits improved control of chronic infection without additional immunopathology. Together, these results demonstrate that tuning PD-1 via epigenetic editing can reduce CD8+ T cell dysfunction while avoiding excess immunopathology.


Assuntos
Linfócitos T CD8-Positivos , Epigênese Genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptor de Morte Celular Programada 1 , Animais , Receptor de Morte Celular Programada 1/metabolismo , Receptor de Morte Celular Programada 1/genética , Linfócitos T CD8-Positivos/imunologia , Camundongos , Ativação Linfocitária/imunologia , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/virologia , Elementos Facilitadores Genéticos/genética
6.
BMC Infect Dis ; 24(1): 843, 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39164620

RESUMO

BACKGROUND: Rapid point-of-care tests for malaria are now widely used in many countries to guide the initial clinical management of patients presenting with febrile illness. With China having recently achieved malaria elimination, better understanding regarding the identity and distribution of major non-malarial causes of febrile illnesses is of particular importance to inform evidence-based empirical treatment policy. METHODS: A systematic review of published literature was undertaken to characterise the spectrum of pathogens causing non-malaria febrile illness in China (1980-2015). Literature searches were conducted in English and Chinese languages in six databases: Ovid MEDLINE, Global Health, EMBASE, Web of Science™ - Chinese Science Citation Database SM, The China National Knowledge Infrastructure (CNKI), and WanFang Med Online. Selection criteria included reporting on an infection or infections with a confirmed diagnosis, defined as pathogens detected in or cultured from samples from normally sterile sites, or serological evidence of current or past infection. The number of published articles, reporting a given pathogen were presented, rather than incidence or prevalence of infection. RESULTS: A total of 57,181 records from 13 provinces of China where malaria used to be endemic were screened, of which 392 met selection criteria and were included in this review. The review includes 60 (15.3%) records published from 1980 to 2000, 211 (53.8%) from 2001 to 2010 and 121 (30.9%) from 2011 to 2015;. Of the 392 records, 166 (42.3%) were from the eastern region of China, 120 (30.6%) were from the south-west, 102 (26.0%) from south-central, and four (1.0%) were multi-regional studies. Bacterial infections were reported in 154 (39.3%) records, viral infections in 219 (55.9%), parasitic infections in four (1.0%), fungal infections in one (0.3%), and 14 (3.6%) publications reported more than one pathogen group. Participants of all ages were included in 136 (34.7%) studies, only adults in 75 (19.1%), only children in 17 (4.3%), only neonates in two (0.5%) and the age distribution was not specified in 162 (41.3%) records. The most commonly reported bacterial pathogens included Typhoidal Salmonella (n = 30), Orientia/ Rickettsia tsutsugamushi (n = 31), Coxiella burnetii (n = 17), Leptospira spp. (n = 15) and Brucella spp. (n = 15). The most commonly reported viral pathogens included Hantavirus/Hantaan virus (n = 89), dengue virus (DENV) (n = 76 including those with unknown serovars), Japanese encephalitis virus (n = 21), and measles virus (n = 15). The relative lack of data in the western region of the country, as well as in in neonates and children, represented major gaps in the understanding of the aetiology of fever in China. CONCLUSIONS: This review presents a landscape of non-malaria pathogens causing febrile illness in China over 36 years as the country progressed toward malaria elimination. These findings can inform guidelines for clinical management of fever cases and infection surveillance and prevention, and highlight the need to standardize operational and reporting protocols for better understanding of fever aetiology in the country.


Assuntos
Febre , Humanos , China/epidemiologia , Febre/epidemiologia , Febre/etiologia , Malária/epidemiologia
7.
J Infect Dis ; 2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-39197019

RESUMO

BACKGROUND: Understanding factors affecting the infectiousness of influenza cases is crucial for disease prevention and control. Viral shedding is expected to correlate with infectiousness of cases, but it is strongly associated with age and the presence of symptoms. METHODS: To elucidate this complex interplay, we analyze with an individual-based household transmission model a detailed household transmission study of influenza with 442 households and 1710 individuals from 2008 to 2017 in Hong Kong, to characterize the household transmission dynamics and identify factors affecting transmissions. RESULTS: We estimate that age, fever symptoms and viral load were all associated with higher infectiousness. However, by model comparison, the best model includes age and fever as factors affecting individual infectiousness, and estimates that pre-school and school-age children were 317% (95% credible interval (CrI): 103%, 1042%) and 161% (95% CrI: 33%, 601%) more infectious than adults respectively, and patients having fever had 146% (95% CrI: 37%, 420%) higher infectiousness. Adding heterogeneity on individual infectiousness of cases does not improve the model fit, suggesting these factors could explain the difference in individual infectiousness. CONCLUSIONS: Our study clarifies the contribution of age, symptoms and viral shedding to individual infectiousness of influenza cases in households.

8.
Nat Commun ; 15(1): 7358, 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39191745

RESUMO

Whole virion inactivated vaccine CoronaVac (C) and Spike (S) mRNA BNT162b2 (B) vaccines differ greatly in their ability to elicit neutralizing antibodies but have somewhat comparable effectiveness in protecting from severe COVID-19. We conducted further analyses for a randomized trial (Cobovax study, NCT05057169) of third dose homologous and heterologous booster vaccination, i.e. four interventions CC-C, CC-B, BB-C and BB-B. Here, we assess vaccine immunogenicity beyond neutralizing function, including S and non-S antibodies with Fc receptor (FcR) binding, antibody avidity and T cell specificity to 6 months post-vaccination. Ancestral and Omicron S-specific IgG and FcR binding are significantly higher by BNT162b2 booster than CoronaVac, regardless of first doses. Nucleocapsid (N) antibodies are only increased in homologous boosted CoronaVac participants (CC-C). CoronaVac primed participants have lower baseline S-specific CD4+ IFNγ+ cells, but are significantly increased by either CoronaVac or BNT162b2 boosters. Priming vaccine content defined T cell peptide specificity preference, with S-specific T cells dominating B primed groups and non-S structural peptides contributing more in C primed groups, regardless of booster type. S-specific CD4+ T cell responses, N-specific antibodies, and antibody effector functions via Fc receptor binding may contribute to protection and compensate for less potent neutralizing responses in CoronaVac recipients.


Assuntos
Anticorpos Neutralizantes , Anticorpos Antivirais , Vacina BNT162 , Vacinas contra COVID-19 , COVID-19 , Receptores Fc , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Vacinas de Produtos Inativados , Vacinas de mRNA , Humanos , SARS-CoV-2/imunologia , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/administração & dosagem , COVID-19/prevenção & controle , COVID-19/imunologia , Receptores Fc/imunologia , Anticorpos Antivirais/imunologia , Anticorpos Neutralizantes/imunologia , Vacina BNT162/imunologia , Vacina BNT162/administração & dosagem , Vacinas de Produtos Inativados/imunologia , Vacinas de Produtos Inativados/administração & dosagem , Vacinas de mRNA/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Feminino , Imunização Secundária , Imunogenicidade da Vacina , Adulto , Linfócitos T/imunologia , Masculino , Imunoglobulina G/imunologia , Pessoa de Meia-Idade
9.
J Chem Phys ; 161(6)2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39132786

RESUMO

Vibrational sum frequency generation can provide valuable structural information at surfaces and buried interfaces. Relating the measured spectra to the complex-valued second-order susceptibility χ(2) is at the heart of the technique and a requisite step in nearly all subsequent analyses. The magnitude and phase of χ(2) as a function of frequency reveal important information about molecules and materials in regions where centrosymmetry is broken. In this tutorial-style perspective, the origins of the χ(2) phase are first described, followed by the utility of phase determination. Finally, some practical methods of phase extraction are discussed.

10.
Eur Radiol ; 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39030373

RESUMO

OBJECTIVES: Apply a modified Delphi-based approach and produce a practical, radiology-specific set of definitions for interpretation and standardization of the multiple MRI findings in axial spondyloarthritis (ax-SpA), specifically to aid the general radiologist with a musculoskeletal interest, working with gold standard basic MRI protocols. MATERIALS AND METHODS: We report the results of a modified Delphi-based consensus of 35 experts from 13 countries in the Arthritis Subcommittee of the European Society of Musculoskeletal Radiology (ESSR). Seventeen definitions were created (i.e., nine for the spine and eight for the sacroiliac joint) and two Delphi rounds were conducted on an electronic database, collated and revised by the project leader with agreement. Group leads were appointed for each definition following the first round. Final definitions included only those that reached a consensus > 80%; if > 50% agreed on exclusion consensus, definitions were excluded. Final results have been shared during the Arthritis meeting at the Annual ESSR Congress. RESULTS: Fourteen definitions, eight for the spine and six for the sacroiliac joint were agreed for standardized reporting. Andersson's, anterior corner sclerotic and costovertebral joint inflammatory lesions of the spine, with active and non-active erosions, and fat metaplasia of the sacroiliac joint reaching the highest consensus (≥ 95%). More than 50% of the experts agreed to exclude joint space inflammation in the sacroiliac joint and tissue backfill. Syndesmophytes reached 76% agreement. CONCLUSIONS: Agreed definitions by expert radiologists using a modified Delphi process, should allow standardized actionable radiology reports and clarity in reporting terminology of ax-SpA. CLINICAL RELEVANCE STATEMENT: The proposed definitions will support reporting from musculoskeletal and general radiologists working with gold-standard basic MRI, improve confidence in lesion assessment, and standardize terminology to provide actionable reports on MRI in patients with ax-SpA. KEY POINTS: Experts applied a modified Delphi method to optimize the definitions of MRI findings of ax-SpA. After two Delphi rounds and one in-person meeting, fourteen definitions reached the agreement threshold. These consensus-based definitions will aid in actionable reporting specifically for the general radiologist with a musculoskeletal interest.

11.
Clin Infect Dis ; 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39041887

RESUMO

BACKGROUND: Studies have reported that repeated annual vaccination may influence influenza vaccination effectiveness in the current season. METHODS: We established a 5-year randomized placebo-controlled trial of repeated influenza vaccination (Flublok, Sanofi Pasteur) in adults 18-45 years of age. In the first two years, participants received vaccination (V) or saline placebo (P) as follows: P-P, P-V, or V-V. Serum samples were collected each year just before vaccination and after 30 and 182 days. A subset of sera collected at 5 timepoints from 95 participants were tested for antibodies against vaccine strains. RESULTS: From 23 October 2020 through 11 March 2021 we enrolled and randomized 447 adults. Among vaccinated individuals, antibody titers increased between days 0 and 30 against each of the vaccine strains, with smaller increases for repeat vaccinees who on average had higher pre-vaccination titers in year 2. There were statistically significant differences in the proportion of participants achieving >=four-fold rises in antibody titer for the repeat vaccinees for influenza A(H1N1), B/Victoria and B/Yamagata, but not for A(H3N2). Among participants who received vaccination in year 2, there were no statistically significant differences between the P-V and V-V groups in geometric mean titers at day 30 or the proportions of participants with antibody titers ≥40 at day 30 for any of the vaccine strains. CONCLUSIONS: In the first two years, during which influenza did not circulate, repeat vaccinees and first-time vaccinees had similar post-vaccination geometric mean titers to all four vaccine strains, indicative of similar levels of clinical protection.

12.
Evol Appl ; 17(7): e13735, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39006004

RESUMO

For almost 200 years, the taxonomy of cutthroat trout (Oncorhynchus clarkii), a salmonid native to Western North America, has been in flux as ichthyologists and fisheries biologists have tried to describe the diversity within these fishes. Starting in the 1950s, Robert Behnke reexamined the cutthroat trout and identified 14 subspecies based on morphological traits, Pleistocene events, and modern geographic ranges. His designations became instrumental in recognizing and preserving the remaining diversity of cutthroat trout. Over time, molecular techniques (i.e. karyotypes, allozymes, mitochondrial DNA, SNPs, and microsatellite arrays) have largely reinforced Behnke's phylogenies, but have also revealed that some relationships are consistently weakly supported. To further resolve these relationships, we generated de novo transcriptomes for nine cutthroat subspecies, as well as a Bear River Bonneville form and two Colorado River lineages (blue and green). We present phylogenies of these subspecies generated from multiple sets of orthologous genes extracted from our transcriptomes. We confirm many of the relationships identified in previous morphological and molecular studies, as well as discuss the importance of significant differences apparent in our phylogenies from these studies within a geological perspective. Specific findings include three distinct clades: (1) Bear River Bonneville form and Yellowstone cutthroat trout; (2) Bonneville cutthroat trout (n = 2); and (3) Greenback and Rio Grande cutthroat trout. We also identify potential gene transfer between Bonneville cutthroat trout and a population of Colorado River green lineage cutthroat trout. Using these findings, it appears that additional groups warrant species-level consideration if other recent species elevations are retained.

13.
J Clin Med ; 13(13)2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38999312

RESUMO

Background: The electrodes of implantable cardiac devices (ICDs) may cause significant problems in cardiac computed tomography (CT) because they are a source of artifacts that obscure surrounding structures and possible pathology. There are a few million patients currently with ICDs, and some of these patients will require cardiac imaging due to coronary artery disease or problems with ICDs. Modern CT scanners can reduce some of the metal artifacts because of MAR software, but in some vendors, it does not work with ECG gating. Introduced in 2008, dual-energy CT scanners can generate virtual monoenergetic images (VMIs), which are much less susceptible to metal artifacts than standard CT images. Objective: This study aimed to evaluate if dual-energy CT can reduce metal artifacts caused by ICD leads by using VMIs. The second objective was to determine how the angle between the electrode and the plane of imaging affects the severity of the artifacts in three planes of imaging. Methods: A 3D-printed model was constructed to obtain a 0-90-degree field at 5-degree intervals between the electrode and each of the planes: axial, coronal, and sagittal. This electrode was scanned in dual-energy and single-energy protocols. VMIs with an energy of 40-140 keV with 10 keV intervals were reconstructed. The length of the two most extended artifacts originating from the tip of the electrode and 2 cm above it-at the point where the thick metallic defibrillating portion of the electrode begins-was measured. Results: For the sagittal plane, these observations were similar for both points of the ICDs that were used as the reference location. VMIs with an energy over 80 keV produce images with fewer artifacts than similar images obtained in the single-energy scanning mode. Conclusions: Virtual monoenergetic imaging techniques may reduce streak artifacts arising from ICD electrodes and improve the quality of the image. Increasing the angle of the electrode as well as the imaging plane can reduce artifacts. The angle between the electrode and the beam of X-rays can be increased by tilting the gantry of the scanner or lifting the upper body of the patient.

15.
Anal Chem ; 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39016148

RESUMO

The detection of trace adulterants in opioid samples is an important aspect of drug checking, a harm reduction measure that is required as a result of the variability and unpredictability of the illicit drug supply. While many analytical methods are suitable for such analysis, community-based approaches require techniques that are amenable to point-of-care applications with minimal sample preparation and automated analysis. We demonstrate that surface-enhanced Raman spectroscopy (SERS), combined with a random forest classifier, is able to detect the presence of two common sedatives, bromazolam (0.32-36% w/w) and xylazine (0.15-15% w/w), found in street opioid samples collected as a part of a community drug checking service. The Raman predictions, benchmarked against mass spectrometry results, exhibited high specificity (88% for bromazolam, 96% for xylazine) and sensitivity (88% for bromazolam, 92% for xylazine) for the compounds of interest. We additionally provide evidence that this exceeds the performance of a more conventional approach using infrared spectral data acquired on the same samples. This demonstrates the feasibility of SERS for point-of-care analysis of challenging multicomponent samples containing trace adulterants.

16.
Adv Mater ; : e2407425, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38899741

RESUMO

The infiltration and cytotoxicity of chimeric antigen receptor (CAR)-T cells are crucial for effective elimination of solid tumors. While metallo-immunotherapy is a promising strategy that can activate the antitumor immunity, its role in promoting CAR-T cell therapy remains elusive. The first single-element nanomaterial based on chromium nanoparticles (Cr NPs) for cancer photo-metallo-immunotherapy has been reported previously. Herein, an extended study using biodegradable polydopamine as a versatile carrier for these nanoparticles, enabling synergistic CAR-T cell therapy, is reported. The results show that these nanocomposites with or without further encapsulation of the anticancer drug alpelisib can promote the CAR-T cell migration and antitumor effect. Upon irradiation with near-infrared light, they caused mild hyperthermia that can "warm" the "cold" tumor microenvironment (TME). The administration of B7-H3 CAR-T cells to NOD severe combined immunodeficiency gamma mice bearing a human hepatoma or PIK3CA-mutated breast tumor can significantly inhibit the tumor growth after the induction of tumor hyperthermia by the nanocomposites and promote the secretion of serum cytokines, including IL-2, IFN-γ, and TNF-α. The trivalent Cr3+ ions, which are the major degradation product of these nanocomposites, can increase the CXCL13 and CCL3 chemokine expressions to generate tertiary lymphoid structures (TLSs) in the tumor tissues, facilitating the CAR-T cell infiltration.

19.
Adv Sci (Weinh) ; 11(31): e2401012, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38884205

RESUMO

Senescence is a cellular response having physiological and reparative functions to preserve tissue homeostasis and suppress tumor growth. However, the accumulation of senescent cells would cause deleterious effects that lead to age-related dysfunctions and cancer progression. Hence, selective detection and elimination of senescent cells are crucial yet remain a challenge. A ß-galactosidase (ß-gal)-activated boron dipyrromethene (BODIPY)-based photosensitizer (compound 1) is reported here that can selectively detect and eradicate senescent cells. It contains a galactose moiety connected to a pyridinium BODIPY via a self-immolative nitrophenylene linker, of which the photoactivity is effectively quenched. Upon interactions with the senescence-associated ß-gal, it undergoes enzymatic hydrolysis followed by self-immolation, leading to the release of an activated BODIPY moiety by which the fluorescence emission and singlet oxygen generation are restored. The ability of 1 to detect and eliminate senescent cells is demonstrated in vitro and in vivo, using SK-Mel-103 tumor-bearing mice treated with senescence-inducing therapy. The results demonstrate that 1 can be selectively activated in senescent cells to trigger a robust senolytic effect upon irradiation. This study breaks new ground in the design and application of new senolytic agents based on photodynamic therapy.


Assuntos
Senescência Celular , Fotoquimioterapia , Fármacos Fotossensibilizantes , Porfobilinogênio , beta-Galactosidase , beta-Galactosidase/metabolismo , Senescência Celular/efeitos dos fármacos , Fármacos Fotossensibilizantes/farmacologia , Animais , Camundongos , Fotoquimioterapia/métodos , Humanos , Porfobilinogênio/análogos & derivados , Porfobilinogênio/farmacologia , Porfobilinogênio/química , Compostos de Boro/farmacologia , Compostos de Boro/química , Modelos Animais de Doenças , Linhagem Celular Tumoral
20.
Analyst ; 149(12): 3288-3292, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38808583

RESUMO

An acetal-linked dimeric phthalocyanine has been synthesised and immobilised on the surface of gold nanobipyramids. The resulting nanocomposite serves as a highly sensitive probe for intracellular pH through its acid-responsive fluorescence and surface-enhanced Raman scattering signals. The phthalocyanine units released in the acidic intracellular environment can also effectively eliminate the cancer cells upon light irradiation, rendering this simple fabricated nanosystem a bimodal and bifunctional theranostic agent.


Assuntos
Ouro , Indóis , Isoindóis , Fotoquimioterapia , Indóis/química , Indóis/efeitos da radiação , Ouro/química , Humanos , Concentração de Íons de Hidrogênio , Fotoquimioterapia/métodos , Nanopartículas Metálicas/química , Nanopartículas Metálicas/efeitos da radiação , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/efeitos da radiação , Análise Espectral Raman/métodos , Neoplasias , Dimerização , Linhagem Celular Tumoral
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA