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1.
Artigo em Inglês | MEDLINE | ID: mdl-37552493

RESUMO

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.


Assuntos
Antineoplásicos , Carcinoma Basocelular , Piridinas , Neoplasias Cutâneas , Humanos , Idoso , Proteínas Hedgehog/uso terapêutico , Resultado do Tratamento , Carcinoma Basocelular/patologia , Anilidas/uso terapêutico , Antineoplásicos/efeitos adversos , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/patologia
2.
Ophthalmic Plast Reconstr Surg ; 40(1): 18-29, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38241616

RESUMO

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.


Assuntos
Carcinoma de Células Escamosas , Neoplasias da Túnica Conjuntiva , Linfoma , Melanoma , Neoplasias Cutâneas , Animais , Humanos , Camundongos , Carcinoma de Células Escamosas/patologia , Neoplasias da Túnica Conjuntiva/terapia , Imunoterapia , Linfoma/patologia , Melanoma/tratamento farmacológico , Rituximab/uso terapêutico
3.
Angew Chem Int Ed Engl ; 63(21): e202319047, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38519420

RESUMO

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.

4.
Anal Chem ; 95(18): 7372-7378, 2023 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-37098243

RESUMO

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.


Assuntos
Medições Luminescentes , Microscopia , Medições Luminescentes/métodos , Fotometria , Luminescência , Membrana Celular
5.
J Neuroinflammation ; 20(1): 111, 2023 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-37158957

RESUMO

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.


Assuntos
Doença de Alzheimer , Demência , Neocórtex , Doença de Parkinson , Humanos , Citocinas , Fator Estimulador de Colônias de Granulócitos e Macrófagos , Interleucina-10 , Interleucina-13 , Doenças Neuroinflamatórias , Placa Amiloide
6.
J Org Chem ; 88(10): 6445-6453, 2023 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-36629260

RESUMO

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.

7.
Macromol Rapid Commun ; : e2300274, 2023 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-37474483

RESUMO

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.

8.
J Am Chem Soc ; 144(25): 11189-11202, 2022 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-35704840

RESUMO

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.


Assuntos
Irídio , Fenantrolinas , Hidrogênio , Irídio/química , Ligantes
9.
Lancet ; 398(10310): 1487-1497, 2021 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-34688369

RESUMO

BACKGROUND: Agitation is common in people with dementia and negatively affects the quality of life of both people with dementia and carers. Non-drug patient-centred care is the first-line treatment, but there is a need for other treatment when this care is not effective. Current evidence is sparse on safer and effective alternatives to antipsychotics. We assessed the efficacy and safety of mirtazapine, an antidepressant prescribed for agitation in dementia. METHODS: This parallel-group, double-blind, placebo-controlled trial-the Study of Mirtazapine for Agitated Behaviours in Dementia trial (SYMBAD)-was done in 26 UK centres. Participants had probable or possible Alzheimer's disease, agitation unresponsive to non-drug treatment, and a Cohen-Mansfield Agitation Inventory (CMAI) score of 45 or more. They were randomly assigned (1:1) to receive either mirtazapine (titrated to 45 mg) or placebo. The primary outcome was reduction in CMAI score at 12 weeks. This trial is registered with ClinicalTrials.gov, NCT03031184, and ISRCTN17411897. FINDINGS: Between Jan 26, 2017, and March 6, 2020, 204 participants were recruited and randomised. Mean CMAI scores at 12 weeks were not significantly different between participants receiving mirtazapine and participants receiving placebo (adjusted mean difference -1·74, 95% CI -7·17 to 3·69; p=0·53). The number of controls with adverse events (65 [64%] of 102 controls) was similar to that in the mirtazapine group (67 [66%] of 102 participants receiving mirtazapine). However, there were more deaths in the mirtazapine group (n=7) by week 16 than in the control group (n=1), with post-hoc analysis suggesting this difference was of marginal statistical significance (p=0·065). INTERPRETATION: This trial found no benefit of mirtazapine compared with placebo, and we observed a potentially higher mortality with use of mirtazapine. The data from this study do not support using mirtazapine as a treatment for agitation in dementia. FUNDING: UK National Institute for Health Research Health Technology Assessment Programme.


Assuntos
Ansiolíticos , Demência/complicações , Mirtazapina , Agitação Psicomotora/tratamento farmacológico , Idoso de 80 Anos ou mais , Ansiolíticos/efeitos adversos , Ansiolíticos/uso terapêutico , Escalas de Graduação Psiquiátrica Breve , Cuidadores/psicologia , Método Duplo-Cego , Feminino , Humanos , Masculino , Mirtazapina/efeitos adversos , Mirtazapina/uso terapêutico , Qualidade de Vida/psicologia , Reino Unido
10.
Mol Psychiatry ; 26(10): 5766-5788, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-32647257

RESUMO

A population of more than six million people worldwide at high risk of Alzheimer's disease (AD) are those with Down Syndrome (DS, caused by trisomy 21 (T21)), 70% of whom develop dementia during lifetime, caused by an extra copy of ß-amyloid-(Aß)-precursor-protein gene. We report AD-like pathology in cerebral organoids grown in vitro from non-invasively sampled strands of hair from 71% of DS donors. The pathology consisted of extracellular diffuse and fibrillar Aß deposits, hyperphosphorylated/pathologically conformed Tau, and premature neuronal loss. Presence/absence of AD-like pathology was donor-specific (reproducible between individual organoids/iPSC lines/experiments). Pathology could be triggered in pathology-negative T21 organoids by CRISPR/Cas9-mediated elimination of the third copy of chromosome 21 gene BACE2, but prevented by combined chemical ß and γ-secretase inhibition. We found that T21 organoids secrete increased proportions of Aß-preventing (Aß1-19) and Aß-degradation products (Aß1-20 and Aß1-34). We show these profiles mirror in cerebrospinal fluid of people with DS. We demonstrate that this protective mechanism is mediated by BACE2-trisomy and cross-inhibited by clinically trialled BACE1 inhibitors. Combined, our data prove the physiological role of BACE2 as a dose-sensitive AD-suppressor gene, potentially explaining the dementia delay in ~30% of people with DS. We also show that DS cerebral organoids could be explored as pre-morbid AD-risk population detector and a system for hypothesis-free drug screens as well as identification of natural suppressor genes for neurodegenerative diseases.


Assuntos
Doença de Alzheimer , Síndrome de Down , Doença de Alzheimer/genética , Secretases da Proteína Precursora do Amiloide/genética , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Ácido Aspártico Endopeptidases/genética , Ácido Aspártico Endopeptidases/metabolismo , Encéfalo/metabolismo , Síndrome de Down/genética , Genes Supressores , Humanos , Organoides/metabolismo , Trissomia
11.
Int Psychogeriatr ; 34(10): 905-917, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35852256

RESUMO

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.


Assuntos
Demência , Cuidadores , Análise Custo-Benefício , Demência/complicações , Humanos , Mirtazapina/uso terapêutico , Qualidade de Vida
12.
Indian J Public Health ; 66(Supplement): S60-S65, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36412476

RESUMO

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.


Assuntos
Tuberculose Pulmonar , Tuberculose , Humanos , Feminino , Pessoa de Meia-Idade , Tempo para o Tratamento , Estudos Transversais , Diagnóstico Tardio , Índia/epidemiologia , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/epidemiologia
13.
Med J Armed Forces India ; 78(Suppl 1): S179-S185, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36147423

RESUMO

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.

14.
Brain ; 143(12): 3842-3849, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33188391

RESUMO

There is clinical overlap between presentations of dementia due to limbic-predominant age-related TDP-43 encephalopathy (LATE) and Alzheimer's disease. It has been suggested that the combination of Alzheimer's disease neuropathological change (ADNC) and LATE neuropathological changes (LATE-NC) is associated with greater neuropsychiatric symptom burden, compared to either pathology alone. Longitudinal Neuropsychiatric Inventory and psychotropic medication prescription data from neuropathologically diagnosed pure ADNC (n = 78), pure LATE-NC (n = 14) and mixed ADNC/LATE-NC (n = 39) brain bank donors were analysed using analysis of variance and linear mixed effects regression models to examine the relationship between diagnostic group and neuropsychiatric symptom burden. Nearly all donors had dementia; three (two pure LATE-NC and one pure ADNC) donors had mild cognitive impairment and another two donors with LATE-NC did not have dementia. The mixed ADNC/LATE-NC group was older than the pure ADNC group, had a higher proportion of females compared to the pure ADNC and LATE-NC groups, and had more severe dementia versus the pure LATE-NC group. After adjustment for length of follow-up, cognitive and demographic factors, mixed ADNC/LATE-NC was associated with lower total Neuropsychiatric Inventory and agitation factor scores than pure ADNC, and lower frontal factor scores than pure LATE-NC. Our findings indicate that concomitant LATE pathology in Alzheimer's disease is not associated with greater neuropsychiatric symptom burden. Future longitudinal studies are needed to further investigate whether mixed ADNC/LATE-NC may be protective against agitation and frontal symptoms in dementia caused by Alzheimer's disease or LATE pathology.


Assuntos
Doença de Alzheimer/complicações , Encefalite Límbica/complicações , Transtornos Mentais/etiologia , Proteinopatias TDP-43/complicações , Idoso , Idoso de 80 Anos ou mais , Envelhecimento , Doença de Alzheimer/psicologia , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/psicologia , Estudos de Coortes , Proteínas de Ligação a DNA , Feminino , Humanos , Encefalite Límbica/psicologia , Estudos Longitudinais , Masculino , Transtornos Mentais/psicologia , Testes Neuropsicológicos , Escalas de Graduação Psiquiátrica , Caracteres Sexuais , Fatores Socioeconômicos , Proteinopatias TDP-43/psicologia
15.
Brain ; 143(12): 3763-3775, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33300551

RESUMO

Human DNA methylation data have been used to develop biomarkers of ageing, referred to as 'epigenetic clocks', which have been widely used to identify differences between chronological age and biological age in health and disease including neurodegeneration, dementia and other brain phenotypes. Existing DNA methylation clocks have been shown to be highly accurate in blood but are less precise when used in older samples or in tissue types not included in training the model, including brain. We aimed to develop a novel epigenetic clock that performs optimally in human cortex tissue and has the potential to identify phenotypes associated with biological ageing in the brain. We generated an extensive dataset of human cortex DNA methylation data spanning the life course (n = 1397, ages = 1 to 108 years). This dataset was split into 'training' and 'testing' samples (training: n = 1047; testing: n = 350). DNA methylation age estimators were derived using a transformed version of chronological age on DNA methylation at specific sites using elastic net regression, a supervised machine learning method. The cortical clock was subsequently validated in a novel independent human cortex dataset (n = 1221, ages = 41 to 104 years) and tested for specificity in a large whole blood dataset (n = 1175, ages = 28 to 98 years). We identified a set of 347 DNA methylation sites that, in combination, optimally predict age in the human cortex. The sum of DNA methylation levels at these sites weighted by their regression coefficients provide the cortical DNA methylation clock age estimate. The novel clock dramatically outperformed previously reported clocks in additional cortical datasets. Our findings suggest that previous associations between predicted DNA methylation age and neurodegenerative phenotypes might represent false positives resulting from clocks not robustly calibrated to the tissue being tested and for phenotypes that become manifest in older ages. The age distribution and tissue type of samples included in training datasets need to be considered when building and applying epigenetic clock algorithms to human epidemiological or disease cohorts.


Assuntos
Envelhecimento/genética , Relógios Biológicos/fisiologia , Córtex Cerebral/crescimento & desenvolvimento , Epigênese Genética/fisiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Contagem de Células , Córtex Cerebral/citologia , Criança , Pré-Escolar , DNA/genética , Metilação de DNA , Bases de Dados Factuais , Feminino , Humanos , Lactente , Aprendizado de Máquina , Masculino , Pessoa de Meia-Idade , Neurônios/fisiologia , Fenótipo , Reprodutibilidade dos Testes , Caracteres Sexuais , Adulto Jovem
16.
Alzheimers Dement ; 17(7): 1121-1133, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33663011

RESUMO

INTRODUCTION: The aged brain frequently exhibits multiple pathologies, rather than a single hallmark pathology (pure pathology [PurP]), ranging from low/intermediate levels of additional pathology (LowP) to mixed severe pathology (mixed SevP). We investigated the frequency of PurP, LowP, and mixed SevP, and the impact of additional LowP on cognition. METHODS: Data came from 670 cases from the Brains for Dementia research program. Cases were categorized into PurP, mixed SevP, or a main disease with additional LowP; 508 cases had a clinical dementia rating. RESULTS: 69.9% of cases had LowP, 22.7% had PurP, and 7.5% had mixed SevP. Additional LowP increased the likelihood of having mild dementia versus mild cognitive impairment (MCI) by almost 20-fold (odds ratio = 19.5). DISCUSSION: Most aged individuals have multiple brain pathologies. The presence of one additional LowP can significantly worsen cognitive decline, increasing the risk of transitioning from MCI to dementia 20-fold. Multimorbidity should be considered in dementia research and clinical studies.


Assuntos
Autopsia , Encéfalo/patologia , Disfunção Cognitiva/patologia , Demência/patologia , Multimorbidade , Idoso de 80 Anos ou mais , Peptídeos beta-Amiloides , Feminino , Humanos , Masculino , Testes de Estado Mental e Demência/estatística & dados numéricos , Tauopatias/patologia
17.
J Neurol Neurosurg Psychiatry ; 91(5): 512-519, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32213570

RESUMO

Visual hallucinations are common in older people and are especially associated with ophthalmological and neurological disorders, including dementia and Parkinson's disease. Uncertainties remain whether there is a single underlying mechanism for visual hallucinations or they have different disease-dependent causes. However, irrespective of mechanism, visual hallucinations are difficult to treat. The National Institute for Health Research (NIHR) funded a research programme to investigate visual hallucinations in the key and high burden areas of eye disease, dementia and Parkinson's disease, culminating in a workshop to develop a unified framework for their clinical management. Here we summarise the evidence base, current practice and consensus guidelines that emerged from the workshop.Irrespective of clinical condition, case ascertainment strategies are required to overcome reporting stigma. Once hallucinations are identified, physical, cognitive and ophthalmological health should be reviewed, with education and self-help techniques provided. Not all hallucinations require intervention but for those that are clinically significant, current evidence supports pharmacological modification of cholinergic, GABAergic, serotonergic or dopaminergic systems, or reduction of cortical excitability. A broad treatment perspective is needed, including carer support. Despite their frequency and clinical significance, there is a paucity of randomised, placebo-controlled clinical trial evidence where the primary outcome is an improvement in visual hallucinations. Key areas for future research include the development of valid and reliable assessment tools for use in mechanistic studies and clinical trials, transdiagnostic studies of shared and distinct mechanisms and when and how to treat visual hallucinations.


Assuntos
Oftalmopatias/complicações , Alucinações/etiologia , Doenças do Sistema Nervoso/complicações , Demência/complicações , Demência/fisiopatologia , Demência/terapia , Oftalmopatias/fisiopatologia , Oftalmopatias/terapia , Alucinações/fisiopatologia , Alucinações/terapia , Humanos , Doenças do Sistema Nervoso/fisiopatologia , Doenças do Sistema Nervoso/terapia , Doença de Parkinson/complicações , Doença de Parkinson/fisiopatologia , Doença de Parkinson/terapia
18.
Am J Geriatr Psychiatry ; 28(1): 75-86, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31327631

RESUMO

OBJECTIVE: Prevalence of Lewy body dementias (LBD) is second only to Alzheimer's disease (AD) among people with neurodegenerative dementia. LBD cause earlier mortality, more intense neuropsychiatric symptoms, more caregivers' burden, and higher costs than AD. The molecular mechanisms underlying LBD are largely unknown. As advancing molecular level mechanistic understanding is essential for identifying reliable peripheral biomarkers and novel therapeutic targets for LBD, the authors aimed to identify differentially expressed genes (DEG), and dysfunctional molecular networks in postmortem LBD brains. METHODS: The authors investigated the transcriptomics of postmortem anterior cingulate and dorsolateral prefrontal cortices of people with pathology-verified LBD using next-generation RNA-sequencing. The authors verified the identified DEG using high-throughput quantitative polymerase chain reactions. Functional implications of identified DEG and the consequent metabolic reprogramming were evaluated by Ingenuity pathway analyses, genome-scale metabolic modeling, reporter metabolite analyses, and in silico gene silencing. RESULTS: The authors identified and verified 12 novel DEGs (MPO, SELE, CTSG, ALPI, ABCA13, GALNT6, SST, RBM3, CSF3, SLC4A1, OXTR, and RAB44) in LBD brains with genome-wide statistical significance. The authors documented statistically significant down-regulation of several cytokine genes. Identified dysfunctional molecular networks highlighted the contributions of mitochondrial dysfunction, oxidative stress, and immunosenescence toward neurodegeneration in LBD. CONCLUSION: Our findings support that chronic microglial activation and neuroinflammation, well-documented in AD, are notably absent in LBD. The lack of neuroinflammation in LBD brains was corroborated by statistically significant down-regulation of several inflammatory markers. Identified DEGs, especially down-regulated inflammatory markers, may aid distinguishing LBD from AD, and their biomarker potential warrant further investigation.


Assuntos
Encéfalo/metabolismo , Giro do Cíngulo/metabolismo , Inflamação/metabolismo , Doença por Corpos de Lewy/metabolismo , Córtex Pré-Frontal/metabolismo , Transcriptoma , Diagnóstico , Regulação para Baixo , Giro do Cíngulo/patologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Inflamação/patologia , Doença por Corpos de Lewy/patologia , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Córtex Pré-Frontal/patologia , Análise de Sequência de RNA , Bancos de Tecidos , Reino Unido , Regulação para Cima
19.
Nutr Neurosci ; 23(2): 139-148, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29847303

RESUMO

Objectives: Schizophrenia is a debilitating psychiatric illness associated with positive and negative symptoms as well as significant impairments in cognition. Current antipsychotic medications do not alleviate these cognitive deficits, and more effective therapeutic options are required. Increased oxidative stress and altered antioxidant levels, including glutathione (GSH) have been observed both in individuals with cognitive impairment and in people with schizophrenia. A GSH precursor, the antioxidant N-acetylcysteine (NAC) has been investigated as a novel treatment for the cognitive symptoms of schizophrenia, and recent research suggests that NAC may be a promising adjunctive treatment option. However, the current literature lacks integration as to why NAC may effectively improve cognition in schizophrenia. The present theoretical synthesis aimed to address this gap by examining the processes by which NAC may improve cognitive function in schizophrenia. Methods: The schizophrenia literature was reviewed in three key domains: cognitive impairment, the relationship between oxidative stress and cognition, and the efficacy of NAC as a novel treatment. This led to a theoretical analysis of the neurobiological processes by which NAC may improve cognition in schizophrenia. Results: This theoretical review concluded that improved cognition may result from a combination of factors, including decreased oxidative stress, neuroprotection of cognitive networks and an increase in glutamatergic modulation of the N-methyl-d-aspartate receptor system. Whilst a number of mechanisms by which NAC may improve cognition and symptoms in schizophrenia have been proposed, there is still limited understanding of the specific metabolic pathways involved and how they interrelate and modify specific symptomology. Discussion: Exploration of how NAC treatment may act to improve cognitive function could guide clinical trials by investigation of the specific neurotransmitter systems and processes involved, allowing for targeted neurological outcome measures. Future research would benefit from the investigation of both in vivo cortical GSH concentration and peripheral plasma GSH in a population of individuals with chronic schizophrenia.


Assuntos
Acetilcisteína/uso terapêutico , Cognição/efeitos dos fármacos , Esquizofrenia/tratamento farmacológico , Esquizofrenia/fisiopatologia , Cognição/fisiologia , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/fisiopatologia , Glutationa/fisiologia , Humanos , Fármacos Neuroprotetores , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Receptores de N-Metil-D-Aspartato/efeitos dos fármacos , Receptores de N-Metil-D-Aspartato/fisiologia
20.
J Am Chem Soc ; 141(44): 17646-17658, 2019 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-31545022

RESUMO

We report the discovery of a tandem catalytic process to reduce energy demanding substrates, using the [Ir(ppy)2(dtb-bpy)]+ (1+) photocatalyst. The immediate products of photoinitiated electron transfer (PET) between 1+ and triethylamine (TEA) undergo subsequent reactions to generate a previously unknown, highly reducing species (2). Formation of 2 occurs via reduction and semisaturation of the ancillary dtb-bpy ligand, where the TEA radical cation serves as an effective hydrogen atom donor, confirmed by nuclear magnetic resonance, mass spectrometry, and deuterium labeling experiments. Steady-state and time-resolved luminescence and absorption studies reveal that upon irradiation, 2 undergoes electron transfer or proton-coupled electron transfer (PCET) with a representative acceptor (N-(diphenylmethylene)-1-phenylmethanamine; S). Turnover of this new photocatalytic cycle occurs along with the reformation of 1+. We rationalize our observations by proposing the first example of a mechanistic pathway where two distinct yet interconnected photoredox cycles provide access to an extended reduction potential window capable of engaging a wide range of energy demanding and synthetically relevant organic substrates including aryl halides.

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