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1.
Cancer Res Commun ; 4(8): 2008-2024, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39007350

RESUMO

Treatment of patients with locally advanced rectal cancer (RC) is based on neoadjuvant chemoradiotherapy followed by surgery. In order to reduce the development of therapy resistance, it is necessary to further improve previous treatment approaches. Recent in vivo experimental studies suggested that the reduction of tumor hypoxia by tumor vessel normalization (TVN), through the inhibition of the glycolytic activator PFKFB3, could significantly improve tumor response to therapy. We have evaluated in vitro and in vivo the effects of the PFKFB3 inhibitor 2E-3-(3-pyridinyl)-1-(4-pyridinyl)-2-propen-1-one (3PO) on cell survival, clonogenicity, migration, invasion, and metabolism using colorectal cancer cells, patient-derived tumor organoid (PDO), and xenograft (PDX). 3PO treatment of colorectal cancer cells increased radiation-induced cell death and reduced cancer cell invasion. Moreover, gene set enrichment analysis shows that 3PO is able to alter the metabolic status of PDOs toward oxidative phosphorylation. Additionally, in vivo neoadjuvant treatment with 3PO induced TVN, alleviated tumor hypoxia, and increased tumor necrosis. Our results support PFKFB3 inhibition as a possible future neoadjuvant addition for patients with RC. SIGNIFICANCE: Novel therapies to better treat colorectal cancer are necessary to improve patient outcomes. Therefore, in this study, we evaluated the combination of a metabolic inhibitor (3PO) and standard radiotherapy in different experimental settings. We have observed that the addition of 3PO increased radiation effects, ultimately improving tumor cell response to therapy.


Assuntos
Fosfofrutoquinase-2 , Neoplasias Retais , Ensaios Antitumorais Modelo de Xenoenxerto , Fosfofrutoquinase-2/antagonistas & inibidores , Fosfofrutoquinase-2/metabolismo , Fosfofrutoquinase-2/genética , Humanos , Animais , Neoplasias Retais/patologia , Neoplasias Retais/radioterapia , Neoplasias Retais/tratamento farmacológico , Neoplasias Retais/metabolismo , Camundongos , Linhagem Celular Tumoral , Piridinas/farmacologia , Piridinas/uso terapêutico , Necrose , Hipóxia Tumoral/efeitos dos fármacos , Terapia Neoadjuvante/métodos , Neovascularização Patológica/tratamento farmacológico
2.
Artigo em Inglês | MEDLINE | ID: mdl-38701495

RESUMO

RATIONALE: There is no consensus on criteria to include in an asthma remission definition in real-life. Factors associated with achieving remission post-biologic-initiation remain poorly understood. OBJECTIVES: To quantify the proportion of adults with severe asthma achieving multi-domain-defined remission post-biologic-initiation and identify pre-biologic characteristics associated with achieving remission which may be used to predict it. METHODS: This was a longitudinal cohort study using data from 23 countries from the International Severe Asthma Registry. Four asthma outcome domains were assessed in the 1-year pre- and post-biologic-initiation. A priori-defined remission cut-offs were: 0 exacerbations/year, no long-term oral corticosteroid (LTOCS), partly/well-controlled asthma, and percent predicted forced expiratory volume in one second ≥80%. Remission was defined using 2 (exacerbations + LTOCS), 3 (+control or +lung function) and 4 of these domains. The association between pre-biologic characteristics and post-biologic remission was assessed by multivariable analysis. MEASUREMENTS AND MAIN RESULTS: 50.2%, 33.5%, 25.8% and 20.3% of patients met criteria for 2, 3 (+control), 3 (+lung function) and 4-domain-remission, respectively. The odds of achieving 4-domain remission decreased by 15% for every additional 10-years asthma duration (odds ratio: 0.85; 95% CI: 0.73, 1.00). The odds of remission increased in those with fewer exacerbations/year, lower LTOCS daily dose, better control and better lung function pre-biologic-initiation. CONCLUSIONS: One in 5 patients achieved 4-domain remission within 1-year of biologic-initiation. Patients with less severe impairment and shorter asthma duration at initiation had a greater chance of achieving remission post-biologic, indicating that biologic treatment should not be delayed if remission is the goal. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).

3.
J Food Sci ; 89(4): 2277-2291, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38488738

RESUMO

Calcium peptide chelates are developed as efficient supplements for preventing calcium deficiency. Spent hen meat (SHM) contains a high percentage of proteins but is generally wasted due to the disadvantages such as hard texture. We chose the underutilized SHM to produce peptides to bind calcium by proteolysis and aimed to investigate chelation between calcium and peptides in hydrolysate for a sustainable purpose. The optimized proteolysis conditions calculated from the result of response surface methodology for two-step hydrolysis were 0.30% (wenzyme/wmeat) for papain with a hydrolysis time of 3.5 h and 0.18% (wenzyme/wmeat) for flavourzyme with a hydrolysis time of 2.8 h. The enzymatic hydrolysate (EH) showed a binding capacity of 63.8 ± 1.8 mg calcium/g protein. Ethanol separation for EH improved the capacity up to a higher value of 68.6 ± 0.6 mg calcium/g protein with a high association constant of 420 M-1 (25°C) indicating high stability. The separated fraction with a higher amount of Glu, Asp, Lys, and Arg had higher calcium-binding capacity, which was related to the number of ─COOH and ─NH2 groups in peptide side chains according to the result from amino acid analysis and Fourier transform infrared spectroscopy. Two-step enzymatic hydrolysis and ethanol separation were an efficient combination to produce peptide mixtures derived from SHM with high calcium-binding capacity. The high percentage of hydrophilic amino acids in the separated fraction was concluded to increase calcium-binding capacity. This work provides foundations for increasing spent hen utilization and developing calcium peptide chelates based on underutilized meat.


Assuntos
Cálcio , Galinhas , Animais , Feminino , Cálcio/metabolismo , Galinhas/metabolismo , Hidrolisados de Proteína/química , Peptídeos/química , Hidrólise , Papaína/química , Aminoácidos , Cálcio da Dieta/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Carne , Etanol
4.
J Asthma Allergy ; 17: 21-32, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38264293

RESUMO

Background: Bronchodilator responsiveness (BDR) in asthma involves both the central and peripheral airways but is primarily relieved with beta-2-agonists and evaluated by spirometry. To date, antimuscarinics can be added as a reliever medication in more severe asthma. We hypothesize that combining both short-acting beta-2 agonist (SABA) and short-acting muscarinic antagonist (SAMA) could also improve the responsiveness in mild-moderate asthma. Therefore, we aimed to compare the direct effects of inhaling SABA alone, SAMA alone or combining both SABA and SAMA on the central and peripheral airways in asthma. Methods: Twenty-three patients with mild-moderate BDR in asthma performed dynamic spirometry and impulse oscillometry before (baseline) and multiple timepoints within an hour after inhalation of SABA (salbutamol), SAMA (ipratropium bromide), or both SABA and SAMA at three different visits. Results: The use of SAMA alone did not show any improvement compared to the use of SABA alone. Inhalation of SABA+SAMA, however, averaged either similar or better BDR than SABA alone in FEV1, MMEF, FVC, R5, R20 and R5-R20. Inhaling SABA+SAMA reached a stable BDR in more patients within 0-10 minutes and also reached the FEV1 (Δ%)>12% faster (3.5 minutes) than inhaling SABA alone (5.1 minutes). Inhaling SABA+SAMA was significantly better than SAMA alone in FEV1 (p = 0.015), MMEF (p = 0.0059) and R20 (p = 0.0049). Using these three variables highlighted a subgroup (30%, including more males) of patients that were more responsive to inhaling SABA+SAMA than SABA alone. Conclusion: Overall, combining SAMA with SABA was faster and more consistent at increasing the lung function than SABA alone or SAMA alone, and the additive effect was best captured by incorporating peripheral-related variables. Therefore, SAMA should be considered as an add-on reliever for mild-moderate patients with BDR in asthma.

5.
Chron Respir Dis ; 20: 14799731231202257, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37800633

RESUMO

This review addresses outstanding questions regarding initial pharmacological management of chronic obstructive pulmonary disease (COPD). Optimizing initial treatment improves clinical outcomes in symptomatic patients, including those with low exacerbation risk. Long-acting muscarinic antagonist/long-acting ß2-agonist (LAMA/LABA) dual therapy improves lung function versus LAMA or LABA monotherapy, although other treatment benefits have been less consistently observed. The benefits of dual bronchodilation in symptomatic patients with COPD at low exacerbation risk, and its duration of efficacy and cost effectiveness in this population, are not yet fully established. Questions remain on the impact of baseline symptom severity, prior treatment, degree of reversibility to bronchodilators, and smoking status on responses to dual bronchodilator treatment. Using evidence from EMAX (NCT03034915), a 6-month trial comparing the LAMA/LABA combination umeclidinium/vilanterol with umeclidinium and salmeterol monotherapy in symptomatic patients with COPD at low exacerbation risk who were inhaled corticosteroid-naïve, we describe how these findings can be applied in primary care.


Assuntos
Agonistas de Receptores Adrenérgicos beta 2 , Doença Pulmonar Obstrutiva Crônica , Humanos , Administração por Inalação , Agonistas de Receptores Adrenérgicos beta 2/uso terapêutico , Broncodilatadores/uso terapêutico , Atenção Primária à Saúde , Ensaios Clínicos como Assunto
6.
Food Res Int ; 164: 112415, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36737996

RESUMO

Calcium bioaccessibility depends on the amount of soluble calcium under intestinal digestion. The changes in calcium during in vitro static digestion of α-lactalbumin and ß-lactoglobulin in presence of calcium chloride (0 mM, 20 mM and 50 mM) were followed by combining electrochemical determination of free calcium with the determination of soluble calcium by inductively coupled plasma optical emission spectroscopy. α-Lactalbumin and, more evident, ß-lactoglobulin were found to increase calcium bioaccessibility with increasing intestinal digestion time by around 5% and 10%, respectively, due to the complex binding of calcium to peptides formed from protein hydrolysis by gastrointestinal enzymes. In vitro digested samples of ß-lactoglobulin in presence of CaCl2 had nearly twice as much complex bound calcium as α-lactalbumin samples. The calcium bioaccessibility decreased significantly with the increasing concentration of added calcium chloride, although the amount of calcium chloride had little effect on the extension of digestion of α-lactalbumin and ß-lactoglobulin. Simulated digestion fluids were found to have a negative effect on calcium bioaccessibility, especially the presence of hydrogen phosphate, and the amount of precipitated calcium increased significantly with increasing amount of added calcium chloride. Based on analysis and visualization by sequences of the peptides formed during digestion of α-lactalbumin and ß-lactoglobulin, it was observed that peptides containing aspartic acid and glutamic acid acting as calcium chelators, may prevent precipitation of calcium in the intestines and increase calcium bioaccessibility. These results provide knowledge for the design of new dairy based functional foods to prevent calcium deficiency.


Assuntos
Lactalbumina , Lactoglobulinas , Lactalbumina/química , Lactoglobulinas/química , Cálcio , Cloreto de Cálcio , Cálcio da Dieta , Peptídeos , Digestão
8.
Food Res Int ; 159: 111625, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35940812

RESUMO

Aspartate (Asp) mononegative ion binds calcium through both carboxylates in contrast to binding through only the side chain carboxylate for mononegative glutamate (Glu), as shown by density functional theory (DFT) calculations. A stronger binding was confirmed electrochemically for Asp compared to Glu. From temperature dependence of binding constant, 15-37 °C investigated for aqueous 0.16 M NaCl, a more negative ΔH0 of - 21 kJ·mol-1 was found for Glu compared to ΔH0 =  -17 kJ·mol-1 for Asp, a difference confirmed by DFT calculations and qualitatively also by isothermal titration calorimetry. The stronger binding of calcium to Asp (Kass,c = 5.3 M-1 at 37 °C) compared to Glu (Kass,c = 3.6 M-1 at 37 °C) despite the less negative enthalpy of binding is accordingly an entropy effect due to ring formation in the complex for Asp.


Assuntos
Ácido Aspártico , Cálcio , Cálcio/metabolismo , Cálcio da Dieta , Ácido Glutâmico , Temperatura , Termodinâmica
9.
Respir Med ; 200: 106918, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35803172

RESUMO

Early MAXimisation of bronchodilation for improving COPD stability (EMAX) was a large, multicentre, multi-national, randomised, double-blind, 24-week trial. EMAX evaluated the efficacy and safety of dual bronchodilator therapy with umeclidinium bromide (UMEC)/vilanterol (VI) versus monotherapy with either UMEC or salmeterol (SAL) in symptomatic patients with chronic obstructive pulmonary disease (COPD) at low exacerbation risk who were not taking concomitant inhaled corticosteroid (ICS). EMAX generated evidence covering a wide range of patient-centred endpoints in COPD in addition to measures of lung function, clinical deterioration and safety. In addition, prospective and post hoc secondary analyses have generated clinically valuable information regarding the effects of baseline patient characteristics on treatment outcomes. Importantly, as concomitant ICS use was not permitted in this study, EMAX compared dual long-acting muscarinic antagonist (LAMA)/long-acting ß2-agonist (LABA) therapy with LAMA or LABA monotherapy without potential confounding due to concurrent ICS use or withdrawal. EMAX demonstrated beneficial treatment effects of UMEC/VI over UMEC or SAL monotherapy as maintenance treatment across a range of different patient characteristics, with no forfeit in safety. Thus, the trial provided novel insights into the role of LAMA/LABA versus LABA and LAMA monotherapies as maintenance therapy for patients with symptomatic COPD at low risk of exacerbations. This article will explore the clinical implications of the main findings to date of the EMAX trial and consider the key learnings this trial offers for future trial design in COPD.


Assuntos
Broncodilatadores , Doença Pulmonar Obstrutiva Crônica , Administração por Inalação , Agonistas de Receptores Adrenérgicos beta 2 , Clorobenzenos , Combinação de Medicamentos , Combinação Fluticasona-Salmeterol , Humanos , Estudos Multicêntricos como Assunto , Antagonistas Muscarínicos , Estudos Prospectivos , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Quinuclidinas/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Xinafoato de Salmeterol/uso terapêutico , Resultado do Tratamento
10.
Front Allergy ; 3: 889221, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35769567

RESUMO

Background: Type 2 inflammation underlies the chronicity of disease in subgroups of patients with asthma, chronic rhinosinusitis with nasal polyps (CRSwNP) and atopic dermatitis (AD), that often co-exist. Although several studies have investigated the unmet needs of asthma, AD and CRSwNP as such, little is known about the similarities and differences in experiences and perspectives of the current management of patients with comorbid Type 2 inflammatory diseases. Aims: To improve insight into the common and organ-specific needs of patients with Type 2 inflammation and comorbidities, allowing the formulation of recommendations to better address these needs in the future. Methodology: This qualitative study was conducted between July 2021 and December 2021 using semi-structured face-to-face or telephone interviews with patients suffering from year-long severe chronic Type 2 inflammation and at least one co-morbid inflammatory condition. Seven participating academic centers in Europe interviewed asthma (Copenhagen and Leuven), CRSwNP (London, Amsterdam and Crete) and/or AD (Oldenburg and Zurich) patients on patient characteristics, disease severity, shortcomings of current care pathways and suggestions for improvement of care. Transcripts were analyzed using an inductive thematic analysis approach. Results: Eighty-one patients with severe Type 2 inflammation and comorbidities were interviewed. Similar needs were recognized by patients with Type 2 inflammation, with both a lack of coordination in care and a lack of a real cure reported as being most frustrating. However, several needs are specific to asthma, CRSwNP and AD. Suggestions for improvement of care were generic across diseases, such as the implementation of a multidisciplinary approach, the improved facilitation of access to better treatments, the increase of general awareness on disease burden, and better educational programs for healthcare providers and patients. Of note, patients with CRSwNP also stated the need for alternatives to sinus surgery, whereas patients with asthma requested better medical care to prevent exacerbations and patients with AD would warmly welcome the reimbursement of emollients. Conclusion: Patients with asthma, CRSwNP and AD have shared unmet needs that need to be addressed by physicians, the academic community and health policy makers. This survey provides unique recommendations made by patients for the implementation of better care.

11.
ACS Omega ; 7(23): 19521-19534, 2022 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-35721975

RESUMO

The interactions of luteolin (Lut) with bovine serum albumin (BSA) mediated by Cu(II) were investigated by spectroscopic, calorimetric, and molecular dynamic (MD) methods. Fluorescence studies showed that the binding of Lut to BSA was significantly enhanced by Cu(II) coordination with the number of binding sites and binding constant increasing from n = 1 and K a = 3.2 × 105 L·mol-1 for Lut to n = 2 and K a = 7.1 × 105 L·mol-1 for a 1:1 Cu(II)-luteolin complex, in agreement with the results from isothermal titration calorimetry (ITC). Site-specific experiments with warfarin and ibuprofen and MD confirmed that two binding sites of BSA were sequentially occupied by two Cu(II)-luteolin complexes. Cu(II) coordination increased the antioxidant activity of luteolin by 60% in the inhibition of carbonyl formation from the oxidation of amino groups in the side chain of BSA induced by the peroxyl radical ROO•; however, it counteracted the antioxidant effects of luteolin and played pro-oxidative roles in BSA aggregation induced by •OH.

12.
Food Res Int ; 154: 110981, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35337555

RESUMO

The kinetics of binding of calcium ions in molar excess to individual caseins and casein ingredients was studied in pH 6.4 aqueous solutions using stopped-flow absorption spectroscopy. An initial second-order reaction, faster for ß-casein than for αs-casein due to lower energy of activation (ΔEa1,ß = 8.2 kJ∙mol-1; ΔEa1,α = 18.1 kJ∙mol-1, respectively), is followed by a slower first-order reaction with similar energies of activation (ΔEa2,ß = 25.3 kJ∙mol-1 and ΔEa2,α = 20.7 kJ∙mol-1) as determined from temperature dependence of rate between 25 °C and 50 °C. Sodium caseinate reacts faster with calcium than both αs-casein and ß-casein in the first reaction of the two consecutive reactions, while the rate of the second falls between αs-casein and ß-casein. Global spectral analysis showed the UV-visible spectra of the reaction intermediates of the caseins to be more similar to the final products than to the initial casein reactants. Dynamic and static light scattering indicated decreasing particle sizes and increasing particle surface upon calcium-binding most significantly at low temperatures. The calcium binding to casein was found endothermic by isothermal titration calorimetry. Calcium binding seems to be controlled by enthalpy/entropy compensation corresponding to an isoequilibrium temperature of 38 °C in agreement with binding of calcium to o-phosphoserine rather than to aspartate or glutamate side chains of the caseins. Binding capacity and affinity for calcium to αs-casein and sodium caseinate both increased with increasing temperature in agreement with the endothermic nature of the binding. Decreasing enthalpy of binding for each calcium indicating a decrease in heat capacity of the caseins upon calcium-binding. The small difference between binding enthalpy and energy of activation for association of calcium to αs-casein lead to the conclusion that calcium dissociation goes through an early transition state. The rate of calcium dissociation hardly depends on temperature also explaining why calcium binding to caseins is important for calcium bioaccessibility.


Assuntos
Cálcio , Caseínas , Caseínas/química , Micelas , Temperatura , Termodinâmica
13.
Biophys Chem ; 285: 106807, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35349930

RESUMO

The present work is intended to investigate the morphological instability of lipid membrane induced by peroxyl radical (ROO•) and the underlying mechanism. To this end, the giant unilamellar vesicle (GUV) made from phosphatidylcholine was employed as a membrane model, and the azo compounds 2,2'-azobis(2,4-dimethylvaleronitrile) (AMVN) and 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) were used as the precursors of ROO•. Upon mild pyrolysis, the GUV immobilized in agarose gel was followed by conventional optical microscopy in real time, and the morphological variation was quantified by the image heterogeneity, perimeter and area all as a function of time for up to an hour. Lipid oxidation initiated from lipid phase with AMVN and from aqueous phase with AAPH led to different types of morphological changes, i.e. membrane coarsening and vesicle deformation/budding, respectively. Based on the compositional analysis of lipid oxidation products, we propose that ROO• as the primary radical initiator is responsible for the morphological changes of the GUV-AMVN while both ROO• and RO• are responsible for the morphological changes of the GUV-AAPH system. Lipophilic ß-carotene and amphipathic plant phenols as antioxidants are found to be able to stabilize the membrane integrity effectively, in corroboration with the proposed mechanisms for membrane destruction.


Assuntos
Amidinas , Lipossomas Unilamelares , Amidinas/farmacologia , Nitrilas/farmacologia , Oxirredução , Peróxidos , Fosfatidilcolinas/química
14.
Food Chem ; 374: 131701, 2022 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-34902813

RESUMO

Uptake of calcium from food depends on solubility of calcium salts in the intestines, and precipitation of calcium phosphates decreases bioaccessibility of food calcium. Citrate as a high affinity complex binder for calcium was found spontaneously to create strongly supersaturated solutions by rapid dissolution of calcium hydrogen phosphate characterized by short lag phases for precipitation. Gluconate with weaker affinity for calcium binding showed longer lag phases for precipitation from supersaturated solutions. For citrate/gluconate combinations, the highest degree of supersaturation with longest lag phases for precipitation were found by trial-and-error experiments for a citrate/gluconate ratio of 1:10 for dissolution of calcium hydrogen phosphate resulting in supersaturation factors around three and without precipitation for more than a month. The aim of the present study was to provide a physicochemical explanation of this robust supersaturation. Calcium speciation based on electrochemical calcium activity measurement identified a low [Ca2+]·[HCitr2-] product as critical for supersaturation.


Assuntos
Ácido Cítrico , Alimento Funcional , Cálcio , Fosfatos de Cálcio , Citratos , Gluconatos , Solubilidade
15.
Food Chem ; 367: 130674, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34343801

RESUMO

Strontium chloride added to aqueous suspensions of metastable calcium citrate tetrahydrate increased calcium ion activity measured electrochemically without transition of metastable tetrahydrate to stable calcium citrate hexahydrate as shown by DSC. Calcium activity increase was explained by lower solubility of strontium citrate pentahydrate formed (8.9 × 10-4 M at 25 °C) increasing with temperature compared to calcium citrate tetrahydrate (1.6 × 10-3 M) decreasing with temperature. Strontium binding to citrate was found endothermic, ΔH0 = 45 kJ∙mol-1 at 25 °C, while calcium binding shows variation from ΔH0 = 94 kJ∙mol-1 at 10 °C becoming exothermic above physiological temperature with ΔH0 = -9 kJ∙mol-1 at 45 °C as determined from temperature and concentration variation in electric conductivity. These differences in solution thermodynamics and pH effect on complex formation between calcium and strontium citrate are discussed in relation to biomineralization.


Assuntos
Citrato de Cálcio , Cálcio , Solubilidade , Estrôncio , Termodinâmica
16.
Food Res Int ; 149: 110714, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34600648

RESUMO

Calcium binding to peptides formed by hydrolysis of whey proteins during digestion is important for calcium uptake in the intestines and affects the antioxidant function of the peptides. For the two dipeptides, Gly-Tyr and Tyr-Gly, potential hydrolysis products of α-lactalbumin, calcium binding to the three forms of each dipeptide in acid-base equilibrium at intestinal pH was determined electrochemically and compared to binding to tyrosine for aqueous 0.16 M NaCl for 5 < pH < 9 at 15 °C, 25 °C, and 37 °C. At milk pH at 25 °C, binding of calcium to the zwitterion of GlyTyr dominates, with an association constant Kass2 = 22 M-1 with ΔH0 = -46 kJ·mol-1, while binding to the mononegative TyrGly dominates for TyrGly with Kass3 = 32 M-1 and ΔH0 = -38 kJ·mol-1. At intestinal conditions, pH = 7 and 37 °C, binding of calcium has similar affinity for GlyTyr and TyrGly, while at higher pH and lower temperature, GlyTyr binds stronger. Density Functional Theory calculations confirmed a stronger binding to the zwitterion of GlyTyr than of TyrGly and an increasing affinity with increasing pH for both. Calcium binding to the acid/base forms of the dipeptides is at neutral pH strongly exothermic with ΔH0 becoming less negative at higher pH, and a linear enthalpy-entropy compensation (r2 = 0.99) results in comparable binding important for calcium bioavailability along the changing distribution among acid-base forms. Calcium binding decreases radical scavenging rate and antioxidative activity of both dipeptides.


Assuntos
Cálcio , Lactalbumina , Dipeptídeos , Entropia , Glicina , Hidrólise , Tirosina
17.
Respir Res ; 22(1): 279, 2021 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-34711232

RESUMO

BACKGROUND: In patients with chronic obstructive pulmonary disease (COPD), the relationship between short-term bronchodilator reversibility and longer-term response to bronchodilators is unclear. Here, we investigated whether the efficacy of long-acting bronchodilators is associated with reversibility of airflow limitation in patients with COPD with a low exacerbation risk not receiving inhaled corticosteroids. METHODS: The double-blind, double-dummy EMAX trial randomised patients to umeclidinium/vilanterol 62.5/25 µg once daily, umeclidinium 62.5 µg once daily, or salmeterol 50 µg twice daily. Bronchodilator reversibility to salbutamol was measured once at screening and defined as an increase in forced expiratory volume in 1 s (FEV1) of ≥ 12% and ≥ 200 mL 10-30 min post salbutamol. Post hoc, fractional polynomial (FP) modelling was conducted using the degree of reversibility (mL) at screening as a continuous variable to investigate its relationship to mean change from baseline in trough FEV1 and self-administered computerised-Transition Dyspnoea Index (SAC-TDI) at Week 24, Evaluating Respiratory Symptoms-COPD (E-RS) at Weeks 21-24, and rescue medication use (puffs/day) over Weeks 1-24. Analyses were conducted across the full range of reversibility (-850-896 mL); however, results are presented for the range -100-400 mL because there were few participants with values outside this range. RESULTS: The mean (standard deviation) reversibility was 130 mL (156) and the median was 113 mL; 625/2425 (26%) patients were reversible. There was a trend towards greater improvements in trough FEV1, SAC-TDI, E-RS and rescue medication use with umeclidinium/vilanterol with higher reversibility. Improvements in trough FEV1 and reductions in rescue medication use were greater with umeclidinium/vilanterol compared with either monotherapy across the range of reversibility. Greater improvements in SAC-TDI and E-RS total scores were observed with umeclidinium/vilanterol versus monotherapy in the middle of the reversibility range. CONCLUSIONS: FP analyses suggest that patients with higher levels of reversibility have greater improvements in lung function and symptoms in response to bronchodilators. Improvements in lung function and rescue medication use were greater with umeclidinium/vilanterol versus monotherapy across the full range of reversibility, suggesting that the dual bronchodilator umeclidinium/vilanterol may be an appropriate treatment for patients with symptomatic COPD, regardless of their level of reversibility.


Assuntos
Agonistas de Receptores Adrenérgicos beta 2/administração & dosagem , Álcoois Benzílicos/administração & dosagem , Broncodilatadores/administração & dosagem , Clorobenzenos/administração & dosagem , Pulmão/efeitos dos fármacos , Antagonistas Muscarínicos/administração & dosagem , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Quinuclidinas/administração & dosagem , Agonistas de Receptores Adrenérgicos beta 2/efeitos adversos , Idoso , Álcoois Benzílicos/efeitos adversos , Broncodilatadores/efeitos adversos , Clorobenzenos/efeitos adversos , Método Duplo-Cego , Combinação de Medicamentos , Feminino , Volume Expiratório Forçado , Humanos , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Antagonistas Muscarínicos/efeitos adversos , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Quinuclidinas/efeitos adversos , Recuperação de Função Fisiológica , Fatores de Tempo , Resultado do Tratamento
18.
Adv Ther ; 38(9): 4815-4835, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34347255

RESUMO

INTRODUCTION: Smoking may reduce the efficacy of inhaled corticosteroids (ICS) in patients with chronic obstructive pulmonary disease (COPD), but its impact on bronchodilator efficacy is unclear. This analysis of the EMAX trial explored efficacy and safety of dual- versus mono-bronchodilator therapy in current or former smokers with COPD. METHODS: The 24-week EMAX trial evaluated lung function, symptoms, health status, exacerbations, clinically important deterioration, and safety with umeclidinium/vilanterol, umeclidinium, and salmeterol in symptomatic patients at low exacerbation risk who were not receiving ICS. Current and former smoker subgroups were defined by smoking status at screening. RESULTS: The analysis included 1203 (50%) current smokers and 1221 (50%) former smokers. Both subgroups demonstrated greater improvements from baseline in trough FEV1 at week 24 (primary endpoint) with umeclidinium/vilanterol versus umeclidinium (least squares [LS] mean difference, mL [95% CI]; current: 84 [50, 117]; former: 49 [18, 80]) and salmeterol (current: 165 [132, 198]; former: 117 [86, 148]) and larger reductions in rescue medication inhalations/day over 24 weeks versus umeclidinium (LS mean difference [95% CI]; current: - 0.42 [- 0.63, - 0.20]; former: - 0.25 - 0.44, - 0.05]) and salmeterol (current: - 0.28 [- 0.49, - 0.06]; former: - 0.29 [- 0.49, - 0.09]). Umeclidinium/vilanterol increased the odds (odds ratio [95% CI]) of clinically significant improvement at week 24 in Transition Dyspnea Index versus umeclidinium (current: 1.54 [1.16, 2.06]; former: 1.32 [0.99, 1.75]) and salmeterol (current: 1.37 (1.03, 1.82]; former: 1.60 [1.20, 2.13]) and Evaluating Respiratory Symptoms-COPD versus umeclidinium (current: 1.54 [1.13, 2.09]; former: 1.50 [1.11, 2.04]) and salmeterol (current: 1.53 [1.13, 2.08]; former: 1.53 [1.12, 2.08]). All treatments were well tolerated in both subgroups. CONCLUSIONS: In current and former smokers, umeclidinium/vilanterol provided greater improvements in lung function and symptoms versus umeclidinium and salmeterol, supporting consideration of dual-bronchodilator therapy in symptomatic patients with COPD regardless of their smoking status.


Patients with chronic obstructive pulmonary disease (COPD) often require daily medication to control their COPD. Many patients with COPD are smokers, and smoking is one of the most common causes of COPD. This means that it is important to find out whether COPD medications are effective in both smokers and nonsmokers. We analyzed data from a clinical trial (EMAX) that investigated the use of a combination of two bronchodilators, which are inhaled medications that help to open the airways. We compared umeclidinium/vilanterol, a dual-bronchodilator combination, with a single bronchodilator (either umeclidinium or salmeterol) over 6 months. We found that both current and former smokers who were treated with umeclidinium/vilanterol had larger improvements in lung function than those receiving umeclidinium or salmeterol. Current or former smokers who were treated with umeclidinium/vilanterol used their reliever inhaler less than those treated with umeclidinium or salmeterol. Patients treated with umeclidinium/vilanterol were generally less likely to experience disease worsening compared with umeclidinium or salmeterol if they were former smokers, or compared with salmeterol if they were current smokers. Our findings suggest that umeclidinium/vilanterol may be more effective than a single bronchodilator for daily treatment of patients with COPD who are current or former smokers. Physicians should consider prescribing a combination of two bronchodilators to patients who have symptoms, whether or not they currently smoke, as well as encouraging smoking cessation for all patients.


Assuntos
Doença Pulmonar Obstrutiva Crônica , Fumantes , Administração por Inalação , Álcoois Benzílicos , Broncodilatadores/uso terapêutico , Clorobenzenos/uso terapêutico , Método Duplo-Cego , Combinação de Medicamentos , Volume Expiratório Forçado , Humanos , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Quinuclidinas/uso terapêutico , Resultado do Tratamento
19.
Biophys Chem ; 275: 106624, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34051444

RESUMO

Singlet oxygen (1O2) formed through photosensitization may initiate oxidative destruction of biomembranes, however, the influence from the spatial organization of photosensitizers (PS) relative to membranes remains unclear. To clarify this issue, we loaded riboflavin 5'-(dihydrogen phosphate) monosodium (FMN-Na) as a hydrophilic PS into the lumen of halloysite nanotubes (HNTs), and attached the nanoassemblies (FMN-Na@HNTs), via Pickering effects, to the outer surfaces of giant unilamellar vesicles (GUVs) of phospholipids. We also prepared GUVs dopped with lumiflavin (LF) as a lipophilic PS having a 1O2 quantum yield comparable to FMN-Na. FMN-Na capsulated in HNT was characterized by a longer triplet excited state lifetime (12.1 µs) compared to FMN-Na free in solution (7.5 µs), and FMN-Na in both forms efficiently generated 1O2 upon illumination. The spatio-effects of PS on the photosensitized morphological changes of membranes were studied using conventional optical microscopy by monitoring GUV morphological changes. Upon light exposure (400-440 nm), the GUVs attached with FMN-Na@HNT merely experienced membrane deformation starting from the original spherical shape, ascribed to Type II photosensitization with 1O2 as oxidant. In contrast, photooxidation of LF dopped GUVs mainly led to membrane coarsening and budding assigned to Type I photosensitization. The spatial effects of PS on photosensitized morphological changes were related to the different lipid oxidation products generated through Type I and Type II photosensitized lipid oxidation.


Assuntos
Lipossomas Unilamelares , Oxirredução , Fármacos Fotossensibilizantes , Oxigênio Singlete
20.
Food Res Int ; 140: 109867, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33648185

RESUMO

Calcium citrate tetrahydrate (CCT) and hexahydrate (CCH) precipitates from aqueous solutions of CaCl2 and sodium citrate above and below the transition temperature of 52 °C, respectively. The CCT, the dihydrate (CCD) and anhydrate (CCA) as obtained by a stepwise dehydration of solid CCH have enthalpy of dehydration of ΔH0CCH to CCT = 43.6, ΔH0CCT to CCD = 43.8, and ΔH0CCD to CCA = 88.1 kJ∙mol-1 as measured by DSC. WAXS measurements demonstrate a stepwise decrease in unit cell size upon dehydration, and a stronger binding of the two first water compared to additional. The increasing negative enthalpy of dissolution, as calculated from the temperature dependence of solubility (10-90 °C), +21 kJ∙mol-1 (CCH), -20 kJ∙mol-1 (CCT), -22 kJ∙mol-1 (CCD), and -40 kJ∙mol-1 (CCA) shows along the series of hydrates with increasing solubility, enthalpy-entropy compensation with an isoequilibrium temperature of 49 °C. Conversion of CCD and CCA in aqueous solutions yields the more soluble CCT, not the stable CCH in agreement with Ostwald's stage law, increasing calcium bioaccessibility under physiological conditions in intestines.


Assuntos
Citrato de Cálcio , Cálcio , Solubilidade , Termodinâmica , Água
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