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1.
Br J Ophthalmol ; 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38729765

RESUMO

BACKGROUND/AIMS: To evaluate the diagnostic accuracy of spectral-domain optical coherence tomography (SD OCT) combined with OCT angiography (OCTA) for myopic myopic macular neovascularisation (MNV) activity. METHODS: Both eyes of patients with myopic MNV diagnosed with fluorescein angiography (FA), SD OCT and OCTA were assessed by unmasked investigators. The images were deidentified and randomised before graded by masked investigators, who determined the presence of active myopic MNV by using SD OCT together with OCTA without FA and by FA alone, respectively. The findings of masked investigators were compared with unmasked investigators. RESULTS: 213 eyes of 110 patients comprising 499 imaging episodes were eligible for grading. For diagnosing new-onset myopic MNV without FA, combined use of SD OCT and OCTA had a sensitivity of 0.94, specificity of 0.84 and area under the curve (AUC) of 0.92. FA had a sensitivity of 0.52 (p<0.01), specificity of 0.80 (p=0.38) and AUC of 0.66 (p<0.01). For recurrent myopic MNV, the combination of SD OCT and OCTA had a sensitivity of 0.98, specificity of 0.78 and AUC of 0.88. FA had a sensitivity of 0.50 (p=0.04), specificity of 0.76 (p=0.85) and AUC of 0.63 (p=0.01). Myopic traction maculopathy was more frequently associated with recurrent myopic MNV (p<0.01). CONCLUSION: SD OCT with dense volumetric scan was highly sensitive for diagnosing myopic MNV. The addition of OCTA improved the diagnostic specificity without FA. Monitoring of the longitudinal changes on SD OCT and judicious use of FA is a reliable surveillance strategy for myopic MNV.

2.
Environ Sci Technol ; 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38768015

RESUMO

Tropical small island developing states (SIDS), with their geographical isolation and limited resources, heavily rely on the fisheries industry for food and revenue. The presence of marine lipophilic phycotoxins (MLPs) poses risks to their economy and human health. To understand the contamination status and potential risks, the Republic of Kiribati was selected as the representative tropical SIDS and 55 species of 256 coral reef fish encompassing multiple trophic levels and feeding strategies were collected to analyze 17 typical MLPs. Our results showed that the potential risks of ciguatoxins were the highest and approximately 62% of fish species may pose risks for consumers. Biomagnification of ciguatoxins was observed in the food web with a trophic magnification factor of 2.90. Brevetoxin-3, okadaic acid, and dinophysistoxin-1 and -2 were first reported, but the risks posed by okadaic acid and dinophysistoxins were found to be negligible. The correlation analysis revealed that fish body size and trophic position are unreliable metrics to indicate the associated risks and prevent the consumption of contaminated fish. The potential risks of MLPs in Kiribati are of concern, and our findings can serve as valuable inputs for developing food safety policies and fisheries management strategies specific to tropical SIDS contexts.

3.
J Fluoresc ; 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38294633

RESUMO

Apoptosis is the programmed cell death pathway that is critical for maintaining homeostasis, in which cancer cells can evade to ensure survival. For pharmaceutical drug discovery, it is important to characterize and compare different cancer therapeutics (i.e., small molecules, antibody drugs, cell therapies) that can initiate the process of apoptosis, enabling the identification of potential therapeutic candidates. In this work, we developed and demonstrated a multiplex detection method for monitoring apoptosis and necrosis with Annexin V, Caspase-3, and Propidium Iodide (PI) using the Cellaca® PLX Image Cytometer (Revvity Health Sciences, Inc., Lawrence, MA). First, apoptosis was induced in Jurkat and K562 cell lines with staurosporine over the course of 24 h, where apoptosis and necrosis were assessed at 0, 1, 1.5, 2, 4, 20, and 24 h timepoints. Samples were stained with Hoechst 33342 (total dye), Annexin V-APC (early-stage apoptosis), Caspase-3 488 (late-stage apoptosis), and PI (necrosis) at each timepoint and evaluated using image cytometry. Results showed that apoptotic factors and cascades were successfully detected along the pathway from early- to late-stage apoptosis, and ultimately necrosis. A clear trend was observed analyzing apoptotic and necrotic populations during the first 1.5 h, showing differences of up to ~15% in single Annexin V+ and Caspase-3+ populations in treated Jurkat cells, however, a significant increase in double positive apoptotic/necrotic cells for Annexin V+PI+ and Capase-3+PI+ was not observed until 20 h. Upon further analysis between apoptotic populations only, Annexin V+ only populations were higher than Caspase-3+ only populations by up to ~20% between 0 and 1.5 h. Conversely, K562 cells did not exhibit a notable change in apoptotic and necrotic populations due to low sensitivity to staurosporine. The proposed image cytometric detection method may provide an effective and efficient tool for rapid and reliable simultaneous detection of early- late-stage apoptosis, and necrosis. Therefore, allowing researchers to better characterize and screen potential cancer therapeutic drug candidates for their treatment efficacy in a higher throughput manner.

4.
J Fluoresc ; 34(2): 561-570, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37310590

RESUMO

The COVID-19 pandemic has created a worldwide public health crisis that has since resulted in 6.8 million reported deaths. The pandemic prompted the immediate response of researchers around the world to engage in rapid vaccine development, surveillance programs, and antiviral testing, which resulted in the delivery of multiple vaccines and repurposed antiviral drug candidates. However, the emergence of new highly transmissible SARS-CoV-2 variants has renewed the desire for discovering new antiviral drug candidates with high efficacy against the emerging variants of concern. Traditional antiviral testing methods employ the plaque-reduction neutralization tests (PRNTs), plaque assays, or RT-PCR analysis, but each assay can be tedious and time-consuming, requiring 2-3 days to complete the initial antiviral assay in biologically relevant cells, and then 3-4 days to visualize and count plaques in Vero cells, or to complete cell extractions and PCR analysis. In recent years, plate-based image cytometers have demonstrated high-throughput vaccine screening methods, which can be adopted for screening potential antiviral drug candidates. In this work, we developed a high-throughput antiviral testing method employing the Celigo Image Cytometer to investigate the efficacy of antiviral drug candidates on SARS-CoV-2 infectivity using a fluorescent reporter virus and their safety by measuring the cytotoxicity effects on the healthy host cell line using fluorescent viability stains. Compared to traditional methods, the assays defined here eliminated on average 3-4 days from our standard processing time for antiviral testing. Moreover, we were able to utilize human cell lines directly that are not typically amenable to PRNT or plaque assays. The Celigo Image Cytometer can provide an efficient and robust method to rapidly identify potential antiviral drugs to effectively combat the rapidly spreading SARS-CoV-2 virus and its variants during the pandemic.


Assuntos
COVID-19 , SARS-CoV-2 , Animais , Chlorocebus aethiops , Humanos , Células Vero , Pandemias , Ensaios de Triagem em Larga Escala/métodos , Antivirais/farmacologia
5.
J Immunol Methods ; 524: 113587, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38040192

RESUMO

Immunophenotyping has been the primary assay for characterization of immune cells from patients undergoing therapeutic treatments in clinical research, which is critical for understanding disease progression and treatment efficacy. Currently, flow cytometry has been the dominant methodology for characterizing surface marker expression for immunological research. Flow cytometry has been proven to be an effective and efficient method for immunophenotyping, however, it requires highly trained users and a large time commitment. Recently, a novel image cytometry system (Cellaca® PLX Image Cytometer, Revvity Health Sciences, Inc., Lawrence, MA) has been developed as a complementary method to flow cytometry for performing rapid and high-throughput immunophenotyping. In this work, we demonstrated an image cytometric screening method to characterize immune cell populations, streamlining the analysis of routine surface marker panels. The T cell, B cell, NK cell, and monocyte populations of 46 primary PBMC samples from subjects enrolled in autoimmune and oncological disease study cohorts were analyzed with two optimized immunophenotyping staining kits: Panel 1 (CD3, CD56, CD14) and Panel 2 (CD3, CD56, CD19). We validated the proposed image cytometry method by comparing the Cellaca® PLX and the AuroraTM flow cytometer (Cytek Biosciences, Fremont, CA). The image cytometry system was employed to generate bright field and fluorescent images, as well as scatter plots for multiple patient PBMC samples. In addition, the image cytometry method can directly determine cell concentrations for downstream assays. The results demonstrated comparable CD3, CD14, CD19, and CD56 cell populations from the primary PBMC samples, which showed an average of 5% differences between flow and image cytometry. The proposed image cytometry method provides a novel research tool to potentially streamline immunophenotyping workflow for characterizing patient samples in clinical studies.


Assuntos
Leucócitos Mononucleares , Linfócitos T , Humanos , Imunofenotipagem , Células Matadoras Naturais , Citometria de Fluxo/métodos , Antígenos CD19 , Citometria por Imagem
6.
Anal Biochem ; 685: 115389, 2024 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-37951455

RESUMO

Cell and gene therapy is a fast-growing field for cancer therapeutics requiring reliable instrumentation and technologies. Key parameters essential for satisfying Chemistry Manufacturing and Controls criteria standards are routinely performed using flow cytometry. Recently, image cytometry was developed for cell characterization and cell-based assays but had not yet demonstrated sufficient sensitivity for surface marker detection. We developed the Cellaca® PLX image cytometry system and the respective methodologies required for immunophenotyping, GFP and RFP transfection/transduction efficiencies, and cell health analyses for routine cell characterization. All samples tested were compared directly to results from the CytoFLEX flow cytometer. PBMCs were stained with T-cell surface markers for immunophenotyping, and results show highly comparable CD3, CD4, and CD8 populations (within 5 %). GFP- or RFP-expressing cell lines were analyzed for transfection/transduction efficiencies, and the percentage positive cells and respective viabilities were equivalent on both systems. Staurosporine-treated Jurkat cells were stained for apoptotic markers, where annexin V and caspase-3 positive cells were within 5 % comparing both instruments. The proposed system may provide a complementary tool for performing routine cell-based experiments with improved efficiency and sensitivity compared to prior image cytometers, which may be significantly valuable to the cell and gene therapy field.


Assuntos
Apoptose , Humanos , Imunofenotipagem , Transfecção , Linhagem Celular , Células Jurkat , Citometria de Fluxo/métodos
7.
Front Microbiol ; 14: 1236925, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37928680

RESUMO

Most signaling molecules are involved in inter-or intra-species communication, and signaling involving cross-kingdom cell-to-cell communication is limited. Howerver, algae and bacteria exchange nutrients and information in a range of interactions in marine environments. Multiple signaling molecules exist between algae and bacteria, including quorum-sensing molecules, nitric oxide, and volatile organic compounds. Recently, indole-3-acetic acid (IAA), an auxin hormone that is a well-studied signaling molecule in terrestrial ecosystems, was found to act as a cue in cross-kingdom communication between algae and bacteria in aquatic environments. To increase understanding of the roles of IAA in the phycosphere, the latest evidence regarding the ecological functions of IAA in cross-kingdom communication between algae and bacteria has been compiled in this review. The pathways of IAA biosynthesis, effects of IAA on algal growth & reproduction, and potential mechanisms at phenotypic and molecular levels are summarized. It is proposed that IAA is an important molecule regulating algal-bacterial interactions and acts as an invisible driving force in the formation of algal blooms.

8.
Toxins (Basel) ; 15(11)2023 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-37999520

RESUMO

Microbial interactions including competition, mutualism, commensalism, parasitism, and predation, which can be triggered by nutrient acquisition and chemical communication, are universal phenomena in the marine ecosystem. The interactions may influence the microbial population density, metabolism, and even their environmental functions. Herein, we investigated the interaction between a heterotrophic bicosoecid flagellate, Pseudobodo sp. (Bicoecea), and a dinoflagellate, Gambierdiscus balechii (Dinophyceae), which is a well-known ciguatera food poisoning (CFP) culprit. The presence of Pseudobodo sp. inhibited the algal proliferation and decreased the cardiotoxicity of zebrafish in the algal extract exposure experiment. Moreover, a significant difference in microbiome abundance was observed in algal cultures with and without Pseudobodo sp. Chemical analysis targeting toxins was performed by using liquid chromatography-tandem mass spectrometry (LC-MS/MS) combined with molecular networking (MN), showing a significant alteration in the cellular production of gambierone analogs and some super-carbon chain compounds. Taken together, our results demonstrated the impact of heterotrophic flagellate on the photosynthetic dinoflagellates, revealing the complex dynamics of algal toxin production and the ecological relationships related to dinoflagellates in the marine environment.


Assuntos
Ciguatera , Ciguatoxinas , Dinoflagellida , Animais , Dinoflagellida/metabolismo , Cromatografia Líquida , Ecossistema , Peixe-Zebra , Espectrometria de Massas em Tandem , Cromatografia Gasosa-Espectrometria de Massas , Ciguatoxinas/toxicidade
9.
J Fluoresc ; 2023 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-37736833

RESUMO

Cellular therapy development and manufacturing has focused on providing novel therapeutic cell-based products for various diseases. The International Organization for Standardization (ISO) has provided guidance on critical quality attributes (CQAs) that shall be considered when testing and releasing cellular therapeutic products. Cell count and viability measurements are two of the CQAs that are determined during development, manufacturing, testing, and product release. The ISO Cell Counting Standard Part 1 and 2 addressed the needs for improving the quality of cell counting results. However, there is currently no guidance on the qualification and selection of a fit-for-purpose cell viability detection method. In this work, we present strategies for the characterization and comparison of AO/PI and AO/DAPI staining methods using the heat-killed (HK) and low temperature/nutrient-deprived (LT/ND) cell death models to evaluate the comparability of cell viability measurements and identify potential causes of differences. We compared the AO/PI and AO/DAPI staining methods using HK and LT/ND-generated dead cells, investigated the staining time effects on cell viability measurements, and determined their viability linearity with different mixtures of live and dead cells. Furthermore, we validated AO/PI and AO/DAPI cell viability measurement with a long-term cell proliferation assay. Finally, we demonstrate a practical example of cell viability measurement comparison using AO/PI and AO/DAPI on antibiotic-selected transduced Jurkat and THP-1 cells to select a fit-for-purpose method for functional genomics screening. The proposed strategies may potentially enable scientists to properly characterize, compare, and select cell viability detection methods that are critical for cellular therapeutic product development and manufacturing.

10.
J Immunol Methods ; 521: 113538, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37597726

RESUMO

In cellular therapies chimeric antigen receptor (CAR) T or NK cells undergo phenotypic analysis at multiple stages during discovery and development of novel therapies. Patient samples are routinely analyzed via flow cytometry for population identification and distribution of CD3, CD4, and CD8 positive T cells. As an alternative or orthogonal method, image cytometry systems have been used to perform simple cell-based assays in lieu of flow cytometry. Recently, a new image cytometry system, the Cellaca® PLX (Revvity Health Sciences, Inc., Lawrence, MA), was developed for high-throughput cell counting and viability, immunophenotyping, transfection/transduction efficiency, and cell health assays. This novel instrument allows investigators to quickly assess several critical quality attributes (CQAs) such as cell identity, viability, and other relevant biological functions recommended by the International Organization for Standardization using the ISO Cell Characterization documents focused on cellular therapeutic products. In this work, we demonstrate a rapid and high-throughput image cytometry detection method for cellular immunophenotyping and viability using the Cellaca PLX system for samples throughout the cellular therapy workflow. Freshly isolated peripheral blood mononuclear cells (PBMCs) underwent red blood cell (RBC) lysis and CD3 enrichment. Samples were then subsequently stained with Hoechst/CD3/CD4/CD8 or Hoechst/CD3/CD8/RubyDead Dye surface marker kits and measured on the Cellaca PLX and three different flow cytometers for side-by-side comparison and assay validation. Acquisition and analysis of cell viability and cell populations was shown to be faster and more efficient process compared to flow while achieving highly comparable results between the two technology platforms. This data shows that the Cellaca PLX Image Cytometer may provide a rapid alternative or orthogonal method for PBMC immunophenotyping experiments, as well as potentially streamline the workflow to quickly move precious patient samples downstream within the development processes.


Assuntos
Linfócitos T CD8-Positivos , Leucócitos Mononucleares , Humanos , Imunofenotipagem , Células Matadoras Naturais , Bioensaio
12.
Mar Environ Res ; 189: 106044, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37321888

RESUMO

From July to August 2022, scleractinian coral communities in China's Greater Bay Area (GBA) in the northern South China Sea (nSCS) experienced an unprecedented bleaching event, despite the fact that coral communities in this area are often considered coral thermal refugia due to their high latitude distribution. Field surveys of six sites covering three main coral distribution areas of the GBA revealed that coral bleaching occurred at all sites. Bleaching was more severe in shallow water (1-3 m) than in deep water (4-6 m), as indicated by both percent bleached cover (51.80 ± 10.04% vs. 7.09 ± 7.37%) and bleached colonies (45.86 ± 11.22% vs. 6.58 ± 6.53%). Coral genera Acropora, Favites, Montipora, Platygyra, Pocillopora, and Porites showed high susceptibility to bleaching, and Acropora and Pocillopora suffered high post-bleaching mortality. In the three areas surveyed, analysis of oceanographic data detected marine heatwaves (MHWs) during the summer, with mean intensities between 1.62 and 1.97 °C and durations between 5 and 22 days. These MHWs were primarily driven by increased shortwave radiation due to strong western Pacific Subtropical High (WPSH), combined with reduced mixing between the surface and deep upwelling waters due to reduced wind speed. Comparing with histological oceanographic data showed that the 2022 MHWs were unprecedented, and there was a significant increase in the frequency, intensity, and total days of MHWs during 1982-2022. Furthermore, the heterogeneous distribution of summer MHW characteristics indicates that the coastal upwelling may modulate the spatial distribution of summer MHWs in nSCS through its cooling effect. Overall, our study indicates that MHWs may have affected the structure of the subtropical coral communities in the nSCS, and impaired their potential as thermal refugia.


Assuntos
Antozoários , Recifes de Corais , Animais , Branqueamento de Corais , China , Água
13.
J Ind Microbiol Biotechnol ; 50(1)2023 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-36948609

RESUMO

Mixed microorganism cultures are prevalent in the food industry. A variety of microbiological mixtures have been used in these unique fermenting processes to create distinctive flavor profiles and potential health benefits. Mixed cultures are typically not well characterized, which may be due to the lack of simple measurement tools. Image-based cytometry systems have been employed to automatically count bacteria or yeast cells. In this work, we aim to develop a novel image cytometry method to distinguish and enumerate mixed cultures of yeast and bacteria in beer products. Cellometer X2 from Nexcelom was used to count of Lactobacillus plantarum and Saccharomyces cerevisiae in mixed cultures using fluorescent dyes and size exclusion image analysis algorithm. Three experiments were performed for validation. (1) Yeast and bacteria monoculture titration, (2) mixed culture with various ratios, and (3) monitoring a Berliner Weisse mixed culture fermentation. All experiments were validated by comparing to manual counting of yeast and bacteria colony formation. They were highly comparable with ANOVA analysis showing p-value > 0.05. Overall, the novel image cytometry method was able to distinguish and count mixed cultures consistently and accurately, which may provide better characterization of mixed culture brewing applications and produce higher quality products.


Assuntos
Lactobacillus , Saccharomyces , Saccharomyces cerevisiae , Fermentação , Bactérias , Pão/microbiologia , Microbiologia de Alimentos
14.
SLAS Discov ; 28(3): 65-72, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36758833

RESUMO

Solid tumors account for approximately 90% of all adult human cancers. As such, the development of novel cellular therapies has become of increasing importance to target solid tumor malignancies, such as prostate, lung, breast, bladder, colon, and liver cancers. One such cellular therapy relies on the use of chimeric antigen receptor T cells (CAR-T cells). CAR-T cells are engineered to target specific antigens on tumor cells. To date, there are six FDA-approved CAR-T cell therapies that have been utilized for hematologic B cell malignancies. Immune cell trafficking and immunosuppressive factors within the tumor microenvironment increase the relative difficulty in developing a robust CAR-T cell therapy against solid tumors. Therefore, it is critical to develop novel methodologies for high-throughput phenotypic and functional assays using 3D tumor spheroid models to assess CAR-T cell products against solid tumors. In this manuscript, we discuss the use of CAR-T cells targeted towards PSMA, an antigen that is found on prostate cancer tumor cells, the second most common cause of cancer deaths among men worldwide. We demonstrate the use of high-throughput, plate-based image cytometry to characterize CAR-T cell-mediated cytotoxic potency against 3D prostate tumor spheroids. We were able to kinetically evaluate the efficacy and therapeutic value of PSMA CAR-T cells by analyzing the cytotoxicity against prostate tumor spheroids. In addition, the CAR-T cells were fluorescently labeled to visually identify the location of the T cells as cytotoxicity occurs, which may provide more meaningful information for assessing the functionality of the CAR-T cells. The proposed image cytometry method can overcome limitations placed on traditional methodologies to effectively assess cell-mediated 3D tumor spheroid cytotoxicity and efficiently generate time- and dose-dependent results.


Assuntos
Neoplasias da Próstata , Receptores de Antígenos Quiméricos , Masculino , Humanos , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/metabolismo , Imunoterapia Adotiva/métodos , Linfócitos T/metabolismo , Citometria por Imagem/métodos , Microambiente Tumoral
15.
Front Endocrinol (Lausanne) ; 14: 1106706, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36761187

RESUMO

Diabetic macular edema (DME) causes visual impairment in diabetic retinopathy (DR). Diabetes mellitus is a global epidemic and diabetic individuals are at risk of developing DR. Approximately 1 in 10 diabetic patients suffers from DME, which is the commonest cause of vision-threatening DR at primary-care screening. Furthermore, diabetes predisposes to a higher frequency and a younger onset of cataract, which further threatens vision in DME patients. Although cataract extraction is an effective cure, vision may still deteriorate following cataract surgery due to DME progression or recurrence, of which the risks are significantly higher than for patients without concurrent or previous history of DME at the time of operation. The management of pre-existing DME with visually significant cataract is a clinical conundrum. Deferring cataract surgery until DME is adequately treated is not ideal because of prolonged visual impairment and maturation of cataract jeopardizing surgical safety and monitoring of DR. On the other hand, the progression or recurrence of DME following prompt cataract surgery is a profound disappointment for patients and ophthalmic surgeons who had high expectations for postoperative visual improvement. Prescription of perioperative anti-inflammatory eye drops is effective in lowering the risk of new-onset DME after cataract surgery. However, management of concurrent DME at the time of cataract surgery is much more challenging because DME is unlikely to resolve spontaneously even with the aid of anti-inflammatory non-steroidal or steroid eye drops. A number of clinical trials using intravitreal injection of corticosteroids and anti-vascular endothelial growth factor (anti-VEGF) as first-line therapy have demonstrated safety and efficacy to treat DME. These drugs have also been administered perioperatively for the prevention of DME worsening in patients undergoing cataract surgery. This article reviews the scientific evidence to guide ophthalmologists on the efficacy and safety of various therapies for managing patients with DME who are particularly vulnerable to cataract surgery-induced inflammation, which disintegrates the blood-retinal barrier and egression of fluid in macular edema.


Assuntos
Extração de Catarata , Catarata , Diabetes Mellitus , Retinopatia Diabética , Edema Macular , Humanos , Retinopatia Diabética/complicações , Retinopatia Diabética/diagnóstico , Edema Macular/etiologia , Edema Macular/tratamento farmacológico , Edema Macular/cirurgia , Extração de Catarata/efeitos adversos , Anti-Inflamatórios/uso terapêutico , Catarata/complicações , Catarata/tratamento farmacológico , Soluções Oftálmicas/uso terapêutico , Transtornos da Visão/tratamento farmacológico , Diabetes Mellitus/tratamento farmacológico
16.
Sci Total Environ ; 872: 162236, 2023 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-36791857

RESUMO

The dinoflagellates Gambierdiscus and Fukuyoa can produce Ciguatoxins (CTXs) and Maitotoxins (MTXs) that lead to ciguatera poisoning (CP). The CP hotspots, however, do not directly relate to the occurrence of the ciguatoxic Gambierdiscus and Fukuyoa. Species-wide investigations often showed no association between CTX level and the molecular identity of the dinoflagellates. In the Pacific region, Kiribati is known as a CP hotspot, while Malaysia has only three CP outbreaks reported thus far. Although ciguatoxic strains of Gambierdiscus were isolated from both Kiribati and Malaysia, no solid evidence on the contribution of ciguatoxic strains to the incidence of CP outbreak was recorded. The present study aims to investigate the regional differences in CP risks through region-specific toxicological assessment of Gambierdiscus and Fukuyoa. A total of 19 strains of Gambierdiscus and a strain of Fukuyoa were analyzed by cytotoxicity assay of the neuro-2a cell line, hemolytic assay of fish erythrocytes, and high-resolution mass spectrometry. Gambierdiscus from both Kiribati and Malaysia showed detectable ciguatoxicity; however, the Kiribati strains were more hemolytic. Putative 44-methylgambierone was identified as part of the contributors to the hemolytic activity, and other unknown hydrophilic toxins produced can be potentially linked to higher CP incidence in Kiribati.


Assuntos
Ciguatera , Ciguatoxinas , Dinoflagellida , Animais , Dinoflagellida/química , Malásia , Ciguatoxinas/toxicidade , Ciguatera/epidemiologia , Linhagem Celular
17.
Mar Drugs ; 21(1)2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36662219

RESUMO

Dysfunctional autophagy is associated with various human diseases, e.g., cancer. The discovery of small molecules modulating autophagy with therapeutic potential could be significant. To this end, we screened the ability of a series of metabolites isolated from marine microorganisms to modulate autophagy. Anhydrodebromoaplysiatoxin (ADAT), a metabolite yielded by the marine red algae Gracilaria coronopifolia, inhibited autophagosome-lysosome fusion in mammalian cells, thereby inducing the accumulation of autophagosomes. Treatment of cells with ADAT alkalinized lysosomal pH. Interestingly, ADAT also activated the mTOR/p70S6K/FoxO3a signaling pathway, likely leading to the inhibition of autophagy induction. ADAT had little effect on apoptosis. Our results suggest that ADAT is a dichotomic autophagy inhibitor that inhibits both late-stage (autophagosome-lysosome fusion) and early-stage (autophagy induction) autophagy.


Assuntos
Autofagossomos , Autofagia , Animais , Humanos , Autofagossomos/metabolismo , Lisossomos , Mamíferos , Transdução de Sinais
18.
Clin Exp Ophthalmol ; 51(3): 229-242, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36594934

RESUMO

Recent evidence has demonstrated that the global public health burden of myopia is rising rapidly. Highly myopic eyes are associated with increased frequency of eye disorders that can lead to irreversible visual impairment. With recent technological advancement in ophthalmic imaging modalities, various macular complications associated with pathologic myopia are being elucidated. The development and progression of myopic chorioretinal atrophy, myopic macular neovascularization, myopic traction maculopathy and dome-shaped macula are vision-threatening myopic macular diseases. In order to overcome the challenges in managing patients with pathologic myopia, it is important to have a complete understanding in the natural course of these myopic macular diseases. Standardising the classification criteria of pathologic myopia is essential for enhancing clinical surveillance. Personalised pharmaceutical therapy and surgical interventions will help to optimise the treatment outcomes in patients suffering from these myopic macular diseases.


Assuntos
Macula Lutea , Miopia Degenerativa , Degeneração Retiniana , Doenças Retinianas , Humanos , Miopia Degenerativa/complicações , Miopia Degenerativa/diagnóstico , Miopia Degenerativa/epidemiologia , Estudos Retrospectivos , Doenças Retinianas/etiologia , Macula Lutea/patologia , Transtornos da Visão , Tomografia de Coerência Óptica
19.
Cytometry A ; 103(1): 27-38, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35869932

RESUMO

In the recent decade, chimeric antigen receptor (CAR)-T cell therapy has revolutionized strategies for cancer treatments due to its highly effective clinical efficacy and response for B cell malignancies. The success of CAR-T cell therapy has stimulated the increase in the research and development of various CAR constructs to target different tumor types. Therefore, a robust and efficient in vitro potency assay is needed to quickly identify potential CAR gene design from a library of construct candidates. Image cytometry methodologies have been utilized for various CAR-T cell-mediated cytotoxicity assay using different fluorescent labeling methods, mainly due to their ease-of-use, ability to capture cell images for verification, and higher throughput performance. In this work, we employed the Celigo Image Cytometer to evaluate and compare two CAR-T cell-mediated cytotoxicity assays using GFP-expressing or fluorescent dye-labeled myeloma and plasmacytoma cells. The GFP-based method demonstrated higher sensitivity in detecting CAR-T cell-mediated cytotoxicity when compared to the CMFDA/DAPI viability method. We have established the criteria and considerations for the selection of cytotoxicity assays that are fit-for-purpose to ensure the results produced are meaningful for the specific testing conditions.


Assuntos
Mieloma Múltiplo , Receptores de Antígenos Quiméricos , Humanos , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/metabolismo , Linfócitos T , Linhagem Celular Tumoral , Imunoterapia Adotiva/métodos
20.
J Clin Invest ; 132(13)2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35775486

RESUMO

Immunosuppressive cells accumulating in the tumor microenvironment constitute a formidable barrier that interferes with current immunotherapeutic approaches. A unifying feature of these tumor-associated immune and vascular endothelial cells appears to be the elevated expression of ectonucleotidase CD39, which in tandem with ecto-5'-nucleotidase CD73, catalyzes the conversion of extracellular ATP into adenosine. We glycoengineered an afucosylated anti-CD39 IgG2c and tested this reagent in mouse melanoma and colorectal tumor models. We identified major biological effects of this approach on cancer growth, associated with depletion of immunosuppressive cells, mediated through enhanced Fcγ receptor-directed (FcγR-directed), antibody-dependent cellular cytotoxicity (ADCC). Furthermore, regulatory/exhausted T cells lost CD39 expression, as a consequence of antibody-mediated trogocytosis. Most strikingly, tumor-associated macrophages and endothelial cells with high CD39 expression were effectively depleted following antibody treatment, thereby blocking angiogenesis. Tumor site-specific cellular modulation and lack of angiogenesis synergized with chemotherapy and anti-PD-L1 immunotherapy in experimental tumor models. We conclude that depleting suppressive cells and targeting tumor vasculature, through administration of afucosylated anti-CD39 antibody and the activation of ADCC, comprises an improved, purinergic system-modulating strategy for cancer therapy.


Assuntos
Apirase , Neoplasias , Animais , Antígenos CD/metabolismo , Células Endoteliais/metabolismo , Camundongos , Neovascularização Patológica/genética , Microambiente Tumoral
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