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Group B Streptococcus (Streptococcus agalactiae; GBS) is a leading cause of neonatal sepsis worldwide. As a pathobiont of the intestinal tract, it is capable of translocating across barriers leading to invasive disease. Neonatal susceptibility to invasive disease stems from immature intestinal barriers. GBS intestinal colonization induces major transcriptomic changes in the intestinal epithelium related to barrier function. Butyrate, a microbial metabolite produced by fermentation of dietary fiber, bolsters intestinal barrier function against enteric pathogens, and these effects can be transferred in utero via the placenta to the developing fetus. Our aim was to determine if butyrate mitigates GBS disruption of intestinal barriers. We used human intestinal epithelial cell (IEC) lines to evaluate the impact of butyrate on GBS-induced cell death and GBS adhesion and invasion. IECs and human fetal tissue-derived enteroids were used to evaluate monolayer permeability. We evaluated the impact of maternal butyrate treatment (mButyrate) using our established mouse model of neonatal GBS intestinal colonization and late-onset sepsis. We found that butyrate reduces GBS-induced cell death, GBS invasion, monolayer permeability, and translocation in vitro. In mice, mButyrate decreases GBS intestinal burden in offspring. Our results demonstrate the importance of bacterial metabolites, such as butyrate, in their potential to bolster epithelial barrier function and mitigate neonatal sepsis risk.IMPORTANCEGroup B Streptococcus (GBS) is a leading cause of neonatal morbidity and mortality. It is a commensal of the intestines that can translocate across barriers leading to sepsis in vulnerable newborns. With the rise in antibiotic-resistant strains and no licensed vaccine, there is an urgent need for preventative strategies. Butyrate, a short-chain fatty acid metabolized in the gut, enhances barrier function against pathogens. Importantly, butyrate is transferred in utero, conferring these benefits to infants. Here, we demonstrate that butyrate reduces GBS colonization and epithelial invasion. These effects were not microbiome-driven, suggesting butyrate directly impacts epithelial barrier function. Our results highlight the potential impact of maternal dietary metabolites, like butyrate, as a strategy to mitigate neonatal sepsis risk.
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BACKGROUND: A foam layer makes an essential contribution to the quality of cappuccino-style drinks. Poor foaming of milk occurs quite often, however, especially in summer. The reasons for this are still unknown. Although a substantial number of studies on the foaming process of milk have been reported, these studies have been laboratory based and have used laboratory or pilot-scale equipment to simulate the processing conditions of a dairy processing factory. This study collected about 40 different samples across different processing stages in a dairy factory over two seasons (two batches per season) and investigated their composition and physical and foaming properties by mechanical mixing and steam injection. RESULTS: The results showed that milk samples collected in summer had a significantly higher content of fat, free fatty acids, and Ca2+ ions, and larger particle sizes but a markedly lower concentration of protein and solid non-fat, and surface tension than the samples collected in spring. These differences provided spring milk with a higher steam injection foamability than summer milk. However, steam injection foam stability, and mechanical mixing foamability and foam stability were not affected by seasonal factors. Milk samples collected in different batches within a season were almost identical with regard to the properties that were investigated. CONCLUSION: The variations in composition and physical properties of milk collected between two seasons could be the reasons for their difference in foamability but not for foam stability. Processes such as standardization, homogenization, and pasteurization improved markedly the foaming properties of milk. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Leite , Vapor , Animais , Leite/química , Estações do Ano , PasteurizaçãoRESUMO
Cyclotides are plant peptides characterized with a head-to-tail cyclized backbone and three interlocking disulfide bonds, known as a cyclic cysteine knot. Despite the variations in cyclotides peptide sequences, this core structure is conserved, underlying their most useful feature: stability against thermal and chemical breakdown. Cyclotides are the only natural peptides known to date that are orally bioavailable and able to cross cell membranes. Cyclotides also display bioactivities that have been exploited and expanded to develop as potential therapeutic reagents for a wide range of conditions (e.g., HIV, inflammatory conditions, multiple sclerosis, etc.). As such, in vitro production of cyclotides is of the utmost importance since it could assist further research on this peptide class, specifically the structure-activity relationship and its mechanism of action. The information obtained could be utilized to assist drug development and optimization. Here, we discuss several strategies for the synthesis of cyclotides using both chemical and biological routes.
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Ciclotídeos , Ciclotídeos/farmacologia , Ciclotídeos/uso terapêutico , Ciclotídeos/química , Sequência de Aminoácidos , Plantas/metabolismo , Cisteína , Relação Estrutura-AtividadeRESUMO
Natural bioactive compounds (BCs) are types of chemicals found in plants and certain foods that promote good health, however they are sensitive to processing and environmental conditions. Microencapsulation by spray drying is a widely used and cost-effective approach to create a coating layer to surround and protect BCs and control their release, enabling the production of high functional products/ingredients with extended shelf life. In this process, wall materials determine protection efficiency, and physical properties, bioavailability, and storage stability of microencapsulated products. Therefore, an understanding of physicochemical properties of wall materials is essential for the successful and effective spray-dried microencapsulation process. Typically, polysaccharide-based wall materials are generated from more sustainable sources and have a wider range of physicochemical properties and applications compared to their protein-based counterparts. In this review, we highlight the essential physicochemical properties of polysaccharide-based wall materials for spray-dried microencapsulation of BCs including solubility, thermal stability, and emulsifying properties, rheological and film forming properties. We provide further insight into possibilities for the chemical structure modification of native wall materials and their controlled release behaviors. Finally, we summarize the most recent studies involving polysaccharide biopolymers as wall materials and/or emulsifiers in spray-dried microencapsulation of BCs.
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Extratos Vegetais , Polissacarídeos , Polissacarídeos/química , Extratos Vegetais/química , Alimentos , SolubilidadeRESUMO
Immune cell therapy has been incorporated into cancer therapy over the past few years. Chimeric antigen receptor T cells (Car-T cells) transplantation is a novel and promising therapy for cancer treatment and introduces a new age of immune cell therapy. However, the expensive nature of genetic modification procedures limits the accessibility of Car-T cells for cancer treatment. Cytokine-induced killer cells (CIKs) can kill the target cells in an MHC-non-restricted manner; these cells can be developed to "off-the-shelf" immune cell products for cancer treatment. However, the anti-tumor potency of freshly thawed CIKs is not well documented. This study aimed to fill this gap, evaluating the anti-tumor potency of freshly thawed CIKs compared to that of freshly cultured CIKs. CIKs were produced from the human umbilical cord blood in accordance with published protocols. CIKs were cryopreserved in xeno-free cryomedium that contains 5% DMSO, 10% human serum in phosphate buffer saline at - 86 °C. These cells were thawed and immediately utilized in assays (called freshly thawed CIKs) with freshly cultured cells are control. The expression of the surface markers of CIKs, cytokine production, and in vitro anti-tumor cytotoxic cells of freshly thawed CIKs were evaluated and compared to freshly cultured CIKs. Additionally, the freshly thawed CIKs were injected into the breast of tumor-bearing mice to assess the anti-tumor potency in vivo. The results obtained in freshly thawed CIKs and freshly cultured CIKs demonstrated that the expression of CD3, and CD56 were comparable in both cases. The production of TNF-α, IFN-γ, and IL-10 was slightly reduced in freshly thawed cells compared to the freshly cultured cells. The in vitro lysis toward MCF-7 cancer cells was similar between freshly thawed and freshly cultured CIKs. Moreover, the freshly thawed CIKs displayed anti-breast tumor activity in the breast tumor-bearing mice. The volume of tumors significantly reduced in the mice grafted with freshly thawed CIKs while, conversely, the tumor volume in mice of the placebo group gradually increased. This study substantiated that freshly thawed CIKs preserved their anti-tumor potency in both in vitro and in vivo conditions. The results initially revealed the great potential of UCB-CIKs for "off-the-shelf" CIK product manufacturing. However, further studies on the effects of cryomedia, freezing rate, and thawing procedure should be undertaken before freshly thawed off-the-shelf UCB-CIKs are utilized in clinical trials.
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Células Matadoras Induzidas por Citocinas , Neoplasias , Animais , Humanos , Camundongos , Proliferação de Células , Células Cultivadas , Sangue Fetal , Neoplasias/patologiaRESUMO
BACKGROUND: The attraction of cappuccino-style beverages is attributed to the foam layer, as it greatly improves the texture, appearance, and taste of these products. Typical milk has a low concentration of free fatty acids (FFAs), but their concentration can increase due to lipolysis during processing and storage, which is detrimental to the foamability and foam stability of milk. There are contradictory results in reported studies concerning the effects of FFAs on the foaming properties of milk due to differences in milk sources, methods inducing lipolysis, and methods of creating foam. In this study, the foaming properties and foam structure of milk samples whose lipolysis was induced by ultra-turraxing, homogenisation, and microfluidisation (1.5-3.5 µ-equiv. mL-1 FFAs) were investigated. RESULTS: Compared with others, microfluidised milk samples had the smallest particle size, lowest absolute zeta potential, and highest surface tension; thus exhibited high foamability and foam stability, and very small and homogeneous air bubbles in foam structure. For all shearing methods, increasing FFA content from 1.5 to 3.5 µ-equiv. mL-1 markedly decreased the surface tension, foamability, and foam stability of milk samples. The FFA level that led to undesirable foam structure was 1.5 µ-equiv. mL-1 for ultra-turraxed milk samples and 2.5 µ-equiv. mL-1 for homogenised and microfluidised ones. CONCLUSION: Shearing-induced lipolysis greatly affected the physical properties of milk samples and subsequently their foaming properties and foam structure. At the same FFA level, lipolysis induced by microfluidisation was much less detrimental to the foaming properties of milk than lipolysis induced by ultra-turraxing and homogenisation. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Lipólise , Leite , Animais , Leite/química , Ácidos Graxos não Esterificados/análise , Tamanho da PartículaRESUMO
Background Consistency in reporting Breast Imaging Reporting and Data System (BI-RADS) breast density on mammograms is important because breast density is used for breast cancer risk assessment and is reported directly to women and clinicians to inform decisions about supplemental screening. Purpose To assess the consistency of BI-RADS density reporting between digital breast tomosynthesis (DBT) and digital mammography (DM) and evaluate density as a breast cancer risk factor when assessed using DM versus DBT. Materials and Methods The Breast Cancer Surveillance Consortium is a prospective cohort study of women undergoing mammography with DM or DBT. This secondary analysis included women aged 40-79 years who underwent at least two screening mammography examinations less than 36 months apart. Percentage agreement and κ statistic were estimated for pairs of BI-RADS density assessments. Cox proportional hazards regression was used to calculate hazard ratios (HRs) of breast density as a risk factor for invasive breast cancer. Results A total of 403 326 pairs of mammograms from 342 149 women were evaluated. There were no significant differences in breast density assessment in pairs consisting of one DM and one DBT examination (57 516 of 74 729 [77%]; κ = 0.64), two DM examinations (238 678 of 301 743 [79%]; κ = 0.67), and two DBT examinations (20 763 of 26 854 [77%]; κ = 0.65). Results were similar when restricting the analyses to pairs read by the same radiologist. The breast cancer HRs for breast density were similar for DM and DBT (P = .45 for interaction). The HRs for density acquired using DM and DBT, respectively, were 0.55 (95% CI: 0.49, 0.63) and 0.37 (95% CI: 0.21, 0.66) for almost entirely fat, 1.47 (95% CI: 1.37, 1.58) and 1.36 (95% CI: 1.02, 1.82) for heterogeneously dense, and 1.72 (95% CI: 1.54, 1.93) and 2.05 (95% CI: 1.25, 3.36) for extremely dense breasts. Conclusion Radiologist reporting of Breast Imaging Reporting and Data System density obtained with digital breast tomosynthesis did not differ from that obtained with digital mammography. © RSNA, 2021 Online supplemental material is available for this article.
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Densidade da Mama , Mamografia/métodos , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Sistema de Registros , Reprodutibilidade dos Testes , Medição de Risco , Programa de SEER , Estados UnidosRESUMO
Nanoemulsion-based systems are widely applied in food industries for protecting active ingredients against oxidation and degradation and controlling the release rate of active core ingredients under particular conditions. Visualizing the interface morphology and measuring the interfacial interaction forces of nanoemulsion droplets are essential to tailor and design intelligent nanoemulsion-based systems. Atomic force microscopy (AFM) is being established as an important technique for interface characterization, due to its unique advantages over traditional imaging and surface force-determining approaches. However, there is a gap in knowledge about the applicability of AFM in characterizing the droplet interface properties of nanoemulsions. This review aims to describe the fundamentals of the AFM technique and nanoemulsions, mainly focusing on the recent use of AFM to investigate nanoemulsion properties. In addition, by reviewing interfacial studies on emulsions in general, perspectives for the further development of AFM to study nanoemulsions are also discussed.
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Microscopia de Força Atômica , Emulsões , Microscopia de Força Atômica/métodosRESUMO
For many dairy products such as cappuccino-style beverages, the top foam layer determines the overall product quality (e.g. their appearance, texture, mouthfeel and coffee aroma release rate) and the consumer acceptance. Proteins in milk are excellent foaming agents, but the foaming properties of milk are greatly affected by several factors such as the protein content, ratio of caseins to whey proteins, casein micelle size, pH, minerals, proteolysis, presence of low molecular weight compounds (lipids and their hydrolyzed products) and high molecular weight compounds (polysaccharides); milk processing conditions (e.g. homogenization, heat treatment and aging); and foaming method and temperature. These factors either induce changes in the molecular structure, charge and surface activity of the milk proteins; or interfere and/or compete with milk proteins in the formation of highly viscoelastic film to stabilize the foam. Some factors affect the foamability while others determine the foam stability. In this review, functionality of milk proteins in the production and stabilization of liquid foam, under effects of these factors is comprehensively discussed. This will help to control the foaming process of milk on demand for a particular application, which still is difficult and challenging for researchers and the dairy industry.
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Proteínas do Leite , Leite , Animais , Caseínas/análise , Caseínas/química , Micelas , Leite/química , Proteínas do Leite/química , Proteínas do Soro do Leite/químicaRESUMO
OBJECTIVES: The aim of the study was to compare the intestinal microbiome in very low birth weight (VLBW) infants who received different enteral iron supplementation (EIS) doses. STUDY DESIGN: Longitudinal stool collection in 80 VLBW infants were conducted up to 2âmonths postnatally in a prospective study. The 16S rRNA regions V4 was used to calculate microbiome compositions and the Piphillin software was used for bacterial functional prediction. Linear mixed effect models and Wilcoxon rank-sum tests were performed to examine the relationships between initial EIS dosage and stool microbiome and bacterial functional potential. RESULTS: There were 105 samples collected before and 237 collected after EIS started from infants with birth gestational age and weight of 28.1â±â2.4âweeks and 1103â±â210âg, respectively. The average postnatal age at start of EIS was 17.9â±â6.9âdays and the average initial EIS dose was 4.8â±â1.1âmgâ·âkg-1â·âday-1. Infants who were started on ≥6âmgâ·âkg-1â·âday-1 had higher abundances of Proteus and Bifidobacterium and a lower alpha diversity than those started on lower doses (Pâ<â0.05). Infants given higher EIS doses had higher bacterial predicted functional potentials for ferroptosis and epithelial invasion after 2âweeks post EIS. CONCLUSIONS: Higher EIS dosage is linked to higher abundances of Proteus and Bifidobacterium, and a less diverse microbiome and higher predicted potential of bacterial epithelial invasion. These observational findings should be further studied in a randomized study to elucidate the optimal dosage of EIS in VLBW infants.
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Microbioma Gastrointestinal , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Recém-Nascido de muito Baixo Peso , Ferro , Estudos Prospectivos , RNA Ribossômico 16S/genéticaRESUMO
OBJECTIVE: To examine the association between developmental timing of initial exposure to racial discrimination and cardiovascular health conditions. DESIGN: Using data from the 1995 Detroit Area Study, logistic and negative binomial regression models were used to assess the association between timing of initial exposure to racial/ethnic discrimination, classified as early childhood (0-7), childhood (8-12), adolescence (13-19), and adulthood (>19), on physician-diagnosed cardiovascular health conditions during adulthood. Each analysis adjusted for age, gender, race/ethnicity, income, education, marital status, health-related behaviors, and pre-existing health conditions. RESULTS: Of the 1,106 participants in the final sample, 520 identified as White and 586 identified as Black. Over half (64%) of the sample experienced at least one major cardiovascular health event at the time of the study, with 39% reporting two or more events. Results from logistic regression models showed that initial exposure to racial discrimination during early childhood was associated with a 2.96 (95%CI:1.15, 7.83) times greater odds of having any cardiovascular-related health condition later in life compared to individuals who reported no discrimination. Results from negative binomial regression models demonstrated that individuals who reported initial exposure to racial discrimination during early childhood and adolescence had a CVD incidence rate that was 1.63 (95%CI:1.11, 2.38) and 1.37 (95%CI:1.10, 1.69) times higher than individuals who reported no discrimination. CONCLUSION: Initial exposure to racial discrimination in early childhood and adolescence may increase the risk of cardiovascular conditions later in life. Clinicians and researchers should consider racial discrimination during childhood as a possible risk factor for illness and disease.
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Doenças Cardiovasculares , Racismo , Adolescente , Adulto , Doenças Cardiovasculares/epidemiologia , Pré-Escolar , Etnicidade , Humanos , Renda , Fatores de RiscoRESUMO
OBJECTIVE: Feeding intolerance (FI) is a common presentation of necrotizing enterocolitis (NEC) and sepsis. NEC and sepsis are associated with hematological changes, but these changes alone are not reliable biomarkers for early diagnosis. This study examined whether the combination of hematological indices and FI can be used as an early diagnostic tool for NEC or sepsis. STUDY DESIGN: This retrospective cohort study included infants born at <1,500 g or <30 weeks who had symptoms of FI. The exclusion criteria were congenital or chromosomal disorders, thrombocytopenia or platelet transfusion before the onset of FI, and history of bowel resection. We compared the hematological indices from infants with pathologic FI (due to NEC or sepsis) to infants with benign FI. RESULTS: During the study period, 211 infants developed FI; 185 met the inclusion criteria. Infants with pathologic FI (n = 90, 37 cases with NEC and 53 with sepsis) had lower birth gestational age and weight compared with 95 infants with benign FI (n = 95). Pathologic FI was associated with lower platelet count (median 152 × 103/µL vs. 285 × 103/µL, p < 0.001) and higher immature-to-total neutrophil (I/T) ratio (median 0.23 vs. 0.04, p < 0.001) at the onset of FI. Pathologic FI was also associated with a decrease in baseline platelets compared with an increase in benign FI. For diagnosis of pathologic FI, a decrease ≥10% in platelets from baseline had a sensitivity and specificity of 0.64 and 0.73, respectively, I/T ratio ≥0.1 had a sensitivity and specificity of 0.71 and 0.78, respectively, and the combination of both parameters had a sensitivity and specificity of 0.50 and 0.97, respectively. CONCLUSION: FI caused by NEC or sepsis was associated with a decrease in platelets from baseline, and a lower platelet level and higher I/T ratio at the onset of FI. These findings can help clinicians in the management of preterm infants with FI. KEY POINTS: · FI is a common presentation of NEC and sepsis in preterm infants.. · FI due to NEC or sepsis is associated with changes in platelets and I/T ratio.. · These changes could be useful as early markers for diagnosis..
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Enterocolite Necrosante/diagnóstico , Intolerância Alimentar/etiologia , Neutrófilos/imunologia , Sepse/diagnóstico , Biomarcadores/sangue , Plaquetas , Diagnóstico Precoce , Enterocolite Necrosante/sangue , Enterocolite Necrosante/imunologia , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Contagem de Leucócitos , Modelos Logísticos , Masculino , Neutrófilos/metabolismo , Estudos Retrospectivos , Sensibilidade e Especificidade , Sepse/sangue , Sepse/imunologiaRESUMO
Exposure to discrimination or unfair treatment has emerged as an important risk factor for illness and disease that disproportionately affects racial and ethnic minorities. Discriminatory experiences may operate like other stressors in that they activate physiological responses that adversely affect the maintenance of homeostasis. Research suggests that inflammation plays a critical role in the pathophysiology of stress-related diseases. Recent findings on discrimination and inflammation are discussed. We highlight limitations in the current evidence and provide recommendations for future studies that seek to examine the association between discrimination and inflammation.
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Etnicidade , Grupos Raciais , Humanos , Inflamação , Grupos Minoritários , Fatores de RiscoRESUMO
BACKGROUND: Premature infants often develop enteric dysbiosis with a preponderance of Gammaproteobacteria, which has been related to adverse clinical outcomes. We investigated the relationship between increasing fecal Gammaproteobacteria and mucosal inflammation, measured by fecal calprotectin (FC). METHODS: Stool samples were collected from very-low-birth weight (VLBW) infants at ≤2, 3, and 4 weeks' postnatal age. Fecal microbiome was surveyed using polymerase chain reaction amplification of the V4 region of 16S ribosomal RNA, and FC was measured by enzyme immunoassay. RESULTS: We enrolled 45 VLBW infants (gestation 27.9 ± 2.2 weeks, birth weight 1126 ± 208 g) and obtained stool samples at 9.9 ± 3, 20.7 ± 4.1, and 29.4 ± 4.9 days. FC was positively correlated with the genus Klebsiella (r = 0.207, p = 0.034) and its dominant amplicon sequence variant (r = 0.290, p = 0.003), but not with the relative abundance of total Gammaproteobacteria. Klebsiella colonized the gut in two distinct patterns: some infants started with low Klebsiella abundance and gained these bacteria over time, whereas others began with very high Klebsiella abundance. CONCLUSION: In premature infants, FC correlated with relative abundance of a specific pathobiont, Klebsiella, and not with that of the class Gammaproteobacteria. These findings indicate a need to define dysbiosis at genera or higher levels of resolution.
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Disbiose/diagnóstico , Complexo Antígeno L1 Leucocitário/análise , Peso ao Nascer , Disbiose/microbiologia , Enterocolite Necrosante/microbiologia , Fezes/química , Feminino , Gammaproteobacteria/isolamento & purificação , Microbioma Gastrointestinal , Idade Gestacional , Humanos , Lactente , Lactente Extremamente Prematuro , Recém-Nascido , Recém-Nascido Prematuro , Doenças do Prematuro , Recém-Nascido de muito Baixo Peso , Inflamação , Unidades de Terapia Intensiva Neonatal , Infecções por Klebsiella/diagnóstico , Masculino , Estudos Prospectivos , RNA Ribossômico 16S , Curva ROC , Sensibilidade e EspecificidadeRESUMO
Water-induced crystallisation of amorphous core-cyclodextrin (CD) complex is an essential step in a solid encapsulation process and removal of added water is a challenging. Ethanol addition is expected to shorten the complex dehydration time. This study investigated crystallisation of amorphous spray-dried α-, ß- and γ-CD powders by direct mixing 15% (w/w) of ethanol:water mixture (0:100, 20:80, 40:60, 60:40, 80:20 and 100:0) over 72 h period. The results showed α- and ß-CD powders crystallised at all concentrations of ethanol solutions. Especially mixed with 0:100 and 20:80 ethanol:water solutions, the crystallisation behaviour of α- and ß-CD powders was similar to that of commercial crystalline counterparts. γ-CD powders exhibited a crystallisation sign as mixed with 0:100 and 20:80 ethanol:water solutions only. In the study of fish oil encapsulation using the mixture of water and ethanol to induce the complex crystallisation, only γ-CD powder was able to form complex with fish oil.
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Recent innovative approaches to stabilize and crystallize GPCRs have resulted in an unprecedented breakthrough in GPCR crystal structures as well as application of the purified receptor protein in biophysical and biochemical ligand binding assays. However, the protein optimization process to enable these technologies is lengthy and requires iterative overexpression, solubilization, purification and functional analysis of tens to hundreds of protein variants. Here, we report a new and versatile method to screen in parallel hundreds of GPCR variants in HEK293 produced virus-like particles (VLPs) for protein yield, stability, functionality and ligand binding. This approach reduces the time and resources during GPCR construct optimization by eliminating lengthy protein solubilization and purification steps and by its adaptability to many binding assay formats (label or label-free detection). We exemplified the robustness of our VLP method by screening 210 GALR3-VLP variants in a radiometric agonist-based binding assay and a subset of 88 variants in a label-free antagonist-based assay. The resulting GALR3 agonist or antagonist stabilizing variants were then further used for recombinant protein expression in transfected insect cells. The final purified protein variants were successfully immobilized on a biosensor chip and used in a surface plasmon resonance binding assay.
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Expressão Gênica , Receptor Tipo 3 de Galanina , Proteínas Recombinantes de Fusão , Vírion , Células HEK293 , Humanos , Estabilidade Proteica , Receptor Tipo 3 de Galanina/biossíntese , Receptor Tipo 3 de Galanina/química , Receptor Tipo 3 de Galanina/genética , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Vírion/química , Vírion/genética , Vírion/metabolismoRESUMO
Food powders can exist in amorphous, crystalline or mixed structure depending on the order of molecular arrangement in the powder particle matrices. In food production, the structure of powders has a greatly effect on their stability, functionality, and applicability. The undesirable structure of powders can be accidentally formed during production. Therefore, characterization of powder structure as well as quantification of amorphous-crystalline proportions presenting in the powders are essential to control the quality of products during storage and further processing. For these purposes, many analytical techniques with large differences in the degree of selectivity and sensitivity have been developed. In this review, differences in the structure of food powders are described with a focus being placed on applications of amorphous powders. Essentially, applicability of common analytical techniques including X-ray, microscopic, vapor adsorption, thermal, and spectroscopic approaches for quantitative and qualitative structural characterization of food powders is also discussed.
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Alimentos , Pós/química , Água/química , Adsorção , Cristalização , Cristalografia por Raios X , Tamanho da PartículaRESUMO
Stability and release properties of CO2-α-cyclodextrin complex powder prepared by solid encapsulation (water activity, aw ≈ 0.95) followed by moisture removal using silica gel and CaCl2 desiccants during post-dehydration were investigated. The results showed that CaCl2 reduced aw much faster than silica gel did under the same conditions. After approximately 60 h, aw of complex powders reduced using silica gel was almost constant at 0.247 (±0.012), while those treated with CaCl2, aw was 0.225 (±0.005) and had not yet reached their lowest value. Moisture adsorption by silica gel and CaCl2 also led to a decrease in the CO2 concentration of complex powder (higher decrease for silica gel adsorption) without affecting the structure and morphology of complex powder. The CO2 release properties of CaCl2-aw-reduced complex powder at different relative humidities (32.73, 52.86, 75.32 and 97.30% RH), liquid environments (water and oil) and packaging methods (normal and vacuum) were also studied.
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Dióxido de Carbono/administração & dosagem , Dessecação/métodos , Higroscópicos/química , alfa-Ciclodextrinas/química , Adsorção , Cloreto de Cálcio/química , Dióxido de Carbono/química , Umidade , Pós , Sílica Gel/químicaRESUMO
Glucuronoxylans (GX), particularly crude fractions obtained by pressurized hot water extraction of birch wood, act as potent emulsifiers and stabilizers against physical separation and lipid oxidation. Herein, we studied the adsorption of GX on hydrophobic interfaces to correlate their multicomponent character towards the formation of interfacial layers in emulsions. Dynamic interfacial tension (DIFT) and quartz crystal microgravimetry with dissipation monitoring (QCM-D) were applied to various GX fractions and the results compared with those from cellulose-based emulsifiers. The roles of residual lignin and polysaccharides are discussed considering the formation of interfacial layers during emulsification. The DIFT of the different GXs reached quasi-equilibrium faster as the lignin concentration increased, implying a correlation between the rate of adsorption and the residual lignin content. The effect of NaCl addition was more pronounced in polysaccharide-rich fractions, indicating that the polysaccharide fraction modulated the effect of ionic strength. QCM-D showed that despite the fast adsorption exhibited by the lignin-rich GX extract in the DIFT curves, the adsorbed materials were lightweight, suggesting that the polysaccharide fraction built the bulk of the interfacial layer. These results provide a foundation towards understanding the role of GX in interfacial stabilization beyond traditional plant-based counterparts.
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The immune system maintains constant surveillance to prevent the infiltration of both endogenous and exogenous threats into host organisms. The process is regulated by effector immune cells that combat external pathogens and regulatory immune cells that inhibit excessive internal body inflammation, ultimately establishing a state of homeostasis within the body. Disruption to this process could lead to autoimmunity, which is often associated with the malfunction of both T cells and B cells with T cells playing a more major role. A number of therapeutic mediators for autoimmune diseases are available, from conventional disease-modifying drugs to biologic agents and small molecule inhibitors. Recently, ribosomally synthesized peptides, specifically cyclotides from plants are currently attracting more attention as potential autoimmune disease therapeutics due to their decreased toxicity compared to small molecules inhibitors as well as their remarkable stability against a number of factors. This review provides a concise overview of various cyclotides exhibiting immunomodulatory properties and their potential as therapeutic interventions for autoimmune diseases.