Dose-dependent Negative Effect Research Articles

Chaos in the Colon: Unlocking the Puzzle of DRA (SLC26A3) Downregulation with IL-1α and p38 MAPK Amidst Brachyspira Turmoil

This study examines the impact of Brachyspira hyodysenteriae and Brachyspira hampsonii infection on chloride (36Cl−) transport within the porcine colon. Utilizing 3H-mannitol and 36Cl−, we evaluated the bidirectional flux across colonic tissues from both healthy and infected pigs. We observed no change in 3H-mannitol flux, indicating unaffected paracellular movement. However, we observed a significant decrease in mucosal-serosal 36Cl− flux (Jm-s) in the apical segment of the spiral colon of infected pigs, suggesting a compromised chloride absorption due to the downregulation of DRA (SLC26A3), confirmed by reduced mRNA and protein levels. To dissect the molecular dynamics in vitro, we exposed polarized Caco-2 cells to B. hampsonii lysate. This model recapitulated the in vivo responses, including the downregulation of DRA and the concomitant IL-1α upregulation. This in vitro model demonstrated that B. hampsonii lysate upregulates IL-1α expression through p38 MAPK phosphorylation. More importantly, in vitro studies with B. hampsonii lysate, recombinant IL-1α, SB 203580 (p38 MAPK inhibitor), and blocking IL-1α signalling with IL-1 receptor antagonist (IL-1RA) revealed that IL-1α has a dose-dependent negative effect on DRA expression and a positive effect on IL-1α expression. Furthermore, inhibiting IL-1α expression with SB 203580 and blocking IL-1α signalling with IL-1RA not only prevented this downregulation of DRA but also promoted its upregulation, highlighting the regulatory role of IL-1α in chloride absorption. In summary, this study presents an in-depth understanding by which Brachyspira infections can impede chloride absorption in the colon and offers potential intervention targets for conditions involving impaired DRA-mediated Cl− transport. This research was supported by Alberta Livestock Meat Association (ALMA 2013R054R) and Natural Sciences and Engineering Research Council of Canada Discovery Grant 02743-2021 (to M. E. Loewen). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Abstract 4494: Cryo-EM structure-based small molecule inhibitor drugs targeting CSPG4/NG2 in glioblastoma

Abstract Background: Glioblastoma (GBM) is the most malignant primary brain tumor with a median survival of 15 months despite aggressive multimodal treatment. There is an urgent need for novel drug discovery for GBM. CSPG4/NG2 transmembrane proteoglycan is a validated target, upregulated in 50% of GBM patient tumours, drives malignant progression and is independently prognostic for poor survival. We have recently identified a cancer specific 13 bp frameshift deletion in the CSPG4/NG2 gene (CSPG4/NG2del13), which leads to reduced protein expression and slowed cell growth in vitro and tumor take in vivo. The 3D structure of CSPG4/NG2 has not yet been solved, and unsuited for structure prediction by AlphaFold2 due to its size and PTMs. The structure of CSPG4/NG2 domain 1 (residues 411-547), containing the site of the 13 bp deletion, has been solved using cryo-EM and can be useful for new drug design. We hypothesize that a small-molecule inhibitor that binds to this 13 bp region of the CSPG4/NG2 proteoglycan, might induce the same phenotype as the 13 bp deletion. Methods: Using the published structure of domain 1, we performed in silico analysis to predict binding sites and docked 1280 compounds from the Prestwick Chemical library’s database of FDA-approved drugs to these sites. The high ranked hits were further tested in vitro in GBM cells. Clonogenic survival, cell proliferation and scratch-wound assays were performed in patient derived P3, A172 and in CSPG4/NG2del13 heterozygous (HZ) GBM cells, that served as controls. Results: Three binding sites were found in the close proximity to the 13 bp deletion region within the N-terminal domain 1 of CSPG4/NG2. Docking analysis revealed multiple drug candidates bound to the predicted binding site, three of which were further analyzed. Dopamine is found to closely interact with CSPG4/NG2 domain 1, near the 13 bp deletion site, forming hydrogen bonds with Glu413 and Glu521. Pyrazinamide forms two hydrogen bonds with Glu521. 5-Azacytidine fits well into active site 1, establishing hydrogen bonds with key residues Gly475, Glu482, Val472 and Thr473. The in vitro functional assays showed that the top hits have a dose dependent negative effect on colony formation and cell proliferation in P3 and A172 GBM cells (P < 0.0001). The treatment with the same drug IC50 doses led to a growth rescue in the CSPG4/NG2del13 HZ cells compared to the WT cells (P < 0.001). 5-Azacytidine showed a significant inhibitory effect (P < 0.0001) on cell migration in P3, A172 GBM cells and also in HZ cells, (P < 0.001). Conclusion: The residues spanning the site of 13 bp deletion have chemical motifs that are salient for docking small molecule inhibitors that disrupt CSPG4/NG2 function. N-terminus domain 1 and full-length CSPG4/NG2 proteins for Cryo-EM 3D structure determination are being used to interrogate biochemical kinetics and identify new target regions. Citation Format: Lasse Neset, Mia Kristin Nilsen, Victoria Smith Arnesen, Kazi Asraful Alam, Martha Chekenya, Mohummad Aminur Rahman. Cryo-EM structure-based small molecule inhibitor drugs targeting CSPG4/NG2 in glioblastoma [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 4494.

Impact of Anti-Mycotic Drugs on the Osteogenic Response of Bone Marrow Mesenchymal Stem Cells In Vitro.

The treatment of fungal bone infections and infected non-unions is a huge challenge in modern trauma and orthopedics, which normally contain the local and systemic administration of anti-fungal drugs. Although frequently used, little is known about the impact of systemic and locally administered fungicides on the osteogenic regenerative capabilities of infected bone tissue, especially upon the osteogenesis of human bone marrow mesenchymal stem cells (BM-hMSCs). This study evaluates the effects of the three most common fungicides for the systemic treatment of bone infections, Voriconazole (VOR), liposomal Amphotericin B (LAMB), and Fluconazole (FLU), as well as the effects of VOR and LAMB-loaded Polymethylmethacrylate (PMMA) cement chips in different concentrations upon the osteogenic response of BM-hMSCs in vitro. Within this study, we compared the ability of BM-hMSC to differentiate into osteoblast-like cells and synthesize hydroxyapatite as assessed by radioactive 99mTechnetium-Hydroxydiphosphonate (99mTc-HDP) labeling, cell proliferation, and analyses of supernatants upon various osteogenic parameters. Our results revealed that VOR added to the cell culture medium affects the osteogenic potential of BM-hMSC negatively, while there were no detectable effects of LAMB and FLU. Moreover, we showed dose-dependent negative effects of high- and extended-dose fungicide-loaded PMMA cement due to cytotoxicity, with a higher cytotoxic potential of VOR than LAMB, while low-dose fungicide-loaded PMMA had no significant effect on the osteogenic potential of BM-hMSC in vitro.

Physiological and histopathological effects of polystyrene nanoparticles on the filter-feeding fish Hypophthalmichthys molitrix

Excessive use of plastics in daily life is causing plastic pollution in aquatic environment and threatening the aquatic life. Therefore, research on the plastic pollution in aquatic environment is crucial to understand its impact and develop effective solution for safeguarding aquatic life and ecosystem. The current study investigated the effects of water borne polystyrene nanoparticles (PS-NPs) on hemato-immunological indices, serum metabolic enzymes, gills, and liver antioxidant parameters, plasma cortisol level and histopathological changes in liver and gill tissues of the widely distributed fish Hypophthalmichthys molitrix. The fingerlings of H. molitrix were exposed to different concentrations (T1–0.5, T2–1.0, and T3–2.0 mg/L) of PS-NPs respectively for 15 days consecutively. Our results indicated the dose dependent negative effects of PS-NPs on the physiology and histopathology of H. molitrix. Immuno-hematological indices showed significant increase in WBCs count, phagocytic activity, and lysozyme activity, while decreased RBC count, Hct%, Hb level, total proteins, IgM, and respiratory burst activity were observed. The levels of antioxidant enzymes like SOD, CAT and POD showed the decreasing trends while metabolic enzymes (AST, ALT, ALP and LDH), LPO, ROS activities and relative expressions of SOD1, CAT, HIF1-α and HSP-70 genes increased with increased concentrations of PS-NPs. Moreover, blood glucose and cortisol levels also showed significant increasing trends with dose dependent manner. Histopathological examination indicated moderate to severe changes in the gills and liver tissues of the group treated with 2.0 mg/L of PS-NPs. Overall, the results showed the deleterious effects of PS-NPs on physiology, immunity, metabolism, and gene expressions of H. molitrix. It is concluded that particulate plastic pollution has deleterious effects on filter feeding fish, which might affect human health through food chain and particulate chemical toxicity.

Post Reclamation Evaluation of Residual Hydrocarbons in Crude Oil Contaminated Soil Using Gas Chromatographic Techniques and Plant Growth Indices

The present study was undertaken to evaluate the post-reclamation of crude oil-contaminated soil using gas chromatographic technique and plant growth indices. Enrichment techniques, turbidometric test, plasmid curing test, classical identification method, gas chromatographic flame ionization detection technique and plant growth indices were carried out using standard procedures. The results indicated that 22 of the isolates were observed to have high pollutant degrading potentials (A600nm > 0.3) due to their crude oil utilization ability. The results also indicated that isolates which were able to degrade crude oil belonged to genera Bacillus, Pseudomanas sp., Ochrobacterium sp. and Enterobacter sp. Moreso, the remediation percentages recorded were 98 %, 80 %, 21 % and 98 %, 78 % and 22 % for the respective crude oil pollution (3 %, 5 % and 10 %) for soil inoculated plasmid borne bacteria whereas soil inoculated with plasmid cured bacterial cultures had 65 %, 52 %, 11 % and 65 %, 50 % and 20 % degradation of the same concentration of the total petroleum hydrocarbon after 60 days for both Phaseolus vulgaris and Glycine max plant seeds, respectively. The remediation percentages in the uninoculated controls include 3 %, 5 %, 10 % and 12 %, 9 % and 5 % across the pollutions for both plant seeds. A significant (P < 0.05) increase in the growth parameters of the leguminous plants like percentage germination, mean plant shoot length, mean plant root length, plant fresh weight and number of root nodules were seen more in the soil microcosms inoculated with plasmid-borne bacteria than microcosm inoculated with culture of plasmid cured bacteria across all crude oil dilutions. Crude oil had a dose-dependent negative effect on the mean bacterial counts of each of the polluted soil containing the two different plants. Thus, the study clearly suggests that the selected hydrocarbon bacterial degraders could be effectively exploited in the remediation of crude oil-polluted sites.

Transcriptomic hallmarks of in vitro TiO2 nanotubes toxicity in Chlamydomonas reinhardtii

Recently, more accessible transcriptomic approaches have provided a new and deeper understanding of environmental toxicity. The present study focuses on the transcriptomic profiles of green microalgae Chlamydomonas reinhardtii exposed to new industrially promising material, TiO2 nanotubes (NTs), as an example of a widely used one-dimensional nanomaterial. The first algal in vitro assay included 2.5 and 7.5 mg/L TiO2 NTs, resulting in a dose-dependent negative effect on biological endpoints. At a working concentration of 7.5 mg/L, RNA-sequencing showed a mainly negative effect on the cells. In summary, the results indicated metabolic disruption, such as ATP loss, damage to mitochondria and chloroplasts, loss of solutes due to permeated membranes, and cell wall damage. Moreover, apoptosis-induced transcripts were detected. Interestingly, reactivation of transposons was observed. In signalling and transcription pathways, including chromatin remodelling and locking, the annotated genes were downregulated.

Selective Voltammetric Sensor for the Simultaneous Quantification of Tartrazine and Brilliant Blue FCF.

Tartrazine and brilliant blue FCF are synthetic dyes used in the food, cosmetic and pharmaceutical industries. The individual and/or simultaneous control of their concentrations is required due to dose-dependent negative health effects. Therefore, the paper presents experimental results related to the development of a sensing platform for the electrochemical detection of tartrazine and brilliant blue FCF based on a glassy carbon electrode (GCE) modified with MnO2 nanorods, using anodic differential pulse voltammetry. Homogeneous and stable suspensions of MnO2 nanorods have been obtained involving cetylpyridinium bromide solution as a cationic surfactant. The MnO2 nanorods-modified electrode showed a 7.9-fold increase in the electroactive surface area and a 72-fold decrease in the electron transfer resistance. The developed sensor allowed the simultaneous quantification of dyes for two linear domains: in the ranges of 0.10-2.5 and 2.5-15 μM for tartrazine and 0.25-2.5 and 2.5-15 μM for brilliant blue FCF with detection limits of 43 and 41 nM, respectively. High selectivity of the sensor response in the presence of typical interference agents (inorganic ions, saccharides, ascorbic and sorbic acids), other food dyes (riboflavin, indigo carmine, and sunset yellow), and vanillin has been achieved. The sensor has been tested by analyzing soft and isotonic sports drinks and the determined concentrations were close to those obtained involving the chromatography technique.

Bioplastic (PHBV) addition to soil alters microbial community structure and negatively affects plant-microbial metabolic functioning in maize

Microplastic contamination poses a significant threat to agroecosystem functioning, provoking a move away from the use of conventional oil-based plastics in agriculture, to biodegradable alternatives that may be degraded over a shorter timescale. The impact of these bioplastics on plant and soil health, however, has received relatively little attention. Here, we investigated the effect of soil loading (0.01%, 0.1%, 1% and 10%) of biobased microplastic poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) on soil and plant ( Zea mays L.) health and function. We showed that PHBV caused a dose-dependent reduction in plant growth and foliar nitrogen (N) content while untargeted metabolite analysis revealed significant shifts in foliar metabolic function. These results were also reflected in soil, where PHBV led to reduced plant availability of both ammonium and nitrate. Soil 14 C-isotope tracing and 16 S metabarcoding revealed that PHBV supressed microbial activity, reduced bacterial diversity and shifted microbial community structure, inducing a major shift in soil metabolic pathways, and thus functioning. Overall, our data suggests that the bioplastic PHBV is not environmentally benign and that contamination levels as low as 0.01% (0.01 mg kg -1 ) can induce significant short-term changes in both plant and soil microbial functioning, with potential implications for long term agroecosystem health. • Effect of biopolymer PHBV microplastic on soil and plant health was investigated • PHBV addition caused a dose-dependent negative effect on soil and plant health • PHBV addition altered foliar metabolism and reduced plant growth and foliar N • PHBV reduced soil microbial activity and changed the bacterial community structure • Bioplastics may not be environmentally benign

Consumption of sugar-sweetened beverages and fast foods deteriorates adolescents' mental health.

Sugar-sweetened beverage (SSB) and fast-food consumption is significantly associated with adolescents' poor mental health. Furthermore, sugar-sweetened beverage and fast-food consumption might form clustered diet patterns with significant positive associations in adolescent high school students. Thus, the combined consumption of SSBs and fast foods may have more negative effects on mental health with synergetic effects than the sum of their independent consumption. This study aimed to identify the effects of combining the consumption of sugar-sweetened beverages and fast foods on mental health, including stress, depressive symptoms, and suicidal ideation among Korean high school students. Secondary data from 24,006 high school students were analyzed from the 17th Korea Youth Risk Behavior Web-based Survey, 2021. For statistical analysis, complex sampling analysis using the SPSS Statistics 26.0 software was applied for descriptive statistics and logistic regression analysis. In Korean adolescents, combining more than medium consumption of sugar-sweetened beverages and fast foods was associated with more stress, depressive symptoms, and suicidal ideation than their independent consumption. In addition, combining high consumption of sugar-sweetened beverages and low to high consumption of fast foods might have dose-dependent negative effects on stress, depressive symptoms, and suicidal ideation in Korean adolescents. Based on the results of this study, healthcare providers in schools and communities might develop various interventions including school/community-based feeding programs and policies targeting the restriction of SSB and fast-food consumption to improve adolescents' mental health.

In vitro testing and efficacy of poly-lactic acid coating incorporating antibiotic loaded coralline bioceramic on Ti6Al4V implant against Staphylococcus aureus.

Biofilm formation on an implant surface is most commonly caused by the human pathogenic bacteria Staphylococcus aureus, which can lead to implant related infections and failure. It is a major problem for both implantable orthopedic and maxillofacial devices. The current antibiotic treatments are typically delivered orally or in an injectable form. They are not highly effective in preventing or removing biofilms, and they increase the risk of antibiotic resistance of bacteria and have a dose-dependent negative biological effect on human cells. Our aim was to improve current treatments via a localized and controlled antibiotic delivery-based implant coating system to deliver the antibiotic, gentamicin (Gm). The coating contains coral skeleton derived hydroxyapatite powders (HAp) that act as antibiotic carrier particles and have a biodegradable poly-lactic acid (PLA) thin film matrix. The system is designed to prevent implant related infections while avoiding the deleterious effects of high concentration antibiotics in implants on local cells including primary human adipose derived stem cells (ADSCs). Testing undertaken in this study measured the rate of S. aureus biofilm formation and determined the growth rate and proliferation of ADSCs. After 24h, S. aureus biofilm formation and the percentage of live cells found on the surfaces of all 5%-30% (w/w) PLA-Gm-(HAp-Gm) coated Ti6Al4V implants was lower than the control samples. Furthermore, Ti6Al4V implants coated with up to 10% (w/w) PLA-Gm-(HAp-Gm) did not have noticeable Gm related adverse effect on ADSCs, as assessed by morphological and surface attachment analyses. These results support the use and application of the antibacterial PLA-Gm-(HAp-Gm) thin film coating design for implants, as an antibiotic release control mechanism to prevent implant-related infections.

Combined proteomic and gene expression analysis to investigate reduced performance in rainbow trout (Oncorhynchus mykiss) caused by environmentally relevant microplastic exposure

The pollution of the environment with microplastics (MPs) is affecting aquatic organisms worldwide, and yet intensive research, has thus far failed to deliver an adequate understanding of the detrimental effects of MP ingestion by fish. Investigations using established health and performance parameters are often insufficient to determine MP toxicity, especially when considering MPs in environmentally relevant concentrations. In the present study, label-free quantitative (LFQ) proteomics of liver tissue was combined with gene expression analysis in order to investigate the long-term effects of MP exposure on rainbow trout (Oncorhynchus mykiss). With the help of a specially designed diet, two groups of fish were exposed for 120 days to environmentally relevant concentrations of MPs (on average 13 particles per fish, every 2 days) and to slightly increased levels representing those expected in the near future (on average 73 MP particles per fish, every 2 days). Both groups were compared to a control. The results provide evidence that long-term exposure to MPs has a dose-dependent negative effect on the performance of rainbow trout. No differences in blood glucose level, hematocrit level or lipid peroxidation were observed between treatments. The proteomic analysis revealed 6071 unique proteins, but no significant change in hepatic protein concentrations compared to their matching controls, although certain proteins appear to have been up- or down-regulated multifold and should be considered in continuing experiments. When comparing highly regulated proteins with the levels of their respective mRNA transcripts, a good correlation was observed just for “differentially regulated trout protein 1”, encoded by drtp1. This may therefore be a suitable biomarker for future studies with trout. Several hypotheses were put forward to explain the observed differences in growth: nutrient dilution, caused by increased amounts of non-digestible material in the diet, and growth effects due to differences in diet quality could be excluded. Physical interference of MPs with the gastrointestinal tract are also unlikely, as fish are regularly exposed to particulate matter in natural environments and previous studies did not find evidence of such interferences. Instead, indirect detrimental effects of MPs, either due to their hydrophobic surface properties or the presence of certain additives, could cause allergic reactions, microbiota dysbiosis or general stress responses. Although no clear cause for the reduced growth was identified, the current study demonstrates the potential utility of omics approaches when dealing with such a complex question. Future studies should extend analyses to the gastrointestinal tract and associated tissues. It should be ensured that the MP exposure is realistic and that the duration of the experiments covers several months. Direct evidence of a significant negative influence of long-term exposure to realistic and near-future MP concentrations on fish highlight the importance of measures to prevent a further increase of MPs in the environment.

Effects of Monobenzyl ether of hydroquinone on 3T3 mouse fibroblast viability and ultrastructure

ABSTRACT Monobenzyl ether of hydroquinone (MBEH) is a topical depigmentation agent used by vitiligo patients to even the skin tone. We aimed to investigate the effects of MBEH on 3T3 mouse fibroblasts. Fibroblasts were treated with 250 µM, 500 µM, and 750 µM MBEH and vehicle (EtOH:DMSO) for 24 hours. Cell numbers of 250 µM, 500 µM, and 750 µM MBEH treated and vehicle groups decreased significantly compared to control group. TUNEL positive cell rate increased with MBEH concentration. In electron microscopic examination, control and vehicle groups showed active cells features, while mitochondrial swelling and cristae loss were seen in 250 µM MBEH-treated group. In cytoplasm of 500 µM MBEH-treated group, there were many multivesicular bodies and autophagic vacuoles. As an indication of apoptosis, cell membrane blebs and reduction in cell size were observed. In 750 μM MBEH-treated group, cells were completely degenerated. Our findings show that MBEH, which is used as a depigmentation agent to lighten the skin by destroying melanocytes, may also have dose-dependent negative effects on the viability of 3T3 mouse fibroblasts, and these may be mediated through autophagic and apoptotic cell death mechanisms.

Glyphosate-Eating Fungi: Study on Fungal Saprotrophic Strains' Ability to Tolerate and Utilise Glyphosate as a Nutritional Source and on the Ability of Purpureocillium lilacinum to Degrade It.

Glyphosate is the most commonly used herbicide worldwide. Its improper use during recent decades has resulted in glyphosate contamination of soils and waters. Fungal bioremediation is an environmentally friendly, cost effective, and feasible solution to glyphosate contamination in soils. In this study, several saprotrophic fungi isolated from agricultural environments were screened for their ability to tolerate and utilise Roundup in different cultural conditions as a nutritional source. Purpureocillium lilacinum was further screened to evaluate the ability to break down and utilise glyphosate as a P source in a liquid medium. The dose–response effect for Roundup, and the difference in toxicity between pure glyphosate and Roundup were also studied. This study reports the ability of several strains to tolerate 1 mM and 10 mM Roundup and to utilise it as nutritional source. P. lilacinum was reported for the first time for its ability to degrade glyphosate to a considerable extent (80%) and to utilise it as a P source, without showing dose-dependent negative effects on growth. Pure glyphosate was found to be more toxic than Roundup for P. lilacinum. Our results showed that pure glyphosate toxicity can be only partially addressed by the pH decrease determined in the culture medium. In conclusion, our study emphasises the noteworthy potential of P. lilacinum in glyphosate degradation.

Iron Overload Decreases Engraftment of Mice Receiving Allogeneic or Syngeneic Bone Marrow Transplant

Background:Transfusional iron overload is a poor prognostic factor in patients undergoing hematopoietic stem cell transplantation (HSCT). In multiple clinical studies, elevated serum ferritin correlated with inferior transplant outcomes; however, ferritin is an imperfect marker of iron burden and may not correlate with other markers, such as liver iron content. These studies are also confounded because increased transfusional need often reflects more severe disease, an independent predictor of worse outcome. Thus, it remains unclear whether the correlation between iron status and transplant outcome is due to transfusional iron overload alone, or is more reflective of other comorbidities. We developed a mouse model of parenteral iron overload followed by high dose chemotherapy and allogeneic or syngeneic HSCT to study, in isolation, the effects of iron overload on engraftment and survival after transplant.Methods:Cohorts of female C57BL/6 (H-2Kb) recipients received 0, 5, 25, or 50mg iron dextran, in divided doses over 2 weeks. Mice were then conditioned with busulfan (20mg/kg daily x 5 days) and cyclophosphamide (100mg/kg daily for the last 3 days). Two days later, mice received 30 x 106 bone marrow cells from female BALB/c (H-2Kd) donors (allogeneic HSCT) or 5 x 106 bone marrow cells from female UBC-GFP (H-2Kb) donors (syngeneic HSCT). Mice received enrofloxacin (10mg/kg daily x 5 days) after transplant. Engraftment was evaluated by flow cytometry as the proportion of donor cells in blood or bone marrow. Iron-related parameters were measured at the time of euthanasia (Day +28 post-transplant). Statistical analysis was performed with GraphPad Prism.Results:Our model of iron overload using iron dextran at escalating doses showed a dose-dependent increase in markers of iron load, such as total liver iron (R2=0.86) and ferritin (R2=0.84)(Fig. 1A-B; both P<0.0001 for linear trend). After allogeneic HSCT, there was a statistically significant decrease in overall survival in all groups receiving iron dextran (range: 47-63%), as compared to the saline control (90%)(Fig 1C; P<0.05); this effect was not dose-dependent. Data from 3 pooled experiments (N=30 mice per group) showed an engraftment rate of 59% in the saline group, and 47%, 42%, and 21% in the 5mg, 25mg, and 50mg iron dextran groups, respectively, suggesting a dose-dependent effect of iron overload on engraftment (Fig. 1D). In the syngeneic HSCT model, iron overload prior to transplant similarly resulted in delayed RBC and platelet engraftment and decreased rates of overall engraftment (Fig. 1E,F,G).Conclusions:Iron overload had a dose-dependent negative effect on overall engraftment after allogeneic and syngeneic HSCT. For allogeneic HSCT, there was also a decrease in overall survival in all the groups receiving iron dextran. For syngeneic HSCT, in which graft rejection cannot occur, iron overload still negatively affected post-transplant engraftment, suggesting that this effect is not due solely to potential immunomodulatory effects of excess iron on graft rejection. The mechanism(s) underlying the effects of iron overload on survival and engraftment rates in allogeneic and syngeneic HSCT, along with the potential benefit of chelation therapy, remain to be determined.Figure 1: Effect of iron overload on survival and engraftment. Mean ± S.D. for (A) total liver iron and (B) ferritin for allogeneic HSCT. Kaplan-Meier survival estimates for (C) mortality and (D) percent of mice not engrafting >50% of nucleated cells for allogeneic HSCT (N=10 mice per group per replicate; 30 mice total per group). Mean ± S.D. for (E) percent red cell engraftment over time and (F) percent platelet engraftment of time in syngeneic HSCT. Kaplan-Meier survival estimates for (F) percent of mice not engrafting >50% of red blood cells (N=10 mice per group per replicate; 20 mice total per group). *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001 as compared to the saline control or as specified. Arrow denotes day of transplant. [Display omitted] DisclosuresSpitalnik:New Health Sciences: Consultancy, Membership on an entity's Board of Directors or advisory committees.

Plant Feed Additives as Natural Alternatives to the Use of Synthetic Antioxidant Vitamins on Poultry Performances, Health, and Oxidative Status: A Review of the Literature in the Last 20 Years.

Plant feed additives (PFA) such as essential oils, extracts, and by-products from plant processing can be included in poultry diets. A total of 39 peer-reviewed articles were selected from the literature published in the last 20 years (2000–2020) comparing PFA antioxidant effects with synthetic antioxidant vitamins (mainly vitamin E) in poultry nutrition. The PFA can be used as an effective nutritional strategy to face poultry’s oxidative stress with positive impact also on their productivity and efficiency. They can partially or completely replace antioxidant synthetic vitamins (the latter administered at doses between 150 and 500 mg/kg) in animal diets, sometimes affecting important physiological functions or expressing synergistic effect with the synthetic antioxidants. It is crucial to take into consideration the issues related to the absorption and the metabolism of these additives and their interaction with gut microbiota. However, some form- and dose-dependent negative effects on growth performances are observed.

Mavacamten has a differential impact on force generation in myofibrils from rabbit psoas and human cardiac muscle.

Mavacamten (MYK-461) is a small-molecule allosteric inhibitor of sarcomeric myosins being used in preclinical/clinical trials for hypertrophic cardiomyopathy treatment. A better understanding of its impact on force generation in intact or skinned striated muscle preparations, especially for human cardiac muscle, has been hindered by diffusional barriers. These limitations have been overcome by mechanical experiments using myofibrils subject to perturbations of the contractile environment by sudden solution changes. Here, we characterize the action of mavacamten in human ventricular myofibrils compared with fast skeletal myofibrils from rabbit psoas. Mavacamten had a fast, fully reversible, and dose-dependent negative effect on maximal Ca2+-activated isometric force at 15°C, which can be explained by a sudden decrease in the number of heads functionally available for interaction with actin. It also decreased the kinetics of force development in fast skeletal myofibrils, while it had no effect in human ventricular myofibrils. For both myofibril types, the effects of mavacamten were independent from phosphate in the low-concentration range. Mavacamten did not alter force relaxation of fast skeletal myofibrils, but it significantly accelerated the relaxation of human ventricular myofibrils. Lastly, mavacamten had no effect on resting tension but inhibited the ADP-stimulated force in the absence of Ca2+. Altogether, these effects outline a motor isoform-specific dependence of the inhibitory effect of mavacamten on force generation, which is mediated by a reduction in the availability of strongly actin-binding heads. Mavacamten may thus alter the interplay between thick and thin filament regulation mechanisms of contraction in association with the widely documented drug effect of stabilizing myosin motor heads into autoinhibited states.

Non-viral Gene Delivery of Interleukin-1 Receptor Antagonist Using Collagen-Hydroxyapatite Scaffold Protects Rat BM-MSCs From IL-1β-Mediated Inhibition of Osteogenesis.

Although most bone fractures typically heal without complications, a small proportion of patients (≤10%) experience delayed healing or potential progression to non-union. Interleukin-1 (IL-1β) plays a crucial role in fracture healing as an early driver of inflammation. However, the effects of IL-1β can impede the healing process if they persist long after the establishment of a fracture hematoma, making it a promising target for novel therapies. Accordingly, the overall objective of this study was to develop a novel gene-based therapy that mitigates the negative effects of IL-1β-driven inflammation while providing a structural template for new bone formation. A collagen-hydroxyapatite scaffold (CHA) was used as a platform for the delivery of nanoparticles composed of pDNA, encoding for IL-1 receptor antagonist (IL-1Ra), complexed to the robust non-viral gene delivery vector, polyethyleneimine (PEI). Utilizing pDNA encoding for Gaussia luciferase and GFP as reporter genes, we found that PEI-pDNA nanoparticles induced a transient gene expression profile in rat bone marrow-derived mesenchymal stromal cells (BM-MSCs), with a transfection efficiency of 14.8 ± 1.8% in 2D. BM-MSC viability was significantly affected by PEI-pDNA nanoparticles as evaluated using CellTiter Blue; however, after 10 days in culture this effect was negligible. Transfection with PEI-pIL-1Ra nanoparticles led to functional IL-1Ra production, capable of antagonizing IL-1β-induced expression of secreted embryonic alkaline phosphatase from HEK-Blue-IL-1β reporter cells. Sustained treatment with IL-1β (0.1, 1, and 10 ng/ml) had a dose-dependent negative effect on BM-MSC osteogenesis, both in terms of gene expression (Alpl and Ibsp) and calcium deposition. BM-MSCs transfected with PEI-IL-1Ra nanoparticles were found to be capable of overcoming the inhibitory effects of sustained IL-1β (1 ng/ml) treatments on in vitro osteogenesis. Ultimately, IL-1Ra gene-activated CHA scaffolds supported mineralization of BM-MSCs under chronic inflammatory conditions in vitro, demonstrating potential for future therapeutic applications in vivo.

Effects of ZnO nanoparticles on flocculation and sedimentation of activated sludge in wastewater treatment process

Despite the behaviors of ZnO nanoparticles (ZnO NPs) in wastewater treatment processes have been widely explored, the impacts of ZnO NPs on the activated sludge's flocculation and sedimentation performances for solid-liquid separation have rarely been involved yet. In this study, ZnO NPs were observed to exert a dose-dependent negative effect on the sludge's flocculation performance but did not significantly impact the sludge’ sedimentation behaviors. Furthermore, it was NPs themselves rather than the dissolved Zn2+ who impaired on the sludge flocculation performance because the Zn2+ alone would not compromise the sludge's flocculation efficiency. In addition, the sludge flocculation performance was revealed to be inversely related to the extracellular polymeric substances (EPS) content in the sludge and the direct contacts between ZnO NPs and the cells in the sludge should be the prerequisite to stimulate the secretion of the sludge EPS. The poor sludge flocculation performance could also be caused by the reduced protein/polysaccharide (PN/PS) ratio and the zeta (ζ) potential in the loosely bound (LB-EPS) after the sludge exposure to ZnO NPs. Fourier transform-infrared spectra (FT-IR) and three dimensional - excitation emission fluorescence spectra (3D-EEM) analysis further revealed that the decrease of the tyrosine PN-like substance level in the LB-EPS was probably the key reason for the decreased PN/PS ratio and ζ potential in the LB-EPS, which eventually induced the decline of the sludge flocculation performance under the ZnO NP stress. These results could potentially expand the knowledge on sludge flocculation and sedimentation in the presence of ZnO NPs.

Eco-toxic effects of lead and nickel on survivability, reproduction and growth of earthworm (Eudrilus eugeniae)

The present study was carried out to determine the toxic effects of lead (Pb) and nickel (Ni) on the survivability, reproduction and growth of earthworm, Eudrilius eugeniae. Adult E. eugeniae were exposed to the varying concentrations of Pb and Ni. Mortality, growth and cocoon production were measured at every 30 days interval for 90 days. The results suggest clear dose-dependent negative effects of Pb and Ni on survivability, reproduction and growth of earthworms. A maximum reduction (43.35%) in survivability was observed in the case of Pb (0.06 ppm) followed by Ni+Pb (0.03+0.03 ppm) in which there is 31.65% decrement in survivability was observed. A similar trend was observed in growth and reproduction studies. It was concluded that the heavy metal Pb was more noxious to E. eugeniae as compared to Ni alone as well as in combinations. These results can be used for environmental monitoring and estimation of heavy metals contamination in soil.

Physiological aspects of rat activity, their anxiety and memory after administration of full gabaa-receptor complex agonist propoxazepam

The action of 7-bromo-5 (o-chlorophenyl) -3-propoxy-1,2-dihydro-3H-1,4-benzodiazepin-2-one (propoxazepam) with prolonged administration in various doses on behavioural reactions, anxiety and the memory of rats, as well as their muscle tone was estimated, which is important paying attention to its main (anticonvulsant and analgesic) pharmacological effects.The aim of the study was a comparative assessment of the severity and duration of propoxazepam effect after its administration to rats at doses of 2, 5 and 10 mg/kg (10 days) on higher functions of the central nervous system according to indicators such as motor and exploratory activity, as well as reference and working memory .Materials and methods. The study was conducted on 40 Wistar rats weighing 220-290 g. The psychophysiological state of the animals was evaluated using the open field test, the formation of spatial working and long-term memory in a eight-arm maze, muscle relaxation, imbalance and movements coordination - using the rotating rod method. Statistical processing was performed in Microsoft Excel 2016 with AtteStat 12.The results of the study. When comparing the test results of the open field, radial labyrinth and in groups of animals that were administered different doses of the compound, it was found that, in general, these parameters at doses of 2 mg/kg and 5 mg/kg statistically significantly different (increase) from control values, but are similar. At a dose of 10 mg/kg, most of the parameters (except for the rotarod test) for these animals were characterized by a downward trend.Conclusions. The administration of the drug in doses of 2, 5 and 10 mg/kg leads to a decrease in anxious behaviour of animals, which is also accompanied by a pronounced dose-dependent negative effect on the endurance, coordination and memory of animals. The administration of the drug at a dose of 10 mg/kg impaired the learning ability of animals and reduced memory function. This should be considered in clinical studies of the compound