ABSTRACT
Metastatic melanoma is an aggressive disease, despite recent improvements in therapy. Eradicating all melanoma cells even in drug-sensitive tumors is unsuccessful in patients because a subset of cells can transition to a slow-cycling state, rendering them resistant to most targeted therapy. It is still unclear what pathways define these subpopulations and promote this resistant phenotype. In the current study, we show that Wnt5A, a non-canonical Wnt ligand that drives a metastatic, therapy-resistant phenotype, stabilizes the half-life of p53 and uses p53 to initiate a slow-cycling state following stress (DNA damage, targeted therapy, and aging). Inhibiting p53 blocks the slow-cycling phenotype and sensitizes melanoma cells to BRAF/MEK inhibition. In vivo, this can be accomplished with a single dose of p53 inhibitor at the commencement of BRAF/MEK inhibitor therapy. These data suggest that taking the paradoxical approach of inhibiting rather than activating wild-type p53 may sensitize previously resistant metastatic melanoma cells to therapy.
Subject(s)
Melanoma/metabolism , Tumor Suppressor Protein p53/genetics , Wnt-5a Protein/metabolism , Cell Line, Tumor , Drug Resistance, Neoplasm/genetics , Humans , MAP Kinase Kinase Kinases/metabolism , Melanoma/genetics , Melanoma/pathology , Molecular Targeted Therapy , Mutation/drug effects , Protein Kinase Inhibitors/pharmacology , Proto-Oncogene Proteins B-raf/genetics , Proto-Oncogene Proteins B-raf/metabolism , Signal Transduction/drug effects , Sulfonamides/pharmacology , Tumor Microenvironment/drug effects , Tumor Suppressor Protein p53/physiologyABSTRACT
Naive human embryonic stem cells (hESCs) that resemble the pre-implantation epiblasts are fueled by a combination of aerobic glycolysis and oxidative phosphorylation, but their mitochondrial regulators are poorly understood. Here we report that, proline dehydrogenase (PRODH), a mitochondria-localized proline metabolism enzyme, is dramatically upregulated in naive hESCs compared to their primed counterparts. The upregulation of PRODH is induced by a reduction in c-Myc expression that is dependent on PD0325901, a MEK inhibitor routinely present in naive hESC culture media. PRODH knockdown in naive hESCs significantly promoted mitochondrial oxidative phosphorylation (mtOXPHOS) and reactive oxygen species (ROS) production that triggered autophagy, DNA damage, and apoptosis. Remarkably, MitoQ, a mitochondria-targeted antioxidant, effectively restored the pluripotency and proliferation of PRODH-knockdown naive hESCs, indicating that PRODH maintains naive pluripotency by preventing excessive ROS production. Concomitantly, PRODH knockdown significantly slowed down the proteolytic degradation of multiple key mitochondrial electron transport chain complex proteins. Thus, we revealed a crucial role of PRODH in limiting mtOXPHOS and ROS production, and thereby safeguarding naive pluripotency of hESCs.
Subject(s)
Oxidative Phosphorylation , Proline Oxidase , Humans , Reactive Oxygen Species/metabolism , Proline Oxidase/genetics , Proline Oxidase/metabolism , Mitochondria/metabolism , ApoptosisABSTRACT
OBJECTIVE: To investigate aquaporin-4 antibody (AQP4-IgG) dynamics and relapse risk in patients with seropositive neuromyelitis optica spectrum disorder treated with immunosuppressants. METHODS: This observational cohort study with prospectively collected data included 400 neuromyelitis optica spectrum disorder patients seropositive for AQP4-IgG and treated with immunosuppressants. Serum AQP4-IgG was detected by fixed cell-based assay every 6 months. RESULTS: After treatment with immunosuppressants, 128 patients became AQP4-IgG seronegative. The median time to become seronegative for 400 patients was 76.4 months (61.4 months, NA). Among those patients with negative change of AQP4-IgG, the mean annualized relapse rate significantly decreased after patients became seronegative (0.20 vs 0.77, p < 0.001), and a positive correlation was observed between time to become seronegative and relapse (OR 1.018, 95% CI 1.001-1.035, p < 0.05). Independent risk factors for AQP4-IgG becoming seronegative were older age at onset, initiation of immunosuppressants at onset, and shorter disease duration before maintenance therapy. Independent risk factors for relapse included younger age (≤46.4 years) at onset, poly-system involvement in the first attack, and unchanged or increased AQP4-IgG titer. The relapse risk was not associated with sex, combination with connective tissue disease, seropositivity for systemic autoimmune antibodies, or incomplete recovery from the first attack. INTERPRETATION: Patients with younger age at onset, poly-system involvement in the first attack, and unchanged or increased titer of AQP4-IgG are most likely to experience relapse under treatment with immunosuppressants. Time to AQP4-IgG becoming seronegative and change of AQP4-IgG titer may become the surrogate efficacy biomarkers in clinical trials. ANN NEUROL 2023;93:1069-1081.
Subject(s)
Neuromyelitis Optica , Humans , Middle Aged , Immunosuppressive Agents/therapeutic use , Aquaporin 4 , Autoantibodies , Chronic Disease , Biomarkers , Recurrence , Immunoglobulin GABSTRACT
Melioidosis is a severe infectious disease caused by Burkholderia pseudomallei, an intracellular pathogen with a high mortality rate and significant antibiotic resistance. The high mortality rate and resistance to antibiotics have drawn considerable attention from researchers studying melioidosis. This study evaluated the effects of various concentrations (75, 50, and 25 µg/mL) of promethazine hydrochloride (PTZ), a potent antihistamine, on biofilm formation and lipase activity after 24 h of exposure to B. thailandensis E264. A concentration-dependent decrease in both biofilm biomass and lipase activity was observed. RT-PCR analysis revealed that PTZ treatment not only made the biofilm structure loose but also reduced the expression of btaR1, btaR2, btaR3, and scmR. Single gene knockouts of quorum sensing (QS) receptor proteins (∆btaR1, ∆btaR2, and ∆btaR3) were successfully constructed. Deletion of btaR1 affected biofilm formation in B. thailandensis, while deletion of btaR2 and btaR3 led to reduced lipase activity. Molecular docking and biological performance results demonstrated that PTZ inhibits biofilm formation and lipase activity by suppressing the expression of QS-regulated genes. This study found that repositioning PTZ reduced biofilm formation in B. thailandensis E264, suggesting a potential new approach for combating melioidosis.
Subject(s)
Biofilms , Burkholderia , Drug Repositioning , Promethazine , Biofilms/drug effects , Biofilms/growth & development , Burkholderia/drug effects , Burkholderia/physiology , Burkholderia/genetics , Promethazine/pharmacology , Molecular Docking Simulation , Anti-Bacterial Agents/pharmacology , Lipase/metabolism , Lipase/genetics , Gene Expression Regulation, Bacterial/drug effects , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Humans , Quorum Sensing/drug effectsABSTRACT
Endophytic fungi associated with plants may contain undiscovered bioactive compounds. Under standard laboratory conditions, most undiscovered compounds are inactive, whereas their production could be stimulated under different cultivation conditions. In this study, six endophytic fungi were isolated from the bark of Koelreuteria paniculata in Quancheng Park, Jinan City, Shandong Province, one of which was identified as a new subspecies of Aureobasidium pullulans, named A. pullulans KB3. Additionally, metabolomic tools were used to screen suitable media for A. pullulans KB3 fermentation, and the results showed that peptone dextrose medium (PDM) was more beneficial to culture A. pullulans KB3 for isolation of novel compounds. Sphaerolone, a polyketone compound, was initially isolated from A. pullulans KB3 via scaled up fermentation utilizing PDM. Additionally, the whole-genome DNA of A. pullulans KB3 was sequenced to facilitate compound isolation and identify the biosynthesis gene clusters (BGCs). This study reports the multi-omics (metabolome and genome) analysis of A. pullulans KB3, laying the foundation for discovering novel compounds of silent BGCs and identifying their biosynthesis pathway.
ABSTRACT
An anti-neuroinflammatory activities-guided phytochemical research of Wikstroemia lungtzeensis was performed for the first time. Three undescribed carotane-type sesquiterpenes, excoecafolinols C-E (1-3), and nine known sesquiterpene derivatives were isolated from the effective ethyl acetate extract of W. lungtzeensis. Their structures were determined based on multiple spectroscopic techniques and electronic circular dichroism (ECD) spectra. Furthermore, the anti-neuroinflammatory activities of the identified compounds were evaluated in lipopolysaccharide-stimulated BV-2 cells. Among them, six components (1, 2, 4, 7, 11, 12) exhibited significant inhibitory effects on nitric oxide (NO) production, with IC50 values ranging from 10.48 to 49.41 µM (positive control minocycline, IC50 53.20 µM). Carotane-type sesquiterpenes (1, 2, 4) with high content and significant inhibitory effects, are considered to be major active ingredients of W. lungtzeensis, which might serve as potential therapeutic agents for neurodegenerative diseases.
ABSTRACT
Biological evidence is relatively common evidence in criminal cases, and it has strong probative power because it carries DNA information for individual identification. At the scene of fire-related cases, the complex thermal environment, the escape of trapped people, the firefighting and rescue operations, and the deliberate destruction of criminal suspects will all affect the biological evidence in the fire scene. Scholars at home and abroad have explored and studied the effectiveness of biological evidence identification in fire scenes, and found that the blood stains, semen stains, bones, etc. are the main biological evidence which can be easily recovered with DNA in fire scenes. In order to analyze the research status and development trend of biological evidence in fire scenes, this paper systematically sorts out the relevant research, mainly including the soot removal technology, appearance method of typical biological evidence, and possibility of identifying other biological evidence. This paper also prospects the next step of research direction, in order to provide reference for the identification of biological evidence and improve the value of biological evidence in fire scenes.
Subject(s)
Blood Stains , Body Fluids , Fires , Humans , Semen , DNA/geneticsABSTRACT
OBJECTIVES: To analyze the high risk factors of obstetric brachial plexus palsy (OBPP), and to explore how to evaluate the relationship between fault medical behavior and OBPP in the process of medical damage forensic identification. METHODS: A retrospective analysis was carried out on 25 cases of medical damage liability disputes related to OBPP from 2017 to 2021 in Beijing Fayuan Judicial Science Evidence Appraisal Center. The shortcomings of hospitals in birth weight assessment, delivery mode selection, labor process observation and shoulder dystocia management, and the causal relationship between them and the damage consequences of the children were summarized. RESULTS: Fault medical behavior was assessed as the primary cause in 2 cases, equal cause in 10 cases, secondary cause in 8 cases, minor cause in 1 case, no causal relationship in 1 case, and unclear causal force in 3 cases. CONCLUSIONS: In the process of forensic identification of OBPP, whether medical behaviors fulfill diagnosis and treatment obligations should be objectively analyzed from the aspects of prenatal evaluation, delivery mode notification, standardized use of oxytocin, standard operation of shoulder dystocia, etc. Meanwhile, it is necessary to fully consider the objective risk of different risk factors and the difficulty of injury prevention, and comprehensively evaluate the causal force of fault medical behavior in the damage consequences.
Subject(s)
Brachial Plexus Neuropathies , Brachial Plexus , Paralysis, Obstetric , Shoulder Dystocia , Pregnancy , Female , Child , Humans , Retrospective Studies , Paralysis, Obstetric/etiology , Brachial Plexus Neuropathies/etiology , Brachial Plexus Neuropathies/complications , Risk Factors , Paralysis/complicationsABSTRACT
We compared commonly used BAPTA-derived chemical Ca2+ dyes (fura2, Fluo-4, and Rhod-2) with a newer genetically encoded indicator (R-GECO) in single cell models of the heart. We assessed their performance and effects on cardiomyocyte contractility, determining fluorescent signal-to-noise ratios and sarcomere shortening in primary ventricular myocytes from adult mouse and guinea pig, and in human iPSC-derived cardiomyocytes. Chemical Ca2+ dyes displayed dose-dependent contractile impairment in all cell types, and we observed a negative correlation between contraction and fluorescence signal-to-noise ratio, particularly for fura2 and Fluo-4. R-GECO had no effect on sarcomere shortening. BAPTA-based dyes, but not R-GECO, inhibited in vitro acto-myosin ATPase activity. The presence of fura2 accentuated or diminished changes in contractility and Ca2+ handling caused by small molecule modulators of contractility and intracellular ionic homeostasis (mavacamten, levosimendan, and flecainide), but this was not observed when using R-GECO in adult guinea pig left ventricular cardiomyocytes. Ca2+ handling studies are necessary for cardiotoxicity assessments of small molecules intended for clinical use. Caution should be exercised when interpreting small molecule studies assessing contractile effects and Ca2+ transients derived from BAPTA-like chemical Ca2+ dyes in cellular assays, a common platform for cardiac toxicology testing and mechanistic investigation of cardiac disease physiology and treatment.
Subject(s)
Induced Pluripotent Stem Cells , Myocytes, Cardiac , Animals , Guinea Pigs , Humans , Mice , Calcium/metabolism , Coloring Agents/metabolism , Coloring Agents/pharmacology , Induced Pluripotent Stem Cells/metabolism , Myocardial Contraction , Myocytes, Cardiac/metabolism , SwineABSTRACT
Species may cope with warming through both rapid evolutionary and plastic responses. While thermal performance curves (TPCs), reflecting thermal plasticity, are considered powerful tools to understand the impact of warming on ectotherms, their rapid evolution has been rarely studied for multiple traits. We capitalized on a 2-year experimental evolution trial in outdoor mesocosms that were kept at ambient temperatures or heated 4°C above ambient, by testing in a follow-up common-garden experiment, for rapid evolution of the TPCs for multiple key traits of the water flea Daphnia magna. The heat-selected Daphnia showed evolutionary shifts of the unimodal TPCs for survival, fecundity at first clutch and intrinsic population growth rate toward higher optimum temperatures, and a less pronounced downward curvature indicating a better ability to keep fitness high across a range of high temperatures. We detected no evolution of the linear TPCs for somatic growth, mass and development rate, and for the traits related to energy gain (ingestion rate) and costs (metabolic rate). As a result, also the relative thermal slope of energy gain versus energy costs did not vary. These results suggest the overall (rather than per capita) top-down impact of D. magna may increase under rapid thermal evolution.
Subject(s)
Daphnia , Hot Temperature , Animals , Daphnia/physiology , Fertility , Phenotype , Population Growth , TemperatureABSTRACT
OBJECTIVE: To study the effects of vitamin D supplementation on physical growth and neurologic development of very preterm infants receiving nesting intervention in the neonatal intensive care unit (NICU). METHODS: A total of 196 preterm infants had been hospitalized in NICU with the gestational age (GA) between 28 and 32 weeks. Among them, 98 preterm infants received nesting intervention, and the other 98 cases received both nesting and vitamin D supplementation (400 IU). The interventions were continued until 36 weeks postmenstrual age (PMA). The 25(OH)D serum levels, anthropometric parameters, and Premie-Neuro (PN) scores were compared at 36 weeks PMA. RESULTS: Higher median serum level of 25(OH)D was found in the nesting + vitamin D [38.40 ng/mL (IQR: 17.20 ~ 70.88) ng/mL] as compared to the nesting group [15.95 ng/mL (IQR: 10.80 ~ 24.30) ng/mL] at 36 weeks PMA. Besides, infants receiving combined nesting intervention and vitamin D supplementation had less proportion of vitamin D deficiency [VDD, 25(OH)D levels < 20 ng/mL] than those receiving nesting intervention alone. After intervention, the anthropometric parameters of infants, including weight, length, BMI and head circumference were improved in the nesting + vitamin D group as compared to the nesting group at 36 weeks PMA, with higher scores of neurological, movement and responsiveness. CONCLUSIONS: Vitamin D supplementation effectively decreased the prevalence of VDD and led to higher concentrations of 25(OH)D at 36 weeks PMA. This was one more study that supported the necessity of vitamin D supplementation to improve physical growth and neurologic development of preterm-born newborns who received nesting intervention in the NICU.
Subject(s)
Infant, Premature , Vitamin D Deficiency , Infant , Female , Infant, Newborn , Humans , Intensive Care Units, Neonatal , Vitamin D/therapeutic use , Vitamins , Dietary SupplementsABSTRACT
Olive oil is an important and popularly used plant oil in the daily diet or chemical industry. Due to its biological benefits on human health and higher selling prices, adulteration of olive oil for commercial fraud by other plant oils is becoming a serious issue. In this study, a specific, sensitive and rapid loop-mediated isothermal amplification (LAMP) was first developed for the detection of Olea europaea DNA for olive oil authentication. The oleosin gene was used for the primer design of the LAMP assay. After primer validation, the results showed that the LAMP primers were specific and rapid to isothermally authenticate the oleosin gene of Olea europaea within 1 h at 62 °C and had no cross-reaction with other DNA of plant oils. The sensitivity of LAMP was 1 ng of genomic DNA in olive oil, and only 1% olive oil in the sample was requisite during DNA amplification. Additionally, positive detection by LAMP in all the collected commercial olive oil products was practically performed but not in PCR assays. In conclusion, herein, the established LAMP assay with specificity could not only be capable for rapid identification but also applicable for olive oil authentication for precluding adulteration in plant oil products. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05726-y.
ABSTRACT
OBJECTIVES: To establish a new method for evaluating the brain maturation of preterm infants based on the features of electroencephalographic activity. METHODS: A prospective study was conducted on the video electroencephalography (vEEG) and amplitude-integrated electroencephalography (aEEG) recordings within 7 days after birth of preterm infants who had a postmenstrual age (PMA) of 25-36 weeks and met the inclusion criteria. The background activity of aEEG+conventional electroencephalography (cEEG) was scored according to the features of brain maturation as a new evaluation system and was compared with the aEEG evaluation system. The correlations of the evaluation results of the two methods with gestational age (GA), PMA, and head circumference were evaluated. The intervals of the total scores of aEEG+cEEG and aEEG were calculated for preterm infants with different PMAs and were compared between groups. The consistency of the new scoring system was evaluated among different raters. RESULTS: A total of 52 preterm infants were included. The total scores of aEEG+cEEG and aEEG were positively correlated with GA, PMA, and head circumference (P<0.05), and the correlation coefficient between the total scores of the two systems and PMA and GA was >0.9. The normal score intervals for aEEG+cEEG and aEEG scoring systems were determined in preterm infants with different PMAs as follows: infants with a PMA of less than 28 weeks had scores of 13.0 (11.0, 14.0) points for aEEG+cEEG and 6.0 (4.0, 7.0) points for aEEG; infants with a PMA between 28 and 29+6 weeks had scores of 16.0 (14.5, 17.0) points for aEEG+cEEG and 8.0 (6.0, 8.0) points for aEEG; infants with a PMA between 30 and 31+6 weeks had scores of 18.0 (17.0, 21.0) points for aEEG+cEEG and 9.0 (8.0, 10.0) points for aEEG; infants with between 32 and 33+6 weeks had scores of 22.0 (20.0, 24.5) points for aEEG+cEEG and 10.0 (10.0, 10.8) points for aEEG; infants with a PMA between 34 and 36 weeks had scores of 26.0 (24.5, 27.5) points for aEEG+cEEG and 11.0 (10.0, 12.0) points for aEEG. There were significant differences in the total scores of aEEG+cEEG and aEEG among the different PMA groups (P<0.05). There was a high consistency between different raters when using the scoring system to evaluate the brain maturation of preterm infants (κ=0.86). CONCLUSIONS: The aEEG+cEEG scoring system established in this study can quantitatively reflect the brain maturation of preterm infants, with a good discriminatory ability between preterm infants with different PMAs and high consistency between different raters.
Subject(s)
Electroencephalography , Infant, Premature , Humans , Infant, Newborn , Brain , Gestational Age , Prospective StudiesABSTRACT
OBJECTIVES: To explore a new method for electroencephalography (EEG) background analysis in neonates with hypoxic-ischemic encephalopathy (HIE) and its relationship with clinical grading and head magnetic resonance imaging (MRI) grading. METHODS: A retrospective analysis was performed for the video electroencephalography (vEEG) and amplitude-integrated electroencephalography (aEEG) monitoring data within 24 hours after birth of neonates diagnosed with HIE from January 2016 to August 2022. All items of EEG background analysis were enrolled into an assessment system and were scored according to severity to obtain the total EEG score. The correlations of total EEG score with total MRI score and total Sarnat score (TSS, used to evaluate clinical gradings) were analyzed by Spearman correlation analysis. The total EEG score was compared among the neonates with different clinical gradings and among the neonates with different head MRI gradings. The receiver operating characteristic (ROC) curve and the area under thecurve (AUC) were used to evaluate the value of total EEG score in diagnosing moderate/severe head MRI abnormalities and clinical moderate/severe HIE, which was then compared with the aEEG grading method. RESULTS: A total of 50 neonates with HIE were included. The total EEG score was positively correlated with the total head MRI score and TSS (rs=0.840 and 0.611 respectively, P<0.001). There were significant differences in the total EEG score between different clinical grading groups and different head MRI grading groups (P<0.05). The total EEG score and the aEEG grading method had an AUC of 0.936 and 0.617 respectively in judging moderate/severe head MRI abnormalities (P<0.01) and an AUC of 0.887 and 0.796 respectively in judging clinical moderate/severe HIE (P>0.05). The total EEG scores of ≤6 points, 7-13 points, and ≥14 points were defined as mild, moderate, and severe EEG abnormalities respectively, which had the best consistency with clinical grading and head MRI grading (P<0.05). CONCLUSIONS: The new EEG background scoring method can quantitatively reflect the severity of brain injury and can be used for the judgment of brain function in neonates with HIE.
Subject(s)
Brain Injuries , Hypoxia-Ischemia, Brain , Infant, Newborn , Humans , Hypoxia-Ischemia, Brain/diagnostic imaging , Retrospective Studies , Electroencephalography , ROC CurveABSTRACT
SOX2, a well-established pluripotency factor supporting the self-renewal of pluripotent stem cells (PSCs), is also a crucial factor for maintaining the properties and functionalities of neural progenitor cells (NPCs). It regulates the transcription of target genes by forming complexes with its partner factors, but systematic comparison of SOX2 binding partners in human PSCs versus NPCs is lacking. Here, by deciphering and comparing the SOX2-protein interactomes in human embryonic stem cells (hESCs) versus the NPCs derived from them, we identified 23 proteins with high reproducibility that are most differentially associated with SOX2, of which 9 are DNA repair proteins (PARP1, PARP2, PRKDC, XRCC1, XRCC5, XRCC6, RPA1, LIG3, DDB1). Genetic knocking-down or pharmacological inhibiting two of the DNA repair proteins (PARP1 and PRKDC) significantly up-regulated certain NPC or ectodermal biomarkers that are transcriptionally-suppressed by the SOX2/DNA repair protein complexes. These findings point to a crucial role of DNA repair proteins in pluripotent state transition and neural induction.
Subject(s)
DNA Repair , DNA-Activated Protein Kinase/genetics , DNA-Binding Proteins/genetics , Human Embryonic Stem Cells/metabolism , Neural Stem Cells/metabolism , SOXB1 Transcription Factors/genetics , Animals , Cell Differentiation/drug effects , Cell Line , Computational Biology/methods , DNA-Activated Protein Kinase/antagonists & inhibitors , DNA-Activated Protein Kinase/metabolism , DNA-Binding Proteins/antagonists & inhibitors , DNA-Binding Proteins/metabolism , Gene Expression Profiling , Gene Expression Regulation , Gene Regulatory Networks , Human Embryonic Stem Cells/cytology , Human Embryonic Stem Cells/drug effects , Humans , Neural Stem Cells/cytology , Neural Stem Cells/drug effects , Phthalazines/pharmacology , Piperazines/pharmacology , Purines/pharmacology , Pyrans/pharmacology , SOXB1 Transcription Factors/metabolism , Signal Transduction , Triazoles/pharmacologyABSTRACT
Warming and eutrophication negatively affect freshwater ecosystems by modifying trophic interactions and increasing water turbidity. We need to consider their joint effects on predator-prey interactions and how these depend on the thermal evolution of both predator and prey. We quantified how 4°C warming and algae-induced turbidity (that integrates turbidity per se and increased food for zooplankton prey) affect functional response parameters and prey population parameters in a common-garden experiment. We did so for all combinations of high- and low-latitude predator (damselfly larvae) and prey (water fleas) populations to assess the potential impact of thermal evolution of predators and/or prey at a high latitude under warming using a space-for-time substitution. We then modelled effects on the system stability (i.e. tendency to oscillate) under different warming, turbidity and evolutionary scenarios. Warming and turbidity had little effect on the functional response parameters of high-latitude predators. In contrast, warming and turbidity reduced the handling times of low-latitude predators. Moreover, warming increased the search rates of low-latitude predators in clear water but instead decreased these in turbid water. Warming increased stability (i.e. prevented oscillations) in turbid water (except for the 'high-latitude predator and high-latitude prey' system), mainly by decreasing the prey's carrying capacity and partly also by decreasing search rates, while it did not affect stability in clear water. Algae-induced turbidity generally decreased stability, mainly by increasing the prey's carrying capacity and partly also by increasing search rates. This resembles findings that nutrient enrichment can reduce the stability of trophic systems. The expected stability of the high-latitude trophic system under warming was dependent on the turbidity level: our results suggest that thermal plasticity tends to destabilize the high-latitude trophic system under warming in clear water but not in turbid water, and that thermal evolution of the predator will stabilize the high-latitude system under warming in turbid water but less so in clear water. The extent to which thermal plasticity and evolution shape trophic system stability under warming may strongly differ between clear and turbid water bodies, with their contributions having a more stabilizing role in turbid water.
Subject(s)
Ecosystem , Predatory Behavior , Animals , Food Chain , Fresh Water , Larva , ZooplanktonABSTRACT
The infections caused by Pseudomonas aeruginosa are difficult to treat due to its multidrug resistance. A promising strategy for controlling P. aeruginosa infection is targeting the quorum sensing (QS) system. Actinomycin D isolated from the metabolite of endophyte Streptomyces cyaneochromogenes RC1 exhibited good anti-QS activity against P. aeruginosa PAO1. Actinomycin D (50, 100, and 200 µg/mL) significantly inhibited the motility as well as reduced the production of multiple virulence factors including pyocyanin, protease, rhamnolipid, and siderophores. The images of confocal laser scanning microscopy and scanning electron microscopy revealed that the treatment of actinomycin D resulted in a looser and flatter biofilm structure. Real-time quantitative PCR analysis showed that the expression of QS-related genes lasI, rhlI, rhlR, pqsR, pslA, and pilA were downregulated dramatically. The production of QS signaling molecules N-(3-oxododecanoyl)-L-homoserine lactone and N-butanoyl-L-homoserine lactone were also decreased by actinomycin D. These findings suggest that actinomycin D, a potent in vitro anti-virulence agent, is a promising candidate to treat P. aeruginosa infection by interfering with the QS systems.
Subject(s)
Quorum Sensing , Streptomyces , Anti-Bacterial Agents/metabolism , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/metabolism , Biofilms , Dactinomycin/metabolism , Dactinomycin/pharmacology , Endophytes/metabolism , Pseudomonas aeruginosa/metabolism , Streptomyces/genetics , Streptomyces/metabolism , Virulence Factors/geneticsABSTRACT
OBJECTIVES: To investigate the risk factors for acute kidney injury (AKI) after hematopoietic stem cell transplantation (HSCT) in children. METHODS: A retrospective analysis was performed on the medical data of 111 children who underwent HSCT from January 2018 to January 2020. A multivariate logistic regression analysis was used to identify the risk factors for AKI. The Kaplan-Meier survival analysis was used to compare the prognosis in children with different grades of AKI. RESULTS: Graft-versus-host disease (grade â ¡-â £) (OR=4.406, 95%CI: 1.501-12.933, P=0.007), hepatic veno-occlusive disease (OR=4.190, 95%CI: 1.191-14.740, P=0.026), and thrombotic microangiopathy (OR=10.441, 95%CI: 1.148-94.995, P=0.037) were closely associated with the development of AKI after HSCT. The children with stage â ¢ AKI had a lower 1-year survival rate than those without AKI or with stage â AKI or stage â ¡ AKI (28.6%±12.1% vs 82.8%±5.2%/81.7%±7.4%/68.8%±11.6%; P<0.05). CONCLUSIONS: Children with stage â ¢ AKI after HSCT have a higher mortality rate. Graft-versus-host disease, hepatic veno-occlusive disease, and thrombotic microangiopathy are closely associated with the development of AKI after HSCT.
Subject(s)
Acute Kidney Injury , Graft vs Host Disease , Hematopoietic Stem Cell Transplantation , Thrombotic Microangiopathies , Child , Humans , Retrospective Studies , Hematopoietic Stem Cell Transplantation/adverse effects , Graft vs Host Disease/complications , Risk Factors , Acute Kidney Injury/etiology , Acute Kidney Injury/therapy , Thrombotic Microangiopathies/complicationsABSTRACT
Many species that are moving polewards encounter novel thermal regimes to which they have to adapt. Therefore, rapid evolution of thermal tolerance and of thermal plasticity in fitness-related traits in edge populations can be crucial for the success and speed of range expansions. We tested for adaptation in cold tolerance and in life history, behavioural and physiological traits and their thermal plasticity during a poleward range expansion. We reconstructed the thermal performance curves of life history (survival, growth and development rates), behaviour (food intake) and cold tolerance (chill coma recovery time) in the aquatic larval stage of the damselfly Ischnura elegans that is currently showing a poleward range expansion in northern Europe. We studied larvae from three edge and three core populations using a common-garden experiment. Consistent with the colder annual temperatures, larvae at the expansion front evolved an improved cold tolerance. The edge populations showed no overall (across temperatures) evolution of a faster life history that would improve their range-shifting ability. Moreover, consistent with damselfly edge populations from colder latitudes, edge populations evolved at the highest rearing temperature (28°C) a faster development rate, likely to better exploit the rare periods with higher temperatures. This was associated with a higher food intake and a lower metabolic rate. In conclusion, our results suggest that the edge populations rapidly evolved adaptive changes in trait means and thermal plasticity to the novel thermal conditions at the edge front. Our results highlight the importance of considering besides trait plasticity and the evolution of trait means, also the evolution of trait plasticity to improve forecasts of responses to climate change.
Durante su expansión hacia los polos, las especies encuentran nuevos regímenes de temperatura a los que tienen que adaptarse. Por esto, una rápida evolución de la tolerancia térmica y de la plasticidad térmica de rasgos fisiológicos clave en las poblaciones del borde del área de distribución es crucial para el éxito y la velocidad de las expansiones de rango. En este estudio testamos la adaptación de la tolerancia la frío y la plasticidad térmica de rasgos de historia de vida, comportamiento y fisiológicos durante una expansión de rango hacia el norte. Reconstruimos las curvas de rendimiento térmico de rasgos de historia de vida (supervivencia, tasa de crecimiento y tasa de desarrollo) y comportamiento (ingestión de alimento), así como la tolerancia al frío (tiempo de recuperación del coma por frío) en la larva acuática de la especie de caballito del diablo Ischnura elegans, especie que muestra un rango de expansión actual en el norte de Europa. Estudiamos larvas de tres poblaciones de la región de expansión norte y tres poblaciones de la región central usando experimentos en laboratorio. En concordancia con las temperaturas más bajas, las larvas del área de expansión mostraron mayor tolerancia al frío. Sin embargo, estas larvas no mostraron en general (a lo largo de las temperaturas estudiadas) evolución hacia una historia de vida más rápida, que aumentaría su habilidad para expandirse. Además, en consistencia con la menor temperatura de la región de expansión, las larvas presentaron mayor tasa de desarrollo a la temperatura experimental más alta (28°C), probablemente para explotar mejor los infrecuentes períodos con altas temperaturas en dicha región. Esto estuvo asociado con una mayor ingestión de alimento y una menor tasa metabólica. En conclusión, nuestros resultados sugieren que los valores medios y la plasticidad de los rasgos estudiados de las poblaciones del frente de expansión evolucionaron rápidamente para adaptarse a las nuevas condiciones térmicas en dicha región. Asimismo, nuestros resultados destacan la importancia de considerar, además de la media y plasticidad de los rasgos, la evolución de esta plasticidad, con el fin de mejorar las predicciones de las respuestas de las especies al cambio climático.