Accounting for effective interactions among charged microgels

We introduce a theoretical approach to describe structural correlations among charged permeable spheres at finite particle concentrations. This theory explicitly accounts for correlations among microions and between microions and macroions and allows for the proposal of an effective interaction among macroions that successfully captures structural correlations observed in poly- N -isopropyl acrylamide microgel systems. In our description the bare charge is fixed and independent of the microgel size, the microgel concentration, and the ionic strength, which contrasts with results obtained using linear response approximations, where the bare charge needs to be adapted to properly account for microgel correlations obtained at different conditions

Time to Switch to Second-line Antiretroviral Therapy in Children With Human Immunodeficiency Virus in Europe and Thailand.

Background: Data on durability of first-line antiretroviral therapy (ART) in children with human immunodeficiency virus (HIV) are limited. We assessed time to switch to second-line therapy in 16 European countries and Thailand. Methods: Children aged <18 years initiating combination ART (≥2 nucleoside reverse transcriptase inhibitors [NRTIs] plus nonnucleoside reverse transcriptase inhibitor [NNRTI] or boosted protease inhibitor [PI]) were included. Switch to second-line was defined as (i) change across drug class (PI to NNRTI or vice versa) or within PI class plus change of ≥1 NRTI; (ii) change from single to dual PI; or (iii) addition of a new drug class. Cumulative incidence of switch was calculated with death and loss to follow-up as competing risks. Results: Of 3668 children included, median age at ART initiation was 6.1 (interquartile range (IQR), 1.7-10.5) years. Initial regimens were 32% PI based, 34% nevirapine (NVP) based, and 33% efavirenz based. Median duration of follow-up was 5.4 (IQR, 2.9-8.3) years. Cumulative incidence of switch at 5 years was 21% (95% confidence interval, 20%-23%), with significant regional variations. Median time to switch was 30 (IQR, 16-58) months; two-thirds of switches were related to treatment failure. In multivariable analysis, older age, severe immunosuppression and higher viral load (VL) at ART start, and NVP-based initial regimens were associated with increased risk of switch. Conclusions: One in 5 children switched to a second-line regimen by 5 years of ART, with two-thirds failure related. Advanced HIV, older age, and NVP-based regimens were associated with increased risk of switch

Effects of Annual Growth Conditions on Phenolic Compounds and Antioxidant Activity in the Roots of <i>Eryngium montanum</i>

Medicinal plants grown in natural settings are exposed to different adverse environmental conditions that determine their growth and development as well as the composition and concentration of secondary metabolites in their organs. The objective of this study was to evaluate the effects of environmental conditions associated with localities and annual growth cycles on the contents of phenolic compounds and flavonoids, antioxidant activity and potentially bioactive phenolic acids in the roots of Eryngium montanum, a medicinal species from temperate Mexico. The samples for composition analysis were collected using a bifactorial design: Factor A consisted of the localities (Morelos and La Unión de San Martin Huamelulpam, Mexico) and Factor B was represented by the annual growth cycle (2020 and 2021). In each sample, the contents of polyphenols and equivalent flavonoids of quercetin and catechin and antioxidant activity were evaluated using spectrophotometry. Subsequently, chlorogenic, caffeic and rosmarinic acids were identified and quantified using high-performance liquid chromatography with diode-array detection (HPLC-DAD). The annual growth conditions and, to a lesser extent, the locality of origin of the samples significantly influenced the contents of phenolic compounds and antioxidant activity. The environmental conditions that occurred in 2021 favored an increase in the contents of phenolic compounds compared to those in 2020, and the same pattern was observed for chlorogenic acid; however, for caffeic and rosmarinic acids, the opposite pattern was observed. The content of phenolic acids in the roots of E. montanum follows different and independent patterns between cycles based on the interaction between the locality of origin and annual growth cycle. This study quantifies the magnitude of the total environmental effect on the phenolic compound concentrations in E. montanum roots, which was measured via sampling during two annual growth cycles, where the sampling locations factor had little influence. The bioactive compounds identified in E. montanum roots have the potential for use as alternative medicines, as mentioned by different families from Oaxaca, Mexico

Effects of Growth Conditions on Phenolic Composition and Antioxidant Activity in the Medicinal Plant Ageratina petiolaris (Asteraceae)

Secondary metabolites, in addition to playing an essential role in the adaptation of plants to the environment and phytochemical responses in recovery processes to stress conditions, are the base material of the healing effect of medicinal plants. In this study, the effect of growth conditions and localities of origin of Ageratina petiolaris on phenolic compounds content and antioxidant activity was evaluated; the plant is used for medicinal purposes in Oaxaca, Mexico. Samples of stem and young leaves were collected from plants growing naturally (in situ) in two locations in Oaxaca and from propagules collected in situ; plants were grown ex situ to obtain a set of equivalent samples to the first sampling (in situ). In both sets of samples, total polyphenol and flavonoid contents and antioxidant activity were evaluated by spectrometry, and later the phenolic acids and flavonoids were also identified and quantified by high-performance liquid chromatography with diode-array detection (HPLC-DAD). The growth conditions of A. petiolaris significantly influenced its phenolic composition and antioxidant activity, where samples collected in situ had a higher phenolic compounds content than did plants grown ex situ. Five phenolic acids and five flavonoids were identified, eight of which had not been reported in A. petiolaris: caffeic acid, &rho;-coumaric acid, robinin, rutin, luteolin-7-glucoside, apigenin-7-glucoside, rosmarinic acid and kaempferol, in terms of HPLC-DAD analysis

Effects of Growth Conditions on Phenolic Composition and Antioxidant Activity in the Medicinal Plant <i>Ageratina petiolaris</i> (Asteraceae)

Secondary metabolites, in addition to playing an essential role in the adaptation of plants to the environment and phytochemical responses in recovery processes to stress conditions, are the base material of the healing effect of medicinal plants. In this study, the effect of growth conditions and localities of origin of Ageratina petiolaris on phenolic compounds content and antioxidant activity was evaluated; the plant is used for medicinal purposes in Oaxaca, Mexico. Samples of stem and young leaves were collected from plants growing naturally (in situ) in two locations in Oaxaca and from propagules collected in situ; plants were grown ex situ to obtain a set of equivalent samples to the first sampling (in situ). In both sets of samples, total polyphenol and flavonoid contents and antioxidant activity were evaluated by spectrometry, and later the phenolic acids and flavonoids were also identified and quantified by high-performance liquid chromatography with diode-array detection (HPLC-DAD). The growth conditions of A. petiolaris significantly influenced its phenolic composition and antioxidant activity, where samples collected in situ had a higher phenolic compounds content than did plants grown ex situ. Five phenolic acids and five flavonoids were identified, eight of which had not been reported in A. petiolaris: caffeic acid, ρ-coumaric acid, robinin, rutin, luteolin-7-glucoside, apigenin-7-glucoside, rosmarinic acid and kaempferol, in terms of HPLC-DAD analysis

Phenolic Compounds and Antioxidant Activity in Edible Flower Species from Oaxaca

In Mexico, the tradition of consuming flowers dates to pre-Columbian times, and flower consumption persists today; however, this practice is typically unknown outside the regions where flowers are used in local gastronomy. The aim of this work was to evaluate the variation in polyphenol and flavonoid contents and antioxidant activity in inflorescence samples. Samples of izote (Yucca filifera), maguey pulquero (Agave salmiana), cuachepil or guachepil (Diphysa americana), and tepejilote or pacaya (Chamaedorea tepejilote) were collected from different communities and regions of Oaxaca, Mexico, during 2022. Specifically, ten to eleven inflorescence samples were collected per species, and their polyphenol and flavonoid contents and antioxidant activity were evaluated using UV–visible spectrophotometry and reference standards. Significant differences were detected between and within samples depending on their geographical origin (collection locations); the environment and site influenced the composition of the samples for each species. Across all species, significant and positive correlations of the polyphenol and flavonoid contents were identified with the antioxidant activity detected via the DPPH and FRAP methods. The high variability in phenolic compound contents and antioxidant activity within each species shows that the nutritional and nutraceutical potential of flowers may complement diets at the family and communitarian levels

Plant and Growth Condition Interactions on the Phenolic Compound Contents and Antioxidant Activity in <i>Salvia circinata</i> Cav., a Medicinal Sage

The genus Salvia has a worldwide distribution, and its contribution to traditional medicine and as an aromatic plant has been recognized since ancient times, with few documented species having a similar phytochemical composition. In this study, the effects of natural growth conditions (in situ) and ex situ cultivation and sampling locations on the phenolic compound contents and antioxidant activity of methanolic extracts of Salvia circinata from Oaxaca, Mexico, were investigated. Stem and young leaf samples were collected from plants growing in situ in two locations in Oaxaca and later from plants propagated clonally or vegetatively from propagules obtained in situ but grown ex situ. In both sets of samples, the contents of total polyphenols and flavonoids and the antioxidant activity were evaluated by spectrophotometry, and subsequently, the contents of phenols and specific flavonoids were identified and quantified by high-performance liquid chromatography with diode-array detection (HPLC–DAD). The growth conditions and locality of origin of the samples significantly influenced the contents of total polyphenols and flavonoids and antioxidant activity, with the in situ conditions in the locality of Reforma, Oaxaca, favoring higher levels. Two phenolic acids (chlorogenic and rosmarinic) and two flavonoids (isoquercitrin and rutin) were identified, and the concentrations of these compounds were influenced by the growth conditions and localities of origin of the samples

Evaluation of gut environment in healthy and Alzheimer disease patinets in the context of a Mediterranean diet

Trabajo presentado en la Reunión Conjunta: LXVII Reunión Anual de la Sociedad Argentina de Investigación Clínica (SAIC); LXX Reunión Anual de la Sociedad Argentina de Inmunología (SAI) & 3er Congreso Franco-Argentino de Inmunología (FAIC); Reunión Anual 2022 de la Sociedad argentina de Fisiología (SAFIS), celebrada en Buenos Aires (Argentina), del 16 al 19 de noviembre de 2022Introduction. Mediterranean diet (MD) has been proposed as a dietary pattern model to prevent or delay brain dysfunction by gut manipulation. Alterations of colonic environment including microbial population and derived metabolites have been associated with neurological alterations explained by gut-brain connection. Differences in metabolic profile between healthy and Alzheimer disease (AD) patients may offer the possibility to identify potential target to treat or delay the onset of the disease. The aim of this study was to identify possible metabolic alterations in the colon environment of AD patients compared with matched controls in the context of a MD. Material and methods. Healthy subjects (n=19) and AD patients (n=25) of both sexes, between 55-75 y from La Rioja, Spain, participated in this observational study. Data concerning dietary habits were obtained during personal interview and processed to calculate MD adherence score and nutrients intake. Plasmatic and fecal short chain fatty acids (SCFA) were determined by GC-MS/MS and fecal biomarkers of intestinal inflammation (IL-1β, TNF-α, calprotectin) were quantified by ELISA. Results. Dietary data and intestinal metabolites are reported in control and AD volunteers. Despite similar MD score, the consumption of animal proteins (p=0.048), fruits (p=0.006) and phenol flavones (p=0.013) were different between groups. Feces of controls were enriched in caproic acid (p=0.008) whereas propionic acid (p=0.017) was more abundant in fecal samples of AD patients. In plasma, isovaleric acid was higher in the control group (p=0.041). Regarding the biomarkers of intestinal inflammation, we observed that IL-1β was increased in feces of control volunteers (p=0.008). Correlations among SCFA, IL-1β and dietary parameters were also evaluated. Conclusions. These initial data suggest difference in microbial metabolism among healthy and AD patients which could be considered as possible participants in the gut-brain axis communication