Muscle protein catabolism and splanchnic arginine consumption drive arginine dysregulation during Pseudomonas Aeruginosa induced early acute sepsis in swine.

Human sepsis is characterized by increased protein breakdown and changes in arginine and citrulline metabolism. However, it is unclear whether this is caused by changes in transorgan metabolism. We therefore studied in a Pseudomonas aeruginosa induced pig sepsis model the changes in protein and arginine related metabolism on whole body (Wb) and transorgan level. We studied 22 conscious pigs for 18 hours during sepsis, induced by infusing live bacteria (Pseudomonas aeruginosa) or after placebo infusion (control). We used stable isotope tracers to measure Wb and skeletal muscle protein synthesis and breakdown, as well as Wb, splanchnic, skeletal muscle, hepatic and portal drained viscera (PDV) arginine and citrulline disposal and production rates. During sepsis, arginine Wb production (p=0.0146), skeletal muscle release (p=0.0035) and liver arginine uptake were elevated (p=0.0031). Wb de novo arginine synthesis, citrulline production, and transorgan PDV release of citrulline, glutamine and arginine did not differ between sepsis and controls. However, Wb (p<0.0001) and muscle (p<0.001) protein breakdown were increased, suggesting that the enhanced arginine production is predominantly derived from muscle breakdown in sepsis. In conclusion, live-bacterium sepsis increases muscle arginine release and liver uptake, mirroring previous pig endotoxemia studies. In contrast to observations in humans, acute live-bacterium sepsis in pigs does not change citrulline production or arterial arginine concentration. We therefore conclude that the arginine dysregulation observed in human sepsis is possibly initiated by enhanced protein catabolism and splanchnic arginine catabolism, while decreased arterial arginine concentration and citrulline metabolism may require more time to fully manifest in patients.

A randomized, triple-blinded, placebo-controlled clinical trial evaluating immune responses of Typhim Vi and PPSV23 vaccines in healthy adults: The PREP study.

Rapid and early identification of emergent infections is essential for delivering prompt clinical care. To advance the development of algorithms for the clinical management of infection identification, we performed a vaccination clinical trial to investigate the potential of using vaccination as a model for studying mild inflammation responses associated with different infections (NCT05346302). We collected data at various time points over 4 weeks from blood samples, wearable devices, and questionnaires. Following a 2-week baseline period, 210 healthy participants, aged 18-40 years, were administered either a Pneumococcal Polysaccharide vaccine (PPSV23), Typhoid Vi Polysaccharide vaccine (Typhim Vi), or placebo. In longitudinal analyses of blood biomarkers, we found that CRP was significantly higher at 2 days post-vaccination, whereas basophils, IL-10, IL-12p40, and MIG were significantly higher at 7 days post-vaccination in the PPSV23 group compared to both other groups (all p < 0.05). MIP-1ß was significantly lower in the PPSV23 group than in the placebo group, while monocytes and MPV were significantly lower in the Typhim Vi group than in the placebo group at 7 days post-vaccination (all p < 0.05). The PPSV3 group showed a higher inflammatory profile, suggesting that PPSV23 induces a stronger immune response compared to Typhim Vi. The distinct immune responses induced by the two vaccines indicate the potential for utilizing vaccines as models for studying inflammation responses associated with different infectious pathogens.

Selection indices for residual feed intake derived from milk spectra.

Improving production efficiency and minimizing the environmental impact of dairy farming are 2 important goals of the dairy industry. Achieving these objectives requires improving the feed-to-milk conversion efficiency. One way to achieve this goal is through genetic selection. However, measuring feed efficiency in commercial herds is currently not feasible. As such, we conducted a study to evaluate the genetic accuracy of various selection indices derived from Fourier transform mid-infrared (FTIR)-spectra or milk composition. We use 7,793 weekly records on 537 genotyped cows (78,964 SNPs), with information on residual feed intake (RFI), and FTIR-spectra. We fitted various types of selection indexes using the complete FTIR-spectra of milk samples. The estimated heritability of RFI was 0.12 ± 0.02. The accuracy of indirect selection using the FTIR-spectra was maximized using a principal components selection index (0.16 ± 0.07), followed by a Lasso-type penalized selection index (0.14 ± 0.06). We determined that an index based on milk spectral data recorded on ~25 daughters produced a progeny average with an accuracy comparable to direct phenotypic selection for RFI. We conclude that indirect selection for RFI using FTIR-spectra data can be effective for sires with progeny; however, future studies with a larger sample size are needed to validate these results.

Impact of health literacy on pregnancy outcomes in socioeconomically disadvantaged and ethnic minority populations: A scoping review.

BACKGROUND: Health literacy, influenced by sociodemographic characteristics such as ethnicity, economic means and societal factors, affects the ways in which pregnant women maintain their health; this in turn may increase risk of adverse pregnancy outcomes. OBJECTIVE: To explore what is known about the impact of personal health literacy on prevention of stillbirth and related adverse outcomes in pregnant women of low socioeconomic status or from ethnic minority backgrounds. SEARCH STRATEGY: MEDLINE, CINAHL, PsychINFO, and CENTRAL were searched as well as reference lists of included studies and gray literature. SELECTION CRITERIA: Included studies focused on personal health literacy and stillbirth prevention in women from low socioeconomic or ethnic minority backgrounds in the perinatal period. DATA COLLECTION AND ANALYSIS: A meta-summary approach was adopted for qualitative, observational, descriptive, and audit studies. Findings of intervention studies were extracted, and meta-analyses were conducted where possible. The primary outcome was stillbirth; maternal mortality and neonatal mortality were secondary outcomes. MAIN RESULTS: Forty-one studies were included from diverse geographical settings. The meta-summary synthesized five abstracted statements. These recognized lower personal health literacy and greater difficulty interacting with healthcare services in the studied populations, primarily as the result of limited health knowledge, lack of positive perception towards health services, language barriers, illiteracy, and relying on friends or family members for health information. Meta-analysis of intervention studies revealed no association between current interventions that aimed to increase personal health literacy and the risk of stillbirth (relative risk [RR] 1.04, 95% confidence interval [CI] 0.96-1.12), neonatal mortality (RR 0.88, 95% CI 0.75-1.03), and maternal mortality (RR 0.87, 95% CI 0.63-1.22). CONCLUSIONS: Various factors suggest lower personal health literacy in women of low socioeconomic status or ethnic minority, which can increase the risk of stillbirth. However, this review identified no significant impact of current health education interventions on the risk of stillbirth, or neonatal or maternal mortality. Although not directly measured, the health education interventions were anticipated to increase personal health literacy. Further research on the topic of this scoping review is warranted, particularly in lower-resource settings and regarding the potential role of e-literacy and organizational health literacy to improve pregnancy outcomes. To address deficits in health literacy, efforts must be made to provide pregnant women with health information in novel, accessible ways.

Design of the electron cyclotron resonance (ECR) plasma source for the space plasma environment research facility.

The Space Plasma Environment Research Facility (SPERF) was built in Harbin to study the three-dimensional magnetic reconnection and wave-particle interactions relevant to space physics in laboratory settings. A 2.45 GHz Electron Cyclotron Resonance (ECR) plasma source is adopted in the device to simulate the Earth's magnetosphere and achieve the scientific goals. In this paper, the design of the ECR plasma source is presented. The structures of the microwave source, the microwave transfer system, and the antenna are introduced. Additionally, the resonant surfaces are computed to predict the locations of microwave absorption. The absorption mechanisms of the microwave in the SPERF are also discussed. The discharge experiment demonstrates the utility of the ECR source in simulating the Earth's magnetosphere. The successful operation of the source indicates that the ECR discharge is a powerful tool for creating a plasma environment in a large plasma experimental device.

[GDF-15 and the risk of bleeding in patients with stable CAD receiving multicomponent antithrombotic therapy: the results of the prospective REGATA register].

AIM: To evaluate the prognostic value of GDF-15 in relation the development of bleeding and events in stable CAD patients, receiving combined antithrombotic therapy. MATERIALS AND METHODS: The data was obtained from the prospective registry REGATA, 343 CAD patients (249 males), median age 68 [IQR 62; 75] years) were enrolled. Patients with sinus rhythm and concomitant PAD received acetylsalicylic acid in combination with rivaroxaban 2.5 mg bid (31.8%) or clopidogrel (24.8%). Other 43.4% with concomitant atrial fibrillation (AF) received direct oral anticoagulants in combination with antiplatelet therapy after elective percutaneous coronary interventions. Median follow-up was 12 months [IQR 9.0; 18.0]. The safety end point was major and clinically relevant bleedings (type 2-5) according to the BARC classification. Plasma samples for GDF-15 identification were taken at the inclusion and analyzed using ELISA assay. RESULTS: Frequency of BARC 2-5 bleedings was 16% (BARC 2 - 46; BARC 3 - 9; BARC 4-5 - 0), median GDF-15 level was 1185.0 pg/ml [850.0; 1680.0]. In patients with AF and concomitant MFA, the level of GDF-15 was significantly higher than in the subgroups of patients with only AF or MFA (p=0.0022). According to the quintile analysis, GDF-15 values in the top three quintiles of distribution (cut-off value >943 pg/ml) were associated with higher frequency of bleeding events: 23.2% versus 5.1%; p=0.0001. The multivariable logistic regression model demonstrated that bleeding events were independently associated with GDF-15 level>943 pg/ml (OR 2.65, 95% CI 1.11-6.30; p=0.0275), AF (OR 2.61, 95% CI 1.41-4.83; p=0.0023) and chronic kidney disease (OR 1.92, 95% CI 1.03-3.60; p=0.0401). Clinical factors determining the risk of bleeding events also determined a GDF-15 elevation. CONCLUSION: Assessment of GDF-15 level may improve bleeding risk stratification in CAD patients with concomitant AF and/or PAD receiving combined antithrombotic therapy.

Changes in donor vessel physiology following coronary computed tomography angiography guided chronic total occlusion percutaneous coronary intervention: insights from computed tomography fractional flow reserve and artificial intelligence-guided ischemia model.

Donor vessel fractional flow reserve (FFR) usually increases following successful chronic total occlusion (CTO) percutaneous coronary intervention, as documented by pressure wires. In this case, donor vessel physiology changes were assessed using FFR derived from coronary computed tomography angiography (CCTA) and an artificial Intelligence-guided quantitative CCTA ischemia model in combination with pressure wire-based FFR.

The L-lactate dehydrogenases of Pseudomonas aeruginosa are conditionally regulated but both contribute to survival during macrophage infection.

Pseudomonas aeruginosa is an opportunistic pathogen that thrives in environments associated with human activity, including soil and water altered by agriculture or pollution. Because L-lactate is a significant product of plant and animal metabolism, it can serve as a carbon source for P. aeruginosa in the diverse settings that it inhabits. In this study, we evaluate the production and use of two redundant P. aeruginosa L-lactate dehydrogenases, termed LldD and LldA. We confirm that the protein LldR represses lldD and identify a new transcription factor, called LldS, that activates lldA; these distinct regulators and the genomic contexts of lldD and lldA contribute to their differential expression. We demonstrate that the lldD and lldA genes are conditionally controlled in response to lactate isomers as well as to glycolate and ɑ-hydroxybutyrate, which, like lactate, are ɑ-hydroxycarboxylates. We also show that lldA is induced when iron availability is low. Our examination of lldD and lldA expression across depth in biofilms indicates a complex pattern that is consistent with the effects of glycolate production, iron availability, and cross-regulation on enzyme preference. Finally, macrophage infection assays reveal that both lldD and lldA contribute to persistence within host cells, underscoring the potential role of L-lactate as a carbon source during P. aeruginosa-eukaryote interactions. Together, these findings help us understand the metabolism of a key resource that may promote P. aeruginosa's success as a resident of contaminated environments and animal hosts.IMPORTANCEPseudomonas aeruginosa is a major cause of lung infections in people with cystic fibrosis, of hospital-acquired infections, and of wound infections. It consumes L-lactate, which is found at substantial levels in human blood and tissues. In this study, we investigated the spatial regulation of two redundant enzymes, called LldD and LldA, which enable L-lactate metabolism in P. aeruginosa biofilms. We uncovered mechanisms and identified compounds that control the preference of P. aeruginosa for LldD versus LldA. We also showed that both enzymes contribute to its ability to survive within macrophages, a behavior that is thought to augment the chronicity and recalcitrance of infections. Our findings shed light on a key metabolic strategy used by P. aeruginosa and have the potential to inform the development of therapies targeting bacterial metabolism during infection.

External validation of the JR-CTO score in retrograde chronic total occlusion intervention: from the PROGRESS-CTO registry.

In complex chronic total occlusion (CTO) percutaneous coronary interventions (PCI), a retrograde crossing strategy is often necessary. Recently, the Japanese retrograde (JR) CTO score was developed using a simple 4-item tool. This score showed a good performance in predicting guidewire crossing failure in patients undergoing primary retrograde CTO PCI. We evaluated the JR-CTO score's performance in patients treated at 44 centers between 2013 and 2024 as part of the Prospective Global Registry for the Study of CTO Intervention (PROGRESS-CTO). In an independent cohort, although the JR-CTO score showed an association with crossing and technical failure, its predictive ability for both outcomes was modest.

Voluntary co-contraction of ankle muscles alters motor unit discharge characteristics and reduces estimates of persistent inward currents.

Motoneuronal persistent inward currents (PICs) are facilitated by neuromodulatory inputs but are highly sensitive to local inhibitory circuits. Estimates of PICs are reduced by group Ia reciprocal inhibition, and increased with the diffuse actions of neuromodulators released during remote muscle contraction. However, it remains unknown how motoneurons function in the presence of simultaneous excitatory and inhibitory commands. To probe this topic, we investigated motor unit discharge patterns and estimated PICs during voluntary co-contraction of ankle muscles, which simultaneously demands the contraction of agonist-antagonist pairs. Twenty participants performed triangular ramps of both co-contraction (simultaneous dorsiflexion and plantar flexion) and isometric dorsiflexion to a peak of 30% of their maximum muscle activity from a maximal voluntary contraction. Motor unit spike trains were decomposed from high-density surface EMG activity recorded from tibialis anterior using blind source separation algorithms. Voluntary co-contraction altered motor unit discharge rate characteristics. Discharge rate at recruitment and peak discharge rate were modestly reduced (∼6% change; P < 0.001; d = 0.22) and increased (∼2% change; P = 0.001, d = -0.19), respectively, in the entire dataset but no changes were observed when motor units were tracked across conditions. The largest effects during co-contraction were that estimates of PICs (ΔF) were reduced by ∼20% (4.47 vs. 5.57 pulses per second during isometric dorsiflexion; P < 0.001, d = 0.641). These findings suggest that, during voluntary co-contraction, the inhibitory input from the antagonist muscle overcomes the additional excitatory and neuromodulatory drive that may occur due to the co-contraction of the antagonist muscle, which constrains PIC behaviour. KEY POINTS: Voluntary co-contraction is a unique motor behaviour that concurrently provides excitatory and inhibitory synaptic input to motoneurons. Co-contraction of agonist-antagonist pairs alters agonist motor unit discharge characteristics, consistent with reductions in persistent inward current magnitude.

A flexible beamline combining XUV attosecond pulses with few-femtosecond UV and near-infrared pulses for time-resolved experiments.

We describe a beamline where few-femtosecond ultraviolet (UV) pulses are generated and synchronized to few-cycle near-infrared (NIR) and extreme ultraviolet (XUV) attosecond pulses. The UV light is obtained via third-harmonic generation in argon or neon gas when focusing a phase-stabilized NIR driving field inside a glass cell that was designed to support high pressures for enhanced conversion efficiency. A recirculation system allows reducing the large gas consumption required for the nonlinear process. Isolated attosecond pulses are generated using the polarization gating technique, and the photon spectrometer employed to characterize the XUV radiation consists of a new design based on the combination of a spherical varied-line-space grating and a cylindrical mirror. This design allows for compactness while providing a long entrance arm for integrating different experimental chambers. The entire interferometer is built under vacuum to prevent both absorption of the XUV light and dispersion of the UV pulses, and it is actively stabilized to ensure an attosecond delay stability during experiments. This table-top source has been realized with the aim of investigating UV-induced electron dynamics in neutral states of bio-relevant molecules, but it also offers the possibility to implement a manifold of novel time-resolved experiments based on photo-ionization/excitation of gaseous and liquid targets by ultraviolet radiation. UV pump-XUV probe measurements in ethyl-iodide showcase the capabilities of the attosecond beamline.

Novel odd-chain cyclopropane fatty acids: detection in a mammalian lipidome and uptake by hepatosplanchnic tissues.

Microbe-produced molecules (xenometabolites) found in foods or produced by gut microbiota are increasingly implicated in microbe-microbe and microbe-host communication. Xenolipids, in particular, are a class of metabolites for which the full catalog remains to be elaborated in mammalian systems. We and others have observed that cis-3,4-methylene-heptanoylcarnitine (cis-3,4-MHC) is a lipid derivative that is one of the most abundant medium-chain acylcarnitines in human blood, hypothesized to be a product of incomplete ß-oxidation of one or more "odd-chain" long-chain cyclopropane fatty acids (CpFAs). We deduced two possible candidates, cis-11,12-methylene-pentadecanoic acid (cis-11,12-MPD) and cis-13,14-methylene-heptadecanoic acid (cis-13,14 MHD). Authentic standards were synthesized: cis-11-pentadecenoic acid and cis-13-heptadecenoic acid were generated (using Jones reagent) from cis-11-pentadecene-1-ol and cis-13-heptadecene-1-ol, respectively, and these were converted to CpFAs via a reaction involving diiodomethane. Using these standards in mass spectrometry analyses, we determined presence/absence of cis-11,12-MPD and cis-13,14 MHD in archived piglet biospecimens. Both CpFAs were detected in rectal contents of sow and soy-fed piglets. Archived mass spectra were analyzed post hoc from a second, independent study that used tissue-specific catheterization to monitor net metabolite flux in growing pigs. This confirmed the presence of both CpFAs in plasma, and revealed a significant net uptake of the odd-chain CpFAs across the splanchnic tissue bed and liver. The results confirm that the novel xenolipids cis-11,12-MPD and cis-13,14 MHD can be components of the mammalian lipidome, and are viable candidate precursors of cis-3,4-MHC produced from partial ß-oxidation in liver or other tissues.

Virtual crossmatching reveals upregulation of placental HLA-Class II in chronic histiocytic intervillositis.

Chronic histiocytic intervillositis (CHI) is a recurrent placental lesion where maternal macrophages infiltrate the intervillous space. Its cause is unknown, though due to similarities to rejected allografts one hypothesis is that CHI represents maternal-fetal rejection. Here, virtual crossmatching was applied to healthy pregnancies and those with a history of CHI. Anti-HLA antibodies, measured by Luminex, were present in slightly more controls than CHI (8/17 (47.1%) vs 5/14 (35.7%)), but there was no significant difference in levels of sensitisation or fetal specific antibodies. Quantification of immunohistochemical staining for HLA-Class II was increased in syncytiotrophoblast of placentas with CHI (Grade 0.44 [IQR 0.1-0.7]) compared to healthy controls (0.06 [IQR 0-0.2]) and subsequent pregnancies (0.13 [IQR 0-0.3]) (P = 0.0004). HLA-Class II expression was positively related both to the severity of CHI (r = 0.67) and C4d deposition (r = 0.48). There was no difference in overall C4d and HLA-Class I immunostaining. Though increased anti-HLA antibodies were not evident in CHI, increased expression of HLA-Class II at the maternal-fetal interface suggests that they may be relevant in its pathogenesis. Further investigation of antibodies immediately after diagnosis is warranted in a larger cohort of CHI cases to better understand the role of HLA in its pathophysiology.

Unique territorial and compartmental organization of chromosomes in the holocentric silkmoth.

The hallmarks of chromosome organization in multicellular eukaryotes are chromosome territories (CT), chromatin compartments, and insulated domains, including topologically associated domains (TADs). Yet, most of these elements of chromosome organization are derived from analyses of a limited set of model organisms, while large eukaryotic groups, including insects, remain mostly unexplored. Here we combine Hi-C, biophysical modeling, and microscopy to characterize the 3D genome architecture of the silkmoth, Bombyx mori. In contrast to other eukaryotes, B. mori chromosomes form highly separated territories. Similar to other eukaryotes, B. mori chromosomes segregate into active A and inactive B compartments, yet unlike in vertebrate systems, contacts between euchromatic A regions appear to be a strong driver of compartmentalization. Remarkably, we also identify a third compartment, called secluded "S," with a unique contact pattern. Each S region shows prominent short-range self-contacts and is remarkably devoid of contacts with the rest of the chromosome, including other S regions. Compartment S hosts a unique combination of genetic and epigenetic features, localizes towards the periphery of CTs, and shows developmental plasticity. Biophysical modeling reveals that the formation of such secluded domains requires highly localized loop extrusion within them, along with a low level of extrusion in A and B. Our Hi-C data supports predicted genome-wide and localized extrusion. Such a broad, non-uniform distribution of extruders has not been seen in other organisms. Overall, our analyses support loop extrusion in insects and highlight the evolutionary plasticity of 3D genome organization, driven by a new combination of known processes.

One-, two- and three-dimensional interlocked polymers based on hybrid inorganic-organic rotaxanes.

We report three new polymers, based on mechanically interlocked inorganic-organic rotaxanes. They are made in very mild conditions and involve pyrimidine head groups binding to copper(ii) linking units. A two-dimensional 6,3 net and a three-dimensional 10,3b net are found depending on the solvent used in the reaction.

The efficacy of prolonged antibiotic prophylaxis in total breast reconstruction with Autologous Fat Transfer (AFT): A retrospective cohort study.

BACKGROUND: Autologous fat transfer (AFT) is increasingly adopted as another total breast reconstruction option. The aim of this study was to investigate the efficacy of prolonged antibiotic treatment on the onset of surgical site infections (SSIs) in patients treated with AFT for total breast reconstruction. METHODS: This retrospective cohort study was conducted on patients who received AFT for total breast reconstruction, with antibiotic prophylaxis during their (multiple) AFT procedure(s) from 9 December 2020 to 10 October 2023. Patients were divided into 2 groups according to their prophylactic antibiotic regimen. The primary outcome was analyzed, including the cumulative incidence, the relative risk (RR), the absolute risk reduction (ARR), and the number needed to treat (NNT). For the secondary outcome, a multilevel logistic regression analysis was performed. RESULTS: Seven hundred sixty-five surgeries in 205 patients were analyzed. Six hundred twenty-four surgeries on 168 patients had perioperative antibiotic prophylaxis in combination with postoperative antibiotic prophylaxis administered (group 1). One hundred forty-one surgeries on 37 patients had only perioperative antibiotic prophylaxis administered (group 2). The RR was 0.68 (95% confidence interval [CI]; 0.14-3.31) of a SSI when receiving peri- and postoperative antibiotic prophylaxis in comparison with treatment with only perioperative prophylaxis. The ARR was 0.46% (95% CI; -1.40 to 2.32) with a NNT of 219 patients. CONCLUSION: Prolonged antibiotic prophylaxis is ineffective for patients who receive total breast reconstruction with AFT. This study showed no statistically significant difference in SSIs of the reconstructed breast after receiving prolonged antibiotic treatment in comparison with single-shot perioperative antibiotic prophylaxis.

[Puncture dilatation tracheostomy in children during transoral neurosurgical interventions]. / Punktsionnaya dilatatsionnaya trakheostomiya u detei pri transoral'nykh neirokhirurgicheskikh vmeshatel'stvakh.

Neurosurgical interventions within the ventral surface of the clivus and upper cervical vertebrae in childhood are sometimes carried out through transoral approach. In this situation, tracheostomy is safer for airway protection and mechanical ventilation compared to prolonged intubation. The world experience of percutaneous dilation tracheostomy in pediatric patients is limited due to anatomical and physiological features, such as difficult orientation in anatomical landmarks, high mobility of the trachea and small tracheal lumen. Also, the trachea easily collapses when pressed in pediatric patients that complicates safe puncture of anterior wall and can lead to perforation of posterior tracheal wall. OBJECTIVE: To describe a modified technique of video-assisted percutaneous dilation tracheostomy using additional thin guide and dilator in children of primary school age. MATERIAL AND METHODS: We considered 11 patients aged 6-12 years who underwent video-assisted percutaneous dilation tracheostomy. RESULTS: There were no perioperative complications (bleeding, false course, perforation of posterior tracheal wall). Infection of tracheostomy, fistulas or tracheal stenosis was absent. CONCLUSION: Percutaneous dilation tracheostomy may be alternative to classical surgical tracheostomy for pediatric patients. Endoscopic control and certain technical changes of percutaneous tracheostomy are necessary and provide safe manipulation. Surgery time, less trauma and minimal cosmetic defect after tracheostomy are significant advantages of this technique compared to surgical tracheostomy.

Impact of Long-term Storage in 4% Formaldehyde on Immunophenotypic Markers in Glutaraldehyde-treated Bovine Pericardium.

Bovine pericardium (BP) is widely used as a biomaterial for tissue engineering. Glutaraldehyde and formaldehyde are commonly employed in the reticulation processes to enhance the material's resistance and preservation. In this study, we assessed the impact of long-term storage in 4% formaldehyde on the quantitative expression of immunophenotypic markers in glutaraldehyde-treated BP. Histologic and immunohistochemical analyses were performed on 2 BP patches, manufactured in 2009 and 2020, respectively. Braile Biomédica provided the BP patches. Sections of BP were stained with H&E, Weigert, and picrosirius red, followed by immunolabeling for vimentin, laminin 5, collagen I, and collagen IV using a standardized protocol. Microscopic images were captured using light and polarized microscopy, and the area of the antibody signal was quantified using Image J Software. Histologic analysis showed no autolysis or significant changes in the patches. Immunohistochemical analysis revealed a diffuse distribution of collagen I and collagen IV throughout the connective tissue of the patches. The 2020 specimen exhibited higher expression levels of collagen I (21.36%) and collagen IV (24.67%) compared with the 2009 specimen (collagen I: 15.87%; collagen IV: 12.02%). Laminin did not show reactivity in either specimen. Notably, vimentin immunopositivity differed significantly between the patches, with a larger area of expression observed in the 2020 patch (54%) compared with the 2009 patch (13%). In summary, there were no substantial differences in immunophenotypic expression between the 2009 and 2020 BP patches, except for the higher vimentin expression in the 2020 BP patch.

Electro-optical effect of unpolarized light modulation in homeoplanar structures of ferroelectric and ferrielectric liquid crystals.

A clearly expressed effect of unpolarized light electro-optical modulation by homeoplanar structures of a smectic C* ferroelectric liquid crystal (FLC) and a ferrielectric liquid crystal (FerriLC) was discovered and investigated for the first time to our knowledge. This effect of electrically controlled light scattering is insensitive to the applied voltage sign, as for polymer-dispersed nematic liquid crystals (PDLCs), but the electro-optical modulation frequency reaches the kilohertz range. Occurrence conditions and essential features of the effect, as well as its physical origin, are discussed.