SEARCH · PubMed Health

Results for “Time-dependent changes”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources

PubMed1975

Physical and enzymatic properties of nucleotide-depleted beef heart mitochondrial adenosine triphosphatase.

Tightly bound adenine nucleotides are removed from multiple binding sites on beef heart mitochondrial ATPase (F1) by chromatography on columns of Sephadex equilibrated with 50% glycerol. Release of nucleotides from the enzyme is associated with large decreases in sedimentation velocity (from 11.9 S to 8.4 S) which may be observed in concentrated solutions of polyols. Polyol-induced conformational changes are reversed when the enzyme is returned to dilute buffers. The nucleotide-depleted enzyme restores oxidative phosphorylation in F1-deficient submitochondrial particles. Reconstitution of nucleotide-depleted F1 with the ATP analog (adenylyl-imidodiphosphate (AMP-PNP), almost 5 moles of AMP-PNP per mole of enzyme, results in preparations with substantially inhibited ATPase activity which nevertheless restores oxidative phosphorylation and the 32Pi-ATP exchange reaction in F1-deficient submitochondrial particles. Incubation of the analog-labeled enzyme with ATP and Mg++ results in partial displacement of the analog and a time-dependent recovery of ATPase activity.

Adenine Nucleotides↗

PubMed1977

Modification of pig heart lactate dehydrogenase with methyl methanethiosulphonate to produce an enzyme with altered catalytic activity.

Methyl methanethiosulphonate was used to produce a modification of the essential thiol group in lactate dehydrogenase which leaves the enzyme catalytically active. Methyl methanethiosulphonate produced a progressive inhibition of enzyme activity, with 2mM-pyruvate and 0.14mM-NADH as substrates, which ceased once the enzyme had lost 70-90% of its activity. In contrast, with 10mM-lactate and 0.4mM-NAD+ as substrates the enzyme was virtually completely inhibited. The observed inhibition was critically dependent on the chosen substrate concentration, since methanethiolation with methyl methanethiosulphonate resulted in a large decrease in affinity for pyruvate. At 0.14mM-NADH, methanethiolation increased the apparent KmPyr from from 40micronM for the control enzyme to 12mM for the modified enzyme. Steady-state kinetics showed that there was not a statistically significant change in either KmNADH or KsNADH. At saturating NADH and pyruvate concentrations, the Vmax. was virtually unaffected for the methanethiolated enzyme. However, a decrease in Vmax. was observed when the modified enzyme was incubated in dilute solution. The modification of lactate dehydrogenase by methyl methanethiosulphonate involved the active site, since inhibition was completely prevented by substrate-analogue pairs such as NADH and oxamate or NAD+ and oxalate. The formation of complexes between methanethiolated lactate dehydrogenase and substrates or substrate analogues can also be shown by re-activation experiments. The methanethiolated enzyme was re-activated in a time-dependent reaction by dithiothreitol and this was prevented by oxamate, by NADH and by NADH plus oxamate in increasing order of effectiveness. The results of this work are interpreted in terms of a role for the essential thiol group in the binding of substrates.

Animals↗

PubMed1978

In vitro histamine and serotonin release by radiographic contrast media (RCM). Complement-dependent and -independent release reaction and changes in ultrastructure of human blood cells.

Peripheral leucocytes and platelets from twenty healthy volunteers were incubated in vitro with radiographic contrast media (diatrizoate-Hypaque, iothalamate-Conray and iodipamide-Cholografin) under varying conditions. All radiographic contrast media (RCM) were able to induce histamine release from peripheral leucocytes and the release reaction was dose-dependent. There were individual differences in the sensitivity of leucocytes to different RCM. The highest values (up to 80% histamine release) were found with high concentrations (0.07-0.3 M) of diatrizoate. The addition of normal human serum (NHS) to the reaction mixture led to a further increase in histamine release (P is less than 0.01), probably due to complement activation. The mechanism seems to be mediated by proteins of the alternative pathway, because serum depleted of complement components (factor B, factor D, properdin) did not show this synergistic effect. IgG-depleted serum, however, was able to show the augmented release reaction. Washed platelets incubated with RCM released serotonin in a dose- and time-dependent reaction. The most powerful serotonin-releasing RCM was found to be iodipamide, which produced a release reaction in all people investigated at concentrations of 0.04-0.09 M, while diatrizoate and iothalamate were effective only in half of the tested individuals at high concentrations (0.3 and 0.2 M respectively). The addition of plasma proteins to the reaction mixture inhibited the serotonin release quantitatively. There was no difference in inhibitory potency between autologous and heterologous plasma or serum; sera depleted of various complement components showed similar effects as NHS. The serotonin release was not due to platelet lysis, as determined by the concentration of lactic dehydrogenase present in the supernatant during serotonin release. Incubation of the leucocytes with RCM produced ultrastructural changes, including degranulation of basophils, aggregation of platelets and infiltration of the aggregates by polymorphonuclear leucocytes. The most prominent changes were observed when complement was present in the reaction mixture.

Basophils↗

PubMed2026

Association between pembrolizumab-based therapy exposure and survival outcomes in metastatic or recurrent uterine carcinosarcoma: a multi-center real-world study.

OBJECTIVE: To evaluate the association between exposure to pembrolizumab-based therapy in the post-platinum setting and survival outcomes in patients with metastatic or recurrent uterine carcinosarcoma. METHODS: In this retrospective study, patients with metastatic or recurrent uterine carcinosarcoma treated at three tertiary centers between January 2008 and April 2025 were included. Patients received various treatment modalities after recurrence or progression in the post-platinum setting. Survival outcomes were analyzed according to whether patients were exposed to pembrolizumab-based therapy after recurrence or progression. Survival after recurrence and overall survival were evaluated using Kaplan-Meier analyses and Cox proportional hazards models. Additional analyses using inverse probability of treatment weighting, doubly robust methods, and time-dependent Cox models were performed. RESULTS: A total of 147 patients were included, of whom 42 (28.6%) received pembrolizumab-based therapy in the post-platinum setting. In multi-variable analyses, pembrolizumab-based therapy exposure was independently associated with improved survival after recurrence (hazard ratio 0.44, 95% confidence interval 0.24 to 0.83, p = .01) and overall survival (hazard ratio 0.48; 95% confidence interval 0.26 to 0.89, p =.02). Positive peritoneal washing cytology was independently associated with poorer survival outcomes. In time-dependent Cox analyses using inverse probability of treatment weighting, pembrolizumab-based therapy exposure remained significantly associated with improved survival after recurrence (hazard ratio 0.56, 95% confidence interval 0.33 to 0.96, p =.035), whereas the association with overall survival was no longer statistically significant. CONCLUSIONS: Exposure to pembrolizumab-based therapy in the post-platinum setting was associated with improved survival after recurrence in patients with metastatic or recurrent uterine carcinosarcoma. These findings support the potential clinical relevance of pembrolizumab-based therapy in the post-platinum setting and warrant further prospective validation.

Aged↗

PubMed2026

Multi-level Transcriptomic and Machine-learning Analyses Identify MZT1 as a Proliferation-associated Prognostic Marker in Lung Adenocarcinoma.

BACKGROUND/AIM: Lung adenocarcinoma (LUAD) exhibits substantial molecular heterogeneity and variable clinical outcomes, highlighting the need for biomarkers that reflect core tumor biological processes. Centrosome-associated proteins regulate mitotic fidelity and genome stability, yet their roles in LUAD remain incompletely defined. In this study, we systematically characterized mitotic spindle organizing protein 1 (MOZART1; MZT1) and related family members in LUAD. MATERIALS AND METHODS: We performed integrated analyses combining bulk transcriptomic datasets, survival modeling, gene set enrichment, immune deconvolution, machine-learning based prognostic modeling, and single-cell RNA sequencing. Expression patterns and clinical associations of MZT family genes were evaluated across pan-cancer and LUAD cohorts. RESULTS: MZT family genes were consistently upregulated in tumor tissues, with MZT1 showing the most robust expression pattern. Elevated MZT1 expression was significantly associated with reduced overall survival. Functional analyses revealed coordinated activation of proliferative and genome maintenance pathways, including G2/M checkpoint regulation, E2F and MYC signaling, and DNA repair. A multivariable analysis indicated that the prognostic association of MZT1 was reduced after adjusting for canonical proliferation markers, suggesting partial overlap with established proliferation signals. The LASSO-based Cox model demonstrated stable time-dependent predictive performance at 1-, 3-, and 5-year survival. Immune analyses indicated associations between MZT1 expression and tumor microenvironmental features. Single-cell analysis showed that MZT1 expression was predominantly enriched in malignant epithelial cells and associated with proliferative cellular states. Protein-level validation supported concordance with transcriptomic findings. CONCLUSION: MZT1 is a proliferation-associated marker that integrates clinical risk, transcriptional programs, cellular heterogeneity, and predictive modeling in LUAD, providing a potential framework for biomarker development and risk stratification.

Humans↗

PubMed2026

Integrative analysis of transcriptome and chromatin accessibility reveals promoter-proximal regulation and identifies candidate ABC transporters associated with cold stress responses in maize.

BACKGROUND: Low-temperature stress is a formidable environmental constraint that severely limits the growth and productivity of maize (Zea mays L.), particularly during the highly vulnerable early seedling stage. While cold tolerance is a critical agronomic objective, the integrated transcriptional and epigenetic regulatory mechanisms that govern this trait remain largely elusive. Characterizing these coordinated molecular networks is fundamental to the genetic enhancement of cold resilience in maize. METHODS: Using two maize inbred lines contrasting in chilling response (ZHB12 tolerant, B73 sensitive), we performed integrative time‑course RNA‑seq and ATAC‑seq to thoroughly and systematically characterize the precise dynamic interplay between gene expression and chromatin accessibility under cold stress conditions at the seedling stage. RESULTS: Physiological assessments confirmed that ZHB12 possesses superior cold tolerance, manifested by significantly attenuated electrolyte leakage and reduced foliar damage compared to B73. Transcriptomic profiling revealed a massive, time-dependent divergence in gene expression between the two genotypes, with a major regulatory transition identified at 24 h of cold exposure. Functional enrichment analysis demonstrated that ZHB12 preferentially activates a robust defense repertoire, including Photosystem II electron transport, diterpenoid biosynthesis, and ATP biosynthetic pathways. Notably, multiple ATP-binding cassette (ABC) transporter genes were coordinately upregulated under chilling, suggesting their potential involvement in cellular homeostasis. ATAC-seq analysis indicated that cold stress is associated with chromatin remodeling in ZHB12, with increased accessibility observed in proximal promoter regions. Integrative analysis identified a core set of dual-responsive genes, in which increased promoter accessibility coincided with transcriptional upregulation. These genes were predominantly enriched in transporter activity and transcriptional regulation, suggesting potential epigenetic link to the superior stress response of ZHB12. CONCLUSION: Our findings reveal extensive transcriptional and chromatin accessibility changes in ZHB12 under cold stress. The observed associations between promoter accessibility and gene activation, particularly in genes involved in transport processes, highlight candidate regulators potentially contributing to cold tolerance. This study provides a molecular framework and identifies high-value candidate genes that may inform future efforts in breeding cold-tolerant maize, pending functional validation.

Zea mays↗

PubMed1977

Mechanism of pigeon liver malic enzyme modification of histidyl residues by ethoxyformic anhydride.

Incubation of malic enzyme (L-malate:NADP+ oxidoreductase (oxaloacetate-decarboxylating), EC 1.1.1.40) with ethoxyformic anhydride caused the time-dependent loss of its ability to catalyze reactions requiring the nucleotide cofactor NADP+ or NADPH, such as the oxidative decarboxylase, the NADP+ - stimualted oxalacetate decarboxylase, the pyruvate reductase, and the pyruvate-medium proton exchange activities. Similar loss of oxidative decarboxylase and pyruvate reductase activities was affected by photo-oxidation in the presence of rose bengal. The inactivation of oxidative decarboxylase activity by ethoxyformic anhydride was accompanied by the reaction of greater than or equal to 2.3 histidyl residues per enzyme site and was strongly inhibited by NADP+. Ethoxyformylation also impaired the ability of malic enzyme to bind NADP+ or NADPH. These results support the involvement of histidyl residue(s) at the nucleotide binding site of malic enzyme.

Animals↗

PubMed2026

Time-Dependent Effects of Rapid-Acting Antidepressants in iPSC-Derived Neurons from Treatment-Resistant Depression and Healthy Volunteers.

UNLABELLED: Rapid-acting antidepressants like ketamine and serotonergic psychedelics show promise for treatment-resistant depression (TRD), but the molecular mechanisms that contribute to their therapeutic effects remain unclear. Induced pluripotent stem cells (iPSCs) offer a platform to model human cortical neurons and investigate drug effects in a human-relevant system. Here, iPSCs from individuals with TRD and healthy volunteers (HVs) were differentiated into mature cortical-like neurons and treated for six and 24 hours with agents being investigated as rapid-acting antidepressants, including (2R,6R)-hydroxynorketamine (HNK), psilocybin, lysergic acid diethylamide (LSD), and 2,5-Dimethoxy-4-iodoamphetamine (DOI). Bulk and single-cell RNA sequencing assessed global and cell-type-specific transcriptomic responses. Synaptic proteins were evaluated via Western blotting and immunocytochemistry. To validate translational relevance, transcriptomic results were compared to CSF proteomics from ketamine-treated HVs. Despite differing initial pharmacological targets, overall gene expression across all compounds was highly correlated at matched timepoints compared to vehicle control, suggesting shared downstream effects. Both glutamatergic and serotonergic drugs converged on pathways involving inflammation, mTORC1 signaling, and cellular growth. At the single-cell level, HNK showed distinct cell-type specific alterations: upregulation in excitatory neurons and concomitant downregulation of inhibitory neuron populations. Differentially expressed genes from HNK-treated neurons also overlapped with CSF proteomic signatures from ketamine-treated individuals, supporting the model's translational relevance. This study is the first to assess multiple putative rapid-acting antidepressants in parallel using an iPSC-derived neuron model. Both convergent and drug-specific changes in gene expression and pathway enrichment were observed across diverse compounds, supporting the use of human iPSC-derived neurons in antidepressant drug discovery. CLINICAL TRIAL REGISTRY: www.clinicaltrials.gov, NCT02484456.

Journal Article↗

PubMed2026

Time-dependent effects of rapid-acting antidepressants in iPSC-derived neurons from treatment-resistant depression and healthy volunteers.

Rapid-acting antidepressants like ketamine and serotonergic psychedelics show promise for treatment-resistant depression (TRD), but the molecular mechanisms that contribute to their therapeutic effects remain unclear. Induced pluripotent stem cells (iPSCs) offer a platform to model human cortical neurons and investigate drug effects in a human-relevant system. Here, iPSCs from individuals with TRD and healthy volunteers (HVs) were differentiated into mature cortical-like neurons and treated for six and 24 h with agents being investigated as rapid-acting antidepressants, including (2 R,6 R)-hydroxynorketamine (HNK), psilocybin, lysergic acid diethylamide (LSD), and 2,5-Dimethoxy-4-iodoamphetamine (DOI). Bulk and single-cell RNA sequencing assessed global and cell-type-specific transcriptomic responses. Synaptic proteins were evaluated via Western blotting and immunocytochemistry. To validate translational relevance, transcriptomic results were compared to CSF proteomics from ketamine-treated HVs. Despite differing initial pharmacological targets, overall gene expression across all compounds was highly correlated at matched timepoints compared to vehicle control, suggesting shared downstream effects. Both glutamatergic and serotonergic drugs converged on pathways involving inflammation, mTORC1 signaling, and cellular growth. At the single-cell level, (2 R,6 R)-HNK showed distinct cell-type specific alterations: upregulation in excitatory neurons and concomitant downregulation of inhibitory neuron populations. Differentially expressed genes from (2 R,6 R)-HNK-treated neurons also overlapped with CSF proteomic signatures from ketamine-treated individuals, supporting the model's translational relevance. This study is the first to assess multiple putative rapid-acting antidepressants in parallel using an iPSC-derived neuron model. Both convergent and drug-specific changes in gene expression and pathway enrichment were observed across diverse compounds, supporting the use of human iPSC-derived neurons in antidepressant drug discovery. Clinical Trial Registry: www.clinical trials.gov, NCT02484456.

Journal Article↗

PubMed2025

Longitudinal Multi-Organ Transcriptomic Atlas of Salt-Induced Hypertension.

BACKGROUND: Salt-sensitive hypertension is a prevalent and clinically significant subtype of hypertension, where increased dietary salt intake elevates blood pressure and causes injury to multiple organ systems. Despite extensive research, dynamic molecular changes and conserved versus organ-specific transcriptional programs in hypertensive multi-organ damage remain poorly understood. Defining complex molecular pathways both in a temporal sequence and in an organ-specific manner is essential for developing targeted, precision therapies to mitigate hypertensive disease burden. METHODS: We generated a longitudinal multi-organ transcriptomic atlas of salt-sensitive hypertension using RNA sequencing of kidney cortex, kidney medulla, heart, and liver from Dahl salt-sensitive rats across four disease stages. A comprehensive bioinformatic analysis mapped dynamic transcriptional programs, evaluated 50 biological pathways, and defined upstream regulators. Histological and biochemical assays complemented transcriptomic analysis, while integration with human genome-wide association studies (GWAS) and compound-transcriptome analysis provided translational insights and identified candidate therapeutics. RESULTS: Salt-induced hypertension elicited both shared and tissue-specific transcriptional programs that evolved with disease progression. The kidney medulla showed robust early immune activation with metabolic suppression, while the cortex exhibited transient metabolic activation before declining and initiating immune activation. The liver and heart showed time-dependent metabolic and inflammatory remodeling. Cross-organ comparisons revealed a shared early proliferative response that converged on proinflammatory and fibrotic signatures. Upstream regulator analysis identified 79 time- and tissue-specific transcription factors associated with gene expression dynamics. GWAS integration analysis revealed endocrine signaling, ion transport, lipid metabolism, and detoxification as conserved pathways across species, underscoring the translational relevance of the model and study. Predictive compound-transcriptome analyses identified kinase inhibitors targeting phosphoinositide 3-kinase, mechanistic target of rapamycin and cyclin-dependent kinases as top candidates to counteract maladaptive transcriptional programs. CONCLUSIONS: This study defines temporal and tissue-specific transcriptomic remodeling in salt-sensitive hypertension and highlights the need for precision interventions to prevent progressive organ damage.

Journal Article↗

PubMed1975

Mechanism of nucleotide inhibition of gonadotropin binding to cell membranes of bovine corpus luteum.

ATP, CTP, ADP, AMP, cyclic 3',5'-AMP (cAMP) and cyclic 3',5'-CMP (cCMP) effectively inhibited the specific binding of 125I-labelled human chorionic gonadotropin ([125I]HCG) to bovine corpus luteum cell membranes. This inhibition was observed with 2.5 X 10(-4) M to 1.0 X 10(-3) M nucleotide concentrations, regardless of the presence of a nucleotide regenerating system. Submaximal concentrations of combinations of the nucleotides were additive in inhibiting binding. The inhibition of [125I]HCG binding was observed when the nucleotides were added at the beginning of or during incubation or preincubation of the membranes with nucleotides. Preincubation of membranes with CTP and cAMP, subsequent washing and reincubation with hormone, showed time-dependent inhibition of [125I]HCG binding when the preincubation temperature was 38 degrees C but not at 4 degrees C. The concentrated supernates from nucleotides preincubated with membranes had no inhibitory effect on [125I]HCG binding to fresh membranes. In the absence of added nucleotides, [125I]HCG-membrane interaction had the following apparent binding constants: a Kd of 1.5 X 10(-10) M, 46.3 fmoles of binding sites per mg membrane protein, and rate constants for association and dissociation 4.0 X 10(6) M-1 sec-1 and 1.0 X 10(-3) sec-1, respectively. At steady state conditions of [125I]HCG binding, CTP inhibited [125I]HCG at lower concentrations of added hormone (less than 3 X 10(-9) M) whereas at higher concentrations, this nucleotide enhanced [125I]HCG binding. Scatchard analysis of the data revealed that inhibition and enhancement of [125I]HCG binding in the presence of CTP were due to lowered affinity of gonadotropin receptors (32-37) fold) and to exposure of new low-affinity binding sites for [125I]HCG, respectively. At non-steady-state conditions, nucleotides increased dissociation rates (80 to 100%) and decreased association rates (30 to 38%). The data appear to be compatible with the suggestion that the nucleotides may bind to sites in the membranes and subsequently induce conformational changes in membrane components, resulting in a decreased affinity of gonadotropin receptors. The physiological significance of these findings needs to be determined.

Adenosine Diphosphate↗

PubMed1978

Relief of coronary artery spasm by nitroglycerin: time-dependent variability in drug action.

The arteriographic distinction between a fixed atheromatous obstruction and localized vasospasm in the coronary artery is often decided by the response of the lesion to nitroglycerin. We studied the time course of nitroglycerin in four patients with coronary artery spasm as revealed by selective angiography. Following complete dissolution of a 0.6 mg tablet of nitroglycerin sublingually a slight increase in heart rate occurred as early as two minutes, variable changes in overall vessel diameter were observed within four minutes, but the localized spasm remained fixed. It was not until six minutes had elasped that reinjection showed disappearance of spasm and uniform patency of the vessel in all cases. These observations stress the importance of waiting an appropriate period of time (at least six minutes) following complete absorption of sublingual nitroglycerin before any conclusion can be rationally drawn regarding the nature of a stenotic lesion as seen angiographically.

Adult↗

PubMed2026

Distinct molecular responses to acute cold exposure revealed by comparative transcriptomic and metabolomic profiling in the bay scallop Argopecten irradians.

Acute cold stress can elicit distinct molecular responses even when bay scallop populations show similar phenotypic outcomes. We compared a seventh-generation fast-growing bay scallop line (BS) with a commercial control population (CC) during a 72-h acute cold exposure at -1 ± 0.3 °C. RNA-seq was used as the discovery layer, representative BS cold-responsive genes were evaluated by qRT-PCR, and paired LC-MS profiles provided a comparative metabolic layer. At baseline, 138 genes differed between BS and CC; after cold exposure, 134 of these baseline differences disappeared and 61 of 65 cold-state differences newly emerged. BS showed a larger transcriptomic response magnitude than CC, with 1129 cold-responsive genes compared with 28 genes in CC, and this ordering remained robust across multiple sensitivity analyses. Survival after 72 h was identical in BS and CC (83/90, 92.2% in each population). Biochemical responses were time-dependent and marker-specific: CAT, LZM, T-SOD and T-AOC showed population-by-time interactions, whereas GSH-Px and MDA did not, and the 72-h differences were not consistently favourable to BS. Metabolomic cold effects were strongly concordant between populations, and no feature showed a significant population-by-cold interaction. Features putatively assigned to arachidonic acid metabolism were enriched, but this provider-annotated pathway signal remains exploratory because authentic-standard confirmation was not performed. These findings indicate population-specific differences in molecular responsiveness but do not establish superior cold tolerance in BS.

Animals↗

PubMed2026

Seawater immersion reshapes the temporal dynamics of traumatic brain injury and reveals mitochondrial oxidative stress as a modifiable therapeutic target.

Traumatic brain injury (TBI) evolves through time-dependent secondary injury, but whether seawater (SW) immersion merely amplifies pathology or reshapes the temporal trajectory of post-traumatic biology remains unclear. Here, we applied time-resolved proteomics to mouse brains after controlled cortical impact (CCI) with or without artificial SW immersion at 1, 3, 7, and 28 days post-injury. Trajectory-based proteomic analysis revealed that SW immersion altered the direction, magnitude, timing, persistence, and recovery of protein responses, rather than simply intensifying TBI-induced changes. This remodeled trajectory exhibited phase-specific patterns, including SW-dominant, synergistically enhanced, and attenuated responses, highlighting mitochondrial oxidative stress, inflammatory activation, complement/coagulation disturbance, and impaired structural repair. Phenotypic validation confirmed phase-specific deficits, including acute inflammatory-redox injury, impaired neuronal survival, chronic axon-myelin disruption, and incomplete behavioral recovery. SS-31 partially mitigated selected inflammatory, redox, neuronal, and white matter abnormalities, supporting mitochondrial oxidative stress as a modifiable node rather than the sole driver of trajectory remodeling. These findings identify seawater immersion as a temporal modifier of secondary injury and emphasize that environmental trauma may require trajectory-informed, phase-specific therapeutic interventions.

Animals↗

PubMed2026

Time- and Dose-Resolved DIA-PASEF Proteomics Maps the Transition from Adaptive Stress to Apoptotic Collapse in Melittin-Treated MDA-MB-231 Cells.

Melittin, the cytolytic peptide of honeybee venom, exhibits potent anticancer activity in triple-negative breast cancer (TNBC), yet the molecular programs underlying its cytotoxic effects remain incompletely defined. To address this gap, MDA-MB-231 TNBC cells were exposed to melittin at half-maximal inhibitory concentration(half IC50) and IC50 across early(0.5, 1, and 2 h), mid(3, 4 h), and late (12, 24 h) time windows. Proteomic profiling was performed using label-free data-independent acquisition(DIA) parallel accumulation-serial fragmentation(PASEF). Approximately 5800 proteins were quantified, revealing distinct dose-dependent stress responses. An integrative exploratory framework combining time-resolved log2 fold-change trajectories, area-under-the-curve(AUC) based temporal prioritization, and independent heatmap visualization identified proteins associated with melittin-induced stress remodeling. Half IC50 exposure showed a transient stress-adaptive signature characterized by chromatin remodeling(HMGN2, H2AZ1), structural and RNA-associated buffering(LRRC7), and indirect mitochondrial quality-control signaling(CPAMD8, SPATA4), which progressively weakened over time. In contrast, IC50 treatment induced rapid chromatin remodeling dominated by histone H1 variants(H1.4, H1.2), early RNA instability(LRRC7), and late-stage cytoskeletal disassembly marked by MICAL3 induction, consistent with progression toward apoptosis. These trajectories paralleled dose-dependent apoptotic phenotypes. Overall, data suggest that melittin elicits dose- and time-dependent proteomic stress responses in TNBC cells and identify candidate trajectory-associated proteins and pathways linked to adaptive stress remodeling or progression toward cytotoxic collapse.

Melitten↗

PubMedDate not supplied

Bacillus cereus-induced malabsorption in young mice.

Following a single, oral dose of Bacillus cereus (2 X 10(8) bacteria) in vitro intestinal absorption of D-glucose, D-galactose, L-arginine, L-histidine, L-ornithine and L-proline in young mice (aged 2--3 1/2 months) decreased. Malabsorption of D-glucose was dose- and time-dependent. Impaired absorption of D-glucose occurred throughtout the length of the small intestine, particularly distally. Following hydrolysis of D-maltose at the brush border, D-glucose absorption in infected mice and that of the untreated controls was similar. Using D-glucose, fluid transfer in the infected intestine and that of the controls was alike. Although slightly lower, fluid transfer in the infected intestine using the other solutes was not significantly different compared with the controls. Glucose-dependent and glucose-independent intestinal fluid transfer in infected animals was like that of the controls. Using old infected mice (aged 8--9 months) intestinal absorption of D-glucose and L-histidine was unchanged compared with young mice. The fresh small intestinal weight in infected mice and the controls was alike. Changes in the histology of the small intestine in young infected mice were small and inconsistent.

Age Factors↗

PubMed2025

Identification of radiation-sensitive genes as biomarkers for biodosimetry: an ex vivo analysis of TNFRSF10B, ZMAT3, POLH, and PLK2 in human blood samples.

BACKGROUND: Humans are exposed to ionizing radiation (IR), which causes direct and indirect DNA damage. Biodosimetry is a critical component of clinical care following radiation exposure, enabling accurate assessment and mitigation of health effects. The present study was conducted to investigate the ex vivo expression of the genes TNFRSF10B, ZMAT3, PLK2, and POLH in human peripheral blood samples exposed to X-radiation at doses of 0, 0.5, 2, and 4 Gy at 0, 4, 24, and 48 hours post-exposure. Investigating gene expression dynamics through biodosimetry is a novel approach that may provide insights into gene-specific responses, potentially enhancing the accuracy and sensitivity of radiation dose assessment. MATERIALS AND METHODS: Peripheral blood samples were collected from five healthy volunteers and exposed to 0, 0.5, 2, or 4 Gy radiation with a 6 MV linear accelerator. Following the extraction of RNA and cDNA synthesis, gene expression analysis via qRT‒PCR was performed. These genes were normalized against the housekeeping gene β-actin, and the ΔΔCt method was used for statistical analysis of gene expression. The data were subjected to statistical analysis, and the level of significance (p < 0.05) was determined to test the effects of dose and time on gene expression. RESULTS: The expression of the TNFRSF10B, ZMAT3, POLH, and PLK2 genes was markedly dose- and time-dependent in response to X-ray radiation in vitro. Whole-blood samples irradiated at doses of 0, 0.5, 2, and 4 Gy and analyzed at four time points, 0, 4, 24, and 48 hours, respectively, revealed marked changes in the expression levels of the genes studied, revealing the mechanisms of the response at the cellular level to ionizing radiation. Although minor inter-individual variation in gene expression was observed, it did not significantly affect the overall trends, and the results remained statistically robust. CONCLUSION: These findings highlight a robust biodosimetry framework: TNFRSF10B demonstrated the highest diagnostic performance (AUC = 0.94; sensitivity = 98%; specificity = 75%; cut-off = 1.11), making it a highly reliable biomarker for radiation exposure. PLK2 also exhibited strong discriminative capacity (AUC = 0.84; sensitivity = 90%; specificity = 80%; cut-off =2.5), particularly for minimizing false positives. ZMAT3 (AUC = 0.78; sensitivity/specificity = 75%; cut-off = 3.21) showed balanced early-phase performance, whilePOLH (AUC = 0.73; sensitivity = 80%; specificity = 60%; cut-off = 1.10) may serve as a complementary marker. Collectively, these findings support a multi-gene expression approach for accurate biodosimetric assessment and improved triage following radiation exposure.

Humans↗

PubMed1979

[Effect of the time of theophylline administration on the intensity of diuresis and natriuresis in the rat].

The present study originates in two experimental data: circadian variations evidence of water, electrolytes and solutes urinary excretion and theophylline diuretic and salidiuretic effects knowledge; we purpose to evidence theophylline-induced water and sodium renal excretion in rats as modified by the time of drug administration. Theophylline single dose is injected in 100 animals (20 lots of 5 rats) at 8 h, 14 h, 20 h or 2 h and urines are collected during a consecutive to injection hours long period: 8 h-14 h (I), 14 h-20 h (II), 20 h-2 h (III) or 2 h-8 h (IV). Diuresis increases in + 40,4 p. cent (I), in + 123,7 p. cent (II), in + 123,3 p. cent (III) in + 65,4 p. cent (IV). So, natriuresis increases in 39,6 p. cent (I), in 223,2 p. cent (II), in 114,3 p cent (III) and in 109,6 p. cent (IV). These results evidence that theophylline diuretic and natriuretic effects change strongly with injection time, being largest if it is injected at 14 h and slightest if injected at 8 h. Such observations prompt to study if the other pharmacological properties of theophylline, especially at pulmonary level, response also with a time-dependant intensity.

Animals↗