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1.
Trials ; 25(1): 424, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38943204

RESUMO

BACKGROUND: Most patients starting chronic in-center hemodialysis (HD) receive conventional hemodialysis (CHD) with three sessions per week targeting specific biochemical clearance. Observational studies suggest that patients with residual kidney function can safely be treated with incremental prescriptions of HD, starting with less frequent sessions and later adjusting to thrice-weekly HD. This trial aims to show objectively that clinically matched incremental HD (CMIHD) is non-inferior to CHD in eligible patients. METHODS: An unblinded, parallel-group, randomized controlled trial will be conducted across diverse healthcare systems and dialysis organizations in the USA. Adult patients initiating chronic hemodialysis (HD) at participating centers will be screened. Eligibility criteria include receipt of fewer than 18 treatments of HD and residual kidney function defined as kidney urea clearance ≥3.5 mL/min/1.73 m2 and urine output ≥500 mL/24 h. The 1:1 randomization, stratified by site and dialysis vascular access type, assigns patients to either CMIHD (intervention group) or CHD (control group). The CMIHD group will be treated with twice-weekly HD and adjuvant pharmacologic therapy (i.e., oral loop diuretics, sodium bicarbonate, and potassium binders). The CHD group will receive thrice-weekly HD according to usual care. Throughout the study, patients undergo timed urine collection and fill out questionnaires. CMIHD will progress to thrice-weekly HD based on clinical manifestations or changes in residual kidney function. Caregivers of enrolled patients are invited to complete semi-annual questionnaires. The primary outcome is a composite of patients' all-cause death, hospitalizations, or emergency department visits at 2 years. Secondary outcomes include patient- and caregiver-reported outcomes. We aim to enroll 350 patients, which provides ≥85% power to detect an incidence rate ratio (IRR) of 0.9 between CMIHD and CHD with an IRR non-inferiority of 1.20 (α = 0.025, one-tailed test, 20% dropout rate, average of 2.06 years of HD per patient participant), and 150 caregiver participants (of enrolled patients). DISCUSSION: Our proposal challenges the status quo of HD care delivery. Our overarching hypothesis posits that CMIHD is non-inferior to CHD. If successful, the results will positively impact one of the highest-burdened patient populations and their caregivers. TRIAL REGISTRATION: Clinicaltrials.gov NCT05828823. Registered on 25 April 2023.


Assuntos
Estudos Multicêntricos como Assunto , Diálise Renal , Humanos , Resultado do Tratamento , Fatores de Tempo , Pesquisa Comparativa da Efetividade , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos de Equivalência como Asunto , Estados Unidos , Falência Renal Crônica/terapia , Falência Renal Crônica/diagnóstico
2.
J S Afr Vet Assoc ; 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38533817

RESUMO

Reactive oxygen species at supra-physiological levels trigger oxidative stress during cryopreservation, which can be neutralised by incorporating suitable antioxidants into the semen extender medium. This study was intended to explore the effect of asiatic acid (AA) as an antioxidant in semen extender on frozen-thawed sperm quality and in vivo fertility of bull sperm. Semen was collected from Holstein Friesian bulls for 10 consecutive weeks (total ejaculates = 60). Semen was cryopreserved with a Tris citric acid egg yolk-based extender supplemented with 0 (control), 20, 40, 60, and 100 µM AA. The supplementation of the extender with 40 and 60 µM AA improved (p < 0.05) post-thaw motility kinematics, plasma membrane integrity, acrosome integrity, sperm viability, and DNA integrity of bull sperm. Mitochondrial membrane potential was high (p < 0.05) with 60 µM of AA concentration in extender media. The catalase activity in seminal plasma was maintained (p < 0.05) when semen was added with 20, 40, and 60 µM of AA. The in vivo fertility was found to be significantly high with the semen extended with 60 µM AA. Conclusively, this study showed that AA supplementation in semen extender significantly improved sperm motility kinematics and cell integrity, conserved antioxidant enzyme activity, and improved in vivo fertility.

3.
RSC Adv ; 12(51): 33313-33328, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36506480

RESUMO

Understanding the adsorption mechanism of corticosteroids in the lung surfactant requires the knowledge of corticosteroid molecular interactions with lung surfactant monolayer (LSM). We employed coarse-grained molecular dynamics simulation to explore the action of hydrocortisone on an LSM comprised of a phospholipid, cholesterol and surfactant protein. The structural and dynamical morphology of the lung surfactant monolayer at different surface tensions were investigated to assess the monolayer compressibility. The simulations were also conducted at the two extreme ends of breathing cycles: exhalation (0 mN m-1 surface tension) and inhalation (20 mN m-1 surface tension). The impact of surface tension and hydrocortisone concentration on the monolayer compressibility and stability are significant, resulting the monolayer expansion at higher surface tension. However, at low surface tension, the highly compressed monolayer induces monolayer instability in the presence of the drug due to the accumulation of surfactant protein and drug. The constant area per lipid simulation results demonstrate that the surface pressure-area isotherms show a decrease in area-per-lipid with increased drug concentration. The drug-induced expansion causes considerable instability in the monolayer after a specific drug concentration is attained at inhalation breathing condition, whereas, for exhalation breathing, the monolayer gets more compressed, causing the LSM to collapse. The monolayer collapse occurs for inhalation due to the higher drug concentration, whereas for exhalation due to the accumulation of surfactant proteins and drugs. The findings from this study will aid in enhancing the knowledge of molecular interactions of corticosteroid drugs with lung surfactants to treat respiratory diseases.

4.
Biophys J ; 121(18): 3520-3532, 2022 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-35932150

RESUMO

The transient disruption of membranes for the passive permeation of ions or small molecules is a complex process relevant to understanding physiological processes and biotechnology applications. Phenolic compounds are widely studied for their antioxidant and antimicrobial properties, and some of these activities are based on the interactions of the phenolic compound with membranes. Ions are ubiquitous in cells and are known to alter the structure of phospholipid bilayers. Yet, ion-lipid interactions are usually ignored when studying the membrane-altering properties of phenolic compounds. This study aims to assess the role of Ca2+ ions on the membrane-disrupting activity of two phenolic acids and to highlight the role of local changes in lipid packing in forming transient defects or pores. Results from tethered bilayer lipid membrane electrical impedance spectroscopy experiments showed that Ca2+ significantly reduces membrane disruption by caffeic acid methyl ester and caffeic acid. As phenolic acids are known metal chelators, we used UV-vis and fluorescence spectroscopy to exclude the possibility that Ca2+ interferes with membrane disruption by binding to the phenolic compound and subsequently preventing membrane binding. Molecular dynamics simulations showed that Ca2+ but not caffeic acid methyl ester or caffeic acid increases lipid packing in POPC bilayers. The combined data confirm that Ca2+ reduces the membrane-disrupting activity of the phenolic compounds, and that Ca2+-induced changes to lipid packing govern this effect. We discuss our data in the context of ion-induced pores and transient defects and how lipid packing affects membrane disruption by small molecules.


Assuntos
Antioxidantes , Bicamadas Lipídicas , Ácidos Cafeicos , Quelantes , Ésteres , Hidroxibenzoatos , Íons , Bicamadas Lipídicas/química , Fosfolipídeos/química
5.
RSC Adv ; 12(28): 18012-18021, 2022 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-35800307

RESUMO

Ligands like alkanethiol (e.g. dodecanethiol, hexadecanethiol, etc.) and polymers (e.g. poly(vinyl pyrrolidone), polyethylene glycol-thiol) capped to the gold nanoparticles (AuNPs) are widely used in biomedical field as drug carriers and as promising materials for probing and manipulating cellular processes. Ligand functionalised AuNPs are known to interact with the pulmonary surfactant (PS) monolayer once reaching the alveolar region. Therefore, it is crucial to understand the interaction between AuNPs and PS monolayers. Using coarse-grained molecular dynamics simulations, the effect of ligand density, and ligand length have been studied for two classes of ligands on a PS model monolayer consisting of DPPC, POPG, cholesterol and SP-B (mini-peptide). The ligands considered in this study are alkanethiol and polyethylene glycol (PEG) thiol as examples of hydrophobic and hydrophilic ligands, respectively. It was observed that the interaction between AuNPs and PS changes the biophysical properties of PS monolayer in compressed and expanded states. The AuNPs with hydrophilic ligand, can penetrate through the monolayer more easily, while the AuNPs with hydrophobic ligand are embedded in the monolayer and participated in deforming the monolayer structure particularly the monolayer in the compressed state. The bare AuNPs hinder to lower the monolayer surface tension value at the interface, however introducing ligand to the bare AuNPs or increasing the ligand length and density have an impact of lowering of monolayer surface tension to a minor extent. The simulation results guide the design of ligand protected NPs as drug carriers and can identify the nanoparticles' potential side effects on lung surfactant.

6.
Braz J Biol ; 84: e258114, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35649037

RESUMO

The study was aimed to analyse the effects of antibiotic growth promoters (AGPs), Oxytetracycline di-hydrate and Tylosin phosphate on the intestinal microflora in broiler chicken. The AGPs were provided in different concentrations solely or in combinations for 42 days of rearing. Faecal samples were collected from the intestine (duodenum, jejunum and caeca) of broiler chicken on 14th, 28th and 42nd days of trial. Samples were cultured on different selective medium and bacterial identification was performed by different biochemical and molecular diagnostic tools. Results showed a significant effect of AGPs on the growth of pathogenic microorganisms such as Escherichia coli and Clostridium perfringens in the intestine. Interestingly, an impaired growth was observed for both bacterium showing a significant effect (P<0.05) of AGPs on E. coli and C. perfringens on day 14th, 28th, and 42nd. This effect was observed solely and in combination while using AGPs. Data further showed that the effect was more prominent in combination and with an increase concentration of AGPs. Remarkably, no impairment was seen on the growth of L. reuteri at different sites of intestine and duration (14th, 28th, and 42nd days). The results showed that the use of AGPs in diet has no harmful effect on beneficial bacteria, however, an impaired growth was seen on the harmful bacteria. It is suggested that a combination of AGPs (OXY-1.0+TP-0.5) is economical and have no harmful effect on the broiler chicken. The use of AGPs in a recommended dose and for a specific period of time are safe to use in poultry both as growth promoter and for the prevention of diseases.


Assuntos
Microbioma Gastrointestinal , Oxitetraciclina , Animais , Antibacterianos/farmacologia , Bactérias , Galinhas/microbiologia , Clostridium perfringens , Escherichia coli , Oxitetraciclina/farmacologia , Fosfatos , Tilosina/farmacologia
7.
Front Microbiol ; 13: 903146, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35685933

RESUMO

Acquisition of the trace-element molybdenum via the high-affinity ATP-binding cassette permease ModABC is essential for Pseudomonas aeruginosa respiration in anaerobic and microaerophilic environments. This study determined the X-ray crystal structures of the molybdenum-recruiting solute-binding protein ModA from P. aeruginosa PAO1 in the metal-free state and bound to the group 6 metal oxyanions molybdate, tungstate, and chromate. Pseudomonas aeruginosa PAO1 ModA has a non-contiguous dual-hinged bilobal structure with a single metal-binding site positioned between the two domains. Metal binding results in a 22° relative rotation of the two lobes with the oxyanions coordinated by four residues, that contribute six hydrogen bonds, distinct from ModA orthologues that feature an additional oxyanion-binding residue. Analysis of 485 Pseudomonas ModA sequences revealed conservation of the metal-binding residues and ß-sheet structural elements, highlighting their contribution to protein structure and function. Despite the capacity of ModA to bind chromate, deletion of modA did not affect P. aeruginosa PAO1 sensitivity to chromate toxicity nor impact cellular accumulation of chromate. Exposure to sub-inhibitory concentrations of chromate broadly perturbed P. aeruginosa metal homeostasis and, unexpectedly, was associated with an increase in ModA-mediated molybdenum uptake. Elemental analyses of the proteome from anaerobically grown P. aeruginosa revealed that, despite the increase in cellular molybdenum upon chromate exposure, distribution of the metal within the proteome was substantially perturbed. This suggested that molybdoprotein cofactor acquisition may be disrupted, consistent with the potent toxicity of chromate under anaerobic conditions. Collectively, these data reveal a complex relationship between chromate toxicity, molybdenum homeostasis and anaerobic respiration.

8.
Artigo em Inglês | MEDLINE | ID: mdl-35457468

RESUMO

Genetic variants of severe acute respiratory syndrome coronavirus (SARS-CoV-2) have been globally surging and devastating many countries around the world. There are at least eleven reported variants dedicated with inevitably catastrophic consequences. In 2021, the most dominant Delta and Omicron variants were estimated to lead to more severity and deaths than other variants. Furthermore, these variants have some contagious characteristics involving high transmissibility, more severe illness, and an increased mortality rate. All outbreaks caused by the Delta variant have been rapidly skyrocketing in infection cases in communities despite tough restrictions in 2021. Apart from it, the United States, the United Kingdom and other high-rate vaccination rollout countries are still wrestling with this trend because the Delta variant can result in a significant number of breakthrough infections. However, the pandemic has changed since the latest SARS-CoV-2 variant in late 2021 in South Africa, Omicron. The preliminary data suggest that the Omicron variant possesses 100-fold greater than the Delta variant in transmissibility. Therefore, this paper aims to review these characteristics based on the available meta-data and information from the first emergence to recent days. Australia and the five most affected countries, including the United States, India, Brazil, France, as well as the United Kingdom, are selected in order to review the transmissibility, severity and fatality due to Delta and Omicron variants. Finally, the vaccination programs for each country are also reviewed as the main factor in prevention.


Assuntos
COVID-19 , SARS-CoV-2 , COVID-19/epidemiologia , Surtos de Doenças , Humanos , Pandemias , SARS-CoV-2/genética , Estados Unidos/epidemiologia
9.
J Inorg Biochem ; 231: 111787, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35303613

RESUMO

Acinetobacter baumannii is a Gram-negative nosocomial pathogen associated with significant disease. Crucial to the survival and pathogenesis of A. baumannii is the ability to acquire essential micronutrients such as Zn(II). Recruitment of Zn(II) by A. baumannii is mediated, at least in part, by the periplasmic solute-binding protein ZnuA and the ATP-binding cassette transporter ZnuBC. Here, we combined genomic, biochemical, and structural approaches to characterize A. baumannii AB5075_UW ZnuA. Bioinformatic analyses using a diverse collection of A. baumannii genomes determined that ZnuA is highly conserved, with the binding site comprised by three strictly conserved histidine residues. The structure of metal-free ZnuA was determined at 2.1 Å resolution, with molecular dynamics analyses revealing loop α2ß2, which harbors the putative Zn(II)-coordinating residue His41, to be highly mobile in the metal-free state. The contribution of the putative binding site histidine residues to Zn(II) interaction was further probed by mutagenesis. Analysis of ZnuA mutant variants was performed by quantitative metal binding assays, differential scanning fluorimetry, and affinity measurements, which showed that all three histidine residues contributed to Zn(II)-recruitment, albeit to different extents. Collectively, these analyses provide insight into the mechanism of Zn(II)-binding by A. baumannii ZnuA and expand our understanding of the functional diversity of Zn(II)-recruiting proteins.


Assuntos
Acinetobacter baumannii , Transportadores de Cassetes de Ligação de ATP/genética , Acinetobacter baumannii/genética , Proteínas de Bactérias/química , Histidina/química , Modelos Moleculares , Zinco/química
10.
Langmuir ; 38(14): 4188-4199, 2022 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-35344368

RESUMO

The lung surfactant monolayer (LSM) is the main barrier for particles entering the lung, including steroid drugs used to treat lung diseases. The present study combines Langmuir experiments and coarse-grained (CG) molecular dynamics simulations to investigate the concentration-dependent effect of steroid drug prednisolone on the structure and morphology of a model LSM. The surface pressure-area isotherms for the Langmuir monolayers reveal a concentration-dependent decrease in area per lipid (APL). Results from simulations at a fixed surface tension, representing inhalation and exhalation conditions, suggest that at high drug concentrations, prednisolone induces a collapse of the LSM, which is likely caused by the inability of the drug to diffuse into the bilayer. Overall, the monolayer is most susceptible to drug-induced collapse at surface tensions representing exhalation conditions. The presence of cholesterol also exacerbates the instability. The findings of this investigation might be helpful for better understanding the interaction between steroid drug prednisolone and lung surfactants in relation to off-target effects.


Assuntos
Prednisolona , Surfactantes Pulmonares , Pulmão , Prednisolona/farmacologia , Surfactantes Pulmonares/química , Tensão Superficial , Tensoativos
11.
Methods Mol Biol ; 2402: 103-121, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34854039

RESUMO

The lung surfactant monolayer (LSM) is a thin layer of lipids and proteins that forms the air/water interface of the alveoli. The primary function of the LSM is to reduce the surface tension at the air/water interface during breathing. The LSM also forms the main biological barrier for any inhaled particles, including drugs, to treat lung diseases. Elucidating the mechanism by which these drugs bind to and absorb into the LSM requires a molecular-level understanding of any drug-induced changes to the morphology, structure, and phase changes of the LSM.Molecular dynamics simulations have been used extensively to study the structure and dynamics of the LSM. The monolayer is usually simulated in at least two states: the compressed state, mimicking exhalation, and the expanded state, mimicking inhalation. In this chapter, we provide detailed instructions on how to set up, run, and analyze coarse-grained MD simulations to study the concentration-dependent effect of a sterol drug on the LSM, both in the expanded and compressed state.


Assuntos
Surfactantes Pulmonares/química , Pulmão , Simulação de Dinâmica Molecular , Preparações Farmacêuticas , Esteróis , Tensão Superficial , Tensoativos , Água
12.
West J Nurs Res ; 44(9): 863-873, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-34044674

RESUMO

This study compares quality of discharge teaching and care coordination for parents of children with challenging behaviors participating in a nursing implementation project, which used an interactive iPad application, to usual discharge care. Unlike parents in the larger quasi-experimental longitudinal project, parents of children with challenging behaviors receiving the discharge teaching application (n = 14) reported lower mean scores on the quality of discharge teaching scale-delivery subscale (M = 8.2, SD = 3.1) than parents receiving usual care (n = 11) (M = 9.6, SD = 4.7) and lower scores on the Care Transition Measure (M = 2.44, SD = 1.09) than parents receiving usual care (M = 3.02, SD = 0.37), with moderate to large effects (0.554-0.775). The discharge teaching approach was less effective with this subset, suggesting other approaches might be considered for this group of parents. Further study with a larger sample specific to parents of children with challenging behaviors is needed to assess their unique needs and to optimize their discharge experience.


Assuntos
Pais , Alta do Paciente , Criança , Humanos , Pais/educação
13.
J Mol Graph Model ; 111: 108084, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34826717

RESUMO

Mometasone is an investigational anti-inflammatory steroidal drug to treat inflammation via pulmonary administration. For steroid drugs to be effective they need to be adsorbed by lung surfactants, a thin monolayer at the air-water interface in alveoli that reduces surface tension. Information on the molecular-level interactions of the drug with lung surfactants is useful to understand the mechanism of adsorption. In this study, we use coarse-grained molecular dynamics simulation to understand the concentration-dependent effect of mometasone on a lung surfactant monolayer (LSM) composed of lipids and surfactant proteins, under two different breathing conditions (exhalation, at surface tension 0 mNm-1 and inhalation, surface tension 20-25 mNm-1). A series of fixed-APL and fixed-surface tension simulations were used to demonstrate that in the absence of drugs, the model LSM reproduces the surface tensions for the compressed and expanded states, as well as compressibility at different surface tensions. In-depth analysis of simulations of a LSM in the presence of five different drug concentrations shows that mometasone alters the structure and dynamics of the LSM in a concentration-dependent manner. Mometasone induces a collapse in the monolayer that is affected by the surfactant protein and surface tension. Overall, these findings suggest that the surfactant proteins, surface tension and drug concentration are all critical components affecting monolayer stability and drug adsorption. The outcomes of this study may be beneficial for a more in-depth understanding of how mometasone is adsorbed by lung surfactants.


Assuntos
Surfactantes Pulmonares , Pulmão , Furoato de Mometasona , Tensão Superficial , Tensoativos
14.
Phys Chem Chem Phys ; 23(39): 22352-22366, 2021 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-34604899

RESUMO

This study aims to understand the role of specific phenolic-lipid interactions in the membrane-altering properties of phenolic compounds. We combine tethered lipid bilayer (tBLM) electrical impedance spectroscopy (EIS) with all-atom molecular dynamics (MD) simulations to study the membrane interactions of six phenolic compounds: caffeic acid methyl ester, caffeic acid, 3,4 dihydroxybenzoic acid, chlorogenic acid, syringic acid and p-coumaric acid. tBLM/EIS experiments showed that caffeic acid methyl ester, caffeic acid and 3,4 dihydroxybenzoic acid significantly increase the permeability of phospholipid bilayers to Na+ ions. In contrast, chlorogenic acid, syringic acid and p-coumaric acid showed no effect. Experiments with lipids lacking the phosphate group show a significant decrease in the membrane-altering effects indicating that specific phenolic-lipid interactions are critical in altering ion permeability. MD simulations confirm that compounds that alter ion permeability form stable interactions with the phosphate oxygen. In contrast, inactive phenolic compounds are superficially bound to the membrane surface and primarily interact with interfacial water. Our combined results show that compounds with similar structures can have very different effects on ion permeability in membranes. These effects are governed by specific interactions at the water-lipid interface and show no correlation with lipophilicity. Furthermore, none of the compounds alter the overall structure of the phospholipid bilayer as determined by area per lipid and order parameters. Based on data from this study and previous findings, we propose that phenolic compounds can alter membrane ion permeability by causing local changes in lipid packing that subsequently reduce the energy barrier for ion-induced pores.


Assuntos
Bicamadas Lipídicas/química , Fenóis/química , Fosfolipídeos/química , Espectroscopia Dielétrica , Simulação de Dinâmica Molecular , Estrutura Molecular , Permeabilidade
15.
J R Soc Interface ; 18(183): 20210402, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34637640

RESUMO

The lung surfactant monolayer (LSM) forms the main biological barrier for any inhaled particles to enter our bloodstream, including gold nanoparticles (AuNPs) present as air pollutants and under investigation for use in biomedical applications. Understanding the interaction of AuNPs with lung surfactant can assist in understanding how AuNPs enter our lungs. In this study, we use coarse-grained molecular dynamics simulations to investigate the effect of four different shape D AuNPs (spherical, box, icosahedron and rod) on the structure and dynamics of a model LSM, with a particular focus on differences resulting from the shape of the AuNP. Monolayer-AuNP systems were simulated in two different states: the compressed state and the expanded state, representing inhalation and exhalation conditions, respectively. Our results indicate that the compressed state is more affected by the presence of the AuNPs than the expanded state. Our results show that in the compressed state, the AuNPs prevent the monolayer from reaching the close to zero surface tension required for normal exhalation. In the compressed state, all four nanoparticles (NPs) reduce the lipid order parameters and cause a thinning of the monolayer where the particles drag surfactant molecules into the water phase. Comparing the different properties shows no trend concerning which shape has the biggest effect on the monolayer, as shape-dependent effects vary among the different properties. Insights from this study might assist future work of how AuNP shapes affect the LSM during inhalation or exhalation conditions.


Assuntos
Nanopartículas Metálicas , Surfactantes Pulmonares , Ouro , Pulmão , Tensoativos
16.
Artigo em Inglês | MEDLINE | ID: mdl-34207690

RESUMO

A comprehensive understanding of airflow characteristics and particle transport in the human lung can be useful in modelling to inform clinical diagnosis, treatment, and management, including prescription medication and risk assessment for rehabilitation. One of the difficulties in clinical treatment of lung disorders lies in the patients' variable physical lung characteristics caused by age, amongst other factors, such as different lung sizes. A precise understanding of the comparison between different age groups with various flow rates is missing in the literature, and this study aims to analyse the airflow and aerosol transport within the age-specific lung. ANSYS Fluent solver and the large-eddy simulation (LES) model were employed for the numerical simulation. The numerical model was validated with the available literature and the computational results showed airway size-reduction significantly affected airflow and particle transport in the upper airways. This study reports higher deposition at the mouth-throat region for larger diameter particles. The overall deposition efficiency (DE) increased with airway size reduction and flow rate. Lung aging effected the pressure distribution and a higher pressure drop was reported for the aged lung as compared to the younger lung. These findings could inform medical management through individualised simulation of drug-aerosol delivery processes for the patient-specific lung.


Assuntos
Pulmão , Modelos Biológicos , Administração por Inalação , Aerossóis , Fatores Etários , Idoso , Simulação por Computador , Humanos , Tamanho da Partícula
17.
J Phys Chem B ; 125(5): 1392-1401, 2021 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-33529013

RESUMO

Colloidal nanoparticles, such as gold nanoparticles (AuNPs), are promising materials for the delivery of hydrophilic drugs via the pulmonary route. The inhaled nanoparticle drug carriers primarily deposit in lung alveoli and interact with the alveolar surface known as lung surfactants. Therefore, it is vital to understand the interactions of nanocarriers with the surfactant layer. To understand the interactions at the molecular level, here we simulated model lung surfactant monolayers with phospholipid (PL)-wrapped AuNPs at the vacuum-water interface using coarse-grained molecular dynamics simulations. The PL-wrapped AuNPs quickly adsorbed into the surfactant layer, altered the structural properties of the monolayer, and at high concentrations initiated the compressed monolayer to collapse/buckle. Among the surfactant monolayer lipid components, cholesterol adsorbed to the AuNPs preferentially over PL species. The position of the adsorbed PL-AuNPs within the monolayer, and subsequent monolayer perturbation, vary depending on the monolayer phase, monolayer composition, and species of PL used as a ligand. Information provided by these molecular dynamic simulations helps to rationalize why some colloidal nanoparticles work better as nanocarriers than others and aid the design of new ones, to avoid biological toxicity and improve efficacy for pulmonary drug delivery.


Assuntos
Ouro , Nanopartículas Metálicas , Lipídeos , Pulmão , Tensoativos
18.
Phys Chem Chem Phys ; 22(27): 15231-15241, 2020 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-32608403

RESUMO

Lung surfactant (LS) monolayers that continuously expand and compress during breathing cycles, act as the first line barrier for inhaled nanoparticles. It is known that nanoparticles which adsorb to the surface of the surfactant layer facilitate the rearrangement of lipids and peptides at various stages of the breathing cycle. However, the structural mechanisms for this ability of the lipid rearrangement are not yet fully understood. Coarse-grained molecular dynamics simulations are performed to investigate the role of surfactant protein B (SP-B) segments (SP-B1-25) in modulating the biophysical properties of the surfactant monolayer in the presence of polydisperse gold nanoparticles (AuNPs) at different concentrations. Herein, we observe that the AuNPs significantly alter the inherent structural and dynamical properties of the monolayer and its components in three different breathing states. When adsorbed into the monolayer, the AuNPs inhibit the ability of the monolayer to recover its surface tension and other properties. The presence of SP-B1-25 in the monolayer accelerates the diffusion of the monolayer phospholipids, contrarily to the role of AuNPs on phospholipid diffusion. Also, the AuNPs and the peptides in the monolayer significantly increase their agglomeration in the presence of one another. Overall, the simulations predict that the presence of polydisperse AuNPs hampers the stability and biophysical functions of the LS in contrast to the role of the peptide. This study provides a clear view of the hydrophobic peptide role in the LS monolayer at the interface along with the interactions and the translocation of AuNPs that could have a significant impact to assess the NPs inhalation.


Assuntos
Ouro/química , Nanopartículas Metálicas/química , Simulação de Dinâmica Molecular , Proteína B Associada a Surfactante Pulmonar/química , Conformação Proteica
19.
Indian J Palliat Care ; 26(4): 476-478, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33623308

RESUMO

AIM: The poor quality and limited extent of palliative care services are of concern across the globe. To identify and measure patients' symptoms in Nepal, using a cell phone questionnaire platform, the investigators conducted and previously reported a cross-sectional study of Nepali adults. The unreported details of pain and other symptoms in these study data are here considered together with possible explanations and implications for interventions to lessen these symptoms. METHODS: In a "snapshot" cross-sectional study of patients under regular care in three tertiary care Nepalese centers, we questioned 383 patients with incurable cancers using a 15-item cell phone-validated instrument to describe their major current symptoms and their intensities. The distributions of 11 symptom-level scores and the correlations between pain and different symptom scores were determined. RESULTS: Thirty-eight percent of the population (142/383) had maximal pain scores which were in the severe range, and 25% (97/383) had such scores where they were evaluated. Patients reported moderate-to-severe tiredness 48% (183/383), depression 45% (172/383), anxiety 56% (217/383), poor appetite 64% (246/383), sleep quantity 64% (246/383), and sleep quality 64% (247/383). CONCLUSIONS: The significant fractions of patients with severe maximal and at-evaluation pain scores suggest that inadequate recognition and treatment of such symptoms characterized care of these regularly seen patients. The high fractions of patients with mood and sleep disturbances support this reading, suggesting helplessness and hopelessness, all addressable with psychosocial, environmental, and nontoxic, inexpensive pharmacological interventions.

20.
Adv Neonatal Care ; 20(1): E9-E16, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31567181

RESUMO

BACKGROUND: Parents at risk for preterm birth frequently receive prematurity education when the mother is hospitalized for premature labor. Parental ability to learn and consider the information is limited because of the stress of the hospitalization. A promising approach is dissemination of information to at-risk parents before the birth hospitalization. PURPOSE: This article describes formative research used to develop smartphone-based prematurity education app for parents at-risk for preterm birth. METHODS: Stakeholders were parents with a prior preterm birth. Using stakeholder meeting transcripts, constant comparative analysis was used to reflect upon the parental voice. RESULTS: The parents named the app, Preemie Prep for Parents (P3). Parent perspectives revealed desire for information in the following 5 categories. (1) Power in knowledge and control: parents want autonomy when learning information that may influence medical decision-making. (2) Content and framing of information: they desire information from a trusted resource that helps promote prenatal health and provides neonatal intensive care information. (3) Displaying content: parents want personalization, push notifications, photographs displaying fetal development, and easy-to-understand statistics. (4) Providing information without causing harm: they desire non-value-laden information, and they do not support "gamifying" the app to enhance utilization. (5) Decision making: parents want information that would benefit their decision making without assuming that parents have a certain outlook on life or particular values. IMPLICATIONS FOR PRACTICE: These findings support the need for the P3 App to aid in decision making when parents experience preterm birth. IMPLICATIONS FOR RESEARCH: The findings highlight the need to study the effects of smartphone-based prematurity education on medical decision-making.


Assuntos
Cuidado do Lactente/métodos , Doenças do Prematuro/enfermagem , Terapia Intensiva Neonatal/métodos , Aplicativos Móveis , Pais/educação , Cuidado Pré-Natal/métodos , Smartphone , Adulto , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Gravidez , Pesquisa Qualitativa
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