15 research outputs found
Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19
IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19.
Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19.
DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 nonâcritically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022).
INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (nâ=â257), ARB (nâ=â248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; nâ=â10), or no RAS inhibitor (control; nâ=â264) for up to 10 days.
MAIN OUTCOMES AND MEASURES The primary outcome was organ supportâfree days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes.
RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ supportâfree days among critically ill patients was 10 (â1 to 16) in the ACE inhibitor group (nâ=â231), 8 (â1 to 17) in the ARB group (nâ=â217), and 12 (0 to 17) in the control group (nâ=â231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ supportâfree days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively).
CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes.
TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570
Lactic Acid Bacteria Simultaneously Encapsulate Diverse Bioactive Compounds from a Fruit Extract and Enhance Thermal Stability
This study develops an innovative cell-based carrier to simultaneously encapsulate multiple phytochemicals from a complex plant source. Muscadine grapes (MG) juice prepared from fresh fruit was used as a model juice. After incubation with inactivated bacterial cells, 66.97% of the total anthocyanins, and 72.67% of the total antioxidant compounds were encapsulated in the cells from MG juice. Confocal images illustrated a uniform localization of the encapsulated material in the cells. The spectral emission scans indicated the presence of a diverse class of phenolic compounds, which was characterized using high-performance liquid chromatography (HPLC). Using HPLC, diverse phytochemical compound classes were analyzed, including flavanols, phenolic acid, hydroxycinnamic acid, flavonols, and polymeric polyphenols. The analysis validated that the cell carrier could encapsulate a complex profile of bioactive compounds from fruit juice, and the encapsulated content and efficiencies varied by the chemical class and compound. In addition, after the heat treatment at 90 °C for 60 min, >87% total antioxidant capacity and 90% anthocyanin content were recovered from the encapsulated MG. In summary, these results highlight the significant potential of a selected bacterial strain for simultaneous encapsulation of diverse phenolic compounds from fruit juice and improving their process stability
Solvatochromic Probe Response within Ionic Liquids and Their Equimolar Mixtures with Tetraethylene Glycol
Synergism
in a probe response within a mixture hints at the presence
of strong interactions involving the solvent constituents of the mixture
and possibly the probe. Unusual and rare âhyperpolarityâ
resulting from the synergism in probe response exhibited by ionic
liquid (IL) mixtures with glycol family solvents is investigated in
detail for equimolar mixtures of tetraethylene glycol (TEG) with many
structurally different ILs using several UVâvis absorbance
and fluorescence solvatochromic probes. Thirteen different ILs, of
the same cation 1-butyl-3-methylimidazolium and different anions,
of the same anion bisÂ(trifluoromethylsulfonyl)Âimide and different
cations, and of C2 methyl-substituted imidazolium cations, are used
to assess the structural dependence of the IL on synergism exhibited
by (IL + TEG) mixture. Responses from UVâvis absorbance probes
are used to obtain <i>E</i><sub>T</sub> [dipolarity/polarizability
and/or H-bond donating (HBD) acidity] and KamletâTaft parameters
[Ï* (dipolarity/polarizability), α (HBD acidity), and
ÎČ (HB accepting basicity)] within (IL + TEG) mixtures. The band
I-to-band III fluorescence intensity ratio of dipolarity probe pyrene
along with the lowest energy fluorescence band maxima of pyrene-1-carboxaldehyde
(PyCHO, a probe for the permittivity of the medium), coumarin-153
and <i>N</i>,<i>N</i>-dimethyl-6-propionyl-2-naphthylamine
PRODAN (neutral photoinduced charge-transfer fluorescence probes),
and 6-<i>p</i>-toluidine-2-naphthalenesulfonic acid (TNS)
and l-anilinonaphthalene-8-sulfonate (ANS) (ionic photoinduced charge-transfer
fluorescence probes) are used to assess whether synergism is exhibited
by (IL + TEG) equimolar mixtures. Probe responses within TEG equimolar
mixtures with ILs are compared to those with common organic solvents.
An attempt is made to establish a correlation between the synergism
observed in the probe response within an (IL + TEG) mixture and the
structural features of the cation and anion of the IL, such as acidity
of the protons of the cation, aromaticity of the cation, and size,
shape, and coordinating ability of the anion. It is established that
the solvatochromism exhibited by the probes within (IL + TEG) mixtures
is due to complex coupling of several different interactions and dynamical
processes involving the probe as well as IL and TEG within the mixture
Evidence of Water-in-Ionic Liquid Microemulsion Formation by Nonionic Surfactant Brij-35
Brij-35,
a common and popular nonionic surfactant, is shown to
form water-in-ionic liquid (w/IL) microemulsions with IL 1-butyl-3-methylimidazolium
hexafluorophosphate ([bmim]Â[PF<sub>6</sub>]) as the bulk phase. The
presence of w/[bmim]Â[PF<sub>6</sub>] microemulsions is hinted by the
significantly increased solubility of water in Brij-35 solution of
[bmim]Â[PF<sub>6</sub>]. The formation of w/[bmim]Â[PF<sub>6</sub>]
microemulsions by Brij-35 is confirmed using dynamic light scattering
(DLS) and small-angle X-ray scattering (SAXS) measurements. Brij-35
forms reverse micelle-type aggregates within [bmim]Â[PF<sub>6</sub>] in the absence of added-water. These reverse micelles become w/[bmim]Â[PF<sub>6</sub>] microemulsions as the water is added to the system. As the
water loading (<i>w</i><sub>0</sub>) is increased, the average
diameter of the aggregates increases. Fourier transform infrared (FTIR)
absorbance data reveal the presence of both âboundâ
and âfreeâ water within the system. The âboundâ
water is associated with the water pools of the w/[bmim]Â[PF<sub>6</sub>] microemulsions. Excited-state proton transfer (ESPT) involving
probe pyranine shows deprotonation of pyranine within the water pools
of the w/[bmim]Â[PF<sub>6</sub>] microemulsions
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Synergistic Antimicrobial Activity by Light or Thermal Treatment and Lauric Arginate: Membrane Damage and Oxidative Stress.
The need for more effective antimicrobials is critical for the food industry to improve food safety and reduce spoilage of minimally processed foods. The present study was initiated to develop an efficient and novel antimicrobial approach which combines physical treatments (UV-A or mild heat) and generally recognized as safe lauroyl arginate ethyl (LAE) to inactivate surrogate strains, including Escherichia coli and Listeria innocua Synergistic inactivation of bacteria resulted in an âŒ6-log reduction of target bacteria, while individual treatments resulted in <1.5-log inactivation under the same set of conditions. In addition, the synergistic mechanism between LAE and UV-A/mild heat was evaluated by supplementing with a variety of antioxidants for suppressing oxidative stress and measurement of cell membrane damage by nucleic acid release. These results demonstrate that the synergistic antimicrobial activity of LAE and mild physical stresses was suppressed by supplementation with antioxidants. The research also compared LAE with another membrane-targeting lipopeptide antimicrobial agent, polymyxin B, to understand the uniqueness of LAE-induced synergy. Briefly, differences in modes of action between LAE and polymyxin B were characterized by comparing the MIC, damage to liposomes, and oxidative stress generation. These differences in the mode of action between LAE and polymyxin B suggested that both compounds target cell membrane but significantly differ in mechanisms, including membrane disruption and oxidative stress generation. Overall, this study illustrates synergistic antimicrobial activity of LAE with light or mild heat and indicates a novel oxidative stress pathway that enhances the activity of LAE beyond membrane damage.IMPORTANCE This study highlights an effective antimicrobial processing approach using a novel combination of lauroyl arginate ethyl (LAE) and two different physical treatments, light (UV-A) and mild heat. Both combinations demonstrated synergistic inactivation against a model Gram-negative bacterium or a Gram-positive bacterium or both by a >5-log reduction. Further mechanistic study revealed that oxidative stress is responsible for synergistic inactivation between LAE and UV-A, while both membrane damage and oxidative stress are responsible for the synergistic combination between LAE and mild heat. The mode of action of LAE was further compared to that of polymyxin B and analyzed using artificial membrane model systems and the addition of antioxidants. The proposed combination of LAE and common physical treatments may improve food preservation, food safety, and current sanitation processes for the food industry and the inactivation of pathogenic strains in biomedical environments
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Synergistic inactivation of bacteria based on a combination of low frequency, low-intensity ultrasound and a food grade antioxidant.
This study evaluated a synergistic antimicrobial treatment using a combination of low frequency and a low-intensity ultrasound (LFU) and a food-grade antioxidant, propyl gallate (PG), against a model gram-positive (Listeria innocua) and the gram-negative bacteria (Escherichia coli O157:H7). Bacterial inactivation kinetic measurements were complemented by characterization of biophysical changes in liposomes, changes in bacterial membrane permeability, morphological changes in bacterial cells, and intracellular oxidative stress upon treatment with PG, LFU, and a combination of PG + LFU. Combination of PG + LFU significantly (>4 log CFU/mL, P < 0.05) enhanced the inactivation of both L. innocua and E. coli O157:H7 compared to PG or LFU treatment. As expected, L. innocua had a significantly higher resistance to inactivation compared to E. coli using a combination of PG + LFU. Biophysical measurements in liposomes, bacterial permeability measurements, and scanning electron microscope (SEM)-based morphological measurements show rapid interactions of PG with membranes. Upon extended treatment of cells with PG + LFU, a significant increase in membrane damage was observed compared to PG or LFU alone. A lack of change in the intracellular thiol content following the combined treatment and limited effectiveness of exogenously added antioxidants in attenuating the synergistic antimicrobial action demonstrated that oxidative stress was not a leading mechanism responsible for the synergistic inactivation by PG + LFU. Overall, the study illustrates synergistic inactivation of bacteria using a combination of PG + LFU based on enhanced membrane damage and its potential for applications in the food and environmental systems
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Investigating Milk Fat Globule Structure, Size, and Functionality after Thermal Processing and Homogenization of Human Milk.
Human milk provides bioactive compounds such as milk fat globules (MFGs), which promote brain development, modulate the immune system, and hold antimicrobial properties. To ensure microbiological safety, donor milk banks apply heat treatments. This study compares the effects of heat treatments and homogenization on MFGs physicochemical properties, bioactivity, and bioavailability. Vat pasteurization (Vat-PT), retort (RTR), and ultra-high temperature (UHT) were performed with or without homogenization. UHT, RTR, and homogenization increased the colloidal dispersion of globules, as indicated by increased zeta potential. The RTR treatment completely inactivated xanthine oxidase activity (a marker of MFG bioactivity), whereas UHT reduced its activity by 93%. Interestingly, Vat-PT resulted in less damage, with 28% activity retention. Sialic acid, an important compound for brain health, was unaffected by processing. Importantly, homogenization increased the in vitro lipolysis of MFG, suggesting that this treatment could increase the digestibility of MFG. In terms of color, homogenization led to higher L* values, indicating increased whiteness due to finer dispersion of the fat and casein micelles (and thus greater light scattering), whereas UHT and RTR increased b* values associated with Maillard reactions. This study highlights the nuanced effects of processing conditions on MFG properties, emphasizing the retention of native characteristics in Vat-PT-treated human milk
Self-Aggregation of Sodium Dodecyl Sulfate within (Choline Chloride + Urea) Deep Eutectic Solvent
Deep eutectic solvents (DESs) have
shown tremendous promise as
green solvents with low toxicity and cost. Understanding molecular
aggregation processes within DESs will not only enhance the application
potential of these solvents but also help alleviate some of the limitations
associated with them. Among DESs, those comprising choline chloride
and appropriate hydrogen-bond donors are inexpensive and easy to prepare.
On the basis of fluorescence probe, electrical conductivity, and surface
tension experiments, we present the first clear lines of evidence
for self-aggregation of an anionic surfactant within a DES containing
a small fraction of water. Namely, well-defined assemblies of sodium
dodecyl sulfate (SDS) apparently form in the archetype DES Reline
comprising a 1:2 molar mixture of choline chloride and urea. Significant
enhancement in the solubility of organic solvents that are otherwise
not miscible in choline chloride-based DESs is achieved within Reline
in the presence of SDS. The remarkably improved solubility of cyclohexane
within SDS-added Reline is attributed to the presence of spontaneously
formed cyclohexane-in-Reline microemulsions by SDS under ambient conditions.
Surface tension, dynamic light scattering (DLS), small-angle X-ray
scattering (SAXS), density, and dynamic viscosity measurements along
with responses from the fluorescence dipolarity and microfluidity
probes of pyrene and 1,3-bisÂ(1-pyrenyl)Âpropane are employed to characterize
these aggregates. Such water-free oil-in-DES microemulsions are appropriately
sized to be considered as a new type of nanoreactor
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Yeast cell vacuum infusion into fungal pellets as a novel cell encapsulation methodology.
Immobilized yeast cells are used industrially in winemaking processes such as sparkling wine and Sherry wine production. Here, a novel approach has been explored for the infusion and immobilization of yeast cells into filamentous fungal pellets, which serve as a porous natural material. This was accomplished through vacuum application to force the yeast cells towards the core of the fungal pellets followed by culture in YPD medium to promote their growth from the interior. This method represents an improved variation of a previous approach for the assembly of yeast biocapsules, which entailed the co-culture of both fungal and yeast cells in the same medium. A comparison was made between both techniques in terms of biocapsule productivity, cell retention capacity, and cell biological activity through an alcoholic fermentation of a grape must. The results indicated a substantial increase in biocapsule productivity (37.40-fold), higher cell retention within the biocapsules (threefold), and reduction in cell leakage during fermentation (twofold). Although the majority of the chemical and sensory variables measured in the produced wine did not exhibit notable differences from those produced utilizing suspended yeast cells (conventional method), some differences (such as herbaceous and toasted smells, acidity, bitterness, and persistence) were perceived and wines positively evaluated by the sensory panel. As the immobilized cells remain functional and the encapsulation technique can be expanded to other microorganisms, it creates potential for additional industrial uses like biofuel, health applications, microbe encapsulation and delivery, bioremediation, and pharmacy. KEY POINTS: âą New approach improves biocapsule productivity and cell retention. âą Immobilized yeast remains functional in fermentation. âą Wine made with immobilized yeast had positive sensory differences