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1.
Genes Chromosomes Cancer ; 63(7): e23257, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39031442

RESUMEN

Gene panel sequencing has become a common diagnostic tool for detecting somatically acquired mutations in myeloid neoplasms. However, many panels have restricted content, provide insufficient sensitivity levels, or lack clinically validated workflows. We here describe the development and validation of the Genomic Medicine Sweden myeloid gene panel (GMS-MGP), a capture-based 191 gene panel including mandatory genes in contemporary guidelines as well as emerging candidates. The GMS-MGP displayed uniform coverage across all targets, including recognized difficult GC-rich areas. The validation of 117 previously described somatic variants showed a 100% concordance with a limit-of-detection of a 0.5% variant allele frequency (VAF), achieved by utilizing error correction and filtering against a panel-of-normals. A national interlaboratory comparison investigating 56 somatic variants demonstrated highly concordant results in both detection rate and reported VAFs. In addition, prospective analysis of 323 patients analyzed with the GMS-MGP as part of standard-of-care identified clinically significant genes as well as recurrent mutations in less well-studied genes. In conclusion, the GMS-MGP workflow supports sensitive detection of all clinically relevant genes, facilitates novel findings, and is, based on the capture-based design, easy to update once new guidelines become available. The GMS-MGP provides an important step toward nationally harmonized precision diagnostics of myeloid malignancies.


Asunto(s)
Medicina de Precisión , Humanos , Medicina de Precisión/métodos , Mutación , Suecia , Pruebas Genéticas/métodos , Pruebas Genéticas/normas , Trastornos Mieloproliferativos/genética , Trastornos Mieloproliferativos/diagnóstico , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Frecuencia de los Genes
2.
Invest Ophthalmol Vis Sci ; 64(14): 34, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-38010699

RESUMEN

Purpose: To investigate whether nicotinamide (NAM) modulates retinal vasculature in glaucoma. Methods: This was a prospective controlled clinical trial investigating animal and human histopathology. Participants included normotensive and ocular hypertensive rats, postmortem human ocular tissue, glaucoma patients (n = 90), and healthy controls (n = 30). The study utilized histopathology, computer-assisted retinal vasculature analysis, optical coherence tomography angiography (OCTA), and NAM treatment. The main outcome measures included retinal vascular parameters in rats as assessed by AngioTool; retinal vasculature integrity in rats and humans as assessed by histopathology, antibody-staining, and ImageJ-based measurements; and retinal perfusion density (PD) and flux index in humans as assessed by OCTA. Results: A number of vessel parameters were altered in ocular hypertension/glaucoma compared to healthy controls. NAM treatment improved the retinal vasculature in ocular hypertensive rats, with an increase in mean vessel area, percentage area covered by vessels, total vessel length, total junctions, and junction density as assessed by AngioTool (all P < 0.05); vessel wall integrity as assessed by VE-cadherin antibody staining was also improved (P < 0.01). In humans, as assessed by OCTA, increases in PD in the optic nerve head and macula complete image (0.7%, P = 0.04 and 1.0%, P = 0.002, respectively) in healthy controls, and an increase in the temporal quadrant of the macula (0.7%, P = 0.02) in glaucoma patients was seen after NAM treatment. Conclusions: NAM can prevent retinal vascular damage in an animal model of glaucoma. After NAM treatment, glaucoma patients and healthy controls demonstrated a small increase in retinal vessel parameters as assessed by OCTA.


Asunto(s)
Glaucoma de Ángulo Abierto , Glaucoma , Hipertensión Ocular , Disco Óptico , Animales , Humanos , Ratas , Angiografía con Fluoresceína/métodos , Disco Óptico/irrigación sanguínea , Estudios Prospectivos , Vasos Retinianos/patología , Tomografía de Coherencia Óptica/métodos , Campos Visuales
3.
Adv Radiat Oncol ; 8(3): 101152, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36896210

RESUMEN

Purpose: To develop a prognostic score that correlates to a low, medium, and high incidence of treatment failure after plaque brachytherapy of uveal melanoma (UM). Methods and Materials: All patients who have received plaque brachytherapy for posterior UM at St. Erik Eye Hospital in Stockholm, Sweden from 1995 through 2019 were included (n = 1636). Treatment failure was defined as tumor recurrence, lack of tumor regression, or any other condition requiring a secondary transpupillary thermotherapy (TTT), plaque brachytherapy, or enucleation. The total sample was randomized into 1 training and 1 validation cohort, and a prognostic score for the risk for treatment failure was developed. Results: In multivariate Cox regression, low visual acuity, tumor distance to the optic disc ≤2 mm, American Joint Committee on Cancer (AJCC) stage, and a tumor apical thickness of >4 (for Ruthenium-106) or >9 mm (for Iodine-125) were independent predictors of treatment failure. No reliable threshold could be identified for tumor diameter or cancer stage. In competing risk analyses of the validation cohort, the cumulative incidence of treatment failure, as well as of secondary enucleation, increased with the prognostic score: In the low, intermediate, and high-risk classes, the 10-year incidence of treatment failure was 19, 28, and 35% and of secondary enucleation 7, 19, and 25 %, respectively. Conclusions: Low visual acuity, American Joint Committee on Cancer stage, tumor thickness, and tumor distance to the optic disc are independent predictors of treatment failure after plaque brachytherapy for UM. A prognostic score was devised that identifies low, medium, and high risk for treatment failure.

4.
Trials ; 24(1): 230, 2023 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-36966349

RESUMEN

BACKGROUND: Uveal melanoma is the most common primary intraocular tumor in adults. In Sweden, at least 100 patients are diagnosed with the disease each year. Almost half of the patients develop metastases, with a median survival time of 1 year once metastases are detected. The primary ocular tumor is typically treated with either enucleation or brachytherapy, and no adjuvant treatment is added. Melatonin is an indolamine hormone that has improved survival in previous trials with patients diagnosed with various cancers, including advanced cutaneous melanoma. Side effects have been mild. We aim to investigate if adjuvant treatment with melatonin for 5 years following diagnosis of non-metastasized uveal melanoma can decrease the occurrence of metastases. METHODS: An open-label, prospective, 5-year randomized clinical trial (RCT) will be conducted at St. Erik Eye Hospital. One hundred patients recently diagnosed with non-metastatic uveal melanoma will be randomized to either treatment with adjuvant melatonin 20 mg (4 tablets of 5 mg) at 10 pm for 5 years, or to standard follow-up (control group). The primary outcome measurement is the relative risk for having developed metastases 5 years after randomization. The secondary outcomes are overall survival, risk of developing other cancers, overall survival after detection of metastases, and differences in the occurrence of adverse events (AE) and serious adverse events (SAE) between the groups. DISCUSSION: Melatonin has been found to positively impact our immune system, inhibit angiogenesis, stimulate apoptosis in malignant cells, and act as a potent antioxidant. Previous clinical trials have used similar doses of melatonin with positive results, particularly in advanced stages of cancer. Previous animal and human studies have found the toxicity of the hormone to be low. Considering the potential benefits and limited risks of melatonin, as well as its global availability, it may be a suitable candidate for an adjuvant treatment in patients with uveal melanoma. TRIAL REGISTRATION: Our trial protocol has been approved and registered by the Swedish Medical Products Agency on June 22, 2022 (EudraCT 2022-500,307-49-00). Our trial registration number is NCT05502900, and the date of registration is August 16, 2022.


Asunto(s)
Melanoma , Melatonina , Neoplasias Cutáneas , Neoplasias de la Úvea , Adulto , Humanos , Melatonina/efectos adversos , Melanoma/tratamiento farmacológico , Melanoma/patología , Neoplasias de la Úvea/tratamiento farmacológico , Ensayos Clínicos Controlados Aleatorios como Asunto , Ensayos Clínicos Fase III como Asunto
5.
Acta Neuropathol Commun ; 11(1): 18, 2023 01 22.
Artículo en Inglés | MEDLINE | ID: mdl-36681854

RESUMEN

Glaucoma is the leading cause of irreversible blindness and is a major health and economic burden. Current treatments do not address the neurodegenerative component of glaucoma. In animal models of glaucoma, the capacity to maintain retinal nicotinamide adenine dinucleotide (NAD) pools declines early during disease pathogenesis. Treatment with nicotinamide, an NAD precursor through the NAD salvage pathway, robustly protects against neurodegeneration in a number of glaucoma models and improves vision in existing glaucoma patients. However, it remains unknown in humans what retinal cell types are able to process nicotinamide to NAD and how these are affected in glaucoma. To address this, we utilized publicly available RNA-sequencing data (bulk, single cell, and single nucleus) and antibody labelling in highly preserved enucleated human eyes to identify expression of NAD synthesizing enzyme machinery. This identifies that the neural retina favors expression of the NAD salvage pathway, and that retinal ganglion cells are particularly enriched for these enzymes. NMNAT2, a key terminal enzyme in the salvage pathway, is predominantly expressed in retinal ganglion cell relevant layers of the retina and declines in glaucoma. These findings suggest that human retinal ganglion cells can directly utilize nicotinamide and could maintain a capacity to do so in glaucoma, showing promise for ongoing clinical trials.


Asunto(s)
Glaucoma , NAD , Animales , Humanos , NAD/metabolismo , Niacinamida/metabolismo , Retina/patología , Glaucoma/patología , Nervio Óptico/patología , Células Ganglionares de la Retina/patología
6.
Acta Neuropathol Commun ; 10(1): 118, 2022 08 19.
Artículo en Inglés | MEDLINE | ID: mdl-35986368

RESUMEN

Neuroinflammation is recognized as a key component of neurodegenerative disease. In glaucoma, a common neurodegenerative disease and the leading cause of irreversible blindness, the evidence for neuroinflammation in patients is lacking. Animal models have demonstrated significant pro-inflammatory activation of resident glia in the retina, as well as influx of blood-derived monocytes and pro-inflammatory factors. Confirmation of this in human donor tissue has been challenging due to a lack of well-preserved and well-characterized post-mortem tissue. To address this we utilize archived, wax embedded eyes fixed immediately following enucleation from living glaucoma patients. We compared glaucoma to control eyes (enucleated for uveal melanoma where the tumor did not impact the central retina or optic nerve). We performed immunolabelling for neurodegenerative and glial markers (CD45, CD163, IBA1, GFAP, Vimentin) which were quantified by high-resolution light microscopy and image analysis in FIJI. Glaucoma eyes demonstrated significant neural loss consistent with advanced neurodegeneration. IBA1 and GFAP were significantly increased in the retina and optic nerve head of the glaucomatous eyes indicating that significant neuroinflammation had occurred which support findings in animal models. Inflammation is a treatable symptom of many diseases and as such, identification of earlier inflammatory processes in glaucoma could be important for potential future treatment options.


Asunto(s)
Glaucoma , Enfermedades Neurodegenerativas , Animales , Glaucoma/patología , Glaucoma/cirugía , Humanos , Enfermedades Neurodegenerativas/patología , Enfermedades Neuroinflamatorias , Nervio Óptico/patología , Retina/patología
7.
BMC Cancer ; 22(1): 398, 2022 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-35413810

RESUMEN

BACKGROUND: Uveal melanoma is a rare form of cancer with high mortality. The incidence of metastases is attributed to early seeding of micrometastases from the eye to distant organs, primarily the liver. Once these seeded clusters of dormant tumor cells grow into larger radiologically detectable macrometastases, median patient survival is about 1 year. Melatonin is an important hormone for synchronizing circadian rhythms. It is also involved in other aspects of human physiology and may offer therapeutic benefits for a variety of diseases including cancer. METHODS: Articles involving the physiological effects of melatonin, pharmacokinetics, and previous use in cancer studies were acquired using a comprehensive literature search in the Medline (PubMed) and Web of Science databases. In total, 147 publications were selected and included in the review. RESULTS: Melatonin has been observed to suppress the growth of cancer cells, inhibit metastatic spread, enhance immune system functions, and act as an anti-inflammatory in both in vitro and in vivo models. Melatonin may also enhance the efficacy of cancer treatments such as immuno- and chemotherapy. Numerous studies have shown promising results for oral melatonin supplementation in patients with other forms of cancer including cutaneous malignant melanoma. Cell line and animal studies support a hypothesis in which similar benefits may exist for uveal melanoma. CONCLUSIONS: Given its low cost, good safety profile, and limited side effects, there may be potential for the use of melatonin as an adjuvant oncostatic treatment. Future avenues of research could include clinical trials to evaluate the effect of melatonin in prevention of macrometastases of uveal melanoma.


Asunto(s)
Melanoma , Melatonina , Neoplasias de la Úvea , Humanos , Melanoma/patología , Melatonina/farmacología , Melatonina/uso terapéutico , Neoplasias de la Úvea/patología
8.
Sci Total Environ ; 778: 146192, 2021 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-33714836

RESUMEN

On December 13, 2019, the Yale School of Public Health hosted a symposium titled "Per- and Polyfluoroalkyl Substances (PFAS): Challenges and Opportunities" in New Haven, Connecticut. The meeting focused on the current state of the science on these chemicals, highlighted the challenges unique to PFAS, and explored promising opportunities for addressing them. It brought together participants from Yale University, the National Institute of Environmental Health Sciences, the University of Massachusetts Amherst, the University of Connecticut, the Connecticut Agricultural Experiment Station, the Connecticut Departments of Public Health and Energy and Environmental Protection, and the public and private sectors. Presentations during the symposium centered around several primary themes. The first reviewed the current state of the science on the health effects associated with PFAS exposure and noted key areas that warranted future research. As research in this field relies on specialized laboratory analyses, the second theme considered commercially available methods for PFAS analysis as well as several emerging analytical approaches that support health studies and facilitate the investigation of a broader range of PFAS. Since mitigation of PFAS exposure requires prevention and cleanup of contamination, the third theme highlighted new nanotechnology-enabled PFAS remediation technologies and explored the potential of green chemistry to develop safer alternatives to PFAS. The fourth theme covered collaborative efforts to assess the vulnerability of in-state private wells and small public water supplies to PFAS contamination by adjacent landfills, and the fifth focused on strategies that promote successful community engagement. This symposium supported a unique interdisciplinary coalition established during the development of Connecticut's PFAS Action Plan, and discussions occurring throughout the symposium revealed opportunities for collaborations among Connecticut scientists, state and local officials, and community advocates. In doing so, it bolstered the State of Connecticut's efforts to implement the ambitious initiatives that its PFAS Action Plan recommends.

9.
ACS Appl Mater Interfaces ; 11(14): 13304-13318, 2019 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-30933469

RESUMEN

Upconversion (UC) of sub-bandgap photons extends the effective light absorption range of photovoltaic and photocatalytic devices, allowing them to reach higher conversion efficiencies. Recent advances in polymer host materials make it possible to translate triplet-triplet annihilation (TTA)-UC, the UC mechanism most suitable for this purpose, to solid films that can be integrated into devices. The promise of these films is currently limited by the narrow light absorption of TTA-UC sensitizer chromophores, but incorporating multiple sensitizers into layered film systems presents a promising strategy for producing UC materials with broadened light absorption. This strategy is herein applied for photocatalytic air purification, demonstrating its use in a real-world application for the first time. We superimpose optimized red-to-blue and green-to-blue UC films within dual-layer systems and develop a new photocatalyst compatible with their fluorescence emission. By integrating the dual-layer UC film systems with films of this photocatalyst, we produce the first devices that use TTA-UC to harness both red and green sub-bandgap photons for hydroxyl radical generation and photocatalytic degradation of gaseous acetaldehyde, a model volatile organic compound (VOC). Under white light-emitting diode excitation, the dual-layer film systems' broadened light absorption enhances their devices' photocatalytic degradation efficiency, enabling them to degrade twice as much acetaldehyde as their single-sensitizer counterparts. We show that as a result of the different absorption profiles of the two sensitizers, the film order significantly impacts UC fluorescence and VOC degradation. By probing the influence of the excitation light source, excitation geometry, and chromophore spectral overlap on the film systems' UC performance, we propose a framework for the design of multilayer TTA-UC film systems suitable for integration with a variety of photovoltaic and photocatalytic devices.

10.
Development ; 146(1)2019 01 09.
Artículo en Inglés | MEDLINE | ID: mdl-30567931

RESUMEN

Numerous protocols have been described for producing neural retina from human pluripotent stem cells (hPSCs), many of which are based on the culture of 3D organoids. Although nearly all such methods yield at least partial segments of retinal structure with a mature appearance, variabilities exist within and between organoids that can change over a protracted time course of differentiation. Adding to this complexity are potential differences in the composition and configuration of retinal organoids when viewed across multiple differentiations and hPSC lines. In an effort to understand better the current capabilities and limitations of these cultures, we generated retinal organoids from 16 hPSC lines and monitored their appearance and structural organization over time by light microscopy, immunocytochemistry, metabolic imaging and electron microscopy. We also employed optical coherence tomography and 3D imaging techniques to assess and compare whole or broad regions of organoids to avoid selection bias. Results from this study led to the development of a practical staging system to reduce inconsistencies in retinal organoid cultures and increase rigor when utilizing them in developmental studies, disease modeling and transplantation.


Asunto(s)
Organoides/citología , Células Madre Pluripotentes/citología , Retina/citología , Diferenciación Celular , Línea Celular , Proliferación Celular , Forma de la Célula , Células Ependimogliales/citología , Células Ependimogliales/metabolismo , Humanos , Interneuronas/citología , Interneuronas/metabolismo , Modelos Biológicos , Células-Madre Neurales/citología , Células-Madre Neurales/metabolismo , Células Madre Pluripotentes/metabolismo , Células Madre Pluripotentes/ultraestructura , Reproducibilidad de los Resultados , Células Ganglionares de la Retina/citología , Células Ganglionares de la Retina/metabolismo , Sinapsis/metabolismo , Tomografía de Coherencia Óptica
11.
ACS Appl Mater Interfaces ; 10(10): 8985-8992, 2018 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-29441781

RESUMEN

Triplet-triplet annihilation upconversion (TTA-UC) has recently drawn widespread interest for its capacity to harvest low-energy photons and to broaden the absorption spectra of photonic devices, such as solar cells. Although conceptually promising, effective integration of TTA-UC materials into practical devices has been difficult due to the diffusive and anoxic conditions required in TTA-UC host media. Of the solid-state host materials investigated, rubbery polymers facilitate the highest TTA-UC efficiency. To date, however, their need for long-term oxygen protection has limited rubbery polymers to rigid film architectures that forfeit their intrinsic flexibility. This study introduces a new multilayer thin-film architecture, in which scalable solution processing techniques are employed to fabricate flexible, photostable, and efficient TTA-UC thin films containing layers of oxygen barrier and host polymers. This breakthrough material design marks a crucial advance toward TTA-UC integration within rigid and flexible devices alike. Moreover, it introduces new opportunities in unexplored applications such as anticounterfeiting. Soft lithography is incorporated into the film fabrication process to pattern TTA-UC host layers with a broad range of high-resolution microscale designs, and superimposing host layers with customized absorption, emission, and patterning ultimately produces proof-of-concept anticounterfeiting labels with advanced excitation-dependent photoluminescent security features.

12.
Environ Sci Technol ; 50(20): 11184-11192, 2016 10 18.
Artículo en Inglés | MEDLINE | ID: mdl-27684445

RESUMEN

This study demonstrates the first reported photocatalytic decomposition of an indoor air pollutant, acetaldehyde, using low-energy, sub-bandgap photons harnessed through sensitized triplet-triplet annihilation (TTA) upconversion (UC). To utilize low-intensity noncoherent indoor light and maximize photocatalytic activity, we designed a plasmon-enhanced sub-bandgap photocatalyst device consisting of two main components: (1) TTA-UC rubbery polymer films containing broad-band plasmonic particles (Ag-SiO2) to upconvert sub-bandgap photons, and (2) nanodiamond (ND)-loaded WO3 as a visible-light photocatalyst composite. Effective decomposition of acetaldehyde was achieved using ND/WO3 (Eg = 2.8 eV) coupled with TTA-UC polymer films that emit blue photons (λEm = 425 nm, 2.92 eV) upconverted from green photons (λEx = 532 nm, 2.33 eV), which are wasted in most environmental photocatalysis. The overall photocatalytic efficiency was amplified by the broad-band surface plasmon resonance of AgNP-SiO2 particles incorporated into the TTA-UC films.


Asunto(s)
Dióxido de Silicio , Compuestos Orgánicos Volátiles , Catálisis , Luz , Fotones
13.
Stem Cells ; 34(11): 2625-2634, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27301076

RESUMEN

Few gene targets of Visual System Homeobox 2 (VSX2) have been identified despite its broad and critical role in the maintenance of neural retina (NR) fate during early retinogenesis. We performed VSX2 ChIP-seq and ChIP-PCR assays on early stage optic vesicle-like structures (OVs) derived from human iPS cells (hiPSCs), which highlighted WNT pathway genes as direct regulatory targets of VSX2. Examination of early NR patterning in hiPSC-OVs from a patient with a functional null mutation in VSX2 revealed mis-expression and upregulation of WNT pathway components and retinal pigmented epithelium (RPE) markers in comparison to control hiPSC-OVs. Furthermore, pharmacological inhibition of WNT signaling rescued the early mutant phenotype, whereas augmentation of WNT signaling in control hiPSC-OVs phenocopied the mutant. These findings reveal an important role for VSX2 as a regulator of WNT signaling and suggest that VSX2 may act to maintain NR identity at the expense of RPE in part by direct repression of WNT pathway constituents. Stem Cells 2016;34:2625-2634.


Asunto(s)
Tipificación del Cuerpo/genética , Proteínas de Homeodominio/genética , Células Madre Pluripotentes Inducidas/metabolismo , Microftalmía/genética , Epitelio Pigmentado de la Retina/metabolismo , Factores de Transcripción/genética , Proteína Wnt1/genética , Sustitución de Aminoácidos , Benzotiazoles/farmacología , Biomarcadores/metabolismo , Diferenciación Celular , Cuerpos Embrioides/efectos de los fármacos , Cuerpos Embrioides/metabolismo , Cuerpos Embrioides/patología , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Proteínas de Homeodominio/metabolismo , Humanos , Células Madre Pluripotentes Inducidas/efectos de los fármacos , Células Madre Pluripotentes Inducidas/patología , Factor de Transcripción Asociado a Microftalmía/genética , Factor de Transcripción Asociado a Microftalmía/metabolismo , Microftalmía/metabolismo , Microftalmía/patología , Mutación , Fenotipo , Cultivo Primario de Células , Piridinas/farmacología , Pirimidinas/farmacología , Epitelio Pigmentado de la Retina/efectos de los fármacos , Epitelio Pigmentado de la Retina/patología , Factores de Transcripción/metabolismo , Vía de Señalización Wnt/efectos de los fármacos , Proteína Wnt1/agonistas , Proteína Wnt1/antagonistas & inhibidores , Proteína Wnt1/metabolismo
14.
Sci Rep ; 6: 24297, 2016 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-27075635

RESUMEN

In this work, we demonstrate that signal-masking reagents together with appropriate capture antibody carriers can eliminate the washing steps in sandwich immunoassays. A flotation immunoassay (FI) platform was developed with horseradish peroxidase chemiluminescence as the reporter system, the dye Brilliant Blue FCF as the signal-masking reagent, and buoyant silica micro-bubbles as the capture antibody carriers. Only reporters captured on micro-bubbles float above the dye and become visible in an analyte-dependent manner. These FIs are capable of detecting proteins down to attomole levels and as few as 10(6) virus particles. This signal-masking strategy represents a novel approach to simple, sensitive and quantitative immunoassays in both laboratory and point-of-care settings.


Asunto(s)
Inmunoensayo/métodos , Manejo de Especímenes/métodos , Mediciones Luminiscentes , Sistemas de Atención de Punto , Proteínas/análisis , Sensibilidad y Especificidad
15.
Anal Chem ; 87(23): 11660-5, 2015 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-26456715

RESUMEN

We introduce the modification of bacteriophage particles with aptamers for use as bioanalytical reporters, and demonstrate the use of these particles in ultrasensitive lateral flow assays. M13 phage displaying an in vivo biotinylatable peptide (AviTag) genetically fused to the phage tail protein pIII were used as reporter particle scaffolds, with biotinylated aptamers attached via avidin-biotin linkages, and horseradish peroxidase (HRP) reporter enzymes covalently attached to the pVIII coat protein. These modified viral nanoparticles were used in immunochromatographic sandwich assays for the direct detection of IgE and of the penicillin-binding protein from Staphylococcus aureus (PBP2a). We also developed an additional lateral flow assay for IgE, in which the analyte is sandwiched between immobilized anti-IgE antibodies and aptamer-bearing reporter phage modified with HRP. The limit of detection of this LFA was 0.13 ng/mL IgE, ∼100 times lower than those of previously reported IgE assays.


Asunto(s)
Aptámeros de Péptidos/análisis , Aptámeros de Péptidos/química , Bacteriófago M13/química , Bioensayo , Inmunoglobulina E/análisis , Proteínas de Unión a las Penicilinas/análisis , Staphylococcus aureus/química
16.
PLoS One ; 10(5): e0126571, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25978622

RESUMEN

Noroviruses are recognized worldwide as the principal cause of acute, non-bacterial gastroenteritis, resulting in 19-21 million cases of disease every year in the United States. Noroviruses have a very low infectious dose, a short incubation period, high resistance to traditional disinfection techniques and multiple modes of transmission, making early, point-of-care detection essential for controlling the spread of the disease. The traditional diagnostic tools, electron microscopy, RT-PCR and ELISA require sophisticated and expensive instrumentation, and are considered too laborious and slow to be useful during severe outbreaks. In this paper we describe the development of a new, rapid and sensitive lateral-flow assay using labeled phage particles for the detection of the prototypical norovirus GI.1 (Norwalk), with a limit of detection of 107 virus-like particles per mL, one hundred-fold lower than a conventional gold nanoparticle lateral-flow assay using the same antibody pair.


Asunto(s)
Bacteriófagos/metabolismo , Bioensayo/métodos , Infecciones por Caliciviridae/diagnóstico , Infecciones por Caliciviridae/virología , Nanopartículas/metabolismo , Norovirus/aislamiento & purificación , Escherichia coli/genética , Gastroenteritis/diagnóstico , Gastroenteritis/virología , Humanos , Sensibilidad y Especificidad , Estados Unidos
17.
ACS Appl Mater Interfaces ; 7(4): 2891-8, 2015 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-25581289

RESUMEN

We demonstrated a lateral flow immunoassay (LFA) for detection of viruses using fluorescently labeled M13 bacteriophage as reporters and single-reporter counting as the readout. AviTag-biotinylated M13 phage were functionalized with antibodies using avidin-biotin conjugation and fluorescently labeled with AlexaFluor 555. Individual phage bound to target viruses (here MS2 as a model) captured on an LFA membrane strip were imaged using epi-fluorescence microscopy. Using automated image processing, we counted the number of bound phage in micrographs as a function of target concentration. The resultant assay was more sensitive than enzyme-linked immunosorbent assays and traditional colloidal-gold nanoparticle LFAs for direct detection of viruses.


Asunto(s)
Bacteriófago M13/química , Inmunoensayo/métodos , Virus/química , Bacteriófago M13/aislamiento & purificación , Biotinilación , Colorantes Fluorescentes/química , Genes Reporteros , Inmunoensayo/instrumentación , Coloración y Etiquetado , Virus/aislamiento & purificación
18.
Anal Chem ; 86(19): 9481-8, 2014 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-25247754

RESUMEN

Demand for highly sensitive, robust diagnostics and environmental monitoring methods has led to extensive research in improving reporter technologies. Inorganic phosphorescent materials exhibiting persistent luminescence are commonly found in electroluminescent displays and glowing paints but are not widely used as reporters in diagnostic assays. Persistent luminescence nanoparticles (PLNPs) offer advantages over conventional photoluminescent probes, including the potential for enhanced sensitivity by collecting time-resolved measurements or images with decreased background autofluorescence while eliminating the need for expensive optical hardware, superior resistance to photobleaching, amenability to quantitation, and facile bioconjugation schemes. We isolated rare-earth doped strontium aluminate PLNPs from larger-particle commercial materials by wet milling and differential sedimentation and water-stabilized the particles by silica encapsulation using a modified Stöber process. Surface treatment with aldehyde silane followed by reductive amination with heterobifunctional amine-poly(ethylene glycol)-carboxyl allowed covalent attachment of proteins to the particles using standard carbodiimide chemistry. NeutrAvidin PLNPs were used in lateral flow assays (LFAs) with biotinylated lysozyme as a model analyte in buffer and monoclonal anti-lysozyme HyHEL-5 antibodies at the test line. Preliminary experiments revealed a limit of detection below 100 pg/mL using the NeutrAvidin PLNPs, which was approximately an order of magnitude more sensitive than colloidal gold.


Asunto(s)
Aluminio/química , Bioensayo , Nanopartículas del Metal/química , Muramidasa/análisis , Estroncio/química , Animales , Anticuerpos Monoclonales/química , Avidina/química , Biotina/química , Biotinilación , Carbodiimidas/química , Pollos , Oro Coloide/química , Límite de Detección , Luminiscencia , Muramidasa/química , Dióxido de Silicio/química
19.
Anal Chem ; 86(18): 9029-35, 2014 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-25133758

RESUMEN

Point-of-care detection of pathogens is medically valuable but poses challenging trade-offs between instrument complexity and clinical and analytical sensitivity. Here we introduce a diagnostic platform utilizing lithographically fabricated micron-scale forms of cubic retroreflectors, arguably one of the most optically detectable human artifacts, as reporter labels for use in sensitive immunoassays. We demonstrate the applicability of this novel optical label in a simple assay format in which retroreflector cubes are first mixed with the sample. The cubes are then allowed to settle onto an immuno-capture surface, followed by inversion for gravity-driven removal of nonspecifically bound cubes. Cubes bridged to the capture surface by the analyte are detected using inexpensive, low-numerical aperture optics. For model bacterial and viral pathogens, sensitivity in 10% human serum was found to be 10(4) bacterial cells/mL and 10(4) virus particles/mL, consistent with clinical utility.


Asunto(s)
Bacterias/aislamiento & purificación , Inmunoensayo , Técnicas Microbiológicas/métodos , Virus/aislamiento & purificación , Anticuerpos Inmovilizados/química , Anticuerpos Inmovilizados/inmunología , Bacterias/inmunología , Escherichia coli/inmunología , Escherichia coli/aislamiento & purificación , Humanos , Levivirus/inmunología , Levivirus/aislamiento & purificación , Sistemas de Atención de Punto , Polipropilenos/química , Virus/inmunología
20.
Biotechnol Lett ; 36(9): 1863-8, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24930095

RESUMEN

We report a novel, modular approach to immuno-detection based on antibody recognition and PCR read-out that employs antibody-conjugated bacteriophage and easily-manipulated non-pathogenic viruses as affinity agents. Our platform employs phage genetically tagged for in vivo biotinylation during phage maturation that can easily be linked, through avidin, to any biotinylated affinity agent, including full-length antibodies, peptides, lectins or aptamers. The presence of analyte is reported with high sensitivity through real-time PCR. This approach avoids the need to clone antibody-encoding DNA fragments, allows the use of full-length, high affinity antibodies and, by having DNA reporters naturally encapsulated inside the bacteriophage, greatly reduces nonspecific binding of DNA. We validate the efficacy of this new approach through the detection of Vascular Endothelial Growth Factor, a known angiogenic cancer biomarker protein, at attomolar concentrations in bronchoalveolar lavage fluid.


Asunto(s)
Bacteriófagos/genética , Biotinilación , Nanopartículas , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Anticuerpos Antivirales/metabolismo , Humanos , Inmunoensayo/métodos , Lectinas/metabolismo , Péptidos/metabolismo , Unión Proteica , Sensibilidad y Especificidad , Factor A de Crecimiento Endotelial Vascular/análisis
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