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1.
J Neurosci ; 43(45): 7657-7667, 2023 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-37833068

RESUMO

Worldwide, alcohol use and abuse are a leading risk of mortality, causing 5.3% of all deaths (World Health Organization, 2022). The endocrine stress system, initiated by the peripheral release of corticotropin releasing hormone (CRH) from primarily glutamatergic neurons in the paraventricular nucleus of the hypothalamus (PVN), is profoundly linked with alcohol use, abuse, and relapse (Blaine and Sinha, 2017). These PVN CRH-releasing (PVNCRH) neurons are essential for peripheral and central stress responses (Rasiah et al., 2023), but little is known about how alcohol affects these neurons. Here, we show that two-bottle choice alcohol consumption blunts the endocrine-mediated corticosterone response to stress during acute withdrawal in female mice. Conversely, using slice electrophysiology, we demonstrate that acute withdrawal engenders a hyperexcitable phenotype of PVNCRH neurons in females that is accompanied by increased glutamatergic transmission in both male and female mice. GABAergic synaptic transmission was unaffected by alcohol history. We then tested whether chemogenetic inhibition of PVNCRH neurons would restore stress response in female mice with a history of alcohol drinking in the looming disk test, which mimics an approaching predator threat. Accordingly, inhibition of PVNCRH neurons reduced active escape in hM4Di alcohol history mice only. This study indicates that stress-responsive PVNCRH neurons in females are particularly affected by a history of alcohol consumption. Interestingly, women have indicated an increase in heavy alcohol use to cope with stress (Rodriguez et al., 2020), perhaps pointing to a potential underlying mechanism in alcohol-mediated changes to PVNCRH neurons that alter stress response.SIGNIFICANCE STATEMENT Paraventricular nucleus of the hypothalamus neurons that release corticotropin releasing hormone (PVNCRH) are vital for stress response. These neurons have been understudied in relation to alcohol and withdrawal despite profound relations between stress, alcohol use disorders (AUD), and relapse. In this study, we use a variety of techniques to show that acute withdrawal from a history of alcohol impacts peripheral stress response, PVNCRH neurons, and behavior. Specifically, PVNCRH are in a hyperactive state during withdrawal, which drives an increase in active stress coping behaviors in female mice only. Understanding how alcohol use and withdrawal affects stress responding PVNCRH neurons may contribute to finding new potential targets for the treatment of alcohol use disorder.


Assuntos
Alcoolismo , Hormônio Liberador da Corticotropina , Humanos , Feminino , Masculino , Camundongos , Animais , Hormônio Liberador da Corticotropina/metabolismo , Hormônio Adrenocorticotrópico , Hormônios Liberadores de Hormônios Hipofisários , Hipotálamo/metabolismo , Núcleo Hipotalâmico Paraventricular/metabolismo , Neurônios/fisiologia , Consumo de Bebidas Alcoólicas , Recidiva
2.
Langmuir ; 2024 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-39333840

RESUMO

Fractal formation in spin-coated thin-film polymers is of experimental and theoretical interest. Modeling the determinants and dynamics of this process will deepen our understanding of polymer aggregation and the predictability of thin-film structures. This is especially true if the model used has readily interpretable parameters and has been demonstrated to yield a close match to experimental processes under a variety of conditions. In this work, we adapted and applied a relatively new model of fractal growth comprised of a spreading and contracting triangular network, to model spin-coated, thin-film polymers made of poly(vinyl alcohol) on polydimethylsiloxane substrates. We drew clear connections between model parameters and the process of polymer aggregation and we demonstrated the ability of the model to simulate fractal formation under a wide variety of conditions including varying the degree of hydrolysis of the polymer, changing the spin-coating process, and solvent annealing and reforming of polymer fractals under different drying conditions. We also showed how the model is able to replicate idiosyncratic experimental settings yielding novel fractal patterns.

3.
J Thromb Thrombolysis ; 57(4): 677-682, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38556578

RESUMO

Venous thromboembolism (VTE) and stroke carry significant mortality and morbidity in cancer patients. Direct oral anticoagulants (DOACs) have been demonstrated to be effective for the treatment of VTE and prevention of stroke in atrial fibrillation (AF). Bleeding rates are variable and are based on the cancer type and the patient's specific risk factors. There are approved specific antidotes for DOAC-associated bleeding. Other strategies are available for bleeding reversal, including the use of prothrombin complex concentrate (PCC). No randomized studies have compared head-to-head the efficacy and safety of reversal agents. We aim to examine the safety and effectiveness of hemostatic agents in cancer patients with DOAC-related major bleeding. A retrospective chart review study of patients at MD Anderson Cancer Center with DOAC-related major bleeding between 2014 and 2019. Bleeding severity and clinical hemostasis were described based on ISTH guidelines and the Sarode criteria, respectively. The rates of thrombotic complications and mortality at 30-day from the index bleeding event were described. We identified 23 patients with DOAC-related major bleeding; 14 patients received PCC and 9 patients received andexanet alfa. The most common sites of bleeding were the gastrointestinal tract and intracranial. Effective hemostasis and 30-day mortality were similar to reported results from other reports of outcomes of reversal agents for DOAC related-bleeding in non-cancer patients. One patient in each treatment group experienced a thrombotic event. Further larger scale studies are needed to confirm our findings in cancer patients.


Assuntos
Neoplasias , Acidente Vascular Cerebral , Tromboembolia Venosa , Humanos , Anticoagulantes/uso terapêutico , Tromboembolia Venosa/tratamento farmacológico , Estudos Retrospectivos , Hemorragia/tratamento farmacológico , Acidente Vascular Cerebral/tratamento farmacológico , Administração Oral , Neoplasias/tratamento farmacológico
4.
J Biol Chem ; 293(3): 906-919, 2018 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-29191832

RESUMO

Anti-hinge antibodies (AHAs) are an autoantibody subclass that, following proteolytic cleavage, recognize cryptic epitopes exposed in the hinge regions of immunoglobulins (Igs) and do not bind to the intact Ig counterpart. AHAs have been postulated to exacerbate chronic inflammatory disorders such as inflammatory bowel disease and rheumatoid arthritis. On the other hand, AHAs may protect against invasive microbial pathogens and cancer. However, despite more than 50 years of study, the origin and specific B cell compartments that express AHAs remain elusive. Recent research on serum AHAs suggests that they arise during an active immune response, in contrast to previous proposals that they derive from the preexisting immune repertoire in the absence of antigenic stimuli. We report here the isolation and characterization of AHAs from memory B cells, although anti-hinge-reactive B cells were also detected in the naive B cell compartment. IgG AHAs cloned from a single human donor exhibited restricted specificity for protease-cleaved F(ab')2 fragments and did not bind the intact IgG counterpart. The cloned IgG-specific AHA-variable regions were mutated from germ line-derived sequences and displayed a high sequence variability, confirming that these AHAs underwent class-switch recombination and somatic hypermutation. Consistent with previous studies of serum AHAs, several of these clones recognized a linear, peptide-like epitope, but one clone was unique in recognizing a conformational epitope. All cloned AHAs could restore immune effector functions to proteolytically generated F(ab')2 fragments. Our results confirm that a diverse set of epitope-specific AHAs can be isolated from a single human donor.


Assuntos
Autoanticorpos/metabolismo , Linfócitos B/metabolismo , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/metabolismo , Autoanticorpos/imunologia , Linfócitos B/imunologia , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Humanos , Imunoglobulina G/imunologia , Imunoglobulina G/metabolismo , Metaloproteinase 3 da Matriz/metabolismo , Metaloproteinase 7 da Matriz/metabolismo
5.
Mult Scler ; 23(1): 94-105, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27003945

RESUMO

BACKGROUND: The Expanded Disability Status Scale (EDSS) has wide scientific and regulatory precedent but limited ability to detect clinically relevant disability progression in secondary progressive multiple sclerosis (SPMS) patients, partly due to a lack of meaningful measurement of short-distance ambulatory and upper-extremity function. OBJECTIVE: To present a rationale for a composite endpoint adding the timed 25-foot walk (T25FW) and 9-Hole Peg Test (9HPT) to EDSS for SPMS disability progression assessment. METHODS: Using the International Multiple Sclerosis Secondary Progressive Avonex Clinical Trial (IMPACT) placebo arm ( n = 215) data, we analyzed disability progression using a novel progression endpoint, "EDSS-Plus," defined as progression on ⩾1 of 3 components (EDSS, T25FW, and/or 9HPT) confirmed ⩾24 weeks apart and with a ⩾20% minimum threshold change for T25FW and 9HPT. RESULTS: Over 2 years, subjects classified as T25FW, 9HPT (dominant hand), or 9HPT (non-dominant hand) progressors worsened on average by 103.4%, 69.0%, and 59.2%, respectively, while non-progressors' times remained largely unchanged. Using EDSS-Plus, 59.5% of the patients had 24-week confirmed disability progression versus 24.7% (EDSS), 41.9% (T25FW), and 34.4% (9HPT (either hand)) on each component alone. CONCLUSION: The 24-week confirmed minimum worsening of ⩾20% for T25FW and 9HPT clearly separates SPMS progressors from non-progressors. We propose that EDSS-Plus may represent an improved endpoint to identify SPMS disability progression.


Assuntos
Esclerose Múltipla Crônica Progressiva/fisiopatologia , Adulto , Avaliação da Deficiência , Pessoas com Deficiência/reabilitação , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla Crônica Progressiva/diagnóstico , Índice de Gravidade de Doença , Fatores de Tempo , Extremidade Superior/fisiopatologia , Caminhada/fisiologia
6.
N Engl J Med ; 366(20): 1870-80, 2012 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-22591293

RESUMO

BACKGROUND: Progressive multifocal leukoencephalopathy (PML) is associated with natalizumab treatment. We quantified the risk of PML in patients with multiple sclerosis, according to the presence or absence of three risk factors: positive status with respect to anti-JC virus antibodies, prior use of immunosuppressants, and increasing duration of natalizumab treatment. METHODS: We used data from postmarketing sources, clinical studies, and an independent Swedish registry to estimate the incidence of PML among natalizumab-treated patients with multiple sclerosis, according to positive or negative status with respect to anti-JC virus antibodies, prior or no prior use of immunosuppressants, and duration of treatment (1 to 24 months vs. 25 to 48 months). Blood samples were available for anti-JC virus antibody testing from 5896 patients with multiple sclerosis and from 54 patients with multiple sclerosis who were treated with natalizumab and in whom PML later developed. RESULTS: As of February 29, 2012, there were 212 confirmed cases of PML among 99,571 patients treated with natalizumab (2.1 cases per 1000 patients). All 54 patients with PML for whom samples were available before the diagnosis were positive for anti-JC virus antibodies. When the risk of PML was stratified according to three risk factors, the risk of PML was lowest among the patients who were negative for anti-JC virus antibodies, with the incidence estimated to be 0.09 cases or less per 1000 patients (95% confidence interval [CI], 0 to 0.48). Patients who were positive for anti-JC virus antibodies, had taken immunosuppressants before the initiation of natalizumab therapy, and had received 25 to 48 months of natalizumab treatment had the highest estimated risk (incidence, 11.1 cases per 1000 patients [95% CI, 8.3 to 14.5]). CONCLUSIONS: Positive status with respect to anti-JC virus antibodies, prior use of immunosuppressants, and increased duration of natalizumab treatment, alone or in combination, were associated with distinct levels of PML risk in natalizumab-treated patients with multiple sclerosis. (Funded by Biogen Idec and Elan Pharmaceuticals.).


Assuntos
Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Antivirais/sangue , Imunossupressores/uso terapêutico , Vírus JC/imunologia , Leucoencefalopatia Multifocal Progressiva/induzido quimicamente , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Adolescente , Adulto , Idoso , Anticorpos Monoclonais Humanizados/uso terapêutico , Criança , Quimioterapia Combinada , Feminino , Humanos , Incidência , Leucoencefalopatia Multifocal Progressiva/epidemiologia , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla Recidivante-Remitente/imunologia , Natalizumab , Vigilância de Produtos Comercializados , Sistema de Registros , Fatores de Risco , Adulto Jovem
7.
Ann Neurol ; 76(6): 802-12, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25273271

RESUMO

OBJECTIVE: The increased risk of progressive multifocal leukoencephalopathy (PML) with natalizumab treatment is associated with the presence of anti-JC virus (JCV) antibodies. We analyzed whether anti-JCV antibody levels, measured as index, may further define PML risk in seropositive patients. METHODS: The association between serum or plasma anti-JCV antibody levels and PML risk was examined in anti-JCV antibody-positive multiple sclerosis (MS) patients from natalizumab clinical studies and postmarketing sources. For PML and non-PML patients, the probabilities of having an index below and above a range of anti-JCV antibody index thresholds were calculated using all available data and applied to the PML risk stratification algorithm. Longitudinal stability of anti-JCV antibody index was also evaluated. RESULTS: Anti-JCV antibody index data were available for serum/plasma samples collected >6 months prior to PML diagnosis from 71 natalizumab-treated PML patients and 2,522 non-PML anti-JCV antibody-positive patients. In patients with no prior immunosuppressant use, anti-JCV antibody index distribution was significantly higher in PML patients than in non-PML patients (p < 0.0001). Among patients who were anti-JCV antibody negative at baseline in the AFFIRM and STRATIFY-1 trials, 97% remained consistently negative or below an index threshold of 1.5 over 18 months. Retrospective analyses of pre-PML samples collected longitudinally from PML patients displayed sustained higher anti-JCV antibody index over time. INTERPRETATION: Anti-JCV antibody levels in serum/plasma, measured as index, may differentiate PML risk in anti-JCV antibody-positive MS patients with no prior immunosuppressant use. Continued evaluation of anti-JCV antibody index and PML risk is warranted.


Assuntos
Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Antivirais/sangue , Vírus JC/metabolismo , Leucoencefalopatia Multifocal Progressiva/sangue , Leucoencefalopatia Multifocal Progressiva/diagnóstico , Biomarcadores/sangue , Humanos , Leucoencefalopatia Multifocal Progressiva/induzido quimicamente , Estudos Longitudinais , Natalizumab , Fatores de Risco
8.
BMC Nephrol ; 16: 102, 2015 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-26162369

RESUMO

BACKGROUND: Rates of medication non-adherence in dialysis patients are high, and improving adherence is likely to improve outcomes. Few data are available regarding factors associated with medication adherence in dialysis patients, and these data are needed to inform effective intervention strategies. METHODS/DESIGN: This is an observational cross-sectional study of a multi-ethnic dialysis cohort from New Zealand, with the main data collection tool being an interviewer-assisted survey. A total of 100 participants were randomly sampled from a single centre, with selection stratified by ethnicity and dialysis modality (facility versus home). The main outcome measure is self-reported medication adherence using the Morisky 8-Item Medication Adherence Scale (MMAS-8). Study data include demographic, clinical, social and psychometric characteristics, the latter being constructs of health literacy, medication knowledge, beliefs about medications, and illness perceptions. Psychometric constructs were assessed through the following survey instruments; health literacy screening questions, the Medication Knowledge Evaluation Tool (Okuyan et al.), the Beliefs about Medication Questionnaire (Horne et al.), the Brief Illness Perception Questionnaire (Broadbent et al.). Using the study data, reliability analysis for internal consistency is satisfactory for the scales evaluating health literacy, medication knowledge, and beliefs about medications, with Chronbach's α > 0.7 for all. Reliability analysis indicated poor internal consistency for scales relating to illness perceptions. MMAS-8 and all psychometric scores are normally distributed in the study data. DISCUSSION: This study will provide important information on the factors involved in medication non-adherence in New Zealand dialysis patients. The resulting knowledge will inform long-term initiatives to reduce medication non-adherence in dialysis patients, and help ensure that they are addressing appropriate and evidence based targets for intervention.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Letramento em Saúde , Falência Renal Crônica/terapia , Adesão à Medicação , Diálise Renal , Estudos de Coortes , Estudos Transversais , Humanos , Havaiano Nativo ou Outro Ilhéu do Pacífico , Nova Zelândia , Psicometria , Autorrelato , Inquéritos e Questionários , População Branca
9.
PLoS One ; 19(2): e0298916, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38394129

RESUMO

Over the last 40 years, applied mathematicians and physicists have proposed a number of mathematical models that produce structures exhibiting a fractal dimension. This work has coincided with the discovery that objects with fractal dimension are relatively common in the natural and human-produced worlds. One particularly successful model of fractal growth is the diffusion limited aggregation (DLA) model, a model as notable for its simplicity as for its complex and varied behavior. It has been modified and used to simulate fractal growth processes in numerous experimental and empirical contexts. In this work, we present an alternative fractal growth model that is based on a growing mass that bonds to particles in a surrounding medium and then exerts a force on them in an iterative process of growth and contraction. The resulting structure is a spreading triangular network rather than an aggregate of spheres, and the model is conceptually straightforward. To the best of our knowledge, this model is unique and differs in its dynamics and behavior from the DLA model and related particle aggregation models. We explore the behavior of the model, demonstrate the range of model output, and show that model output can have a variable fractal dimension between 1.5 and 1.83 that depends on model parameters. We also apply the model to simulating the development of polymer thin films prepared using spin-coating which also exhibit variable fractal dimensions. We demonstrate how the model can be adjusted to different dewetting conditions as well as how it can be used to simulate the modification of the polymer morphology under solvent annealing.


Assuntos
Fractais , Polímeros , Humanos , Polímeros/química , Modelos Teóricos , Difusão
10.
Chem Biomed Imaging ; 2(1): 4-26, 2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38274040

RESUMO

Brachytherapy is an established treatment modality that has been globally utilized for the therapy of malignant solid tumors. However, classic therapeutic sealed sources used in brachytherapy must be surgically implanted directly into the tumor site and removed after the requisite period of treatment. In order to avoid the trauma involved in the surgical procedures and prevent undesirable radioactive distribution at the cancerous site, well-dispersed radiolabeled nanomaterials are now being explored for brachytherapy applications. This emerging field has been coined "nanoscale brachytherapy". Despite present-day advancements, an ongoing challenge is obtaining an advanced, functional nanomaterial that concurrently incorporates features of high radiolabeling yield, short labeling time, good radiolabeling stability, and long tumor retention time without leakage of radioactivity to the nontargeted organs. Further, attachment of suitable targeting ligands to the nanoplatforms would widen the nanoscale brachytherapy approach to tumors expressing various phenotypes. Molecular imaging using radiolabeled nanoplatforms enables noninvasive visualization of cellular functions and biological processes in vivo. In vivo imaging also aids in visualizing the localization and retention of the radiolabeled nanoplatforms at the tumor site for the requisite time period to render safe and effective therapy. Herein, we review the advancements over the last several years in the synthesis and use of functionalized radiolabeled nanoplatforms as a noninvasive substitute to standard brachytherapy sources. The limitations of present-day brachytherapy sealed sources are analyzed, while highlighting the advantages of using radiolabeled nanoparticles (NPs) for this purpose. The recent progress in the development of different radiolabeling methods, delivery techniques and nanoparticle internalization mechanisms are discussed. The preclinical studies performed to date are summarized with an emphasis on the current challenges toward the future translation of nanoscale brachytherapy in routine clinical practices.

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