Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 310
Filtrar
1.
Anal Chim Acta ; 1304: 342470, 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38637058

RESUMEN

BACKGROUND: Iridium(III) complexes, exhibiting high luminescence quantum yields and a wide range of emission colours, are promising alternatives to tris(2,2'-bipyridine)ruthenium(II) for chemiluminescence (CL) and electrochemiluminescence (ECL) detection. This emerging class of reagent, however, is limited by the poor solubility of many iridium(III) complexes in aqueous solution, and lack of understanding of their remarkably variable selectivities towards different analytes. RESULTS: Seven [Ir(C^N)2(pt-TEG)]+ complexes, exhibiting a wide range of reduction potentials and emission energies, were examined with six model analytes. For CL, cerium(IV) was used as the oxidant. The alkylamine analytes generally produced greater CL and ECL with the more readily oxidised Ir(III) complexes (C^N = piq, bt, ppy), predominantly through the 'direct' pathway requiring oxidation of both metal complex and analyte. Aniline derivatives that did not also contain secondary or tertiary alkylamines elicited CL from the less readily oxidised complexes (C^N = df-ppy-CF3, df-ppy) via energy transfer. The most difficult to oxidise complexes (C^N = df(CF3)-ppy-Me, df(CN)-ppy) gave poor responses due to the limited potential window of the solvent and inefficiency of energy transfer to their high energy excited states. Greater CL and/or ECL intensities were generally obtained for each analyte with at least one Ir(III) complex than with [Ru(bpy)3]2+; superior limits of detection for two analytes were demonstrated. SIGNIFICANCE: This exploration of CL/ECL in which the properties of luminophore, analyte and oxidant are all varied provides a new understanding of the influence of the metal-complex potentials and excited state energy on the light-producing and quenching pathways, and consequently, their distinct selectivity towards different analytes. These findings will guide the development of water-soluble Ir(III) complexes as CL and ECL reagents.

2.
Angew Chem Int Ed Engl ; : e202319047, 2024 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-38519420

RESUMEN

We report the electrochemiluminescence (ECL) of a 3d6 Cr(0) complex ([Cr(LMes)3]; λem=735 nm) with comparable photophysical properties to those of ECL-active complexes of 4d6 or 5d6 precious metal ions. The electrochemical potentials of [Cr(LMes)3] are more negative than those of [Ir(ppy)3] and render the [Cr(LMes)3]* excited state inaccessible through conventional co-reactant ECL with tri-n-propylamine or oxalate. ECL can be obtained, however, through the annihilation route in which potentials sufficient to oxidise and reduce the luminophore are alternately applied. When combined with [Ir(ppy)3] (λem=520 nm), the annihilation ECL of [Cr(LMes)3] was greatly enhanced whereas that of [Ir(ppy)3] was diminished. Under appropriate conditions, the relative intensities of the two spectrally distinct emissions can be controlled through the applied potentials. From this starting point for ECL with 3d6 metal complexes, we discuss some directions for future development.

3.
Chem Sci ; 15(3): 1150-1158, 2024 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-38239687

RESUMEN

Electrochemiluminescence (ECL) is a highly sensitive mode of detection utilised in commercialised bead-based immunoassays. Recently, the introduction of a freely diffusing water-soluble Ir(iii) complex was demonstrated to enhance the ECL emission of [Ru(bpy)3]2+ labels anchored to microbeads, but a comprehensive investigation of the proposed 'redox-mediated' mechanism was not carried out. In this work, we select three different water-soluble Ir(iii) complexes by virtue of their photophysical and electrochemical properties in comparison with those of the [Ru(bpy)3]2+ luminophore and the TPrA co-reactant. A systematic investigation of the influence of each Ir(iii) complex on the emission of the Ru(ii) labels on single beads by ECL microscopy revealed that the heterogeneous ECL can be finely tuned and either enhanced up to 107% or lowered by 75%. The variation of the [Ru(bpy)3]2+ ECL emission was correlated to the properties of each Ir(iii)-based mediator, which enabled us to decipher the mechanism of interaction and define guidelines for the future design of novel Ir(iii) complexes to further enhance the ECL emission of bead-based immunoassays. Ultimately, we showcase the potential of this technology for practical sample analysis in commercial instruments by assessing the enhancement of the collective ECL intensity from a bead-based system.

4.
Cornea ; 43(4): 528-530, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38166243

RESUMEN

PURPOSE: Immune checkpoint inhibitors (ICIs) have been recently introduced for the treatment of locally unresectable conjunctival squamous cell carcinoma. We present 2 cases with conjunctival intraepithelial neoplasia (CIN) who were treated with ICIs. METHODS: A report of 2 cases with CIN who were treated with systemic cemiplimab (350 mg IV every 3 weeks). RESULTS: A 70-year-old man was treated with cemiplimab for metastatic cutaneous squamous cell carcinoma. The pre-existing CIN continued to progress over the nasal bulbar conjunctiva and cornea, while the other metastatic sites, including parotid glands, and neck lymph nodes showed a complete response after 16 cycles of treatment. An 84-year-old woman had bilateral diffuse CIN involving bulbar and lower eyelid palpebral conjunctiva. Cemiplimab was started because of the extent of involvement. While the bulk of CIN was reduced, it progressed over the cornea and forniceal conjunctiva on OU after 10 cycles of treatment. Excisional biopsies of conjunctival lesions after cemiplimab confirmed CIN in both patients. CONCLUSIONS: Although conjunctival squamous cell carcinoma tumors are reported to be highly responsive to ICIs, a similar effect has not been observed in 2 patients with CIN. Further studies are needed to evaluate ICIs in the management of CIN.


Asunto(s)
Anticuerpos Monoclonales Humanizados , Carcinoma in Situ , Carcinoma de Células Escamosas , Neoplasias de la Conjuntiva , Neoplasias Cutáneas , Masculino , Femenino , Humanos , Anciano de 80 o más Años , Lactante , Carcinoma de Células Escamosas/patología , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Neoplasias Cutáneas/tratamiento farmacológico , Carcinoma in Situ/patología , Neoplasias de la Conjuntiva/patología
5.
Ophthalmic Plast Reconstr Surg ; 40(1): 18-29, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38241616

RESUMEN

PURPOSE: To review the outcomes of targeted therapy and immunotherapy in advanced conjunctival tumors, including conjunctival squamous cell carcinoma, conjunctival melanoma, and conjunctival lymphoma. METHODS: A Pubmed database systematic search was performed between January 1999 and December 2022. The literature search was limited to studies published in English. RESULTS: This review included 142 patients with advanced malignant conjunctival tumors from 42 articles. In the conjunctival squamous cell carcinoma group, 2 cases of advanced conjunctival squamous cell carcinoma treated with epidermal growth factor receptor inhibitors showed significant tumor size improvement after 7.5 months of follow-up. Among 7 cases treated with systemic immunotherapy, 5 cases (72%) had complete response (CR), 1 case (14%) showed partial response (PR), and 1 case (14%) had stable disease (SD) after 16 months. In the conjunctival melanoma group, among 18 cases treated with combined v-raf murine sarcoma viral oncogene homolog B1/mitogen-activated extracellular signal-regulated kinase inhibitors, 6 (33%) had CR, 5 (28%) had PR, 2 (11%) had SD, and 5 (28%) had progressive disease after 24.8 months of follow-up. Of 44 conjunctival melanoma cases treated with immunotherapy, 12 (28%) had CR, 9 (20%) had PR, 7(16%) had SD, and 16 (36%) had progressive disease after 14.2 months. Systemic Rituximab treatment for conjunctival lymphoma cases resulted in CR in 21 patients (63%), PR in 11 patients (33%), and SD in 1 patient (3%) after 20.5 months of follow-up. Intralesional Rituximab injections in 38 conjunctival lymphoma cases showed CR in 28 patients (75%), PR in 7 patients (19%), SD in 1 patient (2%), and progressive disease in 2 patients (4%) after 20.4 months of follow-up. CONCLUSIONS: Despite limited clinical case reports and short-term follow-ups, targeted therapy and immunotherapy have shown promising results for advanced malignant conjunctival tumors.


Asunto(s)
Carcinoma de Células Escamosas , Neoplasias de la Conjuntiva , Linfoma , Melanoma , Neoplasias Cutáneas , Animales , Humanos , Ratones , Carcinoma de Células Escamosas/patología , Neoplasias de la Conjuntiva/terapia , Inmunoterapia , Linfoma/patología , Melanoma/tratamiento farmacológico , Rituximab/uso terapéutico
6.
Artículo en Inglés | MEDLINE | ID: mdl-37552493

RESUMEN

PURPOSE: Periocular locally advanced basal cell carcinoma (POLA-BCC) is characterized by orbital involvement and/or extensive invasion of periocular structures. Hedgehog pathway inhibitors have been used for POLA-BCC with promising outcomes. METHODS: The authors reviewed 11 articles published in English literature from January 2012 to July 2022 and reported the outcomes of patients with POLA-BCC who were treated with vismodegib. RESULTS: A total of 384 patients were treated with vismodegib. The mean age was 72 years, and the median treatment duration was 9 months. The overall response rate was 75% with a median follow-up time of 14.4 months. Following vismodegib treatment, the median number of patients who required adjuvant surgery was 43% with a median time to surgery of 6.5 months. The exenteration rate was 6% (overall 8 patients). In total 93.7% of patients experienced grade I adverse events, 26.7% to 37.5% grade II, 8.8% to 10% grade III-IV, and 0.8% to 4.8% grade V. Major side effects included dysgeusia (30-100%), muscle spasm (15-100%), alopecia (47-75%), weight loss (23-83%), and decreased appetite (19-42%). The median percentage of patients who discontinued treatment due to toxicity was 29% with a median interval of 5 months before the development of side effects. The median recurrence rate following discontinuation of vismodegib was 7.8% with a median recurrence duration of 20 months. CONCLUSIONS: In patients with POLA-BCC, vismodegib, a hedgehog pathway inhibitor, provided high rates of orbital preservation, reducing exenteration rates to 6%. Neoadjuvant therapy with vismodegib can also be suggested for patients with POLA-BCC. While extremely effective, side effects lead to temporary or permanent discontinuation of vismodegib in small numbers of patients.


Asunto(s)
Antineoplásicos , Carcinoma Basocelular , Piridinas , Neoplasias Cutáneas , Humanos , Anciano , Proteínas Hedgehog/uso terapéutico , Resultado del Tratamiento , Carcinoma Basocelular/patología , Anilidas/uso terapéutico , Antineoplásicos/efectos adversos , Neoplasias Cutáneas/tratamiento farmacológico , Neoplasias Cutáneas/patología
7.
Health Technol Assess ; 27(23): 1-108, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37929672

RESUMEN

Background: Agitation is common and impacts negatively on people with dementia and carers. Non-drug patient-centred care is first-line treatment, but we need other treatment when this fails. Current evidence is sparse on safer and effective alternatives to antipsychotics. Objectives: To assess clinical and cost-effectiveness and safety of mirtazapine and carbamazepine in treating agitation in dementia. Design: Pragmatic, phase III, multicentre, double-blind, superiority, randomised, placebo-controlled trial of the clinical effectiveness of mirtazapine over 12 weeks (carbamazepine arm discontinued). Setting: Twenty-six UK secondary care centres. Participants: Eligibility: probable or possible Alzheimer's disease, agitation unresponsive to non-drug treatment, Cohen-Mansfield Agitation Inventory score ≥ 45. Interventions: Mirtazapine (target 45 mg), carbamazepine (target 300 mg) and placebo. Outcome measures: Primary: Cohen-Mansfield Agitation Inventory score 12 weeks post randomisation. Main economic outcome evaluation: incremental cost per six-point difference in Cohen-Mansfield Agitation Inventory score at 12 weeks, from health and social care system perspective. Data from participants and informants at baseline, 6 and 12 weeks. Long-term follow-up Cohen-Mansfield Agitation Inventory data collected by telephone from informants at 6 and 12 months. Randomisation and blinding: Participants allocated 1 : 1 : 1 ratio (to discontinuation of the carbamazepine arm, 1 : 1 thereafter) to receive placebo or carbamazepine or mirtazapine, with treatment as usual. Random allocation was block stratified by centre and residence type with random block lengths of three or six (after discontinuation of carbamazepine, two or four). Double-blind, with drug and placebo identically encapsulated. Referring clinicians, participants, trial management team and research workers who did assessments were masked to group allocation. Results: Two hundred and forty-four participants recruited and randomised (102 mirtazapine, 102 placebo, 40 carbamazepine). The carbamazepine arm was discontinued due to slow overall recruitment; carbamazepine/placebo analyses are therefore statistically underpowered and not detailed in the abstract. Mean difference placebo-mirtazapine (-1.74, 95% confidence interval -7.17 to 3.69; p = 0.53). Harms: The number of controls with adverse events (65/102, 64%) was similar to the mirtazapine group (67/102, 66%). However, there were more deaths in the mirtazapine group (n = 7) by week 16 than in the control group (n = 1). Post hoc analysis suggests this was of marginal statistical significance (p = 0.065); this difference did not persist at 6- and 12-month assessments. At 12 weeks, the costs of unpaid care by the dyadic carer were significantly higher in the mirtazapine than placebo group [difference: £1120 (95% confidence interval £56 to £2184)]. In the cost-effectiveness analyses, mean raw and adjusted outcome scores and costs of the complete cases samples showed no differences between groups. Limitations: Our study has four important potential limitations: (1) we dropped the proposed carbamazepine group; (2) the trial was not powered to investigate a mortality difference between the groups; (3) recruitment beyond February 2020, was constrained by the COVID-19 pandemic; and (4) generalisability is limited by recruitment of participants from old-age psychiatry services and care homes. Conclusions: The data suggest mirtazapine is not clinically or cost-effective (compared to placebo) for agitation in dementia. There is little reason to recommend mirtazapine for people with dementia with agitation. Future work: Effective and cost-effective management strategies for agitation in dementia are needed where non-pharmacological approaches are unsuccessful. Study registration: This trial is registered as ISRCTN17411897/NCT03031184. Funding: This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 27, No. 23. See the NIHR Journals Library website for further project information.


It is common for people with Alzheimer's disease to experience agitation, for example feeling restless or unsettled. If left untreated, agitation can lead to poorer quality of life and increased hospitalisation and strain for family carers. Often these symptoms are treated with medications that are usually used to manage psychosis (antipsychotic drugs), but such medication has limited effectiveness and can cause serious adverse effects to patients, including risk of increased death. Two medications that are already commonly prescribed for other health issues, mirtazapine (an antidepressant) and carbamazepine (a drug used to treat epilepsy), had been identified as a possible alternative way of treating agitation in Alzheimer's disease that might not have the harms associated with antipsychotic medication. In this study, we compared the effects of giving mirtazapine or carbamazepine with a dummy drug (placebo) in people with Alzheimer's disease who were experiencing agitation. The results of the study showed that neither medication was any more effective than the placebo in reducing agitation over 12 weeks in terms of improving symptoms, or in economic terms. Mirtazapine may lead to additional carer costs as compared to placebo. The study findings are stronger for mirtazapine than carbamazepine because the carbamazepine arm was stopped when it had recruited less than half the numbers needed. That was done because the study was not recruiting quickly enough to support both the mirtazapine and the carbamazepine arms. The findings from this study show that mirtazapine should not be recommended to treat agitation in Alzheimer's disease. More work is needed to formulate effective ways and to test new drug and non-drug treatments for agitation in dementia.


Asunto(s)
Enfermedad de Alzheimer , Humanos , Enfermedad de Alzheimer/tratamiento farmacológico , Carbamazepina/uso terapéutico , Análisis Costo-Beneficio , Mirtazapina/uso terapéutico , Pandemias , Calidad de Vida , Evaluación de la Tecnología Biomédica
8.
Macromol Rapid Commun ; : e2300274, 2023 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-37474483

RESUMEN

Nitroxide groups covalently grafted to carbon fibers are used as anchoring sites for TEMPO-terminated polymers (poly-n-butylacrylate and polystyrene) in a "graft to" surface modification strategy. All surface-modified fibers are evaluated for their physical properties, showing that several treatments have enhanced the tensile strength and Young's modulus compared to the control fibers. Up to an 18% increase in tensile strength and 12% in Young's modulus are observed. Similarly, the evaluation of interfacial shear strength in an epoxy polymer shows improvements of up to 144% relative to the control sample. Interestingly, the polymer-grafted surfaces show smaller increases in interfacial shear strength compared to surfaces modified with a small molecule only. This counterintuitive result is attributed to the incompatibility, both chemical and physical, of the grafted polymers to the surrounding epoxy matrix. Molecular dynamics simulations of the interface suggest that the diminished increase in mechanical shear strength observed for the polymer grafted surfaces may be due to the lack of exposed chain ends, whereas the small molecule grafted interface exclusively presents chain ends to the resin interface, resulting in good improvements in mechanical properties.

9.
Brain Pathol ; 33(6): e13190, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37463072

RESUMEN

Docosahexaenoic acid (DHA) is an essential omega-3 polyunsaturated fatty acid implicated in cognitive functions by promoting synaptic protein expression. While alterations of specific DHA-containing phospholipids have been described in the neocortex of patients with Alzheimer's disease (AD), the status of these lipids in dementia with Lewy bodies (DLB), known to manifest aggregated α-synuclein-containing Lewy bodies together with variable amyloid pathology, is unclear. In this study, post-mortem samples from the parietal cortex of 25 DLB patients and 17 age-matched controls were processed for phospholipidomics analyses using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) platform. After controlling for false discovery rate, six out of the 46 identified putative DHA-phospholipid species were significantly decreased in DLB, with only one showing increase. Altered putative DHA-phospholipid species were subsequently validated with further LC-MS/MS measurements. Of the DHA-containing phospholipid (DCP) species showing decreases, five negatively correlated with soluble beta-amyloid (Aß42) levels, whilst three also correlated with phosphorylated α-synuclein (all p < 0.05). Furthermore, five of these phospholipid species correlated with deficits of presynaptic Rab3A, postsynaptic neurogranin, or both (all p < 0.05). Finally, we found altered immunoreactivities of brain lysolipid DHA transporter, MFSD2A, and the fatty acid binding protein FABP5 in DLB parietal cortex. In summary, we report alterations of specific DCP species in DLB, as well as their associations with markers of neuropathological burden and synaptopathology. These results support the potential role of DHA perturbations in DLB as well as therapeutic targets.


Asunto(s)
Enfermedad de Alzheimer , Enfermedad por Cuerpos de Lewy , Neocórtex , Humanos , alfa-Sinucleína/metabolismo , Enfermedad por Cuerpos de Lewy/patología , Neocórtex/metabolismo , Ácidos Docosahexaenoicos/metabolismo , Cromatografía Liquida , Espectrometría de Masas en Tándem , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/metabolismo , Fosfolípidos/metabolismo , Proteínas de Unión a Ácidos Grasos/metabolismo
10.
J Neuroinflammation ; 20(1): 111, 2023 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-37158957

RESUMEN

BACKGROUND: Chronically dysregulated neuroinflammation has been implicated in neurodegenerative dementias, with separate studies reporting increased brain levels of inflammatory mediators and gliosis in Alzheimer's disease (AD) as well as in Lewy body dementias (LBD). However, it is unclear whether the nature and extent of neuroinflammatory responses in LBD are comparable to those in AD. In this study, we performed head-to-head measurements of a panel of cytokines in the post-mortem neocortex of AD versus the two major clinical subtypes of LBD, namely, dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD). METHODS: Post-mortem tissues from the mid-temporal cortex (Brodmann area 21) of a cohort of neuropathologically well-defined AD, PDD and DLB patients were processed and measured for a comprehensive range of cytokines (IL-1α, IL-1Ra, IL-8, IL-10, IL-12p70, IL-13, IFN-γ, GM-CSF and FGF-2) using a multiplex immunoassay platform. Associations between inflammation markers and neuropathological measures of neuritic plaques, neurofibrillary tangles as well as Lewy bodies were also performed. RESULTS: We found IL-1α, IFN-γ, GM-CSF and IL-13 to be elevated in the mid-temporal cortex of AD patients. In contrast, none of the measured cytokines were significantly altered in either DLB or PDD. Similar cytokine changes were observed in two other neocortical areas of AD patients. Furthermore, increases of IL-1α, IFN-γ, GM-CSF, IL-10 and IL-13 associated with moderate-to-severe neurofibrillary tangle burden, but not with neuritic plaques or Lewy bodies. Our findings of elevated neocortical pro- and anti-inflammatory cytokines in AD, but not in DLB or PDD, suggest that neuroinflammatory responses are strongly linked to neurofibrillary tangle burden, which is higher in AD compared to LBD. In conclusion, neuroinflammation may not play a prominent role in the pathophysiology of late-stage LBD.


Asunto(s)
Enfermedad de Alzheimer , Demencia , Neocórtex , Enfermedad de Parkinson , Humanos , Citocinas , Factor Estimulante de Colonias de Granulocitos y Macrófagos , Interleucina-10 , Interleucina-13 , Enfermedades Neuroinflamatorias , Placa Amiloide
11.
Anal Chem ; 95(18): 7372-7378, 2023 05 09.
Artículo en Inglés | MEDLINE | ID: mdl-37098243

RESUMEN

Electrochemiluminescence (ECL) microscopy is an emerging technique with new applications such as imaging of single entities and cells. Herein, we have developed a bimodal and bicolor approach to record both positive ECL (PECL: light-emitting object on dark background) and shadow label-free ECL (SECL: nonemissive object shadowing the background luminescence) images of single cells. This bimodal approach is the result of the simultaneous emissions of [Ru(bpy)3]2+ used to label the cellular membrane (PECL) and [Ir(sppy)3]3- dissolved in solution (SECL). By spectrally resolving the ECL emission wavelengths, we recorded the images of the same cells in both PECL and SECL modes using the [Ru(bpy)3]2+ (λmax = 620 nm) and [Ir(sppy)3]3- (λmax = 515 nm) luminescence, respectively. PECL shows the distribution of the [Ru(bpy)3]2+ labels attached to the cellular membrane, whereas SECL reflects the local diffusional hindrance of the ECL reagents by each cell. The high sensitivity and surface-confined features of the reported approach are demonstrated by imaging cell-cell contacts during the mitosis process. Furthermore, the comparison of PECL and SECL images demonstrates the differential diffusion of tri-n-propylamine and [Ir(sppy)3]3- through the permeabilized cell membranes. Consequently, this dual approach enables the imaging of the morphology of the cell adhering on the surface and can significantly contribute to multimodal ECL imaging and bioassays with different luminescent systems.


Asunto(s)
Mediciones Luminiscentes , Microscopía , Mediciones Luminiscentes/métodos , Fotometría , Luminiscencia , Membrana Celular
12.
J Org Chem ; 88(10): 6445-6453, 2023 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-36629260

RESUMEN

Sacrificial additives are commonly employed in photoredox catalysis as a convenient source of electrons, but what occurs after electron transfer is often overlooked. Tertiary alkylamines initially form radical cations following electron transfer, which readily deprotonate to form strongly reducing, neutral α-amino radicals. Similarly, the oxalate radical anion (C2O4•-) rapidly decomposes to form CO2•- (E0 ≈ -2.2 V vs SCE). We show that not only are these reactive intermediates formed under photoredox conditions, but they can also impact the desired photochemistry, both positively and negatively. Photoredox systems using oxalate as an electron donor are able to engage substrates with greater energy demands, extending reactivity past the energy limits of single and multiphoton transition metal catalysts. Furthermore, oxalate offers better chemoselectivity than the commonly employed triethylamine when reducing substrates with moderate energy requirements.

13.
ACS Sens ; 8(2): 933-939, 2023 02 24.
Artículo en Inglés | MEDLINE | ID: mdl-36701204

RESUMEN

Heterogeneous electrochemiluminescence (ECL) assays employing tri-n-propylamine as a co-reactant and a tris(2,2'-bipyridine)ruthenium(II) ([Ru(bpy)3]2+) derivative as an emissive label are integral to the majority of academic and commercial applications of ECL sensing. This model system is an active research area and constitutes the basis of successfully commercialized bead-based ECL immunoassays. Herein, we propose a novel approach to the enhancement of such conventional ECL assays via the incorporation of a second metal coordination complex, [Ir(sppy)3]3- (where sppy = 5'-sulfo-2-phenylpyridinato-C2,N), to the experimental system. By employing ECL microscopy, we are able to map the spatial distribution of ECL emission at the surface of the bead, from [Ru(bpy)3]2+ labels, and solution-phase emission, from [Ir(sppy)3]3-. The developed [Ir(sppy)3]3--mediated enhancement approach elicited a significant improvement (70.9-fold at 0.9 V and 2.9-fold at 1.2 V vs Ag/AgCl) of the ECL signal from [Ru(bpy)3]2+ labels immobilized on the surface of a polystyrene bead. This dramatic enhancement in ECL signal, particularly at low oxidation potentials, has important implications for the improvement of existing heterogeneous ECL assays and ECL-based microscopy, by amplifying the signal, opening new bioanalytical detection schemes, and reducing both electrode surface passivation and deleterious side reactions.


Asunto(s)
Complejos de Coordinación , Rutenio , Iridio , Mediciones Luminiscentes , Fotometría
14.
Indian J Public Health ; 66(Supplement): S60-S65, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36412476

RESUMEN

Background: Delay in diagnosis and treatment enhances tuberculosis (TB) transmission and mortality. Understanding causes for delay can help in TB elimination by 2025, the stated goal of India. Objectives: Estimate diagnostic and treatment delay in Ernakulam district of Kerala, identify associated factors, and determine health-seeking behavior and knowledge regarding TB among new pulmonary TB patients. Materials and Methods: Community-based cross-sectional study among the new pulmonary TB patients registered under Revised National TB Control Program. Patients interviewed in-person and data collected using pretested semi-structured questionnaire. Descriptive statistics expressed as frequency, percent, interquartile range, median, and mean. The Chi-square test was used to assess statistical significance (P < 0.05) of association. Backward conditional method logistic regression done using variables with P < 0.2 in univariate analysis and adjusting for possible confounders. Results: Two hundred and twenty-nine patients interviewed and the median patient, health-care system, and treatment delay were 25 days, 22 days, and 1 day, respectively. While the patient delay (>30 days) and treatment delay (>2 days) were seen in 47.6% and 41% of patients, respectively, health-care system delay was seen in 79.9% of the patients. Choosing pharmacy for initial treatment (adjusted odds ratio [aOR] = 5.217), unskilled occupation (aOR = 3.717), female gender (aOR = 3.467), previously not heard about TB (aOR = 3.410), and lower education level (aOR = 2.774) were the independent predictors of the patient delay. Visiting two or more doctors (aOR = 5.855) and initially visiting a doctor of undergraduate qualification (aOR = 3.650) were the independent predictors of health-care system delay. The diagnosis in private sector (aOR = 8.989), not being admitted (aOR = 3.441), and age above 60 years (aOR = 0.394) was the independent predictors of treatment delay. Conclusion: Initial treatment from pharmacy, consulting multiple physicians, and diagnosis by private sector cause significant delay in diagnosis and treatment of pulmonary TB.


Asunto(s)
Tuberculosis Pulmonar , Tuberculosis , Humanos , Femenino , Persona de Mediana Edad , Tiempo de Tratamiento , Estudios Transversales , Diagnóstico Tardío , India/epidemiología , Tuberculosis Pulmonar/diagnóstico , Tuberculosis Pulmonar/tratamiento farmacológico , Tuberculosis Pulmonar/epidemiología
15.
Nat Commun ; 13(1): 5620, 2022 09 24.
Artículo en Inglés | MEDLINE | ID: mdl-36153390

RESUMEN

Alzheimer's disease (AD) is a chronic neurodegenerative disease characterized by the progressive accumulation of amyloid-beta and neurofibrillary tangles of tau in the neocortex. We profiled DNA methylation in two regions of the cortex from 631 donors, performing an epigenome-wide association study of multiple measures of AD neuropathology. We meta-analyzed our results with those from previous studies of DNA methylation in AD cortex (total n = 2013 donors), identifying 334 cortical differentially methylated positions (DMPs) associated with AD pathology including methylomic variation at loci not previously implicated in dementia. We subsequently profiled DNA methylation in NeuN+ (neuronal-enriched), SOX10+ (oligodendrocyte-enriched) and NeuN-/SOX10- (microglia- and astrocyte-enriched) nuclei, finding that the majority of DMPs identified in 'bulk' cortex tissue reflect DNA methylation differences occurring in non-neuronal cells. Our study highlights the power of utilizing multiple measures of neuropathology to identify epigenetic signatures of AD and the importance of characterizing disease-associated variation in purified cell-types.


Asunto(s)
Enfermedad de Alzheimer , Enfermedades Neurodegenerativas , Enfermedad de Alzheimer/metabolismo , Metilación de ADN/genética , Epigénesis Genética , Humanos , Enfermedades Neurodegenerativas/genética , Ovillos Neurofibrilares/genética , Ovillos Neurofibrilares/metabolismo
16.
Med J Armed Forces India ; 78(Suppl 1): S179-S185, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36147423

RESUMEN

Background: Studies among type 2 diabetes mellitus patients have reported total caries experience; however the severity and clinical consequences of untreated dental caries are often ignored. Methods: For this study, 150 well (I) and poorly controlled (II) diabetic participants were recruited. The spectrum of caries was evaluated using DMFT (Decayed, Missing and Filled Tooth) index, Dental Caries Severity Classification Scale, PUFA (Pulpal involvement, Ulceration, Fistula and Abscess) index, RCI (Root Caries Index) and the severity of radicular caries by Root Surface Caries Severity Index. Results: The prevalence of coronal and root caries was 90.7% and 23.3%, respectively. There was significant difference among caries experiences for D, M and DMFT. In group II, severity of coronal caries and mean rank of P, F, A and PUFA scores were higher, so were prevalence of root caries and severity of RD2, RD3 and RD4. HbA1c level had positive correlation with DMFT and PUFA scores (r = 0.458 and 0.522), so was the duration of diabetes with coronal caries, DMFT, PUFA score, root caries and RCI score (r = 0.235, 0.320, 0.273, 0.308 and 0.323). Conclusion: This is probably the first study to examine the severity of coronal caries, prevalence of untreated dental caries and severity of radicular caries in diabetic patients. Uncontrolled diabetes causes substantial increase in prevalence and severity of coronal and radicular caries.

17.
Nat Commun ; 13(1): 4932, 2022 08 22.
Artículo en Inglés | MEDLINE | ID: mdl-35995800

RESUMEN

Parkinson's disease (PD) and dementia with Lewy bodies (DLB) are closely related progressive disorders with no available disease-modifying therapy, neuropathologically characterized by intraneuronal aggregates of misfolded α-synuclein. To explore the role of DNA methylation changes in PD and DLB pathogenesis, we performed an epigenome-wide association study (EWAS) of 322 postmortem frontal cortex samples and replicated results in an independent set of 200 donors. We report novel differentially methylated replicating loci associated with Braak Lewy body stage near TMCC2, SFMBT2, AKAP6 and PHYHIP. Differentially methylated probes were independent of known PD genetic risk alleles. Meta-analysis provided suggestive evidence for a differentially methylated locus within the chromosomal region affected by the PD-associated 22q11.2 deletion. Our findings elucidate novel disease pathways in PD and DLB and generate hypotheses for future molecular studies of Lewy body pathology.


Asunto(s)
Enfermedad por Cuerpos de Lewy , Enfermedad de Parkinson , Epigenoma , Lóbulo Frontal/patología , Humanos , Cuerpos de Lewy/metabolismo , Enfermedad por Cuerpos de Lewy/genética , Metilación , Enfermedad de Parkinson/genética , Enfermedad de Parkinson/metabolismo , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismo
18.
Int Psychogeriatr ; 34(10): 905-917, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35852256

RESUMEN

OBJECTIVES: To examine the costs and cost-effectiveness of mirtazapine compared to placebo over 12-week follow-up. DESIGN: Economic evaluation in a double-blind randomized controlled trial of mirtazapine vs. placebo. SETTING: Community settings and care homes in 26 UK centers. PARTICIPANTS: People with probable or possible Alzheimer's disease and agitation. MEASUREMENTS: Primary outcome included incremental cost of participants' health and social care per 6-point difference in CMAI score at 12 weeks. Secondary cost-utility analyses examined participants' and unpaid carers' gain in quality-adjusted life years (derived from EQ-5D-5L, DEMQOL-Proxy-U, and DEMQOL-U) from the health and social care and societal perspectives. RESULTS: One hundred and two participants were allocated to each group; 81 mirtazapine and 90 placebo participants completed a 12-week assessment (87 and 95, respectively, completed a 6-week assessment). Mirtazapine and placebo groups did not differ on mean CMAI scores or health and social care costs over the study period, before or after adjustment for center and living arrangement (independent living/care home). On the primary outcome, neither mirtazapine nor placebo could be considered a cost-effective strategy with a high level of confidence. Groups did not differ in terms of participant self- or proxy-rated or carer self-rated quality of life scores, health and social care or societal costs, before or after adjustment. CONCLUSIONS: On cost-effectiveness grounds, the use of mirtazapine cannot be recommended for agitated behaviors in people living with dementia. Effective and cost-effective medications for agitation in dementia remain to be identified in cases where non-pharmacological strategies for managing agitation have been unsuccessful.


Asunto(s)
Demencia , Cuidadores , Análisis Costo-Beneficio , Demencia/complicaciones , Humanos , Mirtazapina/uso terapéutico , Calidad de Vida
19.
Schizophr Bull ; 48(6): 1263-1272, 2022 11 18.
Artículo en Inglés | MEDLINE | ID: mdl-35857752

RESUMEN

BACKGROUND AND HYPOTHESIS: Clozapine is the most effective antipsychotic for treatment-resistant schizophrenia, yet a significant proportion of individuals on clozapine continue to experience disabling symptoms, despite being treated with an adequate dose. There is a need for adjunct treatments to augment clozapine, notably for negative and cognitive symptoms. One such potential agent is the glutathione precursor N-acetylcysteine (NAC). STUDY DESIGN: A randomized double-blind, multi-center, placebo-controlled trial for clozapine patients with enduring psychotic symptoms (n = 84) was undertaken to investigate the efficacy of adjunctive NAC (2 g daily) for negative symptoms, cognition and quality of life (QoL). Efficacy was assessed at 8, 24, and 52 weeks. STUDY RESULTS: NAC did not significantly improve negative symptoms (P = .62), overall cognition (P = .71) or quality of life (Manchester quality of life: P = .11; Assessment of quality of life: P = .57) at any time point over a 1-year period of treatment. There were no differences in reported side effects between the groups (P = .26). CONCLUSIONS: NAC did not significantly improve schizophrenia symptoms, cognition, or quality of life in treatment-resistant patients taking clozapine. This trial was registered with "Australian and New Zealand Clinical Trials" on the 30 May, 2016 (Registration Number: ACTRN12615001273572).


Asunto(s)
Antipsicóticos , Clozapina , Esquizofrenia , Humanos , Clozapina/efectos adversos , Esquizofrenia/tratamiento farmacológico , Esquizofrenia/inducido químicamente , Acetilcisteína/farmacología , Calidad de Vida/psicología , Resultado del Tratamiento , Australia , Antipsicóticos/efectos adversos , Método Doble Ciego
20.
J Am Chem Soc ; 144(25): 11189-11202, 2022 06 29.
Artículo en Inglés | MEDLINE | ID: mdl-35704840

RESUMEN

Photoredox catalysts are primarily selected based on ground and excited state properties, but their activity is also intrinsically tied to the nature of their reduced (or oxidized) intermediates. Catalyst reactivity often necessitates an inherent instability, thus these intermediates represent a mechanistic turning point that affords either product formation or side-reactions. In this work, we explore the scope of a previously demonstrated side-reaction that partially saturates one pyridine ring of the ancillary ligand in heteroleptic iridium(III) complexes. Using high-throughput synthesis and screening under photochemical conditions, we identified different chemical pathways, ultimately governed by ligand composition. The ancillary ligand was the key factor that determined photochemical stability. Following photoinitiated electron transfer from a sacrificial tertiary amine, the reduced intermediate of complexes containing 1,10-phenanthroline derivatives exhibited long-term stability. In contrast, complexes containing 2,2'-bipyridines were highly susceptible to hydrogen atom transfer and ancillary ligand modification. Detailed characterization of selected complexes before and after transformation showed differing effects on the ground and excited state reduction potentials dependent on the nature of the cyclometalating ligands and excited states. The implications of catalyst stability and reactivity in chemical synthesis was demonstrated in a model photoredox reaction.


Asunto(s)
Iridio , Fenantrolinas , Hidrógeno , Iridio/química , Ligandos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...