High Levels Of Cytotoxicity Research Articles

Immune status in women after COVID-19 living in the subarctic region

Background. T cell immunity is known to play a central role in controlling SARSCoV- 2 (severe acute respiratory syndrome-related coronavirus 2) infection, so it is critical to understand its role in recovery from COVID-19 (coronavirus disease 2019), especially in the unfavorable conditions of the North.The aim. To assess the immune status of women after COVID-19 living in the subarctic region of the Russian Federation.Materials and methods. We examined a total of 50 women aged 36–46 years, including 38 vaccinated women 6 and 12 months after recovery from COVID-19 and 12 women (control group) who had not had COVID-19 and had not been vaccinated (Arkhangelsk region). We studied leukocyte count, leukogram and lymphocyte phenotypes (CD5+, CD8+, CD10+, CD16+, CD95+).Results. The contribution of monocytes to the formation of the adaptive immune response among female residents of the subarctic region decreases in those who have had mild COVID-19 and increases in those who have had moderate COVID-19. It was found that the imbalance in the formation of the immune response after COVID-19 is formed due to innate immunity (CD16+, neutrophils (r = 0.89; p < 0.001)), affects the adaptive immunity and depends on the severity of the disease and the time since recovery. The most significant contribution to the formation of the adaptive immune response was established due to cellmediated cytotoxicity (CD8+, CD16+) and the activity of apoptotic processes (CD95+) both after 6 and 12 months and does not depend on the severity of the COVID-19. The adaptive immune response formed 6 months after COVID-19 with a high level of cell-mediated cytotoxicity and activity of apoptotic processes prevailing over lymphoproliferation persists after 12 months, which indicates a tense state of immune homeostasis.Conclusion. In the examined women who had recovered from COVID-19, cellmediated cytotoxicity (CD8+, CD16+) is associated with the activation of the monocyte system, has a prolonged effect of up to 12 months and depends on the severity of the previous COVID-19 in 66.7–90 % of cases.

Engineered extracellular vesicles with polypeptide for targeted delivery of doxorubicin against EGFR‑positive tumors.

Lack of effective tumor‑specific delivery systems remains an unmet clinical challenge for the employment of chemotherapy using cytotoxic drugs. Extracellular vesicles (EVs) have recently been investigated for their potential as an efficient drug‑delivery platform, due to their good biodistribution, biocompatibility and low immunogenicity. In the present study, the formulation of GE11 peptide‑modified EVs (GE11‑EVs) loaded with doxorubicin (Dox‑GE11‑EVs), was developed to target epidermal growth factor receptor (EGFR)‑positive tumor cells. The results obtained demonstrated that GE11‑EVs exhibited highly efficient targeting and drug delivery to EGFR‑positive tumor cells compared with non‑modified EVs. Furthermore, treatment with Dox‑GE11‑EVs led to a significantly inhibition of cell proliferation and increased apoptosis of EGFR‑positive tumor cells compared with Dox‑EVs and free Dox treatments. In addition, it was observed that treatment with either free Dox or Dox‑EVs exhibited a high level of cytotoxicity to normal cells, whereas treatment with Dox‑GE11‑EVs had only a limited effect on cell viability of normal cells. Taken together, the findings of the present study demonstrated that the engineered Dox‑GE11‑EVs can treat EGFR‑positive tumors more accurately and have higher safety than traditional tumor therapies.

Analysis of antioxidant nutrients, anti-HIV and anticancer metabolic fingerprints of Pelargonium quercifolium (L.f) L'Hér

Pelargonium quercifolium is an aromatic herb with a strong resinous scent. It is used traditionally to treat heart disease, hypertension, stress, rheumatism, combat hidden hunger, and inhibit HIV-1. The present study aimed to evaluate the toxicity, anti-HIV, antioxidant nutrients and anticancer potentials of the ethanol extract of P. quercifolium. In this study, high-resolution ultra-performance liquid chromatography-mass spectrometry (UPLC-MS), high-performance liquid chromatography with diode-array detection (HPLC-D AD), xCELLigence real-time cell analyser single plate (RTCA-SP), MTT assays and luciferase-based assay were employed to elucidate the phytochemicals, cytotoxicity, anti-HIV, antioxidant nutrients and anticancer metabolites in P. quercifolium. Results show that the characterized metabolites in P. quercifolium most of which were flavonoids, phenolic derivatives, alkaloids and coumarins could arrest cancer cell proliferation and inhibit HIV infection given the high level of cytotoxicity of the tested plant extract. It was also observed and reported for the first time, the nutrient profile of P. quercifolium is higher than most vegetables consumed as a staple food. This study underpins the potential of using anticancer and antiviral metabolites from leaf extract of P. quercifolium as a pharmacological option.

Investigating the Effects of Simultaneous Administration of Melatonin and Atorvastatin against High Glucose-Induced Oxidative Stress and Apoptosis in Cultured Chondrocytes.

Osteoarthritis (OA) is a prevalent joint disorder categorized into phenotypic subtypes, including those associated with age, traumatic events, and metabolic syndrome. In the aging population, type 2 diabetes mellitus (T2DM) and osteoarthritis (OA) frequently coexist. This can result in higher rates of disability and a greater financial burden. This study aimed to investigate the protective effects of melatonin and atorvastatin together against oxidative stress and apoptosis induced by high glucose in C28I2 human chondrocytes. After being pretreated for 6 hours with melatonin (10 and 100 μM) and atorvastatin (0.01 and 0.1 μM), C28I2 cells were exposed to a high concentration of D-glucose (75 mM) for 72 hours. The impact of a high D-glucose concentration (75 mM), with or without melatonin and/or atorvastatin, on cell viability, intra-cellular ROS generation, lipid peroxidation level, antioxidant activities, and the expression of proteins, including Bax, Bcl-2, and caspase-3, was analyzed. Melatonin and atorvastatin combination effectively inhibited high glucose-induced cytotoxicity, ROS production, and MDA and mitochondrial membrane potential levels. The combination of melatonin and atorvastatin was more successful in reducing ROS production compared to each of the drugs alone. Melatonin, but not atorvastatin, reversed high glucose-induced alteration in the catalase activity. Furthermore, the combination of melatonin and atorvastatin significantly enhanced the ability of each medication to lower the expression of pro-apoptotic protein Bax. The combination of melatonin and atorvastatin exerted greater protective effects against hyperglycemia-induced toxicity in chondrocytes.

Conditional expression of flagellar motility, curli fimbriae, and biofilms in Shiga toxin- producing Escherichia albertii.

Escherichia albertii is an emerging foodborne pathogen. We previously reported that some avian Shiga toxin-producing E. albertii strains exhibited higher or comparable cytotoxicity in Vero-d2EGFP cells with several enterohemorrhagic E. coli (EHEC) outbreak strains. To better understand the environmental persistence of this pathogen, comparative genomics and phenotypic assays were applied to assess adhesion capability, motility, and biofilm formation in E. albertii. Among the 108 adherence-related genes, those involved in biogenesis of curli fimbriae, hemorrhagic E. coli pilus, type 1 fimbriae, and Sfm fimbriae were conserved in E. albertii. All 20 E. albertii strains carried a complete set of primary flagellar genes that were organized into four gene clusters, while five strains possessed genes related to the secondary flagella, also known as lateral flagella. Compared to EHEC strain EDL933, the eight chemotaxis genes located within the primary flagellar gene clusters were deleted in E. albertii. Additional deletion of motility genes flhABCD and motBC was identified in several E. albertii strains. Swimming motility was detected in three strains when grown in LB medium, however, when grown in 5% TSB or in the pond water-supplemented with 10% pigeon droppings, an additional four strains became motile. Although all E. albertii strains carried curli genes, curli fimbriae were detected only in four, eight, and nine strains following 24, 48, and 120 h incubation, respectively. Type 1 fimbriae were undetectable in any of the strains grown at 37°C or 28°C. Strong biofilms were detected in strains that produced curli fimbriae and in a chicken isolate that was curli fimbriae negative but carried genes encoding adhesive fimbriae K88, a signature of enterotoxigenic E. coli strains causing neonatal diarrhea in piglets. In all phenotypic traits examined, no correlation was revealed between the strains isolated from different sources, or between the strains with and without Shiga toxin genes. The phenotypic variations could not be explained solely by the genetic diversity or the difference in adherence genes repertoire, implying complex regulation in expression of various adhesins. Strains that exhibited a high level of cytotoxicity and were also proficient in biofilm production, may have potential to emerge into high-risk pathogens.

Oral epithelial cells of schoolchildren exposed to air pollution may develop cytotoxic and genotoxic damage

As petrol stations emit pollutants into the atmosphere, their proximity to schools can affect air quality both inside and outside classrooms. School-age children, who spend five to seven hours a day in classrooms and playgrounds during the school year, may be at risk of inhaling potentially harmful gases and particles, which could have a negative impact on their health and academic performance. A biomonitoring study was carried out on 143 children from three schools. Two of the schools were considered to be exposed to volatile organic compounds (VOCs) and were located 50 and 300 metres away from petrol stations. The other school, which was not considered to be exposed, was located 450 metres away. With the exception of MN, the biomarkers of genotoxic damage were generally higher (p>0.05) in the school located 50 metres from a petrol station than in the control group, although the results were less clear in the school located 300 metres away. For all biomarkers (KR, CC, PN and KL), the school 50 metres from the source of emissions had higher levels of cytotoxicity (p <0.05). This is the first study to link exposure to volatile hydrocarbons in petrol to genotoxic damage in children, and it strongly suggests that urban planning laws should be changed to halt the decline in children's health.

Implications of accumulation of clonally expanded and senescent CD4+GNLY+ T cells in immunological non-responders of HIV-1 infection

ABSTRACT Increased CD4+GNLY+ T cells have been confirmed to be inversely associated with CD4+ T cell count in immunological non-responders (INRs), however, the underlying mechanisms are unknown. This study aimed to elucidate the characteristics of CD4+GNLY+ T cells and their relationship with immune restoration. Single-cell RNA sequencing, single-cell TCR sequencing, and flow cytometry were used to analyze the frequency, phenotypes, and function of CD4+GNLY+ T cells. Moreover, Enzyme linked immunosorbent assay was performed to detect plasma cytokines production in patients. CD4+GNLY+ T cells were found to be highly clonally expanded, characterized by higher levels of cytotoxicity, senescence, P24, and HIV-1 DNA than CD4+GNLY− T cells. Additionally, the frequency of CD4+GNLY+ T cells increased after ART, and further increased in INRs, and were positively associated with the antiretroviral therapy duration in INR. Furthermore, increased IL-15 levels in INRs positively correlated with the frequency and senescence of CD4+GNLY+ T cells, suggesting that CD4+GNLY+ T cells may provide new insights for understanding the poor immune reconstitution of INRs. In conclusion, increased, highly clonally expanded, and senescent CD4+GNLY+ T cells may contribute to poor immune reconstitution in HIV-1 infection.

Evaluation of Cytotoxicity of the Dental Materials TheraCal LC, TheraCal PT, ApaCal ART and Biodentine Used in Vital Pulp Therapy: In Vitro Study.

(1) Background: The aim of this study was to compare the cytotoxicity of selected resin-modified materials used in direct contact with the dental pulp (TheraCal LC, TheraCal PT, and ApaCal ART) with calcium silicate cement (Biodentine). (2) Methods: The mouse fibroblast Balb/3T3 cell line and the extracts of tested materials in four concentrations were used for the testing. An MTT assay was performed in three independent experiments with six replicates for each concentration of tested material. The cell viability (%) and cytotoxicity were expressed (cytotoxic effect is considered in cases where the cell viability is lower than 70%). The mean of the cell viability and the standard deviation were expressed for each material at all concentrations. ANOVA and Dunnet's post hoc tests were used for the statistical analysis. All of these tests were performed at the 0.05 significance level. (3) Results: At all concentrations, the cell viability was statistically significantly lower (p ≤ 0.002) for all tested materials compared to Biodentine. ApaCal ART showed a high level of cytotoxicity at all concentrations (cell viability lower than 47.71%, p < 0.0001). The same result was found for TheraCal LC at concentrations of 100%, 50% and 25% and TheraCal PT at concentrations of 100% and 50%. TheraCal LC at a 10% concentration (cell viability 68.18%) and TheraCal PT at a 25% concentration (cell viability 60.63%) indicated potential cytotoxicity. TheraCal PT at a 10% concentration was not found to be cytotoxic (cell viability 79.18%, p = 0.095). (4) Conclusion: The resin-modified calcium silicate and calcium phosphate materials showed higher cytotoxic potential, so they should be used with caution when in direct contact with the dental pulp.

Development of Unique Pyrazoline Analogues for Screening Anticancer and Anti-inflammatory Studies

Cancer is a major threat to human society in the world, which results in a maximum probability of death. In the present scenario, chemotherapy is the main cancer treatment, but still, it has its limitations. Hence, cytotoxic and chemotherapy medicines are the main focus of research for medicinal chemists. So, it is the need of the hour to explore the possibility of effective and safe anticancer drugs. The current research involves the synthesis of pyrazoline derivatives (PYR1-PYR8), which are novel cytotoxic agents developed from recently formulated chalcones (CHL1-CHL8). Title compounds were prepared by subjecting the chalcones with by hydrazine hydrate in ethanolic acetic acid. The purified synthesized compounds were characterized by IR, 1H-NMR, and mass spectroscopic evaluation. Using in-vitro models, cytotoxicity evaluations were conducted on cell lines associated with lung cancer by MTT and SRB methods using doxorubicin as standard, which revealed differing levels of cytotoxic effects among the compounds. The egg albumin denaturation and protein denaturation methods were used to access in-vitro anti-inflammatory activity. Compound PYR4 and PYR6 showed significant anti-inflammatory efficacy in relation to diclofenac sodium as the reference drug. Compound PYR3, PYR4, and PYR6 displayed noteworthy anticancer activity matched to doxorubicin, which is a reference drug. The current research asserts that the newly developed pyrazoline derivatives exhibit high levels of cytotoxicity and anti-inflammatory effects. However, their preclinical and clinical significance needs a thorough evaluation.

Liquid chromatography–mass spectrometry and xCELLigence real time cell analyzer revealed anticancer and antioxidant metabolites in Trianthema portulacastrum L. (Aizoaceae)

BackgroundThe rising incidence of cancer is a major concern globally being a leading cause of early mortality in most countries. This burden is projected to increase to 28.4 million cases worldwide by 2040 and yet, may be worsened by continuous exposure to risk factors due to a sheer shift from consumption of natural nutrients. To reverse this trend, it is imperative to source novel anticancer metabolites from plants that could minimize carcinogenic effects by suppressing the proliferation and survival of cancer cells. PurposeThis study aimed at characterizing and quantifying index anticancer and antioxidant metabolites, in the cultivars of T. portulacastrum. MethodsThe Ultra-High Performance Liquid Chromatography Mass Spectroscopy (UHP-LCMS) was used to quantify and characterize index anticancer and antioxidant metabolites in shoot, root and whole plant extracts of Trianthema portulacastrum (T01,T02,T03,T04,T05,T06). The biological activity of the tested samples was monitored on the xCELLigence Real Time Cell Analyzer to determine the cytotoxicity of the extracts as a function of cell index at a specific time post dose using the concentration range of 0.16–2.5 %. ResultsBased on the responses observed 48 h post exposure, all extracts showed high levels of cytotoxicity as determined by the xCELLigence apart from the root extracts. Rapid decreases in cell index (CI) values observed at higher extract percentages are highly indicative of cell death. These biological activities may be attributed to different anticancer metabolites such as epigallocatechin, glucaric acids, byakangelicin, xanthotoxin, apaensin, acetoxy-6-gingerol among other compounds of significant therapeutic benefits that were quantified with UHP-LCMS. ConclusionThese findings suggest that T. portulacastrum contains diverse anticancer metabolites which could be leveraged to develop plant-based anticancer drugs or novel chemicals with extended therapeutic utility.

Abstract 5245: Anti-CSPG4 CAR-Macrophages synergize with anti-CD47 in melanoma cytotoxicity

Abstract While CAR T-cells have been a success in treating liquid tumors, these successes have not been replicated in solid tumors. There are several reasons for these challenges, including physical matrix barriers and increased tumor antigen heterogeneity in solid tumors. Macrophages are frequently found in melanoma tumors, even in those that have low T-cell infiltrate, suggesting macrophages are well equipped to penetrate the physical barriers surrounding solid tumors. Macrophages are also antigen-presenting cells, thus, if macrophages phagocytose the tumor, they will likely present additional antigens to T-cells, potentially enhancing the adaptive immune response in cancer treatment. Thus, we hypothesized that macrophages expressing chimeric antigen receptors (CAR-Macrophages or CAR-Ms) are able to access solid tumors, phagocytose cancer cells, and subsequently re-educate the tumor immune environment by directly polarizing tumor-associated macrophages and by presenting novel antigens to recruit and educate adaptive immune cells. To test these hypotheses, we generated CAR-Ms with primary human macrophages using an scFV specific to chondroitin sulfate proteoglycan 4 (CSPG4), a highly expressed antigen enriched and specific to melanoma tumors, and an intracellular activation domain to promote phagocytosis. We found that anti-CSPG4 CAR-Ms phagocytosed human melanoma cells at high efficiency, however, this phagocytosis did not result in high levels of melanoma cell cytotoxicity. To improve CAR-M-mediated melanoma cell death engulfment, we blocked the anti-CD47/SIRPα (“don’t eat me”) signaling axis with an anti-CD47 blocking antibody, which resulted in additive effects for phagocytosis, and a robust effect on the melanoma cell killing. Preliminary in vivo xenograft experiments suggest that anti-CSPG4 CAR-Ms alone delay melanoma growth. We are now testing whether combining anti-CD47 and CSPG4 CAR-Ms therapies in vivo can 1) further reduce primary tumor growth and 2) prevent recurrence following surgical resection by treating remnants of the tumor. Our work shows that CSPG4 CAR-M-mediated killing of CSPG4-positive cancer cells is significantly enhanced when in combination with anti-CD47 antibody treatment. Citation Format: Daniel Greiner, Qian Xue, Trinity Waddell, Minna Roh-Johnson. Anti-CSPG4 CAR-Macrophages synergize with anti-CD47 in melanoma cytotoxicity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5245.

Cytotoxicity of luteolin, a flavonoid compound isolated from &lt;i&gt;Anthemis palestina&lt;/i&gt;

Purpose: To determine the active principle responsible for the cytotoxic effect of Anthemis palestina (Reut. ex Kotschy) Reut. ex Boiss. (Asteraceae).&#x0D; Methods: A bioassay-guided fractionation was used to isolate the active principle, luteolin, which structure was elucidated using 1H and 13C NMR. The cytotoxic effects of luteolin and doxorubicin (positive control) in the breast cancer cell lines MDA-MB-231 and MCF-7, and in normal fibroblasts, were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay.&#x0D; Results: Luteolin was isolated from the ethyl acetate extract of the aerial parts of Anthemis palestina. With an IC50 value of 14.91 ± 5.77 µM for MDA-MB-231 cells, luteolin was less active than doxorubicin. However, with respect to MCF-7 cells, there was no significant difference in the cytotoxicity values of luteolin and doxorubicin, with IC50 value of 29.28 ± 11.85 µM for luteolin. However, with an IC50 value of 51.39 ± 18.51 µM against fibroblasts, luteolin was significantly safer than doxorubicin.&#x0D; Conclusion: Luteolin might be responsible for the cytotoxicity of Anthemis palestina. The high level of luteolin cytotoxicity indicates the potential benefits of Anthemis palestina, not only in terms of its taste, but also for its likely positive therapeutic impact on cancer, especially breast cancer.

Redox-responsive biodegradable dendronized polymers: A side-chain modulation based fabrication of drug delivery vehicles

Among various nanomedicine platforms, stimuli-responsive biodegradable polymeric micelles offer a viable approach to address challenges in cancer therapy. Herein, we report the fabrication of redox-responsive micellar aggregates based on an amphiphilic dendron-polymer conjugate. In particular, acid-degradable hydrophobic polyester dendrons are attached as side chain moieties through a disulfide linkage on a hydrophilic copolymer. Polymers containing three generations of dendrons are synthesized using the thiol-disulfide exchange reaction and utilized to obtain micellar aggregates. The stability of the obtained aggregates, drug loading, and release characteristics in neutral, acidic, and redox environments were investigated. It was established that micelles are efficiently internalized by cells, and the highest level of cytotoxicity was observed for MDA-MB-231 breast cancer carcinoma cells under a reducing environment.

Apparent Cytotoxicity and Intrinsic Cytotoxicity of Lipid Nanomaterials Contained in a COVID-19 mRNA Vaccine

The medicinal preparation called Comirnaty by Pfizer-BioNTech is an aqueous dispersion of lipid nanomaterials, intended to constitute, after thawing and dilution, the finished product for intramuscular injection. In the present study, we examine some evident chemical-physical criticalities of the preparation, particularly regarding the apparent and the intrinsic pKa (acid dissociation constant) of its main excipient, the ionizable cationic lipid ALC-0315. The very high value of its intrinsic pKa causes, after internalization and endosomal escape of LNPs, a sudden increase of its cationic charge concentration and consequently the formation of pro-inflammatory cytokines and ROS (reactive oxygen species), that can disrupt the mitochondrial membrane and release its content, cause RNA mistranslation, polymerization of proteins and DNA, DNA mutations, destruction of the nuclear membrane and consequent release of its content. Additionally, the apparently low pKa value (6.09) of ALC-0315 associated with other lipids in the LNP, is not suitable for intramuscular application. Its value is too low to enable a proper transfection of host cells, despite what is stated by EMA (European Medicines Agency) in its Assessment report dated 19 February 2021, in flagrant contradiction with the same bibliographic source therein cited. Furthermore, the exceptional penetrability, mobility, chemical reactivity and systemic accumulation of uncontrollable cationic lipid nanoparticles, with high cytotoxicity levels, shed in unpredictable biological locations, even far from the site of inoculation, are all factors that can lead to an unprecedented medical disaster. Meanwhile, further immediate studies and verifications are recommended, taking into consideration, in accordance with the precautionary principle, the immediate suspension of vaccinations with the COVID-19 mRNA- LNP-based vaccines.

Estrogenic activity and acute toxicity assessments of sediments from a chronically polluted estuarine area in southeastern Brazil

AbstractCompounds displaying estrogenic potential can lead to serious negative aquatic ecosystem impacts, and exposure to mixtures of endocrine disruptors present in environmental matrices with very complex characteristics, including sediments, can cause serious risks to biota, animals, and humans. Within this perspective, the aim of the present study was to assess estrogenic activity and toxicity in sediments sampled from Guanabara Bay, the most important, although chronically polluted, estuary in southeastern Brazil. To this end, estrogenic activity determinations were performed by the yeast estrogen screen (YES) assay, and acute toxicity assays were carried out employing Vibrio fischeri. Estrogenic activity was quantified up for 8.7 ng g−1 in E2‐EQ, although high levels of cytotoxicity (up to 95%) were observed and might have hindered the determination of the real estrogenic potential in most samples. Acute toxicity to V. fischeri ranged from 0 to 45.21%. These results point to potential deleterious effects caused by micropollutants and underline the urgency of continuous monitoring of the degradation degree of the Guanabara Bay estuary.

Pathogenicity assessment of Shiga toxin-producing Escherichia coli strains isolated from wild birds in a major agricultural region in California.

Shiga toxin-producing Escherichia coli (STEC) consists of diverse strains differing in genetic make-up and virulence potential. To better understand the pathogenicity potential of STEC carried by the wildlife, three STEC and one E. coli strains isolated from wild birds near a major agricultural region in California were selected for comparative pathogenomic analyses. Three American crow (Corvus brachyrhynchos) strains, RM9088, RM9513, and RM10410, belonging to phylogroup A with serotypes O109:H48, O9:H30, and O113:H4, respectively, and a red-winged blackbird (Agelaius phoeniceus) strain RM14516 in phylogroup D with serotype O17:H18, were examined. Shiga toxin genes were identified in RM9088 (stx1a), RM10410 (stx1a + stx2d), and RM14516 (stx2a). Unlike STEC O157:H7 strain EDL933, none of the avian STEC strains harbored the pathogenicity islands OI-122, OI-57, and the locus of enterocyte effacement, therefore the type III secretion system biogenesis genes and related effector genes were absent in the three avian STEC genomes. Interestingly, all avian STEC strains exhibited greater (RM9088 and RM14516) or comparable (RM10410) cytotoxicity levels compared with EDL933. Comparative pathogenomic analyses revealed that RM9088 harbored numerous genes encoding toxins, toxins delivery systems, and adherence factors, including heat-labile enterotoxin, serine protease autotransporter toxin Pic, type VI secretion systems, protein adhesin Paa, fimbrial adhesin K88, and colonization factor antigen I. RM9088 also harbored a 36-Kb high pathogenicity island, which is related to iron acquisition and pathogenicity in Yersinia spp. Strain RM14516 carried an acid fitness island like the one in EDL933, containing a nine gene cluster involved in iron acquisition. Genes encoding extracellular serine protease EspP, subtilase cytotoxin, F1C fimbriae, and inverse autotransporter adhesin IatC were only detected in RM14516, and genes encoding serine protease autotransporter EspI and P fimbriae were only identified in RM10410. Although all curli genes were present in avian STEC strains, production of curli fimbriae was only detected for RM9088 and RM14516. Consistently, strong, moderate, and little biofilms were observed for RM9088, RM14516, and RM10410, respectively. Our study revealed novel combinations of virulence factors in two avian strains, which exhibited high level of cytotoxicity and strong biofilm formation. Comparative pathogenomics is powerful in assessing pathogenicity and health risk of STEC strains.

Vibrio metschnikovii as an emergent pathogen: analyses of phylogeny and O-antigen and identification of possible virulence characteristics

ABSTRACT Vibrio metschnikovii is an emergent pathogen that causes human infections which may be fatal. However, the phylogenetic characteristics and pathogenicity determinants of V. metschnikovii are poorly understood. Here, the whole-genome features of 103 V. metschnikovii strains isolated from different sources are described. On phylogenetic analysis V. metschnikovii populations could be divided into two major lineages, defined as lineage 1 (L1) and 2 (L2), of which L1 was more likely to be associated with human activity. Meanwhile, we defined 29 V. metschnikovii O-genotypes (VMOg, named VMOg1–VMOg29) by analysis of the O-antigen biosynthesis gene clusters (O-AGCs). Most VMOgs (VMOg1 to VMOg28) were assembled by the Wzx/Wzy pathway, while only VMOg29 used the ABC transporter pathway. Based on the sequence variation of the wzx and wzt genes, an in silico O-genotyping system for V. metschnikovii was developed. Furthermore, nineteen virulence-associated factors involving 161 genes were identified within the V. metschnikovii genomes, including genes encoding motility, adherence, toxins, and secretion systems. In particular, V. metschnikovii was found to promote a high level of cytotoxicity through the synergistic action of the lateral flagella and T6SS. The lateral flagellar-associated flhA gene played an important role in the adhesion and colonization of V. metschnikovii during the early stages of infection. Overall, this study provides an enhanced understanding of the genomic evolution, O-AGCs diversity, and potential pathogenic features of V. metschnikovii.

Coccoloba uvifera Leaves: Polyphenolic Profile, Cytotoxicity, and Antioxidant Evaluation.

This study aimed to investigate the chemical composition of Coccoloba uvifera leaves and evaluate the antioxidant and antitumor effects of the total extract and its major metabolites. Four assays were used to determine the antioxidant activity, including radical scavenging abilities of 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), radical cation, and ferric-reducing power. Additionally, vincristine was used as a reference medication to examine the anticancer activity on Ehrlich aesthete carcinoma cells (EACC). Nine compounds were isolated from C. uvifera leaves aqueous methanol extract. Their structures were identified as gallic acid (1), methyl gallate (2), protocatechuic acid methyl ester (3), protocatechuic acid (4), quercetin 3-O-β-d-glucopyranoside (isoquercitrin, 5), kaempferol 3-O-β-D-neohespridoside (6), myricitrin 4″-O-gallate (7), myricetin 3-O-β-d-glucopyranoside (8), and myricetin 3-O-arabinopyranoside (9). The majority possess noticeable antioxidant and antitumor properties. However, compounds 1, 5, 4, 2, and 7 displayed a strong antioxidant potential in terms of DPPH radical scavenging activity, with values of 85.72 ± 0.30, 82.16 ± 0.20, 81.34 ± 0.20, 79.62 ± 0.29, and 79.34 ± 0.20%, respectively. Compounds 4, 1, 5, 7, and 2 revealed high reducing power activity, with respective values of 1.348 ± 0.043, 1.303 ± 0.011, 1.154 ± 0.020, 1.058 ± 0.032, and 1.056 ± 0.019. Compounds 4 and 1 showed the highest ABTS radical scavenging capabilities (91.90 ± 0.24 and 91.83 ± 0.74%) and ferric-reducing power ability (1979 ± 14.53 and 1965 ± 26.86 μmol Trolox/100 g, respectively). Compound 4 has the highest level of cytotoxicity, resulting in 78.710.21% dead cells.

RESEARCH ON VARIOUS MODELS OF THE BIOLOGICAL EFFECTS OF COMPONENTS OF A COMPLEX EFFECT (PHOTOIRRADIATION; EXOSOMES OF MESENCHYMAL STEM CELLS AND NANOPARTICLES) FOR THE CORRECTION OF THE INFLAMMATORY PROCESS

RESEARCH ON VARIOUS MODELS OF THE BIOLOGICAL EFFECTS OF COMPONENTS OF A COMPLEX EFFECT (PHOTOIRRADIATION; EXOSOMES OF MESENCHYMAL STEM CELLS AND NANOPARTICLES) FOR THE CORRECTION OF THE INFLAMMATORY PROCESS

3D Aerosol Jet® printing for microstructuring: Advantages and limitations

Aerosol Jet&amp;reg; printing (AJ&amp;reg;P) is a direct writing printing technology that deposits functional aerosolized solutions on free-form substrates. Its potential has been widely adopted for two-dimensional (2D) microscale constructs in printed electronics (PE), and it is rapidly growing toward surface structuring and biological interfaces. However, limited research has been devoted to its exploitation as a three-dimensional (3D) printing technique. In this study, we investigated AJ&amp;reg;P capabilities for 3D microstructuring of three inks, as well as their advantages and limitations by employing three proposed 3D AJ&amp;reg;P strategies (continuous jet deposition, layer-by-layer, and point-wise). In particular, 3D microstructures of increasing complexity based on silver nanoparticle (AgNPs)-, poly(3,4-ethylenedioxythiophene)polystyrene sulfonate (PEDOT:PSS)-, and collagen-based inks were investigated at various aspect ratios and resolutions. Biocompatibility assays were also performed to evaluate inks cytotoxicity effects on selected cellular lineages, including neuronal and osteoblast cell lines. Results show the possibility to print not only arrays of micropillars of different aspect ratios (AgNPs-ARs ~ 20, PEDOT:PSS-ARs ~ 4.5, collagen-ARs ~ 2.5), but also dense and complex (yet low reproducible) leaf- or flake-like structures (especially with the AgNPs-based ink), and lattice units (collagen-based ink). Specifically, this study demonstrates that the fabrication of 3D AJ&amp;reg;-printed microstructures is possible only with a specific set of printing parameters, and firmly depends on the ink (co-)solvents fast-drying phenomena during the printing process. Furthermore, the data concerning inks biocompatibility revealed high cytotoxicity levels for the AgNPs-based ink, while low ones for the PEDOT:PSS and the collagen-based inks. In conclusion, the paper provides general guidelines with respect to ink development and print strategies for 3D AJ&amp;reg;P microstructuring, opening its adoption in a vast range of applications in life science (tissue engineering, bioelectronic interfaces), electronics, and micromanufacturing.