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1.
Am J Med Genet A ; : e63655, 2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38711238

RESUMEN

The association of early-onset non-progressive ataxia and miosis is an extremely rare phenotypic entity occasionally reported in the literature. To date, only one family (two siblings and their mother) has benefited from a genetic diagnosis by the identification of a missense heterozygous variant (p.Arg36Cys) in the ITPR1 gene. This gene encodes the inositol 1,4,5-trisphosphate receptor type 1, an intracellular channel that mediates calcium release from the endoplasmic reticulum. Deleterious variants in this gene are known to be associated with two types of spinocerebellar ataxia, SCA15 and SCA29, and with Gillespie syndrome that is associated with ataxia, partial iris hypoplasia, and intellectual disability. In this work, we describe a novel individual carrying a heterozygous missense variant (p.Arg36Pro) at the same position in the N-terminal suppressor domain of ITPR1 as the family previously reported, with the same phenotype associating early-onset non-progressive ataxia and miosis. This second report confirms the implication of ITPR1 in the miosis-ataxia syndrome and therefore broadens the clinical spectrum of the gene. Moreover, the high specificity of the phenotype makes it a recognizable syndrome of genetic origin.

2.
Ophthalmol Ther ; 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38625500

RESUMEN

INTRODUCTION: The aim of this work is to evaluate the real-world outcomes of the reinforced treat-and-extend (RTE) protocol for the treatment of exudative age-related macular degeneration with intravitreal injections of aflibercept or ranibizumab (anti-vascular endothelial growth factor therapies). METHODS: This was a retrospective review of patients from two tertiary ophthalmology centers in France initiating the RTE protocol between February 2018 and June 2021. The primary outcome was change in best-corrected visual acuity (BCVA) after 24 months. Secondary outcomes were change in central retinal thickness (CRT), recurrence, and management-related factors (injection interval, number of injections/consultations). Outcomes were additionally evaluated after protocol changes (strict versus modified RTE protocol groups). RESULTS: Sixty-eight patients (72 eyes) were included (68% females; mean age 82.2 ± 7.8 years). After 24 months, mean BCVA significantly improved (65.22 ± 14 vs. 71.96 ± 13 Early Treatment Diabetic Retinopathy Study letters; p < 0.001) and CRT significantly decreased (388.6 ± 104 vs. 278.8 ± 51 µM; p < 0.001) with 21% of eyes showing signs of exudation. Over the 24 months, a mean total of 14.9 ± 4.0 injections and 8.6 ± 1.4 consultations were performed. Mean 24-month injection interval was 7.9 ± 2.3 weeks. Initial and 24-month ophthalmic outcomes for eyes in the strict (47%) versus modified (53%) groups were not significantly different, but mean time interval to first recurrence of disease activity was significantly shorter for the modified group (7.3 ± 2.4 vs. 9.9 ± 2.5 weeks; p < 0.001). Patients in the strict RTE group received significantly less injections (13.9 ± 3.6 vs. 16.5 ± 3.9; p = 0.006) and mean 24-month injection interval was significantly longer (9.5 ± 2.7 vs. 6.5 ± 2.1 weeks; p < 0.001). Consultation number was similar (8.5 ± 1.9 vs. 8.8 ± 1.6; p = 0.93). Treatment with aflibercept versus ranibizumab did not influence ophthalmic or management outcomes. CONCLUSIONS: The RTE protocol, even when modified, reduced consultations but improved ophthalmic outcomes. The RTE protocol could reduce hospital visits and overall burden while also encouraging better patient compliance. Video Abstract available for this article. VIDEO ABSTRACT: Vincent Soler and François-Philippe Roubelat summarize the Reinforced Treat-and-Extend Protocol and main results (MP4 225022 KB).

3.
NPJ Microgravity ; 10(1): 4, 2024 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-38212301

RESUMEN

After exposure to microgravity, astronauts undergo microgravity-induced thoraco-cephalic fluid shift, which may lead to ocular changes called "spaceflight associated neuro-ocular syndrome" (SANS). The onset of SANS may be multifactorial, including a potential elevation in intracranial pressure. Moreover, little is known about the impact of spaceflight on SANS in women due to the fact that fewer female astronauts have spent time in long-term missions. The objective is to determine whether similar ophthalmological changes occur in healthy women after short-term exposure to microgravity. The auto-refractometer was used to determine objective refraction. The best corrected distance visual acuity was assessed with a Monoyer chart. The ocular axial length was assessed using optical biometry. The applanation tonometry was used to determine intraocular pressure. Peripapillary retinal nerve fibre layer thickness (pRNFLT), macular total retinal thickness, and ganglion cell complex (GCC) were measured using optical coherence tomography. Ocular axial length is reduced after DI. pRNFL is thickest after DI specifically in the temporal, temporal-inferior, and nasal-inferior quadrants. Macular total retinal at the inferior quadrant of the 6-mm ring is thickest after DI. Global GCC is thinnest after DI. In this study, 5 days of DI induces slight but significant ophthalmological changes in women. However, these subtle changes do not correspond to criteria defined in SANS.

4.
Int Ophthalmol ; 43(7): 2545-2556, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36920634

RESUMEN

PURPOSE: To review management, treatment, and outcomes of patients with necrotizing herpetic retinitis (NHR) to propose an algorithm for first-line management of NHR. METHODS: Retrospective evaluation of a series of patients with NHR at our tertiary center between 2012 and 2021 using demographic, clinical, ophthalmologic, virological, therapeutic, and prognostic characteristics was performed. Patients were classified by NHR type: acute retinal necrosis (ARN), progressive outer retinal necrosis (PORN), cytomegalovirus (CMV) retinitis. RESULTS: Forty-one patients with NHR were included: 59% with ARN, 7% with PORN, and 34% with CMV retinitis. All patients with CMV retinitis and PORN were immunocompromised versus 21% of patients with ARN. CMV infection was found in 14 (34%) patients, varicella zoster virus infection in 14 (34%) patients, herpes simplex virus type 2 infection in 8 (20%) and type 1 infection in 5 (12%) patients. Intravenous antiviral therapy was received by 98% of patients and intravitreal antiviral injections by 90% of patients. The overall complication rate during follow-up was 83% of eyes. Most frequent complications were retinal detachment (33% eyes) and retinal break (29% eyes). Prognostic factors for poor visual outcomes were pre-existing monocular vision loss in contralateral eye among 17% of patients, bilateral NHR in 17% of patients, posterior pole involvement in 46% of eyes, and involvement > 2 retinal quadrants in 46% of eyes. CONCLUSIONS: The visual prognosis of patients with NHR remains poor. Prompt investigation of immune status and presence of factors justifying intravitreal antiviral injections must be prioritized to initiate and adapt management while awaiting causative virus confirmation.


Asunto(s)
Retinitis por Citomegalovirus , Infecciones Virales del Ojo , Síndrome de Necrosis Retiniana Aguda , Humanos , Pronóstico , Estudios Retrospectivos , Antivirales/uso terapéutico , Síndrome de Necrosis Retiniana Aguda/diagnóstico , Síndrome de Necrosis Retiniana Aguda/tratamiento farmacológico , Retinitis por Citomegalovirus/tratamiento farmacológico , Infecciones Virales del Ojo/diagnóstico , Infecciones Virales del Ojo/tratamiento farmacológico
5.
AIDS ; 36(13): 1819-1827, 2022 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-35848585

RESUMEN

OBJECTIVE: Post kala-azar dermal leishmaniasis (PKDL) is a rare complication of visceral leishmaniasis. We aimed at reporting PKDL cases in people living with HIV (PLHIV) and compare their characteristics based on whether PKDL occurred in the context of immune recovery under antiretroviral therapy (ART) or not. DESIGN: National survey and literature review. METHODS: We called for observations in France in October 2020 and performed a literature review from PubMed (Medline) and Web of Science up to December 2020. Two groups of patients were defined based on whether PKDL occurred in the context of immune recovery under ART (group 1) or not (group 2), and compared. RESULTS: Three PLHIV with PKDL identified in France in the last decade were described and added to 33 cases from the literature. Compared with group 2 (16/36, 44.4%), patients from group 1 (20/36, 55.6%) originated more frequently from Europe (12/20, 60% vs. 2/16, 12.5%; P  = 0.0038), had higher median blood CD4 + cell counts (221/µl vs. 61/µl; P  = 0.0005) and increase under ART (122/µl, interquartile range 73-243 vs. 33/µl, interquartile range 0-53; P  = 0.0044), had less frequently concomitant visceral leishmaniasis (3/20, 15% vs. 8/12, 66.7%; P  = 0.006), and a trend to more frequent ocular involvement (7/20, 35% vs. 1/16, 6.25%; P  = 0.0531). CONCLUSION: In PLHIV, PKDL occurs after a cured episode of visceral leishmaniasis as part of an immune restoration disease under ART, or concomitant to a visceral leishmaniasis relapse in a context of AIDS. For the latter, the denomination 'disseminated cutaneous lesions associated with visceral leishmaniasis' seems more accurate than PKDL.


Asunto(s)
Infecciones por VIH , Leishmaniasis Cutánea , Leishmaniasis Visceral , Europa (Continente) , Infecciones por VIH/complicaciones , Infecciones por VIH/tratamiento farmacológico , Humanos , Leishmaniasis Cutánea/complicaciones , Leishmaniasis Cutánea/patología , Leishmaniasis Visceral/complicaciones , Leishmaniasis Visceral/epidemiología , Recurrencia
6.
Genes (Basel) ; 13(7)2022 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-35885985

RESUMEN

Dominant Optic Atrophy (DOA) is one of the most common inherited mitochondrial diseases, leading to blindness. It is caused by the chronic degeneration of the retinal ganglion cells (RGCs) and their axons forming the optic nerve. Until now, DOA has been mainly associated with genes encoding proteins involved in mitochondrial network dynamics. Using next-generation and exome sequencing, we identified for the first time heterozygous PMPCA variants having a causative role in the pathology of late-onset primary DOA in five patients. PMPCA encodes an α subunit of the mitochondrial peptidase (MPP), responsible for the cleavage and maturation of the mitochondrial precursor proteins imported from the cytoplasm into mitochondria. Recently, PMPCA has been identified as the gene responsible for Autosomal Recessive Cerebellar Ataxia type 2 (SCAR2) and another severe recessive mitochondrial disease. In this study, four PMPCA variants were identified, two are frameshifts (c.309delA and c.820delG) classified as pathogenic and two are missenses (c.1363G>A and c.1547G>A) classified with uncertain pathological significance. Functional assays on patients' fibroblasts show a hyperconnection of the mitochondrial network and revealed that frameshift variants reduced α-MPP levels, while not significantly affecting the respiratory machinery. These results suggest that alterations in mitochondrial peptidase function can affect the fusion-fission balance, a key element in maintaining the physiology of retinal ganglion cells, and consequently lead to their progressive degeneration.


Asunto(s)
Enfermedades Mitocondriales , Atrofia Óptica Autosómica Dominante , Humanos , Secuenciación de Nucleótidos de Alto Rendimiento , Proteínas Mitocondriales/genética , Atrofia Óptica Autosómica Dominante/genética , Atrofia Óptica Autosómica Dominante/metabolismo , Atrofia Óptica Autosómica Dominante/patología , Péptido Hidrolasas , Peptidasa de Procesamiento Mitocondrial
7.
Front Neurol ; 13: 880312, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35463141

RESUMEN

Erdheim-Chester disease (ECD) is a rare histiocytic disorder, recently recognized to be neoplastic. The clinical phenotype of the disease is extremely heterogeneous, and depends on the affected organs, with the most frequently reported manifestations being bone pain, diabetes insipidus and neurological disorders including ataxia. In this article, we report on a case of a 48-year-old woman, whose initial symptom of gait instability was isolated. This was associated with positional nystagmus with central features: nystagmus occurring without latency, clinically present with only mild symptoms, and resistant to repositioning maneuvers. The cerebral MRI showed bilateral intra-orbital retro-ocular mass lesions surrounding the optic nerves and T2 hyperintensities in the pons and middle cerebellar peduncles. A subsequent CT scan of the chest abdomen and pelvis found a left "hairy kidney", while 18 F-FDG PET-CT imaging disclosed symmetric 18F-FDG avidity predominant at the diametaphyseal half of both femurs. Percutaneous US-guided biopsy of perinephric infiltrates and the kidney showed infiltration by CD68(+), CD1a(-), Langerin(-), PS100(-) foamy histiocytes with BRAF V600E mutation. The combination of the different radiological abnormalities and the result of the biopsy confirmed the diagnosis of ECD. Many clinical and radiological descriptions are available in the literature, but few authors describe vestibulo-ocular abnormalities in patients with ECD. Here, we report on a case of ECD and provide a precise description of the instability related to central positional nystagmus, which led to the diagnosis of ECD.

8.
Ophthalmic Res ; 65(5): 546-555, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35477162

RESUMEN

INTRODUCTION: We performed a prospective, single-center, cohort study in order to evaluate the effects of vitrectomy with epiretinal membrane (ERM) peel on optical quality in patients with primary ERM. METHODS: Thirty patients treated for primary ERM by vitrectomy with ERM peel were included from our tertiary university hospital ophthalmology department. The main study outcome was a variation in optical quality parameters measured using the HD Analyzer™ between preoperative and 2-month postoperative evaluations in operated eyes. Optical quality parameters comprised point spread function (PSF) width at 10% and 50%, objective scatter index (OSI), and modulation transfer function (MTF) cutoff. Contralateral non-operated eyes were used as an internal control for measurement reproducibility. RESULTS: Mean PSF width at 10% (42.22 vs. 27.37 arc/min; p = 0.0002) and mean OSI (3.32 vs. 2.32; p = 0.0003) were significantly improved between pre- versus postoperative evaluations. Mean PSF width at 50% and mean MTF cutoff showed no changes. Subgroup analysis according to crystalline lens status gave similar results, demonstrating that improvements in mean PSF width at 10% and OSI were not lens-related. Non-operated eyes showed no changes in any of the parameters analyzed. CONCLUSION: Reduced light scattering measured by OSI indicates improved optical quality following vitrectomy with ERM peel among patients with primary ERM. OSI measurement could thus be a new parameter of interest in the preoperative assessment of primary ERM and other pre-vitrectomy assessments.


Asunto(s)
Membrana Epirretinal , Aberrometría/métodos , Estudios de Cohortes , Membrana Epirretinal/diagnóstico , Membrana Epirretinal/etiología , Membrana Epirretinal/cirugía , Humanos , Estudios Prospectivos , Reproducibilidad de los Resultados , Estudios Retrospectivos , Tomografía de Coherencia Óptica/métodos , Agudeza Visual , Vitrectomía/métodos
9.
Mult Scler ; 28(2): 189-197, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33988466

RESUMEN

BACKGROUND: Leptomeningeal enhancement (LME) is a key feature of Susac syndrome (SuS) but is only occasionally depicted on post-contrast T1-weighted images (T1-WI). OBJECTIVE: As post-contrast fluid-attenuated inversion recovery (FLAIR) may be more sensitive, our aim was to assess LME in SuS on this sequence. METHODS: From 2010 to 2020, 20 patients with definite SuS diagnosis were retrospectively enrolled in this multicentre study. Two radiologists independently assessed the number of LME on post-contrast FLAIR and T1-WI acquisitions performed before any treatment. A chi-square test was used to compare both sequences and the interrater agreement was calculated. RESULTS: Thirty-five magnetic resonance imagings (MRIs) were performed before treatment, including 19 post-contrast FLAIR images in 17 patients and 25 post-contrast T1-WI in 19 patients. In terms of patients, LME was observed on all post-contrast FLAIR, contrary to post-contrast T1-WI (17/17 (100%) vs. 15/19 (79%), p < 0.05). In terms of sequences, LME was observed on all post-contrast FLAIR, contrary to post-contrast T1-WI (19/19 (100%) vs. 16/25 (64%), p < 0.005). LME was disseminated at both supratentorial (19/19) and infratentorial (18/19) levels on post-contrast FLAIR, contrary to post-contrast T1-WI (3/25 and 9/25, respectively). Interrater agreement was excellent for post-contrast FLAIR (κ = 0.95) but only moderate for post-contrast T1-WI (κ = 0.61). CONCLUSION: LME was always observed and easily visible on post-contrast FLAIR images prior to SuS treatment. In association with other MRI features, it is highly indicative of SuS.


Asunto(s)
Síndrome de Susac , Medios de Contraste , Diagnóstico Precoz , Humanos , Imagen por Resonancia Magnética/métodos , Estudios Retrospectivos , Síndrome de Susac/diagnóstico por imagen
10.
Anal Bioanal Chem ; 414(1): 451-463, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33751162

RESUMEN

Oxazepam, one of the most frequently prescribed anxiolytic drugs, is not completely removed from wastewater with conventional treatment processes. It can thus be found at trace levels in environmental water, with human urine constituting the major source of contamination. This study focused on the development and characterization of molecularly imprinted polymers (MIPs) for the selective solid-phase extraction of oxazepam at trace levels from environmental water and human urine samples. Two MIPs were synthesized, and their selectivity in pure organic and aqueous media were assayed. After optimizing the extraction procedure adapted to a large sample volume to reach a high enrichment factor, the most promising MIP was applied to the selective extraction of oxazepam from environmental water. Extraction recoveries of 83 ± 12, 92 ± 4 and 89 ± 10% were obtained using the MIP for tap, mineral and river water, respectively, while a recovery close to 40% was obtained on the corresponding non-imprinted polymer (NIP). Thanks to the high enrichment factors, a limit of quantification (LOQ) of 4.5 ng L-1 was obtained for river water. A selective extraction procedure was also developed for urine samples and gave rise to extraction recoveries close to 95% for the MIP and only 23% for the NIP. Using the MIP, a LOQ of 357 ng L-1 was obtained for oxazepam in urine. The use of the MIP also helped to limit the matrix effects encountered for the quantification of oxazepam in environmental samples and in human urine samples after extraction on an Oasis HLB sorbent.


Asunto(s)
Impresión Molecular , Cromatografía Líquida de Alta Presión , Humanos , Impresión Molecular/métodos , Polímeros Impresos Molecularmente , Oxazepam , Polímeros , Extracción en Fase Sólida/métodos
11.
Front Physiol ; 12: 692361, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34335300

RESUMEN

Neuro-ophthalmological changes named spaceflight associated neuro-ocular syndrome (SANS) reported after spaceflights are important medical issues. Dry immersion (DI), an analog to microgravity, rapidly induces a centralization of body fluids, immobilization, and hypokinesia similar to that observed during spaceflight. The main objectives of the present study were 2-fold: (1) to assess the neuro-ophthalmological impact during 5 days of DI and (2) to determine the effects of venoconstrictive thigh cuffs (VTC), used as a countermeasure to limit headward fluid shift, on DI-induced ophthalmological adaptations. Eighteen healthy male subjects underwent 5 days of DI with or without VTC countermeasures. The subjects were randomly assigned into two groups of 9: a control and cuffs group. Retinal and optic nerve thickness were assessed with spectral-domain optical coherence tomography (OCT). Optic nerve sheath diameter (ONSD) was measured by ocular ultrasonography and used to assess indirect changes in intracranial pressure (ICP). Intraocular pressure (IOP) was assessed by applanation tonometry. A higher thickness of the retinal nerve fiber layer (RNFL) in the temporal quadrant was observed after DI. ONSD increased significantly during DI and remained higher during the recovery phase. IOP did not significantly change during and after DI. VTC tended to limit the ONSD enlargement but not the higher thickness of an RNFL induced by DI. These findings suggest that 5 days of DI induced significant ophthalmological changes. VTC were found to dampen the ONSD enlargement induced by DI.

12.
Sci Rep ; 11(1): 10031, 2021 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-33976247

RESUMEN

Heads-up three-dimensional (3D) surgical visualization systems allow ophthalmic surgeons to replace surgical microscope eyepieces with high-resolution stereoscopic cameras transmitting an image to a screen. We investigated the effectiveness and safety of the heads-up NGENUITY 3D Visualization System in a retrospective evaluation of 241 consecutive vitreoretinal surgeries performed by the same surgeon using conventional microscopy (CM group) over a 1-year period versus the NGENUITY System (3D group) over a consecutive 1-year period. We included for study vitreoretinal surgeries for treatment of retinal detachment (RD) (98 surgeries), macular hole (MH) (48 surgeries), or epiretinal membrane (ERM) (95 surgeries). A total of 138 and 103 eyes were divided into 3D and CM groups, respectively. We found no differences in 3-month postoperative rates of recurrence of RD (10% versus 18%, p = 0.42), MH closure (82% versus 88%, p = 0.69), or decrease in central macular thickness of ERMs (134 ± 188 µm versus 115 ± 105 µm, p = 0.57) between the 3D and CM groups, respectively. Surgery durations and visual prognosis were also similar between both groups. We consolidate that the NGENUITY System is comparable in terms of visual and anatomical outcomes, giving it perspectives for integration into future robotized intervention.


Asunto(s)
Cirugía Vitreorretiniana/instrumentación , Anciano , Femenino , Francia , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Centros de Atención Terciaria/estadística & datos numéricos , Cirugía Vitreorretiniana/estadística & datos numéricos
14.
Analyst ; 143(5): 1077-1086, 2018 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-29383369

RESUMEN

A microfluidic microreactor for trypsin mediated transthyretin (TTR) digestion has been developed as a step towards the elaboration of a fully integrated microdevice for the detection of a rare and disabling disease, the familial transthyretin amyloidosis (ATTR) which is related to specific TTR mutations. Therefore, an enzymatic microreactor coupled to an analytical step able to monitor the mutation of TTR on specific peptide fragments would allow an accurate monitoring of the treatment efficiency of ATTR. In this study, two types of immobilized trypsin microreactors have been investigated: a new miniaturized, microfluidic fluidized bed packed with trypsin functionalized magnetic particles (MPs), and a thiol-ene (TE) monolith-based chip. Their performances were first demonstrated with N-benzoyl-dl-arginine-4-nitroanilide hydrochloride BApNA, a low molecular weight substrate. High reaction yields (75.2%) have been reached within 0.6 min for the TE-based trypsin microreactor, while a lower yield (12.4%) was obtained for the micro-fluidized bed within a similar residence time. Transposition of the optimized conditions, developed with BApNA, to TTR digestion in the TE-based trypsin microreactor was successfully performed. We demonstrated that the TE-chip can achieve an efficient and reproducible digestion of TTR. This has been assessed by MS detection. In addition, TTR hydrolysis led to the production of a fragment of interest allowing the therapeutic follow-up of more than twenty possible ATTR mutations. High sequence coverage (90%), similar to those obtained with free trypsin, was achieved in a short time (2.4 min). Repeated experiments showed good reproducibility (RSD = 6.8%). These promising results open up the route for an innovative treatment follow-up dedicated to ATTR.


Asunto(s)
Neuropatías Amiloides Familiares/diagnóstico , Técnicas Analíticas Microfluídicas/instrumentación , Prealbúmina/análisis , Humanos , Reproducibilidad de los Resultados
15.
Chemphyschem ; 18(19): 2799-2806, 2017 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-28419652

RESUMEN

The reactivity of ethylene carbonate (EC) and of a EC/diethyl carbonate (DEC) mixture was studied under ionizing radiation to mimic the aging phenomena that occur in lithium-ion batteries. Picosecond-pulse radiolysis experiments showed that the attachment of the electron to the EC molecule is ultrafast (k(e-EC +EC)=1.3×109  L mol-1 s-1 at 46 °C). This reaction rate is accelerated by a factor of 5.7 compared with the electron attachment to propylene carbonate, which implies that the presence of the methyl group significantly slows the reaction. In a 50:50 EC/DEC mixture, just after the electron pulse the electron is solvated by a mixture of EC and DEC molecules, but its fast decay is attributed exclusively to electron attachment to the EC molecule. Stable products detected after steady-state irradiation were mainly H2 , CH4 , CO, and CO2 . The evolution of the radiolytic yields with the EC fraction shows that H2 and CH4 did not exhibit linear behavior, whereas CO and CO2 did. Indeed, H2 and CH4 mainly arise from the excited state of DEC, the formation of which is significantly affected by the evolution of the dielectric constant of the mixture and by the electron attachment to EC. CO formation is mainly due to the reactivity of the EC molecule, which is not affected in the mixture, as proven by pulse-radiolysis experiments.

16.
Electrophoresis ; 37(17-18): 2401-9, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27387591

RESUMEN

Crossed immunoelectrophoresis (C-IE) is used to detect and quantify specific proteins. An application allowed the evaluation of complement system activation by nanomaterials. The work aimed to improve the C-IE toward a higher throughput and less tedious method. A new concept was implemented to prepare and run agarose gels. The first and the second dimension of electrophoresis were performed on a single gel plate, prepared before the beginning of the analysis. Several samples were migrated simultaneously on the same migration line. Up to 35 analyses were run at once, providing stamp-sized electrophoregrams (2.8 × 3 cm(2) ) maintaining the performance of the original method performed on 5 × 7 cm(2) gel slabs. Robustness and precision of the method were demonstrated through a validation approach using ANOVA. Handling, experimental duration, amount of reagents, and overall cost of one analysis were considerably reduced compared to the original method. With the same equipment, seven times more analyses can be performed in one run. C-IE can be used to analyze many types of proteins. The new experimental modalities were suitable for the application developed in the present work that was to evaluate activation of protein C3 of the complement system triggered by nanomaterials.


Asunto(s)
Complemento C3/análisis , Inmunoelectroforesis/métodos , Análisis de Varianza , Reproducibilidad de los Resultados
17.
Pharm Res ; 33(5): 1220-34, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26864858

RESUMEN

PURPOSE: Evaluation of particle size distribution (PSD) of multimodal dispersion of nanoparticles is a difficult task due to inherent limitations of size measurement methods. The present work reports the evaluation of PSD of a dispersion of poly(isobutylcyanoacrylate) nanoparticles decorated with dextran known as multimodal and developed as nanomedecine. METHODS: The nine methods used were classified as batch particle i.e. Static Light Scattering (SLS) and Dynamic Light Scattering (DLS), single particle i.e. Electron Microscopy (EM), Atomic Force Microscopy (AFM), Tunable Resistive Pulse Sensing (TRPS) and Nanoparticle Tracking Analysis (NTA) and separative particle i.e. Asymmetrical Flow Field-Flow Fractionation coupled with DLS (AsFlFFF) size measurement methods. RESULTS: The multimodal dispersion was identified using AFM, TRPS and NTA and results were consistent with those provided with the method based on a separation step prior to on-line size measurements. None of the light scattering batch methods could reveal the complexity of the PSD of the dispersion. CONCLUSIONS: Difference between PSD obtained from all size measurement methods tested suggested that study of the PSD of multimodal dispersion required to analyze samples by at least one of the single size particle measurement method or a method that uses a separation step prior PSD measurement.


Asunto(s)
Nanopartículas/química , Nanopartículas/ultraestructura , Dispersión Dinámica de Luz , Fraccionamiento de Campo-Flujo , Microscopía de Fuerza Atómica , Microscopía Electrónica , Tamaño de la Partícula
18.
J Chromatogr A ; 1229: 280-7, 2012 Mar 16.
Artículo en Inglés | MEDLINE | ID: mdl-22333681

RESUMEN

A screening strategy based on hyphenated capillary electrophoresis and inductively coupled plasma mass spectrometry (CE-ICP-MS) was developed to classify phosphorylated ligands according to their europium(III) binding affinity in a hydro-organic medium (sodium formate, pH 3.7, H(2)O/MeOH 90:10, v/v). Taking advantage of the high sensibility of ICP-MS for detecting phosphorus, this method enabled to assess the affinity of a variety of phosphorylated compounds, including phosphine oxides, thiophosphines, phosphonates, and phosphinates, in less than 1h and using less than 5 ng of substance. By varying the total europium concentration, complexation constants could be determined according to a sequential multiple run strategy, which proved to be in excellent agreement with the values obtained by UV-Vis absorption spectrophotometric titrations.


Asunto(s)
Electroforesis Capilar/métodos , Europio/química , Elementos de la Serie de los Lantanoides/química , Espectrometría de Masas/métodos , Compuestos de Fósforo/química , Formiatos , Ligandos , Límite de Detección , Modelos Lineales , Metanol , Análisis de Componente Principal , Reproducibilidad de los Resultados , Espectrofotometría Ultravioleta , Termodinámica
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