Performance of Focused Assessment with Sonography for Trauma Following Resuscitative Thoracotomy for Traumatic Cardiac Arrest.

BACKGROUND: In patients undergoing resuscitative thoracotomy (RT) for traumatic cardiac arrest, focused assessment with sonography for trauma (FAST) is often used to look for intraperitoneal fluid. These findings can help determine whether abdominal exploration is warranted once return of spontaneous circulation is achieved; however, the diagnostic accuracy of FAST in this clinical scenario has yet to be evaluated. The purpose of this study was to assess the performance of FAST in identifying intra-abdominal hemorrhage following RT. METHODS: We performed a 3-year retrospective study at a high-volume level 1 trauma center from 2014 to 2016. We included patients who underwent RT in the Emergency Department. All FAST examinations were performed by non-radiologists. Operative findings, computed tomography reports, diagnostic peritoneal aspirate (DPA) results, and autopsy findings were used as reference standards to calculate the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the FAST. RESULTS: A total of 158 patients met our inclusion criteria. The median age was 35 years (interquartile range [IQR]: 23-53), 86.1% were male, and 60.1% sustained blunt trauma. Most patients suffered severe injuries with a median injury severity score of 27 (IQR: 18-38). The sensitivity, specificity, PPV, NPV, and accuracy of FAST for identifying intra-abdominal hemorrhage were 66.0%, 84.8%, 68.6%, 83.2%, and 78.5%, respectively. Among the 107 patients with a negative FAST, 22 (20.6%) underwent DPA, which was positive in 5 patients. CONCLUSIONS: FAST can be utilized in the diagnostic workup of trauma patients after RT. In patients with a positive FAST, exploratory laparotomy is warranted, whereas other diagnostic adjuncts such as DPA or mandatory abdominal exploration may be considered in patients with a negative FAST.

Disseminated cutaneous gout: a rare manifestation of a common disease.

Disseminated cutaneous gout is a rare atypical cutaneous manifestation of gout in which widespread dermal and subcutaneous tophi develop at extra-articular body sites. Given the lack of joint involvement that is typically a feature in tophaceous gout, the diagnosis may not be initially suspected. We present the case of a 50-year-old Hispanic man with poorly controlled gout who was evaluated for several years of firm papulonodules over the trunk and upper and lower extremities, sparing the joints; histopathology confirmed, the diagnosis of disseminated cutaneous gout. Per our literature review, disseminated cutaneous gout presents with polymorphous papules and nodules that can mimic other, more common cutaneous diseases. There is a preponderance of cases in males, Asians, and patients with longstanding gout. The lower extremities are involved in nearly all reports. Uric acid-lowering therapy with allopurinol has been reported to decrease the size and number of lesions in a minority of treated patients.

Microfluidic fabrication of vesicles with hybrid lipid/nanoparticle bilayer membranes.

Hybrid lipid/nanoparticle membranes are suitable model systems both to study the complex interactions between nanoparticles and biological membranes, and to demonstrate technological concepts in cellular sensing and drug delivery. Unfortunately, embedding nanoparticles into the bilayer membrane of lipid vesicles is challenging due to the poor control over the vesicle fabrication process of conventional methodologies and the fragility of the modified lipid bilayer assembly. Here, the utility of water-in-oil-in-water double emulsion drops with ultrathin oil shells as templates to form vesicles with hybrid lipid/nanoparticle membranes is reported. Moreover, upon bilayer formation, which occurs through dewetting of the oil solvent from the double emulsion drops, a phase separation is observed in the vesicle membrane, with solid-like nanoparticle-rich microdomains segregated into a continuous fluid-like nanoparticle-poor phase. This phase coexistence evidences the complex nature of the interactions between nanoparticles and lipid membranes. In this context, this microfluidic-assisted fabrication strategy may play a crucial role in thoroughly understanding such interactions given the uniform membrane properties of the resulting productions. Furthermore, the high encapsulation efficiency of both the vesicle membrane and core endows these vesicles with great potential for sensing applications and drug delivery.

Conformational Dynamics of a Single Protein Monitored for 24 h at Video Rate.

We use plasmon rulers to follow the conformational dynamics of a single protein for up to 24 h at a video rate. The plasmon ruler consists of two gold nanospheres connected by a single protein linker. In our experiment, we follow the dynamics of the molecular chaperone heat shock protein 90 (Hsp90), which is known to show "open" and "closed" conformations. Our measurements confirm the previously known conformational dynamics with transition times in the second to minute time scale and reveals new dynamics on the time scale of minutes to hours. Plasmon rulers thus extend the observation bandwidth 3-4 orders of magnitude with respect to single-molecule fluorescence resonance energy transfer and enable the study of molecular dynamics with unprecedented precision.

Plasmonic Nanosensors Reveal a Height Dependence of MinDE Protein Oscillations on Membrane Features.

Single-particle plasmon spectroscopy has become a standard technique to detect and quantify the presence of unlabeled macromolecules. Here, we extend this method to determine their exact distance from the plasmon sensors with sub-nanometer resolution by systematically varying the sensing range into the surrounding by adjusting the size of the plasmonic nanoparticles. We improved current single-particle plasmon spectroscopy to record continuously for hours the scattering spectra of thousands of nanoparticles of different sizes simultaneously with 1.8 s time resolution. We apply this technique to study the interaction dynamics of bacterial Min proteins with supported lipid membranes of different composition. Our experiments reveal a surprisingly flexible operating mode of the Min proteins: In the presence of cardiolipin and membrane curvature induced by nanoparticles, the protein oscillation occurs on top of a stationary MinD patch. Our results reveal the need to consider membrane composition and local curvature as important parameters to quantitatively understand the Min protein system and could be extrapolated to other macromolecular systems. Our label-free method is generally easily implementable and well suited to measure distances of interacting biological macromolecules.

Synthesis of Au-CdS@CdSe Hybrid Nanoparticles with a Highly Reactive Gold Domain.

We propose a novel route to synthesize semiconductor-gold hybrid nanoparticles directly in water, resulting in much larger gold domains than previous protocols (up to 50 nm) with very reactive surfaces which allow further functionalization. This method advances the possibility of self-assembly into complex structures with catalytic activity toward the reduction of nitro compounds by hydrides. The large size of these gold domains in hybrid particles supports efficient light scattering at the plasmon resonance frequency, making such structures attractive for single-particle studies.

Plasmonic nanosensors for simultaneous quantification of multiple protein-protein binding affinities.

Most of current techniques used for the quantification of protein-protein interactions require the analysis of one pair of binding partners at a time. Herein we present a label-free, simple, fast, and cost-effective route to characterize binding affinities between multiple macromolecular partners simultaneously, using optical dark-field spectroscopy and individual protein-functionalized gold nanorods as sensing elements. Our NanoSPR method could easily become a simple and standard tool in biological, biochemical, and medical laboratories.

Control by potassium of the size distribution of Escherichia coli FtsZ polymers is independent of GTPase activity.

The influence of potassium content (at neutral pH and millimolar Mg(2+)) on the size distribution of FtsZ polymers formed in the presence of constantly replenished GTP under steady-state conditions was studied by a combination of biophysical methods. The size of the GTP-FtsZ polymers decreased with lower potassium concentration, in contrast with the increase in the mass of the GDP-FtsZ oligomers, whereas no effect was observed on FtsZ GTPase activity and critical concentration of polymerization. Remarkably, the concerted formation of a narrow size distribution of GTP-FtsZ polymers previously observed at high salt concentration was maintained in all KCl concentrations tested. Polymers induced with guanosine 5'-(α,ß-methylene)triphosphate, a slowly hydrolyzable analog of GTP, became larger and polydisperse as the potassium concentration was decreased. Our results suggest that the potassium dependence of the GTP-FtsZ polymer size may be related to changes in the subunit turnover rate that are independent of the GTP hydrolysis rate. The formation of a narrow size distribution of FtsZ polymers under very different solution conditions indicates that it is an inherent feature of FtsZ, not observed in other filament-forming proteins, with potential implications in the structural organization of the functional Z-ring.

Optical dark-field spectroscopy of single plasmonic nanoparticles for molecular biosciences.

An ideal sensor capable of quantifying analytes in minuscule sample volumes represents a significant technological advancement. Plasmonic nanoparticles integrated with optical dark-field spectroscopy have reached this capability, demonstrating versatility and expanding applicability across in vitro and in vivo subjects. This review underscores the applicability of optical dark-field spectroscopy with single plasmonic nanoparticles to elucidate a wide range of biomolecular characteristics, including binding constants, molecular dynamics, distances, and forces, as well as recording cell communication signals. Perspectives highlight the potential for the development of implantable nanosensors for metabolite detection in animal models, illustrating the technique's efficacy without the need for labeling molecules. In summary, this review aims to consolidate knowledge of this adaptable and robust technique for decoding molecular biological phenomena within the nano- and bio-scientific community.

Assessment of the Impact of Humic Acids on Intestinal Microbiota, Gut Integrity, Ileum Morphometry, and Cellular Immunity of Turkey Poults Fed an Aflatoxin B1-Contaminated Diet.

A recent study published data on the growth performance, relative weights of the organs of the gastrointestinal tract, liver histology, serum biochemistry, and hematological parameters for turkey poults fed an experimental diet contaminated with aflatoxin B1 (AFB1) and humic acids (HA) extracted from vermicompost. The negative effects of AFB1 (250 ng AFB1/g of feed) were significantly reduced by HA supplementation (0.25% w/w), suggesting that HA might be utilized to ameliorate the negative impact of AFB1 from contaminated diets. The present study shows the results of the remaining variables, as an extension of a previously published work which aimed to evaluate the impact of HA on the intestinal microbiota, gut integrity, ileum morphometry, and cellular immunity of turkey poults fed an AFB1-contaminated diet. For this objective, five equal groups of 1-day-old female Nicholas-700 turkey poults were randomly assigned to the following treatments: negative control (basal diet), positive control (basal diet + 250 ng AFB1/g), HA (basal diet + 0.25% HA), HA + AFB1 (basal diet + 0.25% HA + 250 ng AFB1/g), and Zeolite (basal diet + 0.25% zeolite + 250 ng AFB1/g). In the experiment, seven replicates of ten poults each were used per treatment (n = 70). In general, HA supplementation with or without the presence of AFB1 showed a significant increase (p < 0.05) in the number of beneficial butyric acid producers, ileum villi height, and ileum total area, and a significant reduction in serum levels of fluorescein isothiocyanate-dextran (FITC-d), a marker of intestinal integrity. In contrast, poults fed with AFB1 showed a significant increase in Proteobacteria and lower numbers of beneficial bacteria, clearly suggesting gut dysbacteriosis. Moreover, poults supplemented with AFB1 displayed the lowest morphometric parameters and the highest intestinal permeability. Furthermore, poults in the negative and positive control treatments had the lowest cutaneous basophil hypersensitivity response. These findings suggest that HA supplementation enhanced intestinal integrity (shape and permeability), cellular immune response, and healthier gut microbiota composition, even in the presence of dietary exposure to AFB1. These results complement those of the previously published study, suggesting that HA may be a viable dietary intervention to improve gut health and immunity in turkey poults during aflatoxicosis.

Effect of the Addition of Humic Substances on Morphometric Analysis and Number of Goblet Cells in the Intestinal Mucosa of Broiler Chickens.

The mechanisms of action of humic substances (HS) as growth promoters in poultry are unknown. In this study, the productive performance, histology, and number of goblet cells (GC) in the intestinal villi of broilers under steady-state digestive conditions and under abrupt changes in diet with the addition of HS was evaluated. Broilers housed individually were offered three treatments from 14−28 days: 1 = diet with white corn/soybean meal, without growth promoter antibiotics (nonGPA); 2 = with GPA (GPA); and 3 = with 0.3% HS. At day 28, two diets were suddenly introduced: (A) white corn/soybean meal plus dried distillers' grains with solubles (DDGS); and (B) white/blue corn/soybean meal/DDGS, keeping the three original treatments. Diets A and B were also exchanged on day 37. FCR was lower with GPA and HS compared to nonGPA from 14−38 days (p < 0.05); at day 28, under steady-state digestive conditions, HS had a similar effect to GPA on the histology and GC number in the jejunum villi. The number of GC in the jejunum of HS-fed broilers on days 29 and 38, after diet changes, behaves similarly to that of AGP-fed broilers (p > 0.05). HS appears to strengthen the mucosal protection of the epithelium of the intestine.

Humic Acids Preparation, Characterization, and Their Potential Adsorption Capacity for Aflatoxin B1 in an In Vitro Poultry Digestive Model.

Vermicompost was used for humic acid (HA) preparation, and the adsorption of aflatoxin B1 (AFB1) was investigated. Two forms of HA were evaluated, natural HA and sodium-free HA (SFHA). As a reference, a non-commercial zeolitic material was employed. The adsorbents were characterized by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), energy-dispersive X-ray spectroscopy (EDS), zeta potential (ζ-potential), scanning electron microscopy (SEM), and point of zero charge (pHpzc). The adsorbent capacity of the materials when added to an AFB1-contaminated diet (100 µg AFB1/kg) was evaluated using an in vitro model that simulates the digestive tract of chickens. Characterization results revealed the primary functional groups in HA and SFHA were carboxyl and phenol. Furthermore, adsorbents have a highly negative ζ-potential at the three simulated pH values. Therefore, it appears the main influencing factors for AFB1 adsorption are electrostatic interactions and hydrogen bonding. Moreover, the bioavailability of AFB1 in the intestinal section was dramatically decreased when sorbents were added to the diet (0.2%, w/w). The highest AFB1 adsorption percentages using HA and SFHA were 97.6% and 99.7%, respectively. The zeolitic material had a considerable adsorption (81.5%). From these results, it can be concluded that HA and SFHA from vermicompost could be used as potential adsorbents to remove AFB1 from contaminated feeds.

Evaluation of the efficacy of humic acids to counteract the toxic effects of aflatoxin B1 in turkey poults.

This study aims to evaluate the efficacy of humic acid (HA) from worm compost as an adsorbent for aflatoxin B1 (AFB1) in turkey poults. The experiment involved the inclusion of 0.25% (w/w) HA in the diet of turkey poults consuming aflatoxin-contaminated feed (250 ng AFB1/g). A total of 350 1-day-old female Nicholas-700 turkey poults were randomly allocated to five equal groups: negative control (basal diet); positive control (basal diet + 250 ng AFB1/g; HA (basal diet + 0.25% HA); HA + AFB1 (basal diet + HA + 250 ng AFB1/g); and zeolite + AFB1 (basal diet + 0.25% zeolite + 250 ng AFB1/g). Each group had seven replicates of 10 poults (n = 70). The impact of HA addition was evaluated in terms of performance parameters, relative organ weights, liver histological lesions, and serum biochemical and hematological constituents. In general, the addition of HA improved body weight (BW), body weight gain (BWG), and feed conversion rate (FCR). Furthermore, HA effectively mitigated the toxic effects caused by AFB1 in the majority of the analyzed variables. The results indicated that HA effectively counteracted the AFB1-induced toxic effects in turkey poults. Based on these findings, it can be concluded that HA is capable of removing AFB1 from the contaminated diet.

Corrigendum: Evaluation of the efficacy of humic acids to counteract the toxic effects of aflatoxin B1 in turkey poults.

[This corrects the article DOI: 10.3389/fvets.2023.1276754.].

Mg(2+)-linked self-assembly of FtsZ in the presence of GTP or a GTP analogue involves the concerted formation of a narrow size distribution of oligomeric species.

The assembly of the bacterial cell division FtsZ protein in the presence of constantly replenished GTP was studied as a function of Mg(2+) concentration (at neutral pH and 0.5 M potassium) under steady-state conditions by sedimentation velocity, concentration-gradient light scattering, fluorescence correlation spectroscopy, and dynamic light scattering. Sedimentation velocity measurements confirmed previous results indicating cooperative appearance of a narrow size distribution of finite oligomers with increasing protein concentration. The concentration dependence of light scattering and diffusion coefficients independently verified the cooperative appearance of a narrow distribution of high molecular weight oligomers, and in addition provided a measurement of the average size of these species, which corresponds to 100 ± 20 FtsZ protomers at millimolar Mg(2+) concentration. Parallel experiments on solutions containing guanosine-5'-[(α,ß)-methyleno]triphosphate, sodium salt (GMPCPP), a slowly hydrolyzable analogue of GTP, in place of GTP, likewise indicated the concerted formation of a narrow size distribution of fibrillar oligomers with a larger average mass (corresponding to 160 ± 20 FtsZ monomers). The closely similar behavior of FtsZ in the presence of both GTP and GMPCPP suggests that the observations reflect equilibrium rather than nonequilibrium steady-state properties of both solutions and exhibit parallel manifestations of a common association scheme.

Effects of humic acids on the recovery of different bacterial strains in an in vitro chicken digestive model.

Humic acids (HA) have been evaluated as growth promoters in poultry, but their effects on the gut microbiota remains controversial using in vitro and in vivo models. The objective of this study was to determine the effect of HA extracted from a wormcompost on the recovery of bacteria: Salmonella Enteritidis (S. Enteritidis), Escherichia coli (E. coli), Clostridium perfringens (C. perfringens), Bacillus subtilis (B. subtilis) and Lactobacillus salivarius (L. salivarius) using an in vitro chicken digestive system. Independent in vitro trials were run for each bacteria using six treatments: 1) Negative control with no bacteria added (Control-), 2) Positive control added with bacteria (Control+), 3) 0.1% HA + bacteria, 4) 0.2% HA + bacteria, 5) 0.5% HA + bacteria and 6) 1% HA + bacteria. Data was subjected to analysis of variance and linear regression. In the crop, S. Enteritidis was lower, C. perfringes and B. subtilis were not affected by HA, while E. coli and L. salivarius were higher at 0.5 and 1% HA inclusion (P ≤ 0.0001). In the proventriculus, S. Enteritidis, E. coli and B. subtilis were higher at 0.5 and 1% HA inclusion (P ≤ 0.0001); C. perfringens and L. salivarius were not affected by HA. In intestine, significant increases of all bacteria strains were observed (P ≤ 0.0001). In conclusion, the results suggests that HA can be used as prebiotic, but their mechanisms of action to stimulate the growth of gut bacteria remains to be elucidated.

Tunable gold nanorod/NAO conjugates for selective drug delivery in mitochondria-targeted cancer therapy.

Nonyl acridine orange (NAO) is a lipophilic and positively charged molecule widely used as a mitochondrial fluorescent probe. NAO is cytotoxic at micromolar concentration and might be potentially used as a mitochondria-targeted drug for cancer therapy. However, the use of NAO under in vivo conditions would be compromised by the unspecific interactions with off-target cells and negatively charged proteins present in the bloodstream. To tackle this limitation, we have synthesized NAO analogues carrying an imidazole group for their specific binding to nitrilotriacetic (NTA) functionalized gold nanorods (AuNRs). We demonstrate that AuNRs provide 104 binding sites and a controlled delivery under acidic conditions. Upon incubation with mouse embryonic fibroblasts, the endosomal acidic environment releases the NAO analogues from AuNRs, as visualized through the staining of the mitochondrial network. The addition of the monoclonal antibody Cetuximab to the conjugates enhanced their uptake within lung cancer cells and the conjugates were cytotoxic at subnanomolar concentrations (c50 ≈ 0.06 nM). Moreover, the specific interactions of Cetuximab with the epidermal growth factor receptor (EGFR) provided a specific targeting of EGFR-expressing lung cancer cells. After intravenous administration in patient-derived xenografts (PDX) mouse models, the conjugates reduced the progression of EGFR-positive tumors. Overall, the NAO-AuNRs provide a promising strategy to realize membrane mitochondria-targeted conjugates for lung cancer therapy.

Whole-Genome Sequence and Interaction Analysis in the Production of Six Enzymes From the Three Bacillus Strains Present in a Commercial Direct-Fed Microbial (Norum™) Using a Bliss Independence Test.

The three Bacillus strains present in Norum™ were initially selected by their excellent to good relative enzyme activity (REA) production score for amylase, protease, lipase, phytase, cellulase, ß-glucanase, and xylanase. Further studies confirmed that the three isolates also showed an antibacterial activity, Gram-positive and Gram-negative poultry pathogens. Norum™ (Eco-Bio/Euxxis Bioscience LLC) is a Bacillus spore direct-fed microbial (DFM). The Bacillus isolates were screened and selected based on in vitro enzyme production profiles. Moreover, in chickens fed high non-starch polysaccharides, this DFM demonstrated to reduce digesta viscosity, bacterial translocation, increase performance, bone mineralization, and balance the intestinal microbiota. In the present study, we present the whole-genome sequence of each of the three isolates in Norum™, as well as the synergistic, additive, or antagonistic effects on the enzyme production behavior of the three Bacillus strains and their combinations when grown together vs. when grown individually. The whole-genome sequence identified isolate AM1002 as Bacillus subtilis (isolate 1), isolate AM0938 as Bacillus amyloliquefaciens (isolate 2), and isolate JD17 as Bacillus licheniformis (isolate 3). The three Bacillus isolates used in the present study produce different enzymes (xylanase, cellulase, phytase, lipase, protease, and ß-glucanase). However, this production was modified when two or more Bacillus strains were combined, suggesting possible synergistic, antagonistic, or additive interactions. The Bliss analysis suggested (p < 0.05) that the combination of Bacillus strains 1-2 and 1-2-3 had intermediate effects and predicted that the combination of Bacillus strains 2-3 could have better effects than the combination of all the three Bacillus strains. In summary, the current study demonstrated the need of selecting Bacillus strains based on quantitative enzyme determination and data analysis to assess the impacts of combinations to avoid antagonistic interactions that could limit treatment efficacy. These results suggest that using Bacillus strains 2-3 together could lead to a new generation of DFMs with effects superior to those already examined in Bacillus strains 1-2-3 and, therefore, a potential alternative to growth-promoting antibiotics. More research utilizing poultry models is being considered to confirm and expand the existing findings.

Diagnostic Peritoneal Aspiration Revisited: Its Diagnostic Accuracy for the Detection of Intraabdominal Hemorrhage.

BACKGROUND: The use of Focused Assessment with Sonography for Trauma (FAST) in combination with computed tomography (CT) has become the mainstay of diagnostic workup in patients with suspected intraabdominal hemorrhage (IAH). However, diagnostic peritoneal aspiration (DPA) can be an important adjunct in hemodynamically unstable patients. The aim of this study was to evaluate the utility and diagnostic accuracy of DPA in detecting IAH. METHODS: Retrospective analysis of all patients who presented to the LAC+USC Medical Center and underwent evaluation with DPA between January 2010 and December 2016. Intraoperative, CT, and autopsy findings were used as gold standards in determining the diagnostic accuracy of DPA for the detection of IAH. RESULTS: A total of 73 consecutive patients were included in the study. The median age was 42 years (interquartile range [IQR]: 25-56), median injury severity score was 29 (IQR: 21-41), and 82.2% sustained blunt trauma. The most common indications for DPA were hemodynamically unstable patients with suspected IAH and patients with return of spontaneous circulation following resuscitative thoracotomy. Overall, the positive and negative predictive values of DPA were 89.4% and 88.9%, respectively. In 14 cases (19.2%), DPA correctly identified false positive/negative FAST results. CONCLUSION: Our data suggest that DPA has high diagnostic yield for IAH. The use of DPA should be considered in unstable patients with inconclusive FAST results who cannot safely be evaluated with CT.

Single Out-of-Resonance Dielectric Nanoparticles as Molecular Sensors.

Light scattering from single nanoparticles and nanostructures is a commonly used readout method for nanosensors. Increasing the spectral sensitivity of resonant nanosensors to changes in their local surrounding has been the focus of many studies. Switching from spectral to intensity monitoring allows one to investigate nonresonant or out-of-resonance dielectric nanoparticles. Here, we systematically compared such dielectric silica nanoparticles with plasmonic gold nanorods by deriving analytical expressions and by performing experiments. The experiments show a similar sensitivity for the detection of an adsorbate layer for both particle types, which is in good agreement with theory. The flat spectral response of dielectric silica nanoparticles simplifies the choice of illumination wavelength. Furthermore, such dielectric nanoparticles can be made from many oxides, polymers, and even biological assemblies, broadening the choice of materials for the nanosensor.